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Nigella sativaL.‘Black cumin’ (Ranunculaceae) is one of the plants commonly used in Moroccan folk medicine for treatment of various ailments including diabetes mellitus. The present study was undertaken to investigate the effect of differentN. sativaseed extracts on insulin secretion. Different fractions of the seed were prepared: the defatted fraction (HR II), which was divided into two subfractions: the first (HR III) containing acidic and neutral compounds and the second (HR IV) containing basic compounds. The insulin secretory effects of these extracts were evaluated individually at different concentrations (0.01, 0.1, 1 and 5 mg/mL), in vitro in isolated rat pancreatic islets in the presence of 8.3 mmol/L glucose. The results show that addition of the defatted whole extract or of the basic subfraction of the seed in the incubation medium significantly increased glucose-induced insulin release from the islets. In the case of the acidic and neutral subfraction, the stimulatory effect was observed only for the higher concentration (5 mg/mL). However, a clear concentration-dependent increase in insulin release from isolated pancreatic islets was observed for the basic subfraction. Our data show that the antidiabetic properties ofN. sativaseeds may be, at least partly, mediated by stimulated insulin release, and that the basic subfraction largely contributes to this stimulatory effect. Further phytochemical studies are underway in order to isolate the pharmacological compound(s) responsible for the insulinotropic effect ofN. sativaseeds. [ABSTRACT FROM AUTHOR]

Sargassum muticum, a Japanese brown seaweed, has recently invaded various shorelines throughout the world, including the Atlantic coast of Morocco, where it has developed significant populations. We report on the use of these algae as a partial replacement of Portland cement in cement paste as part of a long-term plan to combat this invasive seaweed. With a fixed water to cement ratio (W/C = 0.45), algae powder is added at 5%, 10%, 15% and 20% from the cement content in producing cement pastes. The hydration process was assessed using impedance spectroscopy throughout the setting period from 10 min to 28 days. Compressive strength tests were performed at 7, 14 and 28 days. An equivalent circuit model has been proposed. The results showed that the various strength properties of the cement paste increased or decreased with addition of algae powder. The compressive strength tends to increase with the addition of algae powder. This study shows that 10% addition of algae powder to cement paste showed an increase in compressive strength and when the addition increased to 20% the properties started to decrease. [ABSTRACT FROM AUTHOR]

In the present work, further analysis of complex conductivity was carried out. In particular, the first derivative of the ac conductivity of polysaccharide solutions provides a good differentiation of the different contributions of the conductivity. Moreover, this procedure allowed us to prove and confirm the validity of the equivalent circuit. In addition, a new electrical circuit was proposed to fit the complex conductivity. The main aim is focused on the analysis of the change in the electrical properties involved in the Cole–Cole relaxation process at medium and high frequencies, which in turn allowed us to extract crucial parameters such as ionic strength, dc conductivity, and relaxation time. It is found that their evolutions as a function of concentration revealed a clear transition at 5% (w/v), suggesting the transition from the dilute to the semi-dilute domain due to the cross-linking between polyvalent counterions and chains molecular. [ABSTRACT FROM AUTHOR]

The rheological properties and spectrum infrared of polysaccharides extracted from Cystoseira myriophylloides algae were investigated in the concentrations range from 3 to 9% (w/v) and at different temperatures. Results of rheological characteristics in a steady shear rate showed pseudoplastic properties and the dynamic rheological properties showed a fluid-like viscoelastic behavior. The flow and viscoelastic characteristics of polysaccharides were described using the power-law (the Ostwald model). The values of flow behavior index of the sample were close to unity (0.91) for 3% and it decreased up to 0.71 for 9% revealing the shear-thinning (pseudoplastic) nature of these polysaccharides. Moreover, the consistency coefficient increased non-linearly with concentration and it was described by a power law. The flow behavior as a function of temperature was satisfactorily described using the Arrhenius law and the activation energy values were extracted. It decreased from 15.68 and 17.21 kJ/mol when the concentration increased from 5 to 9% (w/v). Additionally, in dynamic rheological measurements, tan δ > 1 and G″ > G′ reveling a shear-thinning behavior. Finally, the analysis of the FTIR spectra of these polysaccharides showed the presence of uronic acid groups. This behavior would suggest that polysaccharides extracted from Cystoseira myriophylloides could be an interesting additive as thickeners. [ABSTRACT FROM AUTHOR]

To explore the potential of new ecological corrosion inhibitors, we investigated the mechanism of corrosion inhibition in carbon steel using Halopitys incurvus, an algal extract available in both crude and chromatographic fractions, in a 0.5 M H2SO4 medium. Various methods were employed, including gravimetry, electrochemical impedance spectroscopy, polarization curves, scanning electron microscopy (SEM) techniques, and molecular dynamics. The crude extract exhibited a high corrosion‐inhibiting potential, with a maximum inhibitory efficiency of 85.30% at 600 mg/L. The electrochemical results indicated mixed behavior of the crude extract. Furthermore, we found that the adsorption of the crude extract onto the metal surface followed the Langmuir isotherm pattern. The SEM study confirmed our proposition that extract molecules were adsorbed onto the carbon steel surface. Using the chromatographic fractionation protocol, we were able to distinguish four main fractions, and the most effective fractions reached an inhibitory efficiency value of 96.00% at 100 mg/L. The molecular dynamics simulation confirmed the experimental results. [ABSTRACT FROM AUTHOR]

