ABSTRACT
Two vitamin A2 compounds (3-dehydroretinol and 3-dehydroretinyl palmitate) which are predominantly present in fresh water fish have been found to be very effective in inhibiting the microsome catalysed formation of DNA adduct by the carcinogen aflatoxin B1. The inhibition appears to be due to modulation of microsomal enzymes which activate the carcinogen. Such inhibition may suggest a potential chemopreventive role of these compounds against carcinogenesis induced by aflatoxin B1.
Subject(s)
Aflatoxin B1/antagonists & inhibitors , Animals , Carcinogens/antagonists & inhibitors , Microsomes, Liver/drug effects , Rats , Vitamin A/analogs & derivativesABSTRACT
Administration of aflatoxin Β1 (3 mg/kg body wt) to rats leads to strong inhibition of the acceptor activity of liver tRNA as measured by charging with [14C] chorella protein hydrolysate. The maximum inhibition occurs 2 h after treatment. At increasing intervals after treatment, the inhibition appears to be gradually relieved, till control values are restored by 72 h. The charging experiment using several [14C] amino acids separately shows pronounced inhibition of acceptor activity of all tRNA species, although the degree of inhibition varies with individual species. Preliminary results seem to rule out the possibility of hypermethylation of tRNA or damage to the CCA terminus as probable causes. The resultant functional changes may be attributed to a covalent interaction of aflatoxin Β1 metabolite with tRNA.