Chemical Investigation and Antinociceptive Activity Evaluation of Marrubium Vulgare L. Aqueous Extract

Marrubium vulgare L. (Lamiaceae) has a long history of use in traditional herbal medicine for the treatment of respiratory tract infections, inflammatory conditions, and pain. This study aimed to investigate the chemical composition, acute toxicity, and antinociceptive effects of the aqueous extract from M. vulgare leaves (AEMV). Antioxidant activity was evaluated using DPPH and reducing power assays. The chemical composition of AEMV was determined through LC-MS/MS, and the levels of total phenolics, flavonoids, and condensed tannins were quantified. Acute oral toxicity was assessed in male Swiss mice with a single oral dose of AEMV (1, 2, 5 g/kg). The analgesic impact was examined through writhing, hot plate, and formalin tests. Our findings not only confirmed the safety of the extract in animal models but also revealed significant antioxidant activity in AEMV. High-performance liquid chromatography (HPLC) analysis identified important bioactive compounds, with marrubiin being a major component. Furthermore, AEMV demonstrated robust antinociceptive properties in all conducted tests, highlighting its potential as a valuable natural source of bioactive compounds suitable for a wide range of therapeutic applications.

Marrubium vulgare Extract Improves Spatial Working Memory and Oxidative Stress Damage in Scopolamine-Treated Rats

Background

The cholinergic neuronal loss in the basal forebrain and increasing brain oxidative stress are one of the main features of the brain suffering from Alzheimer's disease. Marrubium vulgare (M. vulgare), commonly known as 'white horehound,' possesses a variety of valuable properties, such as antioxidative, anti-inflammatory, and antidiabetic activities. Moreover, it possesses neuromodulatory properties that could potentially impact short-term memory functions.

Objective

The present study was undertaken to investigate the preventive effects of water M. vulgare extract on working memory, cholinergic neurotransmission, and oxidative stress in rats with scopolamine (Sco)-induced dementia.

Methods

Male Wistar rats (200-250 g) were divided into four experimental groups. The plant extract was administered orally for 21 days, and Sco (2 mg/kg) was administered intraperitoneally for 11 consecutive days. The behavioral performance of the animals was evaluated by the T-maze test. The effect of the extract on acetylcholinesterase (AChE) activity and antioxidant status in cortex and hippocampus were also monitored.

Results

Our experimental data revealed that treatment with M. vulgare significantly increased the percentage of correct choices of rats with Sco-induced dementia in the T maze test (by 38%, p < 0.05). Additionally, it reduced AChE activity in the hippocampus (by 20%, p < 0.05) and alleviated oxidative stress induced by Sco, particularly in the cortex.

Conclusions

M. vulgare water extract demonstrated working memory preserving effect in rats with Sco-induced dementia, AChE inhibitory activity and in vivo antioxidant potential, and deserve further attention.

Metabolome Profiling of Marrubium peregrinum L. and Marrubium friwaldskyanum Boiss Reveals Their Potential as Sources of Plant-Based Pharmaceuticals

Marrubium species have been used since ancient times as food additives and curative treatments. Their phytochemical composition and various pharmacological activities were the focus of a number of scientific investigations but no comprehensive metabolome profiling to identify the numerous primary and secondary metabolites has been performed so far. This study aimed to generate a comprehensive picture of the total metabolite content of two Marrubium species-M. peregrinum and M. friwaldskyanum-to provide detailed information about the main primary and secondary metabolites. In addition, the elemental composition was also evaluated. For this purpose, non-targeted metabolomic analyses were conducted using GC-MS, UPLC-MS/MS and ICP-MS approaches. Nearly 500 compounds and 12 elements were detected and described. The results showed a strong presence of phenolic acids, flavonoids and their glucosides, which are generally of great interest due to their various pharmacological activities. Furthermore, tissue-specific analyses for M. friwaldskyanum stem, leaves and flowers were carried out in order to outline the sources of potentially important bioactive molecules. The results generated from this study depict the Marrubium metabolome and reveal its dual scientific importance-from one side, providing information about the metabolites that is fundamental and vital for the survival of these species, and from the other side, defining the large diversity of secondary substances that are a potential source of phytotherapeutic agents.

Chemical diversity analysis and biological activities evaluation of different polyphenolic extracts of Marrubium deserti De Noé from Algeria

ETHNOPHARMACOLOGICAL RELEVANCE

Marrubium deserti De Noé (Lamiaceae) commonly known as desert horehound, is a small perennial herb distributed in arid climates. This plant has been used in Algeria for the treatment of cold, cough, fever and inflammation.

AIM OF THE STUDY

This study aimed to perform a phytochemical analysis and to evaluate the effect of diethyl ether (ExDiEth), n-butanol (ExBut) and hydroalcoholic (ExHyD) extracts of the aerial parts of M. deserti De Noé on inflammation, nociceptive response and fever in animal models.

