Abstract
Conjugated linolenic acids (CLN) have been found at high content levels in some seed oils such as bitter gourd, pomegranate and catalpa. The dietary bitter gourd oil (BGO) containing 9cis (c) , 11trans (t) , 13t-CLN isomer caused significant reduction of the azoxymethane-induced colonic aberrant crypt foci (ACF) in rats. The BGO administration also lowered proliferating cell nuclear antigen (PCNA) -index and induced apoptosis in ACF. These findings suggest possible chemopreventive ability of CLN in colon carcinogenesis. CLN showed cytotoxic effect on mouse and human tumor cells and inhibited the expression of c-myc gene in caco-2 cells. These effects of CLN on cancer cells would be correlated with their anticancer activity found in vivo study. BGO administration also caused the accumulation of 9c, 11t-CLA isomer in the liver of rat and mouse, whereas CLN was hardly detected in the liver lipids, showing the enzymatic conversion of CLN to CLA in biological system. Since preliminary studies indicate that 9c, 11t-CLA isomer has an anticancer agent, the anticancer effect of CLN may be also due to the CLA converted from CIA.
