Publications by authors named "Nwokocha Chukwuemeka"

40 Publications

Nutraceutical management of metabolic syndrome as a palliative and a therapeutic to coronavirus disease (COVID) crisis.

Arch Physiol Biochem 2021 Mar 26:1-20. Epub 2021 Mar 26.

Department of Basic Medical Sciences (Physiology Section), The University of the West Indies, Mona, Jamaica.

The global market for medicinal plants and herbs is on the increase due to their desirability, efficacy, and less adverse effects as complementary and alternative medications to the orthodox pharmaceuticals, perhaps due to their natural components and qualities. Metabolic syndromes are managed with changes in diet, exercise, lifestyle modifications and the use of pharmacological agents. Plants are now known to have potent antioxidant and cholinergic activities which are relevant to the management of several metabolic syndromes, which are unfortunately, co-morbidity factors in the coronavirus disease crisis. This review will focus on the biological activities of some plant products used as complementary and alternative medicines in the management of metabolic syndromes, and on their reported antiviral, antithrombotic, angiotensin-converting enzyme inhibitory properties, which are integral to their usage in the management of viral infections and may give an avenue for prophylactic and therapeutics especially in the absence of vaccines/formulated antiviral therapies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/13813455.2021.1903041DOI Listing
March 2021

Tert-butylhydroquinone attenuates doxorubicin-induced dysregulation of testicular cytoprotective and steroidogenic genes, and improves spermatogenesis in rats.

Sci Rep 2021 Mar 9;11(1):5522. Epub 2021 Mar 9.

Department of Physiology, School of Medical Sciences, Universiti Sains Malaysia, 16150, Kubang Kerian, Kelantan, Malaysia.

Doxorubicin (DOX) is a broad-spectrum chemotherapeutic drug used in the treatment of cancers. It acts by generating reactive oxygen species in target cells. The actions are, however, not limited to cancerous cells as it attacks healthy cells, killing them. This study investigated the benefits of the antioxidant, tert-butylhydroquinone (tBHQ), on testicular toxicity following DOX therapy. Twenty-four adult male albino rats were assigned randomly into four groups (n = 6), namely: normal control (NC), tBHQ, DOX and tBHQ + DOX groups. tBHQ (50 mg/kg body weight in 1% DMSO) was administered orally for 14 consecutive days, while a single DOX dose (7 mg/kg body weight) was administered intraperitoneally on Day 8. DOX decreased sperm count, motility and viability, and decreased the levels of steroidogenesis-related proteins, and reproductive hormones. Furthermore, DOX decreased the expression of antioxidant cytoprotective genes, and decreased the protein level of proliferating cell nuclear antigen in the testis. Conversely, DOX increased the expression of pro-inflammatory and pro-apoptotic genes in the testis. These negative effects were ameliorated following the intervention with tBHQ. Our results suggest that tBHQ protects the testis and preserves both steroidogenesis and spermatogenesis in DOX-treated rats through the suppression of oxidative stress, inflammation and apoptosis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-021-85026-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7970903PMC
March 2021

Cerebrospinal Fluid Biomarkers of Alzheimer's Disease: Current Evidence and Future Perspectives.

Brain Sci 2021 Feb 10;11(2). Epub 2021 Feb 10.

Department of Basic Medical Sciences, Faculty of Medical Sciences, The University of the West Indies, Kingston 7, Jamaica.

Alzheimer's disease is a progressive, clinically heterogeneous, and particularly complex neurodegenerative disease characterized by a decline in cognition. Over the last two decades, there has been significant growth in the investigation of cerebrospinal fluid (CSF) biomarkers for Alzheimer's disease. This review presents current evidence from many clinical neurochemical studies, with findings that attest to the efficacy of existing core CSF biomarkers such as total tau, phosphorylated tau, and amyloid-β (Aβ), which diagnose Alzheimer's disease in the early and dementia stages of the disorder. The heterogeneity of the pathophysiology of the late-onset disease warrants the growth of the Alzheimer's disease CSF biomarker toolbox; more biomarkers showing other aspects of the disease mechanism are needed. This review focuses on new biomarkers that track Alzheimer's disease pathology, such as those that assess neuronal injury (VILIP-1 and neurofilament light), neuroinflammation (sTREM2, YKL-40, osteopontin, GFAP, progranulin, and MCP-1), synaptic dysfunction (SNAP-25 and GAP-43), vascular dysregulation (hFABP), as well as CSF α-synuclein levels and TDP-43 pathology. Some of these biomarkers are promising candidates as they are specific and predict future rates of cognitive decline. Findings from the combinations of subclasses of new Alzheimer's disease biomarkers that improve their diagnostic efficacy in detecting associated pathological changes are also presented.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/brainsci11020215DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7916561PMC
February 2021

Maca extracts and estrogen replacement therapy in ovariectomized rats exposed at high altitude.

Reprod Med Biol 2021 Jan 11;20(1):88-95. Epub 2020 Nov 11.

Department of Basic Medical Sciences Faculty of Medical Sciences The University of the West Indies Kingston Jamaica.

Purpose: Hormone Replacement Therapy (HRT) and herbal remedies are often used to alleviate menopausal symptoms, but their effects and efficacy at high altitudes presents with several uncertainties. The purpose of this study was to evaluate whether pre-treatment with maca ( Walp) improved the tolerance to high altitude on an ovariectomized (OVX) rat model at sea level.

Method: The animals were treated with 17β-estradiol (200 µg/kg; E2), red and black maca (1.5 g/kg) for 28 days and exposed at high altitude or sea level.

Result: Our findings showed that red and black maca extracts significantly ( < .001) reduced the MDA level in OVX rat serum under hypoxia in a similar way to E2. Red and black maca extracts had similar effects with E2, by significantly ( < .001) reversing and increasing the ovariectomized induced decrease in cornified endometrial cell number. Under hypoxic conditions, the black maca ( < .05) and E2 ( < .01) increased the uterine weight in OVX rats. Finally, E2 alone significantly recovered the frequency of the uterine contractile response.

Conclusion: Aqueous extract of partially protects the reproductive function in hypobaric hypoxic environment, through the recovery of the cornified endometrial cells and uterine weight in a menopausal model of OVX rats.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/rmb2.12357DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7812464PMC
January 2021

Metabolomic Profiling of Mango ( Linn) Leaf Extract and Its Intestinal Protective Effect and Antioxidant Activity in Different Biological Models.

Molecules 2020 Nov 5;25(21). Epub 2020 Nov 5.

Departamento de Química, Facultad de Ciencias Básicas, Universidad de Antofagasta, Antofagasta 1271155, Chile.

