Chemical Characterization and Biological Properties Assessment of Euphorbia resinifera and Euphorbia officinarum Moroccan Propolis.

Although the plants of the genus Euphorbia are largely exploited by therapists in Morocco, the composition and antibacterial activities of propolis from these plants are still unknown. To address this gap, this study aimed to characterize the pollen type, the volatile compounds, and the phenolic and mineral profiles of three Euphorbia propolis samples collected in Morocco and evaluate their antimicrobial activities. The minimum inhibitory concentration of the propolis samples was determined by the microdilution method, and the anti-adherence activity was evaluated by the crystal violet assay. The examination of anti-quorum-sensing proprieties was performed using the biosensor Chromobacterium violaceum CV026. Pollen analysis revealed that Euphorbia resinifera pollen dominated in the P1 sample (58%), while E. officinarum pollen dominated in the P2 and P3 samples (44%). The volatile compounds were primarily composed of monoterpene hydrocarbons, constituting 35% in P1 and 31% in P2, with α-pinene being the major component in both cases, at 16% in P1 and 15% in P2. Calcium (Ca) was the predominant mineral element in both E. resinifera (P1) and E. officinarum (P2 and P3) propolis samples. Higher levels of phenols, flavonoids and dihydroflavonoids were detected in the E. officinarum P2 sample. The minimum inhibitory concentration (MIC) value ranged from 50 to 450 µL/mL against Gram-positive and Gram-negative bacteria. Euphorbia propolis displayed the ability to inhibit quorum sensing in the biosensor C. violaceum CV026 and disrupted bacterial biofilm formation, including that of resistant bacterial pathogens. In summary, the current study evidences the potential use of E. officinarum propolis (P2 and P3) to combat important features of resistant pathogenic bacteria, such as quorum sensing and biofilm formation.

A Conformational-Dependent Interdomain Redox Relay at the Core of Protein Disulfide Isomerase Activity.

Aims: Protein disulfide isomerases (PDIs) are a family of chaperones resident in the endoplasmic reticulum (ER). In addition to holdase function, some members catalyze disulfide bond formation and isomerization, a crucial step for native folding and prevention of aggregation of misfolded proteins. PDIs are characterized by an arrangement of thioredoxin-like domains, with the canonical protein disulfide isomerase A1 (PDIA1) organized as four thioredoxin-like domains forming a horseshoe with two active sites, a and a', at the extremities. We aimed to clarify important aspects underlying the catalytic cycle of PDIA1 in the context of the full pathways of oxidative protein folding operating in the ER. Results: Using two fluorescent redox sensors, redox green fluorescent protein 2 (roGFP2) and HyPer (circularly permutated yellow fluorescent protein containing the regulatory domain of the H2O2-sensing protein OxyR), either unfolded or native, as client substrates, we identified the N-terminal a active site of PDIA1 as the main oxidant of thiols. From there, electrons can flow to the C-terminal a' active site, with the redox-dependent conformational flexibility of PDIA1 allowing the formation of an interdomain disulfide bond. The a' active site then acts as a crossing point to redirect electrons to ER downstream oxidases or back to client proteins to reduce scrambled disulfide bonds. Innovation and Conclusions: The two active sites of PDIA1 work cooperatively as an interdomain redox relay mechanism that explains PDIA1 oxidative activity to form native disulfides and PDIA1 reductase activity to resolve scrambled disulfides. This mechanism suggests a new rationale for shutting down oxidative protein folding under ER redox imbalance. Whether it applies to physiological substrates in cells remains to be shown.

