Steroid Glucosides Research Articles

In vitro effect of three tropical plants on adult Haemonchus placei, an haematophagous nematode from cattle

BackgroundVernonia amygdalina (leaf), Garcinia kola (seed), and Leucaena leucocephala (seed) are three well-known tropical plants used in African ethnomedicine to reduce parasitic worm burdens and are potential sources of alternative solution for controlling parasitic helminths infection in grazing livestock. This study investigated extracts from these plants for anthelmintic activity against adult Haemonchus placei, an haematophagous nematode from cattle abomasa. Powdered plant materials were macerated in acetone and the crude acetone extracts evaluated for anthelmintic activity using H. placei adult worm motility assay. Afterwards, fresh sample of V. amygdalina was macerated successively in chloroform and acetone and the extracts evaluated for anthelmintic activity. The chloroform extract was subjected to phytochemical and FT-IR analyses and fractionated by vacuum liquid chromatography. Anthelmintic data were fitted to a nonlinear regression equation (Log [extract or fraction] vs. lethality; variable slope) to produce best-fit sigmoidal curves and LC50 values computed with associated uncertainty.ResultsOf the three tropical plants, only V. amygdalina was active against adult H. placei with best-fit LC50 of 6.51 mg/mL (95% CI: 5.32–7.75). Evaluation of the two extracts obtained by successive maceration showed that chloroform extract (LC50, 2.46 mg/mL, 95% CI: 1.87–3.28) was 11 times as potent as acetone extract (LC50, 27.01 mg/mL, 95% CI: 21.32–48.57) (α < 0.0001). Chromatographic fractionation of the chloroform extract yielded four fractions (FA-FD) with FB (LC50, 2.38 mg/mL, 95% CI: 1.76–3.28) 2.19 times as potent as FC (LC50, 5.21 mg/mL, 95% CI: 4.40–5.79) against H. placei, while FA and FD were inactive. Phytochemical evaluation of the chloroform extract revealed the presence of saponins, steroids, terpenoids, cardiac glycosides, and the absence of tannins, flavonoids, alkaloids, and anthraquinones. FT-IR structural analysis of chloroform extract indicated the presence of key functional groups which are chemical fragments/ structural motifs known to be present in the two major classes of bioactive compounds (sesquiterpene lactones and steroid glucosides) reportedly to be found in V. amygdalina.ConclusionsThe findings showed that chloroform extract of V. amygdalina leaf possessed relatively good anthelmintic activity against adult H. placei. This could be indicative of its potential usefulness as an anthelmintic phytomedicine to control gastrointestinal nematodes infection in cattle.Key highlightsExtracts of three different plant materials (one leaf, two seeds) were tested against adult Haemonchus placei in vitro;Chloroform extract of Vernonia amygdalina was 11 times as potent as acetone extract;Fractionation of the chloroform extract yielded a bioactive fraction responsible for about 90% of the total lethal effect of the chloroform extract.Bioprocessing of V. amygdalina leaf could produce phytomedicines for organic livestock farming.Graphical abstract

Isolation, structural elucidation and molecular docking studies against SARS-CoV-2 main protease of new stigmastane-type steroidal glucosides isolated from the whole plants of Vernonia gratiosa

Phytochemical investigation of the whole plants of Vernonia gratiosa Hance. led in the isolation and identification of two new stigmastane-type steroidal glucosides (1–2), namely vernogratiosides A (1), and B (2). Their chemical structures were fully elucidated based on 1 D/2D NMR spectroscopic, HR-ESI-MS data analyses, and by producing derivatives by chemical reactions. The binding potential of the isolated compounds to replicase protein − main protease of SARS-CoV-2 were examined using the molecular docking simulations. Our results show that the isolated steroidal glucosides (1–2) bind to the substrate‐binding site of SARS-CoV-2 main protease with binding affinities of −7.2 and −7.6 kcal/mol, respectively, as well as binding abilities equivalent to N3 inhibitor that has already been reported (–7.5 kcal/mol).