MATERIALS AND METHODS

The total phenolic content and the different phenolic fraction (flavones-flavonols, free aglycones, anthocyanidins, C-glycosides and flavonic heterosides) were quantified in order to study the chemical diversity. The anti-inflammatory effect was evaluated using carrageenan-induced paw oedema test and the nociceptive response was determined by the chemical method using acetic acid-induced writhing response and formalin-induced paw licking tests and by the thermal method using the hot plate in mice. In addition, anti-fever was investigated using yeast-induced pyrexia in rats.

RESULTS

Quantitative analysis revealed that among all extracts, ExBut had a higher phenolic content and the aerial parts of M. deserti De Noé collected from two different sites (Biskra and Tamanresset) had a significant difference in the contents of flavonic heterosids and flavones-flavonols. PCA and CA showed a strong intra-specific variability of M. deserti De Noé individuals. Our results showed that the ExDiEth, ExBut and ExHyD treatments prevented the increase of paw oedema by 56.25%, 66.65% and 45.56% inhibition percent, respectively. Moreover, treatments with these extracts significantly (p<0.05) decreased the number of writhing and increased the reaction time to thermal stimulation as well as demonstrated reduction in paw licking time both at early and late phases. Likewise, they also showed a significant reduction of yeast-induced pyrexia till 4 h of treatment.

CONCLUSION

Results from this study show that M. deserti De Noé aerial parts exhibited anti-inflammatory, analgesic with central and peripheral actions and antipyretic activities which could be associated with the presence of some phytochemicals as flavones, flavonols, flavonic heterosids and phenolic acids.

In Vitro and In Vivo Studies of Metabolic Activation of Marrubiin, a Bioactive Constituent from Marrubium Vulgare

Marrubiin, a furanoid compound, is a well-known diterpenoid lactone isolated from Marrubium vulgare, which displays a wide spectrum of pharmacological effects and potential hepatotoxicity. Considering that marrubiin contains a structural alert, furan ring, metabolic activation may be one of the major metabolic pathways, and the reactive metabolite may be involved in the hepatotoxicity. The present study was carried out to investigate the bioactivation mechanism of marrubiin in rats and humans. Marrubiin was initially metabolized into cis-butene-1,4-dial intermediate, which was readily trapped by glutathione (GSH) and N-acetyl-lysine (NAL) in the microsomal incubations supplemented with NADPH. A total of nine conjugates were detected and identified by high-resolution mass spectrometry and nuclear magnetic resonance (NMR) spectroscopy. M1-M3 and M6 and M7 were characterized as mono-GSH conjugates, and M4 and M5 were identified as bis-GSH conjugates. M8 and M9 were identified as NAL conjugates. In rat bile, five GSH conjugates (M1-M3; M6 and M7) were detected. M1, M8, and M9 were chemically synthesized, and their structures were characterized by 13C NMR. Sulfaphenazole, ticlopidine, and ketoconazole displayed significant inhibitory effect on the bioactivation of marrubiin. Further phenotyping revealed that CYP2C9, CYP2C19, and CYP3A4 were the primary enzymes catalyzing the bioactivation of marrubiin. The current study provides evidence for the CYP-dominated bioactivation of marrubiin to the corresponding cis-butene-1,4-dial intermediate, which enables us to better understand the potential side effects caused by marrubiin.

HPLC-Analysis, Biological Activities and Characterization of Action Mode of Saudi Marrubium vulgare against Foodborne Diseases Bacteria

The present study aims to evaluate the chemical composition, metabolites secondary and pharmacology activities of methanolic extract of Marrubium vulgare collected from King Saudi Arabia. Moreover, the primary mode of action of the tested extract was studied here for the first time against E. coli and L. monocytogenes. HPLC analysis shows that the major components in the tested extract are luteolin-7-O-d-glucoside, ferulic acid and premarrubiin. Obtained data demonstrated that the investigated extract was richer in phenol (26.8 ± 0.01 mg/GAE g) than in flavonoids (0.61 ± 0.05 mg EC/mL). In addition, the methanolic extract showed an important antioxidant capacity against the DPPH (IC₅₀ = 35 ± 0.01 µg/mL) and ABTS (IC₅₀ = 25 ± 0.2 µg/mL) radical scavenging and a strong inhibition of acetylcholinesterase enzyme with an IC₅₀ value corresponding to 0.4 mg/mL. The antibacterial activity demonstrated that the evaluated extract had significant activity against both Gram-positive and Gram-negative bacteria. The effect of time on cell integrity on E. coli and L. monocytogenes determined by time-kill and bacteriolysis tests showed that the M. vulgare extract reduced the viability of both strains after 8 and 10 h and had a bacteriolytic effect against two different categories of bacteria, Gram-positive and negative, which are not of the same potency. Based on obtained data, it can be concluded that Saudi M. vulgare has a high pharmacological importance and can be used in preparation of food or drugs.

