Chemical Composition and Biological Activities of Mentha Species

The genus Mentha L. (Lamiaceae) is distributed all over the world and can be found in many environments. Mentha species, one of the world’s oldest and most popular herbs, are widely used in cooking, in cosmetics, and as alternative or complementary therapy, mainly for the treatment of gastrointestinal disorders like flatulence, indigestion, nausea, vomiting, anorexia, and ulcerative colitis. Furthermore, it is well documented that the essential oil and extracts of Mentha species possess antimicrobial, fungicidal, antiviral, insecticidal, and antioxidant properties. The economic importance of mints is also evident; mint oil and its constituents and derivatives are used as flavoring agents throughout the world in food, pharmaceutical, herbal, perfumery, and flavoring industry. To provide a scientific basis for their traditional uses, several studies have been conducted to determine the chemical composition of mints and assess their biological activities. This chapter describes the therapeutic effects and uses of Mentha species and their constituents, particularly essential oils and phenolic compounds; some additional biological activities will also be considered

Phenolics content, antiproliferative and antioxidant activities of Algerian Malva sylvestris

Due to its expected low toxicity to human use, more attention is given worldwide to antioxidants of natural sources. Therefore, the extraction of the total phenolic compounds contained in the leaves of Malva sylvestris and the analysis of the polyphenols, flavonoids and tannins contents were carried out. The antioxidant activity of the hydro-methanolic extract of Malva sylvestris was investigated employing various established in vitro systems including 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, the reduction of hydrogen peroxide and the ferric reducing power assay. The antiproliferative activity of plant extract was tested against three tumor cell lines: MCF-7, Hep2 and WEHI using 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphynyl tetrazolium bromide (MTT) assay. Preliminary screening indicated the presence of substances with large therapeutic values: an important content of polyphenols, flavonoids and tannins was detected in the tested extract. Our data showed that the extract exhibited high antioxidant properties, which were demonstrated by its ability to scavenge 76.11% of DPPH free radicals, and the elimination of 69.97% of hydrogen peroxide at a concentration of 125 µg/ml. In addition, the plant extract showed strong ferric reducing power which was a function of the sample concentration. For the antiproliferative activity, the results demonstrated that the plant extract significantly inhibited tumor cell growth and colony formation in a concentration-dependent manner. The toxicity percentage of extract at 125 µg/ml on MCF-7, Hep2 and WEHI was found in the order of 45.20%, 62.62% and 82.04%, respectively. DOI: http://dx.doi.org/10.5281/zenodo.254591

Statistical modeling of monthly rainfall variability in Soummam watershed of Algeria, between 1967 and 2018

AbstractThe monthly precipitations obtained during 51 years of measurement in 24 stations of Soummam watershed in Algeria were analyzed to describe rainfall trends and aridity state of the area using statistical modeling. The choice of distribution laws was justified by comparing fitting results of different distributions laws used in literature reviews. Hence, the p values proved that Generalized Extreme Value, Weibull (3) and Logistic the distribution law are more adequate to analyze rainfall frequencies in different part of the watershed. The diagnostic given by Q‐Q plot, P‐P plot and survival regression curve showed the period of wetness and dryness in the northeastern and the southwestern part of the watershed, respectively. Moreover, the study given by the De Martonne index explains the consequences of climate change by a new form of aridity in the watershed between 1994 and 2018.Recommendations for Resource Managers The annual rainfall of Soummam watershed has a moderate and irregular rainfall distribution between 1967 and 2018. Using distribution function on monthly rainfall in each bioclimatic floor to analyze the trend of rainfall frequency gives a spatio‐temporal description of climate in the area. Fitting by Kolmogorov‐Smirnov test allows us to choose generalized extreme value, Weibull (3) and Logistic for modeling monthly rainfall variability in each part of the watershed. The diagnostic obtained by P‐P plot, Q‐Q plot and survival regression curve proved a change of aridity in the northeastern and southwestern part of the watershed between 1994 and 2018

