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

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 E2 (PGE2) 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 PGE2 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, PGE2, interleukin (IL)-6, IL-1β, and tumor necrosis factor-α (TNF-α) 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)-κB 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.