C21 Steroidal Glycoside Research Articles

Therapeutic potential of CB1R activation by Qingyangshen glycoside M1 for seizure relief

Ethnopharmacological relevanceCynanchum otophyllum C.K.Schneid.PI.Wilson, commonly referred as ‘‘Qingyangshen’’ (QYS), is a traditional folk medicine from Yunnan, renowned for its efficacy in neurological and psychiatric disorders. Glycosides isolated from QYS have shown promise in alleviating epilepsy, however, mechanisms of action and specific molecular targets remain to be elucidated. Aim of the studyThe study aimed to evaluate the anticonvulsant effects of Qingyangshen glycosides M1 (M1), a C21 steroidal glycoside from QYS, on pentylenetetrazol (PTZ)-induced convulsions in zebrafish (Danio rerio), and its neuroprotective effect on Glutamate (Glu)-induced damage to PC12 cells, and importantly to identify its potential molecular targets. Materials and methodsTo evaluate anticonvulsant activity of M1, 7 days-post-fertilization (7-dpf) animals were pretreated (by immersion) and then exposed to PTZ (10 mM) solution. Furthermore, Glu-induced PC12 cell damage was employed to investigate the neuroprotective and anti-apoptotic capacity. Cells were pretreated with various concentrations of M1 (0–10 μM) for 12 h and then co-treated with Glu (15 mM) for an additional 24 h. The cell viability, apoptosis rate and apoptosis-related proteins (p-PI3K, PI3K, Akt, p-Akt, CREB, p-CREB, BDNF, Bax and Bcl-2) were measured using CCK-8, annexin V/PI and Western blot assays. To model the expected interaction between M1 and candidate cannabinoid receptor type 1 (CB1R), ERK phosphorylation, molecular docking, and drug affinity responsive target stability (DARTS) techniques were employed. Finally, CB1R antagonist Rimonabant (Rim) was validated by co-administration in both zebrafish and cells to confirm the requirement of CB1R for M1 efficacy. ResultsAt a concentration of 400 μM, M1 dramatically reversed PTZ-induced convulsive-like behaviors in zebrafish, as evidenced by a significant reduction in locomotor activity. In the context of Glu-induced cytotoxicity, M1 (10 μM) demonstrated a notable increase in cell viability and suppressed apoptosis through modulation of the Bax/Bcl-2 ratio and activation of the PI3K/Akt/CREB/BDNF signaling axis. These effects were facilitated through CB1R activation. In contrast, Rim dampened the beneficial activities of M1 as a cannabinoid agonist. ConclusionsThese results demonstrated that M1 as a potential CB1R activator, exhibiting anticonvulsive effects in a PTZ-induced zebrafish model and neuroprotective properties via the PI3K/Akt/CREB/BDNF signaling axis in a Glu-induced PC12 cell injury model. Notably, the observed seizure relief attenuated by CB1R chemical antagonism.

Chemical constituents from Potentilla kleiniana and their chemotaxonomic significance

Phytochemical study of Potentilla kleiniana gave one C21 steroidal glycoside (1), seven ellagic acid derivatives (2–8), five flavonoids (9–13), one alkaloid (14), one nucleoside (15), one aromatic aldehyde (16), one aromatic ketone (17), one phenylacetic acid derivative (18), one phenolic acid (19), one phenolic acid derivative (20), and one dehydrodiconiferyl alcohol derivative (21). The chemical structures of these compounds were elucidated based on spectroscopic methods and comparison with reported data. Among them, compound 1 was a new compound, and compounds 3–4, 7–18, 20–21 were first reported from this plant. Moreover, the chemotaxonomic significance of the isolated compounds from the whole plants of P. kleiniana has been discussed in detail.

