EFFECT OF ORAL AND PARENTERAL ADMINISTRATION OF METANIL-YELLOW ON SOME HEPATIC AND INTESTINAL BIOCHEMICAL PARAMETERS

Metanil yellow, a non-permitted colour for food commodities, is used i n the leather, paper and textile industries. In this paper the effect of oral and parenteral administration of Metanil yellow on hepatic and intestinal biochemical parameters was investigated. Oral administrati on of Metanil yellow (430 mg kg(-1) body wt.) for 7 days caused signif icant depletion of hepatic and intestinal glutathione levels (33-52%) with a concomitant increase in lipid peroxidation (49-121%). Metanil y ellow treatment for 7 days also led to a significant increase in cytoc hrome P-450 (P-450)-dependent aryl hydrocarbon hydroxylase (AHH) activ ity (99-223%) in the liver and intestine. Cytosolic glutathione-S-tran sferase (GST) (32-136%) and quinone reductase (QR) (20-92%) activities were also found to be substantially induced in hepatic and intestinal tissues following oral treatment of Metanil yellow. It is interesting to note that oral treatment of Metanil yellow showed a greater respon se in cytosolic enzymes of hepatic tissue as compared to intestine. Si ngle parenteral administration of Metanil yellow (80 mg kg(-1) body wt ,) caused significant induction of P-450 and its dependent monooxygena ses. Even after 5 days of single parenteral administration of Metanil yellow, hepatic AHH activity showed an elevation of 48% while other mo nooxygenases were marginally increased. Cytosolic GST and QR showed re spective peak inductions of 92% and 60% after 2 and 3 days of parenter al administration of Metanil yellow, which levels off after the 5th da y. It can be concluded that Metanil yellow acts as an inducer of a spe cific form of microsomal P-450 and cytosolic GST and QR, which may inv olve a cytosolic Ah receptor. (C) 1996 by John Wiley & Sons, Ltd.