Publications by authors named "Hui Meng Er"

20 Publications

  • Page 1 of 1

Development of and First Experiences with a Framework (EASI) for Options and Implementation Opportunities for Online Clinical and Communication Skills Learning.

J Med Educ Curric Dev 2020 Jan-Dec;7:2382120520970894. Epub 2020 Nov 19.

Teaching and Learning, International Medical University, Kuala Lumpur, Malaysia.

A preparatory framework called EASI (Evaluate, Align, Student-centred, Implement and Improve) was developed with the aim of creating awareness about interim options and implementation opportunities for online Clinical and Communication Skills (CCS) learning. The framework, when applied requires faculty to evaluate current resources, align sessions to learning outcomes with student-centred approaches and to continuously improve based on implementation experiences. Using the framework, we were able to generate various types of online CCS learning sessions for implementation in a short period of time due to the recent Covid-19 pandemic. Importantly we learnt a few lessons post-implementation from both students and faculty perspective that will be used for planning and delivery of future sessions. In summary, the framework was useful for creating or redesigning CCS sessions which were disrupted during the pandemic, however post-implementation experience suggests the framework can also be used for future solutions in online CCS learning as healthcare systems and delivery are increasingly decentralised and widely distributed.
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http://dx.doi.org/10.1177/2382120520970894DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7682242PMC
November 2020

Quality assurance in education: perception of undergraduate health professions students in a Malaysian university.

Korean J Med Educ 2020 Sep 21;32(3):185-195. Epub 2020 Jul 21.

Quality Improvement Unit, International Medical University, Kuala Lumpur, Malaysia.

Purpose: Direct student involvement in quality processes in education has been suggested to encourage shared responsibilities among faculty and students. The objectives of this study were to explore undergraduate health professions students' understanding of quality assurance (QA) in education, and identify the challenges and enablers for student involvement in an Asian context.

Methods: Twenty semi-structured interviews were conducted among medical, dentistry, and pharmacy students in a Malaysian University. The interviews were audio-recorded, transcribed verbatim, and thematically analyzed to understand the students' perspectives of QA in education.

Results: The participants recognized the importance of QA towards ensuring the quality of their training, which will consequently impact their work readiness, employability, and quality of healthcare services. Academic governance, curriculum structure, content and delivery, faculty and student quality, teaching facilities, and learning resources were indicated as the QA areas. The challenges for students' involvement included students' attitude, maturity, and cultural barrier. To enhance their buy-in, clear objectives and impact, efficient QA mechanism, and recognition of students' contribution had been suggested.

Conclusion: The findings of this study support student-faculty partnership in QA processes and decision making.
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http://dx.doi.org/10.3946/kjme.2020.166DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7481045PMC
September 2020

Turning around a medical education conference: Ottawa 2020 in the time of COVID-19.

Med Educ 2020 08 26;54(8):760-761. Epub 2020 May 26.

An International Association for Medical Education, Dundee, UK.

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http://dx.doi.org/10.1111/medu.14197DOI Listing
August 2020

Twelve tips for institutional approach to outcome-based education in health professions programmes.

Med Teach 2019 Sep 14:1-6. Epub 2019 Sep 14.

Faculty of Medicine and Health, International Medical University , Kuala Lumpur , Malaysia.

Outcome-based education (OBE) has brought along a significant development in health professions education in the past decade. The shift from a process-driven to product-driven model of education is valuable for ensuring graduate quality and facilitating global movement of healthcare workers. Such a model can align the expectations of key stakeholders in an era of rapid knowledge expansion and technological advancement. Nevertheless, the experienced benefits of OBE depend on the effectiveness of its implementation. This article therefore provides practical tips and strategies for implementing OBE in order to maximize its potential.
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http://dx.doi.org/10.1080/0142159X.2019.1659942DOI Listing
September 2019

Pharmacy Students' Perceptions of Reflective Portfolios and their Effect on Students' Deep Information-Processing Skills.

Am J Pharm Educ 2019 08;83(6):6851

International Medical University, Kuala Lumpur, Malaysia.

