Anticancer Activity of Isolated Constituents from Aralia Racemosa L and Argyreia Pilosa Wight & Arn by Sulphorhodamine (SRB) Assay on Ishikawa and SCC-29B Cell Lines

A significant part of drug discovery in the last forty years has been focussed on agents to prevent or treat cancer. This is not surprising because, in most developed countries and, to an increasing extent, in developing countries, cancer is amongst the three most common causes of death and morbidity. Treatments for cancer may involve surgery, radiotherapy and chemotherapy and often a combination of two or all three is employed. Natural compounds from flowering plants play a significant role in cancer chemotherapy. Anticancer drugs in wide clinical use include vincristine and vinblastine from Catharanthus roseus, palitaxel (Taxol) and taxotere from species of yew (Taxus), etoposide derived from lignans of Podophyllum spp. and camptothecin analogues, such as topotecan, from Camptotheca acuminata. All of these are fundamentally cytotoxic and act principally by inhibiting cell proliferation, but by different mechanisms. In fact, some natural products have been found to act by novel mechanisms and so have enabled novel targets to be developed for screening, exemplified by the discovery that paclitaxel inhibited mitosis by stabilising microtubules and so preventing their depolymerisation back to tubulin, in contrast to many other anticancer agents which inhibit the formation of microtubules in the first place [1].