Effects of caffeine on brain L-arginine metabolism in rats

In our study, effects of caffeine on L- arginine metabolism in short-term and orally giventwo different doses of caffeine as 30 mg/kg and 100 mg/kg (high non-toxic dose) in rat brain wereinvestigated. Brain tissue arginase activity in caffeine groups decreased significantly compared bythe control group. There was no statistically significant change in the arginase activities betweenthe caffeine groups.The MDA levels of brain tissue and serum in the caffeine groups decreased significantlycompared by the control group. There was a statistically significant decrease in tissue MDA levelsbetween 30 mg/kg and 100 mg/kg dose caffeine groups. But there was no statistical significancybetween the changes in serum MDA levels of caffeine groups.Brain tissue and serum NO levels increased significantly with caffeine administrationThere was no statistical significancy in the change of NO levels between brain tissue and serum ofcaffeine groups.TNF-α levels were also investigated in rat serum. There was no statistical significancy inthe difference of TNF-α levels between caffeine groups and control groupIn conclusion; our study indicates that brain arginase activity decreases with 30 mg/kgdose and 100 mg/kg dose of caffeine administrations. Arginase activity decreases with caffeineadministration and arginine levels increase with decreased arginase activity. As a result, we cansay that arginine induces to produce NO in the organism. Our findings provide strong evidencesfor possible antioxidant effects of caffeine.