earticle

영어

Leonurus japonica (syn L. heterophyllus Sweet) or Chinese motherwort is a herbaceous annual of pantropical distribution of the Lamiaceae family. Extracts of aerial parts are used in Chinese medicine for various purposes such as heart anti-arrhythmic, sedative, antimicrobial, anticoagulant, antioxidant and anti-tumoral properties, as well as booster of the immune response. The present study illustrated that, the water and 70% ethanol extracts of L. japonica exhibited no significant effect on NO and NF-κB SEAP reporter gene assay, using LPS-stimulated RAW264.7 cells. Several metabolites have been isolated from L. japonicus that substantiate the recorded activities. Five compounds were tested for anti-inflammatory effect. Leonurine, rutine, genkwanine, and stachydrine hydrochloride showed no promising effect on NO and NF-κB. On the other hand, the novel labdan diterpene derivative, 15, 16-epoxy-3-hydroxylabda-8, 13(16), 14-trien-7-one, exhibited potent inhibitory effect on the iNOS and COX-2 protein expression using LPS-stimulated RAW264.7 cells, macrophages. As a mechanism of anti-inflammatory action shown by 15,16-epoxy-3-hydroxylabda-8,13(16), 14-trien-7-one, suppression of nuclear factor (NF)-κB activation has been documented. Furthermore, the labdan compound exhibited significant inhibitory effect on LPS-medicated NF-κB-DNA binding and AP-1-DNA binding activitiesusing electrophoretic mobility shift assay (EMSA) 32P-labeled NF-κB and AP-1 probes. Taken together, labdan diterpene 15, 16-epoxy-3-hydroxylabda-8, 13(16), 14-trien-7-one, suppressed LPS-induced NF-κB activation, resulting down-regulation of iNOS and COX-2 protein expression, which was attributable to its inhibitory action of LPS-induced NO and PGE2 production. These results may contribute to the anti-inflammatory activity of 15, 16-epoxy-3-hydroxylabda-8, 13(16), 14-trien-7-one.