Evaluation of selected indigenous medicinal plants from the western Himalayas for cytotoxicity and as potential cancer chemopreventive agents

The western Himalayas in the northern areas of Pakistan have significant potential for ethnomedicinal research. In the current study, indigenous informants were interviewed using open-ended questionnaires and a free-listing of knowledge related to native medicinal plants. Information patterns indicated that over 100 local plant species were in frequent medicinal use for a variety of conditions, including inflammation and cancer. Several field surveys were conducted in community forests and meadows, with the aim of exploration, collection, taxonomic identification, and finally, in vitro analysis. Organic extracts of eight species were tested for inhibition of nuclear factor-kappaB (NF-κB), activation of retinoic acid X receptor alpha (RXR), induction of quinone reductase (QR), and inhibition of aromatase, along with assessment of cytotoxicity with four human cancer cell lines. Mellia azedarach, Ajuga bractiosa, Figonia cretica and Swertia chirata inhibited both tetradecanoylphorbol-13-acetate (TPA) and tum...