Phytochemical and Pharmacological Properties of Allium Ursinum

Abstract Allium ursinum L. is a perennial herbaceous plant belonging to the Alliaceae family. Several classes of bioactive compounds have been isolated from A. ursinum so far, among them sulfur and phenolic compounds as quantitatively the most distributed constituents, responsible for pharmaceutical eff ects of the plant. Small amounts of steroidal glucosides, lecitins, fatty acids and several amino acids, as well as the essential oil are also present in A. ursinum. This plant species is characterized by a long history of use in traditional medicine in the prevention and treatment of cardiovascular disease, as digestive stimulant, antimicrobial agent, as a remedy in respiratory problems, insomnia and fainting. Despite its widespread use for medicinal purposes since the ancient time, studies referring to its pharmacological activity are still lacking. In this review, we summarized the current knowledge related to the phytochemical and pharmacological properties of Allium ursinum. This study may be a starting point for future researches in this field, which would fully clarify therapeutic potential of A. ursinum and make it a possible candidate for medicinal product.

Chemical Constituents from the Whole Plant of Cuscuta reflexa

Two new 2H-pyran-2-one glucosides, cuscutarosides A (1) and B (2), and one new steroidal glucoside, 7β-methoxy-β-sitosterol 3-O-β-glucopyranoside (3), together with 12 known compounds (4–15) were isolated from the whole plant of Cuscuta reflexa (Convolvulaceae) collected from Myanmar. The chemical structures of these new compounds were elucidated based on extensive spectroscopic analysis. The antiobesity activity of these isolates was evaluated using porcine pancreatic lipase (PPL), and the antiplatelet aggregation activity was screened using rabbit platelets induced by thrombin, platelet-activating factor (PAF), arachidonate (AA), or collagen. 7β-Methoxy-β-sitosterol 3-O-β-glucopyranoside (3) showed weak PPL inhibitory activity. Cuscutaroside A (1), its acetylated derivative (1a), and scrophenoside B (8) showed weak inhibitory activity against rabbit platelet aggregation induced by collagen. Compound 1a also showed inhibitory activity against rabbit platelet aggregation induced by AA.Graphic

Effects of total C-21 steroidal glucosides from Cynanchum auriculatum on oxidative stress pathway in mice with liver injury

The study aimed to investigate the mechanism of hepatoprotective effect of C-21 steroidal glucosides from Cynanchum auriculatum( Baishouwu) on oxidative stress in mice with liver injury. Mice were randomly divided into normal group,model group,positive control group,Baishouwu high group and Baishouwu low group. The liver injury model was induced by intraperitoneal injection of CCl4 peanut oil solution. All mice were sacrificed to collect blood and liver specimens. The activities of serum levels of ALT and AST were detected. The content of MDA and the activity of SOD in liver homogenate were examined by colorimetry method. Tissues were stained with hematoxylin-eosin for histological examination. The hepatic protein expressions of NF-κB p65,p-IκBα,i NOS and COX-2 were detected by Western blot. The mRNA expressions of TNF-α and IL-6 were determined by RT-PCR. It was found that treatment with C-21 steroidal glucosides from Baishouwu successfully attenuated liver injury induced by CCl4,as shown by decreased levels of serum biochemical indicators( AST,ALT)( P<0. 01). Administration of total C-21 steroidal glucosides enhanced the activity of SOD( P<0. 01) and decreased the content of MDA( P<0. 01) in liver homogenate. Microscopic features suggested that treatment with C-21 steroidal glucosides from Baishouwu was effective in inhibiting CCl4-induced hepatocyte edema and degeneration. Further studies showed that NF-κB p65 overexpression induced by CCl4 was decreased by C-21 steroidal glucosides,leading to the markedly down-regulated protein expression levels of p-IκBα,i NOS and COX-2,as well as the depression of TNF-α and IL-6 mRNA expressions. In conclusion,total C-21 steroidal glucosides from Baishouwu exhibited potent effect on oxidative stress pathway in mice with liver injury induced by CCl4,with enhanced activity of SOD,decreased content of MDA,and down-regulated levels of NF-κB p65,p-IκBα,i NOS and COX-2.

