Furospirostanol and spirostanol saponins from the rhizome of Tupistra chinensis and their cytotoxic and anti-inflammatory activities

TCP80-1, a new levan-neoseries fructan from Tupistra chinensis Baker rhizomes alleviates ulcerative colitis induced by dextran sulfate sodium in Drosophila melanogaster model

Ulcerative colitis (UC) is a recurrent inflammation of the gastrointestinal tract, for which available treatment drugs are severely limited. Natural polysaccharides show potential for UC prevention. Herein, we extracted TCP80-1, a polysaccharide with significant anti-ulcerative colitis (UC) activity, from Tupistra chinensis Baker for the first time. Structure analysis revealed that TCP80-1 (3190 Da) was a levan-neoseries fructan containing → 6)-α-D-Glcp-(1→, →1)-β-D-Fruf-(2→, →1,6)-β-D-Fruf-(2→, →6)-β-D-Fruf-(2→ and β-D-Fruf-(2→ residues as backbone, with →6)-β-D-Fruf-(2→, and β-D-Fruf-(2→ as side chains substituted at C-6. The protective effect of TCP80-1 on UC was further evaluated using a UC Drosophila melanogaster model. The results demonstrated that TCP80-1 could alleviate the UC symptoms by reducing colonic atrophy, enhancing intestinal barrier, and promoting the proliferation and differentiation of intestinal stem cells (ISCs) into intestinal epithelial cells (IECs). Our findings provide important structural information about TCP80-1 and establish the foundation for the future progression and utilization of T. chinensis polysaccharide within the realm of UC therapy.

Steroidal saponins profiling of Rohdea chinensis (Baker) N.Tanaka by high performance liquid chromatography coupled to electrospray ionization and quadrupole time-of-flight mass spectrometry

The rhizome of Rohdea chinensis (Baker) N.Tanaka (RRc) is a famous folk medicine for the treatment of carbuncles and pharyngitis. Steroidal saponins (SSs) were considered to be the most abundant active constituents in RRc. However, to date, the in-depth study of SSs is still lacking. This study was aimed to investigate the SSs profiles of RRc extract by HPLC-ESI-QTOF-MS/MS. Analysis was performed on an Agilent poroshell 120 EC-C18 column (2.1 mm × 100 mm, i.d., 2.7 μm) with 0.1% formic acid aqueous solution and acetonitrile as the mobile phase under gradient conditions. The results showed that 32 SSs including 20 furospirostanol, 11 spirostanol and 1 pseudo-spirostanol saponins were identified, 5 of which were reported in this plant for the first time. This is the first report on the analysis of SSs in RRc. This novel analysis method may stimulate further research regarding the identification of SSs in other plant species.

Steriodal saponins from the rhizomes of Tupistra chinensis Baker

Chemical constituent investigation on the n-BuOH extract of the rhizomes of Tupistra chinensis Baker leads to the isolation of ten compounds including eight undescribed furostanol saponins, tupischinosides A - H, and two known ones. The structures of isolated compounds were determined by extensive spectral analysis and chemical evidences. Interestingly, tupischinosides A and B, C and D, E and F, G and H were identified as four pairs of epimers. The cytotoxicity of tupischinosides A - H against human cancer cell lines U87, SHG44, U251, LN229 and HepG-2 was evaluated by CCK-8 method. As a result, tupischinosides A and C exhibited significant proliferation inhibitory effect on the tested cancer cells. On the contrary, the corresponding epimers, tupischinosides B and D, which only differ in the configuration of C-23 didn't exhibit any cytotoxicity to cancer cells. These results indicated that the stereochemistry of C-23 was crucial to the activity of the compounds.

Three New Steriodal Saponins from the Rhizomes of Tupistra chinensis Baker

The phytochemical constituent investigation on the 70 % ethanol extract of the rhizomes of Tupistra chinensis Baker resulted in the isolation of three new steroidal saponins which were named tuchinosides A-C (1-3). Their structures were determined by extensive spectrum analysis and chemical evidence, especially 2D NMR and HR-ESI-MS techniques. In addition, the cytotoxicity of compounds 1-3 against several human cancer cell lines was evaluated.

Two new steroidal sapogenins from Rohdea chinensis (synonym Tupistra chinensis) rhizomes and their antifungal activity

Two novel acylated steroidal sapogenins, 3β-acetoxy-1α, 2α, 4β, 5α, 7α-pentahydroxy-spirost-25(27)-en-6-one (1) and (25S)-3α-acetoxy-1α, 2β, 4α, 5α, 7α-pentahydroxyspirostan-6-one (2), together with two known steroidal sapogenins (3 and 4), were isolated from Rohdea chinensis rhizomes. Their structures were elucidated by nuclear magnetic resonance (NMR) and mass spectrometry (MS) data. In addition, the antifungal activities of the isolated compounds against Penicillium digitatum and Rhizopus stolonifera were evaluated. Compound 2 significantly inhibited R. stolonifera growth, which was comparable to the positive control (sodium benzoate and carbendazim). Compound 4 showed the highest potency to inhibit P. digitatum growth compared to other compounds.

