BACKGROUND: The aim of this study was to investigate the protective effects of cucurbitacin B (CuB) on sepsis-induced acute lung injury (ALI) in rats.

MATERIAL AND METHODS: An ALI model was made by cecal ligation and puncture (CLP) in SD rats. Rats were randomly divided into 5 groups (n=15 per group): animals undergoing a sham CLP (sham group); animals undergoing CLP (CLP control group); animals undergoing CLP and treated with CuB at 1 mg/kg of body weight (bw) (low-dose CuB [L-CuB] group), animals undergoing CuB at 2 mg/kg of bw (mid-dose CuB [M-CuB] group); and animals undergoing CuB at 5 mg/kg of bw (high-dose CuB [H-CuB] group). Samples of blood and lung tissue were harvested at different time points (6, 12, and 24 hour post-CLP surgery) for the detection of indicators which represented ALI. Five rats were respectively sacrificed at each time point. Pathological changes of lung tissue were observed by H&E staining. Another 50 rats were distributed into the same five groups to record the 72 hour survival rates.

RESULTS: Treatment with CuB significantly increased the blood gas PaO2 levels and decreased lung wet/dry (W/D) ratio (p<0.05). It significantly reduced protein concentration, accumulation of the inflammatory cells, and levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), (p<0.05), in the bronchoalveolar lavage fluid (BALF). Pulmonary pathological damage and survival rates at 72 hours were found to be effectively improved by CuB. In addition, CuB performed its pulmonary protection effects in a dose-depended manner.

CONCLUSIONS: CuB can effectively improve the pulmonary gas exchange function, reduce pulmonary edema, and inhibit the inflammatory response in the lung, revealing that CuB may serve as a potential therapeutic strategy for sepsis-induced ALI.

Keywords: acute lung injury, Cucurbita, Inflammation Mediators, Pulmonary Edema, Sepsis