The effect of propolis supplementation in improving antioxidant status: A systematic review and meta-analysis of controlled clinical trials

The present study aimed to assess the effect of propolis supplementation on oxidative status, a key contributor to the etiology of many chronic diseases. A systematic search of multiple databases, including Web of Science, SCOPUS, Embase, PubMed, and Google Scholar, was conducted from inception to October 2022 to identify articles examining the effect of propolis on glutathione (GSH), glutathione peroxidase (GPX), total antioxidant capacity (TAC), superoxide dismutase (SOD), and malondialdehyde (MDA) levels. The quality of the included studies was evaluated using the Cochrane Collaboration tool. A total of nine studies were included in the final analysis, and a random-effects model was used to pool the estimated effects. Results showed that propolis supplementation significantly increased the levels of GSH (SMD = 3.16; 95% CI: 1.15, 5.18; I = 97.2%), GPX (SMD = 0.56; 95% CI: 0.07, 1.05; p = 0.025; I = 62.3%), and TAC (SMD = 3.26; 95% CI: 0.89, 5.62; I = 97.8%, p