Blueberry Extract Mitigates Inflammation and Fibrosis by Suppressing NF-κB and TGF-β in Kidney Nephropathy

Abstract

Background: Chronic kidney disease (CKD) is a global health issue marked by progressive inflammation and fibrosis. The unilateral ureteral obstruction (UUO) model is commonly used to study obstructive nephropathy, yet effective treatments targeting its underlying mechanisms are limited. Objectives: This study aimed to evaluate the renoprotective effects of blueberry (Vaccinium corymbosum) extract on inflammation and fibrosis markers in a murine model of UUO. Methods: Male Swiss Webster mice were divided into five groups: sham, UUO day 7, UUO + blueberry day 7, UUO day 14, and UUO + blueberry day 14. Blueberry extract (1500 mg/kg BW) was administered daily via oral gavage. UUO was induced by surgical ligation of the right ureter under anesthesia. Kidney tissues were examined macroscopically and histologically. Blood urea nitrogen (BUN) and creatinine levels, glomerulonephritis scores, and immunohistochemical expression of NF-κB and TGF-β were assessed. Results: UUO caused right kidney enlargement by day 7 and severe hydronephrosis by day 14, along with significantly higher glomerulonephritis scores and increased expression of NF-κB and TGF-β (P<0.05 vs the SC group). Blueberry extract administered for 7 or 14 days improved kidney structure, lowered glomerulonephritis scores (P=0.53 and P=0.87, respectively), and significantly reduced NF-κB and TGF-β levels (P<0.05 vs the UUO group). BUN and creatinine levels were slightly higher in the UUO groups but showed no significant difference (P>0.05 vs the SC group), with lower values in the treated groups. Conclusion: These findings suggest that blueberry extract may protect against UUO-induced obstructive nephropathy by reducing inflammation and fibrosis.