To evaluate pharmacy students' perceptions of the educational value of reflective portfolio and to gain an understanding of the factors that might influence these perceptions. Bachelor of Pharmacy (BPharm) students' perceptions of using reflective portfolios were evaluated by administering the same questionnaire at the beginning of years 2, 3 and 4 of the curriculum. Statistical analysis was carried out to determine the differences among the perception scores of different academic years. Semi-structured interviews were completed with fourth-year students to further explore their experiences with the reflective portfolio. Students' deep information processing (DIP) skills were compared with those of students from another pharmacy cohort whose curriculum did not include a reflective portfolio. The students' perceptions of the reflective portfolio improved significantly as they progressed from year 2 to year 4 of the curriculum. The factors that contributed to a positive experience were a clear understanding of objectives and guidelines for the reflective portfolio, useful mentor feedback, a positive learning attitude and motivation, and having a user-friendly technology platform for submission of the portfolio. The students' DIP skills after completing the reflective portfolio were higher than those of students who did not have a reflective portfolio assignment in their curriculum. Pharmacy students' appreciation of the educational value of a reflective portfolio increased as they progressed to their final year, and their DIP skills improved. These findings support the use of a reflective portfolio as a learning tool for BPharm students' personal and professional development.
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http://dx.doi.org/10.5688/ajpe6851DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6718510PMC
August 2019

Student evaluation of the learning environment in an undergraduate pharmacy programme: Lessons for educators.

Med Teach 2019 Sep 6:1-8. Epub 2019 Sep 6.

School of Pharmacy, International Medical University , Kuala Lumpur , Malaysia.

Student evaluation of the learning environment is important to enhance learning experiences. Programs such as Pharmacy use feedback from the evaluation to identify teaching-learning issues and use it to improve the quality of the learning experiences. The article aims to explore the general observations from the evaluation; to identify how the feedback is used to improve the learning environment and to identify lessons for educators in managing and using the feedback. A cross-sectional data analysis of Pharmacy students' learning environment from 2011-2015 based on data from module, faculty, IMU-REEM and Student Barometer Survey was applied. Feedback obtained from the data was triangulated to establish commonalities/differences of the issues. Based on the analysis, issues affecting Pharmacy student learning experiences were identified. The identified issues included teaching by subject matter experts, pedagogical delivery and physical learning environment. Seven lessons were presented for educators to assess the practicality of the feedback. The feedback serves as a means to improve the Pharmacy program. Nonetheless, the challenges lie between the ideal and realistic expectations of students in optimizing the learning experiences. Lessons acquired from the evaluation of the learning environment are essential for educators in managing and using the information.
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http://dx.doi.org/10.1080/0142159X.2019.1654089DOI Listing
September 2019

Medical students' orientation toward lifelong learning in an outcome-based curriculum and the lessons learnt.

Med Teach 2019 Aug 13:1-6. Epub 2019 Aug 13.

a Faculty of Medicine and Health, International Medical University , Kuala Lumpur , Malaysia.

Lifelong learning (LL) is an important outcome of medical training. The objective of this study is to measure the orientation of medical students toward LL and to determine the types of self-directed learning (SDL) activities that contribute toward LL skills. The Jefferson Scale of Physician Lifelong Learning for medical student (JeffSPLL-MS) questionnaire was used. Factor analysis was performed, Cronbach's alpha and effect size were calculated. The types of learning activities that contribute to LL skills were identified. Three-factor structure emerged from the factor analysis and were identified as learning beliefs and motivation, skills in seeking information and attention to learning opportunities. A significant increase ( < .05; ES = 0.27) in orientation toward LL with academic progression was observed. Clinical students improved significantly in the domains of 'skills in seeking information' ( < .001; ES = 0.48) and 'attention to learning opportunities' ( < .001; ES = 0.55). Problem-based learning, flipped classroom, guided reading, projects and experiential learning activities are perceived to be effective for promoting LL. Medical students' LL skills develop progressively from preclinical to clinical years. Self-directed learning activities are perceived to be effective in promoting LL skills.
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http://dx.doi.org/10.1080/0142159X.2019.1646894DOI Listing
August 2019

Preparation and Optimization OF Palm-Based Lipid Nanoparticles Loaded with Griseofulvin.

Iran J Pharm Res 2017 ;16(2):451-461

Department of Pathology, School of Medicine, International Medical University, No. 126, Jalan Perkasa 19, Bukit Jalil, 57000 Kuala Lumpur, Malaysia.

