Effects of resveratrol, catechin and epicatechin on rat phrenic nerve hemi-diaphragm

Aim: Resveratrol, catechin and epicatechin are known for their preventive effects of skeletal muscle atrophy, anti-fatique effects and enhancement of exercise capacity. In this study, we investigate the effects these antioxidants on muscle contraction by using rat phrenic nerve hemi-diaphragm preparations. Methods: Twitch responses are investigated by giving direct and indirect and tetanic stimulation to rat phrenic nerve hemi-diaphragm preparations. Results: Resveratrol and catechin facilitated twitch responses to the indirect stimulus in short duration and suppressed in long duration. The decrease in the responses to the direct stimulation by applying epicatechin (p=0.010) was significantly higher than the responses by giving indirect stimulation. Epicatechin significantly suppressed tetanic responses (p=0.005), but not resveratrol and catechin. Conclusion: The results of the study show that these antioxidants have presynaptic and postsynaptic effects on neuromuscular junction. Resveratrol effective on muscle contraction via direct stimulus, catechin and epicatechin effects muscle contraction by direct and indirect stimulus