In vitro antimicrobial and antioxidant activities, essential oil composition, and in silico molecular modeling analysis of secondary metabolites from roots of Verbascum sinaiticum.

Verbascum sinaiticum is locally used to treat wound, stomachache, viral infection, cancer, sunstroke fever, abdominal colic, diarrhea, hemorrhage, anthrax, and hepatitis. The objective of this study was to identify the compounds and to evaluate the antimicrobial and antioxidant activity of the extracts and isolated compounds from V. sinaiticum. The 1H-NMR, 13C-NMR, and DEPT-135 were used to elucidate the structures of isolated compounds. Essential oils were extracted by hydrodistillation method and their chemical analyses were performed by GC-MS. The broth microdilution method was used to evaluate the antimicrobial activity. The radical scavenging activity of the extracts and isolated compounds were evaluated using DPPH method. Silica gel column chromatographic separation of root extracts afforded seven known compounds: 3'-(4''-methoxy phenyl)-3'-oxo-propionyl hexadecanoate (1), harpagoside (2), pulverulentoside I (3), scrophuloside B4 (4), scropolioside A (5), scropolioside-D2 (6), and harpagide 6-O-ß-glucoside (7), which are all reported from this species for the first time. The EO extracts from leaves and roots were the most susceptible to Streptococcus agalactiae, with a 2 mg/mL MIC. The EO from roots was effective against Candida albicans and Trichophyton mentagrophytes, with a MIC of 8 mg/mL. The MeOH and CH2Cl2/CH3OH (1:1) root extracts showed the maximum activity against S. epidermidis with MIC values of 0.25 mg/mL. The strongest antibacterial effects were demonstrated against Staphylococcus epidermidis, which exhibited a 0.0625 mg/mL MIC for compound 1. The strongest radical scavenging activity was exhibited by the methanol extract (IC50 = 3.4 µg/mL), and compounds 4, 6, 5, 3, 7, and 2 with IC50 values of 3.2, 3.38, 3.6, 3.8, 4.2, and 4.7 µg/mL, respectively, in comparison with ascorbic acid (IC50 = 1.3 µg/mL). The results of the molecular docking analysis of compounds revealed minimal binding energies range from -38.5 to -43.1 kJ/mol, -33.1 to -42.7 kJ/mol, -34.7 to -39.3.7 kJ/mol, -25.5 to -37.6 kJ/mol against human myeloperoxidase (PDB ID: 1DNU), murA enzyme (PDB ID: 1UAE), human topoisomerase IIß (PDB ID: 4fm9), S. epidermidis FtsZ (PDB number: 4M8I) proteins, respectively. The docking results and the in vitro antibacterial activity are in good agreement. These findings show that the isolated compounds 2-7 can act as potential antioxidants and strong antibacterials against Staphylococcus aureus and S. epidermidis. As a result, V. sinaiticum root extracts have the potential to be effective in treating diseases caused by bacteria and free radicals, as long as further investigation has been suggested for the ultimate decision of this plant's potential candidate.

Analyzing the Antioxidant Activity and Fatty Acid Composition of Monofloral Mullein (Verbascum sp.) Pollen Oil obtained via Various Extraction Techniques.

This study focused on characterizing fatty acids and evaluating the antioxidant properties in oils extracted from mullein (Verbascum sp.) bee-collected pollen, utilizing soxhlet and ultrasound-assisted methods with acetone and hexane solvents. Soxhlet extraction demonstrated high efficiency in mullein bee pollen oil extraction. The highest levels of total phenolic content (TPC), total flavonoid content (TFC), DPPH⋅, and ABTS⋅+ activities (41.07±1.43 mg GAE/g extract; 1.86±0.01 mg QE/g extract; 16.23±0.68 mg TE/g extract; 56.88±0.43 mg TE/g extract, respectively) were observed in oil extracted using the soxhlet method with acetone solvent. Conversely, ultrasound-assisted extraction with hexane yielded oils rich in saturated fatty acids, while acetone extraction contained higher monounsaturated fatty acids. Palmitic, linoleic, and oleic acids were predominant in the extracted oils. This study introduces, for the first time, the identification of fatty acids found in mullein bee pollen oil, along with an examination of their antioxidant properties. The choice of solvent was found to significantly influence compound extraction compared to the extraction method.

