Pyrroloquinolones B-F: Five unusual alkaloids from Vernonia glabra (Steetz) Vatke (Asteraceae).

Five unusual alkaloids featuring a pyrrolo[1,2-a]quinolone skeleton (pyrroloquinolones B-F, 1-5) were isolated from the ethanol extract of the whole plant of Vernonia glabra (Steetz) Vatke, along with sixteen known compounds. Their structures were established by means of spectroscopic (1D and 2D NMR, UV, IR, and ECD) and high resolution mass spectrometric techniques as well as by comparison of their spectroscopic data with those reported in the literature. The ethanol extract and some isolated compounds were assessed for their antibacterial activity against four bacterial strains. The extract was significantly active against Staphylococcus aureus ATCC1026 and S. epidermidis ATCC35984 (MIC = 64 µg/mL). All the tested compounds showed moderate activity against S. epidermidis (16 ≤ MIC ≤ 64 µg/mL). Furthermore, this is the first report on tricyclic pyrrolo[1,2-a]quinolone alkaloids from a plant source. A biosynthetic pathway for the formation of these compounds is also proposed.

Stigmastane-type steroid saponins from the leaves of Vernonia amygdalina and their α-glucosidase and xanthine oxidase inhibitory activities.

Two new vernonioside K (1) and vernonioside L (2) and four known Δ7,9(11) stigmastane-type steroidal saponins-vernonioside B2 (3), vernoniacum B (4), vernonioside B1 (5), and vernoamyoside A (6)-were isolated from the leaves of Vernonia amygdalina. Their structures were determined by comprehensive spectroscopic analysis with one-dimensional nuclear magnetic resonance, two-dimensional nuclear magnetic resonance, and high-resolution mass spectrometry. All isolated compounds (1-6) were evaluated to determine their inhibitory effects on α-glucosidase and xanthine oxidase. Among them, two new compounds 1 and 2 showed significant inhibition of α-glucosidase with IC50 values of 78.56 ± 7.28 and 14.74 ± 1.57 (µM), respectively, comparable with acarbose as a positive control (127.53 ± 1.73 µM); none of these compounds inhibited xanthine oxidase activity. Compounds 1 and 2 are promising candidates for the development of antidiabetic agents from natural sources.

Therapeutic Benefit of Vernonia amygdalina in the Treatment of Diabetes and Its Associated Complications in Preclinical Studies.

Diabetes mellitus (DM), a complex heterogeneous metabolic disorder characterized by a defect in the function of insulin, is on the rapid rise globally. Sustained hyperglycemia which is a major sign of DM is linked to the generation of reactive oxygen species which promotes adverse complications of the disorder. Traditional herbal treatment of DM is a common practice in Africa and other tropical parts of the world. Vernonia amygdalina (VA), one of the highly researched species in the Asteraceae family, has proven to possess potent antidiabetic properties. Several phytochemicals identified in multiple extracts from VA are purported to be responsible for the antidiabetic potential of the plant. In this review, we discuss the therapeutic potential of VA in diabetes and its associated complications. We appraise the current evidence and further suggest potential areas that could be effectively exploited in future VA research on diabetes.

Insight on Vernonia Plant for its Pharmacological Properties: A Review.

Vernonia is a woody shrub of the family Asteraceae. Over 1500 species are distributed in tropical and subtropical regions of Africa and Asia. There are more than 54 species known to possess similar morphological features with the characteristic bitter taste. The pharmacological properties of different parts like seeds, leaves, and roots are well documented in folk medicine. They are rich in biologically active constituents such as alkaloids, phenolics, flavonoids, terpenoids, steroid tannins, and carotenoids having broad therapeutic activities like antiinflammatory, hypoglycemic, hyperlipidemia, antimicrobial, antitumor, antioxidative, antiproliferative, antihypertensive, hepatoprotective, etc. The present study summarizes and discusses the phytochemical profile, pharmacological properties, and toxicological effects of the Vernonia plant.

Blood pressure lowering effects of Vernonia amygdalina Del. Aqueous fraction on hypertensive Wistar Kyoto rats.

