Isolation and structure determination of a sesquiterpene lactone (vernodalinol) from Vernonia amygdalina extracts

Context: Vernonia amygdalina Del. (VA; Asteraceae or Compositae) is a small tree growing throughout tropical Africa. It is widely used for food and medicinal purposes by local people. It was reported that it had several qualities, including anticancer activity.

Objective: A sesquiterpene lactone, vernodalinol, was isolated from VA leaves. The first reported source of vernodalinol was in 2009 from a different plant, only ¹H NMR spectrum and no detailed structural analysis were carried out. No whole spectroscopic data were provided.

Materials and methods: VA dried leaves were extracted with 85% ethanol followed by further separation into four fractions by liquid–liquid extraction technique using various solvents: hexane, chloroform, and n-butanol. Vernodalinol was separated from the n-butanol fraction by column chromatography. The biological activity of vernodalinol was evaluated in estrogen receptor-positive (ER⁺) human breast carcinoma cells (MCF-7) in vitro.

Results: Results indicated that vernodalinol (25 and 50 μg/mL) inhibited breast cancerous cell growth (DNA synthesis) by 34% (P?<?0.025) and 40% (P?<?0.025), respectively. It is reasonable to expect an LC₅₀ of 70–75 μg/mL for vernodalinol in MCF-7 cells.

Discussion and conclusion: Vernodalinol structure was confirmed using a battery of spectroscopic methods, 1D and 2D NMR, high-resolution mass spectrometry (HR-MS), UV, IR, and X-ray. These results suggest that vernodalinol, although it has some biological activity, is likely to work in concert with other ingredients responsible for the anticancer activity exhibited of VA.     

Vasorelaxant properties of Vernonia amygdalina ethanol extract and its possible mechanism

Context: Vernonia amygdalina Del. (VA) (Asteraceae) is commonly used to treat hypertension in Malaysia.

Objective: This study investigates the vasorelaxant mechanism of VA ethanol extract (VAE) and analyzes its tri-step FTIR spectroscopy fingerprint.

Materials and methods: Dried VA leaves were extracted with ethanol through maceration and concentrated using rotary evaporator before freeze-dried. The vasorelaxant activity and the underlying mechanisms of VAE using the cumulative concentration (0.01–2.55?mg/mL at 20-min intervals) were evaluated on aortic rings isolated from Sprague Dawley rats in the presence of antagonists.

Results: The tri-step FTIR spectroscopy showed that VAE contains alkaloids, flavonoids, and saponins. VAE caused the relaxation of pre-contracted aortic rings in the presence and absence of endothelium with EC₅₀ of 0.057?±?0.006 and 0.430?±?0.196?mg/mL, respectively. In the presence of Nω-nitro-l-arginine methyl ester (EC₅₀ 0.971?±?0.459?mg/mL), methylene blue (EC₅₀ 1.203?±?0.426?mg/mL), indomethacin (EC₅₀ 2.128?±?1.218?mg/mL), atropine (EC₅₀ 0.470?±?0.325?mg/mL), and propranolol (EC₅₀ 0.314?±?0.032?mg/mL), relaxation stimulated by VAE was significantly reduced. VAE acted on potassium channels, with its vasorelaxation effects significantly reduced by tetraethylammonium, 4-aminopyridine, barium chloride, and glibenclamide (EC₅₀ 0.548?±?0.184, 0.158?±?0.012, 0.847?±?0.342, and 0.304?±?0.075?mg/mL, respectively). VAE was also found to be active in reducing Ca²⁺ released from the sarcoplasmic reticulum and blocking calcium channels.

Conclusions: The vasorelaxation effect of VAE involves upregulation of NO/cGMP and PGI₂ signalling pathways, and modulation of calcium/potassium channels, and muscarinic and β₂-adrenergic receptor levels.     

