Antimicrobial, Multidrug Resistance Reversal and Biofilm Formation Inhibitory Effect of Origanum majorana Extracts, Essential Oil and Monoterpenes.

Origanum majorana L. is a widely used medicinal plant; its distilled oil and preparations are extensively utilised in the phytotherapy and food industries. The objective of this study is to evaluate the extracts and the essential oil (EO) of Origanum majorana L, and its monoterpenes for antimicrobial, bacterial multidrug resistance reversing, and biofilm formation inhibitory potency. The composition of EO and n-hexane extract was characterized by GC-MS. In the essential oil terpinen-4-ol (24.92%), trans-sabinene hydrate (25.18%), γ-terpinene (6.48%), cis-sabinene hydrate (5.44%), p-cymene (4.72%), sabinene (4.53%), α-terpineol (4.43%), and α-terpinene (3.00%) were found as the main constituents while trans-sabinene hydrate (1.43%), and terpinen-4-ol (0.19%) were detected in the n-hexane extract besides a series of hydrocarbons. The antibacterial activity of EO and terpinen-4-ol, α-terpinene, and linalool was also assessed against sensitive and drug-resistant S. aureus, and E. coli strains with MIC values of 0.125-0.250% and 30-61 µM, respectively. In the efflux pump (EP) inhibitory assay, made by the ethidium bromide accumulation method in E. coli ATCC 25922, and AG100 and S. aureus ATCC 25923, and MRSA ATCC 43300 strains, EO exhibited substantial activity, especially in the E. coli ATCC 25922 strain. Among the EO constituents, only sabinene was an EP inhibitor in sensitive Escherichia strain. In the case of S. aureus strains, EO and sabinene hydrate exhibited moderate potency on the drug-resistant phenotype. The antibiofilm effects of the samples were tested by crystal violet staining at sub-MIC concentration. γ-Terpinene, terpinen-4-ol, sabinene, sabinene hydrate and linalool were found to be effective inhibitors of biofilm formation (inhibition 36-86%) on E. coli ATCC 25922 and S. aureus MRSA ATCC 43300, while EO was ineffective on these strains. In contrast to this, biofilms formed by E. coli AG100 and S. aureus ATCC 25923 were significantly inhibited by the EO; however, it was not affected by any of the monoterpenes. This observation suggests that the antibiofilm effect might be altered by the synergism between the components of the essential oil.

Evidence Supports Tradition: The in Vitro Effects of Roman Chamomile on Smooth Muscles.

The dried flowers of Chamaemelum nobile (L.) All. have been used in traditional medicine for different conditions related to the spasm of the gastrointestinal system. However, there have been no experimental studies to support the smooth muscle relaxant effect of this plant. The aim of our research was to assess the effects of the hydroethanolic extract of Roman chamomile, its fractions, four of its flavonoids (apigenin, luteolin, hispidulin, and eupafolin), and its essential oil on smooth muscles. The phytochemical compositions of the extract and its fractions were characterized and quantified by HPLC-DAD, the essential oil was characterized by GC and GC-MS. Neuronally mediated and smooth muscle effects were tested in isolated organ bath experiments on guinea pig, rat, and human smooth muscle preparations. The crude herbal extract induced an immediate, moderate, and transient contraction of guinea pig ileum via the activation of cholinergic neurons of the gut wall. Purinoceptor and serotonin receptor antagonists did not influence this effect. The more sustained relaxant effect of the extract, measured after pre-contraction of the preparations, was remarkable and was not affected by an adrenergic beta receptor antagonist. The smooth muscle-relaxant activity was found to be associated with the flavonoid content of the fractions. The essential oil showed only the relaxant effect, but no contracting activity. The smooth muscle-relaxant effect was also detected on rat gastrointestinal tissues, as well as on strip preparations of human small intestine. These results suggest that Roman chamomile extract has a direct and prolonged smooth muscle-relaxant effect on guinea pig ileum which is related to its flavonoid content. In some preparations, a transient stimulation of enteric cholinergic motoneurons was also detected. The essential oil also had a remarkable smooth muscle relaxant effect in this setting. Similar relaxant effects were also detected on other visceral preparations, including human jejunum. This is the first report on the activity of Roman chamomile on smooth muscles that may reassure the rationale of the traditional use of this plant in spasmodic gastrointestinal disorders.

Chemical composition of essential oils of Grindelia squarrosa and G. hirsutula.

The essential oils of Grindelia squarrosa (Pursh) Dunal and G. hirsutula Hook. & Am. cultivated in Romania were isolated by hydrodistillation. The essential oils were analyzed by a combination of GC-FID and GC-MS. The identification of the constituents was achieved from their retention indices and comparison of their MS data with computer library database and literature data. The fifty-six identified constituents accounted for 72.1-81.3% of the oils. The oils were found to contain a-pinene, beta-pinene, limonene, borneol, bornyl acetate and germacrene D as main constituents. The oils obtained from the two species showed small differences in chemical composition. However, menthol, menthone and pulegone were detected only in the essential oil of G. hirsutula.