OBJECTIVES: Vernonia amygdalina (VA) is a plant that consumed as vegetable by Indonesians contained numerous secondary metabolites. VA's pharmacological action, including its antioxidant properties, anticancer, antidiabetic, and hepatoprotective. The purpose of this research is to reveal the activity of Vernonia amygdalina. leafs aqueous fraction (VALAF) as a blood pressure-lowering agent in hypertensive model. METHODS: Combination of prednisone and NaCl were used as hypertensive inducer. The animals were split into five different groups, normal control group treated with distilled water, treatment VALAF groups with dose of 10; 20 and 40 mg/kg BW respectively, while the last group was treated with captopril at dose of 2.25 mg/kg BW. All animals were given an oral treatment for 15 days. On days 5, 10, and 15, systolic and diastolic blood pressure, heart rate (HR), mean arterial pressure (MAP), and blood flow (BF) were all measured. On days 0 and 15, NO level were assessed. All data were analyzed using two-way ANOVA, and Duncan Multiple Range Test. RESULTS: The V. amygdalina leaf aqueous fraction has blood pressure lowering activity. The blood pressure parameter of the rats treated with VALAF were lower as compared to the normal control group (p<0.05). NO levels in the VALAF group were not significantly higher than in the normal control group (p>0.05). The VALAF 20 give the greatest percentage of decrease in blood pressure, heart rate and blood volume on the 15th day of examination. CONCLUSIONS: These study indicated that V. amygdalina leaf aqueous fraction has the potential to be an alternative therapy for managing blood pressure in hypertensive animal models.

Polyoxygenated Stigmastane-Type Steroids from Vernonia kotschyana Sch. Bip. ex Walp. and Their Chemophenetic Significance.

Four polyoxygenated stigmastanes (1-4) alongside known analogues (7-8) and flavonoids (5-6) were isolated from a dichloromethane/methanol (1:1, v/v) extract of the whole plant of Vernonia kotschyana Sch. Bip. ex Walp. (Asteraceae). Their structures were determined by means of spectroscopic and spectrometric analysis. The relative stereochemistry of the new compounds was established and confirmed via biosynthesis evidence and cyclization of 1 under acidic conditions. A plausible biosynthetic pathway to the new compounds and the chemophenetic significance of the isolated constituents were also discussed. The crude extract, fractions, and compounds (1-3) were assessed for their antibacterial activity against five highly prevalent bacterial strains. The fractions and compounds showed low to moderate activity with minimal inhibitory concentrations (MICs) > 125 µg/mL.

Evaluation of the Antibacterial and Antibiofilm Effects of Ethyl Acetate Root Extracts from Vernonia adoensis (Asteraceae) against Pseudomonas aeruginosa.

There is an increase in mortality and morbidity in the health facilities due to nosocomial infections caused by multidrug-resistant nosocomial bacteria; hence, there is a need for new antibacterial agents. Vernonia adoensis has been found to possess medicinal value. Plant phytochemicals may have antimicrobial activity against some resistant pathogens. The antibacterial efficacy of root extracts against Staphylococcus aureus and Pseudomonas aeruginosa was investigated using the microbroth dilution method. All extracts from the roots had an inhibitory effect on the growth of both bacteria, with the most susceptible being P. aeruginosa. The most potent extract was the ethyl acetate extract which caused a percentage inhibition of 86% against P. aeruginosa. The toxicity of the extract was determined on sheep erythrocytes, and its effect on membrane integrity was determined by quantifying the amount of protein and nucleic acid leakage from the bacteria. The lowest concentration of extract used, which was 100 µg/ml, did not cause haemolysis of the erythrocytes, while at 1 mg/ml of the extract, 21% haemolysis was observed. The ethyl acetate extract caused membrane impairment of P. aeruginosa, leading to protein leakage. The effect of the extract on the biofilms of P. aeruginosa was determined in 96-microwell plates using crystal violet. In the concentration range of 0-100 µg/ml, the extract inhibited the formation of biofilms and decreased the attachment efficiency. The phytochemical constituents of the extract were determined using gas chromatography-mass spectrometry. Results of analysis showed the presence of 3-methylene-15-methoxy pentadecanol, 2-acetyl-6-(t-butyl)-4-methylphenol, 2-(2,2,3,3-tetrafluoropropanoyl) cyclohexane-1,4-dione, E,E,Z-1,3,12-nonadecatriene-5,14-diol, and stigmasta-5,22-dien-3-ol. Fractionation and purification will elucidate the potential antimicrobial compounds which are present in the roots of V. adoensis.

