Verbascoside alleviates renal fibrosis in unilateral ureteral obstruction rats by inhibiting macrophage infiltration

Y Objective(s): To explore the effect of verbascoside on renal fibrosis in unilateral ureteral obstruction (UUO) rats. Materials and Methods: Twenty Sprague-Dawley rats were randomly distributed into sham-operated, UUO, and UUO+Verbascoside groups. After two weeks of rat model construction, urine and blood samples were collected for biochemical analysis while kidney tissues were harvested for hematoxylin and eosin (H&E), Masson's Trichrome, and immunohistochemistry staining. Pearson coefficient was used to analyze the correlation between the two proteins. Results: Verbascoside improved UUO-induced renal dysfunction as detected by decreased serum creatinine, urea nitrogen, and urinary protein excretion rate. In UUO rats, H&E staining result revealed increased total nucleated cell number, and Masson's Trichrome staining results showed tubular interstitial fibrosis with the deposition of collagen fibrils. Besides, expressions of fibrosis-related proteins including collagen type I (COL-I), alpha-smooth muscle actin (a-SMA), and tissue inhibitor of metalloproteinase 2 (TIMP2) expressed higher in the UUO group. Moreover, macrophage infiltrationrelated factors such as CD68+, F4/80+ cells, and suppressor of cytokine signaling-3 (SOCS3) were significantly higher in the UUO group than in sham-operated rats. However, after administration with verbascoside, the accumulation of collagen fibrils and total nucleated cell numbers were mitigated. Likewise, macrophage infiltration was extenuated and fibrosis-related proteins were down-regulated in the UUO+Verbascoside rats. Correlation analysis indicated that macrophage infiltration-related markers were related to fibrosis-related factors. Conclusion: Verbascoside could alleviate renal fibrosis in UUO rats probably through ameliorating macrophage infiltration.