Anti-cancer activity of Marsdenialongise A, a new C21 steroidal glycoside isolated from Marsdenia longipes W.T. Wang (Apocynaceae)

C21 steroidal glycosides are a group of natural compounds with biological activities such as anti-cancer, anti-microbial, and anti-viral properties. In this study, we isolated and determined the structure of a new C21 steroidal glycoside, named Marsdenialongise A from Marsdenia longipes W.T. Wang, using nuclear magnetic resonance spectroscopy and mass spectra data. Marsdenialongise A is a derivative of tenacigenin B and was isolated for the first time from a plant. The inhibitory effect of Marsdenialongise A on cancer cells was evaluated through MTT and cell migration assays, cell cycle, and apoptosis analyses. The results of the MTT assay showed that Marsdenialongise A reduces the cell viability of cancer cells, with the AGS cell line being more sensitive than other cell lines, with an IC50 value of 5.69 µM (for 48 h of treatment). Marsdenialongise A also exhibited an ability to prevent the migration of cancer cells in AGS cells. Further analysis using flow cytometry has revealed that Marsdenialongise A is capable of inducing cell cycle arrest and apoptosis. The overexpression of reactive oxygen species (ROS) production induced by Marsdenialongise A can be considered a cause that leads to the influence on the cell cycle and apoptosis of cancer cells. Thus, Marsdenialongise A can be considered a potential anti-cancer agent.

Effect of C21 steroidal glycoside of Cynanchum auriculatum on liver and kidney fibrosis through TLR4 pathway

The liver and kidney fibrosis model was established by thioacetamide(TAA) and unilateral ureteral obstruction(UUO) in SD rats. The rats were randomly divided into three groups: model group, low and high-dose groups of C21 steroidal glycosides of Cynanchum auriculatum. Another blank control group was set. Four weeks later, serum was taken to detect the biochemical indexes of liver and kidney function. Urine protein and urine creatinine were detected by kits. Liver and kidney tissue samples were stained with HE and Masson staining, and hydroxyproline content was detected. Western blot was used to detect expressions of fibrotic proteins, inflammatory factors and TLR4 signaling pathways, so as to observe the preventive and therapeutic effects of C21 steroidal glycosides from C. auriculatum on hepatic and renal fibrosis and explore its molecular mechanism. Four weeks later, serum biochemical results showed that liver and kidney functions were seriously damaged, and pathological sections showed that inflammatory cell infiltration, decrease of parenchymal cells, and increase of interstitial fibrosis in liver and kidney tissues. The results showed that low and high doses(150, 300 mg·kg~(-1)) of C21 steroidal glycosides could significantly reduce the collagen deposition and the pathological changes of liver and kidney fibrosis compared with the model group. At the same time, we found that the expression levels of TLR4 and MyD88 signaling pathway proteins were significantly increased in the liver and kidney tissues of the model group, and a large number of NF-κB signaling pathway proteins migrated into the nucleus. On the contrary, the expression levels of TLR4, MyD88 signaling pathway proteins and the nuclear migration of NF-κB were significantly inhibited in the low and high dose groups of C21 steroidal glycosides from C. auriculatum. Therefore, it was speculated that the mechanism of C21 steroidal glycoside for preventive and therapeutic effect on hepatic and renal fibrosis was related to inhibit TLR4/MYD88/NF-κB inflammatory pathway, thus preventing hepatic and renal fibrosis.

Characterization of chemical components of Periplocae Cortex and their metabolites in rats using ultra‐performance liquid chromatography coupled with quadrupole time‐of‐flight mass spectrometry

Periplocae Cortex, named Xiang-Jia-Pi in China, has been widely used to treat autoimmune diseases, especially rheumatoid arthritis. However, the in vivo substances of Periplocae Cortex remain unknown yet. In this study, an ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry was used for profiling the chemical components and related metabolites of Periplocae Cortex. A total of 98 constituents were identified or tentatively characterized in Periplocae Cortex: 42 C21 steroidal glycosides, 10 cardiac glycosides, 23 organic acids, 4 aldehydes, 7 triterpenes, and 12 other types. Among them, 18 components were unambiguously identified by comparison with reference standards. In addition, 176 related xenobiotics (34 prototypes and 142 metabolites) were screened out and characterized in rats' biosamples (plasma, urine, bile, and feces) after the oral administration of Periplocae Cortex. Moreover, the metabolic fate of periplocoside S-4a, a C21 steroidal glycoside, was proposed for the first time. In summary, phase II reactions (methylation, glucuronidation, and sulfation), phase I reactions (hydrolysis reactions, oxygenation, and reduction), and their combinations were the predominant metabolic reactions of Periplocae Cortex in rat. It is the first report to reveal the in vivo substances and metabolism feature of Periplocae Cortex. This study also provided meaningful information for further pharmacodynamics study of Periplocae Cortex, as well as its quality control research.

