Chemical composition of Mentha pulegium and Rosmarinus officinalis essential oils and their antileishmanial, antibacterial and antioxidant activities

Mentha pulegium L. and Salvia officinalis L. Bioactive Compounds: Focus on Their Application in Agriculture and Food Packaging

Plants are a valuable source of diverse natural active compounds with distinct biological characteristics and mechanisms. Considering plant extracts and phytochemicals have biological action both in vitro and in vivo, plants are being used as alternative sources in agriculture and food industry. Mentha pulegium L. and Salvia officinalis L. from the Lamiaceae family are some of the most popular and widely utilized medicinal plants due to their bioactive compounds such as essential oils (EOs) and phenolics, which have powerful antioxidant and antimicrobial characteristics. It is evident that these plants have also a variety of applications due to their various components and concentrations. This study aimed to provide an overview on the two species' composition and biological activities to review the applications of their crude extracts and EOs in agriculture as natural pesticides to protect different cultures and in food industry to produce biobased food packaging.

Comparative Evaluation of Different Mint Species Based on Their In Vitro Antioxidant and Antibacterial Effect

In our research six different mint species (peppermint, spearmint (five different chemotypes), Horse mint, mojito mint, apple mint (two different chemotypes), bergamot mint) have been evaluated by referring to their chemical (essential oil (EO) content and composition) and in vitro biological (antibacterial, antioxidant effect) characteristics. The EO amount of the analyzed mint populations varied between 1.99 and 3.61 mL/100 g d.w. Altogether, 98 volatile compounds have been detected in the oils. Antibacterial effects (inhibition zones, MIC, IC50 and MBC) were evaluated against Escherichia coli, Salmonella enterica, Bacillus cereus and Staphylococcus aureus. The best antibacterial effect was given by a carvacrol-thymol chemotype spearmint population (inhibition zone: 18.00-20.00 mm, MIC: 0.06 v/v%, IC50: 0.01-0.03 v/v%, MBC: 0.06, >2.00 v/v%). The least effective oil in the case of Gram-negative bacteria was bergamot mint (inhibition zone: 7.67-8.67 mm, MIC: 2.00, >2.00 v/v%, IC50: 0.11-0.25 v/v%, MBC: 2.00, >2.00 v/v%), while in the case of Gram-positive bacteria, oils containing dihydrocarvone as the main compound possessed the weakest antibacterial effect (inhibition zone: 9.00-10.00 mm, MIC: 1.00-2.00 v/v%, IC50: 0.22-0.37 v/v%, MBC: >2.00 v/v%). Interestingly, none of the oils could kill B. cereus in the applied concentrations.

Recent progress in the source, extraction, activity mechanism and encapsulation of bioactive essential oils

There is growing concern about the potential risks posed by synthetic additives in industrial products, such as foods, cosmetics, agrochemicals, and personal care products. Many plant-derived essential oils (EOs) have been shown to exhibit excellent antibacterial, antifungal, antiviral, and antioxidant activities, and may therefore be used as natural preservatives in these applications. However, most EOs have relatively low water solubility and are prone to chemical degradation during storage. The degradation products of EOs can be toxic and may not be able to fully exert their biological activity, which limits their application. Typically, these challenges can be overcome by encapsulating the essential oil in an appropriate colloid delivery system. This article begins by reviewing the sources, extraction, and activity mechanisms of EOs, and then highlights plant-based encapsulation technologies that can be used to enhance their efficacy. Finally, the potential applications of plant essential oil encapsulation system are discussed.

Chemical Composition, Antioxidant Activity, and Multivariate Analysis of Four Moroccan Essential Oils: Mentha piperita, Mentha pulegium, Thymus serpyllum, and Thymus zygis

