Figure 2: Quercetin reduces pro-inflammatory cytokine levels in the retina of a STZ-induced diabetic rat. (A–D) IL-1β (A), IL-18 (B), IL-6 (C), and TNF-α (D). Data are expressed as the mean ± SD (n = 10). *P < 0.05, **P < 0.01 (one-way analysis of variance followed by the Kruskal-Wallis test for multiple comparison). IL: Interleukin; Q; quercetin; STZ; streptozocin; TNF-α: tumor necrosis factor α; Znpp: zinc protoporphyrin IX.