Two new nortriterpenoid saponins from Salicornia bigelovii Torr. and their cytotoxic activity

Optimization of Microwave-Assisted Extraction Process of Total Flavonoids from Salicornia bigelovii Torr. and Its Hepatoprotective Effect on Alcoholic Liver Injury Mice

The objective of this study was to determine the optimal extraction conditions for total flavonoids from S. bigelovii using microwave-assisted extraction and to analyze the protective effect of total flavonoids from S. bigelovii on alcoholic liver injury in mice. The optimization of the process conditions for the microwave-assisted extraction of total flavonoids from S. bigelovii was performed using response surface methodology, and an alcohol-induced acute liver injury model in mice was used to investigate the effects of different doses of total flavonoids (100 mg/kg, 200 mg/kg, and 400 mg/kg) on the levels and activities of serum alanine aminotransferase kits (ALT), glutamic oxaloacetic transaminase kits (AST), superoxide dismutase kits (SOD), glutathione peroxidase kits (GSH-Px), and malondialdehyde (MDA). We performed hematoxylin-eosin (H&E) staining analysis on pathological sections of mouse liver tissue, and qRT-PCR technology was used to detect the expression levels of the inflammatory factors IL-1 β, IL-6, and TNF-α. The results revealed that the optimal extraction process conditions for total flavonoids in S. bigelovii were a material-to-liquid ratio of 1:30 (g/mL), an ethanol concentration of 60%, an extraction temperature of 50 °C, an ultrasound power of 250 W, and a yield of 5.71 ± 0.28 mg/g. Previous studies have demonstrated that the flavonoids of S. bigelovii can significantly inhibit the levels of ALT and AST in the serum (p < 0.001), reduce MDA levels (p < 0.001), increase the activity of the antioxidant enzymes SOD and GSH-Px (p < 0.001), and inhibit the IL-1 β, IL-6, and TNF-α gene expression levels (p < 0.001) of inflammatory factors. The total flavonoids of S. bigelovii exert a protective effect against alcoholic liver injury by reducing the levels of inflammation, oxidative stress, and lipid peroxidation caused by alcohol. The results of this study lay the foundation for the high-value utilization of S. bigelovii and provide new resources for the development of liver-protective drugs.

Salt-Tolerant Plants, Halophytes, as Renewable Natural Resources for Cancer Prevention and Treatment: Roles of Phenolics and Flavonoids in Immunomodulation and Suppression of Oxidative Stress towards Cancer Management

Halophytes and xerophytes, plants with adequate tolerance to high salinity with strong ability to survive in drought ecosystem, have been recognized for their nutritional and medicinal values owing to their comparatively higher productions of secondary metabolites, primarily the phenolics, and the flavonoids, as compared to the normal vegetation in other climatic regions. Given the consistent increases in desertification around the world, which are associated with increasing salinity, high temperature, and water scarcity, the survival of halophytes due to their secondary metabolic contents has prioritized these plant species, which have now become increasingly important for environmental protection, land reclamation, and food and animal-feed security, with their primary utility in traditional societies as sources of drugs. On the medicinal herbs front, because the fight against cancer is still ongoing, there is an urgent need for development of more efficient, safe, and novel chemotherapeutic agents, than those currently available. The current review describes these plants and their secondary-metabolite-based chemical products as promising candidates for developing newer cancer therapeutics. It further discusses the prophylactic roles of these plants, and their constituents in prevention and management of cancers, through an exploration of their phytochemical and pharmacological properties, with a view on immunomodulation. The important roles of various phenolics and structurally diverse flavonoids as major constituents of the halophytes in suppressing oxidative stress, immunomodulation, and anti-cancer effects are the subject matter of this review and these aspects are outlined in details.

Salicornia bigelovii, S. brachiata and S. herbacea: Their Nutritional Characteristics and an Evaluation of Their Potential as Salt Substitutes

Excessive sodium (salt) intake in our diet is a main contributor to hypertension and a major risk factor for cardiovascular illnesses. As a result, research has made great efforts to develop salt alternatives, and Salicornia spp. offers a very high potential in the food industry for its promising functional characteristics. This review focuses on the nutritional profile, health effects and commercial potential of three specific species of the Salicornia genus: S. bigelovii, S. brachiata and S. herbacea. It also addresses the methods that are used to produce them as salt substitutes. Owing to the antinutritional and anti-inflammatory effects of its bioactive compounds, Salicornia spp. can serve as an organic biological preservative in foods with better consumer appeal when compared with chemical preservatives that are common in the food industry. Overall, the commercial use of these underutilized species will help to improve food security.

