CHEMOPREVENTION OF DIGESTIVE ORGANS CARCINOGENESIS BY NATURAL PRODUCTPROTOCATECHUIC ACID

The worldwide increase in cancer mortality demands a practical and eff ective chemopreventive approach to this problem. Using animal bioassay , the authors demonstrated protocatechuic acid (PCA, 3,4-dihydroxybenz oic acid), a simple and antioxidative phenolic acid present in fruits, vegetables, and nuts, to be an efficacious agent in reducing the carc inogenic action of 4-nitroquinoline 1-oxide in oral cavity, N-methyl-N -nitrosourea in glandular stomach, azoxymethane in colon, and diethyln itrosamine in liver. PCA exerts its chemopreventive action partly thro ugh inhibition of cell proliferation induced by carcinogens in the tar get organs. The prospect of this agent as chemopreventive against huma n cancer warrants a thorough investigation, such as dose-dependent eff icacy and its potential toxicity at an effective dose level in other s pecies of animals. Considering its promising anticarcinogenic potency, proliferation biomarkers, including tissue and blood polyamine levels , might eventually be useful in assessing the possible role of PCA int ake in high risk populations for cancers of these organs.