Linn popularly known as mango is used in folk medicine to treat gastrointestinal disorders. The aim of this study was to identify the metabolomic composition of lyophilized extract of mango leaf (MIE), to evaluate the antioxidant activity on several oxidative stress systems (DPPH, FRAP, TBARS, and ABTS), the spasmolytic and antispasmodic activity, and intestinal protective effect on oxidative stress induced by HO in rat ileum. Twenty-nine metabolites were identified and characterized based on their ultra-high-performance liquid chromatography (UHPLC) high-resolution orbitrap mass spectrometry, these include: benzophenone derivatives, xanthones, phenolic acids, fatty acids, flavonoids and procyanidins. Extract demonstrated a high antioxidant activity in in-vitro assays. MIE relaxed ( < 0.001) intestinal segments of rat pre-contracted with acetylcholine (ACh) (10 M). Pre-incubation of intestinal segments with 100 µg/mL MIE significantly reduced ( < 0.001) the contraction to HO. Similar effects were observed with mangiferin and quercetin (10 M; < 0.05) but not for gallic acid. Chronic treatment of rats with MIE (50 mg/kg) for 28 days significantly reduced ( < 0.001) the HO-induced contractions. MIE exhibited a strong antioxidant activity, spasmolytic and antispasmodic activity, which could contribute to its use as an alternative for the management of several intestinal diseases related to oxidative stress.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/molecules25215149DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7663946PMC
November 2020

Hypotensive and antihypertensive effects of an aqueous extract from Guinep fruit (Melicoccus bijugatus Jacq) in rats.

Sci Rep 2020 10 29;10(1):18623. Epub 2020 Oct 29.

Department of Environmental and Interdisciplinary Sciences, College of Science, Engineering and Technology, Texas Southern University, Houston, TX, 77004, USA.

Melicoccus bijugatus Jacq (Mb) has been reported to have cardiovascular modulatory effects. In this study, we evaluated the antihypertensive effects and mechanism of action of Mb on N-Nitro-L-arginine Methyl Ester (L-NAME) and Deoxycorticosterone Acetate (DOCA) rat models. Aqueous extract of Mb fruit (100 mg/kg) was administered for 6 weeks to rats by gavage and blood pressure was recorded. Effects of the extract on vascular reactivity was evaluated using isolated organ baths, and tissues were collected for biochemical and histological analysis. The systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP) were significantly (P < 0.05) reduced with extract (100 mg/kg) administration and treatment compared to the hypertensive models. Mb (100 µg/mL) reduced the vascular contractility induced by phenylephrine (PE), and caused a dose-dependent relaxation of PE-induced contraction of aortic vascular rings. The vasorelaxation properties seemed to be endothelium dependent, as well as nitric oxide (NO) and guanylyl cyclase, but not prostaglandin dependent. Histomicrograph of transverse sections of the ventricles from the Mb group did not show abnormalities. The extract significantly (P < 0.05) reduced an L-NAME induced elevation of cardiac output and Creatine Kinase Muscle-Brain (CKMB), but had no significant impact on the activities of arylamine N-acetyltransferase. In conclusion, Mb significantly decreased blood pressure in hypertensive models. The extract possesses the ability to induce endothelium dependent vasodilation, which is dependent on guanylyl cyclase but not prostaglandins.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-020-75607-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7596469PMC
October 2020

Impact of the Potential Antitumor Agent 2-(4-Hydroxyphenyl) Amino-1,4-Naphthoquinone (Q7) on Vasomotion Is Mediated by the Vascular Endothelium, But Not Vascular Smooth Muscle Cell Metabolism.

J Cardiovasc Pharmacol 2021 Feb;77(2):245-252

Laboratorio de Fisiología Experimental, Instituto Antofagasta, Universidad de Antofagasta, Antofagasta, Chile.

Abstract: Vasomotion is defined as rhythmic oscillations in arterial diameter that regulate the blood flow and blood pressure. Because antitumor treatment may impair vascular functions and increase the blood pressure, we sought to evaluate whether a new naphthoquinone derivative, postulated as an antitumor agent, manifests adverse effects on vascular function. In this article, we evaluated the toxicity of 2-(4-hydroxyphenyl) amino-1,4-naphthoquinone (Q7) and its effects on vascular vasomotion in 3 models of vascular structure: endothelial cells, aortic ring, and smooth muscle cells. Although showing nontoxic effects, Q7 inhibited the formation of capillary-like structures of the EA.hy926 endothelial cell line grown on Matrigel. In exvivo experiments with aortic rings precontracted with phenylephrine (PE, 10-6 M), Q7 (10-5 M) significantly (P < 0.05) reduced vascular rhythmic contractions induced by the acetylcholine (ACh; 10-7-10-5 M), whereas sodium nitroprusside (a nitric oxide donor; 10-8 M) recovered the vasomotion. Furthermore, Q7 (10-5 M) did not decrease KCl-induced vascular rhythmic contractions in the aortic rings precontracted with BaCl2 (a nonselective K+ channel blocker; 10-3 M). Vascular smooth muscle cells (A7r5) preincubated with Q7 (10-5 M) for 3 hours also demonstrated a reduced glucose uptake. However, the Adenosine Triphosphate content was unaffected, suggesting that the rapid reduction in vasomotion observed in vascular reactivity experiments did not involve cellular metabolism but may be due to faster mechanisms involving endothelial nitric oxide and K+ channels leading to oscillations in intracellular Ca2+. In summary, the naphthoquinone derivative Q7 presents low cytotoxicity yet may alter the endothelial cell response and vasomotion in the absence of changes in smooth muscle cell metabolism.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/FJC.0000000000000940DOI Listing
February 2021

Relaxation Responses of Ketamine and Propofol to Vasoactive Agents in Streptozotocin-Induced Diabetic Rats.

Niger J Physiol Sci 2020 Jun 30;35(1):33-39. Epub 2020 Jun 30.

University of The West Indies Mona.

Diabetes mellitus (DM) is a major risk factor for the development of endothelial dysfunction which affects the ability of blood vessels to regulate vascular tone. The study aimed to investigate the mechanisms of vasodilator action of the anaesthetic agents ketamine and propofol in diabetic rat aorta. 30 male Sprague-Dawley rats were randomly divided into two equal groups: (i) non-diabetic control (ii) Streptozotocin-induced diabetic group. DM was induced by a single intra-peritoneal injection of streptozotocin at 50 mg/kg body weight.  Blood samples were taken from the tail vein after 24 hours and tested for glucose level using an automated glucose analyser. A blood glucose ≥10 mmol/L confirmed hyperglycaemia and the development of DM.  Rats were  sacrificed, and the aortae excised.  The vascular responses of  aortic rings from both groups to ketamine, propofol in the presence of  vasoactive agents  were studied using standard organ bath procedures. Ketamine and propofol reduced Phe-induced contraction similarly in the diabetic and control groups. Barium chloride, attenuated the relaxation response to propofol in diabetic aorta when compared to ketamine. 4-aminopyridine significantly attenuated the relaxation response to ketamine and propofol in diabetic aorta. Glibenclamide, significantly reduced  ketamine-induced relaxation in diabetic aorta when compared to propofol. Activation of K+ channels with nicorandil or NS1619 did not affect the relaxation response to ketamine or propofol in diabetic aorta. The results recommend that propofol can be effective in mitigating the consequences of hemodynamic instability in glibenclamide treated diabetics when compared to ketamine. This response is mediated by propofol-induced inhibition of intracellular calcium influx.
View Article and Find Full Text PDF

Download full-text PDF

Source
June 2020

Medicinal Herbs Used in Traditional Management of Breast Cancer: Mechanisms of Action.

