SELENIUM-ENRICHED AGARICUS BISPORUS MUSHROOM REGULATES COLONIC SELENOPROTEIN EXPRESSION IN RATS DIFFERENTLY UNDER THERMONEUTRAL AND HYPERTHERMAL STRESS CONDITIONS

Rats under thermoneutral conditions and fed mushroom-Se in dietary supplementation showed a significant fold increase (P<0.05) in mRNA expression relative to basal treatment (thermoneutral, control diet) of GPx-1 (2.98±0.82), GPx-2 (1.8±1.4), TrxR-1 (1.83±0.64) and SeP (2.77±0.92). Supplementation with α-tocopherol alone affected the expression of GPx-1 (1.83±0.82) and SeP (2.21±0.92). Rats subjected to heat stress and fed the control diet showed significant fold increase (P<0.05) in mRNA expression relative to the basal treatment of GPx-1 (3.15±0.82) and SeP (1.93±0.92). The expression of GPx-2 (3.2±1.4) and SeP (4.23±0.92) in rats fed mushroom-Se and expression of TrxR-1 (4.10±0.64) and SeP (7.44±0.92) in rats fed α-tocopherol alone were higher. Total colonic cellular GPx activity increased 3.8 fold in rats under thermoneutral conditions and fed the mushroom-Se diet compared to basal treatment. Heat stress had a negative impact on the colonic GPx activity which was recovered by mushroom-Se, but not α-tocopherol.