Evaluation of cyclophosphamide-induced genotoxicity and cytotoxicity in cultured human lymphocytes

Aim: The present study was aimed to examine and evaluate the genotoxicity and cytotoxicity induced by different doses of cyclophosphamide (CP) in normal healthy cultured human peripheral blood lymphocytes. Materials and Methods: Genotoxicity and cytotoxicity was evaluated through mitotic index (MI), chromosomal aberrations, micronuclei frequency, and colony formation assay (plating efficiency [PE] and survival fraction), respectively. Results: It has been observed that CP (1, 2.5, and 5 μg/ml)) induced a dose-dependent increase in chromosomal aberrations and micronuclei frequencies in cultured human peripheral blood lymphocyte as compared to normal. A significant increase was observed in the percentage of aberrant cells and dicentrics/exchanges at 1 and 2.5 μg/ml CP and aberrant cells, breaks, fragments, and dicentrics/exchanges at 5/μg/ml CP. A dose-dependent decrease in values of MI and nuclear division index was also observed in CP-treated group. The frequency of micronuclei in binucleated cells showed a dose-dependent increase. In colony formation assay, PE and surviving fraction values showed significant (P < 0.001) and dose-dependent decrease in the CP treatment groups. Conclusion: The results of present study suggest that CP has genotoxic and cytotoxic effect on cultured human lymphocytes.