Wei-Dong Xie

Sesquiterpenoids from Farfugium japonicum and their inhibitory activity on NO production in RAW264.7 cells

A new eremophilane sesquiterpenoid, namely, 3β-angeloyloxy-6β,8β-dihydroxy-9β-senecioyloxyeremophil-7(11)-en-12,8α-lactone, along with eight known sesquiterpenoids, was isolated from the rhizome of Farfugium japonicum. The structures of all isolates were identified based on analyses of spectroscopic data (HRESIMS, IR, 1D, and 2D NMR) and comparison with literature data. The inhibitory effects of compounds 1–4 on nitric oxide production in lipopolysaccaride-activated mouse macrophages were also evaluated.

1-oxoeudesm-11(13)-ene-12,8α-lactone-induced apoptosis via ROS generation and mitochondria activation in MCF-7 cells

A novel eudesmane-type sesquiterpene compound, 1-oxoeudesm-11(13)-eno-12,8a-lactone (OEL), was isolated from Aster himalaicus. Its effect on apoptosis in human breast adenocarcinoma (MCF-7) cells was investigated. MTT assay showed that OEL substantially reduced the viability of KB, MCF-7, U87, A172, and MG-63 cells. MCF-7 cells were used to further evaluate the antitumor effects and anticancer mechanisms of OEL. OEL-induced apoptosis was characterized by chromatin condensation, formation of apoptotic bodies, and phosphatidylserine on extracellular surface; these effects were confirmed by DAPI nuclear staining and flow cytometry. Increased expression of Bax and deceased expression of Bcl-2 were also observed in OELtreated MCF-7 cells. Moreover, OEL induced the loss of mitochondria membrane potential, release of cytochrome C, activation of caspase-9, and generation of reactive oxygen species. These findings indicate that reactive oxygen species generation and mitochondria activation were involved in apoptosis induced by OEL in MCF-7 cells. The results from our study demonstrated that OEL may be a promising pro-apoptotic compound that could be used to develop novel anticancer drugs.

Sesquiterpenoids from Carpesium divaricatum and their cytotoxic activity.

In the course of searching for cytotoxic terpenoids from medicinal plants in China, two new eudesmane sesquiterpenoids, 5α-hydroxy-13-methoxy-7αH,11αH-eudesm-4(15)-en-12,8β-lactone (1) and 1β-hydroxy-7αH,11αH-eudesm-4(15)-en-12,8β-lactone (2), along with fourteen known sesquiterpenoids were isolated from the whole plant of Carpesium divaricatum. The structures of new compounds were determined using spectroscopic methods, including IR, HRESIMS, and 1D and 2D NMR spectroscopy. The cytotoxicity of selected sesquiterpene lactones against human oral epidermoid carcinoma (KB), human breast cancer (MCF-7) and human hepatoma (HepG-2) cells was also evaluated by MTT method.

1-Oxoeudesm-11(13)-eno-12,8a-lactone induces G2/M arrest and apoptosis of human glioblastoma cells in vitro