Medicines (Basel) 2020 Aug 14;7(8). Epub 2020 Aug 14.

Department of Pathology, Faculty of Medical Sciences, The University of the West Indies, Kingston 7, Jamaica.

: Breast cancer is one of the principal causes of death among women and there is a pressing need to develop novel and effective anti-cancer agents. Natural plant products have shown promising results as anti-cancer agents. Their effectiveness is reported as decreased toxicity in usage, along with safety and less recurrent resistances compared with hormonal targeting anti-cancer agents. : A literature search was conducted for all English-language literature published prior to June 2020. The search was conducted using electronic databases, including PubMed, Embase, Web of Science, and Cochrane Library. The search strategy included keywords such as breast cancer, herbs, anti-cancer biologically active components, clinical research, chemotherapy drugs amongst others. : The literature provides documented evidence of the chemo-preventative and chemotherapeutic properties of Ginseng, garlic (Allium sativum), Black cohosh (Actaea racemose), Tumeric (Curcuma longa), Camellia sinenis (green tea), Echinacea, Arctium (burdock), Flaxseed (Linum usitatissimum) and Black Cumin (Nigella sativa). : The nine herbs displayed anti-cancer properties and their outcomes and mechanisms of action include inhibition of cell proliferation, angiogenesis and apoptosis as well as modulation of key intracellular pathways. However, more clinical trials and cohort human studies should be conducted to provide key evidence of their medical benefits.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/medicines7080047DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7460502PMC
August 2020

Tert-butylhydroquinone preserve testicular steroidogenesis and spermatogenesis in cisplatin-intoxicated rats by targeting oxidative stress, inflammation and apoptosis.

Toxicology 2020 08 18;441:152528. Epub 2020 Jun 18.

Department of Physiology, College of Medical Sciences, University of Calabar, P.M.B. 1115 Calabar, Cross River State, Nigeria.

Cisplatin (Cis) is an effective chemotherapeutic intervention against many cancer types. However, the oxidative stress-related toxicities associated with cancer cell resistance-induced dose scaling has limited its long-term use. In the present study, we explored the benefits of the antioxidant, tert-butylhydroquinone (tBHQ; 50 mg/kg b.w./day, for 14 days) against Cis single dose injection (7 mg/kg b.w., i.p on Day 8), on testicular toxicity of male Wistar rats. Cis triggered testicular and epididymal oxidative stress, testicular inflammation (upregulated NF-κB, TNF-α and IL-1β mRNA levels, and downregulated IL-10 mRNA level), increased testicular apoptosis (increased Bax/Bcl2 and caspase-3 mRNA levels) and decreased testicular germ cells proliferation. Further, Cis decreased testicular steroidogenesis (decreased expression of StAR, CYP11A1, 3β-HSD and 17β-HSD mRNA and proteins) and decreased follicle stimulating hormone, luteinizing hormone and testosterone levels. Cis also decreased sperm count, motility, viability, normal morphology and Johnsen score. However, intervention with tBHQ significantly decreased oxidative stress by upregulating Nrf2 gene, suppressed inflammation, apoptosis and increased testicular germ cells proliferation. tBHQ also increased steroidogenesis and improved sperm parameters. Taken together, tBHQ improves steroidogenesis and spermatogenesis in Cis-intoxicated rats by improving antioxidant status, dampening inflammation and apoptosis, thus improving the proliferative capacity of spermatogenic cells.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.tox.2020.152528DOI Listing
August 2020

May measurement month 2017: Latin America.

J Hypertens 2020 06;38(6):1183-1188

Imperial College London, London, UK.

Objectives: To raise awareness of blood pressure, measured by number of countries involved, number of people screened, and number of people who have untreated or inadequately treated hypertension.

Methods: An opportunistic cross-sectional survey of volunteers aged at least 18 years was carried out in May 2017. Blood pressure measurement, the definition of hypertension and statistical analysis followed the standard May measurement month protocol. Eighteen countries in Latin America and the Caribbean participated in the campaign, providing us with a wide sample for characterization.

Results: During May measurement month 2017 in Latin America and the Caribbean, 105 246 individuals were screened. Participants who had cardiovascular disease, 2245 (2.3%) had a prior myocardial infarction, and 1711 (1.6%) a previous stroke, additionally 6760 (6.4%) individuals were diabetic, 7014 (6.7%) current smokers and 9262 (8.8%) reported alcohol intake once or more per week. Mean SBP was 122.7 mmHg and DBP was 75.6 mmHg. After imputation, 42 328 participants (40,4%) were found to be hypertensive.

Conclusion: The high numbers of participants detected with hypertension and the relatively large proportion of participants on antihypertensive treatment but with uncontrolled hypertension reinforces the importance of this annual event in our continent, to raise awareness of the prevention of cardiovascular events.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/HJH.0000000000002370DOI Listing
June 2020

The Malaria-High Blood Pressure Hypothesis: Revisited.

Am J Hypertens 2020 08;33(8):695-702

Department of Physiology, College of Medical Sciences, University of Benin, Benin City, Nigeria.

Malaria etiologies with pathophysiological similarities to hypertension currently constitute a major subject of research. The malaria-high blood pressure hypothesis is strongly supported by observations of the increasing incidence of hypertension in malaria-endemic, low- and middle-income countries with poor socioeconomic conditions, particularly in sub-Saharan African countries. Malnutrition and low birth weight with persistent symptomatic malaria presentations in pregnancy correlate strongly with the development of preeclampsia, gestational hypertension and subsequent hypertension in adult life. Evidence suggest that the link between malaria infection and high blood pressure involves interactions between malaria parasites and erythrocytes, the inflammatory process, effects of the infection during pregnancy; effects on renal and vascular functions as well as effects in sickle cell disease. Possible mechanisms which provide justification for the malaria-high blood pressure hypothesis include the following: endothelial dysfunction (reduced nitric oxide (NO) levels), impaired release of local neurotransmitters and cytokines, decrease in vascular smooth muscle cell viability and/or alterations in cellular calcium signaling leading to enhanced vascular reactivity, remodeling, and cardiomyopathies, deranged homeostasis through dehydration, elevated intracellular mediators and proinflammatory cytokine responses, possible genetic regulations, activation of the renin-angiotensin-aldosterone system mechanisms and renal derangements, severe anemia and hemolysis, renal failure, and end organ damage. Two key mediators of the malaria-high blood pressure association are: endothelial dysfunction (reduced NO) and increased angiotensin-converting enzyme activity/angiotensin II levels. Sickle cell disease is associated with protection against malaria infection and reduced blood pressure. In this review, we present the state of knowledge about the malaria-blood pressure hypothesis and suggest insights for future studies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/ajh/hpaa051DOI Listing
August 2020

Blood pressure-reducing activity of Gongronema latifolium Benth. (Apocynaeceae) and the identification of its main phytochemicals by UHPLC Q-Orbitrap mass spectrometry.

