Effects of Propolis supplementation on inflammation and oxidative stress markers: A GRADE-assessed systematic review and Meta-analysis of clinical trials

This systematic review and meta-analysis evaluated propolis supplementation effects on inflammatory and oxidative stress markers in adults. Analyzing 41 randomized controlled trials with 2212 participants through July 2025, the study examined inflammatory markers (CRP, hs-CRP, TNF-α, IL-2, IL-6, IL-8, IL-10, IL-1β) and oxidative stress parameters (MDA, SOD, TAC, GSH, GPx, PAB). Results showed significant reductions in inflammatory markers: hs-CRP (WMD: −0.72 mg/L; 95 % CI: −1.27 to −0.17; P = 0.017), TNF-α (WMD: −0.95 pg/mL; 95 % CI: −1.53 to −0.37; P = 0.001), and IL-6 (WMD: −1.16 pg/mL; 95 % CI: −1.96 to −0.36; P = 0.005). For oxidative stress, propolis significantly improved SOD (SMD: 1.91; 95 % CI: 0.91 to 2.91; P < 0.001), TAC (SMD: 3.12; 95 % CI: 0.81 to 5.44; P = 0.008), GSH (SMD: 3.891; 95 % CI: 1.749 to 6.032; P < 0.001), and GPx (SMD: 0.64; 95 % CI: 0.22 to 1.07; P = 0.003). These findings suggest propolis may serve as a promising natural intervention for inflammatory and oxidative imbalances. Highlights • Meta-analysis of 41 RCTs showed propolis reduced hs-CRP, TNF-α, and IL-6 inflammatory markers significantly. • Propolis enhanced antioxidant systems by increasing SOD, TAC, GSH, and GPx levels in supplemented groups. • Males showed greater CRP and IL-6 reductions; females demonstrated better hs-CRP reduction and SOD enhancement. • Doses >500 mg/day provided superior anti-inflammatory benefits for TNF-α and IL-6 reduction (dose-dependent).