Hibiscus protocatechuic acid protects against oxidative stress induced by exhaustive exercise in rat lung

Introduction

Hibiscus protocatechuic acid (PCA) is a simple phenolic compound isolated from the dried flowers of Hibiscus sabdariffa L., a Chinese herbal medicine. PCA has been reported to reduce the formation of lipid peroxidation and to be an effective antioxidant. It is well known that oxygen consumption is a direct function of workload. One consistent finding is that exhaustive exercise may increase the production of oxygen free radicals and that lipid peroxidation may be increased. The purpose of this study was to investigate the exhaustive exercise-induced oxidative damage and the protective effect of supplementation of PCA on malonyldialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), and glutathione peroxidase (GPx) in rat lung.

Methods

Thirty two male Sprague-Dawley rats were randomly divided into the following four groups: 1.control (C, n=8), 2.exhaustive exercise (E, n=8), 3.PCA (P, n=8), 4. PCA- exhaustive exercise (PE, n=8). The amount of PCA supplementation was 1 mg/kg mass body per day for 7 days. The exhaustive exercise started at 10% grade, 15 m/min for 15 min followed by gradual increases of treadmill speed and times as 25 m/min for 15 min, 30 m/min for 30 min, 35 m/min for 60 min, 40 m/min for 30 min, 45 m/min for 30 min until exhaustive. Exercised duration in E and PE groups were 91.8 23.6 and 107.6 22.3 minutes, respectively. Two way ANOVA was performed to examine the effects of exhaustive exercise and PCA supplementation on MDA, SOD, GSH, and GPx activities.

Results

The finding in this study indicated that MDA (.92±.16 mg/ml) in the exhaustive exercise rat lung was significant higher (p<.05) than C group (.62±.12 mg/ml), and P group (.68±.16 mg/ml). SOD activity in P (10.81±1.45 U/ml) and PE (9.98±1.06 U/ml) group was significant higher (p<.05) than E group (8.28±.63 U/ml). GSH concentration was significant decreased in exhaustive exercise group (13.47±1.20 mg/ml) compared with other groups, but no significant change between P (17.67±1.23 mg/ml) and PE (18.84±1.45 mg/ml) groups.

Discussion/Conclusions

It is concluded that exhaustive exercise could result in oxidative stress. However, the PCA supplementation is beneficial to increase antioxidant status and inhibit oxidative induced by exhaustive exercise.
Supported by National Science Council, Grant # 88-2413-H-134-010.

References

[1]. Lin WL, et al. (2003). Arch Toxicol. 77(1):42-7.
[2]. Liu CL, et al. (2002). Food Chem Toxicol. 40(5):635-41.
[3]. Tseng TH, et al. (1996). Chem Biol Interact. 101(2):137-48.
[4]. Banerjee AK, et al. (2003). Mol Cell Biochem. 253(1-2):307-12.
[5]. Groussard C, et al. (2003). Eur J Appl Physiol. 89(1):14-20.