In vivo assessment of anti-inflammatory and antioxidant activities of Phlomis crinita polyphenols

The leaves of Phlomis crinita are traditionally used in Algerian medicine for the treatment of pain and inflammatory conditions. In order to find a potential application for this native species, the anti-inflammatory and antioxidant effects were investigated on various in vivo experimental models, and the total phenolic compounds and flavonoid contents were determined. The carrageenan-induced paw edema method was used to evaluate the anti-inflammatory activity of the extract in vivo, while the in vivo antioxidant effect was assessed by estimating oxidative stress parameters (MDA, CAT, and SOD). Phytochemical screening revealed the presence of substances with high therapeutic values. In vivo anti-inflammatory studies show that plant extract has a significant and dose-dependent impact on the inhibition of edema formation. The maximum percentage inhibition value was 87.79% after 4 h at a concentration of 500 mg/kg. Moreover, the administration of the extract significantly enhanced the activities of antioxidant enzymes in the livers of mice. It significantly (p ˂ 0.05) increased CAT and SOD activities and significantly (p ˂ 0.05) decreased the MDA level activity, compared to the control inflammatory group. Our findings support that Phlomis crinita can be considered as a promising source of therapeutic bioactive compounds. DOI: http://dx.doi.org/10.5281/zenodo.786033

Ultrasound as pre-treatment for microwave drying of Myrtus communis fruits: Influence on phenolic compounds and antioxidant activity

Background: Drying constitutes the most common method of food preservation that may degrade nutrients compounds in fruits due to high temperatures and long drying times. Myrtus communis is one of the important aromatic and medicinal species, owing to these reasons, the development of new methods of drying is essential for the preservation and valorization of myrtle fruits. Aims: The aim of the present study was to investigate the effect of ultrasound as a pre-treatment (USP) at 10 min to 90 min in microwave-drying (MD) on the dehydration of myrtle Myrtus communis fruits, on phytochemical content, and on antioxidant activity. Methods: ultrasound drying as pretreatment in microwave drying, extraction yield efficiency and antioxidant activity were measured using radical scavenging assay (DPPH•) and reducing power in addition the PCA analysis was investigated to detect the relationships between variables. Results: The ultrasound pretreatment reduced notably the microwave drying time. A pretreatment of 90 min provided the most rapid drying kinetics (6 min and 5.5 min for 500 w and 700 w respectively) compared to the microwave drying alone (18 min and 11 min for 500 w and 700 w respectively). A higher phytochemical content; 219.90 ± 0.69 mg GAE/g for total phenol content (TPC) was obtained compared to those from MD and conventional drying (CD); 193.79 ± 0.99 mg GAE/g and 148.16 ± 0.95 mg GAE/g for TPC respectively. Indeed, the antioxidant activity tests revealed that ultrasound pretreatment is one of the most efficient methods to preserve the quality and the hydrogen and/or electron-donating ability of antioxidants for neutralizing DPPH radicals (98.63 %) test and reducing ferric ions to ferrous ones. Effectively, the results of PCA analysis show a higher positive correlation between antioxidant activity and flavonoids, anthocyanins, and tannins contents. Conclusions: Ultrasound pretreatment is expected to be a potential alternative to preserve fruit quality during microwave drying because it can reduce drying time at ambient temperatures while preserving natural heat-sensitive nutritive components, flavor, and color

Phenolic composition, in vitro antioxidant effects and tyrosinase inhibitory activity of three Algerian Mentha species: M. spicata (L.), M. pulegium (L.) and M. rotundifolia (L.) Huds (Lamiaceae)

