Publications by authors named "Ana Martiele Engelmann"

4 Publications

  • Page 1 of 1

In vitro and in vivo trypanocidal activity of a benzofuroxan derivative against Trypanosoma cruzi.

Exp Parasitol 2021 Jun 12:108125. Epub 2021 Jun 12.

Department of Microbiology and Parasitology, Federal University of Santa Maria, Santa Maria, RS, Brazil.

Chagas disease, caused by Trypanosoma cruzi, is a major public health problem and is described as one of the most neglected diseases worldwide. It affects about 6-7 million people. Currently, only two drugs are available for the treatment of this disease: nifurtimox and benznidazole. However, both drugs are highly toxic and have several side effects, which lead many patients to discontinue treatment. Moreover, these compounds show a significant curative efficacy only in the acute phase of the disease. Therefore, searching for new drugs is necessary. The objective of this study was to evaluate the in vitro and in vivo activity of a benzofuroxan derivative (EA2) against T. cruzi, and to evaluate the hematological and biochemical changes induced by its treatment in animals infected with T. cruzi. The results were then compared with those of healthy controls. In vitro testing was first performed with T. cruzi epimastigote forms. In this experiment, EA2 was diluted at three different concentrations (0.25, 0.50, and 1%). In vitro evaluation of the trypanocidal activity was performed 24, 48, and 72 h after incubation. In vivo assays were performed using three different doses (10, 5, and 2,5 mg/kg). Mice were divided into 10 groups (five animals/group), wherein four groups comprised non-infected animals (A, G, H, I) and six groups comprised infected animals (B, C, D E, F, J). Groups B and J represented the negative and positive controls, respectively. Groups G, H, and I were used to confirm that EA2 was not toxic to non-infected animals. Parasitemia was measured in infected animals and the hematological and biochemical profiles (urea, creatinine, albumin, aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase) were evaluated in all animals. EA2 demonstrated in vitro trypanocidal activity at all concentrations tested. Although it did not demonstrate a curative effect in vivo, EA2 was able to retard the onset of parasitemia, and significantly reduced the parasite count in groups D and E (treated with 5 and 2.5 mg/kg, respectively). EA2 did not induce changes in hematological and biochemical parameters in non-infected animals, demonstrating that it is not toxic. However, further assessments should aim to confirm the safety of EA2 since this was the first in vitro and in vivo study conducted with this molecule.
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http://dx.doi.org/10.1016/j.exppara.2021.108125DOI Listing
June 2021

Tucumã () extract: phytochemical characterization, acute and subacute oral toxicity studies in rats.

Drug Chem Toxicol 2020 Jun 14:1-12. Epub 2020 Jun 14.

Programa de Pós-Graduação em Farmacologia, Centro de Ciências da Saúde, Universidade Federal de Santa Maria, Santa Maria, Brasil.

Natural products are often used by the population to treat and/or prevent several disorders. Tucumã is an Amazonian fruit widely consumed by local population and no toxicity studies regarding its safety are available in the literature to date. Therefore, the phytochemical characterization, acute and repeated dose 28-day oral toxicities of crude extract of tucumã's pulp (CETP) in rats were evaluated. For the CETP preparation, tucumã pulp was crushed and placed into sealed amber glass jars containing absolute ethanol solution for extraction. CETP phytochemical analyses evidenced the presence of carotenoids, flavonoids, unsaturated and satured fatty acids, and triterpenes. In the acute toxicity, female rats from the test group were treated with CETP at single dose of 2000 mg/kg. For the repeated dose toxicity, CETP was administered to male and female rats at doses of 200, 400 and 600 mg/kg, for 28 days. Body weight was recorded during the experiment and blood, liver and kidney were collected for further analysis. No mortality or toxicity signs were observed during the studies. CETP was classified as safe (category 5, OECD guide), in acute toxicity. In repeated dose study was observed alterations in some biochemical parameters, as well as in oxidative damage and enzymatic activity. Histopathological findings showed renal damage in male rats at higher dose. The data obtained suggest that CETP did not induced toxicity after exposure to a single or repeated doses in female rats. However, in males may be considered safe when given repeatedly in low doses.
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http://dx.doi.org/10.1080/01480545.2020.1777151DOI Listing
June 2020

Hydroalcoholic extract of leaf of Arachis hypogaea L. (Fabaceae) did not induce toxic effects in the repeated-dose toxicity study in rats.

Regul Toxicol Pharmacol 2020 Aug 13;115:104683. Epub 2020 May 13.

Graduate Program in Pharmacology, Federal University of Santa Maria, 97105-900, Santa Maria, RS, Brazil. Electronic address:

Arachis hypogaea L. (peanut) leaf is traditionally used for the treatment of insomnia in Asia. However, studies describing the safety and toxicity profile for this plant preparation are limited. Thus, the goal of this study was to investigate the toxicity of peanut leaf hydroalcoholic extract (PLHE) repeated treatment. The extract was administered orally (100, 300 or 1000 mg/kg) in male and female Wistar rats for 28 days (OECD guideline 407). PLHE treatment did not cause mortality or weight variation in the animals. Also, there was no alteration on locomotor activity (open field test), motor coordination (rotarod test), or anxiety behaviour (elevated plus-maze test). Male rats had a reduction in relative liver weight (100 mg/kg) and an increase in total kidney weight (1000 mg/kg), but there was no change in biochemical and haematological parameters after PLHE treatment. Free extracellular double-stranded DNA (dsDNA) levels was also evaluated, but PLHE treatment did not increase this parameter in rat organs. Also, the dose of 1000 mg/kg of PLHE significantly increased the total thiols in the liver of females compared with the control animals. Thus, PLHE did not induce toxicity after repeated exposure for 28 days in rats.
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http://dx.doi.org/10.1016/j.yrtph.2020.104683DOI Listing
August 2020

Peanut leaf extract has antioxidant and anti-inflammatory activity but no acute toxic effects.

Regul Toxicol Pharmacol 2019 Oct 18;107:104407. Epub 2019 Jun 18.

Graduate Program in Pharmacology, Federal University of Santa Maria, 97105-900, Santa Maria, RS, Brazil. Electronic address:

Arachis hypogaea L. (peanut) leaves have been popularly used for the treatment of insomnia and inflammation, but no toxicological study has been performed for this plant preparation. This study aimed to examine the phytochemical composition of peanut leaf hydroalcoholic extract (PLHE) and describe its potential toxic effects and antioxidant and anti-inflammatory properties. The qualitative chemical analysis of PLHE by UHPLC-ESI-HRMS allowed the identification of eight metabolites types (totaling 29 compounds). The 1,1-diphenyl-2-picryl-hydrazyl (DPPH) assay revealed that PLHE had strong antioxidant effects; it also exhibited nitric oxide (NO)-scavenging capacity. Human peripheral blood mononuclear cells (PBMCs) exposed to PLHE showed no reduced cell viability or increased free double-stranded DNA, NO, or reactive species production. PLHE reversed the cytotoxicity, pro-inflammatory (release of interleukin-1β), and pro-oxidant effects of HO on human PBMCs. Acute PLHE toxicity analysis was performed in vivo using the Organization for Economic Co-operation and Development (OECD) 423 guidelines. PLHE single injection (2000 mg/kg, intragastric) did not cause mortality or morbidity or induce changes in hematological or biochemical parameters after 14 days of administration. Thus, PLHE could be a source of bioactive compounds and possesses antioxidant and anti-inflammatory properties without elicitin cytotoxicity or genotoxicity in human PBMCs or acute toxicity in rats.
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http://dx.doi.org/10.1016/j.yrtph.2019.104407DOI Listing
October 2019
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