Abstract: Objective To study the effect of pinocembrin (Pb) on extracellular matrix (ECM) synthesis in angiotensin Ⅱ (AngⅡ)-induced rat mesangial cells and its mechanism. Methods Rat mesangial cells were divided into the following groups: normal control group (NC), 1×10 -6 mol/L AngⅡ group (Ng), 1×10-6 mol/L AngⅡ+1‰ DMSO group (Ng-D), 1×10-6mol/L AngⅡ+30 μmol/L Pb group (Ng-Pb) and 1×10-6 mol/L AngⅡ+10 μmol/L valsartan group (Ng-Val). Cells and supernatants were collected at 12, 24 and 48 hours after intervention. CollagenⅣ (ColⅣ),fibronectin(FN),transforming growth factor β1 (TGF-β1), Smad3, p-Smad3, nuclear factor kappa B (NF-κb) and p-NF-κb were detected by Western blot assay. The levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6)were detected by ELISA , and the RNA levels of Col Ⅳ, FN, TGF-β1, TNF-α and IL-6 were detected by qPCR.Results (1) The effect of Pb on synthesis of ECM in Ang Ⅱ-induced rat mesangial cells: after Ang Ⅱ stimulation, the protein and mRNA levels of ColⅣ and FN in rat mesangial cells were significantly increased(P＜0.05),and pre-stimulation with Pb could significantly reduce the protein and mRNA levels of ColⅣ and FN ( P＜0.05).(2) The effect of Pb on the TGF-β1 /Smad3pathway: AngⅡ increased the protein and mRNA levels of TGF - β1, and raised the level of p-Smad3 / smad3 (P＜0.05), while pre-stimulation with Pb could significantly reduce the protein and mRNA level of TGF - β1, and decrease the level of p-Smad3 / smad3 (P＜0.05). (3)Effects of Pb on NF-κB-mediated pro-inflammatory factor production: after AngⅡ stimulation, the level of p-NF-κB/NF-κB increased significantly, the protein and RNA levels of IL-6 and TNF -α increased significantly (P＜0.05).Prestimulation with Pb could significantly alleviate the above changes ( P＜0.05).Conclusion Pb may inhibit synthesis of ECM in AngⅡ-induced rat mesangial cells through inhibiting the TGF -β1 / Smad3 pathway and NF -κB-mediated proinflammatory factor production.

Key words: pinocembrin, angiotensin Ⅱ , extracellular matrix, transforming growth factor beta1, NF-kappa B, mesangial cells