[Physiological response to drought stress and drought resistance of six Helleborus orientlis cultivars]. / å ­ä¸ªä¸œæ–¹é“ç­·å­å“ç§å¯¹å¹²æ—±èƒè¿«çš„ç”Ÿç†å“åº”åŠæŠ—æ—±æ€§è¯„ä»·.

We examined the responses of physiological and leaf anatomic structural characteristics of six Helleborus orientalis cultivars to different degrees of drought stress. A membership function was used to evaluate drought resis-tance and identify physiological and leaf anatomical indicators that exhibited a stronger correlation with drought tolerance. The results showed that leaf thickness, leaf area per unit mass and soluble protein levels of the six cultivars significantly decreased with the increases of drought stress. Net photosynthetic rate, stomatal conductance, and transpiration rate of leaves increased first and then decreased, while the intercellular CO2 concentration decreased. The relative electrical conductivity, MDA, and H2O2 contents of leaves were increased. Soluble saccharide and proline contents, and antioxidant enzyme activities were first elevated and then decreased. With the increases of drought stress, the ratio of palisade tissue thickness to sponge tissue thickness and stomatal density increased. Key indicators and relativities in evaluating drought resistance of those cultivars were proline, soluble sugars, and the ratio of palisade tissue thickness to sponge tissue thickness. H. orientalis 'Anemone Red' and H. orientalis 'Ane-mone Red spotted' had better drought resistance, which could be the excellent parental materials for the cultivation of new drought-resistant cultivars in the future.

[Chemical constituents of Helleborus thibetanus].

The chemical constituents of Helleborus thibetanus were isolated and purified by silica gel column chromatography, Sephadex LH-20 gel column chromatography, and semi-preparative RP-HPLC, and the structures of all compounds were identified by modern spectrographic technology(MS, NMR). The MTT method was used to measure the cytotoxicity of compounds 1-8. Twelve compounds were isolated from the roots and rhizomes of H. thibetanus and were identified as(25R)-22ß,25-expoxy-26-[(O-ß-D-glucopyranosyl)oxy]-1ß,3ß-dihydroxyfurosta-5-en(1), ß-sitosterol myristate(2), ß-sitosterol lactate(3), ß-sitosterol 3-O-ß-D-glucopyrannoside(4), 4,6,8-trihydroxy-3,4-dihydronaphthalen-1(2H)-one(5), 1,3,5-trimethoxybenzene(6), 7,8-dimethylbenzo pteridine-2,4(1H,3H)-dione(7), 1H-indole-3-carboxylic acid(8), p-hydroxy cinnamic acid(9), lauric acid(10), n-butyl α-L-arabinofuranoside(11) and methyl-α-D-fructofuranoside(12), respectively. Among them, compound 1 is a new compound and named thibetanoside L; compounds 2, 5-8, 11 are first isolated from the family Ranunculaceae; compound 12 is isolated from the genus Helleborus for the first time. The results of MTT assay showed that the IC_(50) values of compounds 1-8 against HepG2 and HCT116 cells were greater than 100 µmol·L~(-1).

Chemical constituents isolated from the aerial parts of Helleborus cyclophyllus (A. Braun) Boiss. (Ranunculaceae), evaluation of their antioxidant and anti-inflammatory activity in vitro and virtual screening of molecular properties and bioactivity score.

Chemical investigation of ethyl acetate extract from the aerial parts of Helleborus cyclophyllus (A.Braun) Boiss. led to the isolation of ten natural products, and their structures were identified to be: 2-deoxy-D-ribono-1,4-lactone (1), 2-O-feruloyl-L-malate (2), three flavonoids: quercetin 3-O-ß-D-galactopyranoside (3), quercetin 3-O-6''-(3-hydroxy-3-methyl-gloutaryl)-ß-D-glucopyranoside (4) and quercetin 3-O-(2‴-caffeoylsophoroside) (5), 6-O-caffeoyl-1-O-p-coumaroyl-ß-D-glucopyranoside (6), two ecdysteroids: 20-hydroxyecdysone (7) and polypodine B (8) and two bufadienolides: deglucohellebrin (9) and hellebrin (10), on the basis of MS and NMR spectra. This is the first report on the occurrence of compounds (2)-(6) in the genus Helleborus. The chemotaxonomic significance of these compounds was summarised. Bioactivity score, molecular and pharmacokinetic properties of the isolated compounds were calculated by online computer software program Molinspiration. Compounds showed promising bioactivity scores for drug targets. Moreover, some of the isolated phenolic compounds were tested for their antioxidant and antiinflammatory activities. Tested compounds presented antioxidant ability correlated to the presence of the phenolic hydroxyl groups.