Screening for acetylcholinesterase inhibition, lipid peroxidation inhibition and antioxidant activity of medicinal plants from Morocco / Detección de inhibición de acetilcolinesterasa, inhibición de peroxidación de lípidos y actividad antioxidante de plantas medicinales de Marruecos

Acetylcholinesterase (AChE), hydrolyzes acetylcholine to choline and acetate, thereby terminating this neurotransmitter effect at cholinergic synapses. Therefore, AChE inhibition is used for counterbalance the cholinergic deficit in Alzheimer's disease (AD) patients. In the present work, in order to find new plant acetylcholinesterase inhibitors, the hydroalcoholic extracts from seventeen medicinal plant species were screened for their acetylcholinesterase inhibition activity, as well as total phenolic (TPC) and flavonoids contents (TFC) and antioxidant activity using ORAC (Oxygen Radical Absorbance Capacity) assay, and their ability to inhibit lipid peroxidation. The results revealed that Rumex acetosa, Taraxacum officinale and Hypericum perforatum extracts possessing the highest TPC and TFC, were the most effective in terms of ORAC antioxidant activity, and acetylcholinesterase inhibition, in addition to their ability to inhibit liposomes peroxidation, suggesting that those plant species may provide a substantial source of secondary metabolites, which act as natural antioxidants and acetylcholinesterase inhibitors, and may be beneficial in the treatment of AD.

La acetilcolinesterasa (AChE) hidroliza la acetilcolina se hidroliza en colina y acetato, terminando así este efecto neurotransmisor en las sinapsis colinérgicas. Por lo tanto, la inhibición de la AChE se utiliza para contrarrestar el déficit colinérgico en pacientes con enfermedad de Alzheimer (EA). En el presente trabajo, con el fin de encontrar nuevos inhibidores de la acetilcolinesterasa vegetal, se analizaron los extractos hidroalcohólicos de diecisiete especies de plantas medicinales para determinar su actividad inhibidora de la acetilcolinesterasa, así como el contenido total de fenólicos (TPC) y flavonoides (TFC) y la actividad antioxidante utilizando ORAC (Capacidad de absorbancia de radicales de oxígeno) y su capacidad para inhibir la peroxidación de lípidos. Los resultados revelaron que los extractos de Rumexacetosa, Taraxacum officinale e Hypericum perforatum que poseen los más altos TPC y TFC, fueron los más efectivos en términos de actividad antioxidante ORAC e inhibición de acetilcolinesterasa, además de su capacidad para inhibir la peroxidación de los liposomas, sugiriendo que esas especies de plantas puede proporcionar una fuente sustancial de metabolitos secundarios, que actúan como antioxidantes naturales e inhibidores de la acetilcolinesterasa, y puede ser beneficioso en el tratamiento de la EA.

Unassisted and Carbon Dioxide-Assisted Hydro- and Steam-Distillation: Modelling Kinetics, Energy Consumption and Chemical and Biological Activities of Volatile Oils.

The demand for more suitable eco-friendly extraction processes has grown over the last few decades and driven research to develop efficient extraction processes with low energy consumption and low costs, but always assuring the quality of the volatile oils (VOs). The present study estimated the kinetic extraction and energy consumption of simultaneous hydro- and steam-distillation (SHSD), and SHSD assisted by carbon dioxide (SHSDACD), using an adopted modelling approach. The two isolation methods influenced the VOs yield, chemical composition and biological activities, namely, antioxidant, anti-glucosidase, anti-acetylcholinesterase and anti-inflammatory properties. SHSDACD provided higher VOs yields than the SHSD at a shorter extraction time: 2.8% at 30 min vs. 2.0% at 120 min, respectively, for Rosmarinus officinalis, 1.5% at 28 min vs. 1.2% at 100 min, respectively, for Lavandula angustifolia, and 1.7% at 20 min vs. 1.6% at 60 min, respectively, for Origanum compactum. The first order and sigmoid model fitted to SHSD and SHSDACD, respectively, with R2 value at 96% and with mean square error (MSE) < 5%, where the k distillation rate constant of SHSDACD was fivefold higher and the energy consumption 10 times lower than the SHSD. The rosemary SHSD and SHSDACD VOs chemical composition were similar and dominated by 1,8-cineole (50% and 48%, respectively), and camphor (15% and 12%, respectively). However, the lavender and oregano SHSDACD VOs were richer in linalyl acetate and carvacrol, respectively, than the SHSD VOs. The SHSDACD VOs generally showed better capacity for scavenging the nitric oxide and superoxide anions free radicals as well as for inhibiting α-glucosidase, acetylcholinesterase, and lipoxygenase.