J Basic Clin Physiol Pharmacol 2019 Aug 14;31(1). Epub 2019 Aug 14.

Department of Basic Medical Sciences, Faculty of Medical Sciences, University of the West Indies, Kingston, Jamaica.

Background Gongronema latifolium Benth. (family Apocynaceae) leaves (GL) has interesting medicinal properties. The effects of extracts from G. latifolium on blood pressure (BP) and the possible mechanisms of action were also investigated. Methods The ultrahigh resolution liquid chromatography orbitrap MS analysis was used to identify the phytochemicals present. Normotensive Wistar rats were anesthetized with sodium pentobarbitone (40 mg/kg) intraperitoneally, and the jugular vein was cannulated for infusion of drugs while the carotid artery was cannulated for direct BP measurement. GL extract (5-20 mg) alone or with nifedipine (10 mg/kg), atropine (2 mg/kg), L-NAME (5 mg/kg), methyl blue (3 mg/kg) and propranolol (1 mg/kg) were administered intravenously to Wistar rats and direct BP measurements were carried out. Results Systolic and diastolic BP levels (128/90 mm Hg; MAP 103 ± 3 mm Hg) and heart rates were all significantly (p < 0.01) decreased after GL administration. Raised mean arterial pressure (MAP) and heart rate by atropine, L-NAME and methyl blue were significantly (p < 0.01) reduced after GL administration, while propranolol significantly (p < 0.01) inhibited hypotension caused by GL. Infusion of GL reduced MAP (95 ± 3 mm Hg) comparable with nifedipine (93 ± 2 mm Hg), a calcium channel blocker. The phytochemicals identified were 34 compounds, including oleanolic acid derivatives, flavonoids, antioxidant fatty acids, 2 coumarins and 2 iridoids. Conclusions These results suggest that G. latifolium has hypotensive properties mediated by the synergistic activity of the compounds, probably via the β-adrenergic blockade mechanism.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1515/jbcpp-2018-0178DOI Listing
August 2019

Aristoteline, an Indole-Alkaloid, Induces Relaxation by Activating Potassium Channels and Blocking Calcium Channels in Isolated Rat Aorta.

Molecules 2019 Jul 29;24(15). Epub 2019 Jul 29.

Laboratorio de Fisiología Experimental, Instituto Antofagasta, Universidad de Antofagasta, Antofagasta 1270300, Chile.

Alkaloids derived from plants have shown great medicinal benefits, and are often reported for their use in cardiovascular disease management. (Molina) Stuntz (Maqui) has shown important medicinal properties in traditional useage. In this study, we evaluated the effect of the indole-alkaloid aristoteline (ARI), isolated from leaves of Maqui, on vascular reactivity of isolated aortic rings from normotensive rats. ARI induced relaxation (100%) in a concentration-dependent manner in intact or denuded-endothelium aortic rings pre-contracted with phenylephrine (PE; 1 μM). However, a specific soluble guanylyl cyclase inhibitor (ODQ; 1 μM) significantly reduced the relaxation to ARI in aortic rings pre-contracted with PE. In the presence of ARI, the contraction induced by KCl or PE was significantly (p < 0.05) decreased. Interestingly, the potassium channel blockade with 10 μM BaCl (Kir), 10 μM glibenclamide (K), 1 mM tetraethylammonium (TEA; KCa1.1), or 1 mM 4-aminopyridine (4-AP; Kv) significantly ( < 0.05) reduced the ARI-induced relaxation. ARI significantly ( < 0.05) reduced the contractile response to agonist of Ca1.2 channels (Bay K8644; 10 nM), likely reducing the influx of extracellular calcium through plasma membrane. The mechanisms associated with this process suggest an activation of the potassium channels, a calcium-induced antagonism and endothelium independent vasodilation that possibly involves the nitric oxide-independent soluble guanylate cyclase pathway.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/molecules24152748DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6695676PMC
July 2019

Blood Pressure Screening Campaign in Jamaica: May Measurement Month 2017.

Am J Hypertens 2019 11;32(12):1186-1191

Department of Basic Medical Sciences, The University of the West Indies, Mona, Jamaica.

Background: Hypertension (HTN) is responsible for a significant disease burden in Jamaica. We are reporting the results of the 2017 blood pressure (BP) screening campaign May Measurement Month in Jamaica that aimed to increase the awareness of HTN.

Methods: Adults, 18 years old and older, from different parishes of Jamaica were invited to participate during May to June 2017. Demographic data were collected. BP, weight, and height were measured and recorded.

Results: Five hundred sixty-six participants (n = 566) were enrolled, 91.6% (519) from urban areas, and 72.6% (410) were females. The average age was 53.7 (18-95) years old and body mass index was 28.2 ± 6.6 kg/m2. The prevalence of HTN was 47.3% (267/566), without gender or living areas differences (both P > 0.1). Prevalence of HTN was lower in those who self-identified as Interracial ethnicity, in comparison with Afro-Caribbean (33% vs. 48.3%; P = 0.04). About third of the hypertensive patients were not aware of the high BP (89/267; 35.6%). Between hypertensive patients, 64.4% (172/267) were receiving antihypertensive drugs. The rate of BP control was 32% of the hypertensive patients and 50% of those receiving antihypertensive medication. Significant lower BP control was observed between diabetic vs. nondiabetic patients (34.3% vs. 60%; P < 0.001).

Conclusion: We found a high prevalence of HTN in this population, especially in patients with diabetes or previous cardiovascular diseases. We report an increase in HTN awareness in Jamaica but more advances need to be performed to increase HTN treatment and control.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/ajh/hpz117DOI Listing
November 2019

Modulatory Effect of Guinep ( Jacq) Fruit Pulp Extract on Isoproterenol-Induced Myocardial Damage in Rats. Identification of Major Metabolites Using High Resolution UHPLC Q-Orbitrap Mass Spectrometry.

Molecules 2019 Jan 10;24(2). Epub 2019 Jan 10.

Laboratorio de Fisiología Experimental, Instituto Antofagasta, Universidad de Antofagasta, Antofagasta 1270300, Chile.

