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Akinboro A Mohamed KB Asmawi MZ Sulaiman SF Sofiman OA 《Journal of Zhejiang University. Science. B》2011,12(11):915-922
In this study, freeze-dried water extract from the leaves of Myristica fragrans (Houtt.) was tested for mutagenic and antimutagenic potentials using the Allium cepa assay. Freeze-dried water extract alone and its combination with cyclophosphamide (CP) (50 mg/kg) were separately dissolved
in tap water at 500, 1000, 2000, and 4000 mg/kg. Onions (A. cepa) were suspended in the solutions and controls for 48 h in the dark. Root tips were prepared for microscopic evaluation. 2,2-Diphenyl-1-picrylhydrazyl
(DPPH) free radicals’ scavenging power of the extract was tested using butylated hydroxyanisole (BHA) and butylated hydroxytoluene
(BHT) as standards. Water extract of Myristica fragrans scavenged free radicals better than BHA, but worse than BHT. The extract alone, as well as in combination with CP suppressed
cell division, and induced chromosomal aberrations that were insignificantly different from the negative control (P≤0.05). However, cytotoxic and mutagenic actions of CP were considerably suppressed. The observed effects on cell division
and chromosomes of A. cepa may be principally connected to the antioxidant properties of the extract. The obtained results suggest mitodepressive and
antimutagenic potentials of water extract of the leaves of M. fragrans as desirable properties of a promising anticancer agent. 相似文献
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A videotaped demonstration was compared with a conventional laboratory experiment in physiology for first‐year pharmacy students. The experiment was designed as an exercise in the use of the scientific method. The class was divided into a control group who performed the experiment for themselves, and an experimental group who were given the demonstration and spent most of the time analysing and interpreting the data using a semi‐programmed report sheet. After the practical session all students wrote an essay‐type report. The short‐ and long‐term gains resulting from practical work were assessed using objective pre‐ and post‐tests of cognitive performance. An answer review was given to half of each treatment group after the first post‐test. The short‐term gains were very moderate and were not significantly different for the treatment groups. The long‐term gains were significantly higher for the subgroups given the test answer review. The essay report did not reinforce the gains from the practical experience. Formal assessment of laboratory work did not stimulate motivation and interest in practical work. The findings imply that the role of practical work in some aspects of physiology might usefully be reviewed 相似文献
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