Simultaneous Hydrodistillation-Steam Distillation of Rosmarinus officinalis, Lavandula angustifolia and Citrus aurantium from Morocco, Major Terpenes: Impact on Biological Activities.

Interest in the use of essential oils (EOs) in the biomedical and food industries have seen growing over the last decades due to their richness in bioactive compounds. The challenges in developing an EO extraction process that assure an efficient levels of monoterpenes with impact on biological activities have driven the present study, in which the EO extraction process of rosemary, lavender and citrus was performed by simultaneous hydrodistillation-steam distillation, and the influence of EO composition on biological activities, namely antioxidant, anti-inflammatory, antidiabetic, anti-acetylcholinesterase, anti-tyrosinase, antibacterial, and antibiofilm activity, were evaluated. The EO yields of combinations were generally higher than the individual plants (R. officinalis (Ro), L. angustifolia (La), and C. aurantium (Ca)) extracted by the conventional hydrodistillation. The EOs obtained by this process generally had a better capacity for scavenging the free radicals, inhibiting α-glucosidase, and acetylcholinesterase activities than the individual EOs. The combination of EOs did not improve the ability for scavenging peroxide hydrogen or the capacity for inhibiting lipoxygenase activity. The antioxidant activity or the enzyme inhibition activity could not only be attributed to their major compounds because they presented lower activities than the EOs. The chemical composition of the combination Ro:La:Ca, at the ratio 1/6:1/6:2/3, was enriched in 1,8-cineole, linalool, and linalyl acetate and resulted in lower MIC values for all tested strains in comparison with the ratio 1/6:2/3:1/6 that was deprived on those components. The biofilm formation of Gram positive and Gram negative bacteria was impaired by the combination Ro:La:Ca at a sub-inhibitory concentration.

Comparative Study of the Antioxidant and Enzyme Inhibitory Activities of Two Types of Moroccan Euphorbia Entire Honey and Their Phenolic Extracts.

Honey is a natural food product very famous for its health benefits for being an important source of antioxidant and phenolic compounds. Euphorbia honeys obtained from different regions of Morocco were evaluated for their ability to inhibit acetylcholinesterase, lipoxygenase, tyrosinase and xanthine oxidase activities. Their antioxidant properties were evaluated using the: 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging capacity, nitric oxide scavenging activity (NO) and scavenging ability of superoxide anion radical. Then, the phenolic extracts of the same entire honey samples were evaluated by liquid chromatography coupled to diode array detection and mass spectrometry (LC-DAD-MS) and tested for the biological activities previously evaluated on the entire honeys, in order to conduct a comparative study between both (honey and phenolic extracts). The chromatographic profiles for the studied Euphorbia honey extracts were different. Phenolic compounds gallic acid, 4-hydroxybenzoic acid and p-coumaric acid were detected in all samples, whereas kampferol was only present in two samples. Physicochemical parameters and total phenolic content were also determined. Entire honey that recorded the highest rate of phenols was sample M6 (E. resinifera) = 69.25 mg GAE/100 g. On the other hand, the phenolic extracts had better antioxidant and enzyme inhibitory activities than the entire honeys, regardless the monofloral honey type. In conclusion, the studied Euphorbia honeys may have a great potential as antioxidant, anti-inflammatory and anti-tyrosinase sources for pharmaceutical and cosmetic applications.

Influence of Geographic Origin and Plant Source on Physicochemical Properties, Mineral Content, and Antioxidant and Antibacterial Activities of Moroccan Propolis.