Genus Tupistra: A Comprehensive Review of Phytochemistry and Pharmacological Activity

In the current paper, secondary metabolites separated from Tupistra plants have been reviewed. Approximately 200 phytochemicals, classified in various chemical classes of bioactive compounds, have been compiled, along with their sources and references. The most striking feature is that the most frequently isolated compounds have been spirostanol sapogenins, and spirostanol and furostanol saponins, most of which are new in nature. The application of both Tupistra plant extracts and isolated compounds in biological assays is also one of the crucial aims in pharmacological discoveries. Tupistra constituents have demonstrated valuable properties in the field of pharmacology, such as antioxidative, antimicrobial, antidiabetic, and antihepatic activities, but their cytotoxic and anti-inflammatory actions can be considered as the more remarkable. In vivo cancer-related activities of the tested Tupistra samples were mostly based on apoptosis. Further phytochemical investigations, together with extensive assessments of the biological profiles and mechanism of action studies of the components of Tupistra species are to be expected.

Total saponins from Tupistra chinensis baker inhibits growth of human gastric cancer cells in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Tupistra chinensis Baker (syn. Rohdea chinensis), an antitumor folk herb mainly distributed in China, its rhizome has been historically used to treat gastric cancer. Studies showed that the steroidal saponins were the main bioactive components in the rhizome of T. chinensis. Our previous studies have confirmed that the steroidal saponins have a variety of anti-tumor activities. However, the underlying anti-tumor mechanism of the total steroidal saponins of T. chinensis (TCS) remains to be revealed.

AIM OF THE STUDY

In the present study, we studied the potential anti-proliferative activity and anti-tumor mechanism of TCS on gastric cancer in vitro and in vivo.

METHODS

In vitro, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was used to detect the proliferation ability of TCS on SGC-7901 cells and AGS cells. Flow cytometry were performed to analyze cell apoptosis, cell cycle, mitochondrial membrane potential and reactive oxygen species expression level. Western blotting was performed to validate the expression of proteins in related pathways. In vivo, a xenograft model was established by injecting SGC-7901 cells into nude mice.

RESULTS

In vitro, TCS inhibited the proliferation of gastric cancer cells. TCS effectively induced apoptosis by PI3K/Akt/mTOR signaling pathway in SGC-7901 cells, and promoted apoptosis via p53-mediated pathway in AGS cells. TCS also exhibited inhibitory activity in blocking the migration of gastric cancer cells. In vivo, TCS significantly inhibited the growth of xenograft tumor.

CONCLUSION

These results indicated that TCS exhibited significant anti-gastric cancer effects in vitro and in vivo.

T-17, a spirostanol saponin, inhibits p53-independent proliferation and p53-dependent migration of gastric cancer cells

The p53 tumor suppressor gene contributes to a series of life processes of cells. Previously, we have shown that T-17, a spirostanol saponin extracted from Tupistra chinensis induces cell cycle arrest, apoptosis and autophagy in gastric cancer cells. The p53 is essential in the cell cycle arrest induced by T-17, however, the effect of p53 on T-17-induced apoptosis and autophagy is still unclear. Here, our study shows that T-17 has no difference in the sensitivity of gastric cancer cells with different p53 status. By transfecting p53 siRNA into AGS cells (p53 wild type cells) or wild-type p53 into KATO-III cells (p53 deficiency cells), T-17 was found to induce apoptosis and autophagy in gastric cancer cells in a p53-independent manner. Pre-treatment with N-acetylcysteine (NAC, a ROS scavenger) demonstrated that reactive oxygen species (ROS) mediated T-17-induced p53-independent apoptosis. Besides, T-17 induces apoptosis and autophagy in gastric cancer cells by decreasing the expression of HMGB1, also in a p53-independent manner. But when we detected the inhibitory effect of T-17 on gastric cancer cell migration, it was found that p53 is essential. These experimental results showed that T-17 induced apoptosis and autophagy in gastric cancer cells in a p53-independent manner, but inhibited the migration of gastric cancer cells in a p53-dependent manner. Our research indicates that T-17 is a potential candidate for gastric cancer and provides support for better utilization of Tupistra chinensis.