Chemical Structure and Biological Activities of Secondary Metabolites from Salicornia europaea L

Salicornia europaea L. is a halophyte that grows in salt marshes and muddy seashores, which is widely used both as traditional medicine and as an edible vegetable. This salt-tolerant plant is a source of diverse secondary metabolites with several therapeutic properties, including antioxidant, antidiabetic, cytotoxic, anti-inflammatory, and anti-obesity effects. Therefore, this review summarizes the chemical structure and biological activities of secondary metabolites isolated from Salicornia europaea L.

Preparative mass-spectrometry profiling of minor concentrated metabolites in Salicornia gaudichaudiana Moq by high-speed countercurrent chromatography and off-line electrospray mass-spectrometry injection

Salicornia species have just been introduced to the European market as a vegetable named 'samphire', 'green asparagus', or 'sea asparagus'. Due to its increasing attention, and associated value, minor compounds of Salicornia gaudichaudiana Moq were investigated. The use of countercurrent chromatography and mass spectrometry enabled the search for known, as well as potentially novel natural products. Their identification was achieved based on molecular weights and mass-spectrometric fragmentation data. Low detection limits enabled the visualization of all compounds with their identification in almost real time close to the preparative countercurrent chromatography experiment. A list of known natural products from Salicornia genus guided the identification process of compounds occurring in Salicornia gaudichaudiana Moq by tandem mass spectrometry fragment comparison. The natural product classes were divided into four groups: chlorogenic acid derivatives; flavonoid derivatives; pentacyclic triterpenoid saponins; and other compounds.

Evaluation of Cytotoxic Effect of Different Extracts of Seidlitzia rosmarinus on HeLa and HepG2 Cell Lines

Background:

Seidlitzia rosmarinus which is commonly called “Oshnan” or “Eshnan” in Persian belongs to Chenopodiaceae family. Conventionally, it is believed that this plant is toxic. This study was aimed to evaluate the cytotoxic effect of S. rosmarinus against HeLa and HepG₂ cell lines.

Materials and Methods:

S. rosmarinus was collected from the desert near Yazd, Iran. Hexane, chloroform, chloroform/methanol (9:1), and butanol extracts of aerial parts of S. rosmarinus were prepared. Doxorubicin and dimethyl sulfoxide 10% were used as positive and negative control, respectively. The cytotoxic activity was measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.

Results:

All extracts significantly and concentration dependently reduced viability of HeLa and HepG2 cells. Hexane, chloroform, and butanol extracts at doses of 200, 500, 750, and 1000 μg/ml significantly reduced HeLa cell viability (P < 0.05). Chloroform/methanol extract at doses of 100–500 μg/ml significantly reduced HeLa cell viability (P < 0.05). Hexane, chloroform, and butanol extracts at doses of 500, 750, and 1000 μg/ml significantly reduced HepG2 cell viability (P < 0.05). Chloroform/methanol extract at doses of 200, 300, 400, and 500 μg/ml significantly reduced HepG cell viability (P < 0.05). The most cytotoxic extract was chloroform/methanol extract in both cell lines. Furthermore, in the both cell lines, the second potent extract was chloroform extract.

Conclusions:

It can be concluded from the findings of this study that S. rosmarinus is a good candidate for further study to find new cytotoxic agents. Phytochemical investigation on chloroform/methanol extract and their structures is recommended.

