Objective To investigate the therapeutic mechanism of Pterocarya hupehensis Skan total flavonoids(PHSTF)for rheumatoid arthritis(RA).Methods Twenty-five male SD rats were randomly divided into normal control group,RA model group,PHSTF treatment(45 and 90 mg/kg)groups,and Tripterygium glycosides(TPG)tablet(10 mg/kg)group(n=5).Except for those in the normal control group,all the rats were subjected to collagen-induced arthritis(CIA)modeling using a secondary immunization method,after which PHSTF and TPG were administered via gavage once daily for 4 weeks.After the treatments,serum levels of TNF-α and IL-1β were measured using ELISA,and ankle joint pathologies were assessed with HE staining;the expression of citrullinated histone H3(Cit-H3),a neutrophil extracellular trap(NET)marker,in the ankle joints was evaluated with immunohistochemistry.In primary cultures of rat peripheral blood neutrophils stimulated with phorbol ester(PMA),the effects of PHSTF(100 and 200 μg/mL)on the expressions of Cit-H3,peptidylarginine deiminase 4(PADI4),neutrophil elastase(NE),and myeloperoxidase(MPO)were examined with Western blotting;immunofluorescence assay was used to observe Cit-H3 expression and NET formation in the cells.Results In the CIA rat models,PHSTF significantly alleviated ankle swelling,decreased serum levels of TNF-α and IL-1β,improved histopathological changes in the ankle joints,and reduced Cit-H3 expression in both the serum and ankle joint cartilage.In the isolated rat neutrophils,PHSTF showed no significant effect on cell viability but strongly inhibited PMA-induced NET release.Conclusion PHSTF can alleviate RA by inhibiting the formation of NETs.
关键词
枫杨总黄酮/中性粒细胞胞外陷阱网/类风湿关节炎
Key words
Pterocarya hupehensis Skan total flavonoids/neutrophil extracellular traps/rheumatoid arthritis