A C21-Steroidal Glycoside from Cynanchum atratum Attenuates Concanavalin A-Induced Liver Injury in Mice.

Cynatratoside A (CyA) is a C21 Steroidal glycoside with pregnane skeleton isolated from the root of Cynanchum atratum Bunge (Asclepiadaceae). This study aimed to investigate the effects of CyA on concanavalin A (Con A)-induced autoimmune hepatitis (AIH) and the underlying mechanism. CyA was orally administered to mice at 10 and 40 mg/kg 8 h before and 1 h after Con A treatment. The effects of CyA on Con A-induced spleen and liver in mice were assessed via histopathological changes, T lymphocyte amounts and the expressions of IL-1β and ICAM-1. Con A-induced L-02 hepatocytes were used to evaluate whether CyA (0.1–10 μM) can directly protect hepatocytes from cytotoxicity and the possible mechanism. The results revealed that CyA treatment could significantly improve the histopathological changes of spleen and liver, reduce the proliferation of splenic T lymphocytes, and decrease the expressions of IL-1β and ICAM-1 in liver. The experiment in vitro showed that CyA inhibited Con A-induced hepatotoxicity in a concentration-dependent manner. CyA (10 μM) significantly increased/decreased the expression of Bcl-2/Bax and reduced the levels of cleaved caspases-9 and -3. Our study demonstrated for the first time that CyA has a significant protective effect on Con A-induced AIH by inhibiting the activation and adhesion of T lymphocytes and blocking hepatocyte apoptosis.

New transformation pathway and cytotoxic derivatives from the acid hydrolysis of timosaponin B III

Timosaponin B III is a major bioactive steroidal saponin isolated from Anemarrhena asphodeloides Bge. To potentially discover derivatives with better biological activity, timosaponin B III was structurally modified via acid hydrolysis to yield one new (2, timopregnane A I) C21 steroidal glycoside and seven known compounds. Their structures were elucidated on the basis of NMR spectroscopy and mass spectrometry. All eight compounds were evaluated for cytotoxic activity against MCF7, SW480, HepG2, and SGC7901 cell lines in vitro. As a result, compounds 6 and 7 showed significant activity (IC50 2.94–12.2 μM) against all tested cell lines. Structure–activity relationships of these compounds were investigated and the preliminary conclusions were provided. Moreover, a new transformation pathway was discovered in the acid hydrolysis of timosaponin B III for the first time.

New C21 steroidal glycosides from the roots of Cynanchum stauntonii and their protective effects on hypoxia/reoxygenation induced cardiomyocyte injury

