Ayurvedic herbal drugs with possible cytostatic activity.

Ayurveda is considered to be the traditional science of health in India and is based on the principle of subjectivity. All matter is composed of five basic elements, which can be perceived by the five sense organs. All food and drugs are classified according to their pharmacological properties, which are derived from these five elements. To investigate which Ayurvedic plants might have cytostatic activity, an Ayurvedic model for the pathogenesis of cancer was made. Based on this, selection criteria were formed, that were used to select plants from a list of Ayurvedic herbal drugs. Some of the selected species could be collected in India and Nepal. The dried material of 14 species was submitted to ethanol (70% v/v) extraction and the extracts were tested for cytotoxicity on COLO 320 tumour cells, using the microculture tetrazolium (MTT) assay. The IC50-value, the concentration causing 50% growth inhibition of the tumour cells, was used as a parameter for cytotoxicity. Extracts of the flowers of Calotropis procera (Ait.) R. Br. (Asclepiadaceae) and of the nuts of Semecarpus anacardium L.f. (Anacardiaceae) displayed the strongest cytotoxic effect with IC50-values of 1.4 micrograms/ml and 1.6 micrograms/ml, respectively. The extracts of several other plants did not show a cytotoxic effect up to 100 micrograms/ml, the highest concentration tested.