Therapeutic effect of dioscin on collagen-induced arthritis through reduction of Th1/Th2

The aim of this study was to detect the therapeutic effect of dioscin on collagen-induced arthritis (CIA). Mice model of CIA was induced by chicken collagen II and arthritis index was assessed. After suspension of dioscin (100 mg/kg/d) or triptolide was intragastrically administered, the left paw swelling and body weight of each mouse were measured. Then tissue samples were assayed by histopathological analysis. The levels of Th1 and Th2 were detected by flow cytometry. The expression of p-STAT1, p-STAT4 and p-STAT6 was demonstrated by western blot analysis, and T-bet and GATA-3 expression was detected by RT-PCR. The paw swelling and arthritis index were decreased and body weight was increased in the high dose of dioscin group compared to the model group (P < 0.05). Histopathological analysis revealed that the damage of synovium tissue in dioscin and triptolide group alleviated. The ratio of Th1/Th2 in the dioscin group (0.82 ± 0.24) and triptolide group (0.99 ± 0.44) was lower than that in the model group (1.84 ± 0.70, P < 0.05). Additionally, p-STAT4 expression was decreased, and both p-STAT6 and GATA3 expression was increased in the dioscin group than that in the model group (P < 0.05). Dioscin might have some therapeutic effects on CIA through regulating the proportion of Th1/Th2 cells, which could reduce the expression of p-STAT4, increase the expression of p-STAT6 and GATA3 in the synovial tissue.     

Antifungal steroid saponins from Dioscorea cayenensis

From the rhizomes of Dioscorea cayenensis Lam.-Holl (Dioscoreaceae), the new 26- O- beta- D-glucopyranosyl-22-methoxy-3 beta,26-dihydroxy-25( R)-furost-5-en-3- O- alpha- L-rhamnopyranosyl-(1-->4)- alpha- L-rhamnopyranosyl-(1-->4)-[ alpha- L-rhamnopyranosyl-(1-->2)]- beta- D-glucopyranoside ( 1) was isolated together with the known dioscin ( 2) and diosgenin 3- O- alpha- L-rhamnopyranosyl-(1-->4)- alpha- L-rhamnopyranosyl-(1-->4)-[ alpha- L-rhamnopyranosyl-(1-->2)]- beta- D-glucopyranoside ( 3). Their structures were established on the basis of spectral data. Compound 2 exhibited antifungal activity against the human pathogenic yeasts Candida albicans, C. glabrata and C. tropicalis (MICs of 12.5, 12.5 and 25 micro g/mL, respectively) whereas 3 showed weak activity and 1 was inactive.     

小花盾叶薯蓣中的甾体成分

目的研究小花盾叶薯蓣的化学成分。方法运用正相和反相硅胶柱色谱对其化学成分进行分离，用IR，NMR，MS等方法进行结构鉴定。结果从乙醇提取物中分离鉴定出11个甾体化合物，分别鉴定为去酰百合皂苷(deacylbrownioside，I)、薯蓣皂苷元-双葡糖苷(diosgenin-diglucoside，II)、前薯蓣皂苷A(prosapogenin A of dioscin，III)、薯蓣皂苷(dioscin，IV)、三角薯蓣皂苷宁(deltonin，V)、三角薯蓣皂苷(deltoside，VI)、甲基三角薯蓣皂苷(methyl deltoside，VII)、薯蓣皂苷元 3-O-β-D-吡喃葡糖基-(1→3)- β -D-吡喃葡糖基-(1→4)-［ α-L-吡喃鼠李糖基-(1→2)］- β -D-吡喃葡糖苷{diosgenin 3-O-β-D-glucopyranosyl-(1→3)- β -D-glucopyranosyl-(1→4)- ［α-L-rhamnopyranosyl-(1→2)］- β -D-glucopyranoside，VIII}、小花盾叶薯蓣苷(parvifloside，IX)、甲基小花盾叶薯蓣苷(methyl parvifloside，X)、薯蓣皂苷元(diosgenin，XI)、以及β-谷甾醇(β-sitosterol)和豆甾醇(stigmasterol)的混合物。结论化合物X为一新化合物，VII与X分别为VI和IX的甲醚衍生物，可能为分离过程中所产生。I系首次从薯蓣属植物中分离得到，II和IV均为首次从小花盾叶薯蓣中分离得到。     