A spirostanol saponin isolated from Tupistra chinensis Baker simultaneously induces apoptosis and autophagy by regulating the JNK pathway in human gastric cancer cells

T-17, a bioactive spirostanol saponin extracted from Tupistra chinensis Baker, was previously reported with anti-inflammatory and cytotoxic activities. However, the mechanism underlying of its anti-proliferation activity remains to be elucidated. In this study, we investigated the anti-gastric cancer cell growth activity of T-17 in terms of cell viability, colony formation, cell cycle, induction of apoptosis/autophagy, and JNK pathway. T-17 showed dose-dependent cytotoxicity in SGC-7901 and AGS cell lines, it induced caspase-mediated apoptosis as well as G0/G1 phase arrest and modulation of cyclinE2 and p21 expression. In addition, T-17 promoted the cancer cell autophagy as evidenced with increased expression of Beclin-1 and decreased p62 in western blot and formation of GFP-LC3 puncta. Furthermore, T-17-induced autophagy decreased gastric cancer cell apoptosis as assessed by pharmacological autophagy inhibitors and ATG5 siRNA usage. Importantly, the activation of JNK pathway was simultaneously involved in T-17-induced apoptosis and autophagy. Taken together, the results suggest that T-17 is a promising cytotoxic agent for therapeutic treatment of human gastric adenocarcinoma, which provides a good foundation for further research and development of Tupistra chinensis Baker.

Isolation, diversity, and antimicrobial activity of fungal endophytes from Rohdea chinensis (Baker) N.Tanaka (synonym Tupistra chinensis Baker) of Qinling Mountains, China

Endophytic fungi have been emerged as fruitful resources for producing structurally fascinating and biologically active secondary metabolites. However, endophytic fungi from medicinal plants of Qinling Mountains–the most important natural climatic boundary between the subtropical and warm temperate zones of China with an astonishingly high level of biodiversity–have rarely been explored as potential sources of novel fungal species and active secondary metabolites. In this study, a total of 371 fungal colonies were successfully isolated from 510 tissue segments of the medicinal Tupistra chinensis Baker collected from Qinling Mountains, China. Roots of T. chinensis Baker are used as a folk medicine to ameliorate pharyngitis and treat rheumatic diseases. A total of 100 representative morphotype strains were identified according to ITS rDNA sequence analyses and were grouped into three phyla (Ascomycota, Basidiomycota, Mucoromycota), seven classes (Dothideomycetes, Sordariomycetes, Eurotiomycetes, Microbotryomycetes, Agaricomycetes, Leotiomycetes, Mortierellomycetes), and at least 35 genera. The genera of Collectotrichum (IF, 29.92%), Fusarium (IF, 8.36%), Aspergillus (IF, 8.09%), and Dactylonectria (IF, 5.39%) were most frequently isolated from the tissues of T. chinensis Baker. The Species Richness Index (S, 65) and the Shannon-Wiener Index (H′, 3.7914) indicated that T. chinensis Baker harbored abundant fungal resources. Moreover, five isolates were potential new taxa because of low similarity of ITS sequences ranged from 95.09%∼96.61%. Fifteen out of 100 endophytic fungal ethyl acetate extracts exhibited inhibitory activities against at least one pathogenic bacterium or fungus. Two important lead compounds produced by two stains (F8047 and F8075) with high antimicrobial activities were identified using high performance liquid chromatography (HPLC) and ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry (UPLC–QTOF MS) analyses. In addition, it was noteworthy that the strain F8001, which may be a potential new species, showed antimicrobial activity and should be investigated further. Overall, these results indicated that the endophytic fungi from T. chinensis Baker could be exploited as a novel source of bioactive compounds.

Furostanol saponins from Chinese onion induce G2/M cell-cycle arrest and apoptosis through mitochondria-mediate pathway in HepG2 cells

Phytochemical investigations on the bulbs of Chinese onion led to the isolation of three new furostanol saponins (1, 2, 5) together with seven known furostanol saponins (3, 4, 6-10). Their chemical structures were elucidated on the basis of spectroscopic and chemical methods, including IR, MS, NMR, and GC analyses. The anti-proliferative and anti-inflammatory activities of the isolates were evaluated. Compounds 7-10 showed potential anti-proliferative activities against human cancer cell lines (HepG2, A549, SPC-A-1, MGC80-3, MDA-MB-231, SW620 and CNE-1) with IC₅₀ values below 30 μM. Compounds 4 and 7 could induce G2/M cell-cycle arrest and apoptosis through mitochondria-mediate pathway in HepG2 cells. Compounds 7 and 10 showed strong inhibitory effects against LPS induced NO production in RAW264.7 cells with IC₅₀ values of 2.01 ± 1.40 μM and 2.49 ± 1.54 μM, respectively.

