Effect of Flavonoids from Wang Zaizi on Adjuvant Arthritis in Rats and Its Mechanism

Objective The therapeutic effect and mechanism of total flavonoids in Isodon amethystoides (Ben-th) Cy Wu et Hsuan (TFIA) on adjuvant arthritis (AA) were investigated. Methods AA model rats were set and complete Freund’s adjuvant injection, randomly divided into 4 groups: AA group, AA+TFIA 50 mg/kg group, AA+TFIA 100 mg/kg group, AA+TFIA 150 mg/kg group, and each group has 10 rats. Blank control group was set without modeling (n=10). Four days post-modeling rats in each TFIA groups were treated once a day with TFIA at 50 mg/kg, 100 mg/kg and 150 mg/kg for 24 d, and rats in blank control and AA groups were given saline as control. At the 12th day, 16th day, 20th day and 24th day of treatment, the effect of TFIA on AA rats was evaluated by rat arthritis score. Then the rats were sacrificed on the 24th day of treatment, and the synovial tissue of rats was isolated and the fibroblast-like synoviocytes (FLS) were primary cultured. The expressions of IL-1 in FLS was detected by ELISA, the FLS proliferation activity was detected by MTT assay, and the expression of miR-152, β-catenin and cyclin D1 gene (ccnd1) were detected by real time qPCR. MiR-152 mimics and NC mimics (control) were transfected into FLS in AA rats, and miR-152 inhibitors and NC inhibitors (control) were transfected into FLS in AA+TFIA 100 mg/kg group rats. The expressions of miR-152, β-catenin,ccnd1,IL-1 and FLS proliferation were detected 36 h post-transfection. Results TFIA significantly inhibited the arthritis socre of rats and the expressions of β-catenin,ccnd1,IL-1 and the proliferation of FLS in AA rats (P<0.05). There was no significant difference between the dose groups, all of which were significant when compared with the blank control group (P<0.05). Compared with the control group, the expression of miR-152 in AA group was significantly decreased (P<0.05). After transfection of miR-152 mimics into AA FLS, overexpression of miR-152 significantly inhibited the expressions of β-catenin,ccnd1,IL-1 and the proliferation of FLS (P<0.05). After transfection of miR-152 inhibitors into FLS from AA+TFIA 100 mg/kg group, inhibition of miR-152 significantly promoted the expressions of β-catenin,ccnd1,IL-1 and the proliferation of FLS. Conclusion TFIA has a certain therapeutic effect on AA rats via the up-regulation of miR-152 expression, possibly affecting the classical Wnt signaling pathway.