Phytochemical Analysis and Trypanocidal Activity of Marrubium incanum Desr

The rationale inspiring the discovery of lead compounds for the treatment of human parasitic protozoan diseases from natural sources is the well-established use of medicinal plants in various systems of traditional medicine. On this basis, we decided to select an overlooked medicinal plant growing in central Italy, Marrubium incanum Desr. (Lamiaceae), which has been used as a traditional remedy against protozoan diseases, and to investigate its potential against Human African trypanosomiasis (HAT). For this purpose, we assayed three extracts of different polarities obtained from the aerial parts of M. incanum—namely, water (MarrInc-H₂O), ethanol (MarrInc-EtOH) and dichloromethane (MarrInc-CH₂Cl₂)—against Trypanosoma brucei (TC221), with the aim to discover lead compounds for the development of antitrypanosomal drugs. Their selectivity index (SI) was determined on mammalian cells (BALB/3T3 mouse fibroblasts) as a counter-screen for toxicity. The preliminary screening selected the MarrInc-CH₂Cl₂ extract as the most promising candidate against HAT, showing an IC₅₀ value of 28 μg/mL. On this basis, column chromatography coupled with the NMR spectroscopy of a MarrInc-CH₂Cl₂ extract led to the isolation and identification of five compounds i.e. 1-α-linolenoyl-2-palmitoyl-3-stearoyl-sn- glycerol (1), 1-linoleoyl-2-palmitoyl-3-stearoyl-sn-glycerol (2), stigmasterol (3), palmitic acid (4), and salvigenin (5). Notably, compounds 3 and 5 were tested on T. brucei, with the latter being five-fold more active than the MarrInc-CH₂Cl₂ extract (IC₅₀ = 5.41 ± 0.85 and 28 ± 1.4 μg/mL, respectively). Furthermore, the SI for salvigenin was >18.5, showing a preferential effect on target cells compared with the dichloromethane extract (>3.6). Conversely, stigmasterol was found to be inactive. To complete the work, also the more polar MarrInc-EtOH extract was analyzed, giving evidence for the presence of 2″-O-allopyranosyl-cosmosiin (6), verbascoside (7), and samioside (8). Our findings shed light on the phytochemistry of this overlooked species and its antiprotozoal potential, providing evidence for the promising role of flavonoids such as salvigenin for the treatment of protozoal diseases.

Marrubium vulgare L.: A Phytochemical and Pharmacological Overview

Marrubium vulgare is a plant with high bioactive potential. It contains marrubiin, a labdane diterpene that is characteristic for this genus, as well as a complex mixture of phenolic compounds. According to numerous studies, M. vulgare acts as a good antioxidant agent, and due to this, it could potentially be useful in treatments of cancer, diabetes mellitus, and liver diseases. In addition, its anti-inflammatory, wound-healing, antihypertensive, hypolipidemic, and sedative potential are discussed. Apart from that, its antimicrobial activity, especially against Gram+ bacteria, fungi, herpes simplex virus, and parasites such as Toxoplasma gondii, Trichomonas vaginalis, and Plasmodium berghei-berghei was recorded. Additionally, it could be used as a chicken lice repellent, herbicide, and natural insecticide against mosquito larvae and natural molluscicide. In veterinary medicine, M. vulgare can be used as an anthelmintic against the eggs and larvae of bovine strongyles parasites, and as an antibiotic against bovine mastitis caused by resistant bacterial strains. Due to the mentioned benefits, there is a tendency for the cultivation of M. vulgare in order to ensure high-quality raw material, but more firm scientific evidence and well-designed clinical trials are necessary for the well-established use of M. vulgare herb and its preparations.

The use of a microwave-assisted solvent extraction coupled with HPLC-UV/PAD to assess the quality of Marrubium vulgare L. (white horehound) herbal raw material

INTRODUCTION

Marrubium vulgare is a herbal remedy presents in several European Pharmacopoeias and commonly marketed as white horehound. The chemotaxonomic marker of Marrubium genus is marrubiin and its content may change in response to biotic and abiotic stress.

OBJECTIVE

Development of a microwave-assisted solvent extraction (MASE) methodology suitable for exhaustively extracting marrubiin from M. vulgare leaves, easily applicable to large sets of samples. Evaluation of the influence of copper(II) on marrubiin production.

MATERIAL AND METHODS

M. vulgare leaves were dried, extracted exploiting MASE and analysed via high-performance liquid chromatography ultraviolet photodiode array detection (HPLC-UV/PAD) system. A design of experiments approach was adopted to select the best extraction conditions. Extraction parameters (solvent composition, extraction time and temperature), were studied applying two full factorial experimental designs in a sequential approach. To analyse samples, a rapid HPLC-UV/PAD method was set up.

RESULTS

The best results in terms of marrubiin extraction yield were obtained extracting samples at 120°C with 100% ethanol, for 15 min (3 × 5 min microwave cycles). The developed methodology was successfully applied to matrices grown in Greenhouse conditions and under stress induced by copper(II), selected as model agent for abiotic stress. Progressively decreasing production of marrubiin was evidenced in connection with treatment with 80, 200 and 300 mg/L copper sulphate.