Aim:To investigate the effects of 1-oxoeudesm-11(13)eno-12,8a-lactone (OEL), a novel eudesmane-type sesquiterpene isolated from Aster himalaicus, on the cell cycle and apoptosis in human glioblastoma cells in vitro.Methods:Human malignant glioblastoma cell lines U87 and A172 were used. The cytotoxicity of OEL was examined using the MTT assay. Cell apoptosis was assessed with DAPI staining and flow cytometry. DNA damage was determined by measuring the phosphorylation of H2AX using immunofluorescence staining and Western blotting. Cell cycle profiles were measured with flow cytometry. The mRNA expression of p53 and p21Waf1/Cip1 was investigated using real-time PCR. The protein expression of γ-H2AX, caspase-9, caspase-3, p53, p21Waf1/Cip1, cyclin B1, and cdc2 was analyzed with Western blotting.Results:Treatment of the malignant glioblastoma cells with OEL inhibited the cell growth in dose- and time-dependent manners (the values of IC50 at 48 and 72 h were 29.5 and 16.99 μmol/L, respectively, in U87 cells; 7.2 and 9.5 μmol/L, respectively, in A172 cells). OEL (10–30μmol/L) induced apoptosis and G2/M phase arrest in both U87 and A172 cells. OEL induced the phosphorylation of cdc2, a G2/M phase cyclin-dependent kinase, and decreased the expression of cyclin B1 required for progression through the G2/M phase in U87 cells. The compound remarkably increased the phosphorylation of H2AX in U87 cells. Moreover, OEL increased the mRNA and protein levels of p53 and its target gene p21Waf1/Cip1 in U87 cells. The compound also induced p53 phosphorylation. Pretreatment with PFT-α, a specific inhibitor of p53 transcriptional activity, could partially reverse the inhibition of OEL on the viability of U87 and A172 cells.Conclusion:OEL suppresses the growth of human glioblastoma cells in vitro via inducing DNA damage, p53-mediated cell cycle arrest and apoptosis, thus warrants further studies as a lead compound of anti-glioblastoma drug.

Telekin suppresses human hepatocellular carcinoma cells in vitro by inducing G2/M phase arrest via the p38 MAPK signaling pathway.

Aim:Telekin, isolated from the Chinese herb Carpesium divaricatum, has shown anti-proliferation effects against various cancer cells, including hepatocellular carcinoma cells. In this study, we investigated the anti-proliferation mechanisms of telekin in human hepatocellular carcinoma HepG2 cells in vitro.Methods:HepG2 cells were treated with telekin. Cell viability was evaluated using MTT assay. Flow cytometry was used to measure cell cycle profiles, ROS level and apoptosis. The protein expression levels were analyzed with Western blotting.Results:Telekin (3.75–30 μmol/L) dose-dependently inhibited the viability of HepG2 cells and induced l apoptosis. Furthermore, the treatment induced cell cycle arrest at G2/M phase, accompanied by significantly increased the phosphorylation of Cdc25A and Cdc2, and decreased Cyclin B1 level. Moreover, the treatment significantly stimulated ROS production, and increased the phosphorylation of p38 and MAPKAPK-2 in the cells. Pretreatment with the antioxidant NAC (2.5, 5, and 10 mmol/L), or the p38 MAPK inhibitor SB203580 (2.5 and 5 μmol/L) dose-dependently attenuated these telekin-induced effects in the cells.Conclusion:Telekin suppresses hepatocellular carcinoma cells in vitro by inducing G2/M phase arrest via activating the p38 MAPK pathway.

Abietane diterpenoids from Isodon inflexus

Four abietane diterpenoids, inflexanin C, inflexanin D, inflexuside A and inflexuside B, were isolated from the aerial parts of Isodon inflexus. Their respective structures were established by NMR, mass spectrometry and CD as (+)-(1S,4R,5S,7S,8S,10S,13S)-1,7,18-trihydroxy-abieta-9(11)-ene-12-one 1-monoacetate, (+)-(1S,4R,5S,10S,13S)-1,18-dihydroxy-abieta-7,9(11)-diene-12-one 1-monoacetate, (-)-(1S,5S,10S,11R,13R)-1,11,13-trihydroxy-abieta-8-ene-7-one 1-O-β-D-glucopyranoside and (-)-(1S,5S,10S,11R,13R)-1,11,13-trihydroxy-abieta-8-ene-7-one 1-O-(2-O-coumaroyl)-β-D-glucopyranoside. All compounds showed strong inhibitory activity against nitric oxide (NO) production in RAW264.7 lipopolysaccaride (LPS)-activated macrophages.

