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Peroxisome proliferator-activated receptors (PPARs) are key regulators of lipid and glucose metabolism and have become important therapeutic targets for various diseases. The phytochemical investigation of the chloroform-soluble extract of Chromolaena odorata led to the isolation of a PPAR-gamma agonist, (9 S,13 R)-12-oxo-phytodienoic acid (1), together with 12 other compounds. The structures of chromomoric acid G (2), a new dehydrogenated derivative of 1, and chromolanone (3) were elucidated based on spectroscopic methods. Compound 1 showed a significant effect on PPAR-gamma activation in comparison with rosiglitazone. However, compound 2 was inactive, suggesting that the dehydrogenation of the prostaglandin-like structure in 1 abrogates its PPAR-gamma agonistic activity.

Sauchinone, a known lignan, was isolated from the root of Saururus chinensis as an active principle responsible for inhibiting the production of NO in LPS-stimulated RAW264.7 cells by activity-guided fractionation. Sauchinone dose-dependently inhibited not only the production of NO, but also the expression of iNOS mRNA and protein in LPS-stimulated RAW 264.7 cells. Furthermore, sauchinone prevented LPS-induced NF-kappaB activation, which is known to play a critical role in iNOS expression, assessed by a reporter assay under the control of NF-kappaB. However, an electrophoretic mobility shift assay (EMSA) demonstrated that sauchinone did not suppress the DNA-binding activity of NF-kappaB or the degradation of IkappaB-alpha induced by LPS. Further analysis revealed that transactivation activity of RelA subunit of NF-kappaB was dose-dependently suppressed in the presence of sauchinone. Taken together, our results suggested that sauchinone could inhibit production of NO in LPS-stimulated RAW264.7 cells through the suppression of NF-kappaB by inhibiting transactivation activity of RelA subunit.

A methanolic extract of the whole plant of Isodon japonicus (Labiatae) showed potent inhibition on the LPS-induced nitric oxide (NO) and prostaglandin E2 (PGE2) production in RAW264.7 cells. Four known kaurane diterpenes were isolated by activity-guided fractionation and their structures were identified as kamebanin (1), kamebacetal A (2), kamebakaurin (3), excisanin A (4). All compounds also inhibited the LPS-induced NF-kappaB activation as assessed by NF-kappaB reporter assay and electrophoretic mobility shift assay (EMSA). Compounds 2-4 showed comparable inhibitory effects on the LPS-induced production of NO and PGE2, and activation of NF-kappaB without affecting cell viability. These results suggest that kaurane diterpenes could exert their inhibitory effects on the production of NO and PGE2 through the suppression of NF-kappaB activation, and be partially responsible for the anti-inflammatory activities of the genus Isodon.

The anticomplementary activity of compounds isolated from the heartwood of Caesalpinia sappan L. (Leguminosae) was investigated. The sterol mixture (campesterol 11.2%, stigmasterol 18.9% and beta-sitosterol 69.9%) was most potent and brazilin, brazilein, and protosappanin E showed a new anticomplementary activity on the complement system in vitro.

A sesquiterpene compound reversing multidrug-resistance in cancer cells was isolated from the fruits of Torilis japonica and the structure was identified as torilin. Torilin potentiated the cytotoxicities of adriamycin, vinblastine, taxol and colchicine against multidrug-resistant KB-V1 and MCF7/ADR cells.

A bioassay-guided isolation of an ethyl acetate-soluble extract of the aerial parts of Inula britannica var. chinensis (Rupr.) Regel, using an in vitro NF-κB reporter gene assay, led to the isolation of four new sesquiterpene dimers bearing a norbornene moiety, inulanolides A - D (1 - 4), and three known sesquiterpenes, 1,6α-dihydroxyeriolanolide (5), 1-acetoxy-6α-hydroxyeriolanolide (6), and eupatolide (7). The structures of the new compounds were elucidated by spectroscopic methods. Among these compounds, inulanolides B and D (2 and 4) and eupatolide (7), exhibited potent inhibitory activity on the LPS-induced NF-κB activation with IC 50 values of 0.49 pM, 0.48 pM, and 1.54 μM, respectively. Consistent with their inhibitory effect on NF-KB activation, compounds 2, 4, and 7 also strongly inhibited the production of NO and TNF-a in the LPS-stimulated RAW264.7 cells with IC 50 values in the range of 2 pM.

We have identified kamebakaurin as an inhibitor of NF-κB and elucidated its molecular mechanism as a specific inhibitor in the DNA-binding activity of the p50 subunit of NF-κB. 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-κB target genes such as iNOS, COX-2, and TNF-a, but also the production of PGE 2 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 PGE 2 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-κB-dependent pathological conditions such as inflammation.

