Influence of supplemental quercetin and epigallocatechin 3‐gallate on immunity and inflammation

Abstract

Quercetin is a flavonol with broad spectrum bioactive effects that include anti‐inflammatory, anti‐pathogenic, antioxidant activity, and immunoregulatory influences. We tested the influence of 1000 mg quercetin (Q) with or without 120 mg epigallocatechin 3‐gallate (EGCG), 400 mg isoquercetin, and 400 mg EPA‐DHA (Q‐EGCG) on changes in measures of immunity and inflammation before and after a 3‐day period of heavy exertion. 39 trained cyclists were randomized to placebo, Q, or Q‐EGCG, and ingested supplements in a double blinded fashion for 2 weeks prior to, during, and 1 week after a 3‐d period in which subjects cycled for 3 h/d at 57% Wattsmax. Blood and saliva samples were collected before and after 2 weeks supplementation, immediately following the exercise bout on the 3rd day and 14‐h post‐exercise. Two weeks supplementation resulted in a significant increase in granulocyte oxidative burst activity (GOBA) in Q‐EGCG relative to P and increases in plasma quercetin for Q and Q‐EGCG. Immediately after the 3rd exercise bout, significant decreases for C‐reactive protein, plasma IL‐6 and IL‐10 were measured in Q‐EGCG compared to P. Granulocyte colony stimulating factor (GCSF) and CRP were reduced in Q‐EGCG 14‐h post‐exercise. Two weeks supplementation with Q‐EGCG was effective in augmenting GOBA, and countering inflammation following 3 days of heavy exertion in trained cyclists. Grant support from Quercegen Pharma.