Volatile glycosides from the leaves of Morus alba with a potential contribution to the complex anti-diabetic activity.

The leaves and root bark of Morus alba, the white mulberry tree, are well-known traditional medicines for the treatment of type II diabetes. Several different types of constituents have been suggested to be responsible for the anti-diabetic activity of mulberry drugs, such as iminosugars, flavonoids and other phenolic compounds, glycopeptides and ecdysteroids. Our group recently suggested that a volatile-oil like fraction of the hot water extract of M. alba leaves, containing several phenyl-propane derivatives, can increase the glucose consumption of adipocytes. Here we report the isolation of three glycosylated volatile constituents from mulberry leaves, two megastigmane derivatives along with the beta-D-glucoside of eugenol. Furthermore, a commercially available mixture of probiotic bacteria was assessed to study the effect of the intestinal flora on the megastigmane derivatives. Significant amounts of the aglycons of both compounds were liberated, suggesting that these compounds can be metabolized in the large intestines and absorbed without the sugar moiety after the consumption of a traditional mulberry tea. Based on literature data, both the glycosides and their aglycons have a potential contribution to the beneficial effects of mulberry leaves in type 2 diabetes.

In vitro anti-diabetic activity and chemical characterization of an apolar fraction of Morus alba leaf water extract.

The tea from the white mulberry (Morus alba L.) leaf is a worldwide known traditional medicine of type II diabetes. Here, we report the investigation of the dichloromethane-soluble fraction obtained in a 0.24% m/m yield from the hot water extract of mulberry leaves. A significant, dose-dependent activity was found by means of the 24-h glucose consumption of fully differentiated adipocytes both in the absence and presence of insulin. The fraction was characterized by HPLC-DAD, GC-MS and GC-FID. The main constituent (40.3% by means of GC-FID) was isolated and identified as loliolide by EIMS, HRESIMS and NMR spectroscopy. In the active fraction benzyl alcohol, ethyl benzoate, t-cinnamic acid, p-hydroxyacetophenone, t-coniferyl alcohol and synapil alcohol were also identified by GC-MS and quantified by GC-FID (0.7, 1.3, 1.5, 2.9, 7.5 and 2.6%, respectively).

Antifungal activity and composition of essential oils of Conyza canadensis herbs and roots.

Essential oils from herbs and roots of Conyza canadensis (horseweed), collected in Hungary, were obtained by hydrodistillation. The chemical compositions of the oils were analysed by combination of GC and GC/MS. The major constituent of the oil obtained from the aerial parts of horseweed was limonene (78%), while the main component of root oil was 2Z,8Z-matricaria ester. The antimicrobial activities of the oils were tested on Gram-positive (Enterococcus faecalis, Staphylococcus aureus, and Streptococcus pyogenes), Gram-negative (Escherichia coli, Pseudomonas aeruginosa) bacteria, reference fungal strains, and fungal strains isolated from patients (Candida, Cryptococcus, Trichophyton, Rhodotorula, and Aspergillus) by agar disc diffusion and broth dilution methods. None of the oils showed any activity against the tested bacterial strains, but exhibited moderate-to-strong activity against all fungi with the only exception of A. fumigatus. The highest zone of inhibition was observed in case of Cryptococcus neoformans and Trichophyton interdigitalis.

Analysis of the essential oil of Amsonia illustris.

The root and leaf essential oils, present in trace amounts in Amsonia illustris Woods. (Apocynaceae), were isolated by steam distillation and their chemical constituents identified by GC-FID and GC-MS. More than 80% of the thirty volatile compounds in the leaf oil were identified, the major constituents being mainly sesquiterpenes like a-humulene (14.5%), beta-caryophyllene (12.4%) and guaiol (11.6%). The volatile ingredients of the root oil were pinocampheol, methyl salicylate, (2E,4E)- decadienal, eugenol and trans-isoeugenol.

[Dietary supplements on the domestic market adulterated with sildenafil and tadalafil]. / Szildenafillal és tadalafillal hamisított étrend-kiegészítok a hazai piacon.

Mandatory requirements regulating the manufacture and sale of dietary supplements are much less stringent than those related to pharmaceuticals. Hence, the sheer number and diversity of marketed products in this category has shown an unprecedented increase Europe-wide. Not surprising, that cases for incorrect marketing/promotion, incorrect recommendations for product use, as well as reported incidents of questionable product quality and/or deliberate adulterations have also become frequent in recent years. Typical adulterations consist of admixtures of synthetic pharmaceuticals to the matrix fraudulently declared to consist exclusively of extracts of various (medicinal) plants. In the present paper, the results of qualitative investigations of ten plant-based preparations, marketed in Hungary, and recommended as (or alleged to be) natural aphrodisiacs, are reported. Sildenafil and/or tadalafil or related analogs were detected in six of the ten products. These results highlight, once more, the unacceptable risks for the consumers of such adulterated dietary supplements.