This study attempts to determine whether
selenomethionine treatment can 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. Accordingly, a maximum of 30.76 and 143% increase in survival was brought about by treatment of
selenomethionine prior to
lymphoma transplantation, in comparison to mice receiving selenomethione supplementation concurrently with inoculation of DL, and those
tumor-bearing mice receiving no supplementation, respectively. Beneficiality of
selenomethionine has also been studied by monitoring the continuous changes brought about by this compound on hepatic total
cytochrome P-450 and b5 content,
NADPH cytochrome c reductase,
UDP glucuronyl transferase and
glutathione S-transferase (GST) activities. These are important biotransformation
enzymes and are altered significantly in
neoplasia. The drastic increase in all the markers studied, excepting GST, was effectively counteracted by
selenomethionine treatment (more before than concurrently), which sufficiently delayed and controlled the increase in those
xenobiotic indices. The 112 and 78.78% induction in GST activity brought about by prior and concurrent treatment of
selenomethionine, respectively, confirms the fact that inducers of
GSTs are often antitumorigenic.