Palm-based lipid nanoparticle formulation loaded with griseofulvin was prepared by solvent-free hot homogenization method. The griseofulvin loaded lipid nanoparticles were prepared via stages of optimisation, by altering the high pressure homogenisation (HPH) parameters, screening on palm-based lipids and Tween series surfactants and selection of lipid to surfactant ratios. A HPLC method has been validated for the drug loading capacity study. The optimum HPH parameter was determined to be 1500 bar with 5 cycles and among the palm-based lipid materials; Lipid C (triglycerides) was selected for the preparation of lipid nanoparticles. Tween 80 was chosen from the Tween series surfactants for its highest saturated solubility of griseofulvin at 53.1 ± 2.16 µg/mL. The optimum formulation of the griseofulvin loaded lipid nanoparticles demonstrated nano-range of particle size (179.8 nm) with intermediate distribution index (PDI) of 0.306, zeta potential of -27.9 mV and drug loading of 0.77%. The formulation was stable upon storage for 1 month at room temperature (25 C) and 45 C with consistent drug loading capacity.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5603854PMC
January 2017

Tumor regression and modulation of gene expression via tumor-targeted tocotrienol niosomes.

Nanomedicine (Lond) 2017 Oct 20;12(20):2487-2502. Epub 2017 Sep 20.

Product Development & Advisory Services Division, Malaysian Palm Oil Board, No 6, Persiaran Institusi, Bandar Baru Bangi, 43000 Kajang, Selangor Darul Ehsan, Malaysia.

Aim: To develop 6-O-palmitoyl-ascorbic acid-based niosomes targeted to transferrin receptor for intravenous administration of tocotrienols (T3) in breast cancer.

Materials & Methods: Niosomes were prepared using film hydration and ultrasonication methods. Transferrin was coupled to the surface of niosomes via chemical linker. Nanovesicles were characterized for size, zeta potential, morphology, stability and biological efficacy.

Results: When evaluated in MDA-MB-231 cells, entrapment of T3 in niosomes caused 1.5-fold reduction in IC value compared with nonformulated T3. In vivo, the average tumor volume of mice treated with tumor-targeted niosomes was 12-fold lower than that of untreated group, accompanied by marked downregulation of three genes involved in metastasis.

Conclusion: Findings suggested that tumor-targeted niosomes served as promising delivery system for T3 in cancer therapy.
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http://dx.doi.org/10.2217/nnm-2017-0182DOI Listing
October 2017

Study on the impact of open and closed book formative examinations on pharmacy students' performance, perception, and learning approach.

Curr Pharm Teach Learn 2016 May - Jun;8(3):364-374. Epub 2016 Mar 21.

School of Pharmacy, International Medical University, Bukit Jalil, 57000 Kuala Lumpur, Malaysia.

Objectives: To study the impact of open and closed book formative examinations on pharmacy students' learning approach and also to assess their performance and perception about open book (OB) and closed book (CB) systems of examination.

Methods: A crossover study was conducted among Year 1 and Year 2 pharmacy students. Students were invited to participate voluntarily for one OB and one CB online formative test in a chemistry module in each year. Evaluation of their learning approach and perception of the OB and CB systems of examination was conducted using Deep Information Processing (DIP) questionnaire and Student Perception questionnaire respectively. The mean performance scores of OB and CB examinations were compared.

Results: Analysis of DIP scores showed that there was no significant difference (p > 0.05) in the learning approach adopted for the two different examination systems. However, the mean score obtained in the OB examination was significantly higher (p < 0.01) than those obtained in the CB examination. Preference was given by a majority of students for the OB examination, possibly because it was associated with lower anxiety levels, less requirement of memorization, and more problem solving.

Conclusion: There is no difference in deep learning approach of students, whether the format is of the OB or CB type examinations. However, the performance of students was significantly better in OB examination than CB. Hence, using OB examination along with CB examination will be useful for student learning and help them adapt to growing and changing knowledge in pharmacy education and practice.
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http://dx.doi.org/10.1016/j.cptl.2016.02.017DOI Listing
March 2016

In vitro anti-inflammatory activity of fractionated Euphorbia hirta aqueous extract on rabbit synovial fibroblasts.

Biomed J 2015 Jul-Aug;38(4):301-6

School of Pharmacy, International Medical University, Kuala Lumpur, Malaysia.

Background: Euphorbia hirta has been reported to possess anti-inflammatory activity. This study was carried out to determine the prostaglandin E 2 (PGE 2 ) inhibition activity of the fractions of the E. hirta aqueous extract on rabbit synovial fibroblast cells (HIG-82).