Guinep is traditionally used in the management of cardiovascular ailments. This study aims to evaluate its medicinal constituents and effects in the management of myocardial injury in an experimental isoproterenol (ISO) rat model. Sprague-Dawley rats were randomly assigned to four groups: Group 1 was the control group; Group 2 received extract (100 mg/Kg; MB) for six weeks; Group 3 was given ISO (85 mg/Kg) i.p. twice during a 24-hour period; and Group 4 was given ISO (85 mg/Kg) i.p. and MB extract (100 mg/Kg) for six weeks. The MB was administered orally by gavage, daily. The blood pressure of conscious animals was measured, while ECG was performed under anesthesia. Blood and serum were collected for biochemical and hematological analysis. The ISO group treated with MB showed a significant decrease ( < 0.001) in (SBP), diastolic (DBP), mean arterial (MAP) and heart rate (HR) compared to the ISO only group. Conversely, MB treated rats that were not induced with ISO displayed a significant decreases ( < 0.001) in SBP, DBP, MAP, and HR. ISO significantly elevated the ST segment ( < 0.001) and shortened the QTc interval ( < 0.05), which were recovered after treatment with 100 mg/Kg of MB. In addition, the results showed a significant decrease ( < 0.001) in the heart to body weight ratio of the ISO group treated with MB compared to the ISO only group. Furthermore, the extract normalized the hematological values depressed by the ISO while significantly elevating the platelet count. UHPLC high-resolution orbitrap mass spectrometry analysis results revealed the presence of several antioxidants like vitamin C and related compounds, phenolic acids, flavonoid, fatty acids (oxylipins), and terpene derivatives. The results of this study indicated that did display some cardio-protective effects in relation to myocardial injury.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/molecules24020235DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6359499PMC
January 2019

8-Oxo-9-Dihydromakomakine Isolated from Induces Vasodilation in Rat Aorta: Role of the Extracellular Calcium Influx.

Molecules 2018 Nov 21;23(11). Epub 2018 Nov 21.

Departamento de Ciencias Químicas y Recursos Naturales, Facultad de Ingeniería, Universidad de La Frontera, Temuco 4780000, Chile.

8-Oxo-9-dihydromakomakine is a tetracyclic indole alkaloid extracted from leaves of the Chilean tree . The present study investigated the effects of this alkaloid on vascular response in tissues isolated from aortic segments obtained from normotensive rats. Our results showed that 8-oxo-9-dihydromakomakine induced a dose-dependent relaxation of aortic rings pre-contracted with phenylephrine (PE; 10 M). The vasorelaxation induced by 8-oxo-9-dihydromakomakine in rat aortic rings is independent of endothelium. The pre-incubation of aortic rings with 8-oxo-9-dehydromakomakine (10 M) significantly reduced the contractile response to KCl ( < 0.001) more than PE ( < 0.05). The highest dose of 8-oxo-9-dehydromakomakine (10 M) drastically reduced the contraction to KCl (6·10 M), but after that, PE (10 M) caused contraction ( < 0.05) in the same aortic rings. The addition of 8-oxo-9-dihydromakomakine (10 M) decreased the contractile response to tetraethylammonium (a voltage-dependent potassium channels blocker; TEA; 5 × 10 M; < 0.01) and BaCl₂ (a non-selective inward rectifier potassium channel blocker; 5 × 10 M; < 0.001) in rat aorta. 8-oxo-9-dihydromakomakine (10 M) decreased the contractile response to PE in rat aorta in the presence or absence of ouabain (an inhibitor of Na,K-ATPase; 10 M; < 0.05). These results could indicate that 8-oxo-9-dihydromakomakine partially reduces plasma membrane depolarization-induced contraction. In aortic rings depolarized by PE, 8-oxo-9-dihydromakomakine inhibited the contraction induced by the influx of extracellular Ca in a Ca free solution ( < 0.01). 8-oxo-9-dihydromakomakine reduced the contractile response to agonists of voltage-dependent calcium channels type L (Bay K6844; 10 M; < 0.01), likely decreasing the influx of extracellular Ca through the voltage-dependent calcium channels. This study provides the first qualitative analysis indicating that traditional folk medicine may be protective in the treatment of cardiovascular pathologies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/molecules23113050DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6278248PMC
November 2018

Vasodilator and hypotensive effects of pure compounds and hydroalcoholic extract of Xenophyllum poposum (Phil) V.A Funk (Compositae) on rats.

Phytomedicine 2018 Nov 26;50:99-108. Epub 2018 Sep 26.

Laboratorio de Química Biológica, Instituto Antofagasta (IA), Universidad de Antofagasta, Antofagasta, Chile.

Background: Xenophyllum poposum is an endemic species of the Andes Cordillera, popularly known as Popusa. Popusa is widely used by mountain communities as a folk medicine to treat altitude sickness and hypertension.

Purpose: The aim of this study is to evaluate the hypotensive effects and vascular reactivity of Popusa extracts and its pure isolated compounds.

Methods: Hydroalcoholic extract of Xenophyllum poposum (HAE X. poposum; 40 mg/kg dose) were administered to rats by gavage and mean arterial pressures were recorded. Organ bath studies were conducted in endothelium-intact and denuded rings, and the vascular reactivity of the HAE X. poposum extract and its isolated compounds were compared and analysed. Cytosolic Ca was measured in vascular smooth muscle cell line A7r5 using Fura2-AM.

Results: HAE X. poposum significantly reduced the mean arterial blood pressure and heart rate in normotensive rats chronically treated with the extract, as well as mice acutely treated with the extract. A negative chronotropic effect was observed in the isolated rat heart. HAE X. poposum induced endothelial vasodilation mediated by nitric oxide (NO), reduced the contractile response to PE, and decreased PE-induced intracellular Ca influx in vascular smooth muscle cells. Pure compounds isolated from HAE X. poposum such as 4‑hydroxy‑3-(3-methyl-2-butenyl) acetophenone, 5-acetyl-6‑hydroxy‑2-isopropenyl-2, and 3-dihydrobenzofurane (dihydroeuparin) also triggered endothelium-dependent vasodilation.

Conclusion: HAE X. poposum decreases blood pressure, heart rate and vascular response. The vasodilation properties of HAE X. poposum extract and its isolated compounds may act through the endothelial nitric oxide synthase, as well as calcium channel blocker mechanisms. The results of the present study provide the first qualitative analysis that supports the use of X. poposum in traditional folk medicine for the treatment of altitude sickness and hypertension.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.phymed.2018.09.226DOI Listing
November 2018

Ascorbate Attenuates Oxidative Stress and Increased Blood Pressure Induced by 2-(4-Hydroxyphenyl) Amino-1,4-naphthoquinone in Rats.

Oxid Med Cell Longev 2018 26;2018:8989676. Epub 2018 Jul 26.