Phytochemical investigations from the roots of Cynanchum stauntonii led to obtain four new C21 steroidal glycosides (1–4) and one known compound stauntoside F (5). Their chemical structures were characterized by sophisticated analyses of IR, HRESI-TOF-MS, 1D, and 2D-NMR data, together with chemical methods, which showed interesting 13,14:14,15-disecopregnane-type skeleton or 14,15-secopregnane-type skeleton C21 steroidal glycosides. Among them, compound 1 was determined to be glaucogenin C 3-O-β-d-glucopyranosyl-(1→4)-β-d-cymaropyranosyl-(1→4)-β-d-digitoxopyranosyl-(1→4)-β-d-thevetopyranoside. Compound 2 was characterized to be hirundigenin 3-O-α-l-diginopyranosyl-(1→4)-β-d-cymaropyranosyl-(1→4)-β-d-digitoxopyranosyl-(1→4)-β-d-3′-demethyl-thevetopyranoside. Compound 3 was identified to be (14S,16S,20R)-14,16-14,20-15,20-triepoxy-14,15-secopregn-5-en-3-ol-3-O-α-l-cymaropyranosyl-(1→4)-β-d-digitoxopyranosyl-(1→4)-β-d-oleandropyranoside. Compound 4 was identified to be (14S,16S,20R)-14,16-14,20-15,20-triepoxy-14,15-secopregn-5-en-3-ol-3-O-α-l-cymaropyranosyl-(1→4)-β-d-cymaropyranosyl-(1→4)-β-d-digitoxopyranosyl-(1→4)-β-d-thevetopyranoside. Among them, compound 2 was hirundigenin type C21 steroidal glycoside that existed in nature as epimers due to the presence of 14-hemiketal hydroxyl group in its structure. In addition, the anti-inflammatory and cardiomyocyte protective effects of compounds 1–4 were evaluated. We found that they exhibited significant protective effects on hypoxia/reoxygenation induced cardiomyocyte injury, but did not showed obvious anti-inflammatory function.

Paniculatumoside G, a new C21 steroidal glycoside from Cynanchum paniculatum

A new C21 steroidal glycoside, paniculatumoside G, together with neocynapanogenin C isolated for the first time from the natural source and two known compounds were isolated and characterized from the roots and rhizomes of Cynanchum paniculatum (Bunge) Kitag. ex H.Hara, Apocynaceae, a commonly used Traditional Chinese Medicine. On the basis of spectroscopic analysis, including HR-ESI-MS, 1D and 2D NMR spectral data, the structure of the new C21 steroidal glycoside was elucidated as neocynapanogenin H 3-O-β-d-oleandropyranoside.

Asclepiasterol, a novel C21 steroidal glycoside derived from Asclepias curassavica, reverses tumor multidrug resistance by down-regulating P-glycoprotein expression.

Multidrug resistance (MDR) mediated by P-glycoprotein (P-gp) is a major cause of cancer therapy failure. In this study, we identified a novel C21 steroidal glycoside, asclepiasterol, capable of reversing P-gp-mediated MDR. Asclepiasterol (2.5 and 5.0μM) enhanced the cytotoxity of P-gp substrate anticancer drugs in MCF-7/ADR and HepG-2/ADM cells. MDR cells were more responsive to paclitaxel in the presence of asclepiasterol, and colony formation of MDR cells was only reduced upon treatment with a combination of asclepiasterol and doxorubicin. Consistent with these findings, asclepiasterol treatment increased the intracellular accumulation of doxorubicin and rhodamine 123 (Rh123) in MDR cells. Asclepiasterol decreased expression of P-gp protein without stimulating or suppressing MDR1 mRNA levels. Asclepiasterol-mediated P-gp suppression caused inhibition of ERK1/2 phosphorylation in two MDR cell types, and EGF, an activator of the MAPK/ERK pathway, reversed the P-gp down-regulation, implicating the MAPK/ERK pathway in asclepiasterol-mediated P-gp down-regulation. These results suggest that asclepiasterol could be developed as a modulator for reversing P-gp-mediated MDR in P-gp-overexpressing cancer variants.

Two new glycosides and one new neolignan from the roots of Cynanchum stauntonii

Three new compounds including one C21-steroidal glycoside, one methylglycoside, and one neolignan, named as Deoxyamplexicogenin A-3-O-yl-4-O-(4-O-α-l-cymaropyranosoyl-β-d-digitoxopyranosoyl)-β-d-canaropyranoside (1), Methyl-O-α-l-cymaropyranosoyl-(1→4)-β-D-digitoxopyranoside (2), and (+)-(7S, 8R, 7′E)-5-hydroxy-3, 5′-dimethoxy-4′, 7-epoxy-8, 3′-neolign-7′-ene-9, 9′-diol 9′-ethyl ether (3), respectively, were isolated from the roots of Cynanchum stauntonii. The structure elucidations were achieved by in-depth spectroscopic examination, mainly including the experiments and analyses of multiple 1D- and 2D-NMR and HRESIMS and CD analysis and qualitative chemical tests. Cytotoxicity activities of compounds 1–3 were evaluated against five tumor cell lines (HCT-8, Bel-7402, BGC-823, A549, and A2780) in cell based assays where they were found to be inactive.

