Effect of Asiaticoside on Expression of Th17/Treg Cells in DBA/1 Mice with Collagen-Induced Arthritis / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo observe the effect of asiaticoside （AC） on the expression of T helper 17 （Th17） cells and regulatory T （Treg） cells in DBA/1 mice with collagen-induced arthritis （CIA）. MethodMale SPF DBA/1 mice were randomized into six groups according to body weight： control group， CIA group， methotrexate group （MTX group， ip， 0.5 mg·kg-1）， and AC low-， medium-， and high-dose groups （ig， 5， 15， 45 mg·kg-1， respectively）. Modeling was performed in rats other than the control group. To be specific， they were immunized with bovine type Ⅱ collagen and complete Freund's adjuvant on the first day and with bovine type Ⅱ collagen and incomplete Freund's adjuvant on the 21st day. Administration began on the day of the second immunization， once a day for 28 days. On the 49th day， related tissues were collected. Then， hematoxylin-eosin （HE） staining was performed to observe the pathological changes of the joints. Immunohistochemical method was used to detect the expression of interleukin-17 （IL-17） and forkhead box protein-3 （FoxP3）， the markers of Th17 and Treg cells， respectively， immunofluorescence double staining the expression of IL-17 and FoxP3 in CD4+T cells of mouse joint tissue， and flow cytometry the proportions of Th17 and Treg cells in mouse lymph nodes. ResultCompared with the control group， CIA group demonstrated joint disorder， damage of articular cartilage and bone， severe bone erosion （P<0.01）， increase in stained CD4 and IL-17 and the integral absorbance （IA） （P<0.01）， decrease in stained FoxP3 and the IA （P<0.01）， rise of Th17/Treg ratio （P<0.01）， elevation of Th17 expression in mouse lymph nodes （P<0.01）， and reduction in Treg expression （P<0.01）. Compared with CIA group， MTX group and three AC groups showed normal joints， alleviated bone erosion and damage， intact and smooth joint surface， and decrease in stained IL-17 and IA （P<0.05， P<0.01）， and MTX group and AC medium-dose and high-dose groups registered decrease in stained CD4 and IA （P<0.01） and reduction in Th17/Treg ratio （P<0.05， P<0.01）. Moreover， AC medium-dose and high-dose groups showed rise in stained FoxP3 and IA （P<0.05， P<0.01）. In the lymph nodes of mice， decrease in expression of Th17 cells （P<0.05， P<0.01） and the increase in expression of Treg cells （P<0.05， P<0.01） were observed in all the three AC group. ConclusionAC can regulate Th17/Treg balance by inhibiting the expression of Th17 cells and promoting the expression of Treg cells in CIA mice.