Bufadienolides and ecdysteroids from the whole plants of Helleborus niger and their cytotoxicity.

A new bufadienolide (1), two new bufadienolide glycosides (2 and 3), a new ecdysteroid (4), and four known compounds (5-8), were isolated from the whole plants of Helleborus niger L. (Ranunculaceae). The structures of the new compounds (1-4) were determined by spectroscopic analysis, including 2D NMR spectral data, and hydrolytic studies. Compounds 1-6 showed cytotoxicity against HL-60 human leukemia cells, A549 human lung adenocarcinoma cells, and SBC-3 human small-cell lung cancer cells, with IC50 values ranging from 0.0055 to 1.9 µM. HL-60 cells treated with either 3 or 4 showed apoptosis characteristics, such as nuclear chromatin condensation, accumulation of sub-G1 cells, and activation of caspase-3/7.

[Chemical-toxicological diagnosis of hellebore (veratrum) poisoning]. / Khimiko-toksikologicheskaya diagnostika otravlenii chemeritsei.

The problem of laboratory diagnosis of acute and fatal poisoning by hellebore, which is possible when used in traditional medicine, the erroneous use of hellebore preparations orally or use of various types of this plant for food, remains relevant. Currently, in the practice of chemical-toxicological laboratories and the bureau of forensic medical examination there is no single approach to the laboratory diagnosis of such poisoning. The diagnosis is most often based on anamnesis. In this regard, the development and validation of a legally significant methodology for the determination of hellebore alkaloids in various biological objects seems relevant. The physicochemical and toxic properties of alkaloids of various types of hellebore are characterized. It was shown that for the identification of hellebore alkaloids, it is advisable to use HPLC-MS/MS as the most sensitive and specific instrumental method corresponding to the characteristics of hellebore alkaloids (high molecular weight, high thermal lability, high polarity).

Bufadienolide glycosides and bufadienolides from the whole plants of Helleborus lividus, and their cytotoxic activity.

Cytotoxicity-guided fractionation of the MeOH extract of Helleborus lividus Aiton ex Curtis (Ranunculaceae) resulted in the isolation of five undescribed bufadienolide glycosides and two undescribed bufadienolides, along with three known compounds. Their structures were determined by detailed spectroscopic analysis and hydrolysis studies. The isolated compounds showed cytotoxicity against HL-60 human leukemia cells and A549 human lung adenocarcinoma cells, with IC50 values ranging from 2.20 ± 0.01 nM to 0.77 ± 0.01 µM. The undescribed compound 3ß-[(O-ß-d-glucopyranosyl-(1 â†’ 4)-α-l-rhamnopyranosyl)oxy]-14ß,16ß-dihydroxy-5ß-bufa-20,22-dienolide induced apoptosis in HL-60 cells via a mitochondria-dependent apoptotic pathway. The average IC50 values of bufadienolide monorhamnosides for HL-60 and A549 cells were 10-20 times lower than those for Na+/K+ ATPase, implying that they induce tumor cell death via a mechanism of action other than Na+/K+ ATPase inhibition.

Stability of protoanemonin in plant extracts from Helleborus niger L. and Pulsatilla vulgaris Mill.

