甘草黄酮对小鼠急性肺损伤保护机制的研究

为了研究甘草黄酮对非特异性肺部损伤小鼠的预防和治疗作用，采用脂多糖(LPS)滴鼻法建立了小鼠急性肺损伤模型。分别于造模前1 h和造模后1 h给予甘草黄酮(30 mg/kg)。在LPS滴入后6、12、24 h检测支气管肺泡灌洗液BALF中的细胞因子水平；测定肺组织湿干重(W/D)比率，观察肺部组织学的病理变化；并用Western-blot方法检测NF-κB水平变化。结果表明：甘草黄酮可以显著降低肺组织的W/D比率，减轻肺组织中炎性细胞的浸润，抑制肿瘤坏死因子α (TNF-α)、白细胞介素6(IL-6)和白细胞介素1β(IL-1β)等炎性细胞因子的产生，而且治疗的效果要优于预防的效果。Western结果显示：甘草黄酮可以显著抑制IκB的降解以及NF-κB向核内的转移，从而抑制了LPS下游的常见通路，即NF-κB信号通路，由此我们得出结论，甘草黄酮对LPS诱导的ALI小鼠具有保护作用，其治疗效果要好于预防效果，同时其保护机制与NF-κB信号通路的抑制相关。

The Protection Mechanism of Licorice Flavonoids on Acute Lung Injury in Mice

To study the preventive and therapeutic effects of licorice flavonoids on nonspecific lung injury in mice.We established the mouse model of acute lung injury by nasal instillation of lipopolysaccharide（LPS）.Mice were treated with licorice flavonoids at dosages of 30 mg/kg before or after LPS nasal instillation.At 6,12,24 h after LPS nasal instillation,cytokine level detection,pathological examination,the lung wet/dry weight ratio and the activity changes of NF-κB were performed.The results showed that licorice flavonoids displayed significantly anti-inflammatory in the lung tissue by reduce W/D ratios,attenuated inflammatory cell infiltration and suppress TNF-α,IL-6 and IL-1β expression levels.In addition,the treatment effect of licorice flavonoids was better than prophylaxis effect.Licorice flavonoids could also inhibited the degradation of I κB and the transfer of NF κB to nuclear.Thus licorice flavonoids could inhibited common LPS downstream channel that was NF-κB.Therefore,We suggested that licorice flavonoids effectively attenuate LPS-induced pulmonary inflammation through inhibition of NF κB pathway,and treatment effect of licorice flavonoids was better than prophylaxis effect.