Evidence of anti-inflammatory activity of Schizandrin A in animal models of acute inflammation.

Schisandrin A (Sch A) is a lignin extracted from the fruit of Schisandra chinensis, which has potential anti-inflammatory properties and is used for treating various inflammatory diseases. In this study, we aimed to evaluate the anti-inflammatory effects of Sch A and the underlying mechanisms in animal models of acute inflammation. First, the anti-inflammatory effects of Sch A were evaluated preliminarily in an animal model of xylene-induced ear edema. Sch A pretreatment significantly decreased the degree of edema and inhibited telangiectasia in the ear. Second, a mouse model of paw edema was used to investigate the anti-inflammatory effects and mechanisms of Sch A. Pretreatment with Sch A significantly inhibited carrageenan-induced paw edema in mice. Hematoxylin-eosin (HE) staining of paw tissues demonstrated that Sch A inhibited the infiltration of inflammatory cells in the mouse model of paw edema. Enzyme-linked immunosorbent assay (ELISA) results indicated that the levels of inflammatory factors decreased. The western blot and immunohistochemical assay results revealed that the toll-like receptor 4/nuclear factor kappa-B (TLR4/NF-κB) pathway could play a role in the anti-inflammatory functions of Sch A. The findings demonstrated that Sch A exerts anti-inflammatory effects and may provide possible strategies for the treatment of inflammatory diseases.