穿龙薯蓣总皂苷中甾体皂苷的分离与鉴定

目的研究穿龙薯蓣总皂苷中水溶性甾体皂苷,寻找新的生物活性化合物。方法用硅胶柱色谱、薄层色谱及高效液相色谱等进行分离,通过酸水解、理化常数和波谱学分析(IR,NMR,MS,HMQC,HMBC)鉴定化合物结构。结果从穿龙薯蓣总皂苷中分得2个甾体皂苷(1个水难溶性皂苷和1个水溶性皂苷),其化学结构分别鉴定为薯蓣皂苷元-3-O-{α-L-鼠李糖(1→2)-［β-D-葡萄糖(1→3)］}-β-D-葡糖皂苷(I),薯蓣皂苷元-3-O-［α-L-鼠李糖(1→3)-α-L-鼠李糖(1→4)-α-L-鼠李糖(1→4)］-β-D-葡糖皂苷(II)。结论II为首次从穿龙薯蓣中分离得到的新化合物,命名为穿龙薯蓣皂苷Dc。     

Microbial metabolism of pseudoprotodioscin

Microbial transformation of the furostanol saponin pseudoprotodioscin ( 1) using Aspergillus fumigatus resulted in the isolation of two new steroidal metabolites, 3- O-[bis- alpha- L-rhamnopyranosyl-(1-->2 and 1-->4)- beta- D-glucopyranosyl]-22 R,25 R-spirost-5-ene-3 beta,20 alpha-diol ( 2) and 3- O-[bis- alpha- L-rhamnopyranosyl-(1-->2 and 1-->4)- beta- D-glucopyranosyl]-25 R-furost-5-ene-3 beta,22 alpha,26-triol ( 3), in addition to the previously reported steroidal saponins: dioscin ( 4) and progenin II ( 5). The structure elucidation of these metabolites was based primarily on 1D and 2D NMR analyses. Metabolites 2 - 5 showed significant cytotoxicity against cancer cell lines A375, L929, and HeLa with IC (50) values ranging from 1.18 microM to 17.88 microM.     

薤白中两种新甾体皂甙成分

从中药薤白(Allium macrostemon Bunge)鳞茎中分得两种流的甾体皂甙,薤白甙甲(macrostemonoside A,1)和薤白甙丁(macrostemonoside D,2),通过光谱(IR,MS,¹HNMR,¹³CNMR,¹H-¹H COSY和NOESY等)分析和衍生化研究,分别确定为:tigogenin-3-O-β-D-glucopyranosyl(1→2)[β-D-glucopyranosyl(1→3)]-β-D-glucopyranosyl(1→4)-β-D-galactopyranoside(1)和tigotenin-3-O-β-D-glucopyranosyl(1→2)[β-D-glucopyranosyl(1→3)(6-O-acetyl-β-D-glucopyranosyl)](1→4)-β-D-galactopyranoside(2)。     

Triterpenoid saponins from Stauntonia chinensis

A new triterpenoid saponin, named stauntoside A (1) along with four known saponins (2,3,4,5) was isolated from Stauntonia chinensis DC., (Lardizabalaceae). Their structures were elucidated by spectroscopic analysis and chemical methods as 3-O-alpha-L-arabinopyranosyl-30-norhederagenin -28-O-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl ester (1), 3-O-alpha-L-arabinopyranosyl-30- norhederagenin-28-O-alpha-L-rhamnopyranosyl-(1 --> 4)-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl ester (2), 3-O-alpha-L-rhamnopyranosyl-(1 --> 2)-alpha-L-arabinopyranosyl-30-norhederagenin-28-O-alpha-L- rhamnopyranosyl-(1 --> 4)-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl ester (3), 3-O-alpha-L- arabinopyranosyl-hederagenin-28-O-alpha-L-rhamnopyranosyl-(1 --> 4)-beta-D-glucopyranosyl-(1 --> 6)-beta-D- glucopyranosyl ester (4), 3-O-alpha-L-rhamnopyranosyl-(1 --> 2)-alpha-L-arabinopyranosyl-hederagenin -28-O-alpha-L-rhamnopyranosyl-(1 --> 4)-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl ester (5). The (1)H and (13)C NMR data for Glycoside L-G1 or Sinofoside A are paradox in the reported before. Thus, the structure elucidation of saponin 2, known as Glycoside L-G1 or Sinofoside A, was discussed and the unambiguous assignments were given.     

