Cytotoxic and apoptotic activities of extracts of withania somnifera and tinospora cordifolia in human breast cancer cells

Withania somnifera (WS) and Tinospora cordifolia (TC) have been used in the traditional system of medicine in India (Ayurveda) for the treatment of cancer. The current study investigated the cytotoxic and apoptotic effects of extracts of WS and TC on human breast cancer cells (MCF7 and MDA MB 231). MTT-based assays revealed dose-dependent cytotoxic effects of the ethanolic extracts of WS and TC in human breast cancer cells, while the aqueous extracts failed to induce significant cytotoxicity. Hoechst 33342 staining and DNA fragmentation assays revealed hallmark properties of apoptosis such as membrane blebbing, nuclear condensation, and DNA fragmentation. The ethanolic extracts of both WS and TC also increased the sub-G₀content, further confirming induction of apoptosis, while WS extracts additionally caused cell cycle arrest in the G₂/M phase. Further, the current study also evaluated the cytotoxic effects of WS and TC extracts on human immortalized but, 'non-cancerous' cell line (HaCaT). Significantly, the extracts failed to show cytotoxicity or apoptosis in HaCaT cells at the concentration that was cytotoxic to breast cancer cells, indicating less cytotoxic effects of WS and TC against human 'non-cancerous' cells. Thus, our study reveals potential anti-cancer activities of the ethanolic extracts of TC and WS against human breast cancer cells. Industrial relevance: The uses of WS and TC in traditional system of medicine for the management and treatment of cancer have drawn considerable attention. Varieties of pytochemicals and herbal formulations have been developed from plant sources, leading to the scientific interest in the discovery of anticancer agents from crude plant extracts. Medicinal plant extracts have played a significant role in the development of several clinically useful anti-cancer agents. Herbal formulations of the crude extracts could be useful for the treatment of breast cancer with less toxic effects against 'non-cancerous' cells. The identification of biologically active crude extracts possessing antiapoptotic activities against breast cancer cells shows their potential for drug discovery.