This research is aimed at determining the physicochemical properties (resin, wax, balsams, pH, moisture, ash, and mineral contents) of propolis samples collected from different geographical areas in Morocco, as well as evaluating the antioxidant and antibacterial activities of these samples. The results showed the following values for physicochemical analysis: resin (17.42-58.01%), wax (21.31-70.12%), balsam (0.27-2.12%), pH (3.7-5.3), moisture (1.02-3.65%), and ash (0.72-5.01%). The phenolic and flavone/flavonol contents of samples were ranged between 6.74 mg FAE/g and 149.13 mg FAE/g and between 1.19 mg QE/g and 108.11 mg QE/g, respectively. The sample P3 presented also the strongest radical scavenging activity toward DPPH, ABTS free radicals, and FRAP assay with IC50 values of 0.021, 0.026, and 0.042 mg/mL, respectively. All propolis samples showed significant inhibitory effects against all tested microorganisms with MICs ranging from 0.28 mg/mL to 1.12 mg/mL for Gram-negative strains and from 0.002 mg/mL to 1.12 mg/mL for Gram-positive strains. A strong correlation was found between resin, total phenolic compounds, flavones/flavonols, and antioxidant activity. Linear discriminant analysis revealed that the samples studied were divided into two groups which were differentiated by the data of antioxidant activity, mineral contents, and antibacterial activity. It can be concluded that the physicochemical properties, mineral content, and biological activities of Moroccan propolis depend on their geographical and botanical origin.

Antioxidant activity and enzyme inhibitory potential of Euphorbia resinifera and E. officinarum honeys from Morocco and plant aqueous extracts.

Natural products may be applied in a wide range of domains, from agriculture to food and pharmaceutical industries. In this study, the antioxidant properties and the capacity to inhibit some enzymatic activities of Euphorbia resinifera and Euphorbia officinarum aqueous extracts and honeys were assessed. The physicochemical characteristics were also evaluated. Higher amounts of iron, copper and aluminium were detected in E. officinarum honey, which may indicate environmental pollution around the beehives or inadequate storage of honey samples. This honey sample showed higher amounts of total phenols and better capacity for scavenging superoxide anion free radicals and DPPH free radicals as compared with E. resinifera honey, but poorer capacity for inhibiting lipoxygenase, acetylcholinesterase, tyrosinase and xanthine oxidase. The ratio plant mass:solvent volume (1:100) and extraction time (1 - 2 h) were associated with higher total phenols and better antioxidant activities and lipoxygenase, acetylcholinesterase and tyrosinase inhibitory activities, regardless of the plant species. The aqueous extracts had systematically higher in vitro activities than the respective honey samples.

Preliminary screening of the possible protective effect of Moroccan propolis against chromium-induced nephrotoxicity in animal model.

BACKGROUND AND AIM: Hexavalent chromium (Cr (VI)) compounds have been shown to induce nephrotoxicity associated with oxidative stress in humans and animals. The aim of the present study was to investigate the nephroprotective effect of bee propolis, as highly antioxidant natural product, in vivo using an animal model. MATERIALS AND METHODS: First of all, total phenol and flavonoid contents of propolis sample were estimated in vitro. Afterward, to study the protective effect of propolis on renal damages caused by an injection of a single dose of potassium dichromate (15 mg/kg b.wt), 24 male Wister rats were divided into test and control groups. Propolis treatment was performed by oral gavage of 100 mg/kg b.wt/day, while the control groups received water instead. The 24 h urine was collected and blood samples were withdrawn before and after each treatment for further analysis. RESULTS: Propolis revealed to be rich in polyphenols and flavonoids. Chromate provoked a nephrotoxic effect expressed by a drastic decrease in glomerular filtration assessed by creatinine clearance. However, the administration of propolis attenuated the renal damages induced by the chromate. This attenuation can be seen by the increase of creatinine clearance when comparing propolis treated group to the non-treated group. CONCLUSION: Propolis showed a protective potential against chromate-induced nephrotoxicity through the amelioration of chromate's toxic effects. It might be concluded that propolis could be effective as chemoprotectant in the management of potassium dichromate-induced nephrotoxicity.

Natural antioxidants in emulsions O/W.

