Effects of pyrroloquinoline quinone (PQQ) supplementation on mitochondrial biogenesis, mitochondrial function and aerobic exercise performance in untrained men.

Endurance training enhances aerobic performance and improves mitochondrial biogenesis, function, and antioxidant capacity. Pyrroloquinoline quinone (PQQ) is a novel supplement involved in processes such as mitochondrial biogenesis, cellular energy metabolism, and redox modulation. Since endurance exercise and PQQ exhibit similar mechanisms for mitochondrial biogenesis, it is plausible that PQQ may have ergogenic value. Presently, there are no studies examining the effects of PQQ supplementation in conjunction with endurance exercise. Therefore, the purpose of this study was twofold: (1) To investigate the acute effects of PQQ supplementation with exercise on the expression of genes involved in mitochondrial biogenesis/function; (2) examine the effects of a 6-week endurance-training program on mitochondrial biogenesis/function, protein carbonyls, and aerobic performance in untrained males. Twenty-three sedentary males were randomized to consume 20mg/day of PQQ or placebo (PLC). Both groups followed a supervised 6-week endurance-training program. Genes indicative of mitochondrial biogenesis (PGC-1, Cardiolipin synthase (CLS), Citrate Synthase (CS)) and function (Cytochrome C-1 (CYC-1), Succinate dehydrogenase (SDH), and Cytochrome c oxidase (COX4/1)) were analyzed to assess the acute effects of PQQ supplementation with exercise. Markers for aerobic performance, mitochondrial biogenesis, function, and oxidative stress were measured after the 6-week endurance-training program. An acute dose of PQQ with exercise presented no meaningful differences in all genes of interest. There were no significant differences between groups in all aerobic performance variables after endurance-training (p > 0.05). However, there were significant improvements in VO2peak, ventilatory threshold percent at VO2peak, and total exercise test duration after endurance-training irrespective of group (p < 0.05). The PQQ group significantly increased PGC-1 protein levels after endurance-training (p < 0.05). There were no significant differences between groups in protein carbonyl content (p > 0.05). PQQ supplementation did not differentially improve Complex I, Complex III, Complex IV, and CS activity (p > 0.05). However, Complex I, Complex IV, and CS activity significantly improved irrespective of group after endurance-training (p < 0.05). Although PQQ supplementation presented no ergogenic improvements, the increases in PGC-1 protein content suggests mitochondrial adaptation. Further research is needed with variations in intensities and duration to ascertain if PQQ carries any ergogenic benefits with exercise.