Throughout history, natural products have played a dominant role in the treatment of human ailments. For example, the legendary discovery of
penicillin transformed global existence. Presently, natural products comprise a large portion of current-day pharmaceutical agents, most notably in the area of
cancer therapy. Examples include
Taxol,
vinblastine, and
camptothecin. These structurally unique agents function by novel mechanisms of action; isolation from natural sources is the only plausible method that could have led to their discovery. In addition to terrestrial plants as sources for starting materials, the marine environment (e.g.,
ecteinascidin 743,
halichondrin B, and dolastatins), microbes (e.g.,
bleomycin,
doxorubicin, and staurosporin), and slime molds (e.g.,
epothilone B) have yielded remarkable
cancer chemotherapeutic agents. Irrespective of these advances,
cancer remains a leading cause of death worldwide. Undoubtedly, the prevention of human
cancer is highly preferable to treatment.
Cancer chemoprevention, the use of
vaccines or pharmaceutical agents to inhibit, retard, or reverse the process of
carcinogenesis, is another important approach for easing this formidable public health burden. Similar to
cancer chemotherapeutic agents, natural products play an important role in this field. There are many examples, including
dietary phytochemicals such as
sulforaphane and
phenethyl isothiocyanate (cruciferous vegetables) and
resveratrol (grapes and grape products). Overall, natural product research is a powerful approach for discovering biologically active compounds with unique structures and mechanisms of action. Given the unfathomable diversity of nature, it is reasonable to suggest that chemical leads can be generated that are capable of interacting with most or possibly all therapeutic targets.