Four new triterpenoid saponins from Ardisia gigantifolia Stapf. and their cytotoxic activity

Four new oleanane-type triterpenoid saponins, cyclamiretin A 3beta-O-alpha-L-rhamnopyranosyl-(1 --> 3)-[beta-D-xylopyranosyl-(1 --> 2)]-beta-D-glucopyranosyl-(1 --> 4)-[beta-D-glucopyranosyl-(1 --> 2)]-alpha-L-arabinopyranoside (1), cyclamiretin A 3beta-O-alpha-L-rhamnopyranosyl-(1 --> 3)-[beta-D-glucopyranosyl-(1 --> 3)-beta-D-xylopyranosyl-(1 --> 2)]-beta-D-glucopyranosyl-(1 --> 4)-[beta-D-glucopyranosyl-(1 --> 2)]-alpha-L-arabinopyranoside (2), cyclamiretin A 3beta-O-alpha-L-rhamnopyranosyl-(1 --> 3)-[beta-D-xylopyranosyl-(1 --> 2)]-beta-D-glucopyranosyl-(1 --> 4)-[beta-D-6-O-acetylglucopyranosyl-(1 --> 2)]-alpha-L-arabinopyranoside (3) and 3beta-O-[alpha-L-rhamnopyranosyl-(1 --> 3)-[beta-D-xylopyranosyl-(1 --> 2)]-beta-D-glucopyranosyl-(1 --> 4)-[beta-D-glucopyranosyl-(1 --> 2)]-alpha-L-arabinopyranoside]-16,28-dihydroxy-30-acetoxyoleana-12-en (4), along with one known triterpene saponin and ardisiacrispin A (5) were isolated from the rhizome of Ardisia gigantifolia. Their structures were established with the help of extensive spectroscopic techniques. Furthermore, the inhibitory effects of compounds on tumor cells (MTT based) in vitro were evaluated, and compounds 1, 2, and 5 showed potent anti-tumor activities.     

Saponins from the seeds of Achras sapota

A new pentacyclic triterpenoid saponin (2) along with one known was isolated from the cotyledons of Achras sapota. Their structures were determined with the help of (1)H NMR, (13)C NMR and MS spectral data. The isolated compounds were named as 3-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl-28-O-alpha-L-rhamnopyranosyl-(1-->3)-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl protobassic acid (1) and 3-O-beta-D-glucopyranosyl-(1-->3)-beta-D-glucopyranosyl-28-O-alpha-L-rhamnopyranosyl-(1-->3)-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-16alpha-hydroxy protobassic acid (2). Compound 2 showed antibacterial activity against Gram positive and negative bacteria.     

Mechanism investigation of dioscin against CCl(4)-induced acute liver damage in mice

The mechanisms of the ameliorating effects of dioscin against CCl(4) induced acute liver damage are investigated in this study. Dioscin significantly inhibited (p<0.01) the increases of serum ALT and AST activities compared with the CCl(4)-treated animals. The hepatic lipid peroxidation formation and, concentrations of TNF-α and IL-6 were also decreased. Liver histopathologic studies and a DNA laddering assay indicated that dioscin protected hepatocytes against CCl(4)-induced apoptosis and necrosis. Furthermore, dioscin decreased the protein expressions of Fas/FasL, increased Bcl-2/Bax ratio, inhibited the release of cytochrome c from mitochondrion to cytosol and attenuated CCl(4)-induced caspase-3 and -8 activities. The expressions of ICAM-1, vimentin, prohibitin, HGF, c-MET and GSTA1 were also regulated by dioscin and iNOS was also involved in the effects of this agent. These protective effects against CCl(4) induced acute liver damage might be through inhibiting lipid peroxidation, inflammatory cytokines, necrosis and apoptosis, and dioscin shows promise for development toward the treatment of acute chemically mediated liver injury.     

Cytotoxicity of dioscin in human gastric carcinoma cells through death receptor and mitochondrial pathways

In the present study, the antiproliferative effect of dioscin on human gastric carcinoma SGC‐7901 cells was confirmed by 3‐(4, 5‐dimethylthiahiazo‐zyl)‐2, 5‐dip‐henytetrazolium bromide and flow cytometry assays. Through acridine orange–ethidium bromide double fluorescent staining, apoptotic morphology of the cells was observed. Radioimmunoassays showed that the tumor necrosis factor (TNF)‐α concentration in cells treated with dioscin significantly increased compared with untreated cells. Several proteins and mRNA related to the mitochondrial and death receptor pathways were investigated. We found that the expression of Bid, bcl‐2 and bcl‐xl was markedly downregulated, and the expression of Bak and Bax was upregulated. In addition, cytochrome c was released from the mitochondria into the cytosol, which indicates activation of the mitrochondrial pathway by dioscin. Furthermore, upregulation of Fas, FasL (Fas ligand), TNF‐α, TNF receptor‐1, TNF receptor‐associated factor 1 and Fas‐associated protein with death domain demonstrated involvement of the death receptor pathway. Increased mRNA expression of p53 was also found in dioscin‐treated SGC‐7901 cells, and the activation of caspase‐3 and ?8 was also observed. Consequently, this study clarifies the mechanism underlying the anticancer effect of dioscin, and also indicates that dioscin may be a potential drug treatment for human gastric cancer. Copyright © 2012 John Wiley & Sons, Ltd.     

