These scientists looked at the effect of curcumin, the active component of tumeric, on colon (large intestine) cancer of male F344 rats. Azoxymethane is a substance used in cancer research to cause colon tumors in animals. In the this study azoxymethane (AOM) was used to stimulate the cancer pathways, including the ornithine decarboxylase (ODC) and tyrosine protein kinase (TPK). It also increased the arachidonic acid cascade (another cancer pathway) and produced aberrant crypt foci in the colon. These foci are an early change in the colon leading to cancer. Group of rats were fed diets containing either no curcumin or 2000 parts per million at five weeks of age. Two weeks later all animals were injected under the skin with AOM once weekly for two weeks. Curcumin significantly decreased the levels of ODC and TPK activity, and the formation of numerous arachidonic acid cascade products in the liver and colon. These products included 5(S)-, 8(S)-, 12(S)- and 15(S)-hydroxyeicosatetraenoic acids, thromboxane and prostaglandins. Also, dietary curcumin reduced the formation of these products in the test tube, in liver and colon cells taken from the treated rats. A greater dose of curcumin reduced the products more. Aberrant crypt foci caused by AOM were significantly less in the animals fed curcumin. These findings show that curcumin inhibits precancerous lesions and pathways caused by AOM in the colon of rats.
Inhibition by dietary curcumin of azoxymethane-ind…[Carcinogenesis. 1993]