CONCLUSION

An efficient methodology for the extraction and determination of the amount of marrubiin in large sets of samples of M. vulgare plants was developed. Results demonstrated that marrubiin is an easily detectable marker useful for evaluating M. vulgare reaction to stress.

Marrubium vulgare ethanolic extract induces proliferation block, apoptosis, and cytoprotective autophagy in cancer cells in vitro

Marrubium vulgare is a European medicinal plant with numerous beneficial effects on human health. The aim of the study was to isolate the plant ethanolic extract (MVE) and to investigate its anti-melanoma and anti-glioma effects. MVE was prepared by the modified pharmacopoeial percolation method and characterized by UHPLC-LTQ OrbiTrap MS. MVE dose-dependently reduced viability of melanoma (B16) and glioma (U251) cells, but not peripheral blood mononuclear cells. It arrested cell cycle in S+G2/M phase, which was associated with the activation of MAP kinase p38 and up-regulation of antiproliferative genes p53, p21 and p27. MVE induced oxidative stress, while antioxidants abrogated its antitumor effect. Furthermore, MVE induced mitochondrial depolarization, activation of caspase-9 and -3, Parp cleavage, phosphatidylserine exposure and DNA fragmentation. The mitochondrial apoptotic pathway was associated with the up-regulation of proapoptotic genes Pten, Bak1, Apaf1, and Puma and down-regulation of antiapoptotic genes survivin and Xiap. MVE also stimulated the expression of autophagy-related genes Atg5, Atg7, Atg12, Beclin-1, Gabarab and Sqstm1, as well as LC3-I conversion to the autophagosome associated LC3-II, while autophagy inhibitors exacerbated its cytotoxicity. Finally, the most abundant phenolic components of MVE, ferulic, p-hydroxybenzoic, caffeic and chlorogenic acids, did not exert a profound effect on viability of tumor cells, suggesting that other components individually or in concert are the mediators of the extracts' cytotoxicity. By demonstrating the ability of MVE to inhibit proliferation, induce apoptosis and cytoprotective autophagy, our results suggest that MVE, alone or combined with autophagy inhibitors, could be a good candidate for anti-melanoma and anti-glioma therapy.

Diterpene synthases of the biosynthetic system of medicinally active diterpenoids in Marrubium vulgare

Marrubium vulgare (Lamiaceae) is a medicinal plant whose major bioactive compounds, marrubiin and other labdane-related furanoid diterpenoids, have potential applications as anti-diabetics, analgesics or vasorelaxants. Metabolite and transcriptome profiling of M. vulgare leaves identified five different candidate diterpene synthases (diTPSs) of the TPS-c and TPS-e/f clades. We describe the in vitro and in vivo functional characterization of the M. vulgare diTPS family. In addition to MvEKS ent-kaurene synthase of general metabolism, we identified three diTPSs of specialized metabolism: MvCPS3 (+)-copalyl diphosphate synthase, and the functional diTPS pair MvCPS1 and MvELS. In a sequential reaction, MvCPS1 and MvELS produce a unique oxygenated diterpene scaffold 9,13-epoxy-labd-14-ene en route to marrubiin and an array of related compounds. In contrast with previously known diTPSs that introduce a hydroxyl group at carbon C-8 of the labdane backbone, the MvCPS1-catalyzed reaction proceeds via oxygenation of an intermediate carbocation at C-9, yielding the bicyclic peregrinol diphosphate. MvELS belongs to a subgroup of the diTPS TPS-e/f clade with unusual βα-domain architecture. MvELS is active in vitro and in vivo with three different prenyl diphosphate substrates forming the marrubiin precursor 9,13-epoxy-labd-14-ene, as identified by nuclear magnetic resonance (NMR) analysis, manoyl oxide and miltiradiene. MvELS fills a central position in the biosynthetic system that forms the foundation for the diverse repertoire of Marrubium diterpenoids. Co-expression of MvCPS1 and MvELS in engineered E. coli and Nicotiana benthamiana offers opportunities for producing precursors for an array of biologically active diterpenoids.

Chemical constituents of Marrubium vulgare as potential inhibitors of nitric oxide and respiratory burst

Phytochemical investigation of the whole plant of Marrubium vulgare L., led to the isolation of three new secondary metabolites, 11-oxomarrubiin (1), vulgarcoside A (2) and 3-hydroxyapigenin-4'-O-(6"-O-p-coumaroyl)-beta-D-glucopyranoside (3), along with four known constituents 4-7 from the polar fractions of the methanolic extract. The structures of all compounds were deduced on the basis of NMR data and HRESI-MS measurements. The new constituents 1-3 exhibited moderate to low level of inhibition on nitric oxide (NO.) production. The compound 2 also showed a moderate inhibition on pro-inflammatory cytokine TNF-alpha. The new constituents 1-3 showed no inhibitory effect on Reactive Oxygen Species (ROS) production.