This study compared the capacity of propolis extract (PE) and thyme waste extract (TWE) to prevent the oxidation of oil in water (O/W) emulsion, as well as their impact on emulsion apparent viscosity (AV) in the presence of wheat germ and almond oils as lipid phase. For this, central composite design (CCD) and principal component analysis (PCA) were performed. Oxidation process was monitored by evaluating the formation of primary and secondary lipid oxidation products, at the same time the AV behavior was determined evaluating consistency index and flow behavior index. The results revealed that the increase of PE% and TWE% decreases TBARS (Thiobarbituric Acid Reactive Substances) and hydroperoxides formation. Viscosity increases with the rise of TWE% over (0.04%), whereas lower concentrations of PE% decreases it. Those results have been confirmed in the PCA analysis. TWE showed higher resistance to oxidation, although PE was more effective as antioxidant than TWE.

Antioxidant Activity of Thyme Waste Extract in O/W Emulsions.

Thymus vulgaris (thyme) is an aromatic plant and its essential oil has been applied as antimicrobial and antioxidant due to the presence of phenolic compounds. However, after steam distillation, the deodorized plant material is rejected, despite the possible presence of bioactive compounds. Ethanolic thyme waste extract revealed the presence of benzoic acid, 4-hydroxybenzoic acid, ferulic acid, caffeic acid, and sinapic acid. This waste thyme extract had the capacity for preventing the formation of primary and secondary lipid oxidation products in emulsions O/W (oil in water), constituted by diverse proportions of wheat and almond oils, without interfering with the viscosity parameters, for 10 weeks, at 37 °C. The increasing proportion of almond oil (≥50%) in the emulsion increases its resistance to oxidation, which is improved with the presence of an optimal concentration of tested thyme waste extract (0.02% and 0.04%). The waste thyme extract can, therefore, be used as an antioxidant either in food or pharmaceutical emulsions O/W, replacing the synthetic antioxidants.

Insight on Propolis from Mediterranean Countries: Chemical Composition, Biological Activities and Application Fields.

This review updates the information upon the chemical composition of propolis from all Mediterranean countries as well as their biological properties and applications. The non-volatile fraction of propolis was characterized by the presence of phenolic acids and their esters and flavonoids. Nevertheless, in some countries, diterpenes were also present: Sicily (Italy), Croatia, Malta, Creta (Greece), Turkey, Cyprus, Egypt, Libya, Algeria and Morocco. The volatile fraction of propolis was characterized by the presence of benzoic acid and its esters, mono- and sesquiterpenes, being the oxygenated sesquiterpene ß-eudesmol characteristic of poplar propolis, whereas the hydrocarbon monoterpene α-pinene has been related with the presence of conifers. Regardless the chemical composition, there are common biological properties attributed to propolis. Owing to these attributes, propolis has been target of study for applications in diverse areas, such as food, medicine and livestock.

Potential therapeutic effect of Moroccan propolis in hyperglycemia, dyslipidemia, and hepatorenal dysfunction in diabetic rats.

OBJECTIVES: The effect of propolis collected in Morocco on blood glucose, lipid profile, liver enzymes, and kidney function was investigated in control and diabetic rats. MATERIALS AND METHODS: Antioxidant activity of propolis was evaluated with the use of DPPH, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS•+), ferric reducing power and total antioxidant activity assay. To study its effect in streptozotocin (STZ)-induced diabetes, the rats were divided into eight groups; four control and four diabetics. The animals received distilled water, glibenclamide, or propolis extract, 50 mg/kg/BW) or 100 mg/kg/b.wt, daily for 15 days. Blood glucose, triglyceride, lactic acid dehydrogenase, liver enzymes, creatinine, blood urea, lipid profile, and body weight were measured on day 15 after commencement of the treatment. RESULTS: Propolis has a strong antioxidant activity and high total flavonoids and polyphenols content. Glibenclamide and propolis have no significant effect on lipid parameters, and renal and hepatic function in non-diabetic rats. However, propolis or glibenclamide caused a significant lowering of blood glucose after a single administration and at day 15 after daily administration in diabetic rats (P<0.05). Both interventions significantly lowered lactic acid dehydrogenase, increased body weight, and ameliorated dyslipidemia and abnormal liver and kidney function caused by diabetes. The effect of propolis was dose-dependent and in a high dose it was more potent than glibenclamide. CONCLUSION: Propolis exhibited strong antihyperglycemic, antihyperlipidemic, and hepato-renal protective effects in diabetes, and significantly lowered the elevated lactic acid dehydrogenase. The study demonstrated for the first-time the effect of Moroccan propolis in diabetes and it will pave the way for clinical investigations.