Verbascum species as a new source of saffron apocarotenoids and molecular tools for the biotechnological production of crocins and picrocrocin.

Crocins are glucosylated apocarotenoids present in flowers and fruits of a few plant species, including saffron, gardenia, and Buddleja. The biosynthesis of crocins in these plants has been unraveled, and the enzymes engineered for the production of crocins in heterologous systems. Mullein (Verbascum sp.) has been identified as a new source of crocins and picrocrocin. In this work, we have identified eight enzymes involved in the cleavage of carotenoids in two Verbascum species, V. giganteum and V. sinuatum. Four of them were homologous to the previously identified BdCCD4.1 and BdCCD4.3 from Buddleja, involved in the biosynthesis of crocins. These enzymes were analyzed for apocarotenogenic activity in bacteria and Nicotiana benthamiana plants using a virus-driven system. Metabolic analyses of bacterial extracts and N. benthamiana leaves showed the efficient activity of these enzymes to produce crocins using ß-carotene and zeaxanthin as substrates. Accumulations of 0.17% of crocins in N. benthamiana dry leaves were reached in only 2 weeks using a recombinant virus expressing VgCCD4.1, similar to the amounts previously produced using the canonical saffron CsCCD2L. The identification of these enzymes, which display a particularly broad substrate spectrum, opens new avenues for apocarotenoid biotechnological production.

Ferruginoside†D: A Novel Phenylethanoid from Verbascum leiocarpum.

A novel phenylethanoid, ferruginoside D, together with fourteen known compounds were isolated from the Verbascum leiocarpum for the first time. Chemical structures of isolated compounds were determined by spectroscopic analysis including HR-ESI-MS and NMR spectra. The antioxidant, α-glucosidase inhibitory properties, and antiproliferative activities against multiple cell lines (A172, C6, HeLa, A2780, SW620, HT29, Beas2B, RPE, and HSF) of the isolated compounds were evaluated in vitro. According to the results, iridoids, flavonoids (luteolin and apigenin), and phenylethanoids (poliumoside and isoverbascoside) with strong antiproliferative potential were also found to have cytostatic effects. Furthermore, the investigation revealed that compounds luteolin, poliumoside, verbascoside, isoverbascoside, ferruginoside C, ferruginoside D, and ursolic acid show potent alpha-glucosidase inhibitory activity, while compounds luteolin, verbascoside, and isoverbascoside exhibit substantial antioxidant activity. The new compound (ferruginoside D) was found moderately active against cancer cell lines, with strong alpha-glucosidase inhibitory activity, and moderate antioxidant properties.

Bioactive Compounds of Verbascum sinuatum L.: Health Benefits and Potential as New Ingredients for Industrial Applications.

Verbascum sinuatum (V. sinuatum) is a plant belonging to the Scrophulariaceae family that has been used as an ingredient in traditional medicine infusions for the treatment of many diseases. The aerial part of this plant is a source of bioactive compounds, especially polyphenols and iridoids. Moreover, antioxidant activity studies have shown that V. sinuatum phenolic and flavonoid composition is higher than those in other plants of the same genus. V. sinuatum bioactive compound composition could vary according to the harvesting location, growing conditions of the plants, sample preparation methods, type and concentration of the extraction solvent, and the extraction methods. The obtention of these compounds can be achieved by different extraction techniques, most commonly, maceration, heat assisted extraction, and infusion. Nevertheless, since conventional extraction techniques have several drawbacks such as long times of extraction or use of large amounts of solvents, the use of green extraction techniques is suggested, without affecting the efficiency of the extraction. Moreover, V. sinuatum bioactive compounds have several biological activities, such as antioxidant, anticancer, cardiovascular, antimicrobial, antidiabetic, and neuroprotective activities, that may be increased by encapsulation. Since the bioactive compounds extracted from V. sinuatum present good potential as functional food ingredients and in the development of drugs or cosmetics, this review gives an approach of the possible incorporation of these compounds in the food and pharmacological industries.

