Differential growth inhibitory effects of W. somnifera root and E. officinalis fruits on CHO cells.

The Chinese Hamster ovary (CHO) cell line is widely used for measuring drug cytotoxicity and resistance. Therefore, the effects of two major Ayurvedic drugs (W. somnifera root and E. officinalis fruits) on the short and long-term growth of these cells were investigated. A standard 96-well plate assay was used to measure short-term growth. For assessment of long-term growth, the colony formation assay (CFA) was used, which measures clonogenic potential. This assay is the best measure of the cytotoxicity of anticancer drugs and the radio-sensitivity of tumor cells. As reported by others, the aqueous extracts of both herbal drugs were found to have short-term growth inhibitory effects on CHO cells when added to cells at the time of cell plating. However, this is the first report showing that these two herbal drugs have significantly different effects on the long-term growth of CHO cells. Thus, extracts of W. somnifera root, but not E. officinalis fruit, caused a reproducible, dose dependent, inhibition of colony formation of CHO cells.