Pyrroloquinoline Quinone (PQQ) and Indicators of Antioxidant Potential, Inflammation and Metabolism in Humans

Pyrroloquinoline quinone (PQQ) improves parameters related to energy metabolism in animals, which involve interactions with cell signaling important to mitochondrial function. However, little is known about responses to PQQ in humans. Using a crossover study design, 10 subjects ingested PQQ and were examined in two studies at 2 to 3 daily intervals. Plasma antioxidant potential (TBARS and TRAP measurements), inflammation (plasma C‐reactive protein and IL‐6), and standard clinical indices were measured, including urinary metabolites. In addition, PQQ clearance was investigated. Data suggested that PQQ is absorbed in the upper intestine with a relatively slow clearance from the plasma pool. Measurement of plasma antioxidant activity was highly correlated with plasma PQQ concentrations. Decreased levels of plasma C‐reactive protein and IL‐6 were also observed (~ 20 mg PQQ/day X 3 d; p <0.01). No changes in clinical indices were observed. However, exposure to PQQ (10–20 mg PQQ/day X 3 d) altered the distribution of mitochondrial‐related urinary metabolites in urine using as assessed by the NMR. It was concluded that the effects of PQQ in humans could be observed with a short‐term exposure at levels easily obtained in commercial supplements. Supported by Mitsubishi Gas and Chemical Co. and the Center for Health Related Research at UCD.