Sensitivity of hematopoietic malignant cells to Peganum harmala seed extract in vitro

Background and Objective: Peganum harmala is a medicinal plant that has been used for treatment of numerous diseases including viral, bacterial and parasitic infections. Anti-proliferative and anti-tumor effects of Peganum harmala extracts and its derivatives have been reported. In the present study, cytotoxic effect of Peganum harmala seeds aquaous extract on leukemic U937 and Molt-4 cells was evaluated in vitro. Materials and Methods: U937 and Molt-4 cells were cultured in RPMI with 10% FBS. Then, the cells at logarithmic growth phase were incubated with different concentrations of aquaous extract of Peganum harmala seeds (0.1-5 mg/ml) for 24, 48 and 72 hours. Then, viability and proliferative response of leukemic cell lines was evaluated by trypan blue dye exclusion (TB) and MTT assays, respectively. Results: Peganum harmala aquaous extract has a cytotoxic effect on leukemic cells used in this study, dose and time-dependently. This cytotoxicity was shown at ≥ 0.5 mg/ml after 24 hours and at ≥ 0.1 mg/ml after 48 and 72 hours incubation time. The Peganum harmala seeds aqueous extract cytotoxicity at > 0.2 mg/ml concentration was significantly increased with time in this order: 72 h>48 h>24 h. Conclusion: The leukemic cells used in this study showed sensitivity to Peganum harmala seeds aquaous extract dose and time dependently. This sensitivity significantly increased with time at > 0.2 mg/ml concentration. Peganum harmala seeds aquaous extract shows cytotoxicity for leukemic cells and might be a valuable natural candidate in development of innovative therapeutic procedures for leukemia and probably other cancers.