Abstract: To explore the therapeutic effect and mechanism of total flavones of Abelmoschus manihot(TFA) on renal fibrosis in diabetic kidney disease,20 male SPFC57BLKS/J db/db mice were randomly divided into 4 groups,namely TFA lowdose group (97.5 mg/kg/d),TFA middledose group (195 mg/kg/d),TFA highdose group (390 mg/kg/d) and the model group.Five db/m mice in the same background were used as the blank control group.Mice were intragastrically administered with TFA’s suspension or an equal volume of 0.5% sodium carboxymethylcellulose solution for 16 weeks.At the 24th week mice were sacrificed and the blood and kidneys were collected.Urinary ACR,blood serum creatinine,and blood urea nitrogen were detected.HE staining and Masson staining were used to observe the changes of renal morphology and renal fibrosis.The expression of F4/80 in renal tissue macrophage was detected by immunohistochemical staining.The F4/80,collagen III and vimentin proteins in renal tissue were detected by Western Blot.The expressions of TNFα, IL1β and iNOS were detected by qPCR method.The results showed that:compared with the model group,TFA could reduce urinary ACR,serum creatinine,blood urea nitrogen,lighten the pathological damage and collagen fiber deposition of the kidney,decrease the expression of collagen III,vimentin and F4/80 proteins in mice renal tissues,reduce F4/80 labeled macrophage infiltration in renal tissue,and downregulate the mRNA expressions of TNFα, IL1β and iNOS in renal tissues.In summary,TFA can effectively alleviate inflammatory response in db/db mice,improve renal function and renal fibrosis,and play a role in renal protection.Its mechanism is related to inhibition of macrophage infiltration in renal tissues and proinflammatory M1 macrophage polarization.

Key words: total flavones of Abelmoschus manihot, renal fibrosis, macrophage, inflammation, db/db mice