Phytochemical and Pharmacological Properties of Allium Ursinum

Abstract Allium ursinum L. is a perennial herbaceous plant belonging to the Alliaceae family. Several classes of bioactive compounds have been isolated from A. ursinum so far, among them sulfur and phenolic compounds as quantitatively the most distributed constituents, responsible for pharmaceutical effects of the plant. Small amounts of steroidal glucosides, lecitins, fatty acids and several amino acids, as well as the essential oil are also present in A. ursinum. Th is plant species is characterized by a long history of use in traditional medicine in the prevention and treatment of cardiovascular disease, as digestive stimulant, antimicrobial agent, as a remedy in respiratory problems, insomnia and fainting. Despite its widespread use for medicinal purposes since the ancient time, studies referring to its pharmacological activity are still lacking. In this review, we summarized the current knowledge related to the phytochemical and pharmacological properties of Allium ursinum. Th is study may be a starting point for future researches in this field, which would fully clarify therapeutic potential of A. ursinum and make it a possible candidate for medicinal product.

Significance of M2 macrophage in tubulointerstitial disease secondary to primary Sjogren's disease

Objective: M2 Macrophages could improve tubulointerstitial disease in animal models. HIF-1αpromotes macrophage polarization and is involved in tubular injury. The study aims to observe the clinicopathologic significance of M2 macrophage and HIF-1α in tubulointerstitial injury secondary to primary Sjogren's disease.Methods: Renal tissue samples from patients with tubulointerstitial disease secondary to primary Sjogren's disease (SS, n = 10), chronic tubulointerstitial nephritis secondary to drug (CIN, n = 8) were included in this study. The expression of CD163, CD68 and HIF-1α were examined by immunohistochemistry or immunofluorescence.Results: (1) Renal involvement was the first manifestation in seven of ten (7/10) patients with pSS, including proteinuria, renal dysfunction, renal tubular acidosis and multiple renal stone; and two patient had intractable hypokalemia. (2) There were numerous CD163- positive cells and CD68- positive cells infiltration in tubulointerstitial injury of pSS, especially in patients with hypokalemia. CD163 positive cells and HIF-1αwere mainly expressed in acute tubulointerstitial injury of pSS, which positively correlated to N-acetyl-β-D-glucosaminidase and β2-microglobulin. (3) Compared with CIN, patients with pSS had higher serum globulin level, erythrocyte sedimentation rate (ESR) and lower urinary osmotic pressure. (4) During follow-up of one year, six patients with pSS and acute tubular injury acquired improved renal function on therapy of steroid and total glucosides of peony. The remaining four patients with pSS had stable renal function.Conclusion: M2 macrophages are involved in acute tubular injury in patients with primary Sjogren's disease. Early intervention can improve renal function of tubulointerstitial injury secondary to primary Sjogren's disease.

Potential cancer chemopreventive and anticancer constituents from the fruits of Ficus hispida L.f. (Moraceae)