Background: Food chemical antioxidants have demonstrated protective effects against reactive oxygen species and free radicals, but present in excess, harmful consequences might occur on health. Therefore, replacing these synthetic additives with nontoxic natural antioxidants is crucial. Objective: The current study examined aroma profile, antioxidant activity, and multivariate analysis of Mentha piperita, Mentha pulegium, Thymus serpyllum, and Thymus zygis essential oils from Morocco. Methods: GC-MS analysis was carried out to determine the chemical composition of the four oils, and their antioxidant activity was evaluated with 2,2-diphenyl-1-picrylhydrazyl (DPPH), cation radical (ABTS+), hydrogen peroxide scavenging capacity (H2O2), ferric reducing antioxidant power (FRAP), and total antioxidant capacity (TAC) methods. Results: Isomintlactone (35.55%), pulegone (74.04%), borneol (37.87%), and borneol (30.99%) were the most abundant compounds of M. piperita, M. pulegium, T. serpyllum, and T. zygis EOs. The antioxidant activity of the four EOs was particularly notable, with an IC50 varying between 3.51 ± 0.22 mg/mL and 0.49 ± 0.08 mg/mL by the DPPH method, 1.02 ± 0.21 mg/mL and 0.4 ± 0.7 mg/mL by the ABTS method, and 0.063 ± 0.01 mg/mL and 0.009 ± 0.008 mg/mL by the H2O2 method. For the FRAP technique, the EC50 was between 0.42 ± 0.02 mg/mL and 0.09 ± 0.01 mg/mL. Finally, the equivalent concentration of ascorbic acid ranged between 10.42 ± 0.03 mg AAs/mL for M. piperita and 7.25 ± 0.19 mg AAs/mL for T. serpyllum. As determined by multivariate analysis, antioxidant activities through the DPPH, ABTS, TAC, and FRAP were mainly influenced the major compounds of M. pulegium and M. piperita EOs. However, the H2O2 method showed a stronger positive correlation with major compounds of T. zygis EO. Conclusion: The EOs derived from M. piperita, M. pulegium, T. serpyllum, and T. zygis species might be exploited as a natural source for antioxidant activity.

Biofilm Inhibition Activity of Fennel Honey, Fennel Essential Oil and Their Combination

The eradication of bacterial biofilms remains a persistent challenge in medicine, particularly because an increasing number of biofilms exhibit resistance to conventional antibiotics. This underscores the importance of searching for novel compounds that present antibacterial and biofilm inhibition activity. Various types of honey and essential oil were proven to be effective against a number of biofilm-forming bacterial strains. The current study demonstrated the effectiveness of the relatively unexplored fennel honey (FH), fennel essential oil (FEO), and their combination against biofilm-forming bacterial strains Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus, and Escherichia coli, with a series of in vitro experiments. The authenticity of FH and FEO was checked with light microscopy and gas chromatography-mass spectrometry, respectively. Minimum inhibitory concentrations were determined using the microdilution method, and antibiofilm activity was assessed with crystal violet assay. Structural changes in bacterial cells and biofilms, induced by the treatments, were monitored with scanning electron microscopy. FEO and FH inhibited the biofilm formation of each bacterial strain, with FEO being more effective compared to FH. Their combination was the most effective, with inhibitory rates ranging between 87 and 92%, depending on the bacterial strain. The most sensitive bacterium was E. coli, while P. aeruginosa was the most resistant. These results provide justification for the combined use of honey and essential oil to suppress bacterial biofilms and can serve as a starting point to develop an effective surface disinfectant with natural ingredients.

Chemical composition and biological activities of nine essential oils obtained from Algerian plants

The essential oils (EOs) from nine species (Artemisia campestris, A. herba-alba, Juniperus foetidissima, Laurus nobilis, Mentha pulegium, M. spicata, Rosmarinus officinalis, Salvia officinalis, and Thymus vulgaris) of the Algerian flora have been hydrodistilled, analysed, and tested for their antioxidant and antiproliferative properties. A. campestris EO showed a higher content of terpene hydrocarbons; A. herba-alba EO was mainly rich in their oxygenated derivatives. Sesquiterpenes were the most abundant compounds in J. foetidissima EO, while oxygenated monoterpenes and phenylpropanoids prevailed in L. nobilis EO. The other EOs were rich in oxygenated monoterpenes, with quality-quantitative differences. T. vulgaris and L. nobilis performed better in all the antioxidant assays, respectively with IC50 values ranging from 0.0002 and 0.0012 mg/mL in the CUPRAC assay to 2.83 and 3.50 mg/mL in the FRAP assay. T. vulgaris was also the only EO exhibiting an antiproliferative activity towards the human breast (MCF-7) and lung (A549) cancer cell lines.

Is Camphor the Future in Supporting Therapy for Skin Infections?

The aim of this review is to present the potential application of camphor-a bicyclic monoterpene ketone-in the prevention of skin infections. Skin diseases represent a heterogeneous group of disorders characterized by prolonged symptoms that significantly diminish the quality of life. They affect the dermis, the epidermis, and even subcutaneous tissue. They very often have a bacterial or fungal background. Therapy for dermatological skin disorders is difficult and long-term. Therefore, it is important to find a compound, preferably of natural origin, that (i) prevents the initiation of this infection and (ii) supports the skin's repair process. Based on its documented anti-inflammatory, antibacterial, antifungal, anti-acne, anesthetic, strengthening, and warming properties, camphor can be used as a preventative measure in dermatological infectious diseases and as a component in medical and cosmetic products. This work discusses the structure and physicochemical properties of camphor, its occurrence, and methods of obtaining it from natural sources as well as through chemical synthesis. The use of camphor in industrial preparations is also presented. Additionally, after a detailed review of the literature, the metabolism of camphor, its interactions with other medicinal substances, and its antimicrobial properties against bacteria and fungi involved in skin diseases are discussed with regard to their resistance.