Antitumor Effect of C21 Steroidal Glycosides on Adenoid Cystic Carcinoma Cell Line SACC83.

To observe the anti-tumor effects and possible mechanism of C21 steroidal glycoside (17-β-Marsdenia tenacissima glycoside B (17-β-tenacigenin B)) and Xiaoaiping injection in the adenoid cystic carcinoma cell line SACC83. We used the salivary adenoid cystic carcinoma cell line SACC83 for the study and used MTT, flow cytometry, and Western-blot (WB) to study the anti-tumor efficacy and mechanism of 17-β-tenacigenin B and Xiaoaiping injection. Three groups were divided as follows: group 1: control group (without drug treatment), group 2: SACC83 treated with 17-β-Marsdenia tenacissima glycoside B, group 3: SACC83 treated with Xiaoaiping injec- tion. The 17-β-tenacigenin B had no significant anti-tumor effect while the Xiaoaiping injection had a dosage-dependent growth inhibition effect on the adenoid cystic carcinoma cell line SACC83. According to WB, after the administration of the 17-p-tenacigenin B, the expression of apoptosis-related protein was not very significant; however, after the administration of the Xiaoaiping injection, the expression of apoptosis inhibition protein bcl-2 decreased while the expression of apoptosis promotion protein bax increased. The 17-β-tenacigenin B had no obvious anti-tumor effects while the Xiaoaiping injection had good anti-tumor effects. Even though the 17-β-tenacigenin B is an important component of the Xiaoaiping injection, in the in vitro experiment, compared with the Xiaoaiping injection, the 17-β-tenacigenin B showed no good anti-tumor effects. However, we need further studies on in vivo experiments of 17-β-tenacigenin B and the anti-tumor effect of other C21 steroidal glycoside monomers in the Xiaoaiping injection.

Cytotoxic and apoptosis-inducing properties of a C21-steroidal glycoside isolated from the roots of Cynanchum auriculatum

The present study aimed to investigate the anti-cancer effect of a C21-steroidal glycoside (CG) isolated from the roots of Cynanchum auriculatum. CG was able to inhibit the growth of human cancer cells (SGC-7901 cells) in a concentration and time-dependent manner in vitro. SGC-7901 cells exposed to CG (10.8 and 21.6 μM) exhibited typical morphological apoptosis characteristics, such as nuclear-chromatin condensation and apoptotic body formation. Flow cytometric analysis showed that after treatment with CG at 10.8 and 21.6 μM for 24 h, the percentage of apoptotic cells increased to 30.4 and 43.2%, respectively, while the number of cells in the G0/G1, S and G2/M phases of the cell cycle decreased (P<0.05). Furthermore, treatment with CG at a concentration of 21.6 μM for 24 h significantly increased the expression of caspase-3 and the activity of caspase-3 was increased ∼3-fold in SGC-7901 cells. These results suggest that CG is the active anticancer component of the total C21-glycosides of the roots of Cynanchum auriculatum which is able to inhibit the growth of cancer cells and induce cancer cell apoptosis through caspase-3-dependent pathways.

Steroidal glycosides from Cynanchum amplexicaule

A new C21 steroidal glycoside that has a new steroid amplexicogenin C as aglycone, together with three known steroids, were isolated from Cynanchum amplexicaule. Their structures were elucidated as amplexicogenin C-3-O-β-D-cymaropyranoside (1), cynatratoside A (2), tylophoside A (3), and cynatratoside B (4) by spectroscopic methods, including 1D and 2D NMR experiments.