Isolation, characterization and anticancer activity of secondary metabolites from Verbascum speciosum.

Herein, two iridoid glucosides aucubin (1) and ajugol (2), and two phenyl ethanoids, verbascoside (3) and poliumoside (4) were isolated from the methanol extract of the aerial parts of Verbascum speciosum and used to study about their anticancer activity for the first time. The structures of all compounds were elucidated using spectroscopic data (IR, 1D and 2D NMR, LC-TOF/MS). Antiproliferative activities of Aucubun (1) and Verbascoside (3) were tested against A-549 (human colon cancer), MDA-MD-453 (human breast cancer) and 3T3-L1 (mouse fibroblast)cell lines by XTT assay. In addition, the anticarcer mechanism of action of aucubin (1) was investigated on MDA-MB-453 cells for the first time. XTT result showed that both applied compounds exhibited antiproliferative effect at different dose ranges depending on the cancer type, as well as selectivity between cancer and healty cell lines. Flow cytometry analyzes revealed that aucubin (1) exerts its cytotoxic effect in MDA-MB-453 cells by directing cells to early apoptosis and inhibiting the P13K/AKT signaling pathway.

Antioxidant, AChE inhibitory, and anticancer effects of Verbascum thapsus extract.

Verbascum thapsus (VT) is a medicinal plant that is used in folk medicine to treat a variety of ailments. For this study, the biological functions of VT methanol extract were determined in vitro. The plant's methanol extract was created through the maceration process. The phytochemical composition of plant extracts was investigated using liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). The antioxidant capacity of the extract was determined using the DPPH (2,2-diphenyl-1-picrylhydrazil) and ABTS (2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) tests and its cytotoxicity was assessed using the MTT ((3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, a tetrazole)) assay on the Caco-2 (human colorectal adenocarcinoma cells), LNCaP (Lymph Node Carcinoma of the Prostate), and HEK293 cell lines (Human embryonic kidney 293 cells) used to model colon, prostate, and non-cancerous cells. VT extract showed low DPPH and ABTS radical scavenging activities compared to standard antioxidants at 30 mg/ml concentration. In addition, it was determined that VT extract inhibited acetylcholinesterase enzyme.

Health-promoting and disease-mitigating potential of Verbascum thapsus L. (common mullein): A review.

Medicinal plants represent rich sources of traditional medicines and numerous currently used medicines are either directly or indirectly derived from plants. Verbascum thapsus L. (great mullein or common mullein), a medicinal herb indigenous to northern Africa, western and central Asia, and Europe, has been brought to the Americas and Australia. It has been used as a medicine for lung, skin and throat disorders and has a long history of therapeutic importance, particularly as an astringent and calming agent. Presently, the dried leaves, flowers, various plant extracts and flower oil are used in several formulations within Indian traditional medicine. An extract taken from the roots is useful in minimizing toothache, and it also relieves stiffness and seizures. V. thapsus contains a wide variety of phytoconstituents, such as flavonoids, iridoid, phenylethanoid and phenylpropanoid glycosides, saponins, as well as vitamin C and minerals. The most valuable constituents are coumarin and hesperidin, which possess healing properties. Emerging literature based on experimental studies on V. thapsus demonstrates various biological and pharmacological properties, including antiviral, antioxidant, analgesic, sedative, anti-inflammatory, hypnotic, antibacterial, antifungal, as well as anticancer activities. The present review provides an updated, comprehensive, and critical evaluation of various health-promoting and disease-mitigating properties of V. thapsus.

Phenolic and flavonoid compounds and antioxidant activity in flowers of nine endemic Verbascum species from Iran.

