Polygonatum sibiricum polysaccharides prevent LPSinduced acute lung injury by inhibiting inflammation via the TLR4/Myd88/NFκB pathway

Inflammation plays an important role in cases of acute lung injury (ALI), and the Tolllike receptor 4/nuclear factorκB (TLR4/NFκB) pathway, which can be regulated by Polygonatum sibiricum polysaccharides (PSPs), is closely related to the dynamics of lipopolysaccharide (LPS)induced inflammation. Thus, we sought to evaluate whether or not PSPs prevent LPSinduced ALI by way of inhibiting inflammation via the TLR4/NFκB pathway in rats. We established an ALI rat model by tracheal instillation of LPS, and by preinjection of PSPs into rats to examine PSPs in the ALI rat model. We found that PSPs attenuated LPSinduced lung pathological changes in ALI rats, decreased LPSinduced myeloperoxidase (MOP) activity, and elevated malondialdehyde (MDA) levels in lung tissue. However, PSPs also decreased the LPSinduced increase in the neutrophil ratio, and decreased inflammatory factor levels in bronchoalveolar lavage fluid (BALF). Moreover, PSPs decreased LPSinduced increases in inflammatory factors measured by mRNA expression, and altered the levels of expression of TLR4, medullary differentiation protein 88 (Myd88), pIKBα/IKBα and pp65/p65 proteins in lung tissue. In vitro, PSPs also reduced apoptosis induced by LPS in BEAS2B cells by suppressing inflammation through its effect of inhibiting the TLR4/NFκB pathway. In conclusion, our results suggest that PSPs may be a potential drug for effective treatment of LPSinduced ALI, due to the ability to inhibit inflammation through effects exerted on the TLR4/Myd88/NFκB pathway.