Induction of apoptosis by Bigelovii A through inhibition of NF‑κB activity

Bigelovii A is a 30-nortriterpenoid glycoside, isolated from Salicornia bigelovii Torr. Until now, the effect of Bigelovii A on breast cancer treatment was unknown. The present research indicated that Bigelovii A significantly inhibited the proliferation of human breast cancer cells (MCF-7, MDA-MB-231 and MDA-MB-468) in a concentration-dependent manner. It was particularly effective in MCF7 cells, with an IC₅₀ value of 4.10±1.19 µM. The anti-proliferative effect of Bigelovii A was ascribed to the induction of apoptosis, which was characterized by chromatin condensation, externalization of phosphatidylserine on the plasma membrane, hypodiploid DNA, activation of caspases and poly (ADP-ribose) polymerase cleavage. Furthermore, Bigelovii A reduced B-cell lymphoma 2 (Bcl-2) and B-cell lymphoma-extra large (Bcl-xl) expression and caused disruption of mitochondrial membrane potential, which are indicative features of mitochondria-dependent apoptotic signals. It was also identified that Bigelovii A downregulated the constitutive activation of nuclear factor (NF)-κB, as indicated by the electrophoretic mobility gel shift assay and immunocytochemistry. Furthermore, Bigelovii A suppressed constitutive IκBα phosphorylation via inhibition of IκB kinase activity. In addition to the effects on Bcl-2 and Bcl-xl, Bigelovii A also downregulated the expression of the NF-κB-regulated gene products, Cyclin D1 and cyclooxygenase-2. This led to the induction of apoptosis and arrest of cells at the G1 phase of the cell cycle.

Computational Modeling of the Staphylococcal Enterotoxins and Their Interaction with Natural Antitoxin Compounds

Staphylococcus aureus is an opportunistic bacterium that produces various types of toxins, resulting in serious food poisoning. Staphylococcal enterotoxins (SEs) are heat-stable and resistant to hydrolysis by digestive enzymes, representing a potential hazard for consumers worldwide. In the present study, we used amino-acid sequences encoding SEA and SEB-like to identify their respective template structure and build the three-dimensional (3-D) models using homology modeling method. Two natural compounds, Betulin and 28-Norolean-12-en-3-one, were selected for docking study on the basis of the criteria that they satisfied the Lipinski’s Rule-of-Five. A total of 14 and 13 amino-acid residues were present in the best binding site predicted in the SEA and SEB-like, respectively, using the Computer Atlas of Surface Topology of Proteins (CASTp). Among these residues, the docking study with natural compounds Betulin and 28-Norolean-12-en-3-one revealed that GLN43 and GLY227 in the binding site of the SEA, each formed a hydrogen-bond interaction with 28-Norolean-12-en-3-one; while GLY227 residue established a hydrogen bond with Betulin. In the case of SEB-like, the docking study demonstrated that ASN87 and TYR88 residues in its binding site formed hydrogen bonds with Betulin; whereas HIS59 in the binding site formed a hydrogen-bond interaction with 28-Norolean-12-en-3-one. Our results demonstrate that the toxic effects of these two SEs can be effectively treated with antitoxins like Betulin and 28-Norolean-12-en-3-one, which could provide an effective drug therapy for this pathogen.

Six New Triterpene Derivatives from Aralia chinensis Var. dasyphylloides

Aralia chinensis var. dasyphylloides is widely distributed in China and used as a traditional herbal medicine for the treatment of digestive and immune system diseases. The present study aimed to search for novel oleanolic-type triterpenoids in low-polarity fractions. Six new triterpene derivatives (1-6), together with two known compounds were isolated from the barks of A. chinensis var. dasyphylloides. Their structures were elucidated by 1D- and 2D-NMR spectroscopic analysis and chemical methods. They were identified as 3-oxo-oleana-11,13(18)-dien-28,30-dioic acid (1), 30-hydroxy-3-oxo-oleana-11,13(18)-dien-28-oic acid (2), 3β-hydroxy-oleana-11,13(18)-dien-28-oic acid-28-O-β-d-glucopyranoside (3), 3β,30-dihydroxy-oleana-11,13(18)-dien-28-oic acid-28-O-β-d-glucopyranoside (4), 3β-hydroxy-oleana-11,13(18)-dien-28-oic acid-3-O-β-d-xylopyranosyl-(1 → 2)-β-d-glucopyranoside (5), 3β,29-dihydroxy-oleana-9(11),12-dien-28-oic acid-28-O-β-d-glucopyranoside (6), namely, araliachinolic acids I and II and araliachinosides I-IV. The cytotoxicity of the isolated compounds was tested against HepG2, A549, SGC7901, and MCF7 cell lines, but no apparent activity was observed at a concentration of 50 μM.