BACKGROUND: In this study, flowers of nine mullein species (Verbascum erianthum, V. songaricum, V. speciosum, V. szovitsianum, V. stachydiforme, V. sinuatum, V. haussknechtianum, V. cheirantifolium, and V. saccatum) were collected from Iran. The total flavonoid content (TFC), antioxidant activity, total carotenoid (TCC), ß-carotene content and the amount of phenolic compounds were determined in all of the collected mullein species. Quantitative analysis of phenolic compounds was performed using high-performance liquid chromatography with diode-array detection (HPLC-DAD). RESULTS: Verbascum saccatum and V. songaricum, in particular, were found to be rich in total flavonoids and exhibited the highest antioxidant capacity. The HPLC-DAD analysis revealed that V. erianthum possessed the highest amount of caffeic acid (0.022 g kg-1 DW), chlorogenic acid (2.649 g kg-1 DW), p-coumaric acid (0.253 g kg-1 DW), and apigenin (0.066 g kg-1 DW). The highest gallic acid (0.134 g kg-1 DW), rutin (5.254 g kg-1 DW), quercetin (1.303 g kg-1 DW), and cinnamic acid (1.031 g kg-1 DW) content were observed in V. saccatum. Our results demonstrate the considerable variations in the TFC, antioxidant activity, TCC, and ß-carotene content among the mullein species. CONCLUSIONS: The findings of this study provide useful information for breeding strategies, and for choosing the best species with high phenolic compound content to produce natural antioxidants for medical and pharmaceutical use. © 2021 Society of Chemical Industry.

Evaluation of antioxidant, cytotoxic, antibacterial effects and mineral levels of Verbascum lasianthum Boiss. ex Bentham.

The present study aimed to determine the antibacterial, antioxidant, cytotoxic activities and element levels of Verbascum lasianthum Boiss. ex Bentham. The free radical scavenging activity, total phenolic content, total antioxidant capacity, total oxidant capacity levels were analyzed as the antioxidant parameters. Seven bacteria and one yeast strains were used to determine the antimicrobial activity. The cytotoxic effects of plant extracts were determined using A549, MCF-7, HepG2 and SH-SY5Y cell lines. The findings demonstrated that the antioxidant activity increased with an increase in the phenolic content of extracts. This species is rich in bio-elements such as Fe, Cu, Mn, Zn, and Mg. Different concentrations of extracts could have antibacterial activity. This plant had an apparent cytotoxic effect only in the A549 cell line and increased the proliferation in other cell lines. The findings demonstrated that plant could be used alone or as a supplement to the current treatment protocols in diseases due to their antioxidant, antibacterial and cytotoxic effects. However, it is recommended that Verbascum L. species intended for use in therapy should be procured from areas where there is no soil pollution or organic farming is preferred.

Verbascum nigrum: Cytotoxicity Evaluation in A431 Epidermoid Carcinoma Cells and Untargeted LC-HR-MS/MS Metabolite Profiling.

The crude methanolic extract obtained from Verbascum nigrum aerial parts (VNE) and its six fractions (VNF1-VNF6) were initially screened regarding their effects on the viability of immortalized HaCaT keratinocytes and A431 epidermoid carcinoma cells (MTT assay, 24 h). None of the tested samples affected the viability of HaCaT cells in a concentration range of 25-150 µg/mL. VNE and VNF4 exhibited significant cytotoxic effects in A431 cells, with IC50 values of 81.92 and 12.27 µg/mL, respectively; the selectivity index was higher than 10 for VNF4. The untargeted LC/HR-MS/MS metabolite profiling led to the tentative annotation of a total number of 23 compounds. Of these, VNE comprised mainly iridoid glycosides (harpagoside, laterioside, acylated aucubin derivatives), whereas VNF4 showed a high abundance of triterpene saponin glycosides (ilwensisaponins A and C, songarosaponins A and B), constituents known for their selective cytotoxic potential.

6-O-(3″, 4″-di-O-trans-cinnamoyl)-α-l-rhamnopyranosylcatalpol and verbascoside: Cytotoxicity, cell cycle kinetics, apoptosis, and ROS production evaluation in tumor cells.