The concentration levels and stability of protoanemonin, a characteristic constituent of Ranunculaceae species with antimicrobial and fungicidal properties, were studied for the first time in plant extracts prepared from Helleborus niger L. and Pulsatilla vulgaris Mill. using fermentative production processes. Protoanemonin levels quantified by HPLC-DAD analysis were 0.0345 and 0.0662 mg/g in two freshly prepared Helleborus (whole, flowering plant) extracts and 0.3875 mg/g and 0.4193 mg/g in Pulsatilla (flowers) extracts. Protoanemonin proved to be rather instable in aqueous-fermented extracts stored at 15 °C in the dark, and its concentration decreased rapidly over 12 months of storage independently of the plant species. The decrease was most pronounced when initial concentrations were high (decrease by about 70%). In contrast, low protoanemonin levels remained stable in solution for more than 12 months. Anemonin, the dimer of protoanemonin, was detected in increasing concentrations only in Pulsatilla samples, but its concentration only accounted for less than 50% of the theoretically expected amount. With respect to fermented extracts, both physical processes such as self-polymerization and adsorption/binding to other extract constituents as well as biodegradation were concluded to be responsible for protoanemonin decline. As opposed to plant extracts, both protoanemonin and anemonin levels decreased in 0.22 µm-filtered samples stored in vials. This may be explained by a reduced release from plant material in combination with physicochemically induced degradation. Reduction was most pronounced upon light exposure and elevated temperatures, clearly indicating that photochemical degradation is involved. Contents of protoanemonin in a set of extract batches were 0.0896 ± 0.0125 mg/g and 0.0618 ± 0.0180 mg/g in Helleborus and Pulsatilla extracts, and anemonin levels were 0.0230 ± 0.0076 mg/g and 0.0482 ± 0.0282 mg/g, respectively. Due to its antibiotic effects, but also its reactivity, protoanemonin is a therapeutically and toxicologically relevant constituent, and its concentration should therefore be carefully monitored.

Antiseizure potential of the ancient Greek medicinal plant Helleborus odorus subsp. cyclophyllus and identification of its main active principles.

ETHNOPHARMACOLOGICAL RELEVANCE: Ethnopharmacological data and ancient texts support the use of black hellebore (Helleborus odorus subsp. cyclophyllus, Ranunculaceae) for the management and treatment of epilepsy in ancient Greece. AIM OF THE STUDY: A pharmacological investigation of the root methanolic extract (RME) was conducted using the zebrafish epilepsy model to isolate and identify the compounds responsible for a potential antiseizure activity and to provide evidence of its historical use. In addition, a comprehensive metabolite profiling of this studied species was proposed. MATERIALS AND METHODS: The roots were extracted by solvents of increasing polarity and root decoction (RDE) was also prepared. The extracts were evaluated for antiseizure activity using a larval zebrafish epilepsy model with pentylenetetrazole (PTZ)-induced seizures. The RME exhibited the highest antiseizure activity and was therefore selected for bioactivity-guided fractionation. Isolated compounds were fully characterized by NMR and high-resolution tandem mass spectrometry (HRMS/MS). The UHPLC-HRMS/MS analyses of the RME and RDE were used for dereplication and metabolite profiling. RESULTS: The RME showed 80% inhibition of PTZ-induced locomotor activity (300 µg/ml). This extract was fractionated and resulted in the isolation of a new glucopyranosyl-deoxyribonolactone (1) and a new furostanol saponin derivative (2), as well as of 20-hydroxyecdysone (3), hellebrin (4), a spirostanol glycoside derivative (5) and deglucohellebrin (6). The antiseizure activity of RME was found to be mainly due to the new furostanol saponin (2) and hellebrin (4), which reduced 45% and 60% of PTZ-induced seizures (135 µM, respectively). Besides, the aglycone of hellebrin, hellebrigenin (S34), was also active (45% at 7 µM). To further characterize the chemical composition of both RME and RDE, 30 compounds (A7-33, A35-37) were annotated based on UHPLC-HRMS/MS metabolite profiling. This revealed the presence of additional bufadienolides, furostanols, and evidenced alkaloids. CONCLUSIONS: This study is the first to identify the molecular basis of the ethnopharmacological use of black hellebore for the treatment of epilepsy. This was achieved using a microscale zebrafish epilepsy model to rapidly quantify in vivo antiseizure activity. The UHPLC-HRMS/MS profiling revealed the chemical diversity of the extracts and the presence of numerous bufadienolides, furostanols and ecdysteroids, also present in the decoction.

Novel Steroidal Glycosides from the Whole Plants of Helleborus foetidus.

Phytochemical analysis of the whole Helleborus foetidus plants identified 28 steroidal glycosides (1-28), including 20 novel spirostanol glycosides (1-20) and a novel furostanol glycoside (21). The structures of the newly identified compounds were elucidated by two-dimensional NMR spectroscopy and hydrolytic cleavage. Compounds 12, 13, and 15 were determined to be spirostanol trisdesmosides bearing sugar moieties at the C-1, -21, and -24 hydroxy groups of the aglycone unit. The isolated compounds were subsequently evaluated for cytotoxic activity against HL-60 human promyelocytic leukemia cells and A549 human lung carcinoma cells. In particular, 7 showed cytotoxic activity against the HL-60 and A549 cells, with IC50 values of 5.9 and 6.6 µM, respectively, whereas 19 was selectively cytotoxic to A549 cells with an IC50 value of 5.5 µM.

