Indian Ayurvedic medicine: Overview and application to brain cancer.

Ayurveda is the traditional medicine system of India, and has been in practice for millennia. It is a traditional approach that uses 1000's of different plant preparations in various combinations for treatment of human ailments, including cancer. Ethnopharmacological and phytochemical analyses are now elucidating the bioactive constituents of the different plant species and herbal formulations, including ashwagandha, curcumin, guduchi, triphala, and others. To provide an overview of: 1) the ethnopharmacology of Ayurveda and several of its most important plant species and formulations, including pharmacological and molecular mechanisms of its anti-cancer effects; 2) review the literature applying Ayurvedic herbs and formulations to brain tumors. A detailed PubMed search was performed that included publications involving Ayurveda, cancer, ethnopharmacology, phytochemical analysis, molecular analysis, and brain tumors. In recent decades, significant research has begun to elucidate the bioactive compounds of ashwagandha, tumeric, guduchi, and triphala, such as withaferin A, withanolides, curcumin, palmatine, and many others. These compounds and extracts are now being applied to brain tumor cells in vitro and in animal models, with positive signs of anti-cancer activity including reduced cell growth, increased apoptosis, cell cycle arrest, increased differentiation, and inhibition of important internal signal transduction pathways. Several Ayurvedic herbs (ashwagandha, curcumin) have bioactive compounds with significant anti-cancer activity, and are effective in early pre-clinical testing against brain tumor cells in vitro and in animal models. Further pre-clinical testing is warranted, along with advancement into phase I and phase II clinical trials of patients with glioblastoma and other brain tumors.