Bigelovii A Protects against Lipopolysaccharide-Induced Acute Lung Injury by Blocking NF-κB and CCAAT/Enhancer-Binding Protein δ Pathways

Optimal methods are applied to acute lung injury (ALI) and the acute respiratory distress syndrome (ARDS), but the mortality rate is still high. Accordingly, further studies dedicated to identify novel therapeutic approaches to ALI are urgently needed. Bigelovii A is a new natural product and may exhibit anti-inflammatory activity. Therefore, we sought to investigate its effect on lipopolysaccharide- (LPS-) induced ALI and the underlying mechanisms. We found that LPS-induced ALI was significantly alleviated by Bigelovii A treatment, characterized by reduction of proinflammatory mediator production, neutrophil infiltration, and lung permeability. Furthermore, Bigelovii A also downregulated LPS-stimulated inflammatory mediator expressions in vitro. Moreover, both NF-κB and CCAAT/enhancer-binding protein δ (C/EBPδ) activation were obviously attenuated by Bigelovii A treatment. Additionally, phosphorylation of both p38 MAPK and ERK1/2 (upstream signals of C/EBPδ activation) in response to LPS challenge was also inhibited by Bigelovii A. Therefore, Bigelovii A could attenuate LPS-induced inflammation by suppression of NF-κB, inflammatory mediators, and p38 MAPK/ERK1/2-C/EBPδ, inflammatory mediators signaling pathways, which provide a novel theoretical basis for the possible application of Bigelovii A in clinic.

Triterpenoids from the Herbs of Salicornia bigelovii

A new nortriterpene saponin, 3-O-β-d-glucuronopyranosyl-30-norolean-12,20(29)-dien-23- oxo-28-oic acid, namely bigelovii D (11), was isolated from the hydroalcoholic extract of herbs of Salicornia bigelovii along with 10 known saponins (1-10). Their chemical structures were identified on the basis of spectroscopic analyses including two-dimensional NMR and a comparison with literature data. Some of these compounds showed potent antifungal activities in vitro. Compounds 3, 4, 5, 6, 7, 10 and 11 demonstrated potent inhibitory activities against Colletotrichum gloeosporioides and compound 11 displayed broad-spectrum inhibitory activity against Alternaria alternata, A. solani, Botrytis cinerea, C. gloeosporioides, Fusarium graminearum, F. verticilloides, Thanatephorus cucumeris and Sclerotinia sclerotiorum, with EC50 values ranging from 13.6 to 36.3 μg/mL.

Isolation, identification and cytotoxicity of a new noroleanane-type triterpene saponin from Salicornia bigelovii Torr

Salicornia bigelovii Torr. has been consumed not only as a popular kind of vegetable, but also as a medicinal plant to treat hypertension, cephalalgia, scurvy and cancer. The present study was designed to investigate its chemical components and cytotoxic activity. A new noroleanane-type triterpene saponin, bigelovii C (1), was separated and purified from Salicornia bigelovii Torr., along with four known triterpene saponins 2-5. The structure of bigelovii C was elucidated as 3-O-(6-O-butyl ester)-β-D-glucuropyranosyl-23-aldehyde-30-norolean-12, 20 (29)-dien-28-oic acid-28-O-β-D-glucopyranoside, according to various spectroscopic analysis and chemical characteristics. Besides Compounds 3 and 5, bigelovii C had potent cytotoxicity against three human cancer cell lines, MCF7 (breast cancer), Lovo (colon cancer) and LN229 (glioblastoma), especially MCF7. Bigelovii C inhibited the growth of MCF7 cells in dose- and time-dependent manners. Flow cytometry analysis revealed that the percentage of apoptotic cells significantly increased upon bigelovii C treatment. Rh123 staining assay indicated that bigelovii C reduced the mitochondrial membrane potential. The mechanism of cell death by bigelovii C may be attributed to the downregulation of Bcl-2 and upregulation of Bax, cleaved caspase-9, caspase-7 and PARP. These results suggested that bigelovii C may impart health benefits when consumed and should be regarded as a potential chemopreventative agent for cancer.

