High versus Low doses of Anti-inflammatory Drugs Do Not Differentially Affect Muscle Molecular Response to Acute Resistance Exercise

Abstract

PURPOSE: We recently reported that high doses of non-steroidal anti-inflammatory drugs (NSAIDs) attenuate resistance exercise-induced muscle hypertrophy in young adults. Yet, little is known about the molecular mechanisms behind this effect. The current study aimed to examine acute muscle molecular responses to resistance exercise during co- ingestion of high and low doses of anti-inflammatory drugs. METHODS: Thirty one young (age 18-35 years) healthy men and women were randomly assigned to daily consumption of high doses of ibuprofen (IBU; 1200 mg; n=15) or low doses of acetylsalicylic acid (ASA; 75 mg; n=16) during an 8-week training intervention. During this period, subjects performed 20 supervised resistance training sessions (4 x 7-12 repetitions) involving the knee extensor muscles. Gene expression and protein signaling of key muscle growth regulators were analyzed from skeletal muscle biopsies obtained before training/treatment and 3 hours after an acute resistance exercise session during week 4 of the intervention. Real-time qPCR procedures were employed to determine mRNA expression. Protein signaling was assessed using western blots. RESULTS: Gene expression of myostatin (0.4-fold; p>0.0005), MuRF-1 (0.8-fold; p=0.015) and FoxO3 (0.6-fold; p>0.0005) decreased in response to the resistance exercise bout, with no difference across groups. Gene expression of IL-6 and STAT3 were unaltered. Protein phosphorylation of p70S6K increased (24-fold, P>0.0005) in response to the resistance exercise bout, with no difference across groups. Protein phosphorylation of STAT3 remained unchanged. CONCLUSIONS: These results show that high and low doses of NSAIDs do not differentially affect exercise-induced changes in gene expression and protein signaling for key markers of muscle growth in young adults. We therefore conclude that these acute markers do not seem to explain the negative effects of high doses of NSAIDs on muscle hypertrophy.