Cardioprotective effect of methanolic extract of Marrubium vulgare L. on isoproterenol-induced acute myocardial infarction in rats

Isoproterenol injection (100 mg/kg; sc) produced changes in ECG pattern including ST-segment elevation and suppressed R-amplitude. The methanolic extract of M. vulgare at doses of 10, 20, and 40 mg/kg significantly amended the ECG changes. A severe myocardial necrosis and edematous along with a sharp reduction in the arterial blood pressure, left ventricular contractility (LVdP/dt(max or min)), but a marked increase in the left ventricular end-diastolic pressure (LVEDP) were seen in the isoproterenol group. All parameters were significantly improved by the extract treatment. The extract (10 mg/kg) strongly increased LVdP/dt(max). Similarly, treatment with 40 mg/kg of M. vulgare lowered the elevated LVEDP and the heart to body weight ratio. In addition to in vitro antioxidant activity, the extract suppressed markedly the elevation of malondialdehyde levels both in serum and in myocardium. The results demonstrate that M. vulgare protects myocardium against isoproterenol-induced acute myocardial infarction and suggest that the effects could be related to antioxidant activities.

Ethnobotany of medicinal plants used in Xalpatlahuac, Guerrero, México

ETHNOPHARMACOLOGICAL IMPORTANCE

Medicinal plants have been used for centuries for the empirical treatment of many diseases. This study documented the use of plant species in traditional medicine in the municipality of Xalpatlahuac, Guerrero, México.

MATERIALS AND METHODS

Direct interviews were performed with inhabitants from Xalpatlahuac. The interviews were analyzed with two quantitative tools: (a) the informant consensus factor (ICF) that estimates the level of agreement about which medicinal plants may be used for each category and (b) the relative importance (RI) that determines the extent of potential utilization of each species.

RESULTS

A total of 67 plant species with medicinal purposes, belonging to 36 families and used to treat 55 illnesses and 3 cultural filiations were reported by interviewees. Nineteen mixtures with medicinal plants were reported by the interviewers. Mentha piperita was the most used plant for combinations (4 mixtures). The results of the ICF showed that diseases of the respiratory and digestive systems had the greatest agreement. The most versatile species according to their RI are Marrubium vulgare, Mimosa albida and Psidium guajava..

CONCLUSION

This study demonstrates that plant species play an important role in healing practices and magical-religious rituals among inhabitants from Xalpatlahuac, Guerrero, Mexico. Furthermore, pharmacological, phytochemical and toxicological studies with medicinal flora, including mixtures, are required for the experimental validation of their traditional uses.

Activity of ladanein on leukemia cell lines and its occurrence in Marrubium vulgare

Three methoxylated flavones isolated from Marrubium peregrinum - ladanein, scutellarein-5,7,4'-trimethyl ether, and scutellarein-5,6,7,4'-tetramethyl ether - were assayed for their cytotoxicity towards a recently developed dasatinib-resistant murine leukemia cell line (DA1-3b/M2 (BCR-ABL)), together with the structurally related non-methylated flavone scutellarein. The most active compound, ladanein, was looked for in 20 common Lamiaceae species by a quick HPLC screening. Among the possible positive results, the most interesting source was found to be Marrubium vulgare, which led to the isolation and identification of ladanein for the first time in this species. Ladanein also displayed moderate (20-40 microM) activities against K562, K562R (imatinib-resistant), and 697 human leukemia cell lines but was toxic neither to MOLM13 nor to human peripheral blood mononuclear cells. This work provides a common natural source for the hemi-synthesis of future ladanein-derived flavones and the study of their antileukemic activity.

Antispasmodic effects and structure-activity relationships of labdane diterpenoids from Marrubium globosum ssp. libanoticum

Marrubium globosum ssp. libanoticum is a medicinal plant used in Lebanon to reduce pain and smooth muscle spasms. A chloroform extract obtained from M. globosum aerial parts reduced acetylcholine-induced contractions in the isolated mouse ileum. The purification of this extract identified, among 12 isolated labdane diterpenoids, four new compounds, named 13-epicyllenin A (4), 13,15-diepicyllenin A (5), marrulibacetal (9), and marrulactone (11). Their structures were determined by spectroscopic methods. Compound 9, which exerted antispasmodic activity, is likely the active ingredient of the extract. Preliminary structure-activity relationships for this class of compounds are suggested.

Composition, antioxidant and antimicrobial activities of the essential oil of Marrubium deserti

The essential oil from aerial part of Marrubium deserti De Noé (Lamiaceae), obtained by hydrodistillation was analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS), and evaluated for in vitro antimicrobial activity. The antioxidant activity was determined using three in vitro assays: scavenging effect on DPPH, the ABTS test and the phosphomolybdenum method. Thirty-seven compounds were identified in the oil, with germacrene D as the major component (45.7%). This oil was characterized by an important hydrocarbon fraction (78.1%) and by the predominance of sesquiterpenes (67.4%). M. deserti essential oil had no activity on the tested microorganisms (Staphylococcus aureus ATCC 25923, Echerichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Candida albicans and Aspergillus flavus). However the oil presented an antioxidant activity.