Methods: E. hirta aqueous extract was fractionated into five fractions (fractions A, B, C, D, and E) by reversed phase flash chromatography. Rabbit synovial fibroblast cells (HIG-82) were activated with phorbol myristate acetate and treated with the fractions. The amount of PGE 2 released into the medium was measured by enzyme-linked immunosorbent assay.

Results: Fraction A (0.1, 1, and 10 μg/ml) had the greatest PGE 2 inhibitory effect among the five fractions, and showed a greater extent of PGE 2 inhibition compared to the aqueous extract. In contrast, Fraction E had the greatest stimulatory effect on PGE 2 release.

Conclusions: Fraction A of the aqueous extract inhibited the production of PGE 2 from activated HIG-82 cells to a greater extent than the crude aqueous extract. Bioactive compounds with anti-inflammatory activity are likely to be concentrated in Fraction A of E. hirta aqueous extract.
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http://dx.doi.org/10.4103/2319-4170.151031DOI Listing
December 2016

In vitro determination of the effect of Andrographis paniculata extracts and andrographolide on human hepatic cytochrome P450 activities.

J Nat Med 2011 Jul 3;65(3-4):440-7. Epub 2011 Mar 3.

School of Pharmacy and Health Sciences, International Medical University, 57000, Kuala Lumpur, Malaysia.

We investigated the effects of Andrographis paniculata (AP) extracts and andrographolide on the catalytic activity of three human cDNA-expressed cytochrome P450 enzymes: CYP2C9, CYP2D6 and CYP3A4. In vitro probe-based high performance liquid chromatography assays were developed to determine CYP2C9-dependent tolbutamide methylhydroxylation, CYP2D6-dependent dextromethorphan O-demethylation and CYP3A4-dependent testosterone 6β-hydroxylation activities in the presence and absence of AP extracts and andrographolide. Our results indicate that AP ethanol and methanol extracts inhibited CYP activities more potently than aqueous and hexane extracts across the three isoforms. Potent inhibitory effects were observed on CYP3A4 and CYP2C9 activities (K (i) values below 20 μg/ml). Andrographolide was found to exclusively but weakly inhibit CYP3A4 activity. In conclusion, data presented in this study suggest that AP extracts have the potential to inhibit CYP isoforms in vitro. There was, however, variation in the potency of inhibition depending on the extracts and the isoforms investigated.
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http://dx.doi.org/10.1007/s11418-011-0516-zDOI Listing
July 2011

In vitro effects of active constituents and extracts of Orthosiphon stamineus on the activities of three major human cDNA-expressed cytochrome P450 enzymes.

Chem Biol Interact 2011 Mar 27;190(1):1-8. Epub 2011 Jan 27.

School of Pharmacy and Health Sciences, International Medical University, 126, Jalan 19/155B, Bukit Jalil, 57000 Kuala Lumpur, Malaysia.

Orthosiphon stamineus (OS) has been traditionally used to treat diabetes, kidney and urinary disorders, high blood pressure and bone or muscular pain. To assess the possibility of drug-herb interaction via interference of metabolism, effects of four OS extracts of different polarity and three active constituents (sinensetin, eupatorin and rosmarinic acid) on major human cDNA-expressed cytochrome P450 (CYP) enzymes were investigated. Three substrate-probe based high-performance liquid chromatography (HPLC) assays were established to serve as activity markers for CYP2C9, CYP2D6 and CYP3A4. Our results indicate that OS extracts and constituents exhibited differential modulatory effects on different CYPs. While none of the OS components showed significant inhibition on CYP2C9, eupatorin strongly and uncompetitively inhibited CYP2D6 activity with a K(i) value of 10.2μM. CYP3A4 appeared to be the most susceptible enzyme to OS inhibitory effects. It was moderately inhibited by OS dichloromethane and petroleum ether extract with mixed-type and noncompetitive inhibitions (K(i)=93.7 and 44.9μg/mL), respectively. Correlation study indicated that the inhibition was accounted for by the presence of eupatorin in the extracts. When IC(50) values of these extracts were expressed in volume per dose unit to reflect inhibitory effect at recommended human doses from commercially available products, moderate inhibition was also observed. In addition, CYP3A4 was strongly and noncompetitively inhibited by eupatorin alone, with a K(i) value of 9.3μM. These findings suggest that co-administration of OS products, especially those with high eupatorin content, with conventional drugs may have the potential to cause drug-herb interactions involving inhibition of major CYP enzymes.
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http://dx.doi.org/10.1016/j.cbi.2011.01.022DOI Listing
March 2011

In vitro modulatory effects of Andrographis paniculata, Centella asiatica and Orthosiphon stamineus on cytochrome P450 2C19 (CYP2C19).

