[Quercetin ameliorates diabetic kidney injury in rats by inhibiting the HMGB1/RAGE/NF-κB signaling pathway].

Objective: To explore the effect of quercetin on renal inflammation and cell apoptosis in diabetic rats and its possible mechanisms.

Methods: Twenty-four adult male SD rats were randomized equally into normal control group, high-glucose and high-fat feeding group, streptozotocin (STZ) -induced diabetic model group, and quercetin treatment (daily dose 100 mg/kg) group. Pathological changes of the renal tissues of the rats were observed with HE staining, serum inflammatory factor levels were determined with ELISA, and renal expression of NF‑κB was observed by immunohistochemistry. Fast blood glucose (FBG), serum levels of triglyceride (TG), BUN, and Scr, and 24-h urine protein content of the rats were measured, and renal expressions of HMGB1, RAGE, NF‑κB, Bax, Bcl-2, and caspase-3 were detected with Western blotting.

Results: The diabetic rats showed significantly increased levels of FBG, TG, BUN, and Scr, renal hypertrophy index, 24-h urinary protein content, serum IL-1β, IL-6 and TNF-α levels and renal expressions HMGB1, RAGE, NF‑κB, Bax, and caspase-3 with decreased renal expression of Bcl-2. All these changes were significantly alleviated by quercetin treatment of the rats.

Conclusion: Quercetin can ameliorate kidney injury in diabetic rats possibly by inhibiting the HMGB1/RAGE/NF-κB inflammatory signaling pathway to reduce renal inflammation and renal cell apoptosis.