Abstract

Sorbus commixta has been known as enthopharmacologically valuable plant in Korea, China and Japan. This plant has been reported to display numerous pharmacological activities such as anti-oxidative, anti-ice nucleation, anti-vascular inflammation, anti-lipid peroxidation, anti-atherogenic, and vasorelaxant effects. Although numerous pharmacological potentials have been demonstrated, immunomodulatory effect of this plant has not been fully elucidated yet. To evaluate its anti-inflammatory activity, macrophages activated by lipopolysaccharide (LPS) were employed and the production of inflammatory mediators was explored in terms of understanding its molecular inhibitory mechanism. 70% ethanol extract (Sc-EE) from S. commixta strongly suppressed the production of nitric oxide (NO) and prostaglandin (PG) E₂ but not tumor necrosis factor (TNF)-α. The extract also clearly diminished the mRNA levels of inducible NO synthase (iNOS) and cyclo-oxygenase (COX)-2, implying that the inhibition occurs at the transcriptional level. Indeed, Western blot analysis and luciferase activity assay revealed that Sc-EE remarkably suppressed AP-1 translocation and its activity, respectively. In agreement, this extract strongly suppressed the phosphorylation of JNK, a prime enzyme responsible for AP-1 translocation. Therefore, our results suggest that Sc-EE can be applied as an anti-inflammatory herbal medicine. To prove this possibility,in vivo efficacy test will be further continued in the following project.

Key words: Sorbus commixta, macrophages, inflammatory mediators, AP-1 translocation, JNK activation.