J Ethnopharmacol 2011 Jan 18;133(2):881-7. Epub 2010 Nov 18.

School of Pharmacy and Health Sciences, International Medical University, 126 Jalan 19/155B, Bukit Jalil, 57000 Kuala Lumpur, Malaysia.

Ethno Pharmacological Relevance: Andrographis paniculata (AP), Centella asiatica (CA) and Orthosiphon stamineus (OS) are three popular herbs traditionally used worldwide. AP is known for the treatment of infections and diabetes and CA is good for wound healing and healthy skin while OS is usually consumed as tea to treat kidney and urinary disorders. Interaction of these herbs with human cytochrome P450 2C19 (CYP2C19), a major hepatic CYP isoform involved in metabolism of many clinical drugs has not been investigated to date.

Aim Of The Study: In this study, the modulatory effects of various extracts and major active constituents of AP, CA and OS on CYP2C19 activities were evaluated.

Materials And Methods: S-mephenytoin, the CYP2C19 substrate probe, was incubated in the presence or absence of AP, CA and OS components. The changes in the rate of metabolite (hydroxymephenytoin) formation were subsequently determined by a high-performance liquid chromatography (HPLC)-based enzyme assay to characterize the modulatory effects.

Results: Among the herbal extracts studied, AP ethanol extract and CA dichloromethane extract exhibited mixed type inhibition towards CYP2C19 with K(i) values of 67.1 and 16.4 μg/ml respectively; CA ethanol extract and OS petroleum ether extract competitively inhibited CYP2C19 activity (K(i)=39.6 and 41.5 μg/ml respectively). Eupatorin (a major active constituent of OS) was found to significantly inhibit CYP2C19 by mixed type inhibition (K(i)=7.1 μg/ml or 20.6 μM).

Conclusions: It was observed that AP, CA and OS inhibited CYP2C19 activity with varying potency. While weak inhibitory effect was observed with AP, moderate to strong inhibition was observed with CA dichloromethane extract and eupatorin, the major OS constituent. Therefore care should be taken when these CA and OS components are co-administered with CYP2C19 substrates (such as omeprazole, proguanil, barbiturates, citalopram, and diazepam).
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http://dx.doi.org/10.1016/j.jep.2010.11.026DOI Listing
January 2011

In vitro modulatory effects on three major human cytochrome P450 enzymes by multiple active constituents and extracts of Centella asiatica.

J Ethnopharmacol 2010 Jul 8;130(2):275-83. Epub 2010 May 8.

School of Pharmacy and Health Sciences, International Medical University, Bukit Jalil, Kuala Lumpur, Malaysia.

Ethnopharmacological Relevance: Centella asiatica (CA) has been widely cultivated as a vegetable or spice in China, Southeast Asia, India, Sri Lanka, Africa, and Oceanic countries and traditionally used for wound healing and maintaining normal blood pressure.

Aim Of The Study: The present study was carried out to examine the potential modulatory effects of three commercially available active components (asiaticoside, asiatic acid and madecassic acid) and four extracts (aqueous, ethanol, dichloromethane and hexane) of CA on three major cDNA-expressed human cytochrome P450 (CYP) isoforms.

Materials And Methods: High-performance liquid chromatography (HPLC)-based enzyme assays, namely tolbutamide 4-methyhydroxylase, dextromethorphan O-demethylase and testosterone 6beta-hydroxylase assays were developed to probe activities of CYP2C9, CYP2D6 and CYP3A4, respectively. Probe substrates were incubated with or without each active component and extract for each isoform, followed by examination of the kinetics parameters, IC(50) and K(i), to characterize modulatory effects.

