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

Abstract

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-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.

A tiered approach to investigate the mechanism of anti-inflammatory activity of an herbal medicinal product containing a fixed combination of thyme herb and primula root extracts

“…For herbal extracts, several mechanisms of interference with the production or activity of eicosanoids have been described including the regulation of enzyme expression [8][9][10] and enzyme activity [11], but also by influencing the expression of eicosanoid receptors [8,12].…”

The Phenolic Fraction of Mentha haplocalyx and Its Constituent Linarin Ameliorate Inflammatory Response through Inactivation of NF-κB and MAPKs in Lipopolysaccharide-Induced RAW264.7 Cells

“…In general, mitogen and differentiation signals are able to activate the ERK while stress stimuli activate p38 and JNK [ 61 ]. Many studies have illustrated that the up-regulation of TNF-α, IL-1β, and IL-6 is diminished by phytochemicals through the inhibition of the activation of ERK, JNK, and p38 [ 6 , 62 ]. In this paper, MHP and linarin down-regulated the phosphorylation levels of ERK, JNK, and p38.…”

“…Macrophages are phagocytic white blood cells that play an important role in innate immune inflammatory responses. Activated macrophages secrete various cytokines such as tumor necrosis factor-α (TNF-α), interlenkin-1β (IL-1β), interlenkin-6 (IL-6), and other inflammatory cytokines [ 5 ], which show pleiotropic effects via activating adaptive immune responses and worsening inflammatory responses [ 6 ]. The nuclear factor kappa-B (NF-κB) signaling pathway is involved in regulating diverse gene expression during inflammatory responses [ 7 ].…”

Anti-inflammatory effects of a methanolic extract of Castanea seguinii Dode in LPS-induced RAW264.7 macrophage cells

“…These subunits block IκB-α in its normal state, but upon stimulation by the inflammatory response, IκB-α undergoes phosphorylation and is degraded, while NF-κB is activated (18). LPS induces the activation of NF-κB, which then stimulates the expression of pro-inflammatory cytokines, including IL-6 and TNF-α, as well as chemokines (19). Therefore, the present study confirmed that CSME suppressed LPS-induced inflammatory mediators and cytokines, as well as phosphorylation of IκB-α and p65, in RAW264.7 cells.…”