Radiosensitizing activity of the Indian medicinal plant Tinospora cordifolia Miers Ex h\Hook f & Thoms in tumour-bearing mice.

Abstract

The present work describes the radiomodulatory activity of dichloromethane extract of Tinospora cordifolia in mice bearing Ehrlich ascites carcinoma (EAC). The final dichloromethane extracts (TCE) were concentrated and dried under reduced pressure. An approximate yield of 1.2% w/w was obtained. Ten- to twelve-week-old female Swiss albino mice weighing 30 to 36g were selected from an inbred colony and maintained under controlled conditions. 10⁶ viable EAC cells were injected intraperitoneally into each animal under aseptic conditions and the day of tumour inoculation was considered as day 0. TCE was dissolved in 100 µl of ethanol and diluted with normal sterile saline (SPS) containing 1% carboxymethyl cellulose (CMC). Both SPS and TCE were administered intraperitoneally. Separate experiments were conducted to evaluate the effects of altered administration regimen of TCE (pre-irradiation and post-irradiation) and the effects of irradiation and TCE administration on blood chemistry (levels of glutathione and glutathione-S-transferase and lipid peroxidation). In general, it was found that the radiosensitizing effect of TCE could be attributed to the depletion of glutathione and glutathione-S-transferase, accompanied by elevated levels of lipid peroxidation and DNA damage of tumour cells. The use of T. cordifolia may offer an alternative treatment strategy for cancer in combination with gamma radiation.