Amelioration of an LPS-induced inflammatory response using a methanolic extract of Lagerstroemia ovalifolia to suppress the activation of NF-B in RAW264.7 macrophages

Abstract

Lagerstroemia ovalifolia Teijsm. & Binn. has traditionally been used as an herbal medicine and possesses anti-inflammatory properties. However, the mechanisms underlying its anti-inflammatory effects remain poorly understood. For this purpose, we aimed to investigate the effects of methanolic extract of L. ovalifolia (LOME) on nitric oxide (NO) and prostaglandin E-2 (PGE(2)) production, as well as the underlying molecular mechanisms responsible for these effects, in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. We examined the effects of LOME on the production of NO and PGE(2) in LPS-stimulated RAW264.7 cells. To explore the anti-inflammatory mechanisms of LOME, we measured the mRNA or protein expression of the pro-inflammatory mediators induced by LOME in the LPS-stimulated RAW264.7 cells. LOME significantly inhibited the production of NO, PGE(2), interleukin (IL)-6, IL-1, and tumor necrosis factor- (TNF-) in LPS-stimulated RAW264.7 cells. Moreover, LOME suppressed the mRNA and protein expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and inhibited the phosphorylation of the mitogen-activated protein kinases (MAPKs), with a reduction in the nuclear translocation of nuclear factor (NF)-B in LPS-stimulated RAW264.7 cells. Taken together, these findings suggest that LOME may exert anti-inflammatory effects in vitro in LPS-stimulated RAW264.7 macrophages and thus, may have potential for use as an adjuvant treatment of inflammatory diseases.