Results: CYP2C9 was more susceptible to inhibitory effects by CA extracts compared to CYP2D6 and CYP3A4. Moderate degree of inhibition was observed in ethanol (K(i)=39.1 microg/ml) and dichloromethane (K(i)=26.6 microg/ml) extracts implying potential risk of interaction when CYP2C9 substrates are consumed with CA products. The two extracts however showed negligible inhibition towards CYP2D6 and CYP3A4 (IC(50)'s of 123.3 microg/ml and above). Similarly CA aqueous and hexane extracts did not significantly inhibit all three isoforms investigated (IC(50)'s of 117.9 microg/ml and above). Among the active constituents investigated, asiatic acid and madecassic acid appeared to selectively inhibit CYP2C9 and CYP2D6 more than CYP3A4. Of particular interest is the potent inhibitory effect of asiatic acid on CYP2C9 (K(i)=9.1 microg/ml). This signifies potential risk of interaction when substrates for this isoform are taken together with CA products with high asiatic acid content. Inhibitions of asiatic acid with the other isoforms and that of madecassic acid with all isoforms were only moderate (K(i)'s ranged from 17.2 to 84.4 microg/ml). On the other hand, the IC(50) values for asiaticoside were high (1070.2 microg/ml or above) for all three isoforms, indicating negligible or low potential of this compound to modulate CYP enzymatic activity.

Conclusion: Centella asiatica extracts and active constituents inhibited CYP2C9, CYP2D6 and CYP3A4 activities with varying potency with CYP2C9 being the most susceptible isoform to inhibition. Significant inhibition was observed for asiatic acid and CA ethanol and dichloromethane extracts, implying involvement of semipolar constituents from CA in the effect. This study suggested that CA could cause drug-herb interactions through CYP2C9 inhibition.
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http://dx.doi.org/10.1016/j.jep.2010.05.002DOI Listing
July 2010

Mutagenic and antimutagenic activities of aqueous and methanol extracts of Euphorbia hirta.

J Ethnopharmacol 2009 Dec 22;126(3):406-14. Epub 2009 Sep 22.

School of Pharmacy and Health Sciences, International Medical University, No. 126, Jalan 19/155B, 57000 Bukit Jalil, Kuala Lumpur, Malaysia.

Euphorbia hirta (E. hirta) is a weed commonly found in tropical countries and has been used traditionally for asthma, bronchitis and conjunctivitis. However, one of the constituents in this plant, quercetin, was previously reported to be mutagenic. This work aimed to determine the level of quercetin in the aqueous and methanol plant extracts and to investigate the mutagenic effects of quercetin and the extracts in the Ames test utilising the mutant Salmonella typhimurium TA98 and TA100 strains. The antimutagenic activity of Euphorbia hirta aqueous and methanol extracts was also studied in Salmonella typhimurium TA98. HPLC analyses showed that quercetin and rutin, a glycosidic form of quercetin, were present in the acid-hydrolysed methanol extract and non-hydrolysed methanol extract respectively. The quercetin concentration was negligible in both non-hydrolysed and acid-hydrolysed aqueous extracts. The total phenolic contents in Euphorbia hirta were determined to be 268 and 93 mg gallic acid equivalent (GAE) per gram of aqueous and methanol extracts, respectively. Quercetin (25 microg/mL) was found to be strongly mutagenic in Salmonella typhimurium TA98 in the absence and presence of S-9 metabolic activation. However, both the aqueous and methanol extracts did not demonstrate any mutagenic properties when tested with Salmonella typhimurium TA98 and TA100 strains at concentrations up to 100 microg/mL in the absence and presence of S-9 metabolic activation. In the absence of S-9 metabolic activation, both the extracts were unable to inhibit the mutagenicity of the known mutagen, 2-nitrofluorene, in Salmonella typhimurium TA98. On the other hand, the aqueous extracts at 100 microg/mL and methanol extracts at 10 and 100 microg/mL exhibited strong antimutagenic activity against the mutagenicity of 2-aminoanthracene, a known mutagen, in the presence of S-9 metabolic activating enzymes. The results indicated that these extracts could modulate the xenobiotic metabolising enzymes in the liver at the higher concentrations.
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http://dx.doi.org/10.1016/j.jep.2009.09.025DOI Listing
December 2009

The effect of water extracts of Euphorbia hirta on cartilage degeneration in arthritic rats.

Malays J Pathol 2008 Dec;30(2):95-102

Human Biology Section, International Medical University, Kuala Lumpur, Malaysia.

The effect of water extracts of Euphorbia hirta on the histological features and expressions of matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) in the rat articular cartilage was investigated. Arthritis was induced in rats using Freund's Complete Adjuvant containing heat-killed M. tuberculosis, and treated with water extracts of E. hirta. Paraffin tissue sections of the arthritic joints were evaluated. The extent of cartilage degeneration was found to be greatest in rats treated with the highest dosage of E. hirta, followed by rats in the untreated group. Rats treated with the intermediary and low dosages of Euphorbia hirta showed improved histology. MMP-13 levels were found to be decreased with decreasing dosages of E. hirta. TIMP-1 levels were found to increase with decreasing dosages of E. hirta. MMP-3 levels fluctuated without any appreciable pattern. Low dosages of E. hirta seem to be beneficial in reducing cartilage degeneration in cases of arthritis.
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December 2008

Enantioselectivity and stereoselectivity in the reactions of the enantiomers of the platinum complex [PtCl2(ahaz)] (ahaz=3(R)- or 3(S)-aminohexahydroazepine) with DNA.

