The Effect Of Ursolic Acid On Arthritis In CIA Rats And The Regulation Of Th17/Treg Cell Imbalance In Peripheral Blood

Objective:1.To investigate the effects of ursolic acid(UA)on joint swelling volume,arthritis index(AI)and joint X-ray score in collagen-induced arthritis(CIA)rats.2.To investigate the effect of UA on the imbalance of Th17/Treg cells in peripheral blood of CIA rats.Methods:Female Sprague-Dawley(SD)rats were selected to replicate the CIA rat model.After successful modeling,rats were randomly divided into CIA model group,UA low dose group,UA high dose group,methotrexate(MTX)group,UA + MTX group and treated accordingly.The changes of joint swelling volume and AI score were measured every 3 days from the 12 th day of the first immunization.At the 21 th day of the first immunization,peripheral blood lymphocytes were collected and stained.The ratio of Th17/Treg cells in peripheral blood was detected by flow cytometry.At the30 th day of the first immunization,the rats were killed for joint X-ray photography.Results:1.The percentage of Th17 cells in each group(%): Compared with the blank group,the percentage of Th17 cells in CIA model group increased significantly(P<0.01).Compared with CIA model group,UA high dose group,MTX group and UA+MTX group decreased significantly(P<0.01);compared with MTX group,UA low dose group and UA high dose group increased(P<0.01).2.The percentage of Treg cells in each group(%): Compared with the blank group,the percentage of Treg cells in CIA model group was significantly lower(P<0.01).Compared with CIA model group,UA high dose group and MTX group increased significantly(P<0.05),UA+MTX group increased significantly(P< 0.01).Compared with MTX group,UA+MTX group increased(P< 0.05).3.The swelling volume and AI index of the joints of the rats in each group reached the peak at 18-21 days after the first immunization.Compared with the blank group,the joint swelling volume and AI index in CIA model group decreased significantly (P< 0.01);compared with the CIA model group,the joint swelling volume and AI index in each treatment group decreased(P< 0.05)or(P< 0.01);and compared with MTX group,the swelling volume and AI index in UA+MTX group decreased(P<0.05).4.Compared with CIA model group,the X-ray scores of UA high dose group,MTX group and UA+MTX group decreased(P< 0.05)or(P< 0.01).Conclusion:UA can alleviate arthritis in experimental CIA rats,and its mechanism may be related to the regulation of Th17/Treg cell balance in peripheral blood.