Bufadienolides from the whole plants of Helleborus foetidus and their cytotoxicity.

Two undescribed bufadienolide glucosides and four undescribed bufadienolides were isolated from the whole plants of Helleborus foetidus (Ranunculaceae). Their structures were determined by extensive spectroscopic analysis and the results of hydrolytic cleavage. The isolated compounds exhibited cytotoxic activities against HL-60 and A549 cells with IC50 values ranging from 0.019 to 3.0 µM. The isolated compounds also showed the Na+/K+ ATPase inhibitory activity. The undescribed compound 16ß-formyloxy-10,14-dihydroxy-5ß-[(ß-d-glucopyranosyl)oxy]-19-norbufa-3,20,22-trienolide induced apoptosis in HL-60 cells through a mitochondria-dependent apoptotic pathway.

Three new spirostanol glycosides from Helleborus thibetanus.

An ongoing chemical investigation on n-BuOH extract of roots and rhizomes of Helleborus thibetanus afforded three new spirostanol glycosides (1-3). Their structures were elucidated by extensive analysis of 1 D, 2 D NMR spectra, together with IR and MS methods and acid hydrolysis. This is the first report of the isolation of spirostanol glycoside with xylose at C-24 of the aglycone in Helleborus.

New cytotoxic bufadienolides from the roots and rhizomes of Helleborus thibetanus Franch.

Three new bufadienolides 14ß, 16ß-dihydroxy-3ß-[ß-D-glucopyranosyl-(1→6)-(ß-D-glucopyranosyl)oxy]-5α-bufa-20, 22-dienolide (1), 14ß-hydroxy-3ß-[ß-D-glucopyranosyl-(1→4)-(ß-D-glucopyranosyl)oxy]-5α-bufa-20, 22-dienolide (2) and hellebrigenin-3-O-ß-D-glucosyl-(1→4)-ß-D-glucoside (3), together with eight known bufadienolides (4-11) were isolated from the roots and rhizomes of Helleborus thibetanus. Their structures were elucidated by extensive spectroscopic methods and acid hydrolysis. Compounds 1-7 were evaluated for their cytotoxic activity against HCT116, A549 and HepG2 tumor cell lines. Compound 1 exhibited moderate cytotoxicity against HepG2 cells with IC50 value of 15.1 ± 1.72 µM. Compounds 5 and 6 exhibited moderate cytotoxicity against HCT116 cells with IC50 values of 15.12 ± 0.58 µM and 13.17 ± 2.34 µM, respectively.

Studies on the constituents of Helleborus purpurascens: use of derivatives from calix[6]arene, homooxacalix[3]arene and homoazacalix[3]arene as extractant agents for amino acids from the aqueous extract.

The task of this work was to investigate the extraction capacity of various calixarenes for free and esterified amino acids from aqueous acid phases. Furthermore, this method was applied to aqueous extracts of Helleborus purpurascens. Generally, it is known that calixarenes can be used as extractants for ammonium compounds due to π-cation and lone pair cation interactions. As first, tert-Butyl-calix[6]arene and derivatives thereof were used. They had already proven their worth in previous investigations. In addition, tert-Butyl-hexahomooxa-calix[3]arene was used also, which can also enter into lone pair cation interactions. In addition to these well-known calixarenes, new calixarenes were produced and tested. Based on the tert-Butyl-hexahomooxa-calix[3]arene, a phosphor(III)bridged derivative was prepared, combining the three aromatic hydroxyl groups to a phosphite. As a seldom-described class of calixarenes, tert-Butyl-hexahomoaza-calix[3]arene derivatives were used. The nitrogen analogues of tert-Butyl-hexahomooxa-calix[3]arene could be produced as N-benzyl derivatives. The structure of the esterified carboxymethylated derivative of N,N',N″-Tribenzyl-tert-Butyl-hexahomoaza-calix[3]arene could be verified by X-ray structure analysis. It crystallized as a partial cone. The extraction capacity of the described calixarenes was investigated for amino acids from aqueous acidic solutions into an organic phase. For the testing were chosen asparagine, aspartic acid, tyrosine, tryptophane, phenylalanine and pipecolinic acid and their methyl esters. The amino acids and their methyl esters were dissolved in water at different pH values. The calixarenes were dissolved in dichloromethane (DCM) or chloroform. After this preparation, the aqueous acidic amino acid solutions were mixed with the solutions and shaken intensively. In addition, blank values were determined by extracting the aqueous stock solutions of the amino acids and their methyl esters with pure solvents. To determine the extraction rate, the phases were separated and each analysed using GC-FID, partially GC-MS(EI). The evaluation is performed in two ways. On the one hand the depletion in the aqueous phase and on the other hand the content in the organic phase was determined.

