SELENOMETHIONINE IN THE INHIBITION OF A TRANSPLANTABLE MURINE LYMPHOMA - REFLECTION ON HEPATIC DRUG-METABOLIZING-ENZYMES

This study attempts to determine whether selenomethionine treatment ca n improve the survival time of mice inoculated with Dalton's lymphoma (DL) and thereby to identify phase/ phases of the neoplastic processes at which selenium exerts its maximal action as an anticancer agent. A ccordingly, a maximum of 30.76 and 143% increase in survival was broug ht about by treatment of selenomethionine prior to lymphoma transplant ation, in comparison to mice receiving selenomethione supplementation concurrently with inoculation of DL, and those tumor-bearing mice rece iving no supplementation, respectively. Beneficiality of selenomethion ine has also been studied by monitoring the continuous changes brought about by this compound on hepatic total cytochrome P-450 and b(5) con tent, NADPH cytochrome c reductase, UDP glucuronyl transferase and glu tathione S-transferase (GST) activities. These are important biotransf ormation enzymes and are altered significantly in neoplasia. The drast ic increase in all the markers studied, excepting GST, was effectively counteracted by selenomethionine treatment (more before than concurre ntly), which sufficiently delayed and controlled the increase in those xenobiotic indices. The 112 and 78.78% induction in GST activity brou ght about by prior and concurrent treatment of selenomethionine, respe ctively, confirms the fact that inducers of GSTs are often antitumorig enic.