Abstract
The purpose of this study was to investigate the exhaustive exercise (CE) induced oxidative damage and the protective effect of Hibiscus protocatechuic acid (PCA) supplementation on malonyldialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione reductase (GRd) in rat skeletal muscle. Thirt-two male Sprague-Dawley rats were randomly divided into the following four groups: (i) control (C, n = 8), (ii) exhaustive exercise (CE, n = 8), (iii) PCA (P, n = 8), and (iv) PCA-exhaustive exercise (PE, n = 8). The amount of PCA supplementation was 1 mg per kg mass body per day for 7 days. The exhaustive exercise started at 10% grade, 15 m min <sup>-1</sup> for 15 min followed by a gradual increase of treadmill speed and times as 25 m min <sup>-1</sup> for 15 min, 30 m min <sup>-1</sup> for 30 min, 35 m min <sup>-1</sup> for 60 min, 40 m min <sup>-1</sup> for 30 min, 45 m min <sup>-1</sup> for 30 min until exhaustion. Exercised duration in CE and PE groups were 91.8 ± 23.6 and 107.6 ± 22.3 min (p>0.05), respectively. Two-way analysis of variance was performed in this study. The results of this study showed that MDA activity was 192% higher in CE versus C rats and 42% lower in PE versus CE rats (p<0.05). SOD activity was 49% lower in CE versus C rats and 69% higher in PE versus CE (p<0.05). Moreover, GRd activity was 50% higher in PE versus versus CE rats (p<0.05). It was concluded that exhaustive exercise could result in oxidative stress. The PCA supplementation was beneficial in enhancing antioxidant status and inhibiting oxidative stress induced by exhaustive exercise.