The aim of this study was to evaluate the impact that 6-O-(3″, 4″-di-O-trans-cinnamoyl)-α- l-rhamnopyranosylcatalpol (Dicinn) and verbascoside (Verb), two compounds simultaneously reported in Verbascum ovalifolium, have on tumor cell viability, apoptosis, cell cycle kinetics, and intracellular reactive oxygen species (ROS) level. At 100 µg/mL and 48 hours incubation time, Dicinn and Verb produced good cytotoxic effects in A549, HT-29, and MCF-7 cells. Dicinn induced cell-cycle arrest at the G0 /G1 phase and apoptosis, whereas Verb increased the population of subG1 cells and cell apoptosis rates. Furthermore, the two compounds exhibited time-dependent ROS generating effects in tumor cells (1-24 hours). Importantly, no cytotoxic effects were induced in nontumor MCF-10A cells by the two compounds up to 100 µg/mL. Overall, the effects exhibited by Verb in tumor cells were more potent, which can be correlated with its structural features, such as the presence of phenolic hydroxyl groups.

The Antioxidant, Anticarcinogenic and Antimicrobial Properties of Verbascum thapsus L.

BACKGROUND: The antioxidant, anticarcinogenic, and antimicrobial activities of Verbascum Thapsus L., known as great mullein, (an important medicinal plant containing different biochemical compounds including sesquiterpenes, flavonoids, saponins and lignins) were determined. There is not much data, to our knowledge, in this respect. METHODS: The antioxidant activities of V. Thapsus were investigated by the DPPH (2, 2- diphenyl- 1-picrylhydrazyl) method. Using GC-MS, the presence of different anticarcinogenic products including 1-hexzanol (2.11%), 2-hexene (1.95%), etc. was determined in the ethanolic extract of V. Thapsus. The antimicrobial activities of V. Thapsus were determined by the minimum inhibiting concentration (MIC) and minimum bactericidal concentration (MBC) methods using the Grampositive and -negative bacterial strains. RESULTS: The least concentration of V. Thapsus L. ethanolic extract (50 mg/l) resulted in only 21.26% inhibition of DPPH free radicals, however, the concentrations of 300 mg/l resulted in almost the highest inhibition (91.31%) of DPPH free radicals. The antioxidant activities of synthesized antioxidant BHT at the concentration of 300 mg/l or higher were similar to the antioxidant activities of V. Thapsus L. ethanolic extract. Both the isolated and the standard Gram-negative bacterial strains were more tolerant to the V. Thapsus ethanolic extract, compared with the Grampositive bacterial strains. Bacillus cereus was the most sensitive bacterial strain among the tested bacterial strains. CONCLUSION: The medicinal plant V. Thapsus L. can be used for the treatment of different diseases, such as cancer and infectious diseases.

Inhibition of Amyloid ß Aggregation Using Optimized Nano-Encapsulated Formulations of Plant Extracts with High Metal Chelator Activities.

BACKGROUND: The role of Fe+2, Cu+2 and Zn+2 in facilitating aggregation of Amyloid ß (Aß) and consequently, the progression of Alzheimer's disease (AD) is well established. OBJECTIVE: Development of non-toxic metal chelators is an emerging era in the treatment of AD, in which complete success has not been fully achieved. The purpose of this study was to determine plant extracts with high metal chelator and to encapsulate them in nano-micellar systems with the ability to pass through the Blood Brain Barrier (BBB). METHODS: Extracts of 36 different Anatolian plants were prepared, total phenolic and flavonoid contents were determined, and the extracts with high content were examined for their Fe+2, Cu+2 and Zn+2 chelating activities. Apolipoprotein E4 (Apo E) decorated nano-formulations of active extracts were prepared using Poly (Lactide-co-Glycolide) (PLGA) (final product ApoEPLGA) to provide BBB penetrating property. RESULTS: Verbascum flavidum aqueous extract was found as the most active sample, incubation of which, with Aß before and after metal-induced aggregation, resulted in successful inhibition of aggregate formation, while re-solubilization of pre-formed aggregates was not effectively achieved. The same results were obtained using ApoEPLGA. CONCLUSION: An optimized metal chelator nano-formulation with BBB penetrating ability was prepared and presented for further in-vivo studies.