Effect of poplar-type propolis on oxidative stability and rheological properties of O/W emulsions.

Propolis is known to possess antioxidant activity. However, there is no information on this activity in emulsions O/W. The protective effect of propolis on the oxidation and rheological properties of emulsions O/W containing wheat germ and almond oils was evaluated. Emulsions O/W were prepared with different concentration of propolis extract, almond oil and wheat germ oil. All emulsions physically stable without phase separation were stored at 37 °C for 9 weeks. Chemical composition of propolis was established by Gas chromatography coupled to mass spectrometry. Rheological characterization of different emulsions was performed evaluating consistency index and flow behavior index. The oxidation was monitored by measuring the lipid hydroperoxides and thiobarbituric acid-reactive substances (TBARS) methods. Flavonoids, phenolic acid esters, and aromatic acids were the main groups of compounds found in propolis. The results showed that popolis was good antioxidant in the concentration of 0.02 and 0.04% when lipid phase was constituted by almond oil. The rheological behavior is typical of a non-Newtonian fluid, being almond oil more adequate for having a higher stable O/W emulsion.

Moroccan Propolis: A Natural Antioxidant, Antibacterial, and Antibiofilm against Staphylococcus aureus with No Induction of Resistance after Continuous Exposure.

This study was performed to evaluate the total phenols, flavonoids, and antioxidant activities of twenty-four propolis samples from different regions of Morocco. In addition, two samples were screened regarding the antibacterial effect against four Staphylococcus aureus strains. Gas chromatography coupled to mass spectra (GC-MS) analysis was done for propolis samples used in antibacterial tests. The minimum inhibitory and minimum bactericidal concentration (MIC, MBC) were determined. The potential to acquire the resistance after sequential exposure of bacterial strains and the impact of adaptation to propolis on virulence using the Galleria mellonella were evaluated. Additionally, the effects of propolis extract on the bacterial adherence ability and its ability to inhibit the quorum sensing activity were also examined. Among the twenty-four extracts studied, the samples from Sefrou, Outat el Haj, and the two samples marketed in Morocco were the best for scavenging DPPH, ABTS, NO, peroxyl, and superoxide radicals as well as in scavenging of hydrogen peroxide. A strong correlation was found between the amounts of phenols, flavonoids, and antioxidant activities. Propolis extract at the MIC value (0.36 mg/mL) significantly reduced (p < 0.001) the virulence potential of S. aureus ATCC 6538 and the MRSA strains without leading to the development of resistance in the sequence of continuous exposure. It was able to impair the bacterial biofilm formation. The results have revealed that sample 1 reduces violacein production in a concentration dependent manner, indicating inhibition of quorum sensing. This extract has as main group of secondary metabolites flavonoids (31.9%), diterpenes (21.5%), and phenolic acid esters (16.5%).

Antioxidant and diuretic activity of co-administration of Capparis spinosa honey and propolis in comparison to furosemide.

OBJECTIVE: To study the antioxidant properties of Capparis spinosa (C. spinosa) honey and propolis and the effect of combined honey and propolis administration on urine volume and electrolytes in rats. METHODS: C. spinosa honey [1000 mg/kg body weight (b.wt)], propolis (100 mg/kg b.wt), honey/propolis mixture (C. spinosa honey 1000 mg/kg b.wt/ propolis extract 100 mg/kg b.wt ), distilled water (1 mL/kg b.wt) and furosemide (10 mg/kg b.wt) were orally administered to five groups of rats for 21 d. Urine volume, blood and urine sodium, potassium and chloride were measured. The antioxidant activity of propolis and honey was assessed and their total phenols and flavonoids were determined. RESULTS: Propolis and C. spinosa honey contain polyphenols including flavonoids and propolis demonstrated higher antioxidant activities than honey. Honey significantly increased urine volume and urine electrolyte excretion. Propolis had no significant effect on urine volume, but co-administration of propolis and honey caused significant diuresis. No major changes were observed in plasma electrolytes with the use of honey, propolis or their combination. CONCLUSIONS: Honey and propolis have antioxidant activity and contain polyphenols including flavonoids that are more pronounced in propolis. Honey has a significant diuretic activity alone or in combination with propolis. This is the first study comparing the diuretic effect of co-administration of propolis and C. spinosa honey with furosemide.