Steroids and Related Compounds: Basic and Clinical Aspects

The steroid hormones generate myriad effects through several well-known mechanisms of action. Beyond the physiological function of steroid hormones, the steroid-like effects of some natural and synthetic compounds have led to the promising field of alternative therapies. However, to these new compounds, the molecular, subcellular, and cellular signal transductions need to be elucidated. Although new questions about the relevance of multiple targets of action for exogenous compounds are deeply in discussion, the original contributions that depict novel insights into basic and clinical aspects with perspectives on medical application are welcome. This special issue compiles papers from renowned research groups in the world that cover the frontiers of the latest findings on steroids and related compounds effect, mechanism of action and its relevance on carcinogenesis, immune suppression, and osteoporosis, as well as novel steroidal glycosides characterization. The papers on sex steroids hormones review the role of progesterone (precursor for androgens and estrogens produced by the gonadal and adrenal cortical tissues) and related progestins compounds in hepatocellular carcinoma. The authors highlight that the higher incidence of hepatocellular carcinoma in men than women might have resulted from the stimulatory effects of androgen and the protective effects of estrogen and also eventually suggest a new insight into the associations of progesterone and related compounds with hepatocellular carcinoma development and treatment. Also, the sex steroid hormones in the modulation of bacterial-host interactions were revised since the dimorphic sex difference (low immune responses presented in males as compared to females) is mainly due to the differential modulation of the immune system by sex steroid hormones through the control of proinflammatory and anti-inflammatory cytokines expression, as well as Toll-like receptors expression and antibody production. Some interesting studiesonhumans addressed the effect of chronic glucocorticoid therapy on osteoporosis in children with 21-hydroxylase deficiency as much to replace congenital deficits in cortisol synthesis as to reduce androgen secretion by adrenal cortex. As consequence, a secondary osteoporosis is formed. It results in an early, transient increase in bone resorption accompanied by decrease in bone formation, maintained for the duration of glucocorticoid therapy. Based on conflicting results from the literature about the bone status on glucocorticoid-treated patients with 21-hydroxylase deficiency, the authors point that the monitoring of the bone status of these patients, checking bone mineral density and bone turnover markers, and studying the expression of regulators of bone resorption should be useful in order to avoid glucocorticoid-induced osteoporosis in adulthood. Also, based on many epidemiological studies concerning the inverse relationship between isoflavone intake and bone loss and fracture rate, some substances on serum levels after food intake indicated for patients with osteopenia/osteoporosis were analyzed. Concerning genistein bioavailability, it was deeply discussed that, beyond the intestinal bacteria, solubility and permeability, glucosidase activity, viscosity induced by food additives, and a multitude of transporters on luminal intestinal cells for absorption, several factors from the diet composition influence the net absorption of single entity and also the effectiveness of the bone build. So, with these data in mind, the bioavailability of genistein depends on specific ingredients and excipients in each formulation which can interfere with absorption and could have clinical implications on efficacy. The ongoing investigations of some groups in the world have characterized new steroidal compounds from plants with medicinal interest. Three new steroidal glycosides, named as stauntosides L, M, and N, along with one known C21 steroidal glycoside, anhydrohirundigenin monothevetoside, were isolated from the roots of Cynanchum stauntonii (Decne.) and extensively evaluated by spectroscopic analyses, mainly 1D and 2D NMR, HRESI-MS and chemical methods. It is known that C21 steroids and their glycosides are of considerable bioactivities, such as hypolipidemic and antitumor activity. So the enriched information about C. stauntonii as a significant source of steroidal glycosides deserves careful phytochemistry investigation as well as the classification of bioactive compounds to be proposed as nutraceutical agents interesting both to academy and industry and also to specific therapy option.

Three New Steroidal Glycosides from the Roots ofCynanchum stauntonii

Three new steroidal glycosides, named as stauntosides L, M, and N (1–3), along with one known C21 steroidal glycoside, anhydrohirundigenin monothevetoside (4), were isolated from the 95% ethanol extract of the roots of Cynanchum stauntonii. The structures of these new compounds were elucidated on the basis of extensive spectroscopic analyses, mainly 1D and 2D NMR, HRESI-MS, and chemical methods.

