Role Of Glycyrrhizic Acid In Acute Lung Injury Induced By LPS

Objective:To investigate the possible role of glycyrrhizic acid(GA)on LPS induced TNF-?,IL-1? production in RAW264.7 cells and to discover the role of GA on LPS induced acute lung injury(ALI).Methods:RAW264.7 cells were pretreated by GA(50,100,200 ?g/mL)or DMSO for 1h,then treated with LPS(1 ?g/mL)or PBS for 30 min or 6 h.The protein levels of IL-1?,TNF-?,I?B-?,NF-?B p65 were detected by western blot and I?B-?,NF-?B p65 levels were observed by immunofluorescence.Balb/c mice were randomly divided into four groups:Control group(DMSO+PBS),GA group(GA+PBS),LPS group(DMSO+10mg/kg LPS),GA(200 mg/kg)+LPS(10 mg/kg)group.Pretreated(i.p.)with GA or DMSO for 1 h,and then treated with LPS or PBS for 8 h.The lung tissues were collected and weighted.Hematoxylin-and-eosin(HE)staining was used to indicate the pathological damage in the lung of mice and lung coefficient was cacullated to evaluate the edema of lung.The protein levels of IL-1?,COX-2,MCP-1 and HMGB1 in the lung tissues were detected by immunohistochemisty and western blot,the expression of cav-1 and the ratio of I?B-?,NF-?B p65 phosphorylation of lung tissues were detected by western blot.Results:1.GA could decrease the production of TNF-a and IL-1? induced by LPS in RAW264.7 cells;2.GA could increase the production of I?B-? and inhibit the activation of NF-?B p65 in RAW264.7 cells;3.GA could alleviate lung injury;4.GA could decrease the production of IL-1?,COX-2,MCP-1and HMGB1 induced by LPS in lung tissues of ALI mice;5.GA could decrease the production of cav-1 and decrease the ratio of I?B-?,NF-?B p65 phosphorylation.Conclusions:1.GA could decrease the production of TNF-? and IL-1? in RAW264.7 cells induced by LPS via inhibiting the activation of NF-?B signaling pathway;2.GA could alleviate ALI induced by LPS and decrease the production of IL-1?,COX-2,MCP-1 and HMGB1 by inhibiting the activation of cav-1/NF-?B signaling pathway.