Alleviation of doxorubicin (DOX)-induced cytotoxicity and genotoxicity by leaf extract of bael also known as Aegle marmelos (AME) was studied in cultured Chinese hamster V79 cells. The optimum protective dose of AME was determined by treating V79 cells with different concentrations of AME before exposure to 10 µg/ml DOX and then by evaluating the cell survival and micronuclei frequency in the cytokinesis blocked V79 cells. MTT assay results revealed that AME pretreatment resulted in a concentration dependent elevation in the cell survival up to 25 μg/ml, whereas a further increase in AME concentration reduced the cell survival. Assessment of DNA damage by micronuclei assay showed that 25 µg/ml AME reduced the micronuclei frequency to a maximum extent. Therefore, 25 μg/ml AME was considered as an optimum chemo-protective concentration and further studies were carried out using this concentration, where V79 cells were treated with 25 μg/ml AME before exposure to different concentrations of DOX. The results of MTT assay at various post-DOX treatment times showed a time and concentration dependent decline in the cell survival with a maximum decline at 72 h post-DOX treatment. The IC50 values of 122, 108, 88 and 47 µg/ml DOX was observed at 12, 24, 48 and 72 h post-DOX treatment, respectively. Treatment of V79 cells with 25 μg/ml AME before DOX exposure to different concentrations of resulted in a rise in the IC50 by 60, 24, 44 and 41 µg/ml at 12, 24, 48 and 72 h, respectively. These results were corroborated by clonogenic assay where DOX-treatment caused a concentration dependent decline in the cell survival; whereas treatment of V79 cells with 25 µg/ml AME before DOX exposure arrested the DOX-induced decline in the cell survival. The micronuclei frequency increased in a concentration dependent manner in cells exposed to DOX, whereas AME pretreatment significantly reduced the DOX-induced micronuclei formation. Our results suggest that AME did reduce the cytotoxic and genotoxic effects of DOX and may be useful in clinical setup to reduce DOX-induced toxicity.
Key words: V79 cells, Aegle marmelos, doxorubicin, MTT, cell survival, micronuclei.