Oridonin attenuates diabetes‑induced renal fibrosis via the inhibition of TXNIP/NLRP3 and NF‑κB pathways by activating PPARγ in rats

Introduction: Oridonin possesses remarkable anti-inflammatory, immunoregulatory properties. However, the renoprotective effects of Oridonin and the underlying molecular mechanisms have not been explored in Diabetic Nephropathy (DN). We hypothesized that Oridonin could ameliorate diabetes‑induced renal fibrosis. Methods: We used streptozocin (STZ)-induced diabetic rats combined high-fat diet to establish a type 2 diabetes mellitus (T2DM) animal model, and then treated with Oridonin (10,20mg/kg/day) for two weeks. Kidney function and renal fibrosis were assessed. We also treated high glucose-induced human renal proximal tubule epithelial cells (HK-2) with Oridonin. In addition, the expression of inflammatory factors and fibrotic markers were analyzed. Results: Oridonin treatment preserved kidney function and markedly limited the renal fibrosis size in diabetic rats. The renal fibrotic markers were inhibited in the 10mg/kg/day group and 20mg/kg/day group compared to the T2DM group. Moreover, the expression levels of TXNIP/NLRP3 and NF‑κB pathway were decreased and the level of PPARγ were increased in the Oridonin treatment group compared to non-treated group. In vitro, intervention of PPARγ could significantly regulate the effect of Oridonin on the high glucose-induced inflammatory changes in HK-2. Conclusion: Oridonin reduces renal fibrosis and preserves kidney function via the inhibition of TXNIP/NLRP3 and NF‑κB pathway by activating PPARγ in T2DM rat model, which indicates potential therapeutic effect of Oridonin on DN.