EFFECT OF OLTIPRAZ, ALPHA-TOCOPHEROL, BETA-CAROTENE AND PHENETHYLISOTHIOCYANATE ON RAT ESOPHAGEAL, GASTRIC, COLONIC AND HEPATIC GLUTATHIONE, GLUTATHIONE-S-TRANSFERASE AND PEROXIDASE

Four anticarcinogens (oltipraz, alpha-tocopherol, beta-carotene and ph enethylisothiocyanate [PEITC]) were studied with respect to their effe cts on oesophageal, gastric, colonic and hepatic (i) glutathione (GSH) content, (ii) glutathione S-transferase (GST) enzyme activity, (iii) GST isoenzyme levels, and (iv) glutathione peroxidase (GPx) enzyme act ivity in male Wistar rats, GST enzyme activity was significantly incre ased in oesophagus (1.9x) and colon (1.2x) by PEITC and in liver (1.4x ) by oltipraz, GST Alpha was doubled in the liver by oltipraz, alpha-t ocopherol and PEITC. GST Mu levels were increased by beta-carotene and PEITC in stomach and liver, by oltipraz in liver and by alpha-tocophe rol in stomach, PEITC induced colonic GST Pi levels (1.3x), GSH conten t was induced in liver by oltipraz (1.4x) and alpha-tocopherol (1.2x) and in colon by PEITC (1.6x), Each of the anticarcinogens tested incre ased GPx activity at one or more sites: Se-dependent and total GPx act ivities were induced in 31.3% and 37.5% of all possibilities, respecti vely, Major induction in total GPx was found in stomach by alpha-tocop herol (1.8x), In conclusion our data demonstrate that dietary administ ration of oltipraz, PEITC, alpha-tocopherol and beta-carotene, may exe rt chemopreventive effects in the digestive tract of the rat by enhanc ing GST, GPx, and, to a lesser extent, GSH levels.