Ethnopharmacological relevanceFicus hispida L.f. (Moraceae) has been used as alternative for traditional medicine in the treatment of various ailments including cancer-cure. The aim of this study was to evaluate the cancer chemopreventive and anticancer activities of crude extracts of F. hispida, with the objective to screen the inhibition of Epstein–Barr virus early antigen, and cytotoxic active components, and provide foundation for potential applications of this promising medical plant. Materials and methodsCompounds were isolated from the MeOH extract of F. hispida fruits, and their structure elucidation was performed on the basis of extensive spectroscopic analysis. The isolated compounds were evaluated for their inhibitory activities against the Epstein–Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol 13-acetate (TPA) in Raji cells, and cytotoxic activities against human cancer cell lines (HL60, A549, SKBR3, KB, Hela, HT29, and HepG2) and a normal cell (LO2) using MTT method. For the compound with potent cytotoxic activity, its apoptosis inducing activity was evaluated by the observation of ROS generation level expression, and membrane phospholipid exposure and DNA fragmentation in flow cytometry. The mechanisms of the apoptosis induction were analyzed by Western blotting. ResultsNineteen compounds, 1–19, including two new isoflavones, 3′-formyl-5,7-dihydroxy-4′-methoxyisoflavone (2) and 5,7-dihydroxy-4′-methoxy-3′- (3-methyl-2-hydroxybuten-3-yl)isoflavone (3), were isolated from the MeOH extract of F. hispida fruits. Five compounds, isowigtheone hydrate (1), 2, 3, 9, and 19, showed potent inhibitory effects on EBV-EA induction with IC50 values in the range of 271–340 molar ratio 32 pmol−1 TPA. In addition, five phenolic compounds, 1–3, 10, and 13, exhibited cytotoxic activity against two or more cell lines (IC50 2.5–95.8μM), as well as compounds 1 and 3 were also displayed high selectivity for LO2/HepG2 (SI 23.5 and 11.8, respectively), while the compound 1-induced ROS generation leads to activated caspases-3, −8, and −9 apoptotic process in HL60 cells. ConclusionThis study has established that the MeOH extract of F. hispida fruits contains isoflavones, coumarins, caffeoylquinic acids, along with other compounds including phenolics and steroid glucoside as active principles, and has demonstrated that the chemical constituents of F. hispida may be valuable as potential chemopreventive and anticancer agents.

Novel saponins from Nigella arvensis var. involucrata

Four new oleanane-type triterpene glycosides namely 3-O-[β-d-glucopyranosyl-(1→2)-β-d-glucopyranosyl-(1→2)-α-l-arabinopyranosyl] oleanolic acid, 3-O-[β-d-glucopyranosyl-(1→2)-β-d-glucopyranosyl-(1→2)-α-l-arabinopyranosyl]-28-O-[α-l-rhamnopyranosyl-(1→4)-β-d-glucopyranosyl-(1→6)-β-d-glucopyranosyl] oleanolic acid, 3-O-[β-d-quinovopyranosyl-(1→3)-α-l-rhamnopyranosyl-(1→2)-α-l-arabinopyranosyl]-28-O-[β-d-glucopyranosyl] oleanolic acid, 3-O-[β-d-quinovopyranosyl-(1→3)-α-l-rhamnopyranosyl-(1→2)-α-l-arabinopyranosyl]-28-O-[α-l-rhamnopyranosyl(1→4)-β-d-glucopyranosyl-(1→6)-β-d-glucopyranosyl] oleanolic acid, were isolated from methanol extract of the roots of Nigella arvensis var. involucrata along with five known oleanane-type triterpene glycosides and a steroid glucoside. Structures of the new compounds were established as by using 1D and 2D NMR techniques and mass spectrometry.

Bioactive steroids and sorbicillinoids isolated from the endophytic fungus Trichoderma sp. Xy24

A new steroid glucoside (1), along with nine known steroids (2–10) and four known sorbicillinoids (11–14), were isolated from the endophytic fungus Trichoderma sp. Xy24. Their structures were elucidated on the basis of spectroscopic data analyses and by comparison with reported data. Compounds 3, 5–7, 9, 10, and 13 exhibited significant inhibitory effects on HIV-1 virus with IC50 values ranging 1.9–9.3 μM; compounds 10, 13, and 14 showed potent inhibitory activity on LPS-induced NO production in BV2 microglia cells with inhibitory rates of 108.2, 100, and 75.1% at 10 μM, respectively. In addition, compound 10 displayed moderate cytotoxicity against BCG823 and HePG2 cell lines with IC50 values of 11.1 and 17.7 μM, respectively.