NF-κB activation was involved in reactive oxygen species-mediated apoptosis and autophagy in 1-oxoeudesm-11(13)-eno-12,8α-lactone-treated human lung cancer cells

Abstract1-oxoeudesm-11(13)-eno-12,8α-lactone (OEL), a novel eudesmane-type sesquiterpene compound, has been shown to inhibit the growth of some cancer cell lines and induce significant apoptosis. Here, we investigated the anti-cancer activities of OEL in human lung cancer cells. Our studies demonstrated that OEL induced both apoptosis and autophagy in A549 and H460 cells. OEL-induced autophagy was assessed by appearance of autophagic vacuoles, formation of acidic vesicular organelles, conversion of LC3-I to LC3-II, recruitment of LC3-II to the autophagosomes, and activation of autophagy genes. Furthermore, administration of autophagic inhibitor 3-methyladenine augments OEL-induced apoptotic cell death. The induction of autophagy and apoptosis by OEL links to NF-κB activation and the generation of reactive oxygen species (ROS). Interruption of NF-κB activation by specific inhibitor promotes apoptosis, but decreases autophagy. ROS antioxidants (N-acetylcysteine) attenuated both OEL-induced autophagy and apoptosis. Further experiments confirmed that OEL-induced activation of ROS was increased by NF-κB inhibitor whereas NF-κB activation was not affected by ROS inhibition. These findings suggest that OEL-elicited autophagic response plays a protective role that impedes cell death, and inhibition of autophagy could be an adjunctive strategy for enhancing the chemotherapeutic effect of OEL as an antitumor agent.

Sesquiterpenoids from Petasites tatewakianus

850 0009-3130/11/4705-0850 2011 Springer Science+Business Media, Inc.1) Marine College, Shandong University at Weihai, Weihai 264209, P. R. China, fax: +86 631 5688303, e-mail:wdxie@sdu.edu.cn; 2) Department of Chemical Engineering, Inha University, Incheon 402-751, Korea, fax: +82 32 8720959,e-mail: rowkho@inha.ac.kr. Published in Khimiya Prirodnykh Soedinenii, No. 5, pp. 742–743, September–October, 2011.Original article submitted June 19, 2010.

5,6-Dihydroxy-3,7,4′-trimethoxyflavonol induces G2/M cell cycle arrest and apoptosis in human hepatocellular carcinoma cells

Abstract 5,6-Dihydroxy-3,7,4′-trimethoxyflavonol (AH5), 5,6,3′-trihydroxy-3,7,4′-trimethoxyflavonol (AH22), artemetin, and oroxylin A are four flavonoids with the same 2-phenyl-chromone skeleton isolated from the Chinese herb Aster himalaicus. The aim of this study was to evaluate the structure–activity relationship of these four analogs and the mediation of AH5 cytotoxicity via G2/M arrest and apoptosis in human hepatocellular carcinoma (HCC) cells. 3-(4,5-Dimethythiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay indicated AH5 showed the better potency to inhibit proliferation in human HCC cells, which suggested hydroxyl binding to C6 is necessary to anticancer properties, whereas binding to C3′ attenuated the activities and increased toxicity in tested cells. Flow cytometry analysis revealed that AH5-induced G2/M arrest and significantly apoptosis in these cell lines. HepG-2 cells were used to further evaluate the antitumor effects and mechanisms of AH5. AH5-induced apoptosis was further confirmed by 4′,6-diamidino-2-phenylindole (DAPI) staining and the increased ratio of Bax/Bcl-2. Moreover, AH5 induced the release of cytochrome C and the activation of caspase-9 and caspase-3, thus suggesting mitochondria activation might be involved. Western blot showed that AH5 induced the phosphorylation of Cdc2 and decreased the level of Cyclin B1. These results demonstrated that AH5 could be a proapoptotic leading compound for developing novel anticancer drugs.

A new eremophilane sesquiterpene from Senecio nemorensis

A new eremophilane sesquiterpene was isolated from the MeOH extract of the aerial parts of Senecio nemorensis. Its structure was established as 11-hydroxy-1β-methoxyl-8-oxoeremophila-6,9-dien-12-oic methyl ester by extensive application of spectroscopic methods, including IR, EI-MS, HR-ESI-MS, 1D and 2D NMR spectroscopy.