Polyhydroxylated Steroidal Glycosides from Paris polyphylla

Three new steroidal saponins, parisyunnanosides G-I (1-3), one new C(21) steroidal glycoside, parisyunnanoside J (4), and three known compounds, padelaoside B (5), pinnatasterone (6), and 20-hydroxyecdyson (7), were isolated from the rhizomes of Paris polyphylla Smith var. yunnanensis. Compounds 1 and 3 have unique trisdesmoside structures that include a C-21 β-d-galactopyranose moiety. All compounds were evaluated for their cytotoxicity against human CCRF leukemia cells.

Optimization of the hydrolysis process for C21 steroidal glycoside of Bai Shou Wu by acetic acid with multi-target orthogonal design

To study the optimizal hydrolysis process for C21 steroidal glycoside of Bai Shou Wu by acetic acid. The effects of acetic acid concentration, reaction temperature and reaction time had been investigated using orthogonal design and the contents of kidjoranin 3-O-beta-digitoxopyranoside, caudatin, kidjoranin 3-O-alpha-L-diginopyranosyl-(1 --> 4)-beta-cymaropyranoside and caudatin 3-O-beta-cymaropyranoside as response indexs were determined by the high performance liquid chromatography. The factors influencing acetic extraction efficiency were as follows: A > B > C (A. reaction temperature; B. reaction time; C. acetic acid concentration). The optimal hydrolysis condition obtained was: refluxing for 6 hours with 5.0% dilute CH3COOH solution at 100 degrees C. The content of antitumor active ingredients under the optimum hydrolysis condition is raised obviously and has a great part in studying this antitumor drug.

Antitumor effects by Wilfoside C3N treatment in ECA109 cells

C21 steroidal glycoside (C21) is one of the most bioactive compounds of Cynanchum auriculatum Royle, known as Baishouwu, and possesses potent antitumor activity. Wilfoside C3N is one of the two most abundant and active C21 in it. The aim of this study was to further investigate the antitumor activity of C3N and to clarify its signaling pathway. The growth inhibition ofECA109 cells induced by C3N was assessed. Western blot analysis, reverse-transcription PCR, caspase-2 and Fas activity assay, and knockdown of caspase-2 with siRNA were used to study the apoptotic mechanisms. We showed that C3N inhibited the proliferation of ECA109 cells moderately in a dose and time-dependent manner and induced apoptosis in the ECA109 cell line through a mitochondrial pathway by triggered cytochrome c release from the mitochondria, with caspase-2 functioning upstream of caspase-9 rather than association with Fas and caspase-8. Furthermore, C3N-driven apoptotic events were associated with downregulation of Bcl-2. These results suggest that C3N-induced apoptosis of ECA109 cells in vitro was dependent on caspase-2 or mitochondria or caspase-9 and independent of the Fas-FasL or caspase-8 pathway.

A new C21 steroidal glycoside from Cynanchum inamoenum (Maxim.) Loes

A new C21 steroidal glycoside, 5β,6β-epoxy-glaucogenin C-3-O-β-d-glucopyranosyl-(1 → 4)-β-d-glucopyranosyl-(1 → 4)-β-d-cymaropyranosyl-(1 → 4)-β-d-oleandropyranosyl-(1 → 4)-β-d-oleandropyranoside, named inamoside D (1), was isolated from the MeOH extract of the roots of Cynanchum inamoenum (Maxim.) Loes (Asclepiadaceae). In addition, five known compounds, including 7-demethoxytylophorine (2), dehydrodiconiferyl alcohol γ′-O-β-d-glucopyranoside (3), β-d-fructofuranosyl-(2 → 1)-α-d-(6-O-sinapoyl)-glucopyranoside (4), neohancoside C (5), and cuchiloside (6), have also been isolated. The structure of 1 was determined by 1D- and 2D-NMR spectroscopies. All the compounds were isolated from this plant for the first time.