Anti-inflammatory effect of kamebakaurin in in vivo animal models.

We have identified kamebakaurin as an inhibitor of NF-KB and elucidated its molecular mechanism as a specific inhibitor in the DNA-binding activity of the p50 subunit of NF-KB. Here, we describe its anti-inflammatory activity in in vitro and in vivo models. Kamebakaurin dose-dependently inhibited not only the expression of inflammatory NF-KB target genes such as iNOS,COX-2, and TNF-x, but also the production of PGE2 and TNF-a in LPS-stimulated RAW264.7 cells. Moreover, in an air pouch model of inflammation, it suppressed the recruitment of neutrophils,production of TNF-a as well as PGE2 in the pouch exudates induced by carrageenan. In addition, kamebakaurin dose-dependently suppressed the inflammation in an adjuvant arthritis model. Oral administration of 20 mg/kg kamebakaurin resulted in the 75% decrease of paw volume. Taken together, kamebakaurin, a specific inhibitor of DNA-binding activity of the p50 subunit, is a valuable candidate for the intervention in NF-KB-dependent pathological conditions such as inflammation.

In vitro structure-activity relationship and in vivo studies for a novel class of cyclooxygenase-2 inhibitors: 5-aryl-2,2-dialkyl-4-phenyl-3(2H)furanone derivatives.

5-Aryl-2,2-dialkyl-4-phenyl-3(2H)furanone derivatives were studied as a novel class of selective cyclooxygenase-2 inhibitors with regard to synthesis, in vitro SAR, antiinflammatory activities, pharmacokinetic considerations, and gastric safety. 1f, a representative compound for methyl sulfone derivatives, showed a COX-2 IC(50) comparable to that of rofecoxib. In case of 20b, a representative compound for sulfonamide derivatives, a potent antiinflammatory ED(50) of 0.1 mg kg(-1) day(-1) was observed against adjuvant-induced arthritis by a preventive model, positioning 20b as one of the most potent COX-2 inhibitors ever reported. Furthermore, 20b showed strong analgesic activity as indicated by its ED(50) of 0.25 mg/kg against carrageenan-induced thermal hyperalgesia in the Sprague-Dawley rat. 3(2H)Furanone derivatives showed due gastric safety profiles as selective COX-2 inhibitors upon 7-day repeat dosing. A highly potent COX-2 inhibitor of the 3(2H)furanone scaffold could be considered suitable for a future generation COX-2 selective arthritis medication with improved safety profiles.

Torilin from Torilis japonica, as a new inhibitor of testosterone 5 alpha-reductase.

The methanolic extract of the fruits of Torilis japonica showed a potent inhibition against 5 alpha-reductase activity in vitro. Bioassay-guided fractionation of the methanol extract of the fruits followed by repeated silica gel chromatography led to the isolation of an active principle and its structure was identified as torilin on the basis of spectroscopic data. Torilin (IC50 = 31.7 +/- 4.23 microM) showed a stronger inhibition of 5 alpha-reductase than alpha-linolenic acid (IC50 = 160.3 +/- 24.62 microM) but was weaker than finasteride. (IC50 = 0.38 +/- 0.06 microM). Simple guaiane-type compounds, such as (-)-guaiol and guaiazulene showed weak inhibitory effects on the 5 alpha-reductase activity with IC50 values of f 81.6 microM and 100.8 microM, respectively, while azulene was not active. These results suggest that both degrees of unsaturation and the side-chain in the guaiane skeleton are important for the manifestation of 5 alpha-reductase inhibition.

Inhibitory effects of natural sesquiterpenoids isolated from the rhizomes of Curcuma zedoaria on prostaglandin E2 and nitric oxide production.

Beta-turmerone and ar-turmerone, sesquiterpenoids isolated from the rhizome of Curcuma zedoaria, inhibited lipopolysaccharide (LPS)-induced prostaglandin E 2 production in cultured mouse macrophage cell RAW 264.7 in a dose-dependent manner (IC 50 = 7.3 microM for beta-turmerone; IC 50 = 24.0 microM for ar-turmerone). In addition, these compounds exhibited inhibitory effects on LPS-induced nitric oxide production in the cell system.