[Melanogenesis of quality markers in Vernonia anthelmintica Injection based on UPLC-Q-TOF-MS combined network pharmacology].

This study aimed to evaluate the biological effect and mechanism of Vernonia anthelmintica Injection(VAI) on melanin accumulation. The in vivo depigmentation model was induced by propylthiouracil(PTU) in zebrafish, and the effect of VAI on melanin accumulation was evaluated based on the in vitro B16F10 cell model. The chemical composition of VAI was identified according to the high-performance liquid chromatography quadrupole-time-of-flight tandem mass spectrometry(UPLC-Q-TOF-MS). Network pharmaco-logy was applied to predict potential targets and pathways of VAI. A "VAI component-target-pathway" network was established, and the pharmacodynamic molecules were screened out based on the topological characteristics of the network. The binding of active molecules to key targets was verified by molecular docking. The results showed that VAI promoted tyrosinase activity and melanin production in B16F10 cells in a dose-and time-dependent manner and could restore the melanin in the body of the zebrafish model. Fifty-six compounds were identified from VAI, including flavonoids(15/56), terpenoids(10/56), phenolic acids(9/56), fatty acids(9/56), steroids(6/56), and others(7/56). Network pharmacological analysis screened four potential quality markers, including apigenin, chrysoeriol, syringaresinol, and butein, involving 61 targets and 65 pathways, and molecular docking verified their binding to TYR, NFE2L2, CASP3, MAPK1, MAPK8, and MAPK14. It was found that the mRNA expression of MITF, TYR, TYRP1, and DCT in B16F10 cells was promoted. By UPLC-Q-TOF-MS and network pharmacology, this study determined the material basis of VAI against vitiligo, screened apigenin, chrysoeriol, syringaresinol, and butein as the quality markers of VAI, and verified the efficacy and internal mechanism of melanogenesis, providing a basis for quality control and further clinical research.

Melanogenesis of quality markers in Vernonia anthelmintica Injection based on UPLC-Q-TOF-MS combined network pharmacology / 中国中药杂志

This study aimed to evaluate the biological effect and mechanism of Vernonia anthelmintica Injection(VAI) on melanin accumulation. The in vivo depigmentation model was induced by propylthiouracil(PTU) in zebrafish, and the effect of VAI on melanin accumulation was evaluated based on the in vitro B16F10 cell model. The chemical composition of VAI was identified according to the high-performance liquid chromatography quadrupole-time-of-flight tandem mass spectrometry(UPLC-Q-TOF-MS). Network pharmaco-logy was applied to predict potential targets and pathways of VAI. A "VAI component-target-pathway" network was established, and the pharmacodynamic molecules were screened out based on the topological characteristics of the network. The binding of active molecules to key targets was verified by molecular docking. The results showed that VAI promoted tyrosinase activity and melanin production in B16F10 cells in a dose-and time-dependent manner and could restore the melanin in the body of the zebrafish model. Fifty-six compounds were identified from VAI, including flavonoids(15/56), terpenoids(10/56), phenolic acids(9/56), fatty acids(9/56), steroids(6/56), and others(7/56). Network pharmacological analysis screened four potential quality markers, including apigenin, chrysoeriol, syringaresinol, and butein, involving 61 targets and 65 pathways, and molecular docking verified their binding to TYR, NFE2L2, CASP3, MAPK1, MAPK8, and MAPK14. It was found that the mRNA expression of MITF, TYR, TYRP1, and DCT in B16F10 cells was promoted. By UPLC-Q-TOF-MS and network pharmacology, this study determined the material basis of VAI against vitiligo, screened apigenin, chrysoeriol, syringaresinol, and butein as the quality markers of VAI, and verified the efficacy and internal mechanism of melanogenesis, providing a basis for quality control and further clinical research.

Can Crude Oil Exploration Influence the Phytochemicals and Bioactivity of Medicinal Plants? A Case of Nigerian Vernonia amygdalina and Ocimum gratissimum.

