Apios americana Medik Extract Alleviates Lung Inflammation in Influenza Virus H1N1-and Endotoxin-Induced Acute Lung Injury

Apios americana Medik (hereinafter Apios) has been reported to treat diseases, including cancer, hypertension, obesity, and diabetes. The therapeutic effect of Apios is likely to be associated with its anti-inflammatory activity. This study was conducted to evaluate the protective effects of Apios in animal models of acute lung injury induced by lipopolysaccharide (LPS) or pandemic H1N1 2009 influenza A virus (H1N1). Mice were exposed to LPS or H1N1 for 2-4 days to induce acute lung injury. The treatment groups were administered Apios extracts via oral injection for 8 weeks before LPS treatment or H1N1 infection. To investigate the effects of Apios, we assessed the mice for in vivo effects of Apios on immune cell infiltration and the level of pro-inflammatory cytokines in the bronchoalveolar lavage (BAL) fluid, and histopathological changes in the lung. After induction of acute lung injury, the numbers of neutrophils and total cells were lower in the Apios-treated groups than in the non-Apios-treated LPS and H1N1 groups. The Apios groups tended to have lower levels of tumor necrosis factor-a and interleukin-6 in BAL fluid. In addition, the histopathological changes in the lungs were markedly reduced in the Apios-treated groups. These data suggest that Apios treatment reduces LPS- and H1N1-induced lung inflammation. These protective effects of Apios suggest that it may have therapeutic potential in acute lung injury.