The effect of methylphenidate and aerobic exercise on male rats' liver enzymes

Methylphenidate (Ritalin) is used to treat attention deficit hyperactivity disorder. But taking it without prescription from a physician to increase athletic and academic performance is common. The purpose of this study was to determine the effects of methylphenidate and aerobic exercise on the function of rats' liver enzymes.

Samples of this study were 80 male Wistar rats with average weight of 228±15 gr which divided into eight groups of ten. Studied groups included control group, aerobic exercise sham, drug sham, aerobic exercise, 10 mg of drug, 30 mg of drug, aerobic exercise +10 mg and aerobic exercise +30 mg group. Drug groups and aerobic exercise + drug groups took drugs according to their weights orally. The physical activity (25 m/min) was performed 30 minutes a day, three days a week for two months for aerobic exercise and aerobic exercise + drug groups. After the last session of aerobic exercise, blood samples were taken from the rats, and also liver enzymes were measured. Statistical computations (ANOVA, Tukey) were performed for data analysis at the level of 0.05.

Statistical calculations among different groups showed that serum changes in liver enzymes in the aerobic exercise group were not significantly different from the control, aerobic, and sham groups. However, in the drug group and also in the exercise + drug group, the increased dose-dependent of serum in liver enzymes was significantly higher than the control, aerobic, drug sham, and aerobic training groups (p<0.05).

A dose-dependent increase in liver enzymes in the drug and exercise + drug groups, even in comparison to the aerobic exercise group, suggests a possible hepatotoxicity of non-therapeutic use of methylphenidate risk of non-therapeutic methylphenidate associated with aerobic exercise. Therefore, further research is needed to confirm and generalize these results.