Protective Effects Of Apigenin On The Concanavalin A-induced Autoimmune Hepatitis Mice Model

Aim:To study the influence of Apigenin(AP) on the biological behaviour of both T cells and RAW264.7 cells,and the therapeutic efficacy of AP to autoimmune hepatitis(AIH),in order to supply theory for developing new immunosuppressive drugs.Methods:The effects of AP on the activation, proliferation and cell cycle of T cells in response to Con A were measured by two-color fluorescent antibody,CFDA-SE and PI combined with flow cytometry;the apoptosis of T cells induced by DEX was measured by Annexin V-FITC/PI combined with flow cytometry.The effects of AP on the proliferation,NO secretion and phagocytosis of RAW264.7 cells in response to LPS were measured by MTT method, Griess kit and fluorescent microbeads.To found a steady mouse model of AIH on the base on ALT and liver histological section,and to investigate the therapeutic efficacy of AP on AIH according to above indexes.The effects of AP on the proliferation ofT cells in vivo was measured by injecting T cells dyed by CFDA-SE.Rusults:AP(25～200μmol/L) inhibits the expression of CD69,CD25 and CD71 on T cells in response to Con A,and inhibits the proliferation arresting cell cycle at G₀/G₁ and apoptosis of T cells significantly in a dose-dependent manner(P＜0.01).AP(25～200μmol/L) inhibits the proliferation,NO secretion and phagocytosis of RAW264.7 cells in response to LPS significantly in a dose-dependent manner(P＜0.01).ALT starts to heighten after 2 h injecting Con A by i.v.,and reaches peak value at 8 h exceeding the normal value significantly(P＜0.01).The liver histological section shows that the apoptosis and inflammatory cells infiltration get worse in a time-dependent manner, and significant at 8h.ALT value is higher than normal value after injecting 50mg/Kg AP for 8 times,but 100mg/Kg AP for 6～8 times or 200mg/Kg AP for 4～6 times can decrease ALT value to normal value without statistical difference with CsA ground(P＜0.01).Control ground has only one parent peak at 48 h showing T cells are still in vivo,Con A ground has 4 off-spring peaks showing T cells generate 4 times in vivo. CsA inhibits T cells proliferation in vivo significantly showing only one off-spring peak.100mg/Kg and 200mg/Kg AP ground have 2～3 off-spring peaks,and have statistical difference with Con A ground(P＜0.01).Conclusion:AP not only inhibits the activation,proliferation arresting cell cycle at G₀/G₁ in response to Con A and apoptosis of T cells in response to DEX,but also inhibits the proliferation,NO secretion and phagocytosis of RAW264.7 cells in response to LPS,showing AP has the potency of inhibition of adaptive immunological system and innative immunological system.Even,AP can cute AIH and inhibit the proliferation ofT cells in vivo.