Vitamin E supplementation decreases muscular and oxidative damage but not inflammatory response induced by eccentric contraction

Abstract

The purpose of this study was to investigate the effects of vitamin E supplementation on muscular and oxidative damage, as well as the inflammatory response induced by eccentric exercise (EE) in humans. Twenty-one participants with a mean age of 22.5 +/- 4 years, weight of 68.2 +/- 4.9 kg, and height of 173 +/- 4.3 cm were selected and divided randomly into two groups: supplemented (S) (n = 11) and placebo (P) (n = 10). Fourteen days after starting supplementation, subjects performed EE (three sets until exhaustion with elbow flexion and extension on the Scott bench, 80% 1 RM). Blood samples were collected on days 0, 2, 4, and 7 after EE. Muscle soreness (MS), lactate dehydrogenase (LDH) activity, lipid peroxidation, protein carbonylation, tumor necrosis factor-alpha (TNF-alpha), and interleukin 10 (IL-10) levels were determined. We measured a significant increase in MS, LDH, lipid peroxidation, and carbonylation in both groups on days 2, 4, and 7 after eccentric contractions (EC). Values of the supplement group were lower than those of the placebo group at 4 and 7 days after EC in all parameters. Both groups showed significantly increased TNF-alpha on the second day and IL-10 concentration on the fourth and seventh days after EE. The results suggest that vitamin E supplementation represents an important factor in the defense against oxidative stress and muscle damage but not against the inflammatory response in humans.

Fig. 1

Serum lipid peroxidation levels in the serum of young university students before (pre-EE) and 2, 4, and 7 days after the eccentric exercise for subjects provided vitamin E supplement or placebo. The values are presented as mean ± SEM and the results expressed in TBARS level (nmol/mg of protein). The difference in relation to pre-EE (asterisk) and to placebo group (hash symbol) was significant at p < 0.05

Fig. 2

Serum protein carbonyl levels in the serum of young university students before (pre-EE) and 2, 4, and 7 days after the eccentric exercise for subjects provided vitamin E supplement or placebo. The values are presented as mean ± SEM, and the results expressed in nmol/mg of protein. The difference in relation to pre-EE (asterisk) and in relation to placebo group (hash symbol) was significant at p < 0.05

Fig. 3

Serum tumor-necrosis factor-α (TNF-α) levels in the serum of young university students before (pre-EE) and 2, 4, and 7 days after the eccentric exercise for subjects provided vitamin E supplement or placebo. The values are presented as mean ± SEM and the results expressed in pg/ml of serum. The difference in relation to pre-EE (asterisk) was significant at p < 0.05

Fig. 4

Interleukin 10 (IL-10) in the serum of young university students before (pre-EE) and 2, 4, and 7 days after the eccentric exercise for subjects provided vitamin E supplement or placebo. The values are presented as mean ± SEM and the results expressed in pg/ml of serum. The difference in relation to pre-EE (asterisk) was significant at p < 0.05