The Nigerian Niger-Delta crude oil exploration often results in spills that affect indigenous medicinal plant biodiversity, likely changing the phytochemical profile of surviving species, their bioactivity or toxicity. In crude oil-rich Kokori and crude oil-free Abraka, classic examples of indigenous plants occupying the medicine-food interface include Vernonia amygdalina (VAL) and Ocimum gratissimum leaves (OGL). These plants are frequently utilised during pregnancy and in anaemia. To date, no scientific investigation has been reported on the potential changes to the phytochemical or bioactivity of the study plants. To discuss the similarities and dissimilarities in antisickling bioactivity and phytochemicals in VAL and OGL collected from Kokori (VAL-KK and OGL-KK) and Abraka (VAL-AB and OGL-AB), in silico, in vitro and comparative UPLC-QTOF-MS analysis was performed. Nine unique compounds were identified in OGL-KK, which have never been reported in the literature, while differences in antisickling potentials were observed in VAL-KK, OGL-KK and, VAL-AB, OGL-AB. Our findings show that VAL-AB and OGL-AB are richer and more diverse in phytochemicals and displayed a slightly higher antisickling activity than VAL-KK and OGL-KK. Ligand-based pharmacophore modelling was performed to understand the potential compounds better; this study may provide a basis for explaining the effect of crude oil spills on secondary metabolites and a reference for further research.

Rapid identification of stigmastane-type steroid saponins from Vernonia amygdalina leaf based on α-glucosidase inhibiting activity and molecular networking.

Steroid saponins are secondary metabolites with multiple medicinal values that are found in large quantities in natural medicines, especially Vernonia amygdalina, a famous nature medicine for the treatment of tonsillitis, diabetes, pneumonia. The current study was designed to combine molecular networking (MN) with diagnostic ions for rapid identification of Δ7,9(11) stigmastane-type saponins which were the α-glucosidase inhibitory active substances in V. amygdalina. First, the α-glucosidase inhibitory activities of five Δ7,9(11) stigmastane-type steroid saponins that were previously isolated were screened, which indicated that the Δ7,9(11) stigmastane-type steroid saponin was one of the active constituents responsible for ameliorating diabetes. Furthermore, a strategy was proposed to identify stigmastane-type steroid saponins and verify the plausibility of derived fragmentation pathways by applying MN, MolNetEnhancer and unsupervised substructure annotation (MS2LDA). Based on this strategy, other seven Δ7,9(11) stigmastane-type steroid saponins were identified from this plant. Our research provide scientific evidence for the antidiabetic potential of the steroid saponin-rich extract of V. amygdalina leaf.

Glycemic indices and effect of bitter leaf (Vernonia amygdalina) flavored non-alcoholic wheat beer (NAWB) on key carbohydrate metabolizing enzymes in high fat diet fed (HFD)/STZ-induced diabetic Wistar rats.

In a bid to make the use of functional food easier in the management and prevention of diseases, product development and fortification from/with functional foods have become the recent focus of research. This study, therefore, sought to exploit the recent trend in the brewing industry on the production of non-alcoholic beers by investigating the possibility of having a non-alcoholic beer flavored with bitter leaf, a known plant widely reported to have a strong hypoglycemic effect, as against the traditional use of hops, and the effect of the produced beer on the glycemic indices and various diabetic biochemical parameters that serve as biomarkers for type-2 diabetes (T2D). The glycemic indices, as well as the inhibitory potentials of bitter leaf-flavored Non-alcoholic wheat beer (NAWB) in ratios of 100%HP, 100%BL, 75:25BL, 50:50BL, and 25:75BL, on enzymes linked to a high-fat diet/streptozocin (HFD/STZ)-induced T2D albino Wistar rats were investigated. There were no significant difference (p > .05) between the starch (1.72-1.77 mg/100 mL), amylose (0.22-0.24 mg/100 mL), and amylopectin (1.49-1.53 mg/100 mL) contents of the various samples. The Glycemic Index (GI) of the samples ranged from 36 to 73 with 75:25Bl and 50:50BL have the lowest (36) values. The samples reduced blood glucose levels and inhibited pancreatic α-amylase, lipase, and intestinal α-glucosidase activity. The inhibitory potentials of these beer samples on α-amylase and α-glucosidase as well as their ability to reduce blood glucose levels in diabetic rats thus making the bitter leaf flavored NAWB a suitable healthy beverage for better glycemic control in diabetics. PRACTICAL APPLICATIONS: This study revealed the potential of producing non-alcoholic wheat beer flavored with bitter leaves as a possible substitute for hops. The potential inherent in bitter leaf in the management of type 2 diabetes can thus be made available through a far-reaching beverage medium such as non-alcoholic beer to help in the treatment/management of T2D. The results of this research could be an eye-opener to the possible utilization of bitter leaf and by extension other plants that have been reported in the management of T2D. The use of the bitter leaf as a substitute for hops in the production of non-alcoholic beer in the brewing industry could help in a health-oriented campaign for safe drinks that could be helpful in the control of blood glucose levels of diabetic patients.

