Experimental protocol for acute lung injury model

All rats were randomly divided into 8 groups and each group contained 8 rats: a control group (saline), a GLA group, 3 LPS groups (6 h, 12 h, 24 h), 3 LPS+GLA groups (6 h, 12 h, 24 h). LPS (10 mg/kg) was administered intraperitoneal to induce acute lung injury, and the control group was injected with the same dose of saline. The GLA group received glabridin 30 mg/kg at the same time. Glabridin was given intragastric infusion administration 1h after intraperitoneal injection. The doses of these drugs were on the basis of previous studies and our preliminary experiments [17]. All the rats in each group were euthanized at the same time. The bloods and lung tissue specimens were collected at the prescribed time.