Background and Aim: Creatine supplementation is the most popular supplement used as an ergogenic and therapeutic aid. The purpose of this study was to examine the effect of creatine supplementation on apoptotic factors Bcl-2, Bax and Bcl-2/Bax ratio in middle-aged men during acute resistance exercise.

Material and Method: In a placebo-controlled, double-blind, randomized, parallel study, twenty seven men (mean age 45.59±5.43) were randomly assigned to 3 groups: supplement group (n=10) received 20 g of creatine monohydrate per day and placebo group (n=10) received maltodextrin for one week. Our control group included 7 men. On the 8^th day, the subjects in the experimental groups performed an acute resistance exercise with 80% of one repetition maximum. The controls did not perform any exercises. Blood samples were collected one day before supplement intake (Pre) and immediately after acute exercise (Post) for the measurement of serum Bcl-2 and Bax concentrations.

Results: Bcl-2 significantly increased by 118/78 percent in creatine group (p<0.05) and reduced by 7/36 percent in placebo group (p>0.05) in the Post compared to the Pre exercise stage. In the Post exercise stage, serum Bax protein concentration increased in the placebo group by 17/98 percent (p<0.05) but did not change in the creatine group in comparison to the Pre exercise stage (p>0.05). The alteration percent of Bcl-2/Bax ratio was significantly higher in the creatine group after exercise (p<0.05) whereas in the placebo group it was lower compared to the Pre exercise stage (p<0.05). No changes were detected in the control group. Conclusion: Based on the results of the study acute resistance exercise, caused apoptosis which was confirmed by increased Bax and decreased alternation percent of Bcl-2/Bax ratio in the placebo group, but creatine monohydrate can provide a protective effect against apoptosis by increasing Bcl-2 and Bcl-2/Bax ratio. Thus, use of creatine supplementation may be useful for prevention of apoptotic cell death induced by stress of acute intense exercise.

Key words: Creatine monohydrate, Bcl-2, Bcl-2/Bax ratio, Resistance exercise.

Received: May 7, 2016      Accepted: June 21, 2016