Effect Of Creatine Supplementation On Antioxidation Of Exercise Rats

Introduction
Creatine is a popular nutritional supplement among athletes. Recent research suggested that creatine had the potential to
act as a direct antioxidant [1]. The present study will investigate whether creatine could deliver an antioxidant effect
during exercise

Methods
Mature male Sprague-Dawley rats were randomly assigned to three groups: sedentary control group (SE, N=8),
swimming control group (SW, N=8), and swimming + creatine group (SWCr, N=8). Swimming rats have been trained
for 7 weeks with incremental intensity (6d/w), based on the overtraining swimming-model [2]. Loading dose of creatine
monohydrate is 2.0g/kg body weight for the first week, and 0.4g/kg next 6 weeks. All rats were killed 15 minutes after
the last exercise. Plasma SOD, GSH-Px, MDA and NO were tested. Data are analyzed with ANOVA method
Results
Compared to sedentary control group, the actitives of plasma SOD and GSH-Px in swimming rats decreased
significantly (P<0.01) while the contents of MDA and NO increased remarkably (P<0.01). In swimming rats with
creatine supplementation, the level of plasma SOD was evidently higher (P<0.01) while NO observably lower (P<0.01),
but no obvious change of plasma GSH-Px and MDA concentration have been observed (P>0.05), when compared with
swimming control group. See table 1 below.

Discussion/ Conclusions
It’s well known that free radicals metabolize actively during exercise. In swimming rats, the levels of plasma SOD and
GSH-Px decreased while MDA and NO increased obviously in the present study. Hong Jin[3] revealed that creatine
supplementation could markedly decrease lipid peroxidation level in mitochondria of muscles which possibly benefited
to delay exercise-induced fatigue in swimming rats. Our results indicate that creatine supplementation increases the
activity of plasma SOD of swimming rats while decreases the content of plasma NO, but does not change levels of
plasma GSH-Px and MDA. It is inferred that creatine could contribute to eliminate O2- and reduce the production of
OONO- during exercise but not reduce the level of lipid peroxidation. The possible antioxidant mechanism of creatine
supplementation during exercise is still not clear.

References
[1]. Lawler,JM, Barnes WS, Wu G, et al.(2002). Biochem Biophys Res Commun, 290(1):47-52.
[2]. Quan Zhu, Junzhong Pu (1998). Journa of China Sports Medicine, 17(2) :137-140.
[3]. Hong Jin, Zhiqin Xu, Xianyuan Wang, et al. (2002). Journa of China Sports Medicine, 21(1) :95-97

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