Separation and Bioactive Assay of 25R/S-Spirostanol Saponin Diastereomers from Yucca schidigera Roezl (Mojave) Stems

In order to find a simple, generic, efficient separation method for 25R/S-spirostanol saponin diastereomers, the liquid chromatographic retention behaviors of C₁₂ carbonylation and C₁₂ unsubstituted 25R/S-spirostanol saponin diastereomers on different stationary phases (C₈, C₁₈, C₃₀ columns) and different mobile phases (MeOH-1% CH₃COOH and CH₃CN-1% CH₃COOH) were investigated. A C₃₀ column was firstly found to offer the highest efficiency for the separation of this kind of diastereomers than C₈ and C₁₈ columns. Meanwhile, the analysis results indicated that both CH₃CN-1% CH₃COOH and MeOH-1% CH₃COOH eluate systems were selective for C₁₂ unsubstituted 25R/S-spirostanol saponin diastereomers, while MeOH-1% CH₃COOH possessed better selectivity for C₁₂ carbonylation ones. Using the abovementioned analysis method, six pairs of 25R/S-spirostanol saponin diastereomers 1a–6a and 1b–6b from Yuccaschidigera Roezl (Mojave) were isolated successfully by using HPLC on C₃₀ column for the first time. Among them, three pairs were new ones, named as (25R)-Yucca spirostanoside E₁ (1a), (25S)-Yucca spirostanoside E₁ (1b), (25R)-Yucca spirostanoside E₂ (2a), (25S)-Yucca spirostanoside E₂ (2b), (25R)-Yucca spirostanoside E₃ (3a), (25S)-Yucca spirostanoside E₃ (3b), respectively. Moreover, 3a, 5a, 6a, 3b–6b showed strong inhibitory activities on the growth of SW620 cell lines with the IC₅₀ values of 12.02–69.17 μM.

Anti-inflammatory steroidal glycosides from the berries of Solanum nigrum L. (European black nightshade)

Seven previously undescribed steroidal glycosides, along with three known congeners were isolated from the unripe berries of Solanum nigrum L. (Solanaceae). Their structures were elucidated on basis of 1D and 2D NMR, HR-ESI-MS spectroscopic data and GC analysis after acid hydrolysis. The potential inhibitory effects on nitric oxide (NO) production induced by lipopolysaccharide in RAW 264.7 cell line and the anti-proliferative activities against five cancer cell lines (HL-60, U-937, Jurkat, K562 and HepG2) were evaluated. Seven compounds exhibited inhibition activities on NO production with IC₅₀ values ranging from 11.33 to 49.35 μM. Structure-activity relationships of the isolated compounds were also discussed.

Natural Products Research in China From 2015 to 2016

This review covers the literature published by chemists from China during the 2015-2016 on natural products (NPs), with 1,985 citations referring to 6,944 new compounds isolated from marine or terrestrial microorganisms, plants, and animals. The emphasis is on 730 new compounds with a novel skeleton or/and significant bioactivity, together with their source organism and country of origin.

Apoptosis and pro-death autophagy induced by a spirostanol saponin isolated from Rohdea chinensis (Baker) N. Tanaka (synonym Tupistra chinensis Baker) on HL-60 cells

BACKGROUND

Our previous study has revealed that the spirostanol saponins isolated from the rhizomes of Rohdea chinensis (Baker) N. Tanaka (synonym Tupistra chinensis Baker) (Convallariaceae) (a reputed folk medicine) exhibited potent antiproliferative activity. However, the underlying mechanism of purified saponins remains unclear. More studies are necessary to assess the apoptosis and autophagy activities of the saponins from R. chinensis and clarify their antiproliferative mechanisms.

PURPOSE

The present study certificated the potential antiproliferative activity and mechanism of 5β-spirost-25(27)-en-1β,3β-diol-1-O-α-L-rhamnopyranosyl-(1→2)- β-D-xylopyranosyl-3-O-α-L-rhamnopyranoside (SPD), a spirostanol saponin from R. chinensis, against human acute promyelocytic leukemia cells (HL-60).

METHODS

The antiproliferative activity of SPD in vitro was evaluated by MTT assay compared with cis-dichlorodiammineplatinum (II). The autophagic activity was assessed using MDC staining and western blot, cell apoptosis inspection was detected by Annexin V-FITC/PI double staining and the mitochondrial membrane potential was detected by JC-1 fluorescence dye combined with flow cytometry. The potential mechanisms for protein levels of apoptosis and autophagy were evaluated by western blot.

