ABSTRACT
Objective:Dipeptidyl peptidase I(DPPI),a lysosomal cysteine protease for serine proteases activation,highly expressed in granule immune cells.This study used collagen induced arthritis(CIA) rat model to investigate the effects of Triperygium Wilfordii Polyglucoside(TWP) on DPPI activity and the pharmacological mechanism in RA treatment.Methods:Rats were divided into four groups randomly,the blank control group,the CIA model group,the high dose (5.0 mg/100 g body-weight) and low dose(2.5 mg/100 g body-weight)treatment group.Bovine collagen-Ⅱ plus complete Freund′s adjuvant injected twice in rats.Physical assessments were carried out.12 days post-injections,the rats of treatment group were intragastric administered with TWP every day.The rats were killed after two week administrations.Serum and synovial membrane homogenates were collected and DPPI activity was detected by fluorescence substrate.Joint HE staining and cell counting were carried out,Zymography was used to detect the MMP-2/9 activity in synovial fluids.Total protein in synovial membrane homogenates were measured by BCA method.Results:TWP could reduce the number of CIA synovial tissue mast cells,inhibited DPPI activity in the synovial fluids and in serum.The expression levels of MMP-2/9 activity and synovium total protein content were also reduced by TWP.Conclusion:Triperygium Wilfordii Polyglucoside has inhibitory effects on DPPI activity on CIA rats,which might be the one of the pharmacological mechanisms in RA treatment.