High-performance countercurrent chromatographic isolation of acylated iridoid diglycosides from Verbascum ovalifolium Donn ex Sims and evaluation of their inhibitory potential on IL-8 and TNF-α production.

In traditional folk medicine, Verbascum species have been used since ancient times to treat respiratory disorders, hemorrhoids, diarrhea, wounds, eczema and other types of inflammatory skin conditions. Despite the fact that more than 200 bioactive constituents (phenylethanoids, flavonoids, neolignan glycosides, phenolic acids, iridoids, saponins and polysaccharides) have been previously isolated from various Verbascum species, to date preparative high-performance countercurrent chromatography (HPCCC) has never been employed for this purpose. Therefore, in this study, simple HPCCC methods were successfully developed with the aim to primarily isolate acylated iridoid diglycosides from Verbascum ovalifolium Donn ex Sims (oval-leaved mullein). By the use of several biphasic solvent systems containing n-hexane, ethyl acetate, n-butanol/methanol and water, premnacorymboside B (3, 4 mg, 95.4% purity), saccatoside (4, 6 mg, 95.7% purity), premnacorymboside A (7, 6 mg, 98.3%), scorodioside (8, 11 mg, 96.0%) and 6-O-(3'',4''-di-O-trans-cinnamoyl)-α-L-rhamnopyranosylcatalpol (9, 8 mg, 95.3%) were afforded; compounds 7, 8 and 9 have not been previously reported in Verbascum genus. Additionally, two phenolic acids (1, 2), two flavonoids (6, 10) and verbascoside (5) were secondarily isolated. Evaluation of interleukin 8 (IL-8) and tumor necrosis factor α (TNF-α) inhibitory properties of the acylated iridoid diglycosides proved that these compounds down-regulated TNF-α release more efficiently than IL-8 secretion. The activity might be dependent on the degree of esterification, as diacyl derivatives showed more potent effects than monoesters. The HPCCC methods herein developed could serve to large scale isolation of constituents from Verbascum genus for extensive biological investigations.

Plant-derived verbascoside and isoverbascoside regulate Toll-like receptor 2 and 4-driven neutrophils priming and activation.

BACKGROUND: Neutrophils have a short live in circulation and accelerate greatly local immune responses via increased granulopoiesis and migration at high numbers to infected or inflamed tissue. HYPOTHESIS: Since neutrophils produce a variety of factors with destructive and pro-inflammatory potential the regulation of their homeostasis and functions might be eventually beneficial in inflammation-related pathological conditions. Herein we investigated the effect of natural-derived verbascoside (Verb) and its positional isomer isoverbascoside (IsoVerb) on neutrophil functions. METHODS: We used purified murine bone marrow (BM) neutrophils to study cell responsiveness to priming or activation via Toll-like receptors (TLRs) 2 and 4. The expression of CD11b, chemokine (CXC motif) receptor 2 (CXCR2), the intracellular level of phosphorylated p38 mitogen-activated protein kinase (MAPK) and tumor necrosis factor (TNF)-α in neutrophils were determined by flow cytometry while the release of macrophage inflammatory protein (MIP)-2 in culture supernatant was determined by enzyme-linked immunosorbent assay (ELISA). RESULTS: We found that Verb appeared less powerful inhibitor of TLR2 and TLR4-mediated apoptosis than IsoVerb. However at concentrations below 16 µM and in LPS priming conditions Verb was more selective inhibitor of CD11b and CXCR2 expression than IsoVerb. Both compounds showed similar activity on integrin/chemokine receptor expression when neutrophils were stimulated with ZY or were activated with LPS. Verb sustained CXCR2 expression and turnover via regulation of the cell responsiveness to its ligand KC (CXCL1) and via the release of MIP-2 (CXCL2). Both Verb and IsoVerb increased TNF-α production and inhibited p38 phosphorylation in TNF-α+ cells. We fail to discriminate sharply between Verb's and IsoVerb's efficacy when studying p38 phosphorylation in LPS stimulated neutrophils. The multi-parametric analysis provides critical insight on the range of on-target effects of Verb and IsoVerb. CONCLUSION: The strength and selectivity of Verb and IsoVerb depended on the degree of activation and functional state of neutrophils, and both compounds are with potential to affect neutrophil-related pathologies/conditions in heterogenic populations.

