Genotoxic and Cytotoxic Activities of Hippocratea africana Loes. Ex. Engl. Celastraceae Root Extract

Hippocratea africana, a medicinal plant, used in ethnomedicine for the treatment of antimalarial, diabetes, poisoning and inflammatory diseases was investigated for cytotoxic and genotoxic effects on the root meristem cells of Allium cepa. The extract and fractions was also screened for total flavonoid and phenol content using standard methods. Onion bulbs were exposed to 2.5 mg/ml, 5mg/ml, and 10 mg/ml concentrations of the leaf extract for macroscopic and microscopic analysis. Tap water was used as a negative control and Methotrexate (0.1 mg/ml) as a positive control. There was statistically significant (P < 0.05) inhibition of root growth depending on concentration by the extract when compared with the negative control group. All the tested concentrations of the extract were observed to have cytotoxic effects on cell division in A. cepa. The extract- induced chromosomal aberrations and micronuclei (MNC) formations in A. cepa root tip cells and were significant (p<0.05) when compared with control group. The extract treatment further induced cell death, ghost cells, cells membrane damage, and binucleated cells. These results suggest that Hippocratea africana root extract possess cytotoxic and genotoxic effects on A. cepa which is as a results of its phytochemical constituents.