ABSTRACT
Our previous experiments have shown that exercise increases cyclic Adenosine Monophosphate (cAMP) levels followed by activated Protein Kinase A (PKA) and the downstream target of PKA including phosphorylation of LKB-1 and CREB. The purpose of the present study was to examine whether the effect of the PKA inhibitor H89 abolishes the effect of curcumin on the regulation of mitochondrial biogenesis. Male Wistar rats aged 8 weeks were randomized into two groups: exercise group and non-exercise group. They were further divided into the following groups: Control group (DMSO), curcumin group (100 mg/kg-BW/day), H89 group (20 mg/kg-BW/day), and curcumin + H89 group (intraperitoneally injected for 3 days). The exercise regimen was swimming for 2 hours/day for 3 days. Western Blot (WB) and Immunoprecipitation (IP) analyses were carried out to assess protein and enzyme activities. We found that the administration of curcumin alone and in combination with exercise increased the phosphorylation of LKB-1, CREB, and COX-IV expression. However, interestingly, H89 abolished these effects. The present results indicate that inhibition of cAMP synthesis abolishes the impact of curcumin administration in the skeletal muscle of rodents.
