Anti-Genotoxicity Evaluation of Cratoxylum Formosum Dyer Leaves by Comet Assay and Micronucleus Test

Abstract

<br /> <em><span style="font-size: small;">Cratoxylum formosum </span></em><span style="font-family: Times New Roman,Times New Roman; font-size: small;"><span style="font-family: Times New Roman,Times New Roman; font-size: small;">Dyer is the Thai vegetable which commonly consumed a fresh leaves. In this study, we extracted </span></span><em><span style="font-size: small;">Cratoxylum formosum </span></em><span style="font-family: Times New Roman,Times New Roman; font-size: small;"><span style="font-family: Times New Roman,Times New Roman; font-size: small;">with water and tested the extract for genotoxicity and anti-genotoxicity effects. We carried out the experiment using micronucleus test and comet assay in TK6 cells. In micronucleus experiment, we used cytokinesis-block proliferation technique to stop cell division which produced a cell at binucleated (BNC) stage. The comet assay was carried out after pre-treatment the cell with C. formosum for 18 h. The results revealed not increased the micronucleus frequency of C. formosum at concentration ranging from 50-150 μg/ml. In contract, it showed that the combination between C. formosum at various concentrations (25, 50, 75, 100, 150 and 200 μg/ml) and mitomycin </span></span><span style="font-family: Times New Roman,Times New Roman; font-size: small;"><span style="font-family: Times New Roman,Times New Roman; font-size: small;">C could decrease significantly in frequency of micronuclei. The mean of micronucleus frequency in the sample were </span></span><span style="font-family: Times New Roman,Times New Roman; font-size: small;"><span style="font-family: Times New Roman,Times New Roman; font-size: small;">23.17 ±3.33, 23.33 ±4.72, 21.00 ±3.61, 11.33 ±3.21, 16.67 ±2.08, and 23.33±1.53 MN/ 1,000 BNC, respectively whereas the MMC-treated group was 33.67 ± 8.96 MN/ 1,000 BNC. The comet assay result showed that pre-treatment with </span></span><em><span style="font-size: small;">Cratoxylum formosum </span></em><span style="font-family: Times New Roman,Times New Roman; font-size: small;"><span style="font-family: Times New Roman,Times New Roman; font-size: small;">(25, 50, 100, 200 μg/ml) could inhibit the hydrogen peroxide induced DNA damage by 6.95, 12.99, 17.61, and 26.39 respectively. </span></span>