Abstract:

This study aimed to investigate the effects of Capparis spinosa fruit (CSF) on gout in mice and its impact on gut microbiota. A hyperuricemia (HUA) injury model was established in C57BL/6 mice via intraperitoneal injection of potassium oxonate (300 mg/kg). The mice were divided into five groups (n = 10 per group): control, model, allopurinol, high-dose CSF (400 mg/kg), and low-dose CSF (200 mg/kg). Renal pathological changes were assessed using HE and Masson staining. Serum and urinary levels of uric acid (UA), creatinine (Cr), blood urea nitrogen (BUN), and xanthine oxidase (XOD). Inflammatory cytokines, such as interleukin-1β (IL-1β), IL-10, nuclear factor kappa B (NF-κB) were detected using ELISA kits. Cecal contents were collected for 16S rRNA high-throughput sequencing to analyze changes in the gut microbiota. Following treatment group intervention, pathological damage in renal tissue of model mice was significantly ameliorated, with no inflammatory cell infiltration observed in the renal interstitium and restoration of the brush border structure within renal tubules. Levels of UA, Cr, BUN, and XOD in both serum and urine were significantly reduced (P<0.01). The release of pro-inflammatory factors (IL-1β and NF-κB) was markedly suppressed, while the expression of the anti-inflammatory factor IL-10 was significantly increased (P<0.01). Significant alterations in the richness and diversity of gut microbiota were observed among the groups. Compared with the control, the model exhibited an increased abundance of Muribaculaceae, and decreased abundances of Prevotellaceae_UCG-003, Prevotella, and Bacteroides. After treatment with high-dose CSF, these microbial imbalances were effectively reversed. Correlation analysis revealed that the abundances of Muribaculaceae, Bacteroides, and Prevotella were significantly associated with HUA-related renal injury indicators (UA, Cr, BUN, XOD) and inflammatory factors (IL-1β, IL-10, NF-κB). Specifically, increased abundances of Muribaculaceae and Prevotella were associated with elevated levels of pro-inflammatory factors IL-1β and NF-κB, reduced expression of IL-10, and aggravated inflammatory injury in HUA. In contrast, an increased abundance of Bacteroides was associated with improved inflammatory status in HUA mice. In conclusion, CSF may ameliorate hyperuricemia by modulating immune inflammation and gut microecological disorders, potentially through regulating gut microbiota diversity and modifying the abundances of Muribaculaceae, Prevotella, and Bacteroides.

Key words: Capparis spinosa fruit, immuno-inflammation, gut microbiota, hyperuricemia