Impact of Biohybrid Magnetite Nanoparticles and Moroccan Propolis on Adherence of Methicillin Resistant Strains of Staphylococcus aureus.

Biofilm bacteria are more resistant to antibiotics than planktonic cells. Propolis possesses antimicrobial activity. Generally, nanoparticles containing heavy metals possess antimicrobial and antibiofilm properties. In this study, the ability of adherence of Methicillin Resistant Strains of Staphylococcus aureus (MRSA) to catheters treated with magnetite nanoparticles (MNPs), produced by three methods and functionalized with oleic acid and a hydro-alcoholic extract of propolis from Morocco, was evaluated. The chemical composition of propolis was established by gas chromatography mass spectrometry (GC-MS), and the fabricated nanostructures characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Mossbauer spectroscopy and Fourrier transform infrared spectroscopy (FTIR). The capacity for impairing biofilm formation was dependent on the strain, as well as on the mode of production of MNPs. The co-precipitation method of MNPs fabrication using Fe(3+) and Na2SO3 solution and functionalized with oleic acid and propolis was the most effective in the impairment of adherence of all MRSA strains to catheters (p < 0.001). The adherence of the strain MRSA16 was also significantly lower (p < 0.001) when the catheters were treated with the hybrid MNPs with oleic acid produced by a hydrothermal method. The anti-MRSA observed can be attributed to the presence of benzyl caffeate, pinocembrin, galangin, and isocupressic acid in propolis extract, along with MNPs. However, for MRSA16, the impairment of its adherence on catheters may only be attributed to the hybrid MNPs with oleic acid, since very small amount, if any at all of propolis compounds were added to the MNPs.

Antioxidant, Anti-inflammatory and Anti-hyperglycaemic Activities of Essential Oils from Thymbra capitata, Thymus albicans, Thymus caespititius, Thymus carnosus, Thymus lotocephalus and Thymus mastichina from Portugal.

The in viro antioxidant, anti-inflammatory, anti-hyperglycaemic, and anti-acetylcholinesterase activities of the essential oils (EOs) isolated from six Lamiaceae species (Thymbra capitata,. Thymus albicans, Th. caespititius, Th. carnosus, Th. lotocephalus and Th. mastichina) grown in Portugal, were evaluated. Th. caespititius and T. capitata carvacrol/thymol-rich EOs showed the best capacity for preventing lipid peroxidation, and scavenging the 2,2'-azino- bis(3-ethylbenzothiazoline-6-sulphonid acid) (ABTS) and peroxyl free radicals, as well as for inhibiting lipoxygenase and a-amylase. However, Th. caespititius and Th. lotocephalus 1,8-cineole and linalool rich EOs were the best inhibitors of a-glucosidase. T capitata, Th. lotocephalus and Th. albicans EOs were the: most active for inhibiting acetyleholinesterase. Th. caespititius and Th. mastichina EOs were the main scavengers of nitric oxide (NO) radicals. The comparison between the present data with a survey of the existing literature on the in vitro biological activities of the essential oils isolated from the same species from Portuguese origin, using other.methodologies, showed some differences. For instance the use of two oxidizable substrates (egg yolk andlecithin liposomes) led to distinct results mainly for those samples with relatively low activity. In addition, the EOs capacity for scavenging peroxyl radicals-was also influenced by the presence of cyclodextrins, as a synergism seemed to occur between EOs and those carbohydrates.