Concentration-Dependent Effect of Resveratrol on the Respiration of Rat Heart Mitochondria

Abstract

Background: Resveratrol is known to influence mitochondria both directly and indirectly. Its effects vary depending on the micromolar concentration used in in vitro or in vivo studies. At low concentrations, resveratrol exhibits antioxidant properties, whereas at higher concentrations, it possesses pro-oxidant activity. Aim: To assess the impact of resveratrol on the respiration rates of rat heart mitochondria utilizing substrates of respiratory complexes I and I+II. Methods: Mitochondria from rat hearts were isolated by differential centrifugation. Protein quantity was determined by the biuret method. The mitochondrial respiration rates were measured using the high-resolution respirometry system Oxygraph-2k. Results: Resveratrol at concentrations ranging from 10 to 150 µM had no significant effect on the leak state of mitochondria oxidizing pyruvate + malate (5 mM+2 mM) or succinate (10 mM). However, at higher concentrations (200–300 µM), resveratrol induced a statistically significant increase in the leak state rate when pyruvate+malate was used as a substrate. Additionally, the effect of resveratrol (50–150 µM) on the rate of oxidative phosphorylation (State 3) was examined. In mitochondria oxidizing pyruvate + malate, resveratrol inhibited the State 3 rate in a concentration-dependent manner, reducing it by 53% at 50 µM, 63% at 100 µM, and 73% at 150 µM. Conclusions: 1. Resveratrol at concentrations of 10–150 µM had no effect on the leak state respiration rate of rat heart mitochondria oxidizing substrates of complexes I and I+II. However, at higher concentrations (200–300 µM), resveratrol caused a statistically significant increase in the leak state respiration rate with substrates of complex I. 2. The effect of resveratrol on the State 3 respiration rate was concentration-dependent. While resveratrol at 10 µM and 25 µM had no statistically significant impact, higher concentrations (50–150 µM) significantly inhibited oxidative phosphorylation in rat heart mitochondria oxidizing substrates of complex I.