Two new alkyl glycosides from Clerodendranthus spicatus.

Two new alkyl glycosides, 3-O-beta-d-apifuranosyl-(1 --> 6)-O-beta-d-glucopyranosyl-(3S)-oct-1-en-3-ol (1, clerspide A) and 3-O-beta-d-apifuranosyl-(1 --> 6)-[beta-d-xylopyranosyl-(1 --> 2)]-O-beta-d-glucopyranosyl-(3S)-oct-1-en-3-ol (2, clerspide B), have been isolated from the whole plants of Clerodendranthus spicatus (Labiatae). Their structures were established on the basis of spectroscopic analyses and chemical method.     

Steroidal saponins from Myriopteron extensum and their cytotoxic activity

Two new steroidal saponins, extensumsides A ( 1) and B ( 2), were isolated from the whole plants of Myriopteron extensum (Wight) K. Schum. Their structures were elucidated as 17 beta-uzarigenin-3- O- beta-glucopyranosyl-(1-->6)- beta-glucopyranosyl-(1-->4)- beta-thevetopyranosyl-(1-->4)- beta-cymaropyranoside ( 1) and 12-(3-methylbut-2-enoyloxy)pregn-5-en-20-one 3- O-[beta-cymaropyranosyl-(1-->4)-beta-cymaropyranosyl-(1-->4)-beta-thevetopyranosyl-(1-->4)-(6- O-sulfo-beta-glucopyranoside)] ( 2) on the basis of chemical and spectral evidence. Extensumside A exhibited significant cytotoxicity against eight cancer cell lines with a mean GI (50) value of 0.346 microg/mL.     

Two new alkyl glycosides from Clerodendranthus spicatus

Two new alkyl glycosides, 3-O-beta-D-apifuranosyl-(1 --> 6)-O-beta-D-glucopyranosyl-(3S)-oct-1-en-3-ol (1, clerspide A) and 3-O-beta-D-apifuranosyl-(1 --> 6)-[beta-D-xylopyranosyl-(1 --> 2)]-O-beta-D-glucopyranosyl-(3S)-oct-1-en-3-ol (2, clerspide B), have been isolated from the whole plants of Clerodendranthus spicatus (Labiatae). Their structures were established on the basis of spectroscopic analyses and chemical method.     

Two new triterpenoid saponins from Sarcandra glabra

Two new triterpenoid saponins, named sarcandroside A and B, have been isolated from Sarcandra glabra (Thunb) Nakai. Their structures have been established as 3beta,19alpha,20beta-trihydroxyurs-11,13 (18)-diene-28,20beta-lactone-3-O-beta-D-glucopyranosyl (1 --> 3)-[alpha-L-rhamnopyranosyl(1 --> 2)]-beta-D-xylopyranoside (1) and 3-O-beta-D-glucopyranosyl (1 --> 3)-[alpha-L-rhamnopyranosyl(1 --> 2)]-beta-D-xylopyranosyl-pomolic acid 28-O-beta-D-glucopyranosyl ester (2) by means of spectral and chemical methods.     

Two new prosapogenins from Albizia adianthifolia

Two new triterpenoidal prosapogenins 1 and 2 were obtained from the mild alkaline hydrolysate of the crude saponin fraction of Albizia adianthifolia (Mimosaceae) roots. Their structures were mainly determined by spectral analyses as acacic acid 3-O-beta-D-xylopyranosyl-(1-->2)-beta-D-fucopyranosyl-(1-->6)- 2-acetylamino-2-deoxy-beta-D-glucopyranoside (1) and acacic acid 3-O-(beta-D-xylopyranosyl-(1-->2)-beta-D-fucopyranosyl-(1-->6)- [beta-D-glucopyranosyl-(1-->2)]-beta-D-glucopyranosyl)-21-O-(6(S)-2- hydroxymethyl-6-methyl-6-O-(beta-D-quinovopyranosyl)-2,7-octadienoyl) ester (2). Furthermore, the known julibroside A3 was isolated from the crude saponin mixture. Compounds 1 and 2 did not show any ability to potentiate in vitro cisplatin cytotoxicity in a human colon cancer cell line.     