Solvent system selectivities in countercurrent chromatography using Salicornia gaudichaudiana metabolites as practical example with off-line electrospray mass-spectrometry injection profiling

For the development of an efficient two-stage isolation process for high-speed countercurrent chromatography (HSCCC) with focus on principal metabolites from the ethyl acetate extract of the halophyte plant Salicornia gaudichaudiana, separation selectivities of two different biphasic solvent systems with similar polarities were evaluated using the elution and extrusion approach. Efficiency in isolation of target compounds is determined by the solvent system selectivity and their chronological use in multiple separation steps. The system n-hexane-ethyl acetate-methanol-water (0.5:6:0.5:6, v/v/v/v) resulted in a comprehensive separation of polyphenolic glycosides. The system n-hexane-n-butanol-water (1:1:2, v/v/v) was less universal but was highly efficient in the fractionation of positional isomers such as di-substituted cinnamic acid quinic acid derivatives. Multiple metabolite detection performed on recovered HSCCC tube fractions was done with rapid mass-spectrometry profiling by sequential off-line injections to electrospray mass-spectrometry (ESI-MS/MS). Selective ion traces of metabolites delivered reconstituted preparative HSCCC runs. Molecular weight distribution of target compounds in single HSCCC tube fractions and MS/MS fragment data were available. Chromatographic areas with strong co-elution effects and fractions of pure recoverable compounds were visualized. In total 11 metabolites have been identified and monitored. Result of this approach was a fast isolation protocol for S. gaudichaudiana metabolites using two solvent systems in a strategic sequence. The process could easily be scaled-up to larger lab-scale or industrial recovery.

Triterpenoids

This review covers the isolation and structure determination of triterpenoids reported during 2012 including squalene derivatives, lanostanes, holostanes, cycloartanes, cucurbitanes, dammaranes, euphanes, tirucallanes, tetranortriterpenoids, quassinoids, lupanes, oleananes, friedelanes, ursanes, hopanes, serratanes, isomalabaricanes and saponins; 348 references are cited.

Triterpenoid glycosides from the leaves of Meliosma henryi

Seven triterpenoid glycosides, named meliosmosides A-G, were isolated from the leaves of Meliosma henryi Diels (Sabiaceae). Their structures were elucidated by different spectroscopic methods including 1D and 2D NMR experiments as well as HRESIMS analysis. Isolated compounds were evaluated for their cytotoxic activity against KB cell line.

The apoptotic effect of D Rhamnose β-hederin, a novel oleanane-type triterpenoid saponin on breast cancer cells

There is growing interest in development of natural products as anti-cancer and chemopreventive agents. Many triterpenoids have been proved as potential agents for chemoprevention and therapy of breast cancer. Ginsenosides from ginseng, which mostly belong to dammarane-type triterpenoids, have gained great attention for their anti-breast cancer activity with diverse mechanisms. However, studies of other kinds of triterpenoid saponins on breast cancer are limited. Previously, we purified and identified a novel oleanane-type triterpene saponin named D Rhamnose β-hederin (DRβ-H) from Clematis ganpiniana, a Chinese traditional anti-tumor herb. In the present study, DRβ-H showed strong inhibitory activity on the growth of various breast cancer cells and induced apoptosis in these cells. DRβ-H inhibited PI3K/AKT and activated ERK signaling pathway. PI3K inhibitor LY294002 synergistically enhanced DRβ-H-induced apoptosis whereas MEK inhibitor U0126 reduced the apoptosis rate. Moreover, DRβ-H regulated the ratio of pro-apoptotic and anti-apoptotic Bcl-2 family proteins. Furthermore, DRβ-H induced depolarization of mitochondrial membrane potential which released Apaf-1 and Cytochrome C from the inter membrane space into the cytosol, where they promoted caspase-9 and caspase-3 activation. This is the first report on the pro-apoptotic effects of DRβ-H, a novel oleanane-type triterpenoid saponin, on breast cancer cells and its comprehensive apoptosis pathways. It implied that oleanane-type triterpenoid saponin DRβ-H could be a promising candidate for chemotherapy of breast cancer.