A new diterpene glycoside, acantrifoside D ( 1), as well as three known diterpenes (2 - 4) were isolated from the stem bark of Acanthopanax trifoliatus from Vietnam. Based on 1D and 2D NMR spectroscopic data, their chemical structures were determined to be 16alpha,17-dihydroxy- ent-kauran-19-oic acid 16- O-beta- D-glucopyranoside 19- O-beta- D-glucopyranosyl ester (1), 16alpha H,17-isovalerate- ent-kauran-19-oic acid (2), ent-kaur-16-en-19-oic acid ( 3), and ent-pimara-8(14),15-dien-19-oic acid (4). Compounds 2 - 4 had strong inhibitory effects against COX-1 in an in vitro assay, with IC50 values of 0.21, 0.15 and 0.19 mM, respectively.

The aim of this study was to investigate the protective effect of acanthoic acid, a diterpene isolated from the root bark of Acanthopanax koreanum, on liver injury induced by either tert-butyl hydroperoxide (tBH) or carbon tetrachloride in vitro and in vivo. In vitro, the cellular leakage of lactate dehydrogenase (LDH) following treatment with 1.5 mM tBH for 1 h, was significantly inhibited by co-treatment with acanthoic acid (25 and 5 microg/mL) and the ED (50) of acanthoic acid was 2.58 microg/mL (8.5 microM). The cellular leakage of LDH following one hour of treatment with 2.5 mM CCl (4) was significantly inhibited by co-treatment with acanthoic acid (25 microg/mL) and the ED (50) of acanthoic acid was 4.25 microg/mL (14.1 microM). Co-treatment with acanthoic acid significantly inhibited the generation of intracellular reactive oxygen species (ROS) and intracellular glutathione (GSH) depletion induced by tBH or CCl (4). Acanthoic acid pretreatment (100 mg/kg per day for four consecutive days, p. o.) significantly reduced levels of aspartate transaminase and alanine transaminase in acute liver injury models induced by either tBH or carbon tetrachloride. Treatment with acanthoic acid (100 mg/kg, p. o.) at 6, 24, and 48 hours after carbon tetrachloride subcutaneous injection significantly reduced the levels of aspartate transaminase and alanine transaminase in serum. Histological observations revealed that fatty acid changes, hepatocyte necrosis and inflammatory cell infiltration in CCl (4)-injured liver were improved upon treatment with acanthoic acid. In vivo treatment with acanthoic acid was not able to modify CYP2E1 activity and protein expression in liver microsomes at the dose used, showing that the hepatoprotective effect of acanthoic acid was not mediated through inhibition of CCl (4) bioactivation. From the results above, acanthoic acid had a protective effect against tBH- or CCl (4)-induced hepatotoxicity in vitro and in vivo.

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.

Furanoligularenone (1), a known eremophilane, was identified from Ligularia fischeri (Compositae) together with 3-oxo-8alpha-hydroxy-10alphaH-eremophila-1,7(11)-dien-12,8beta-olide (2) and 3-oxo-8alpha-methoxy-10alphaH-eremophila-1,7(11)-dien-12,8beta-olide (3), by its potent inhibition of LPS-induced nitric oxide (NO) and prostaglandin E2 (PGE2) production in RAW 264.7 cells. Compound 1 also suppressed the expression of iNOS and COX-2 mRNA and protein in a dose-dependent manner. Taken together, compound 1 inhibits the production of NO and PGE2 at the transcription of iNOS and COX-2 genes, and would be responsible for the anti-inflammatory activities of the Ligularia fischeri.

A sesquiterpene lactone, costunolide (CTN), was identified from Magnolia grandiflora together with parthenolide (PTN) by its strong inhibition of LPS-induced NF-kappa B activation. CTN, which showed more potent inhibition than PTN in the NF-kappa B activation, strongly suppressed nitric oxide (NO) production in LPS-stimulated RAW 264.7 cells. RT-PCR and Western blot analyses demonstrated that CTN suppressed the expression of iNOS mRNA and protein in a dose-dependent manner. CTN also significantly inhibited LPS-induced DNA-binding activity of NF-kappa B as well as the LPS-induced degradation of I kappa B-alpha and -beta. Furthermore, CTN inhibited LPS-induced phosphorylation of I kappa B-alpha. These findings support that CTN inhibits NO production by down-regulating iNOS expression, at least, in part through the inhibition of I kappa Bs' phosphorylation and degradation, which are essential for the activation of NF-kappa B.

A methanolic extract of Commelina communis showed potent inhibitory activity against alpha-glucosidase. One pyrrolidine alkaloid, 2,5-dihydroxymethyl-3,4-dihydroxypyrrolidine (DMDP, 1) and four piperidine alkaloids, 1-deoxymannojirimycin (2), 1-deoxynojirimycin (3), alpha-homonojirimycin (4) and 7-O-beta-D-glucopyranosyl alpha-homonojirimycin (5) were isolated by bioassay-directed fractionation and separation. These compounds have been identified for the first time from Commelina communis, supporting the pharmacological basis of this plant that has been used as a traditional herbal medicine for the treatment of diabetes.