Differential inhibitory effects of inotilone on inflammatory mediators, inducible nitric oxide synthase and cyclooxygenase‐2, in LPS‐stimulated murine macrophage

Abstract

The inhibitory effects of inotilone and methylinotilone on the induction of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in murine RAW 264.7 cells activated with LPS were investigated. The results show that both hydroxyl groups on the benzene ring of the inotilone molecule are required for better anti-inflammatory effect. Western blotting and RT-PCR analyses demonstrated that inotilone blocked protein and mRNA expression of iNOS but not COX-2. Instead, inotilone inhibited prostaglandin E(2) production through decreasing the enzyme activity of COX-2. The repression of iNOS but not COX-2 expression may come from the differential effect of inotilone on nuclear factor-kappaB (NFkappaB) and CCAAT/enhancer-binding protein beta Treatment with inotilone resulted in the reduction of LPS-induced nuclear translocation of NFkappaB subunit and the NFkappaB-dependent transcriptional activity by blocking phosphorylation of inhibitor kappaB(IkappaB)alpha and p65 and subsequent degradation of inhibitor kappaBalpha. Inotilone also inhibited LPS-induced activation of PI3K/Akt and extracellular signal-regulated kinase 1/2 and p38 mitogen-activated protein kinase. Our results suggest that inotilone may have potential to be developed into an effective anti-inflammatory agent.

Anti-Inflammatory Activities of Inotilone from Phellinus linteus through the Inhibition of MMP-9, NF-κB, and MAPK Activation In Vitro and In Vivo

“…Results in vitro showed that inotilone suppressed LPS-induced production of NO, and the protein expression of iNOS and COX-2. The similar results for inotilone inhibits LPS-induced NO and PGE 2 production through modulating iNOS expression and COX-2 enzyme activity [12].…”

“…Examination of the cytotoxicity of inotilone in RAW264.7 macrophages using MTT assay has indicated that inotilone even at 25 µM did not affect the viability of RAW264.7 cells. Inotilone inhibited iNOS expression in LPS-stimulated macrophages and subsequently inhibited the NO production, whereas it decreased the enzyme activity of COX-2 instead of its expression to reduce PGE 2 production [12]. In addition, Carr-induced inflammatory response has been linked to neutrophil infiltration release NO as well as that of PGE 2 .…”

“…PL has been isolated several aromatic compounds from the cultured mycelia such as hydroxybenzaldehyde, caffeic acid, hispolon, hispidin, and inotilone [11]. We recently reported that inotilone had previously been shown to possess anti-inflammatory [12], and α-glucosidase and aldose reductase inhibitory activities [9]. This study examined the anti-inflammatory effects of inotilone by using LPS-stimulated RAW264.7 cell in vitro and Carr-induced mouse paw edema model in vivo .…”

The lipopolysaccharide-induced pro-inflammatory response in RAW264.7 cells is attenuated by an unsaturated fatty acid–bovine serum albumin complex and enhanced by a saturated fatty acid–bovine serum albumin complex

“…These results indicate that the 1:1 ratio of the FA-BSA complex was in the physiological range and did not induce any pro-inflammatory response. Inflammation leads to the up-regulation of pro-inflammatory enzymes, such as iNOS and COX-2, and the release of numerous cytokines in affected tissues and cells [37]. iNOS is a member of the NOS protein family that can catalyze the formation of NO from L-arginine [16,38].…”

Some Phytochemicals and Anti-inflammation Effect of Juice from <i>Tiliacora triandra</i> Leaves

“…The blots were washed three times for 10 min each by rinsing with PBS-T buffer (0.2% Tween 20 in 1x PBS buffer) and then were incubated with the horseradish peroxidase (HRP)-conjugated secondary antibody at dilution of 1:5,000 (Zymed Laboratories, San Francisco, CA) following washing three times with PBS-T buffer. The transferred proteins were visualized with an enhanced chemiluminescence detection kit (Amersham Pharmacia Biotech, Buckinghamshire, UK) [20,22].…”