Antimutagenic activity of two medicinal phytoextracts in somatic cells of Drosophila melanogaster.

Laboratorio de Genética, Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Coyoacán, México, D.F. México.
Pharmaceutical Biology (Impact Factor: 1.21). 03/2011; 49(6):640-7. DOI: 10.3109/13880209.2010.527992
Source: PubMed

ABSTRACT We used the wing somatic assay in Drosophila melanogaster to test the hypothesis that two phytoextracts from Cecropia obtusifolia Bertol (Cecropiaceae) and Equisetum myriochaetum Schlecht. et Cham (Equisetaceae), which are used in folk medicine to treat type 2 diabetes mellitus, could detoxify the mutagen hydrogen peroxide.
Third instar larvae from standard (ST) and high-bioactivation (HB) crosses were chronically exposed to different concentrations of the phytoextracts. Hydrogen peroxide was used to induce oxidative stress and was chronically tested in both crosses. Catalase activity was measured in larvae of both strains 48 h after treatment with hydrogen peroxide. A pretreatment protocol was devised to test the antimutagenic potency of the medicinal extracts.
The present study showed that neither of the phytoextracts were genotoxic in Drosophila. Interestingly, the antioxidant enzyme activity levels were different between the larvae. Hydrogen peroxide resulted in a significant genotoxic effect in the ST cross, whereas a detoxification of hydrogen peroxide was found in the HB cross. Thus, catalase was stimulated in the HB cross, which was indicative of a cellular defense mechanism mounted against a xenobiotic hazard. We found that the percentage of inhibition of spots produced by E. myriochaetum was much higher than that induced by Cecropia obtusifolia.
These results are in agreement with the uses of these phytoextracts in traditional medicine. Indeed, the lack of genotoxicity and the antimutagenic activity observed for both phytoextracts validates their use as a therapeutic modality to treat diabetic patients. Moreover, these extracts are suitable for consumption as teas and/or phytomedicines.

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    ABSTRACT: Flavonoids are a family of antioxidants that are widely represented in fruits, vegetables, dry legumes, and chocolate, as well as in popular beverages, such as red wine, coffee, and tea. The flavonoids chlorogenic acid, kaempferol, quercetin and quercetin 3β-d-glycoside were investigated for genotoxicity using the wing somatic mutation and recombination test (SMART). This test makes use of two recessive wing cell markers: multiple wing hairs (mwh) and flare (flr(3)), which are mutations located on the left arm of chromosome 3 of Drosophila melanogaster and are indicative of both mitotic recombination and various types of mutational events. In order to test the antioxidant capacities of the flavonoids, experiments were conducted with various combinations of oxidants and polyphenols. Oxidative stress was induced using hydrogen peroxide, the Fenton reaction and paraquat. Third-instar transheterozygous larvae were chronically treated for all experiments. The data obtained in this study showed that, at the concentrations tested, the flavonoids did not induce somatic mutations or recombination in D. melanogaster with the exception of quercetin, which proved to be genotoxic at only one concentration. The oxidants hydrogen peroxide and the Fenton reaction did not induce mutations in the wing somatic assay of D. melanogaster, while paraquat and combinations of flavonoids produced significant numbers of small single spots. Quercetin 3β-d-glycoside mixed with paraquat was shown to be desmutagenic. Combinations of the oxidants with the other flavonoids did not show any antioxidant activity.
    Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis 09/2011; 726(1):60-5. · 4.44 Impact Factor


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May 27, 2014