Anti-inflammatory action of phenolic compounds fromGastrodia elata root

• Published in: Archives of pharmacal research 2006-10, Vol.29 (10), p.849-858
• Main Authors: Lee, Ji Yun, Jang, Young Woon, Kang, Hyo Sook, Moon, Hee, Sim, Sang Soo, Kim, Chang Jong
• Format: Article
• Language: English
• Subjects: acetic acid; analgesic effect; analgesics; anti-inflammatory activity; anti-inflammatory agents; antioxidant activity; arachidonic acid; benzyl alcohol; chromatography; dose response; ears; edema; ethyl acetate; free radical scavengers; hydroxybenzaldehyde; leukemia; methane; methanol; Orchidaceae; phenolic compounds; prostaglandin synthase; rats; reactive oxygen species; screening; solvents; structure-activity relationships; vanillin
• ISSN: 0253-6269; 1976-3786
• DOI: 10.1007/bf02973905

Previous screening of the pharmacological action ofGastrodia elata (GE) root (Orchidaceae) showed that methanol (MeOH) extracts have significant anti-inflammatory properties. The anti-inflammatory agents of GE, however, remain unclear. In this experiment, MeOH extracts of GE were fractionated with organic solvents for the anti-inflammatory activity-guided separation of GE. Eight phenolic compounds from the ether (EtOEt) and ethyl acetate (EtOAc) fractions were isolated by column chromatography: 4-hydroxybenzaldehyde (I), 4-hydroxybenzyl alcohol (II), benzyl alcohol (III), bis-(4-hydroxyphenyl) methane (IV), 4(4′-hydroxybenzyloxy)benzyl methylether (V), 4-hydroxy-3-methoxybenzyl alcohol (VI), 4-hydroxy-3-methoxybenzaldehyde (VII), and 4-hydroxy-3-methoxybenzoic acid (VIII). To investigate the anti-inflammatory and anti-oxidant activity of these compounds, their effects on carrageenan-induced paw edema, arachidonic acid (AA)-induced ear edema and analgesic activity in acetic acid (HAc)-induced writhing response were carried outin vivo; cyclooxygenase (COX) activity, reactive oxygen species (ROS) generation in rat basophilic leukemia (RBL 2H3) cells and 1,1-diphenyl-2-picryl-hydroazyl (DPPH) scavenging activity were determinedin vitro. These phenolic compounds not only had anti-inflammatory and analgesic propertiesin vivo, but also inhibited COX activity and silica-induced ROS generation in a dose-dependent manner. Among these phenolic compounds, compound VII was the most potent anti-inflammatory and analgesic. Compound VII significantly inhibited silica-induced ROS generation and compound VI significantly increased DPPH radical scavenging activity. Compounds I, II and III significantly inhibited the activity of COX-I and II. These results indicate that phenolic compounds of GE are anti-inflammatory, which may be related to inhibition of COX activity and to anti-oxidant activity. Consideration of the structure-activity relationship of the phenolic derivatives from GE on the anti-inflammatory action revealed that both C-4 hydroxy and C-3 methoxy radicals of benzyl aldehyde play an important role in anti-inflammatory activities.