Ethanolic Blueberry Extract Inhibits Tubular Injury, Inflammation, and Oxidative Stress in a Mouse Model of Kidney Fibrosis

Background: Kidney fibrosis is a progressive condition characterized by tubular injury, inflammatory cell infiltration, and oxidative stress resulting from increased reactive oxygen species. The blueberry exhibits strong antioxidant and anti-inflammatory properties, rendering it a promising natural therapy for inhibiting kidney damage. This study aimed to evaluate the therapeutic effects of this extract on tubular injury scores, the number of inflammatory cells, interleukin-1 beta (IL-1β) expression, and malondialdehyde (MDA) levels in a Swiss Webster mouse model of kidney fibrosis. Methods: An experimental design was conducted using 25 male Swiss Webster mice, divided into five groups: a control group and four groups with unilateral ureteral obstruction (UUO), with or without blueberry extract therapy. The crude 70% ethanolic blueberry (Vaccinium corymbosum) extract was administered orally (1500 mg/kg body weight) via gavage for 7 or 14 days, followed by histological and biochemical analysis of the harvested kidneys. Results: UUO significantly increased tubular injury, inflammatory cell infiltration, IL-1β expression, and MDA levels compared to the control group. Mice treated with blueberry extract showed a 22–13% reduction in tubular injury scores, a 25–21% decrease in inflammatory cell counts, a 39–34% reduction in IL-1β expression, and a 7– 5% decline in MDA levels at 7 and 14 days, respectively. These therapeutic effects were attributed to the extract’s ability to suppress inflammation and inhibit lipid peroxidation triggered by oxidative stress. Conclusions: The crude ethanolic extract of Vaccinium corymbosum demonstrates significant potential as a natural therapeutic agent in reducing kidney damage, inflammation, and oxidative stress in kidney fibrosis.