Steroidal constituents from Helleborus thibetanus and their cytotoxicities.

Thibetanosides E-H (1-4), four new steroidal constituents including three rare sulfonates (2-4), were isolated from the roots and rhizomes of Helleborus thibetanus, together with nine known steroidal compounds (5-13). Their structures were elucidated by detailed spectroscopic analysis, including 1D and 2D NMR techniques and chemical evidence. In this study, compounds 2-13 were evaluated for their cytotoxic activities against HCT116, A549 and HepG2 tumor cell lines in vitro. Among them, compound 8 (thibetanoside C) showed cytotoxicities against A549 cells(IC50 39.6 ± 1.9 µmol·L-1) and HepG2 cells(IC50 41.5 ± 1.1 µmol·L-1), respectively. Compound 9 (23S, 24S)-24-[(O-ß-D-fucopyranosyl)oxy]-3ß, 23-dihydroxy-spirosta-5, 25(27)-diene-1ß-ylO-(4-O-acetyl- α-L-rhamnopyranosyl)-(1→2)-O-[ß-D-xylopyranosyl-(1→3)]-α-L-arabinopyranoside) showed cytotoxicity against HCT116 cells(IC50 33.6 ± 2.1 µmol·L-1).

Cardiac Glycoside Compound Isolated from Helleborus thibetanus Franch Displays Potent Toxicity against HeLa Cervical Carcinoma Cells through ROS-Independent Autophagy.

The current study aimed to examine the anticancer activity of HTF-1, a cardiac glycoside (CG) isolated from Helleborus thibetanus Franch, using a cell-based model and to discover the underlying mechanisms with specific focus on autophagy. We found that HTF-1 was able to potently decrease the viability of several cancer cell lines especially for HeLa cervical carcinoma cells. It was discovered that HTF-1 dose dependently induced overproduction of ROS in HeLa cells, and the cell viability can be rescued when adding ROS scavenger N-acetyl-l-cysteine (NAC). More, we found that HTF-1 induced ROS-independent autophagy in concentration- and time-dependent manners in HeLa cells. This can be collectively verified by LC3-II and p62 abundance and also eGFP-LC3 puncta assay, bafilomycin clamp experiment, and acidotropic dye fluorescent labeling experiment. Additionally, TEM examination showed more autophagic vacuoles for HTF-1-treated HeLa cells. In HeLa cells, pretreatment with wortmannin (an inhibitor of the initial stages of autophagy to block autophagosome formation, thus, it should weaken the autophagy induction effect of HTF-1) decreased the autophagic flux and partially antagonized cell death induced by HTF-1, indicating that autophagy induced by HTF-1 played a cancer-suppressing role. Furthermore, coadministration of BAF (as a distal inhibitor of autophagy) with HTF-1 demonstrated a synergistic anticancer effect against HeLa cells. We believe that our work will enrich the understanding of CGs and especially anticarcinoma activity, also, pave the way for natural-product-based anticancer drug development.

Within-plant heterogeneity in fecundity and herbivory induced by localized DNA hypomethylation in the perennial herb Helleborus foetidus.