Triterpenoids and Steroid from the Leaves of Callistemon citrinus (Curtis.)

Three triterpenes a one steroidal glucoside were isolated from the methanolic crude extract and its carbon tetrachloride soluble fraction of the leaves of Callistemon citrinus (Curtis.). The structure of the isolated compounds were established as erythrodiol (1), betulinic acid (2), ?-sitosterol-3-O-?-D-glucoside (3) and taraxerol (4) by high field NMR analyses. This is the first report of the occurrence of these compounds in C. citrinus growing in Bangladesh.Dhaka Univ. J. Pharm. Sci. 15(1): 1-5, 2016 (June)

Studies on the Antioxidant and Antiproliferative Potentials ofCirsium arvensesubsp.vestitum

The antioxidant (DPPH, superoxide anion radical scavenging and FRAP) and antiproliferative activities against Vero cells (african green monkey kidney), C6 cells (rat brain tumor cells) and HeLa cells (human uterus carcinoma) of Cirsium arvense (CA) of all parts [root (Kinghorn et al. 2004), stem (CAS), flower (CAF) and leaves] and isolated compounds were investigated in vitro. CAR was shown to have the highest antiproliferative activity against HeLa and C6 cell lines as compared to other parts. A flavon glucoside (linarin), a steroid glucoside (daucosterin), a steroid (stigmasterol) and a new benzymidazole molecule (E−6-(3-(5,6-dimethoxy-1H-benzo[d] imidazol-2-yl)allyloxy)−5-(hydroxymethyl)-tetrahydro-2H-pyran-2,3,4-triol) were isolated from the CAR. The structures of these molecules were determined by the 13C (carbon) and 1H (proton)- Nuclear Magnetic Resonance (NMR), Fourier Transform Infrared Spectroscopy (FT-IR), and Gas Chromatography-Mass Spectrometry (GC-MS) techniques. CAR for C6 cell line, CAS for HeLa and Vero cell line were observed the highest antiproliferative activity. In addition, CAR showed the stronger DPPH activity than α-tocopherol and BHT at high concentrations. The FRAP and superoxide anion radical scavenging activities of CAR (Fr-7) were found to be higher than BHT. Practical Applications Cirsium species are considered as agricultural weed among villagers in Turkey and are used as alternative medicinal plant for years. Studies have shown that these species are rich with regard to bioactive seconder metabolites. There is no phytochemical/bioactivity study about this plant until now. Our findings showed that the extracts of this plant possessed potent antioxidant activities. Four compounds, one of which is a new one to literature, were isolated and characterized. Finally, Cirsium arvense, being considered as an invader plant in agricultural fields, can be evaluated as a good source of antioxidant products.

Steroidal Glucosides from the Rhizomes of Tacca Chantrieri and Their Inhibitory Activities of NO Production in BV2 Cells

Two new steroidal glucosides, chantriolides D and E (1 and 2), along with four known compounds, chantriolide A (3), chantriolide B (4), chantriolide C (5), and (25S)-spirost-5-en-3-ol 3-O-α-L-rhamnopyranosyl-(1-->2)-O-[α-L-rhamnopyranosyl-(1-->3)]-β-D-glucopyranoside (6) were isolated from the rhizomes of Tacca chantrieri. Their structures were determined by 1D and 2D NMR spectroscopic and HR-ESI-MS data, as well as by comparison with reported data. Compounds 1 and 2 were found to show strong inhibitory NO effect in BV2 cells, with IC₅₀ values of 12.45 and 59.03 µM, respectively.