HPLC-DAD-ESI-Q-TOF-MS/MS profiling of Verbascum ovalifolium Donn ex Sims and evaluation of its antioxidant and cytogenotoxic activities.

INTRODUCTION: Plant species of Verbascum genus have been intensively investigated in the last decades but most studies focused on evaluation of their biological activities; there are only few studies dealing with their chemical characterisation. OBJECTIVE: Detailed investigation of the qualitative and quantitative chemical composition, antioxidant and cytogenotoxic activities of a previously non-studied Verbascum species (V. ovalifolium Donn ex Sims). METHODS: Qualitative analysis of secondary metabolites was performed by HPLC-DAD-ESI-Q-TOF-MS/MS, whereas quantitative data were obtained through HPLC-DAD. Antioxidant activity was evaluated using in vitro assays; cytotoxic and genotoxic effects were assessed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium (MTT) and comet assays, respectively. RESULTS: More than 50 secondary bioactive metabolites belonging to various classes (iridoids, phenylethanoids, flavonoids, phenolic acids) were detected in the methanolic extract of V. ovalifolium and its fractions. The fragmentation pathways of acylated catalpol-type iridoid diglycosides are thoughtfully described herein. The extracts showed good free radical scavenging and ferric ion reducing properties correlated with phenolic, flavonoid, chlorogenic acid and verbascoside contents. Moreover, 24 h treatment of SK-MEL-2 cells with V. ovalifolium extracts produced significant changes in terms of tumour cell viability. The crude extract and the ethyl acetate fraction showed no important signs of cytogenotoxicity in non-tumour cells. CONCLUSION: The performed phytochemical and biological analyses contribute to the preclinical knowledge about V. ovalifolium and they could help exploiting it in novel herbal medicinal products.

Factors influencing seedling emergence of three global invaders in greenhouses representing major eco-regions of the world.

Successful germination and seedling emergence in new environments are crucial first steps in the life history of global plant invaders and thus play a key role in processes of range expansion. We examined the germination and seedling emergence success of three global plant invaders - Lupinus polyphyllus, Senecio inaequidens and Verbascum thapsus - in greenhouses and climate chambers under climate regimes corresponding to seven eco-regions. Seed materials were collected from one non-native population for L. polyphyllus and S. inaequidens, and from 12 populations for V. thapsus (six natives and six non-natives). Experimental climates had significant effects on species responses. No species germinated in the dry (humidity ≤ 50%) and cool (≤ 5 °C) experimental climates. But all species germinated and emerged in two moderately cool (12-19 °C) and in three warm (24-27 °C) experimental climates. In general, V. thapsus showed higher fitness than S. inaequidens and L. polyphyllus. The climate of the seed source region influenced responses of native and non-native populations of V. thapsus. Non-native populations of V. thapsus, originating from the warmer seed source, showed higher performance in warm experimental climates and lower performance in moderately cool experimental climates compared to native populations. Responses of V. thapsus populations were also related to precipitation of the seed source region in moderately dry experimental climates. The warm, semi-arid and humid experimental climates are suitable for the crucial first steps of invasion success for L. polyphyllus, S. inaequidens and V. thapsus. The species adaptation to its source region modified the responses of our studied plants under different experimental climates representing major eco-regions of the world.

Antitrypanosomal activity of Verbascum sinaiticum Benth. (Scrophulariaceae) against Trypanosoma congolense isolates.