Pharmacological Activities of Vernonia glabra

A 70% methanol aerial part extract of Vernonia glabra caused a fall in blood pressure in anaesthetised rats. After the 50 µg dose, systolic, diastolic, and mean blood pressures decreased by 56%, 66%, and 61% respectively below the baseline levels. The adrenaline-like activity of the extract was not antagonised by L(-) propranolol on isolated rabbit heart. The extract caused contraction on the isolated rabbit ileum and was abolished with atropine, suggesting the presence of a compound with acetylcholine-like activity. The extract on isolated guinea pig ileum caused contraction which was dose related.     

Assessment of the Anthelmintic Efficacy of an Aqueous Crude Extract of Vernonia amygdalina.

Abstract

The anthelmintic efficacy of an aqueous crude extract of the leaves of Vernonia amygdalina. Del. (Compositae) was studied in 16 Nigerian puppies. They were divided into four groups of four puppies per group. The group A animals were uninfected and hence were untreated, whereas those in groups B, C, and D were naturally infected with helminths. Group B animals were untreated whereas group C animals were treated with a proprietary anthelmintic (Mebendazole). Group D animals were treated with aqueous crude extracts of V. amygdalina. using the oral route. Two weeks after treatment, blood and fecal samples were collected to evaluate the hematologic values and fecal egg counts, respectively. Before the onset of this study, fecal egg counts showed that ascarids (Toxocara canis.) and hookworm (Ancylostoma caninum.) were present in the experimental animals. The results of this study showed that the aqueous crude extracts of V. amygdalina. after its administration into local dogs produced significant changes (p < 0.05) in PCV, RBC, Hb concentration, and TWBC. The fecal egg counts also showed remarkable and significant reduction in the levels of the identified helminths. The effects of the plant extracts were broad spectrum in action. Because the aqueous crude extract of V. amygdalina. significantly reduced the fecal egg count of the helminths, it could be a potential source of a new lead anthelmintic agent.     

Biologically Active Substances from the Genus Scrophularia

Scrophularia species have been used since ancient times as folk remedies for some medical treatments including scrophula, scabies, tumours and inflammatory affections. Some compounds isolated from these species, such as iridoids and phenylpropanoids, are considered responsibles for these activities. This review summarizes mainly the biological activity associated with this genus.     

Biologically Active Compounds from the Genus Hibiscus.

Abstract

Since ancient times, Hibiscus. species (Malvaceae) have been used as a folk remedy for the treatment of skin diseases, as an antifertility agent, antiseptic, and carminative. Some compounds isolated from the species, such as flavonoids, phenolic acids, and polysaccharides, are considered responsible for these activities. This review aims to summarize the worldwide reported biological activities and phytoconstituents associated with this genus for the past 40 years.     

Aqueous and methanol extracts of Vernonia amygdalina leaves exert their anti-obesity effects through the modulation of appetite-regulatory hormones

Context: Aqueous and methanol extracts of Vernonia amygdalina Del. (Asteraceae) (AEVA and MEVA, respectively) leaves are reported to possess anti-obesity properties, exerted through unknown mechanisms.

Objective: This study investigated the effects of AEVA and MEVA on relevant hormones and enzymes in high-fat diet (HFD)-induced obese rats.

Materials and methods: Forty-two Wistar rats were placed into seven groups. The test groups received 100?mg/kg.bw AEVA (AEVA100), 500?mg/kg.bw AEVA (AEVA500), 50?mg/kg.bw MEVA (MEVA50) and 200?mg/kg.bw MEVA (MEVA200), respectively. The positive control (PC) group received 20?mg/kg.bw Orlistat, while the negative control (NeC) and normal control (NoC) groups received distilled water. The extracts were given orally daily for 12 weeks. Thereafter, the concentrations/activities of relevant hormones/enzymes in their sera were determined.

Results: Insulin concentrations (ng/ml) in the test groups ranged from 1.08?±?0.01 (AEVA100) to 1.09?±?0.01 (AEVA500). They were all similar (p?>?.05) to the NoC and PC controls. Leptin concentrations (pg/ml) in the test rats ranged from 0.02?±?0.01 (AEVA500) to 0.03?±?0.00 (MEVA50), and were all similar to the NoC group. The ghrelin concentrations of only the AEVA500 and MEVA200 groups were similar to those of the PC group (0.10?±?0.01?pg/ml). AEVA100 and MEVA200 resulted in adiponectin concentrations (ng/ml) of the rats (0.27?±?0.04 and 0.28?±?0.04 respectively) that were similar to the PC group. The activities of lipoprotein lipase and the concentrations of intestinal amylase in the test rats were similar to values obtained for the control groups.

