Plant-derived anticancer agents.

Natural product drugs play a dominant role in pharmaceutical care. This is especially obvious in the case of antitumor drugs, as exemplified by paclitaxel (Taxol), vincristine (Oncovin), vinorelbine (Navelbine), teniposide (Vumon), and various water-soluble analogs of camptothecin (e.g., Hycamtin). The most efficient method of discovering drugs such as these (i.e. novel chemical prototypes that may function through unique mechanisms of action) is bioactivity-guided fractionation, and it is certain that additional natural product drugs, some of which should be useful for the treatment of humans, remain to be discovered. For the commercial procurement of structurally complex natural product drugs, isolation from plant material may be most practical. With the advent of combinatorial chemistry and high throughput screening, however, even greater progress may now be expected with natural product leads. While systemic drug therapy, to an appreciable extent based on natural products, has been the mainstay of pharmaceutical care, the logic of disease prevention is overwhelming. Bearing in mind the pandemic nature of cancer, a proposal is put forth to create a cancer chemoprevention drug formulation for utilization on a widespread basis by the general population. Cancer chemopreventive agents, many of which are natural products, are capable of preventing or inhibiting the process of carcinogenesis. As with other pharmaceutical agents useful for disease prevention, a pharmacoeconomic analysis of a cancer chemopreventive formulation would need to be considered, and the composition of the formulation should improve over time. Nonetheless, implementation should commence immediately.