Quzhou Fructus Aurantii Extract suppresses inflammation via regulation of MAPK, NF-κB, and AMPK signaling pathway

The anti-inflammatory activity of Quzhou Fructus Aurantii Extract (QFAE) has been reported recently. Thus, present study aims to explore the mechanism of anti-inflammation of QFAE in vitro and in vivo to develop a lung phylactic agent. The anti-inflammatory mechanism of QFAE in RAW 264.7 cells and acute lung injury (ALI) mice model was determined by cytokines analysis, histopathological examination, Western blot assay, immunofluorescence, and immunohistochemistry analysis. The results showed that QFAE restrained mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) signaling pathways in LPS-induced RAW 264.7 cells, whereas AMP-activated protein kinase (AMPK) signaling pathways were activated, as revealed by prominent attenuation of phosphorylation of ERK, JNK, p38, p65, IκBα, RSK and MSK, and overt enhancement of phosphorylation of ACC and AMPKα. The levels of pro-inflammatory cytokines TNF, IL-6, and IL-1β were suppressed, whereas the level of anti-inflammatory cytokine IL-10 increased after pretreatment with QFAE in vivo and in vitro. Moreover, QFAE prevented mice from LPS-provoked ALI, bases on alleviating neutrophils, and macrophages in bronchoalveolar lavage fluid (BALF) and mitigatingpulmonary histological alters, as well as hematological change. The MAPK and NF-κB signaling pathways in LPS-stimulated ALI mice were dampened by QFAE pretreatment, whereas AMPK signaling pathways were accelerated, as testify by significant restraint of phosphorylation of ERK, JNK, p38, p65, and IκBα, and distinct elevation of phosphorylation of ACC and AMPKα. The remarkable anti-inflammatory effect of QFAE is associated with the suppression of MAPK and NF-κB signaling pathways and the initiation of AMPK signaling pathway.