Conclusion: Appetite regulation may be the mechanism through which the weight-loss properties of AEVA and MEVA are expressed.     

Biologically Active Substances in the Aqueous Fraction of Alfredia cernua (L.) Cass. Extract Possessing Antiamnesic Properties

Pharmaceutical Chemistry Journal - The composition of biologically active substances in the aqueous total fraction of the 95% EtOH extract of the aerial part of Alfredia cernua (L.) Cass....     

Biologically Active Alkaloids from Poison Frogs (Dendrobatidae)

Abstract

A total of over one hundred biologically active alkaloids have been characterized in skin extracts from dendrobatid frogs. Five major classes have been defined: The highly toxic batrachotoxins are steroidal alkaloids which prevent interactivation of sodium channels in nerve and muscle. Pumiliotoxin-C class alkaloids are decahydroquinolines which block nicotinic receptor mediated neuromuscular transmission. Histrionicotoxins are spiropiperidines which block chemosensitive channels and potassium channels. The pumiliotoxin-A class alkaloids are 6-alkylidene-indolizidines which facilitate calcium-dependent excitation-contraction and excitation-secretion coupling. The gephyrotoxins are indolizidines and perhydrobenzoindolizidines. Gephyrotoxin is a muscarinic antagonist.     

New Vernolepin Derivatives from Vernonia glabra and Glaucolides from Vernonia scorpioides

The aerial parts of VERNONIA GLABRA afforded in addition to vernolepin, vernodalin and vernomenin, four further sesquiterpene lactones derived from vernolepin ( 1), two germacranolides and together with vernodalol the corresponding lactone 9. From VERNONIA SCORPIOIDES two further glaucolides ( 14) and ( 15) were isolated. The structure of the tiglate ( 16) is revised. The structure were elucidated by spectroscopic methods.     

生物活性环肽及其药学研究进展

环肽是植物来源的超稳定肽,由头至尾环化骨架和形成胱氨酸结的3个二硫键非常稳定。与其他类似大小的肽相比,环肽的这种独特的拓扑学结构使它们对化学、热和生物降解异常稳定,它们出色的稳定性和对序列替换的耐受性可使它们用作药物设计的框架。本文主要介绍了环肽在药学研究领域3个方面的应用,特别是近年来在将生物活性肽序列嫁接到环肽的框架上,以产生新的生物学活性方面的研究进展。     

蓝藻中生物活性物质的研究概况

蓝藻中含有大量的生物活性物质。文章综述了近20年来从蓝藻中发现的各种生物活性物质以及它们可能的相关应用。     

黑骨藤活性部位抗炎与免疫调节作用研究

目的从黑骨藤（HGT）中分离筛选免疫抗炎活性部位,探讨其抗炎及免疫调节作用,为研制和开发新药提供实验依据。方法应用巴豆油诱发的急性小鼠耳肿胀及二硝基氯苯（DNCB）诱发的小鼠迟发型超敏反应（DTH）作为免疫抗炎活性的评价指标,观察HGT 5A对急性炎症及细胞免疫反应的影响。结果HGT 5A 100～500 mg&#8226;kg 1灌胃给药对巴豆油诱发的小鼠急性耳肿胀具有明显抑制作用,50～100 mg&#8226;kg 1灌胃给药对DNCB诱导的DTH反应具有明显抑制作用,并且对DTH模型小鼠脾细胞增殖反应均具有明显抑制作用。结论HGT 5A具有较明显的抗炎和免疫调节作用。     

Preparation and Effectiveness of Biologically Active Polypeptides from Fetal Bones for Stimulation of Chondrogenesis

Pharmaceutical Chemistry Journal - A biologically active complex of polypeptides was obtained from fetal bone to stimulate chondrogenesis. Its effectiveness was studied on the model of cartilage...