[Protective effects of sodium butyrate against lung injury in mice with endotoxemia]

The aim of the present study was to investigate the effects of sodium butyrate (SB) on systemic inflammation, lung injury and survival rate of mice with endotoxemia. Balb/c mice were pre-treated with SB or vehicle, and then endotoxemia was induced by lethal dose of lipopolysaccharide (LPS, 20 mg/kg, i.p.) and the survival rate of mice was monitored. A separated set of animals were sacrificed at 18 h after LPS challenge, and blood samples were harvested for measuring TNF-α and IL-6 levels. Lung tissues were also harvested to determine the ratio of wet weight to dry weight of lung tissue and myeloperoxidase (MPO) activity in lung tissue. In addition, the formalin-fixed lung specimens were stained with HE routinely for morphologic evaluation. The results showed that pre-treatment with SB alleviated LPS-induced morphological damage in lung tissue. This was accompanied by reduced ratio of wet weight to dry weight of lung tissue and MPO activity in lung homogenates. Additionally, the up-regulation of pro-inflammatory cytokines TNF-α and IL-6 was also suppressed by SB, while the survival rate of mice with lethal endotoxemia was significantly increased by SB pre-treatment. The results suggest that SB effectively attenuates intrapulmonary inflammatory response and improves the survival of endotoxemic mice.