Labdane diterpenes from Marrubium thessalum

From the aerial parts of Marrubium thessalum, four labdane diterpenes, 13S-preperegrinine, 3alpha-hydroxymarrubiin, 9alpha,13R-15,16-bisepoxy-15beta-methoxy-3-oxo-labdan-6beta,19-olide and 15-methoxyvelutine C, have been isolated together with four known diterpenes and one methoxylated flavone, ladanein. The structures of the isolated compounds were established by means of NMR (COSY, HSQC, HMBC, NOESY, and ROESY) and MS spectral analyses. Complete NMR assignments are reported for 13R-preperegrinine. Characteristic compounds of the plant were peregrinine and ladanein.

Composition and antimicrobial activity of Marrubium incanum Desr. (Lamiaceae) essential oil

The essential oil from the aerial parts of Marrubium incanum Desr. (Lamiaceae), obtained by hydrodistillation, was analyzed by GC and GC-MS. Forty-six compounds were identified, representing 96.3% of the total oil. The main components of the oil were (E)-caryophyllene (27.0%), germacrene D (26.2%) and bicyclogermacrene (11.5%). The microbial growth inhibitory properties of the isolated essential oil were determined using the agar diffusion and broth microdilution method against seven bacterial species (Staphylococcus aureus ATCC 25923, S. epidermidis ATCC 12228, Micrococcus flavus ATCC 10240, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, Klebsiella pneumoniae NCIMB 9111, and Pseudomonas aeruginosa ATCC 27853), and two strains of the yeast Candida albicans (ATCC 10259 and ATCC24433). The essential oil showed activity against all the microorganisms tested, but differences in microbial susceptibility were registered.

Antibacterial activity of flavonoids and phenylpropanoids from Marrubium globosum ssp. libanoticum

Marrubium globosum Montbr. et Auch. ex Benth. ssp. libanoticum Boiss. (Lamiaceae) is a medicinal plant used for the treatment of inflammatory diseases, asthma, coughs and other pulmonary and urinary problems. The goal of our study was to assess the biological activity of M. globosum testing the methanol extract of aerial parts for its antibacterial activity against bacteria known to cause respiratory, gastrointestinal, skin and urinary disorders; the extract showed antibacterial effects against all the strains of bacteria used. A purification of this active extract showed the presence, as main constituents, of verbascoside, isorhamnetin 3-O-beta-D-rutinoside, quercetin 3-O-beta-D-rutinoside, naringenin 7-O-beta-D-glucoside, kaempferol 3-O-beta-D-rutinoside, isorhamnetin 3-O-beta-D-glucoside, quercetin 3-O-beta-D-glucoside, apigenin 7-O-(3''-p-coumaryl)-glucoside, p-methoxy-cinnamic acid, kaempferol 3-O-beta-D-glucoside and apigenin 7-O-beta-D-glucoside. The pure compounds were tested for their antibacterial activity; quercetin 3-O-beta-D-rutinoside, verbascoside and naringenin 7-O-beta-D-glucoside showed the greatest activity.

Cytotoxicity and immunomodulating characteristics of labdane diterpenes from Marrubium cylleneum and Marrubium velutinum

From the aerial parts of Marrubium cylleneum, one labdane nor-diterpene has been isolated together with two labdane diterpenes, hitherto not known as natural products. The structures of the isolated compounds were established by means of NMR [(1)H-(1)H-COSY, (1)H-(13)C-HSQC, HMQC-TOCSY, HMBC, NOESY] and MS spectral analyses. Several diterpenoids from M. cylleneum and M. velutinum were tested for their cytotoxic effect against various cancer cell lines and their immunomodulating potential in human peripheral blood mononuclear cells in standard in vitro assays. Our results show a differential cytotoxicity of some compounds as well as their ability to improve selected lymphocyte functions.

Antimicrobial and cytotoxic activity of Marrubium alysson and Retama raetam grown in Tunisia

Antibacterial and antifungal activities of extracts obtained from M. alysson, R. raetam were tested using a solid medium technique. We showed that the petroleum ether extract of M. alysson had a Minimum Inhibitory Concentration (MIC) varied from 128 to 2000 microg mL(-1) against different Enterobacteriaceae and antifungal activity against Candida glabrata, Candida albicans, Candida parapsilosis and Candida kreusei with a MIC of 256 microg mL(-1). The ethyl acetate extract of R. raetam showed the best activity against Gram positive organisms with MICs of 128 to 256 microg mL(-1) against methicillin resistant Staphylococcus aureus but low activity against the different Candida species.

