Bibliothèque de L'IMIST/CNRST

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Université Abdelmalek Essaadi

It is still true today that prevention is more important than treatment. For its part, chemoprevention strategies have earned serious consideration as a potential means of controlling the incidence of cancer. Edible plants, since immemorial times, have been used in virtually every culture throughout the world as a source of folk medicine. Currently, modulating factors from plants have been widely studied with respect to their abilitiy to prevent or minimize deleterious effects produced by an increasing number of mutagenic and carcinogenic environmental agents. In this fact, it is an essential task to identify plants that can present the capacity to inhibit mutagenesis and in many cases carcinogenesis. Another equally essential task is the evaluation of the genotoxic and mutagenic activitity of the edible plants uses commonly for medicinal proposes or as spices. Even if it is a widely held belief that herbal preparations are "natural" and are therefore intrinsically harmless. However, many plant secondary products are highly toxic and many others can be potentially mutagenic and/or carcinogenic. Using the Somatic Mutation and Recombination Test (SMART) in somatic cells of Drosophila melanogaster, the mutagenic and antimutagenic activity of black seeds (Nigella sativa), liquorice (Glycyrrhiza glabra), organo (Origanum vulgare), nutmeg (Myristica fragrance), rosemary (Rosmarinus officinalis) lemon verbena (Verbena triphylla) fenugreek seeds (Trigonella foenum-graecum) laurel (Laurus nobilis), african rue (Piganum harmala) and garlic (Allium sativum) was evaluated. The SMART assay was used in both version based on a eye or wing marker. In both cases, loss of heterozygosity leads to uncovering and expression of the recessive marker gene(s) in the larval imaginal disc cells. The wings and eyes of the emerging adults are analyzed for the occurrence of different types of mutant spots. Urethane_URE and Methylmethane-sulphonate_MMS were used as positive mutagens in our stydy. Urethane is a promutagenic whereas MMS is a direct alkylating agent. For the evaluation of the mutagenic and antimutagenic effects detected, the frequencies of spots of a treated series are compared to its concurent negative or positive control series using the χ²-test. The results of mutagenic study have demonstrated that rosemary and nutmeg were mutagenic using only the white/white+ (w/w+) eye SMART assay. The positive effects of liquorice and african rue were evident using both of the wing and the w/w+ SMART assays. The antimutagenic studies have demonstrated that all the spices and medicinal plants studied, except lemon verbena, showed antimutagenic activity against the direct mutagen MMs using pretreatments and/or cotreatments. This suggest that the antimutagens in these natural product exert their protective effect by interacting with MMS in desmutagenic manner. Verbena, liquorice and laurel have demonstrated to be able to inhibit the mutagenesis induced via bioantimutagenic manner. Using URE, black seeds, oregano and fenugreek seeds were effective against this promutagen using the cotreatments. Nutmeg, rosemary, and lemon verbena suppress significantly the mutagenesis induced by URE using both of cotreatments and of pretreatments. Laurel was active only using the pretreatments. These results indicate a possibility of a direct interaction between plants constituents and URE or its metabolites. Moreover, it seems likely that this suppressing effect arose through inhibition of metabolism of this indirect mutagen. Lastly, using the posttreatments, liquorice was the most active plant against URE. Nutemag, rosemary and laurel have demonstrated also an activity on the mutagenicity induced by this promutagen through the biomutagenic pathway.