Influence of different forms of selenium supplementation on the oxidant balance in the rat liver

The aim of this study was to estimate the influence of the administration of two seleno organic compounds of different structures, as well as inorganic sodium selenite, on antioxidant parameters and lipid peroxidation in rat liver tissue. Adolescent male Wistar rats were treated through a stomach tube with saline (control), Na2SeO3 (group II), 4-(o-tolyl-)-selenosemicarbazide of 2-chlorobenzoic acid (chain structure - group III), 3-(2-chlorobenzoylamino-)-2-(o-tolylimino-)-4-methyl-4-selenazoline (ring structure - group IV) at a dose of 5 . 10(-4) mg of Se g(-1) of b.w. once a day for a period of 10 days. Liver homogenates were examined to determine total antioxidant status (TAS), the activities of antioxidant enzymes, superoxide dismutase (SOD) and glutathione peroxidase (GPx), the concentrations of ascorbic acid (AA) and reduced glutathione (GSH), as well as the concentration of malondialdehyde (MDA). TAS was significantly reduced in animals receiving selenoorganic compounds vs. control. SOD was unchanged and GPx decreased in all groups undergoing Se-administration vs. control. AA was decreased in group IV vs. both control and group II. GSH was unaltered vs. control in rats receiving selenocompounds. MDA was significantly decreased in group IV in comparison with all other groups. Selenium supplementation generally caused impairment of selected elements of antioxidant barrier, but the ring selenoorganic significantly decreased the lipid peroxidation level. Further studies with the use of diverse doses and longer supplementation periods, including studies concerning the action of selected selenoorganic compounds in pathological states, are needed to evaluate the usefulness of these substances as Se-supplements.