Antimicrobial Evaluation of Sequentially extracted Leaf of Vernonia auriculifera Hiern (Rejicho).

BACKGROUND: Though there are reports about V. auriculifera antimicrobial activity, there is not enough information about its activity on some bacterial and fungal species. Besides, there was no quantitative evaluation done for phytochemicals previously. Therefore, the main purpose of this research work is to evaluate the antimicrobial activity and quantitative evaluation of the phenol and flavonoid contents of V. auriculifera. OBJECTIVES: The objective of this study was to conduct the antimicrobial and quantitative evaluation of a sequentially extracted leaf of Vernonia auriculifera Hiern. METHODS: The leaves of the plant were cleaned with tap water and air-dried. The grounded leaf product was subsequently extracted by hexane, chloroform, and methanol in maceration flasks. Then the total phenol and total flavonoid content in each extract were determined. Standard strains of bacterial and fungal species were used to assess the antibacterial, and antifungal susceptibility test and to determine the minimum inhibitory concentration of crude extract. RESULT: Extraction yield for hexane, chloroform, and methanol was 0.6 ± 0.05%, 1.7 ± 0.02%, and 3.3 ± 0.01% respectively. The total phenolic content of methanol extract was 72.998 ± 0.002 mg GAE /g. The total flavonoid content of hexane and chloroform extracts were 2.59 ± 0.004 mg QE/g and 9.6 ± 0.02 mg QE/g respectively. The antimicrobial activity test showed the chloroform extract was the most active against all test microorganisms. CONCLUSION: This study has shown the activity of V. auriculifera against selected microorganisms of study. The chloroform extract was the most active as compared to the hexane and methanol extracts.

Tautomeric phytosterols from Vernonia amygdalina Delile and their anti-cervical cancer activity.

Vernonia amygdalina Delile is generally used as green vegetables for cuisine in Nigeria and health tea or products in southeast of china. It was also used as folk medicine for the treatment of anti-helminth, febrifuge, digestive tonic and wounds. In this study, eleven undescribed phytosterols (1-2, 4-12) and six known analogues (3, 13-17) were isolated from the stems of V. amygdalina. Their structures including absolute configurations were elucidated by comprehensive spectroscopic methods (1D and 2D NMR, HRESIMS), X-ray diffraction and comparison of their ECD spectra. Besides, the tautomerism of phytosterols (1, 3-6, 12-17) with hemiacetal moiety were analyzed by solution NMR with different deuterated solvent and variable-temperature experiments. In addition, the cytotoxic activities of isolates against HeLa cells were evaluated. As a result, compound 10 exhibited the most potent anti-cervical cancer activity with the IC50 of 22.44 µM. Mechanism studies indicated that 10 triggered HeLa cells apoptosis through activating caspase signaling pathway. Furthermore, 10 could arrest the cell cycle in S phase and suppress the activation of the PI3K/AKT/mTOR pathway, leading to the inhibition of HeLa cells proliferation.

Rapid screening of natural-origin tyrosinase regulators from Vernonia anthelmintica (L.) Willd. by offline two-dimensional liquid chromatography coupled with mass spectrometry.