RESULTS

Treatment of HL-60 cells with SPD resulted in growth inhibition (IC₅₀ value of 2.0 ± 0.2 µM, after 48 h treatment) and induction of apoptosis and autophagy. Results from Annexin V-FITC/PI double-staining assay and mitochondrial membrane potential detection showed that apoptosis was happened after SPD treatment. The regulation of caspase-3, Bax, Bcl-2, PARP following SPD treatment contributed to the induction of mitochondria-dependent apoptosis. Meanwhile, SPD induced autophagy related with Akt/mTOR/p70S6K signaling and activated of AMPK signaling pathway. Furthermore, blocking autophagy with bafilomycin A1 reduced the cytotoxicity of SPD in HL-60 cells.

CONCLUSION

The antiproliferative, apoptosis and pro-death autophagy activities of SPD suggested that spirostanol saponins from R. chinensis would be a potential cytotoxic candidate against acute promyelocytic leukemia.

Antiproliferative and anti-inflammatory furostanol saponins from the rhizomes of Tupistra chinensis

Phytochemical investigations of the rhizome of Tupistra chinensis led to the isolation of ten new furostanol saponins along with fourteen known spirostanols. Their chemical structures were elucidated on the basis of spectroscopic and chemical methods, including IR, NMR, MS, and GC analyses. The antiproliferative effects against FaDu and Detroit 562 cell lines and inhibitory activities on nitric oxide (NO) production induced by lipopolysaccharide (LPS) in a macrophage cell line RAW 264.7 were assayed for all the isolated compounds. Compound 14 exhibited significant antiproliferative effects against FaDu and Detroit 562 cells with IC₅₀ values of 1.1±0.1 and 1.2±0.1μM, respectively. Compounds 1, 2, 6, 13, 16, 19 and 24 exhibited inhibitory effects on NO production with IC₅₀ values ranging from 15.7 to 46.2μM.

Methodology for the Construction of the Bicyclo[4.3.0]nonane Core

The bicyclo[4.3.0]nonane scaffold, commonly known as a hydrindane, is a common structural motif found in many terpenoid structures and one that remains a challenge for synthetic chemists to elaborate with appropriate regio- and stereo-selectivity. Over the course of the study of terpene natural products, the elaboration of the hydrindane structure has seen progress on the utilization of both old and newer methods to achieve the desired outcomes. This review seeks to serve as a general overview of these methods, and detail specific examples.

Antiproliferative and anti-inflammatory polyhydroxylated spirostanol saponins from Tupistra chinensis

Tupistra chinensis is widely distributed in southwestern China and its rhizome is a famous folk medicine for the treatment of carbuncles and pharyngitis. Its chemical identity of potent antiproliferative and anti-inflammatory constituents has been carried out in this study. Twenty-three polyhydroxylated spirostanol saponins, including nine novels, were isolated and identified. The new spirostanol saponins were elucidated as spirost-25(27)-en-1β,2β,3β,4β,5β-pentol-2-O-β-D-xylopyranoside (1), spirost-25(27)- en-1β,2β,3β,4β,5β-pentol-2-O-α-L-arabinopyranoside (2), spirost-25(27)-en- 1β,3α,5β-triol (12), spirost-25(27)-en-1β,3α,4β,5β,6β-pentol (13), spirost-25(27)-en- 1β,2β,3β,5β-tetraol-5-O-β-D-glucopyranoside (16), 5β-spirost-25(27)-en-1β,3β-diol- 3-O-β-D-glucopyranosyl-(1 → 4)-β-D-glucopyranoside (17), (25R)-5β-spirostan- 1β,3β-diol-3-O-β-D-glucopyranosyl-(1 → 6)-β-D-glucopyranoside (18), (25R)-5β- spirostan-1β,3β-diol-3-O-β-D-fructofuranosyl-(2 → 6)-β-D-glucopyranoside (19), 5β-spirost-25(27)-en-3β-ol-3-O-β-D-glucopyranosyl-(1 → 4)-β-D-glucopyranoside (20). The antiproliferative effects against seven human cancer cell lines and inhibitory activities on nitric oxide (NO) production induced by lipopolysaccharide (LPS) in a macrophage cell line RAW 264.7 were assayed for all the isolated compounds. Compounds 17, 19 and 21 exhibited potential antiproliferative activities against all of human cancer cell lines tested. Compounds 21 showed significant inhibition on NO production with IC₅₀ values of 11.5 μM. These results showed that the spirostanol saponins isolated from the dried rhizomes of T. chinensis have potent antiproliferative and anti-inflammatory activities and T. chinensis might be used as anticancer and.anti-inflammatory supplement.