J Inorg Biochem 2009 Feb 10;103(2):168-73. Epub 2008 Oct 10.

School of Chemistry, The University of Sydney, NSW 2006, Australia.

The platinum-DNA adduct profile formed by the R- and S-enantiomers of [PtCl(2)(ahaz)] (ahaz=3(R)-aminohexahydroazepine or 3(S)-aminohexahydroazepine) on reaction with salmon sperm DNA were characterised using HPLC and GFAAS (graphite furnace atomic absorption spectrometry) analyses. At a platinum to nucleotide ratio (R(t)) equalling 0.05, the R-enantiomer forms a substantially larger amount (approximately 60%) of monofunctional adducts than the S-enantiomer (less than 35%). Fewer intrastrand GpG adducts are formed by the R-enantiomer (approximately 21%) than the S-enantiomer (approximately 37%). For both enantiomers, two isomeric GpG adducts, corresponding to the different orientations of the primary amine of ahaz ligand with respect to the O6 atom of the 5' guanine, were observed in the ratios of 1:1.3 and 1:4.3 for the R- and S-enantiomers, respectively. The reasons for this enantioselectivity and stereoselectivity are discussed.
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http://dx.doi.org/10.1016/j.jinorgbio.2008.09.016DOI Listing
February 2009

Anti-proliferative and mutagenic activities of aqueous and methanol extracts of leaves from Pereskia bleo (Kunth) DC (Cactaceae).

J Ethnopharmacol 2007 Sep 14;113(3):448-56. Epub 2007 Jul 14.

Faculty of Medicine, International Medical University, No. 126 Jalan 19/155B, Bujit Jalil, 57000 Kuala Lumpur, Malaysia.

The anti-proliferative effects of the aqueous and methanol extracts of leaves of Pereskia bleo (Kunth) DC (Cactaceae) against a mouse mammary cancer cell line (4T1) and a normal mouse fibroblast cell line (NIH/3T3) were evaluated under an optimal (in culture medium containing 10% foetal bovine serum (FBS)) and a sub-optimal (in culture medium containing 0.5% FBS) conditions. Under the optimal condition, the aqueous extract showed a significant (p<0.05) anti-proliferative effect at 200 microg/mL and 300 microg/mL in 4T1 cells and 300 microg/mL in NIH/3T3 cells, whereas the methanol extract did not show any notable anti-proliferative effect in these cell lines, at any of the concentrations tested. Under the sub-optimal condition, the aqueous extract showed a significant (p<0.05) anti-proliferative effect at 200 microg/mL and 300 microg/mL in NIH/3T3 cells, whilst the methanol extract showed a significant (p<0.05) anti-proliferative effect at 200 microg/mL and 300 microg/mL in both cell lines. An upward trend of apoptosis was observed in both 4T1 and NIH/3T3 cells treated with increasing concentrations of the aqueous extract. The level of apoptosis observed at all the concentrations of the aqueous extract tested was consistently higher than necrosis. There was a significant (p<0.05) increase in the level of necrosis observed in the 4T1 cells treated with 300 microg/mL of the methanol extract. Generally, the level of necrosis was noted to be higher than that of apoptosis in the methanol extract-treated cells. The mutagenicity assay performed showed that in the absence of S-9 liver metabolic activation, the extract was not mutagenic up to the concentration of 165 microg/mL . However, in the presence of S-9 liver metabolic activation, the aqueous extract was mutagenic at all the concentrations tested. This study shows that both the aqueous and methanol extracts of the leaves from Pereskia bleo (Kunth) DC (Cactaceae) do not have appreciable anti-proliferative effect on the 4T1 and NIH/3T3 cells as the EC(50) values obtained are greater than 50 microg/mL when tested under optimal culture condition. Moreover, the aqueous extract may form mutagenic compound(s) upon the metabolisation by liver enzymes.
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http://dx.doi.org/10.1016/j.jep.2007.06.026DOI Listing
September 2007