Euphorbia resinifera (Zaggûm or Tikiut) is an endemic species of Morocco that grows in the Middle Atlas Mountain range. It is used in folk medicine to treat several diseases, especially various types of cancer. Aim of the review: In this review, we critically highlighted and discussed previous reports on E. resinifera, concerning its botanical description, taxonomy, geographical distribution, and medicinal use. In addition, bioactive compounds, toxicology, and pharmacological effects were reported. Materials and methods: We searched various scientific databases, such as Scopus, PubMed, Web of Science, SpringerLink, SciFinder, Wiley Online, and Google Scholar, to collect data on E. resinifera. Studies involving E. resinifera or its bioactive compounds with regards to antitumor, anti-inflammatory, antileishmanial, antiprotease, immunomodulatory, irritant, and lysosomal activities are discussed here. Results: E. resinifera has been widely used in folk medicine practice in Morocco to treat several diseases such as diabetes, cancer, and inflammatory skin conditions, as well as to heal wounds. In phytochemistry studies, biochemical compounds have been identified from E. resinifera belonging specially to terpenoids. Indeed, in vitro and in vivo pharmacological investigations showed that extracts and compounds from the latex of E. resinifera exhibited a wide spectrum of biological properties, particularly antioxidant, antimicrobial, antitumor, anti-inflammatory, antileishmanial, and immunomodulatory and neuroprotective activities. Conclusion: The use of E. resinifera in conventional medicine is supported by processes founded on biological evidence. However, in-depth research is necessary to prove the safety and efficacy of E. resinifera latex extracts and their compounds and to clarify their pharmacological mechanisms. In addition, pharmacokinetic and pharmacodynamics studies are required for extracts and bioactive compounds. [ABSTRACT FROM AUTHOR]

• This study investigates the temperature dependence of complex conductivity of polysaccharides. • The electrical circuit model analyzes conductivity vs. frequency, giving analytical functions for each relaxation process. • Extrapolation and deconvolution approaches identified three distinct relaxation processes. • All relaxation processes showed thermally activated behavior, with parameters following Arrhenius law. • Linear correlation was established between activation energy values and electrical parameters for each relaxation process. The evolution of the complex conductivity of raw polysaccharides extracted from Cystoseira myriophyloides algae exhibited significant temperature dependence in an aqueous solution. An analysis of the complex conductivity versus frequency was conducted using an appropriate electrical circuit based on our theoretical approach. This facilitated the generation of analytical functions representing the relaxation processes occurring at different temperatures. Subsequently, extrapolation and deconvolution procedures were employed to further investigate and identify all relaxation processes and their origins. These approaches revealed the presence of three relaxation processes. The first relaxation, observed at low frequency, is attributed to interfacial polarization between the electrode and the solution. The second and third relaxations, observed at medium and high frequencies, are attributed to bulk relaxation processes. Then, subtracting the low-frequency process clarified the bulk relaxation processes. Both relaxations are described by the Cole-Cole relaxation, which effectively models the well-known Maxwell-Wagner-Sillars (MWS) phenomenon typically observed in polyelectrolyte solutions. This relaxation is typically caused by interfacial polarization between molecular chains and counterions in the sample. Both relaxations were found to be thermally activated. The temperature dependence of useful parameters extracted from each relaxation, such as relaxation time (τ σ) and conductivity (σ dc) and (σ ∞), followed Arrhenius law behavior. Furthermore, activation energy values for each relaxation process were determined, establishing a linear correlation between activation energy values related to relaxation time (τ σ) and both conductivities (σ dc) and (σ∞). These results confirm the origin of bulk relaxations and demonstrate a strong link between relaxation and conduction mechanisms. [ABSTRACT FROM AUTHOR]

The extract of Origanum elongatum Emb. and Maire (OEE) was used as a corrosion inhibitor for C38 steel in 1N HCl medium, the inhibitory effect was studied by different techniques, weight loss and electrochemical measurements. Weight loss measurements indicate a maximum efficiency of 77.50% at a concentration of 1 g/L at 298 K. The potentiodynamic polarization shows that OEE is a mixed type of inhibitor. Electrical impedance spectroscopy measurements show an increase in charge transfer resistance accompanied by a decrease in double layer capacitance, suggesting that the OEE extract acts by adsorption on the metal surface, the decrease in the double layer is always related to the decrease in the dielectric constant and/or the increase in the thickness of the electrical double layer. Adsorption of active OEE species in 1N HCl on C38 steel follows Langmuir isotherm. A fractionation was performed on the OEE, which resulted in three different fractions. These fractions and the OEE were analysed by infrared spectroscopy, the inhibitory efficiencies of the fractions were tested by the weight loss measurements. [ABSTRACT FROM AUTHOR]

Background: In recent years, antioxidants have become essential in nutrition because of their ability to protect the body against oxidative cell damage that can produce dangerous diseases. Medicinal plants are a major source of many bioactive molecules that act directly on the body. Objective: The main objective of our work is to highlight the antioxidant potential of the essential oil (EO) of Origanum elongatum Emb and Maire (endemic plant of Morocco), determine its composition, and carry out fractionation operations to isolate the molecule (s) responsible for this activity. Materials and Methods: The measurement of the antioxidant activity of the EO is carried out by trapping the free radical 2,2-diphenyl-1-picrylhydrazyl and the composition of the EO is determined using gas chromatography coupled with mass spectrometry. The fractionation of the EO was carried out by various chromatography techniques. Results: The results show that the EO has an interesting antioxidant activity with an EC50in the order of 1.2 in comparison with a reference antioxidant, δ-tocopherol whose EC50is 0.26. The EO of O. elongatum consists of 11 compounds, of which 3 are the majority: carvacrol (60.42%), para-cymene (13.9%), and γ-terpinene (9.4%). Conclusion: Fractionation of the oil made it possible to isolate a purified antioxidant molecule consisting mainly of carvacrol (95%). [ABSTRACT FROM AUTHOR]