The dichloromethane fraction from Mahonia bealei (Fort.) Carr. leaves exerts an anti-inflammatory effect both in vitro and in vivo

Ethnopharmacological relevance: Mahonia bealei has a long history of medical use in traditional Chinese medicine for the treatment of inflammatory-associated diseases. Despite numerous phytochemical and pharmacological studies, there is a lack of systematic studies to understand the cellular and molecular mechanisms of the anti-inflammatory activity of this plant. Aim of study: This study aimed to evaluate the anti-inflammatory activity of the dichloromethane fraction from M. bealei leaves (MBL-CH). Materials and methods: RAW 264.7 cells were pretreated with different concentrations of MBL-CH for 30 min prior to treatment with 1 mu g/ml of lipopolysaccharide (LPS). The nuclear factor kappa B (NF-kappa B) pathway and subsequent production of inflammatory mediators, such as nitric oxide (NO), prostaglandin E-2 (PGE(2)), and tumour necrosis factor (TNF)-alpha were investigated. Furthermore, the in vivo mouse model of LPS-induced acute lung injury (ALI) was employed to study the anti-inflammatory effects of MBL-CH. Results: Pre-treatment with MBL-CH significantly inhibited the LPS-stimulated secretion of NO, PGE(2), and TNF-alpha into the culture medium, as well as the mRNA levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and TNF-alpha, which were associated with a reduction in the phosphorylation of I kappa B alpha, Akt, and PI3K and inhibition of the transcriptional activity of NF-kappa B. Furthermore, in vivo experiments revealed that MBL-CH attenuated LPS-stimulated lung inflammation in mice. Conclusion: Taken together, our findings indicate that MBL-CH attenuates LPS-stimulated inflammatory responses in macrophages by blocking NF-kappa B activation through interference with activation of the PI3K/Akt pathway, providing scientific evidence that the plant can be employed in traditional remedies. (C) 2016 Elsevier Ireland Ltd. All rights reserved.