Chemical Composition and Antimicrobial Activity of Essential Oils and Hydrosols from Oregano, Sage and Pennyroyal against Oral Pathogens

In this study, the chemical composition of essential oils (EOs) extracted from Origanum vulgare ssp. hirtum Lamiaceae, (oregano), Salvia officinalis Lamiaceae (sage), Mentha pulegium Lamiaceae (pennyroyal), and respective hydrosols (HSs) has been investigated by Gas Chromatography–Mass Spectrometry (GC-MS). The antimicrobial activity was assessed against two oral pathogens: Gram-positive bacterium Streptococcus mutans and the fungus Candida albicans by determination of Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal/Fungicidal concentration (MBC/MFC). Three-fold diluted solutions were dispensed into each well of a 96-well microtiter plate and, after incubation, MIC was determined by visual monitoring. The MBC/MFC was determined by transferring a small quantity of sample contained in each replicate well of the microtiter plates to appropriate culture media using a microplate replicator. The EOs of the tested herbs showed antimicrobial properties, especially the EO oil of O. vulgare, which exerted the highest antimicrobial activity. HSs of S. officinalis and M. pulegium exerted no antimicrobial activity, in contrast to oregano HS, which displayed strong antimicrobial activity. In all cases, a higher number of compounds were detected in EOs than in the corresponding HSs. The major compounds of sage EO were detected to be α-thujone (25.1%), 1,8-cineole (15.8%) and β-pinene (10.0%), while the HS was characterized by the presence of 1,8-cineole (32.6%), borneol (22.6%) and α-thujone (22.4%). Pennyroyal EO and HS consists mainly of pulegone (62.1 and 50.6%, respectively). Carvacrol was the major component present in EO (63%) and HS (97.3%) of oregano, probably contributing to the antimicrobial activity. Further research is needed in order to elucidate the antimicrobial mechanisms of specific compounds present in essential oils and hydrosols of Lamiaceae grown in Greece against oral pathogens.

Overview of Ethnobotanical-Pharmacological Studies Carried Out on Medicinal Plants from the Serra da Estrela Natural Park: Focus on Their Antidiabetic Potential

The Serra da Estrela Natural Park (NPSE) in Portugal stands out as a well-preserved region abundant in medicinal plants, particularly known for their pharmaceutical applications in diabetes prevention and treatment. This comprehensive review explores these plants' botanical diversity, traditional uses, pharmacological applications, and chemical composition. The NPSE boast a rich diversity with 138 medicinal plants across 55 families identified as traditionally and pharmacologically used against diabetes globally. Notably, the Asteraceae and Lamiaceae families are prevalent in antidiabetic applications. In vitro studies have revealed their significant inhibition of carbohydrate-metabolizing enzymes, and certain plant co-products regulate genes involved in carbohydrate metabolism and insulin secretion. In vivo trials have demonstrated antidiabetic effects, including glycaemia regulation, insulin secretion, antioxidant activity, and lipid profile modulation. Medicinal plants in NPSE exhibit various activities beyond antidiabetic, such as antioxidant, anti-inflammatory, antibacterial, anti-cancer, and more. Chemical analyses have identified over fifty compounds like phenolic acids, flavonoids, terpenoids, and polysaccharides responsible for their efficacy against diabetes. These findings underscore the potential of NPSE medicinal plants as antidiabetic candidates, urging further research to develop effective plant-based antidiabetic drugs, beverages, and supplements.

