Abstract
Ganoderma lucidum (GL) and its polysaccharide and phenolic constituents were reported to possess antioxidant activity, to inhibit lipid peroxidation, and to scavenge free radicals. However, the information to the effect of GL on oxidative damage induced by exhaustive exercise is scanty. PURPOSE: To investigate the exhaustive exercise-induced oxidative stress and the protective effect of GL supplementation on malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GPx) in rat liver. METHODS: Forty male Sprague- Dawley rats were randomly divided into the following four groups: 1.control (C, n=10), 2.exhaustive exercise (E, n=10), 3.GL (G, n=10), 4.GL-exhaustive exercise (GE, n=10). The amount of GL supplementation was 40 mg/day/kg wt for 4 weeks. The exhaustive exercise started at 10% grade, 15 m/min for 10 min followed by gradual increases of treadmill speed and times as 25 m/min for 20 min, 28 m/min for 20 min, 31 m/min for 20 min, 34 m/min for 20 min, 37 m/min for 20 min, until exhaustion. Two way ANOVA was performed to examine the effects of exhaustive exercise and GL supplementation on MDA, SOD, and GPx activities. RESULTS: Exercised duration in GE group (60.51 ± 5.33 minutes) was significantly higher than E group (48.98 ± 7.21 minutes). The results showed that MDA in the exhaustive exercise rat liver (10.45 ± 2.10 μm/mg protein) was significant higher (p<.05) than C group (5.85 ± 1.17 μm/mg protein), G group (3.32 ±.86 μm/mg protein) and GE group (5.88 ± 1.53 μm/mg protein). SOD activity of rat liver in GL supplemental group (24.47 ± 4.89 U/mg protein) was significant higher (p<.05) than non-GL supplemental group (13.86 ± 3.29 U/mg protein), while SOD activity of rat liver in exhaustive exercise group (17.82±3.96 U/mg protein) was significant lower than non-exercise group (20.50 ± 4.22 U/mg protein). Moreover, GPx activity of rat liver in GL supplemental group (370.27 ± 26.61 μU/mg protein) was significant higher (p<.05) than non-GL supplemental group (297.35 ± 19.82 μU/mg protein), while there was not significant difference between exhaustive exercise and non-exercise group in GPx activity of rat liver. CONCLUSIONS: It is concluded that exhaustive exercise could result in oxidative stress. However, GL supplementation is beneficial to decrease oxidative stress and increase antioxidant status.