PREMISE: Phenotypic heterogeneity of reiterated, homologous structures produced by individual plants has ecological consequences for plants and their animal consumers. This paper examines experimentally the epigenetic mosaicism hypothesis, which postulates that within-plant variation in traits of reiterated structures may partly arise from different parts of the same genetic individual differing in patterns or extent of genomic DNA methylation. METHODS: Leaves of paired ramets borne by field-growing Helleborus foetidus plants were infiltrated periodically over the entire flowering period with either a water solution of the demethylating agent zebularine or just water as the control. The effects of the zebularine treatment were assessed by quantifying genome-wide DNA cytosine methylation in leaves and monitoring inflorescence growth and flower production, number of ovules per flower, pollination success, fruit set, seed set, seed size, and distribution of sap-feeding insects. RESULTS: Genomic DNA from leaves in zebularine-treated ramets was significantly less methylated than DNA from leaves in control ones. Inflorescences in treated ramets grew smaller and produced fewer flowers, with fewer ovules and lower follicle and seed set, but did not differ from inflorescences in untreated ramets in pollination success or seed size. The zebularine treatment influenced the within-plant distribution of sap-feeding insects. CONCLUSIONS: Experimental manipulation of genomic DNA methylation level in leaves of wild-growing H. foetidus plants induced considerable within-plant heterogeneity in phenotypic (inflorescences, flowers, fecundity) and ecologically relevant traits (herbivore distribution), which supports the hypothesis that epigenetic mosaicism may partly account for within-plant variation.

Preclinical evaluation of safety and potential of black hellebore extracts for cancer treatment.

BACKGROUND: The therapeutic use of Helleborus niger L. is manifold due to its specific phytochemical composition. Two compound groups, the ranunculin derivates including protoanemonin and the steroidal saponins, are also associated with toxicity (genotoxicity, disintegration of membrane structures). Therefore, in vitro investigations were performed on safety aspects of a Helleborus niger aqueous fermented extract (HNE). In addition its therapeutic potential against various cancer cell lines was assessed to gain insight into the respective mechanisms of action. METHODS: To evaluate the safe use of HNE, Ames and hemolytic tests were carried out. Two angiogenesis assays in 2D and 3D design were conducted to assess the anti-angiogenetic potential, for which human umbilical vein endothelial cells (HUVEC) were chosen. A panel of tumor cell lines was used in 2D and 3D proliferation assays as well in the migration- and invasion-assay. All investigations were performed with HNE compared to reference substances. The 2D proliferation assay was additionally performed with isolated compounds of HNE (characteristic steroidal saponins). RESULTS: HNE did not exhibit any genotoxic potential. Concentrations up to 10 µl/ml were classified as non-hemolytic. HNE exerted anti-angiogenetic effects in HUVEC and anti-proliferative effects in five cancer cell lines, whereas hellebosaponin A and D as well macranthosid I did not show comparable effects neither singly nor in combination. Due to the inherent instability of protoanemonin in isolated form, parallel investigations with protoanemonin could not be performed. HNE (600-1000 µg/ml) inhibited the migration of certain cancer cells by > 80% such as Caki-2, DLD-1 and SK-N-SH. CONCLUSION: HNE exhibit neither genotoxic nor hemolytic potential. The present investigations verify the anti-angiogenetic effects on HUVEC, the anti-proliferative effects and migration-inhibiting properties on tumor cells. The lower effect of the relevant steroidal saponins compared to the whole extract underlines the fact that the latter is more effective than a blend of isolated pharmacologically active components.

A cardiac glycoside HTF-1 isolated from Helleborus thibetanus Franch displays potent in vitro anti-cancer activity via caspase-9, MAPK and PI3K-Akt-mTOR pathways.

Experiments have been undertaken and for the first time, we have identified that a new cardiac glycoside (CG) isolated from Helleborus thibetanus Franch. a plant endemic to China, bears potent anti-cancer activity. We have named it as HTF-1. By using in vitro cell models, we have found that HTF-1 induces apoptosis against several types of cancer cells in a concentration- and time-dependent manner. It is able to inhibit cancer cell in proliferation, migration and invasion. HTF-1 causes S cell cycle arrest. Further-on, we have identified that HTF-1 triggers caspase-9 dependent apoptosis pathway and double strand DNA breaks (DSBs). Additionally, HTF-1 activates JNK, but suppresses ERK and PI3K-Akt-mTOR pathways. Collectively, the above-mentioned mechanisms contribute to the anti-cancer activity of HTF-1. It is rare to discover novel anti-cancer CG during the past couple of decades. We believe that our work will enrich the understanding of CGs; also, pave the way for natural product-based anti-cancer drug development.