Laboratorio de Fisiología Experimental (EPhyL), Instituto Antofagasta (IA), Universidad de Antofagasta, Antofagasta, Chile.

Quinone derivatives like 2-(4-hydroxyphenyl) amino-1,4-naphthoquinone (Q7) are used as antitumor agents usually associated with adverse effects on the cardiovascular system. The objective of this study was to evaluate the cardioprotective effect of ascorbate on Q7-induced cardiovascular response in Wistar rats. In this study, blood pressure, vascular reactivity, and intracellular calcium fluxes were evaluated in cardiomyocytes and the rat aorta. We also measured oxidative stress through lipid peroxidation (TBARS), superoxide dismutase- (SOD-) like activity, and HO generation. Oral treatment of rats with ascorbate (500 mg/kg) for 20 days significantly ( < 0.05) reduced the Q7-induced increase (10 mg/kg) in blood pressure and heart rate. The preincubation with ascorbate (2 mM) significantly ( < 0.05) attenuated the irregular beating of the atrium induced by Q7 (10 M). In addition, ascorbate induced endothelial vasodilation in the presence of Q7 in the intact aortic rings of a rat and reduced the cytosolic calcium levels in vascular smooth muscle cells. Ascorbate also reduced the Q7-induced oxidative stress . Ascorbate also attenuated Q7-induced SOD-like activity and increased TBARS levels. These results suggest a cardioprotective effect of ascorbate in animals treated orally with a naphthoquinone derivative by a mechanism involving oxidative stress.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1155/2018/8989676DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6083601PMC
December 2018

An evaluation of innovative community-based approaches and systematic tuberculosis screening to improve tuberculosis case detection in Ebonyi State, Nigeria.

Int J Mycobacteriol 2017 Jul-Sep;6(3):246-252

Department of Internal Medicine, Federal University Teaching Hospital, Abakaliki, Nigeria.

Background: National tuberculosis (TB) programmes globally rely heavily on passive case finding for detecting TB in the community as advocated by the World Health Organization (WHO). TB case detection is low in Nigeria despite improvement in TB services and coverage.

Methods: A retrospective evaluation of an active case-finding intervention utilizing community-based approaches and targeted systematic TB screening in Ebonyi State, Nigeria was done. The analysis was performed using Epi Info.

Results: Using community-based and health-facility-based systematic screening strategies, 218,751 persons were screened, with 19.7% of them being presumptive TB cases. Among these, 23,729 (55.1%) submitted sputum samples for microscopy, and 764 (3.2%) had smear-positive TB. In addition, 683 individuals were diagnosed with other forms of TB using X-ray and clinical evaluation giving a total of 1447 all forms of TB cases. The overall number needed to screen (NNS) to find one person with all forms of TB through the project was 151. The NNS was 53 for general outpatients, 88 through contact tracing, and 110 among HIV-infected persons.

Conclusions: Active case-finding strategies achieved good yields though early loss to follow-up was high. Active case finding is recommended for integration into national TB control policy and practice.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4103/ijmy.ijmy_91_17DOI Listing
April 2018

Aqueous extract from leaf of Artocarpus altilis provides cardio-protection from isoproterenol induced myocardial damage in rats: Negative chronotropic and inotropic effects.

J Ethnopharmacol 2017 May 22;203:163-170. Epub 2017 Mar 22.

Natural Products Institute, University of the West Indies, Mona Campus, Jamaica.

Ethnopharmacological Relevance: The leaves of Artocarpus altilis (Parkinson ex F.A.Zorn, Fosberg) (Moraceae) are used in the management of hypertension; this study assessed the cardio-protective effects of the leaf extract on isoproterenol (ISO) induced myocardial damage in rats.

Material And Methods: Twenty (20) adult male Sprague-Dawley rats (175-230g) were divided into 5 groups. Group 1 (Control), 2 (AA) received 50mg/Kg Artocarpus altilis (AA) only; 3 (ISO) received 85mg/Kg ISO only; 4 (ISO+AA/50) and 5 (ISO+AA/100) received 50 and 100mg/Kg AA respectively for 6 days, after induced with ISO twice (85mg/Kg) at a 24-h period. Blood pressure readings were taken before and after the administering of ISO using the tail cuff method. ECG was performed on anaesthetized rats. Cardiac contractility was measured in isolated right atrial muscles. Assessment of myocardial infarct (MI) size, heart/body weight ratio, biochemical, hematological and histo-morphological parameters were conducted at the end of seven days. An aqueous extract from leaves of A. altilis was analyzed for organic compounds using UHPLC mass spectrometry.

Results: ISO induced myocardial damage through an elevation of the heart rate (HR), infarct size and ECG distortions. Treatment with AA significantly (p˂0.05) reduced heart/body weight ratio (49%), MI (96%), HR (27%), sympathovagal imbalance (36%) and serum cardiac biomarkers (AST, LDH, HDL, triglycerides and CCK) caused by ISO. AA decreased the beat frequency of isolated right atrium (11%) cause by ISO, an action similar to propranolol (beta-adrenergic antagonist; 20%), but showed no significant changes in the QTc intervals of the ECG (suggesting no cardio-toxic drug-herb interactions), Thirty nine compounds were detected using high resolution LC-MS analysis (HPLC-Orbitrap-APCI-MS) in the extract. Pure compounds, as gallic acid and rutin, presented a higher negative chronotropic effect, similar to propranolol.

Conclusion: Oral administration of aqueous extract of Artocarpus artilis has cardio-protective functions in myocardial injury, in part, by decreasing the HR, reduced contractility and infarct size. These findings may explain the cardio-protective use of A. altilis in traditional medicine.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jep.2017.03.037DOI Listing
May 2017

Effect of Vitamin C Supplementation on Platelet Aggregation and Serum Electrolytes Levels in Streptozotocin-Induced Diabetes Mellitus in Rats.

Niger J Physiol Sci 2016 Aug 30;31(1):55-61. Epub 2016 Aug 30.

Department of Physiology, University of Calabar, Calabar.

