Withaferin A, a steroidal lactone isolated from the roots of the Indian medicinal plant Withania somnifera, reduced survival of V79 cells in a dose-dependent manner. LD50 for survival was 16 μM. One-hour treatment with a nontoxic dose of 2.1 μM before irradiation significantly enhanced cell killing, giving a sensitizer enhancement ratio (SER) of 1.5 for 31% survival and 1.4 for 10% survival. SER increased with drug dose, but at higher doses the increased lethality appears to be due to two effects-drug toxicity and radiosensitization. The drug induced a G2-M block, with a maximum accumulation of cells in G2-M phase at 4h after treatment with 10.5 μM withaferin A for 1 h. The applicability of this drug as a radiosensitizer in cancer therapy needs to be explored.
All Science Journal Classification (ASJC) codes
- Radiological and Ultrasound Technology
- Radiology Nuclear Medicine and imaging