BACKGROUND: African Trypanosomiasis is a neglected tropical disease with a large impact on the livelihood of the rural poor in Sub-Saharan Africa. The available drugs for managing this disease are old, expensive and are facing the problem of drug resistance. Thus, the aim of this study was to evaluate in vivo antitrypanosomal efficacy of aqueous and absolute methanol leaf extracts of Verbascum sinaiticum Benth. against Trypanosoma congolense field isolate. METHODS: Verbascum sinaiticum (Local name 'qetetina') is a biennial plant, and 60-150 cm tall. It is traditionally used to treat wound, stomachache, viral infection, cancer, sunstroke, fever, abdominal colic, diarrhea, hemorrhage, anthrax, and hepatitis. The efficacy of aqueous and absolute methanol leaf extracts of V. sinaiticum was evaluated in a randomized experiment with Swiss albino mice infected with T. congolense field isolate. The extracts were administered at doses of 100, 200 and 400 mg/kg by intraperitoneal injection for seven days at 12 Days Post-Infection (DPI) when the peak parasitaemia level was approximately 10(8) trypanosomes/ml. Parasitaemia, Packed Cell Volume (PCV), mean survival time and change in body weight were used as indices for monitoring the efficacy of the extracts. Diminazene (28 mg/kg) was used as a positive control while 2 % Tween was used as the negative control. Phytochemicals screening were conducted following standard methods. RESULTS: The extracts showed no toxicity effect in Swiss albino mice and had LD50 above 2000 mg/kg. The phytochemicals screened in V. sinaiticum were alkaloids, flavonoids, glycoside, saponins, steroids, phenolic compounds, and tannins. The mice treated with absolute methanol leaf extract of V. sinaiticum at 400 mg/kg dose had significantly lower mean parasitaemia (7.20 ± 0.16) (p < 0.001) as compared to the negative control group (8.82 ± 0.12) on day 14 of treatment. Animals treated with the same dose had significant (p < 0.001) higher PCV value and body weight and as well as the highest mean survival time of 40.20 ± 0.31 days as compared to the negative control at the end of the observation period. CONCLUSION: This study established that Verbascum sinaiticum had trypanocidal activity. The crude extracts have partially eliminated trypanosomes in a dose-dependent manner. The study can be a basis for future in-depth analysis of the biologically active chemicals.

Effect of Verbascum thapsus ethanol extract on induction of apoptosis in Trichomonas vaginalis in vitro.

Trichomoniasis is a sexually transmitted disease (STD) caused by a tiny parasite called Trichomonas vaginalis. Metronidazole is used as routine treatment of disease. Some reports have confirmed the potential carcinogenic and teratogenic effects of this drug on fetus and indication of drug resistance. Verbascum thapsus belongs to the family of Scorphulariaceae. Its antiinflammatory properties, disinfectant and skin healing effects are well known. This plant has been used to treat diarrhea and genitourinary infection in traditional medicine. Effects of different concentrations of the Verbascum thapsus extract were tested on the growth and motility of T. vaginalis trophozoites. To evaluate the toxicity of extract, their effects on mice macrophages were measured by MTT([3-(4,5-dimethyl thiazolyl-2)- 2,5-diphenyle tetrazolium bromide ])assay. In this experimental study the effect of Verbascum thapsus ethanol extract on induction apoptosis in T. vaginalis was determined by Flow Cytometry. Results were analyzed by Flow Jo software and the degree of apoptosis was determined. Toxicity percentage of 25-800 µg/ml concentrations of Verbascum thapsus alcoholic extract for mice macrophages was observed between 0.17-0.25 after 12 hours and they were between 0.25-0.42 and0.45-0.95 after 24 and 48h respectively. IC50 (inhibitory concentration, 50%) of Verbascum thapsus ethanol extract and metronidazole after 24h was 39.17 and 0.0326 µg/ml respectively. Flow cytometry results showed the percent of apoptosis following treatment of trophozoites with different concentrations of Verbascum thapsus ethanol extract (25, 50,100,200,400 µg/ml), were 20.7, 37.04, 47.5, 62.72 and 86.35 respectively, while in control group was 2.9. According to this study, Verbascum thapsus extract induces programmed death in T. vaginalis. It is recommended that Verbascum thapsus extract can be considered as a suitable choice for Medical Studies.