Diabetes mellitus (DM) is a disease condition characterised by hyperglycemia; free radical and abnormalhaematological indices. Vitamin C can reduce free radical generation and ameliorate adverse conditions of diabetes mellitus.The aim of the present study is to investigate the effect of vitamin C on platelet aggregation and electrolyte levels in Type 1DM. Male Wistar rats were divided into four groups namely control, DM, DM +Vitamin C and Vitamin C groups. Rats weremade diabetic with a single dose of streptozotocin (65 mg/kg) intraperitoneally. Vitamin C was administered orally todiabetic and normal rats at 200 mg/kg body weight for 28 days. Blood samples were analyzed for hematological parameters,platelet aggregation, and serum electrolyte levels. Blood glucose in DM+ Vitamin C group (9.9 ± 1.8 mmol/L) wassignificantly reduced (p<0.01) compared to DM group (32.2 ± 2.1 mmol/L) and significantly higher (p<0.05) than control(4.4 ± 0.8 mmol/L). Haemoglobin (Hb) concentration in DM group (12 ± 0.1 g/dL) was significantly reduced (p<0.01) whencompared with control groups (14 ± 0.24 g/dL) and significantly increased (p<0.05) in the DM+vitamin C group (13.5 ± 0.5g/dL) compared with the diabetic group. The mean corpuscular volume values in DM (68.66 ± 0.5 fL) and DM+vitamin Cgroups (68.11 ± 0.4 fL) were significantly higher (p<0.01) than the control (59.49 ± 0.5fL). Platelet count in DM group (523± 8.5 x109/L) was significantly raised (p<0.01) when compared to control (356 ± 6.2 x109/L) and significantly reduced(p<0.01) in DM+ vitamin C-treated group (385 ± 7.8 x109/L) compared with DM group. Platelet aggregation and serumsodium/potassium ratios was significantly reduced (p<0.01) in DM+vitamin C compared with DM group. These resultssuggest that oral vitamin C administration increases haemoglobin, reduced plasma glucose level, platelet count, serumsodium/potassium ion ratio and inhibits platelet aggregation in streptozotocin-induced DM in rats.
View Article and Find Full Text PDF

Download full-text PDF

Source
August 2016

Hydroalcoholic extract and pure compounds from Senecio nutans Sch. Bip (Compositae) induce vasodilation in rat aorta through endothelium-dependent and independent mechanisms.

J Ethnopharmacol 2016 Nov 5;192:99-107. Epub 2016 Jul 5.

Laboratorio de Fisiología Experimental (EPhyL), Instituto Antofagasta (IA), Universidad de Antofagasta, Antofagasta, Chile.

Ethnopharmacological Relevance: Senecio nutans Sch. Bip. (Compositae) is an endemic plant of South America, and is used in herbal medicine in Andean communities for treating acute mountain sickness. Currently, the direct effects of hydroalcoholic extract of S. nutans (HAE S. nutans) or its isolated compounds on the vascular system are not well described. The aim of this study was to determine the effects and mechanism of action of S. nutans on vascular function in healthy rats.

Material And Methods: Seven compounds were isolated from the HAE S. nutans, and their structures were characterized using spectroscopic techniques as 1D and 2D NMR, and mass spectrometry. Vascular reactivity experiments were carried out in rat aorta. S. nutans-dependent vasodilation and phenylephrine-dependent contraction were measured in endothelium-intact and endothelium-denuded aortic rings of male rats.

Results: Seven pure compounds were isolate from HAE S. nutans, but two pure compounds showed significant vasodilation in rat aorta: 4-hydroxy-3-(3-methyl-2-butenyl)acetophenone (compound E) and 5-acetyl-6-hydroxy-2-isopropenyl-2,3-dihydrobenzofurane (compound G). Although HAE S. nutans induced vasodilation in absence of endothelium, the vasodilation in intact aorta, via NO, was higher. HAE S. nutans reduced calcium-dependent contraction in endothelium-intact, but not in endothelium-denuded aortic rings.

Conclusion: HAE S. nutans and its isolated compounds caused vasodilation in rat aorta in absence of endothelium, suggesting its vasodilator properties is endothelium-dependent (NO) and or independent, and may involve a modulation of the calcium channels. This result is of clinical interest as potential therapy control of blood pressure.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jep.2016.07.008DOI Listing
November 2016

Treatment of Rats with Apocynin Has Considerable Inhibitory Effects on Arylamine N-Acetyltransferase Activity in the Liver.

Sci Rep 2016 05 31;6:26906. Epub 2016 May 31.

Natural Products Institute, University of the West Indies, Mona, Kingston 7, Jamaica.

The effect of apocynin on the activity of arylamine N-acetyltransferases (NATs) in excised liver samples was examined using eighteen Sprague-Dawley rats. Three groups of six animals each were fed a normal diet alone or a treatment of 50 or 100 mg/kg/day of apocynin via gavages for eight (8) weeks. Chronic in vivo administration of apocynin led to significant (p < 0.001) reduction of in vitro liver NAT activity up to 93% as compared with untreated rats (18.80 ± 2.10 μmols p-anisidine/min/μg liver protein). In vitro exposure of untreated liver homogenates to apocynin led to a dose-dependent inhibition of NAT activity with IC50 = 0.69 ± 0.02 mM. In silico modelling of apocynin tautomers and radical species into human NAT crystal structures supported the hypothesis that thiol functionalities in NAT enzymes may be crucial in apocynin binding. The involvement of human NAT enzymes in different pathological conditions, such as cancer, has encouraged the research for selective NAT inhibitors in both humans and animal models with possible chemopreventive properties.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/srep26906DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4886258PMC
May 2016

Hypotensive and antihypertensive effects of a hydroalcoholic extract from Senecio nutans Sch. Bip. (Compositae) in mice: Chronotropic and negative inotropic effect, a nifedipine-like action.

J Ethnopharmacol 2016 Feb 25;179:367-74. Epub 2015 Dec 25.

Laboratorio de Química Biológica, Instituto Antofagasta (IA), Universidad de Antofagasta, Antofagasta, Chile.

Ethnopharmacological Relevance: Senecio nutans Sch. Bip. (Compositae) is an endemic plant of South America used in the management of acute mountain sickness in the Andean communities. Currently, the direct effects of hydroalcoholic extract from S. nutans on the cardiovascular system are unknown. The aim of this study was to determine the effects and mechanism of action of S. nutans on cardiovascular function in normotensive and Angiotensin II (1μg/mL) hypertension mice models.

Material And Methods: Blood pressure and ECG measurements were simultaneously carried out on the mice and rats. The isolated right atrium, papillary muscle of the left ventricle and isolated heart of rat were used to study the cardiac functions and mechanisms.

Results: S. nutans (40mg/Kg) induced a 30% and 12% significant (p<0.05) reduction of the mean arterial pressure (MAP) in normotensive and hypertensive mice respectively. This decrease was as a result of decrease in heart rate (HR) in normotensive (25%) and hypertensive model (31%). It also decreased the sinus rhythm in isolated right atrium of rat. Compared with Losartan, a known anti-hypertensive, S. nutans caused a dose-dependent negative inotropic effect (dP/dtmax) on Langendorff isolated heart system. While Losartan, decreased the MAP by 30% but had no effect on heart rate. The calcium blocker nifedipine had similar effects as S. nutans, decreasing the beat frequency of isolated right atrium and contractility of papillary muscle of the left ventricle of rat.