Identification of tyrosinase inhibitors from Marrubium velutinum and Marrubium cylleneum

Tyrosinase is a key enzyme in the production of melanins in plants and animals. Forty-five secondary metabolites isolated from Marrubium velutinum and Marrubium cylleneum belonging to the classes of flavonoids, phenylethanoid glycosides, phenolic acids and lignan glycosides were screened for their inhibitory activity against mushroom tyrosinase. Flavonoids and phenylethanoid glycosides showed moderate inhibitory activity, while phenolic acids were less active than phenylethanoid glycosides, suggesting that both phenolic groups are important for the activity.

Antioedematogenic effect of marrubiin obtained from Marrubium vulgare

This paper describes the antioedematogenic profile of marrubiin (1), the main constituent of Marrubium vulgare, a medicinal plant used in folk medicine of several countries to treat different pathologies. Compound (1) was analyzed in a model of microvascular leakage in mice ears. The results show that it exhibits significant and dose-related antioedematogenic effects. The results obtained for ID50 values (mg/kg, i.p.) and maximal inhibition (%) for the different phlogistic agents used were as follows: histamine (HIS, 13.84 mg/kg and 73.7%); (BK, 18.82 mg/kg and 70.0%); carrageenan (CAR, 13.61 mg/kg and 63.0%). The other phlogistic agonists, such as prostaglandin E2 (PGE2), caused inhibition of less than 50%. In addition, (1) (100 mg/kg) significantly inhibited the OVO-induced allergic edema in actively sensitized animals (maximal inhibition 67.6+/-4%). Our results demonstrate that the systemic administration of marrubiin exerts a non-specific inhibitory effect on pro-inflammatory agent-induced microvascular extravasation of Evans blue in mouse ear.

Marrubium vulgare extract inhibits human-LDL oxidation and enhances HDL-mediated cholesterol efflux in THP-1 macrophage

The objective of the present study was to elucidate the beneficial properties of aqueous extracts of Marrubium vulgare (AEM) towards cardiovascular disease by protecting human-LDL against lipid peroxidation and promoting HDL-mediated cholesterol efflux. Human-LDL were oxidised by incubation with CuSO(4) in the presence of increased concentrations of AEM (0-100 microg/ml). LDL lipid peroxidation was evaluated by conjugated diene formation, vitamin E disappearance as well as LDL-electrophoretic mobility. HDL-mediated cholesterol efflux assay was carried out in human THP-1 macrophages. Incubation of LDL with AEM significantly prolonged the lag phase (P=0.014), lowered the progression rate of lipid peroxidation (P=0.004), reduced the disappearance of vitamin E and the electrophoretic mobility in a dose-dependent manner. Also, incubation of HDL with AEM significantly increased HDL-mediated cholesterol efflux from THP-1 macrophages implicating an independent ATP binding cassette A1 (ABCA1) pathways. Our findings suggest that M. vulgare provides a source of natural antioxidants, which inhibit LDL oxidation and enhance reverse cholesterol transport and thus can prevent cardiovascular diseases development. These antioxidant properties increase the anti-atherogenic potential of HDL.

Labdane Diterpenoids from Marrubium globosum ssp. libanoticum

From the aerial parts of Marrubium globosum ssp. libanoticum, seven labdane diterpenoids were isolated. Three of them are new natural products [(13R)-9alpha,13alpha-epoxylabda-6beta(19),16(15)-diol dilactone (2), deacetylvitexilactone (7), marrulanic acid (8)], whereas the other four, namely, (13S)-9alpha,13alpha-epoxylabda-6beta(19),16(15)-diol dilactone (1), cyllenin A (3), 15-epi-cyllenin A (4), and marrulibanoside, are previously known compounds. The structures of 2, 7, and 8 were determined by spectroscopic and chemical methods.

Labdane diterpenes from Marrubium velutinum and Marrubium cylleneum

From the aerial parts of Marrubium velutinum and Marrubium cylleneum, seven labdane diterpenes, velutine A, 15-epi-velutine A, velutine B, 15-epi-velutine B, velutine C, cyllenine A and 15-epi-cyllenine A, have been isolated together with five known diterpenes and four known flavones. The structures of the isolated compounds were established by means of NMR [(1)H-(1)H-COSY, (1)H-(13)C-HMQC, HMBC, HMQC-TOCSY, NOESY] and MS spectral analyses. Complete NMR assignments are reported for known compounds.

Analgesic potential of marrubiin derivatives, a bioactive diterpene present in Marrubium vulgare (Lamiaceae)

Marrubiin, a furane labdane diterpene, is the main analgesic compound present in Marrubium vulgare, a medicinal plant used in Brazil and other countries to treat several ailments. Considering its important pharmacological action, as well as its high yield, some structural modifications were performed in order to obtain more active compounds. Success was obtained in reducing the lactonic function, in the formation of marrubiinic acid and two esterified derivatives, which exhibited significant analgesic effect against the writhing test in mice. Marrubiinic acid showed better activity and excellent yield, and its analgesic effect was confirmed in other experimental models of pain in mice, suggesting its possible use as a model to obtain new and potent analgesic agents.