International audienceThe leaves of three Mentha species harvested in Algeria, Mentha spicata L. (MS), Mentha pulegium L. (MP) and Mentha rotundifolia (L.) Huds (MR) were examined for their content in polyphenols and for some activities-linked biological properties these could impart. The contents in total phenolics (TPC) and flavonoids (TFC) were evaluated by the Folin–Ciocalteu and the aluminum chloride methods, respectively. Whereas MS showed the highest TPC (12.0 ± 0.3 mg gallic acid equivalents/g of dry weight), MR had the highest content in TFC (3.3 ± 0.1 mg quercetin equivalents of dry weight). The pharmacological properties of these extracts were evaluated by assessing in vitro their antioxidant and antityrosinase activities. The modulation of mushroom tyrosinase activity was measured by colorimetry of the melanins formed in the presence of tyrosine. MS exhibited the strongest radical scavenging activity (RSA) in all assays: (i) the IC50s values to neutralize the 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) cation radicals (ABTS+) and the 2,2′-diphenyl-1-picrylhydrazyl radicals (DPPH) were 10.3 ± 0.9 and 16.2 ± 0.2 μg/mL, respectively; and (ii) its original electrochemically measured superoxide quenching index value is 188 ± 37 μg/mL (AI50). MR however showed the highest tyrosinase inhibitory activity (IC50 = 108 ± 20 μg/mL). A silica gel thin-layer chromatography (TLC) technique revealed the presence of caffeic and rosmarinic acids and diosmin in all extracts. These results were confirmed by high performance liquid chromatography with diode array detection (HPLC/DAD

Phenolic compounds, antioxidant and antibacterial activities of three Ericaceae from Algeria

International audienceHerbs of the Ericaceae family are commonly found in Algeria and used in traditional medicine as antiseptic, diuretic, astringent, depurative, and to treat scalds and wounds. The methanolic extracts of three species, Arbutus unedo L. (A. unedo, leaves), Erica arborea L. (E. arborea, flowered aerial parts), and Erica multiflora L. (E. multiflora, flowered aerial parts), were compared regarding their content in phenolic compounds, their antioxidant, and antibacterial activities. A. unedo harbors the highest content in total phenolics and flavonoids, followed by E. arboreaE. multiflora. The contents in total phenolics and flavonoids showed a correlation with the measured antioxidant (hydrogen-donating) activities; this was particularly the case for flavonoids content. The A. unedo extract showed antibacterial activity against all the tested strains (Staphylococcus aureus ATCC 6538, S. aureus C100459, Escherichia coli ATCC 25922, and Pseudomonas aeruginosa ATCC 9027); however, the E. arborea and E. multiflora extracts showed antibacterial activity only against Gram positive bacteria. Some polyphenols were identified in the three herbs by thin-layer chromatography and high-performance liquid chromatography coupled with diode array and mass spectrometry detection; from these, caffeic acid, p-coumaric acid, naringin, quercetin and kaempferol are reported for the first time in E. multiflora

A global overview of dietary supplements: Regulation, market trends, usage during the COVID-19 Pandemic, and health effects

Over the last 20 years, the use of dietary supplements (DS) has continued to grow in many countries. Due to the public health crisis brought on by the COVID-19 pandemic and amidst fears regarding COVID-19 vaccines and their low supply in many regions of the world, there has been a marked interest in the use of DS as alternative means of protecting against and treating this emerging disease, as well as boosting the immune system and minimizing the risk of inflammation. Despite a lack of evidence to suggest their efficacy, a surge in the sales of DS has been reported in many parts of the world. Questions have also been raised about the health effects associated with DS due to their increased use during the health crisis. Numerous scientific studies have demonstrated their beneficial properties as well as some adverse and even toxic effects. In addition, given the current global interest in this issue, a review is needed to establish the status of dietary supplements before and during the health crisis. The aim of this review is to summarize the current evidence on the impact of dietary supplements on the incidence of the COVID-19 pandemic, as well as their regulation and associated market trends. First, we provide an overview of DS, including a comprehensive review of the legislative and regulatory aspects of DS in the USA, China, the EU, and Algeria. Second, we describe the prevalence of the most commonly consumed DS and their efficacy as a prophylactic modality in the era of COVID-19. Additionally, we examine the structure and size of the DS market in the countries that predominantly produce and import them, its global market trend, and the impact of the COVID-19 pandemic on market growth. Finally, in this review, we also discuss the profile of DS users.info:eu-repo/semantics/publishedVersio