DNA-RAPD Fingerprinting and Cytogenetic Screening of Genotoxic and Antigenotoxic Effects of Aqueous Extracts of Costus Speciosus (Koen.)

The present study was conducted to investigate the genotoxic and/or antigenotoxic effect of aqueous extract of the traditional plant Costus speciosus (Koen.) that is used frequently for the treatment of various disorders in Saudi Arabia. Root tip meristems of Allium cepa were treated with elevated concentrations of Costus speciosus (Koen.), Samples were taken at 48h. of each concentration (2, 5, 10, 20 µg/mL) and subjected to cytogenetic and molecular genetics assays (DNA-RAPD fingerprinting). It was found that the extract has no clastogenic or mutagenic activities, mitotic index decreased mildly compared with the control. Frequency of chromosomal aberrations showed no significance in all concentrations at time of exposure. Most aberrations of the dividing cells were disturbance of chromosomes. The RAPD results demonstrated monomorphic numbers of genetic bands mostly, which were the electrophoretic products of PCR for all treatments compared with the control. Also the results exhibited the ability of C. speciosus as antigenotoxic and anticytotoxic potential against EMS induced DNA damage , cytotoxic and clastogenic effects in Allium cepa cells. The presented data showed that C. speciosus extract could not induce significantly genotoxic effect on Allium cepa cells. Furthermore, this study implies that combined treatment of C. speciosus has a strong inhibitory role against the genotoxic action of EMS. These results strongly suggest that the extract of Costus speciosus is not genotoxic, or cytotoxic but might be anti-genotoxic agent.