Clinical trial of Cecropia obtusifolia and Marrubium vulgare leaf extracts on blood glucose and serum lipids in type 2 diabetics

Cecropia obtusifolia and Marrubium vulgare have been widely used in Mexican traditional medicine for the control of type 2 diabetes. In order to evaluate the clinical effect produced by the aqueous extract from these species on type 2 non-controlled diabetes mellitus, a total of 43 outpatients were included. Based on the European NIDDM (policy group) criteria, only patients with poor response to the conventional treatment were selected. All patients maintained their medical treatment and also received a prepared infusion of the dry leaves of the plant treatment for 21 days. In a double-blind manner, the patients were randomly grouped as follows: 22 patients were treated with C. obtusifolia and 21 with M. vulgare. The fasting blood glucose values were reduced by 15.25% on patients treated with C. obtusifolia, while cholesterol and triglycerides were decreased by 14.62% and 42.0%, respectively (ANOVA p< 0.02). In the case of patients treated with M. vulgare, the plasma glucose level was reduced by 0.64% and cholesterol and triglycerides by 4.16% and 5.78%, respectively. When the results were compared between groups, significant differences in glucose and cholesterol diminution were found. The obtained results showed that the infusion prepared with the leaves of C. obtusifolia (containing 2.99+/-0.14mg of chlorogenic acid/g of dried plant) produced beneficial effects on carbohydrate and lipid metabolisms when it was administered as an adjunct on patients with type 2 diabetes with poor response to conventional medical treatment.

Characterisation of marrubenol, a diterpene extracted from Marrubium vulgare, as an L-type calcium channel blocker

1. The objective of the present study was to investigate the mechanism of the relaxant activity of marrubenol, a diterpenoid extracted from Marrubium vulgare. In rat aorta, marrubenol was a more potent inhibitor of the contraction evoked by 100 mM KCl (IC50: 11.8+/-0.3 microM, maximum relaxation: 93+/-0.6%) than of the contraction evoked by noradrenaline (maximum relaxation: 30+/-1.5%). 2. In fura-2-loaded aorta, marrubenol simultaneously inhibited the Ca2+ signal and the contraction evoked by 100 mM KCl, and decreased the quenching rate of fura-2 fluorescence by Mn2+. 3. Patch-clamp data obtained in aortic smooth muscle cells (A7r5) indicated that marrubenol inhibited Ba2+ inward current in a voltage-dependent manner (KD: 8+/-2 and 40+/-6 microM at holding potentials of -50 and -100 mV, respectively). 4. These results showed that marrubenol inhibits smooth muscle contraction by blocking L-type calcium channels.

Acylated flavonoid and phenylethanoid glycosides from Marrubium velutinum

From the aerial parts of Marrubium velutinum, one acylated flavonoid glycoside, chrysoeriol 7-O-(3",6"-di-O-E-p-coumaroyl)-beta-D-glucopyranoside, and two tetrasaccharidic phenylethanoid glycosides, velutinosides I-II, have been isolated together with ten known flavonoids and seven known phenylethanoid glycosides. The structures of the isolated compounds were established by means of NMR, MS, and UV spectral analyses.

The vasorelaxant activity of marrubenol and marrubiin from Marrubium vulgare

Crude extracts of the aerial parts of Marrubium vulgare show a potent in vitro inhibition of KCl-induced contraction of rat aorta. Bio-guided fractionations, spectroscopic analysis and chemical derivatization revealed the furanic labdane diterpenes marrubenol and marrubiin as the most active compounds.

Marruboside, a new phenylethanoid glycoside from Marrubium vulgare L

A new phenylethanoid glycoside, marruboside, has been isolated from the aerial parts of Marrubium vulgare L. Its structure was established as 3,4-dihydroxy-beta-phenylethoxy-O-[beta-D-apiofuranosyl-(1-->2)-alpha-L-rhamnopyranosyl-(1-->3)]-[beta-D-apiofuranosyl-(1-->6)]-4-O-caffeoyl-beta-D-glucopyranoside, on the basis of spectroscopic evidence.

Isolation and pharmacological activity of phenylpropanoid esters from Marrubium vulgare

The isolation and identification of major phenylpropanoid esters from Marrubium vulgare: (+) (E)-caffeoyl-L-malic acid 1, acteoside 2, forsythoside B 3, arenarioside 4, ballotetroside 5, as well as their anti-inflammatory activity are reported for the first time. We evaluated the inhibitory effects of these five compounds on cyclooxygenase (Cox) catalysed prostaglandin biosynthesis activity. Only the glycosidic phenylpropanoid esters showed an inhibitory activity towards the Cox-2 enzyme and three of them: acteoside 2, forsythoside B 3, arenarioside 4, exhibited higher inhibitory potencies on Cox-2 than on Cox-1. These results are of interest, as Cox-2 is mainly associated with inflammation and the Cox-1 inhibition with adverse side effects often observed with non-steroidal anti-inflammatory drugs. The occurrence of these phenylpropanoid esters could also explain some other pharmacological properties of M. vulgare.