A PKS I gene-based screening approach for the discovery of a new polyketide from Penicillium citrinum Salicorn 46

Salicorn 46, an endophytic fungus isolated from Salicornia herbacea Torr., was identified as Penicillium citrinum based on its internal transcribed spacer and ribosomal large-subunit DNA sequences using a type I polyketide synthase (PKS I) gene screening approach. A new polyketide, penicitriketo (1), and seven known compounds, including ergone (2), (3β,5α,8α,22E)-5,8-epidioxyergosta-6,9,22-trien-3-ol (3), (3β,5α,8α,22E)-5,8-epidioxyergosta-6,22-dien-3-ol (4), stigmasta-7,22-diene-3β,5α,6α-triol (5), 3β,5α-dihydroxy-(22E,24R)-ergosta-7,22-dien-6β-yl oleate (6), N b-acetyltryptamine (7), and 2-(1-oxo-2-hydroxyethyl) furan (8), were isolated from the culture of Salicorn 46, and their chemical structures were elucidated by spectroscopic analysis. Antioxidant experiments revealed that compound 1 possessed moderate DPPH radical scavenging activity with an IC50 value of 85.33 ± 1.61 μM. Antimicrobial assays revealed that compound 2 exhibited broad-spectrum antimicrobial activity against Candida albicans, Clostridium perfringens, Mycobacterium smegmatis, and Mycobacterium phlei with minimal inhibitory concentration (MIC) values of 25.5, 25.5, 18.5, and 51.0 μM, respectively. Compound 3 displayed potent antimicrobial activities against C. perfringens and Micrococcus tetragenus with a MIC value of 23.5 μM. Compounds 5 and 6 showed high levels of selectivity toward Bacillus subtilis and M. phlei with MIC values of 22.5 and 14.4 μM, respectively. The results of this study highlight the use of PCR-based techniques for the screening of new polyketides from endophytic fungi containing PKS I genes.

Two new noroleanane-type triterpene saponins from the methanol extract of Salicornia herbacea

Two new noroleanane-type triterpene saponins, Salbige A (1) and Salbige B (2), have been isolated from the aerial parts of Salicornia herbacea together with five other known compounds, including echinocystic acid (3), gypsogenin (4), pheophorbide a (5), (13(2)S)-hydroxy-pheophorbide a (6) and (13(2)S)-hydro-pheophorbide-lactone a (7). The chemical structures of these compounds were elucidated by extensive spectroscopic analysis and on the basis of their chemical reactivity. This work represents the first recorded example of the isolation of these compounds from S. herbacea. Compounds 1 and 2 exhibited potent antiproliferative activities and high levels of selectivity towards A549 cancer cells, with IC50 values of 52.35 and 79.39 μM, respectively, whereas compound 5 showed high levels of inhibitory activity against A549 and HepG2 cancer cells with IC50 values of 6.15 and 17.56 μM, respectively. None of these compounds exhibited antioxidant activities except for compound 7, which showed weak antioxidant activity.

Bigelovii A induces apoptosis of HL‑60 human acute promyelocytic leukaemia cells

In the present study, the antitumor effects of the nor‑Oleanane type triterpene saponin, Bigelovii A, isolated from Salicornia bigelovii Torr, were examined. Bigelovii A was demonstrated to inhibit HL‑60 human acute promyelocytic leukaemia cell growth with an IC50 value of 2.15 µg/ml. In addition, Bigelovii A promoted apoptosis in HL‑60 cells, as shown by apoptotic morphological changes and the hypodiploid cell assay. Apoptotic induction by Bigelovii A was associated with the downregulation of Bcl‑2, the upregulation of Bax and the activation of caspase‑3, as demonstrated by RT‑PCR and western blot analysis. In addition, a lactate dehydrogenase release test indicated that Bigelovii A may exhibit cytotoxic activity by the induction of cell membrane impairment. This study is the first to identify that Bigelovii A exhibits potential antitumor activity and induces marked apoptosis and membrane permeabilisation in HL‑60 cells. Bigelovii A may be a novel candidate for future cancer therapy.