Objective:

2

To study the anti-inflammatory action and cellular mechanism of

Oplopanax elatus

.

Methods:

2

A hot water extract of OE (WOE) was prepared and a major constituent

syringin

was successfully isolated. Its content in WOE was found to be 214.0 μg/g dried plant (w/w). Their anti-inflammatory activities were examined using RAW 264.7 macrophages and a mouse model of croton oil-induced ear edema.

Results:

2

In lipopolysaccharide (LPS)-treated RAW 264.7 cells

a mouse macrophage cell line

WOE was found to significantly and strongly inhibit cyclooxygenase-2 (COX-2)-induced prostaglandin E

2

(PGE

2

) production [half maximal inhibitory concentration (IC

50

)=135.2 μg/mL] and inducible nitric oxide synthase (iNOS)-induced NO production (IC

50

=242.9 μg/mL). In the same condition

WOE was revealed to inhibit NO production by downregulating iNOS expression

mainly by interrupting mitogen activated protein kinases (MAPKs)/activator protein-1 (AP-1) pathway. The activation of all three major MAPKs

p38 MAPK

extracellular signal-regulated kinase (ERK)

and c-Jun N-terminal kinase

was inhibited by WOE (50–300 μg/mL). On the other hand

WOE reduced PGE2 production by inhibiting COX-2 enzyme activity

but did not affect COX-2 expression levels. In addition

WOE inhibited the production of proinflammatory cytokines such as interleukin-6 and tumor necrosis factor-α. In croton oil-induced ear edema in mice

oral administration of WOE (50–300 mg/kg) dose-dependently inhibited edematic inflammation.

Conclusion:

2

Water extract of OE exhibited multiple anti-inflammatory action mechanisms and may have potential for treating inflammatory disorders.