Conclusion: The results suggest an important clinical function in hypertension therapy, as S. nutans could decrease the blood pressure in hypertensive mice by decreasing the HR and contractility, leading to a reduction in myocardial oxygen demand.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jep.2015.12.048DOI Listing
February 2016

Erratum to: Synchronization in the Heart Rate and the Vasomotion in Rat Aorta: Effect of Arsenic Trioxide.

Cardiovasc Toxicol 2016 Jan;16(1):89

Cellular and Molecular Physiology Laboratory (CMPL), Division of Obstetrics and Gynecology, School of Medicine, Faculty of Medicine, Pontificia Universidad Católica de Chile, 8330024, Santiago, Chile.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s12012-015-9340-0DOI Listing
January 2016

Synchronization in the Heart Rate and the Vasomotion in Rat Aorta: Effect of Arsenic Trioxide.

Cardiovasc Toxicol 2016 Jan;16(1):79-88

Department of Basic Medical Sciences Physiology Section, Faculty of Medical Sciences, The University of the West Indies, Mona, Kingston 7, Jamaica, W.I.

Arsenic trioxide (As2O3) is used clinically in the management of acute promyelocytic leukemia, and the use of electrocardiogram (ECG) in this management is important as arsenic use may cause distortion of the electrical properties with its attendant sequel. We studied the effect of As2O3 on vasomotion in rat aortic rings using isometric tension recordings and ECG in anesthetized rats. The results showed that As2O3 (10(-5) M) significantly (p < 0.01) reduced the frequency of acetylcholine (10(-5) M ACh)- and KCl (10 mM)-induced vasomotion, and it also increased the relaxation time (R t) of vasomotion. This effect was restored by 10(-8) M sodium nitroprusside (nitric oxide donor). ACh-induced NO release in the aorta was blunted in the presence of As2O3. The corrected QT interval (QTc) of the ECG, and time dilation (T d) of the pulse wave in the tail artery of the anesthetized rat were significantly (p < 0.05) increased in the arsenic-treated group (50 ppb As) versus control. In conclusion, data suggest that arsenic-induced reduction in vasomotion frequency of the isolated aortic rings is associated with a decreased bioavailability of NO, an increase in QTc and a decrease in the frequency of the pulse wave generated by the cardiac cycle in anesthetized rats.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s12012-015-9312-4DOI Listing
January 2016

A comparative study of the effect of some nutritional medicinal plants effect on lead accumulation in the liver following different modes of administration.

Pharmacognosy Res 2014 Oct;6(4):306-11

Federal University of Technology, Owerri, Nigeria.

Context And Objectives: Lead (Pb) toxicity leads to cell damage in many organs of the body. Using different treatment interventions and modes of administration we comparatively examined the protective ability of some medicinal plants on liver Pb accumulation.

Materials And Methods: Rats were fed on either 7% w/w Zingiber officinale, 7% w/w Allium sativum, 10% w/w Lycopersicon esculentum, 5%, w/w Garcinia kola (all in rat chow), while Pb (100 ppm) was given in drinking water. The additives were administered together with (mode 1), a week after exposure to (mode 2) or a week before metal exposure to (mode 3) the metal for a period of 6 weeks. The metal accumulations in the liver were determined using atomic absorption spectrometry and compared using analysis of variance.

Results: Some additives significantly (P < 0.05) reduced, while others enhanced Pb accumulation. Mode 2 yielded the highest mean % protection and mode 3 the lowest, no significant interaction between modes of administration and time of measurement in their relationships to percentage protection, but there was statistically significant (P < 0.05) interaction between modes of administration and additive used in their relationships to percentage protection.

Conclusion: Protective effects of medicinal plants are varied and depend on the nature of lead exposure.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4103/0974-8490.138278DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4166819PMC
October 2014

Investigation of effects of time of measurement and modes of administration on cadmium accumulation in rat liver under some medicinal plants food supplemented diet.

Pharmacognosy Res 2014 Jul;6(3):240-5

Department of Biotechnology, Federal University of Technology, Owerri, Nigeria.

Context And Objectives: Cadmium (Cd) toxicity leads to cell and organ damage, we comparatively examined the protection ability of different medicinal plants on Cd liver accumulation following different treatment interventions and modes of administration.

Materials And Methods: Rats were fed either 7% w/w Zingiber officinale, 7% w/w Allium Sativum, 10% w/w Lycopersicon esculentum, 5%, w/w Garcinia kola (all in rat chow), while Cd (200 ppm) was given in drinking water. Additives were administered together with (mode 1), a week after (mode 2) or a week before metal exposure (mode 3) for a period of six weeks. Cd liver was determined using AAS and compared using analysis of variance (ANOVA).

Results: All additives significantly (P <0.5) reduced the accumulation of Cd in the liver. After adjusting for time and mode of administration, mean %protection for week 4 was significantly lower by 14.1% (P=0.02) from that for week 2 but the means did not differ with respect to additive used or mode of administration, no statistically significant interaction between modes of administration and either of additives used or time of administration in their respective relationships to percentage protection from Cd.

Conclusion: Additives significantly reduced Cd accumulation through a reduction in absorption and enhancement of metal excretion.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4103/0974-8490.132604DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4080505PMC
July 2014

Attenuated vascular responsiveness to K+ channel openers in diabetes mellitus: the differential role of reactive oxygen species.

Gen Physiol Biophys 2013 Dec 12;32(4):527-34. Epub 2013 Aug 12.

Department of Physiology, College of Medical Sciences, University of Calabar, Calabar, Nigeria.

The current study examined the responsiveness of blood vessels from diabetic rats to K+ channel openers and explored whether ROS might be involved in any changes. Responses were measured in aortic rings isolated from four weeks streptozotocin (65 mg/kg)-induced diabetic rats. Relaxation to levcromakalim (ATP-sensitive potassium channel KATP opener, 10(-9)-10(-5) mol/l) and (+/-)-naringenin (large conductance calcium-activated channel BKCa opener, 10(-8)-10(-3) mol/l) were recorded in phenylephrine (1 µmol/l) pre-contracted segments in the absence and presence of superoxide dismutase (SOD, 100 µmol/l) and apocynin (an antioxidant and inhibitor of NADPH oxidase, 100 µmol/l). Contractions to phenylephrine (10(-9)-10(-5) mol/l) and relaxation to acetylcholine (ACh, 10(-9)-10(-5) mol/l) were also recorded. Relaxation curves for levcromakalim, naringenin and ACh for the diabetic group were shifted to the right (p < 0.05) compared with the control. Contractions to phenylephrine were enhanced in the diabetic group (p < 0.01). SOD restored the ACh response but not those of K+ channel openers. On the other hand, apocynin restored the relaxation to naringenin but had no effect on both levcromakalim and ACh responses. The results suggest that both KATP and BKCa activities are attenuated in diabetes mellitus and that ROS appears to contribute only to the change in BKCa function.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4149/gpb_2013057DOI Listing
December 2013