EFFECTS OF THE SULFORAPHANE ANALOG COMPOUND-30, INDOLE-3-CARBINOL, D-LIMONENE OR RELAFEN ON GLUTATHIONE S-TRANSFERASES AND GLUTATHIONE-PEROXIDASE OF THE RAT DIGESTIVE-TRACT

Several dietary compounds have been demonstrated to reduce gastrointes tinal cancer rates in both humans and animals, We showed that high hum an gastrointestinal tissue levels of glutathione S-transferase (GST), a family of detoxification enzymes consisting of class Alpha, Mu. Pi a nd Theta isoforms, inversely correlated with cancer risk. We now inves tigated whether the sulforaphane analog compound 30, indole-3-carbinol , D-limonene or relafen, supplemented in the diet for two weeks at 145 0, 250, 10 000, and 200 ppm, respectively, Influenced (i) GST activity , (ii) GST isoenzyme levels, (iii) GSH levels, or (iv) glutathione per oxidase (GPx) activity in the gastrointestinal tract of male Wistar ra ts. Sulforaphane analog compound 30 enhanced GST activity in all organ s studied (1.2-2.4 X), It induced GST Alpha levels in small intestine and liver, GST Mu levels in stomach and small intestine, GST Pi levels in stomach and small and large intestine, and GSH levels in stomach a nd proximal and middle small intestine. Indole-3-carbinol induced gast ric GST Mu and hepatic GST Alpha levels. D-limonene induced hepatic GS T Alpha, colonic GST Pi levels and proximal small intestinal GST enzym e activity and GST Pi levels. Relafen induced hepatic GST Alpha levels , distal small intestinal and gastric GST Pi al and proximal small int estinal GSH levels. GPx activity was enhanced by relafen in oesophagus , and in distal small intestine by sulforaphane analog compound 30. En hancement of GSTs and to a lesser extent GPx and GSH, resulting in a m ore efficient detoxification, may explain at least in part the anticar cinogenic properties of sulforaphane analog compound 30, and to a much lesser extent of indole-3-carbinol and D-limonene. (C) 1998 Elsevier Science B.V.