Anti-inflammatory action of YHQ by regulating 5-LOX/COX-2/NF-κB/MAPKs/Akt signaling pathways in RAW 264.7 macrophage cells

Yan-Hou-Qing (YHQ), a traditional Chinese medicine (TCM) formula including fifteen herbal medicines has been used for acute pharyngitis and cough treatment in Oriental medicine. However, anti-inflammatory activities of YHQ are poorly understood. The anti-inflammatory activities of YHQ were evaluated via enzyme-linked immunosorbent assay (ELISA), and the underlying mechanisms were further determined using western blot in lipopolysaccharide (LPS)-stimulated RAW 264.7 murine macrophage cells in vitro. Anti-inflammation study revealed that YHQ inhibits the release of prostaglandin E2 (PGE2) potently by suppressing the protein expression of cyclooxygenase-2 (COX-2) and leukotriene B4 (LTB4) by reducing arachidonate 5-lipoxygenase (5-LOX) in LPS-stimulated RAW 264.7 macrophages. Further study demonstrated that YHQ inhibits the production of the pro-inflammatory cytokines interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α in LPS-stimulated RAW 264.7 macrophages by attenuating the phosphorylation p65 subunit of nuclear factor-kappaB (NF-κB). The suppressive effects of YHQ on LPS-stimulated inflammatory cytokines and mediators can be attributed to the suppression of YHQ on the phosphorylation of Akt and c-Jun N-terminal kinases (JNK), extracellular signal-regulated kinase (ERK), and p38 MAPKs. This study suggested that YHQ can be a preventive and potent therapeutic candidate for the management of inflammatory-mediated immune disorders.