LAUSR

OBJECTIVE To compare the protective effect of Xuebijing injection versus Sivelestat sodium on acute lung injury/acute respiratory distress syndrome (ALI/ARDS) rats. METHODS A total of 71 male Sprague-Dawley (SD) rats were randomly divided into the blank control group (n = 8), ALI/ARDS model group (n = 21), Xuebijing injection group (n = 21) and Sivelestat sodium group (n = 21). Rats in the blank control group were injected with normal saline while the other three groups were intravenously injected 25 mg/kg lipopolysaccharide (LPS) via the tail vein to establish ALI/ARDS model. After induction of ALI/ARDS model, the blank control group and ALI/ARDS model group were given intraperitoneal injection of an equal volume of normal saline twice a day. Rats in the Xuebijing injection group were given tail vein injection of 8 mL/kg Xuebijing injection twice a day, and those in the Sivelestat sodium group were given intraperitoneal injection of 100 mg/kg Sivelestat sodium three times a day. All rats were administered continuously for five days. During the experiment, the general status of rats was observed, and the weight and survival were recorded. At the end of the experiment, bronchoalveolar lavage fluid (BALF) of rats was collected for the detection of inflammatory cells and inflammatory factors. Histopathological changes of rats lung tissue were observed. RESULTS Compared with the ALI/ARDS model group, the Xuebijing injection group and Sivelestat sodium group had significantly decreased white blood cell (WBC) count and percent of neutrophil (NEU%) [WBC (×109/L): 55.86±6.68, 49.96±6.76 vs. 73.13±7.35, NEU%: 0.459±0.077, 0.315±0.047 vs. 0.709±0.067, all P < 0.05], significantly increased percent of lymphocytes (LYM%: 0.412±0.067, 0.517±0.051 vs. 0.232±0.057, both P < 0.05), and reduced interleukin-6 (IL-6) level (ng/L: 295.2±39.7, 281.9±33.1 vs. 469.6±77.0) in BALF. However, there were no significant differences in these parameters between the Xuebijing injection group and Sivelestat sodium injection group (all P > 0.05). Survival rate at the end of experiment was higher in the Xuebijing group than that in the Sivelestat sodium injection group and ALI/ARDS model group [52.4% (11/21) vs. 28.6% (6/21), 14.3% (3/21)], and survival rate at the end of experiment was higher in the Sivelestat sodium injection group than that in the ALI/ARDS model group, but the differences were not statistically significant (P > 0.05). In addition, weight and weight growth rate in the Xuebijing injection group were higher than the Sivelestat sodium group at the end of the experiment [weight (g): 217.1±6.4 vs. 207.1±7.0, weight growth rate: (-0.9±2.8)% vs. (-4.3±3.5)%], there were no significant difference between the two groups (both P > 0.05). Lung histopathology in the ALI/ARDS model group revealed high level of inflammatory exudate and inflammatory cells infiltrated in the alveoli of rats, along with damage of local alveolar epithelial cell and alveolar structure. However, these histological changes were improved in the Xuebijing injection group and in the Sivelestat sodium group. CONCLUSIONS Xuebijing injection can alleviate ALI/ARDS-induced lung injury and systemic damage and improve the survival of rats by inhibiting inflammation. The protective effect of Xuebijing injection is essentially consistent with that of Sivelestat sodium.