Finding and developing safe and effective tyrosinase (TYR) regulators is of great significance for the prevention and treatment of melanin-related skin diseases in the medical and cosmetic industries. In the current research, an approach based on offline two-dimensional liquid chromatography coupled with mass spectrometry (offline 2D LC-MS) was established to screen TYR modulators from Vernonia anthelmintica (L.) Willd. (VA) extract. Firstly, the reliability of the proposed method was evaluated by using kojic acid (inhibitor), psoralen (activator) and ranitidine as positive and negative control, respectively. Some significant parameters including incubation time, TYR concentrations, and reaction temperature were investigated. Then, the developed new method was successfully applied to rapidly discover the active compounds from VA extract. Seven TYR ligands were successfully screened by comparing the chromatographic profiles of VA extract incubated with active and denatured TYR, respectively. To verify the activity of the screened compounds, in vitro bioassay was carried out and the result showed two of them, isorhamnetin and luteolin, had good TYR inhibitory activity with IC50 value of 0.86 and 1.00 mg/mL, respectively, while the other five compounds including eriodictyol, butochalcone, chlorogenic acid, isochlorogenic acid B, and isochlorogenic acid C showed strong activation against TYR. Furthermore, molecular docking displayed that these compounds could bind to the amino acid residues in TYR catalytic pocket. The results demonstrate that the established technique can be efficiently used for rapid screening of TYR-active compounds from plant extracts.

Sesquiterpene Lactones from Vernonia tufnelliae: Structural Characterization and Biological Evaluation.

The genus Vernonia is an extremely rich source of biologically active sesquiterpene lactones. The present report describes the spectroscopic structure elucidation and the cytotoxic and antimicrobial properties of five hitherto unknown germacranolide-like sesquiterpenoids and several known compounds. These new derivatives include a compound (1) with an unprecedented 10/5/5/6 tetracyclic framework featuring a hexahydro-1H,3H,7H-furo[3',4':3,4]furo[3,2-c]pyridin-1-one core resulting from an intramolecular cyclization cascade involving a methacrylate substituent and a low molecular weight amine. Furthermore, an elemane-germacranolide hybrid (2) and three amino acid-derived lactones (3-5) were characterized. A plausible biosynthetic pathway to the key alkaloid is presented, while shielding tensor calculations using DFT in combination with the DP4+ method were applied to elucidate its stereostructure. The newly characterized compounds along with ten known sesquiterpene lactones and phenolic compounds have been isolated from Vernonia tufnelliae, a medicinal plant from the western region of Cameroon. Their structures were consistent with spectroscopic and spectrometric data recorded. The present report is the first investigation of the chemistry and biology of V. tufnelliae.

Antibacterial secondary metabolites from Vernonia auriculifera Hiern (Asteraceae) against MDR phenotypes.

Purification of the aerial parts of Vernonia auriculifera Hiern afforded steroids (1-2), flavonoids (3-5), and polyalcohol (6). Their structures were determined using spectral evidences as well as by comparison with reported data. Iodonitrotetrazolium chloride (INT) colorimetric assay was used to assess the antibacterial activity of the extract and isolates against 13 pathogenic strains. The crude extract showed strong antibacterial activity (MIC < 100 µg/mL) against the tested bacterial strains. When combined with an efflux pump inhibitor phenylalanine beta naphthylamide (PAßN), the inhibition potency of the extract was substantially enhanced with the lowest MIC value at 4 µg/mL. Compounds 5 and 6 showed moderate activity (MIC < 100 µg/mL) against 12/13 (92.3%), and 8/13 (61.5%) bacterial strains, respectively. A minimal bactericidal concentration (MBC)/minimal inhibitory concentration (MIC) ratio ≤ 4 indicated their bactericidal effect against Escherichia coli, Enterbacter aerogenes, Klebsiella pneumoniae, Providencia stuartii, Pseudomonas aeruginosa, and Staphylococcus aureus.

Vernonia amygdalina stimulates muscle glucose uptake and modulates redox activities and functional chemistry in oxidative hepatic injury.