English

Five compounds were reported for the first time in the tribe Malouetieae from the leaves and stems of Pachypodium lamerei viz., fatty acid methyl ester (stearic acid methyl ester 1), a mixture of two steroidal aglycones (β-sitosterol 2 and stigmasterol 3), a pentacyclic triterpene (ursolic acid 4) and a steroidal glucoside (β-sitosterol-3-O-β-D-glucopyranoside 5). The structure elucidation was based on comparison of their physical, chemical, chromatographic properties, spectral data with literature as well as direct comparison with authentic compounds. The petroleum ether fraction and the total ethanolic extract of (leaves and stems) exhibited minimum inhibitory concentrations (MICs) against Pseudomonas aeruginosa (1.06 and 2.52 μg/ml), respectively. These results are comparable to that obtained by amikacin (MIC, 2.38 μg/ml). Moreover, the petroleum ether fraction displayed the lowest MIC (16.45 μg/ml) against Candida albicans. This result is greatly promising since the standard drug (ketoconazole) exhibited MIC (185.87 μg/ml). This is the first time to estimate both antibacterial and antifungal activities of any of Pachypodium species. Key words: Pachypodium lamerei, Apocynaceae, phytochemical, antimicrobial, antibacterial, antifungal.

Triterpene glycosides and other polar constituents of shea (Vitellaria paradoxa) kernels and their bioactivities

The MeOH extract of defatted shea (Vitellaria paradoxa; Sapotaceae) kernels was investigated for its constituents, and fifteen oleanane-type triterpene acids and glycosides, two steroid glucosides, two pentane-2,4-diol glucosides, seven phenolic compounds, and three sugars, were isolated. The structures of five triterpene glycosides were elucidated on the basis of spectroscopic and chemical methods. Upon evaluation of the bioactivity of the isolated compounds, it was found that some or most of the compounds have potent or moderate inhibitory activities against the following: melanogenesis in B16 melanoma cells induced by α-melanocyte-stimulating hormone (α-MSH); generation of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, against Epstein–Barr virus early antigen (EBV-EA) activation induced by 12-O-teradecanoylphorbol 13-acetate (TPA) in Raji cells; t TPA-induced inflammation in mice, and proliferation of one or more of HL-60, A549, AZ521, and SK-BR-3 human cancer cell lines, respectively. Western blot analysis established that paradoxoside E inhibits melanogenesis by regulation of expression of microphthalmia-associated transcription factor (MITF), tyrosinase, and tyrosinase-related protein-1 (TRP-1) and TRP-2. In addition, tieghemelin A was demonstrated to exhibit cytotoxic activity against A549 cells (IC50 13.5μM) mainly due to induction of apoptosis by flow cytometry. The extract of defatted shea kernels and its constituents may be, therefore, valuable as potential antioxidant, anti-inflammatory, skin-whitening, chemopreventive, and anticancer agents.

Studies on chemical constituents of Ophiopogon japonicus

Two new and six known steroidal glucosides were isolated from the tuber of Ophiopogon japonicus. The new steroidal glucosides were established as (20R,25R)-26-O-β-d-glucopyranosyl-3β,26-dihydroxycholest-5-en-16,22-dioxo-3-O-α-l-rhamnopyranosyl-(1 → 2)-β-d-glucopyranoside (1) and 26-O-β-d-glucopyranosyl-(25R)-furost-5-en-3β,14α,17α,22α,26-pentaol-3-O-α-l-rhamnopyranosyl-(1 → 2)-β-d-glucopyranoside (3) on the basis of spectroscopic data as well as chemical evidence.

A lupane triterpenoid and other constituents of Salvia eremophila

Phytochemical investigation of the aerial parts of Salvia eremophila led to the isolation of a lupane triterpenoid, 3β, 20-dihydroxylupane-28-oic acid (1), together with eight other compounds, comprising three diterpene, two triterpene, two flavonoids and a steroidal glucoside. Their structures were elucidated by interpretation of their one-dimensional and two-dimensional NMR spectra and completed by the analysis of the HRESIMS data. Compounds 1, 2–4 and 8 were evaluated for their cytotoxicities against five human tumour cell lines. Compounds 1 and 3 hold a good potential for use in future studies due to their anti-cancer properties.

