[Sinoline inhibits NLRP3 and downstream inflammatory factors to alleviate the arthritis symptoms in adjuvant arthritis rats].

Objective To investigate the anti-inflammatory effects of sinoline on adjuvant arthritis (AA) rats and the changes of NOD like receptor pyrin-domain containing 3 (NLRP3). Methods Wistar rats were randomly divided into control group, AA model group, (100, 200, 400) mg/kg sinomenine group and 100 mg/kg Tripterygium wilfordii group, with 10 rats in each group. Except for the control group, AA model was established by Freund complete adjuvant. 12 days after modeling, control group and model group were given the same amount of normal saline, and other groups were given drugs by intragastric administration, once a day, for consecutive 16 days. Joint conditions of AA rats were evaluated by multiple arthritis and joint swelling. The level of NLRP3 protein in synovial tissues was detected by Western blot, and the expression and distribution of NLRP3 in synovial tissues were detected by immunohistochemical staining. Serum levels of interleukin-1β (IL-1β), IL-6 and tumor necrosis factor α (TNF-α) were detected by ELISA. Results Compared with the control group, multiple arthritis and joint swelling significantly increased in model group, while those significantly decreased in sinomenine treatment groups and Tripterygium wilfordii group. Decreased expression of NLRP3 protein in synovial tissue was observed, along with the significantly reduced levels of IL-1β, IL-6 and TNF-α in serum in sinoline treatment groups. Conclusion Sinolin can improve joint inflammation in AA rats by inhibiting NLRP3 and downstream inflammatory factors.