The ethyl acetate, ethanol, and aqueous extracts sequentially obtained from the leaves of Vernonia amygdalina were investigated for their antidiabetic and antioxidant protective effect in oxidative hepatic injury. The extracts showed significant (p < .05) free radical scavenging and reducing power activities. They significantly (p < .05) elevated reduced glutathione level, superoxide dismutase, and catalase activities, with concomitant depletion of malondialdehyde level. The ethanol and aqueous extracts caused a removal of oxidative-included chemical functional group at 1,500-1,200 (amide II)/cm region, with the inclusion of a functional group at 3,000-2,800 (carboxylic acid)/cm region. The extracts significantly (p < .05) inhibited the activities of α-glucosidase and α-amylase and stimulated glucose uptake in rat muscles. Gas chromatography-mass spectrometric (GC-MS) analysis revealed phytol as the predominant compound, with ethanol having the highest concentration. Based on the IC50 values, the ethanol extract exhibited the best activities, followed by the ethyl acetate extract, while the aqueous extract was the least. These results suggest the antioxidative and antidiabetic properties of V. amygdalina as evident by their modulation of antioxidant biomarkers and oxidative-induced chemistry changes and stimulate muscle glucose uptake. PRACTICAL APPLICATIONS: Vernonia amygdalina (bitter leaf) is amongst the common leafy vegetables in West Africa reported for its various medicinal and nutritional properties. It is utilized as a food ingredient as well as supplement for the treatment and management of type 2 diabetes. The ability of its extracts to stimulate glucose uptake and protect against diabetic-induced changes in the chemical functional groups of the liver gives more credence to its reported antidiabetic properties. Being a common leafy vegetable, V. amygdalina can be a cheap source of nutraceutical for the treatment and management of type 2 diabetes and its complications.

In vitro Anticancer Effects of Vernonia amygdalina Leaf Extract and Green-Synthesised Silver Nanoparticles.

PURPOSE: Vernonia amygdalina (VA) is a traditional African herbal medicine that has been reported to possess anticancer properties. However, the anticancer properties of VA silver nanoparticles have not been studied. The aim of the study was to examine and evaluate the anticancer activities of VA leaf extracts and VA silver nanoparticles on the human breast cancer cell line, MCF-7. METHODS: VA leaves were extracted using sequential extraction assisted with ultrasound using three different solvents: ethanol, 50% ethanol, and deionized water. The silver nanoparticles were synthesised with VA aqueous extract. RESULTS: The ethanol extract and VA silver nanoparticles inhibit MCF-7 cell proliferation with an average half-maximal inhibitory concentration (IC50) value of 67µg/mL and 6.11µg/mL, respectively, after 72 hours of treatment. The ethanol extract and VA silver nanoparticles also caused G1 phase cell cycle arrest, induced apoptosis and nuclear fragmentation in MCF-7 cells. CONCLUSION: VA ethanol extracts and VA silver nanoparticles decreased the cell viability in MCF-7 cells in a time and dose-dependent manner by inducing apoptosis and causing DNA damage. Further research is needed to elucidate the mechanism of action of VA leaf extracts and VA silver nanoparticles. This study is the first to report on the anticancer activity of VA silver nanoparticles in MCF-7 cells.

The Great Capacity on Promoting Melanogenesis of Three Compatible Components in Vernonia anthelmintica (L.) Willd.

To investigate a possible methodology of exploiting herbal medicine and design polytherapy for the treatment of skin depigmentation disorder, we have made use of Vernonia anthelmintica (L.) Willd., a traditional Chinese herbal medicine that has been proven to be effective in treating vitiligo. Here, we report that the extract of Vernonia anthelmintica (L.) Willd. effectively enhances melanogenesis responses in B16F10. In its compound library, we found three ingredients (butin, caffeic acid and luteolin) also have the activity of promoting melanogenesis in vivo and in vitro. They can reduce the accumulation of ROS induced by hydrogen peroxide and inflammatory response induced by sublethal concentrations of copper sulfate in wild type and green fluorescent protein (GFP)-labeled leukocytes zebrafish larvae. The overall objective of the present study aims to identify which compatibility proportions of the medicines may be more effective in promoting pigmentation. We utilized the D-optimal response surface methodology to optimize the ratio among three molecules. Combining three indicators of promoting melanogenesis, anti-inflammatory and antioxidant capacities, we get the best effect of butin, caffeic acid and luteolin at the ratio (butin:caffeic acid:luteolin = 7.38:28.30:64.32) on zebrafish. Moreover, the effect of melanin content recovery in the best combination is stronger than that of the monomer, which suggests that the three compounds have a synergistic effect on inducing melanogenesis. After simply verifying the result, we performed in situ hybridization on whole-mount zebrafish embryos to further explore the effects of multi-drugs combination on the proliferation and differentiation of melanocytes and the expression of genes (tyr, mitfa, dct, kit) related to melanin synthesis. In conclusion, the above three compatible compounds can significantly enhance melanogenesis and improve depigmentation in vivo.