Therapeutic effect of rutin on Henoch-Schönlein purpura by attenuating inflammation and protection of the intestinal barrier function in rats.

Henoch-Schönlein purpura (HSP) or immunoglobulin A vasculitis (IgAV) is the most common systemic vasculitis in children. Rutin is a flavonoid with anti-inflammatory and antioxidant effects. This study aimed to investigate the protective effects of rutin in a rat model of HSP induced by ovalbumin. Results showed that 12.05 mg/kg of rutin significantly alleviated skin purpura, renal injury and systemic inflammation. It ameliorated vascular endothelial injury by reducing IgA deposition, modulating vasoactive substances including nitric oxide and endothelin-1, as well as vascular endothelial growth factor, and inhibiting the transforming growth factor-β1/SMAD family member 3 signaling pathway. These therapeutic effects were mediated through multiple mechanisms, including increasing the expression of zonula occludens-1 and occludin to maintain intestinal barrier integrity, modulating gut microbiota composition, and regulating the metabolism of short-chain fatty acids and amino acids. This study provides novel mechanistic insights and evidence supporting the clinical application of rutin in HSP.