New Antifungal Xanthones from the Seeds of Rhus coriaria L.

Phytochemical investigations of the ethanolic extract of the seeds of Rhus coriaria L. (Anacardiaceae) led to the identification of four new xanthones, characterized as 2,3-dihydroxy-7-methyl xanthone (1), 2,3,6-trihydroxy-7-hydroxymethylene xanthone-1-carboxylic acid (2), 2-methoxy-4-hydroxy-7-methyl-3-O-beta-D-glucopyranosyl xanthone-1,8-dicarboxylic acid (4), and 2-hydroxy-7-hydroxymethylene xanthone-1,8-dicarboxylic acid 3-O-beta-D-glucopyranosyl-(2'-->3")-3"-O-stigmast-5-ene (5), along with the known steroidal glucoside beta-sitosterol-beta-D-glucoside (3). The structures of the isolated compounds have been identified on the basis of spectral data analysis and chemical reactions. All xanthones were active against Aspergillus flavus.

Vernonia amygdalina, an ethnoveterinary and ethnomedical used green vegetable with multiple bio-activities.

Today, researches are focusing on the discovery of new therapeutic substances of natural origin with possible low or no toxicity to human, animal and environment, based on ethnomedical and ethnoveterinary practices.Vernonia amygdalina is a shrub that has been commonly known as bitter leaf due the bitter taste of the leaves. It is widely used as a daily green vegetable or herb to treat malaria and diabetes. The potential of V. amygdalina was first noted when scientists observed chimpanzees use the pith of this shrub for self-deparasitization. Since that discovery, subsequent researches had unveiled more and more bioactivities possessed by different extracts of this plant such as antidiabetic, antibacterial, antimalaria, antifungal, antioxidant, liver protection and cytotoxic effects which are beneficial to health. Compounds including steroid glucosides, sesquiterpene lactones and flavonoids which contributed to its bitter taste and bioactivites have also been isolated from this plant. Toxicology studies documented on this plant shows that V. amygdalina has low or no toxicity thereby supporting the safe use of this plant for the benefits of health. Keywords: Vernonia amygdalina, bioactivities, antidiabetic, antioxidant, liver protection.

Isolation and characterization of the antibreast carcinoma cell growth components of Vernonia amygdalina extracts

Vernonia amygdalina (VA) is widely used for medicinal and food purposes in tropical Africa. Many health benefits (antioxidant, antimicrobial, anticancer activities and more) of VA extracts have been reported. The mechanisms of actions have also been described. We have previously reported that VA extracts elicited growth inhibitory activities in human estrogen receptor-positive (ER(+)) cells (MCF-7 cells) and ductal carcinoma cells (BT-549) in vitro. The active components in the organic solvent (chloroform)-extracted VA have been previously determined. However, the active components in the ethanolic extracts of VA have not been previously studied. Hence, the objectives of this study are to isolate and characterize the active components of the ethanolic extracts of VA using liquid-liquid extraction, thin layer chromatography and column techniques. Fractionation of the ethanolic extracts of VA yielded three fractions named A1, A2 and A3, and A2 retained the DNA synthesis-inhibitory activity of the extracts. Subsequent fractionation of A2 yielded fraction A2B whose activity was 16 and three times more potent than the ethanolic fraction and fraction A2, respectively. The treatment of cells with 100 μg/mL of either the ethanolic VA extracts, fraction A2 or fraction A2B resulted in a 23% (P < 0.01), 86% (P < 0.0001) and 97% (P < 0.0001) inhibition of DNA synthesis compared with vehicle-treated controls, respectively. Further purification of A2B by high-speed countercurrent chromatography and confirmed by spectroscopic analysis revealed that the major active components of A2B (65% by weight) were steroid glucosides.