Dioscin-induced autophagy mitigates cell apoptosis through modulation of PI3K/Akt and ERK and JNK signaling pathways in human lung cancer cell lines

Our previous study has revealed that dioscin, a compound with anti-inflammatory, lipid-lowering, anticancer and hepatoprotective effects, may induce autophagy in hepatoma cells. Autophagy is a lysosomal degradation pathway that is essential for cell survival and tissue homeostasis. In this study, the role of autophagy and related signaling pathways during dioscin-induced apoptosis in human lung cancer cells was investigated. Results from 4′-6-diamidino-2-phenylindole and annexin-V/PI double-staining assay showed that caspase-3- and caspase-8-dependent, and dose-dependent apoptoses were detected after a 24-h dioscin treatment. Meanwhile, autophagy was detected as early as 12 h after an exposure to low-dose dioscin, as indicated by an up-regulated expression of LC3-II and beclin-1 proteins. Blockade of autophagy with bafilomycin A1 or 3-methyladenine sensitized the A549 and H1299 cells to apoptosis. Treatment of A549 and H1299 cells with dioscin caused a dose-dependent increase in ERK1/2 and JNK1/2 activity, accompanied with a decreased PI3K expression and decreased phosphorylation of Akt and mTOR. Taken together, this study demonstrated for the first time that autophagy occurred earlier than apoptosis during dioscin-induced human lung cancer cell line apoptosis. Dioscin-induced autophagy via ERK1/2 and JNK1/2 pathways may provide a protective mechanism for cell survival against dioscin-induced apoptosis to act as a cytoprotective reaction.     

薯蓣属植物化学成分的研究——Ⅹ.蜀葵叶薯蓣中甾体皂甙和皂甙元的分离和鉴定

Four components were isolated from acid-treated rhizome of Dioscorea althaeoides Kunth. Their structures were identified as diosgenin (Ⅰ), β-sitosterol (Ⅱ), diosgenin palmitate (Ⅲ) and △^3,5-deoxytigogenin (Ⅳ) on the basis of physical constants and spectral data.Two sparingly soluble steroid saponins were also isolated from this plant Their physicochemical constants showed that one of them is dioscin (Ⅴ) and the other graeillin (Ⅵ).     

Dioscin reduces lipopolysaccharide-induced inflammatory liver injury via regulating TLR4/MyD88 signal pathway

We previously reported the effects of dioscin against carbon tetrachloride-, acetaminophen- and alcohol-induced acute liver damage. However, its effect on lipopolysaccharide (LPS)-induced inflammatory liver injury remains unknown. In the present work, liver injury in mice and rats was induced by LPS, and dioscin was intragastrically administered for 7 days. In vitro, the AML-12 cells and HepG-2 cells were treated with LPS after dioscin treatment. The results showed that dioscin not only markedly reduced serum ALT, AST levels and relative liver weights, but also restored cell injury caused by LPS. In mechanism study, dioscin significantly attenuated inflammation through down-regulating the levels of toll-like receptor (TLR) 4, myeloid differentiation factor 88 (MyD88), interleukin-1 receptor-associated kinase 1 (IRAK1), tumor necrosis factor receptor-associated factor 6 (TRAF6), phosphorylated inhibitor of nuclear factor κB kinase (p-IKK), phosphorylated inhibitor of nuclear factor κB alpha (p-IκBα), phosphorylated nuclear factor κB p65 (p-NF-κB p65), high-mobility group protein 1 (HMGB-1), interleukin (IL)-1, IL-6 and tumor necrosis factor-α (TNF-α). TLR4 overexpression was also decreased by dioscin, leading to the markedly decreased levels of MyD88, IRAK1, TRAF6, p-IKK, p-IκBα, p-NF-κB p65 and HMGB-1. Suppression of MyD88 by ST2825 eliminated the inhibitory effects of dioscin on the levels of IRAK1, TRAF6, p-IKK, p-IκBα, p-NF-κB p65, HMGB-1, IL-1β, IL-6 and TNF-α. Our results suggested that dioscin exhibited protective effect against LPS-induced liver injury via altering TLR4/MyD88 pathway, which should be developed as one potent candidate for the treatment of acute inflammatory liver injury in the future.     

Pregnane glycosides from Dracaena cochinchinensis

Two new pregnane glycosides, named dracaenoside C and D, were isolated from the fresh stems of Dracaena cochinchinensis. Their structures were established as 3beta,14alpha-dihydroxypregna-5,16(17)-diene-20-one 3-O-alpha-L-rhamnopyranosyl(1 --> 2)[alpha-L-rhamnopyranosyl(1 --> 4)]-beta-D-glucopyranoside (1) and 3beta,14alpha-dihydroxypregna-5,16(17)-diene-20-one 3-O-alpha-L-rhamnopyranosyl(1 --> 2)[beta-D-glucopyranosyl(1 --> 3)]-beta-D-glucopyranoside (2) by means of 2D NMR spectral and chemical methods.