FIGURE 1.

Calycosin protects against cecal ligation and puncture (CLP)-induced septic acute lung injury. Mice were anesthetized and CLP procedure was performed. Sham mice were operated in the same procedure as CLP mice except for the ligation and puncture. The ligated mice were treated with calycosin by gavage at 0 and 6 h after CLP. After CLP for 12 h, mice were anesthetized and sacrificed. (A) Lung tissues were stained with hematoxylin and eosin. Histopathologic scores were calculated according to the severity of lung damage. (B) Lung tissue slides were stained by F4/80 immunohistochemistry. The numbers of positive cells were counted and statistically analyzed. (C) The lower part of the right lung was excised and weighed to obtain the wet weight. Then, the wet lung was dried in an oven at 72°C for 48 h to obtain the dry weight. The ratio of wet to dry (W/D) weight was calculated to assess the lung edema. (D) The total cell number in the BALF was determined. (E–G) The cell numbers in the BALF, including macrophages, lymphocytes, and neutrophils, were determined by the Wright–Giemsa staining. (H) MPO activity was determined. All the quantitative data (A–G) are presented as means ± SEM. *p < 0.05; **p < 0.01 vs. the CLP group. (I) Mice were treated with different doses of calycosin by gavage once per day after CLP. The mortality of mice was monitored every 24 h for 5 days after CLP (10 mice per group). The Kaplan–Meier method was used to compare the differences among groups. *p < 0.05 vs. the CLP group.