Betulin from Hedyotis hedyotidea ameliorates concanavalin A-induced and T cell-mediated autoimmune hepatitis in mice  

作　　者：Yong-qin ZHOU Xiu-fang WENG Rui DOU Xiao-sheng TAN Tian-tian ZHANG Jin-bo FANG Xiong-wen WU 

机构地区：[1]Department of Immunology, Tongli Medical College, Huazhong University of Science and Technology, Wuhan 430030, China [2]Department of Immunology, Medical College, China Three Gorges University, Yichang 443002, China [3]School of Pharmacy, Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China

出　　处：《Acta Pharmacologica Sinica》2017年第2期201-210,共10页中国药理学报（英文版）

基　　金：The authors would like to thank the NIH tetramer core facil- ity for the CDld tetramers, Dr Qin YANG of the Institute of Pathology, Tongji Hospital, Huazhong University of Science and Technology, and Senior Engineer Yaqin Wang and Asso- ciate Prof Xia WEI of the Department of Histology and Embry- ology, Medical College of China Three Gorges University for their help and technical assistance in histological examination. This work was supported by the National Natural Science Foundation of China （No 31370885, 31000150, and 81302528） and the 973 Program from the Ministry of Science and Tech- nology of China （No 2013CB530505）.

摘　　要：Hedyotis hedyotidea has been used in traditional Chinese medicine for the treatment of autoimmune diseases. However, the mechanisms underlying for the effect remain unknown. We previously showed that, among 11 compounds extracted from H hedyotidea, betulin produced the strongest suppressive effect on T cell activation. Here, we examined the hepatoprotective effects of betulin against acute autoimmune hepatitis in mice and the mechanisms underlying the effects. Freshly isolated mouse splenocytes were stimulated with concanavalin A （Con A, 5 pg/mL） in the presence of betulin, the cell proliferation was assessed with CSFE-dilution assay. Mice were injected with betulin （10, 20 mg.kg-1.d-1, ip） for 3 d. One hour after the last injection, the mice were injected with Con A （15 mg/kg, iv） to induce acute hepatitis. Blood samples and liver tissues were harvested at 10 h after Con A injection, and serum transaminase levels and liver histopathology were detected; serum levels of proinflammatory cytokines, hepatic T lymphocyte ratios, and functional statuses of conventional T and NKT cells were also analyzed. Betulin （16 and 32 μmol/L） dose-dependently suppressed the proliferation of Con A-stimulated mouse splenocytes in vitro. In Con A-challenged mice, preinjection with betulin （20 mg.kg-1.d-1） significantly decreased the levels of proinflammatory cytokines IFN-γ, TNF-α and IL-6, and ameliorated liver injury. Furthermore, pretreatment with betulin （20 mg-kg-1.d-1） significantly inhibited the Con A-induced activation of NKT and conventional T cells, and decreased production of proinflammatory cytokines IFN-γ, TNF-α and IL-6 in these two cell populations. Betulin has immunornodulatory effect on overly activated conventional T and NKT cells and exerts hepatoprotective action in mouse autoimmune hepatitis. The findings provide evidence for the use of H hedyotidea and its constituent betulin in the treatment of autoimmune diseases.Hedyotis hedyotidea has been used in traditional Chinese medicine for the treatment of autoimmune diseases. However, the mechanisms underlying for the effect remain unknown. We previously showed that, among 11 compounds extracted from H hedyotidea, betulin produced the strongest suppressive effect on T cell activation. Here, we examined the hepatoprotective effects of betulin against acute autoimmune hepatitis in mice and the mechanisms underlying the effects. Freshly isolated mouse splenocytes were stimulated with concanavalin A （Con A, 5 pg/mL） in the presence of betulin, the cell proliferation was assessed with CSFE-dilution assay. Mice were injected with betulin （10, 20 mg.kg-1.d-1, ip） for 3 d. One hour after the last injection, the mice were injected with Con A （15 mg/kg, iv） to induce acute hepatitis. Blood samples and liver tissues were harvested at 10 h after Con A injection, and serum transaminase levels and liver histopathology were detected; serum levels of proinflammatory cytokines, hepatic T lymphocyte ratios, and functional statuses of conventional T and NKT cells were also analyzed. Betulin （16 and 32 μmol/L） dose-dependently suppressed the proliferation of Con A-stimulated mouse splenocytes in vitro. In Con A-challenged mice, preinjection with betulin （20 mg.kg-1.d-1） significantly decreased the levels of proinflammatory cytokines IFN-γ, TNF-α and IL-6, and ameliorated liver injury. Furthermore, pretreatment with betulin （20 mg-kg-1.d-1） significantly inhibited the Con A-induced activation of NKT and conventional T cells, and decreased production of proinflammatory cytokines IFN-γ, TNF-α and IL-6 in these two cell populations. Betulin has immunornodulatory effect on overly activated conventional T and NKT cells and exerts hepatoprotective action in mouse autoimmune hepatitis. The findings provide evidence for the use of H hedyotidea and its constituent betulin in the treatment of autoimmune diseases.

关 键 词：Hedyotis hedyotidea BETULIN concanavalin A autoimmune hepatitis SPLENOCYTES NKT conventional T cells CYTOKINES hepatoprotective effects 

分 类 号：S858[农业科学—临床兽医学] Q2[农业科学—兽医学]