Mentha Pulegium: A Plant with Several Medicinal Properties

The species Mentha Pulegium L. (M. pulegium L.) belongs to the family Lamiaceae, native to Europe, North Africa, and the Middle East, and the genus Mentha. It has been traditionally used in food, cosmetics, and medicines. It is a perennial, fragrant, well-liked, herbaceous plant that can grow up to half a meter tall. It is extensively used as a food flavoring, particularly for Moroccan traditional drinks. Chewing mint and M. pulegium, a relaxing and refreshing plant, can be used to treat hiccups and act as an anticonvulsant and nerve relaxant. Pennyroyal leaves that have been crushed have a pungent, spearmint-like scent. Pennyroyal is used to make herbal teas, which, while not proven to be harmful to healthy adults in small doses, are not recommended due to their liver toxicity. Infants and children can die if they consume it. Pennyroyal leaves, both fresh and dried, are particularly effective at repelling insects. Pennyroyal essential oil should never be taken internally because it is highly toxic, even in small doses, it can be fatal. This plant is used in traditional Moroccan medicine to treat a wide range of conditions, including influenza, rheumatism, migraine, infertility, ulcer, pain, gastrointestinal problems, fever, diabetes, obesity, mental and cardiac disorders, constipation, respiratory ailments, and cough. M. pulegium is a great candidate for contemporary therapeutic usage since it contains a wide variety of biologically active compounds, including terpenoids, flavonoids, alkaloids, tannins, and saponins in all its parts. Among the different parts used are the whole plant, the aerial part, the stem, and the leaves. More interestingly, the entire plant contains a variety of compounds including Pulegone, Isomenthone, Carvone, Menthofuran, Menthol, 1,8-Cineole, Piperitone, Piperitenone, Neomenthol, -humulene, and 3-octanol. Eriocitrin, Hesperidin, Narirutin, Luteolin, Isorhoifolin, Galic acid, and Rosmarinic acid are found in the leaves. p-hydroxybenzoic acid, Ferulic acid, Caffeic acid, Vanillic acid, Syringic acid, Protocatechuic acid, Cinnamic acid, Phloretic acid, o-coumaric acid, p-coumaric acid, Catechin, Epicatechin, Chrysin, Quercetin, Naringenin, Carvacrol are all found in the areal part. Alterporriol G, Atropisomer, Alterporriol H, Altersolanol K, Altersolanol L, Stemphypyrone, 6-O-methylalaternin, Macrosporin, Altersolanol A, Alterporriol E, Alterporriol D, Alterporriol A, Alterporriol B, and Altersolanol J are also found in the stem of fungus. Pulegone, Piperitone, p-Menthane-1,2,3- triol, β-elemenene, guanine (cis-), Carvacrol acetate, and Phenyl ethyl alcohol are all components of this plant's essential oils. Moreover, the study also sought to investigate and document all currently available evidence and information on the nutritional composition and therapeutic uses of this plant ornamental. Its pharmacological applications include antimicrobial, antioxidant, antihypertensive, antidiabetic, anti-inflammatory, antiproliferative, antifungal, anticancer, burn wound healing, antispasmodic, and hepatotoxicity. Finally, toxicological studies have revealed that while low doses of extracts of the plant M. pulegium are not toxic, however, its essential oils of it are extremely toxic. In order to evaluate future research needs and investigate its pharmacological applications through clinical trials, the current assessment focuses on the distribution, chemical composition, biological activities, and primary uses of the plant.

Moroccan Antihypertensive Plants and their Mechanisms of Action

BACKGROUND

The use of herbal remedies, medicinal plants, and their derivatives for the treatment and control of hypertension is well-known and widespread throughout Morocco.

AIMS

The aim of the study was to review the antihypertensive and vasorelaxant medicinal plants of the Moroccan pharmacopeia.

OBJECTIVE

To date, no review on Moroccan medicinal plants exhibiting antihypertensive effects has been performed, and their mechanism of action has not been specified. The objective of this review was to collect, analyze, and critically assess published publications on experimental and clinical research that explored the blood pressure-reducing abilities of Moroccan medicinal plant extracts.

MATERIALS AND METHODS

This study collected, processed, and critically analyzed published studies related to experimental and clinical research that investigated Moroccan herbal derivatives' blood pressure-lowering abilities using a number of scientific databases, including ScienceDirect, Scopus, PubMed, Google Scholar, and others. Plantlist.org was used to validate the right plant names.

RESULTS

The results revealed 22 species of Moroccan medicinal plants belonging to 13 different groups with recognized antihypertensive properties. The species were abundant in a variety of chemical elements. Asteraceae (08 species), Lamiaceae (3 species), Apiaceae (2 species), and 1 species each from the following families: Parmeliaceae, Fabaceae, Cistaceae, Malvaceae, Polygonaceae, Brassicaceae, Myrtaceae, Rutaceae, Amaranthaceae, Rosaceae, and Lauraceae were the most frequently mentioned families for their antihypertensive properties. The most used parts were the leaves and the aerial parts. The two main methods of preparation among Moroccans were decoction and infusion. This study demonstrated the known antihypertensive and vasorelaxant properties of Moroccan medicinal plants in vivo and in vitro, as well as their mechanisms of action. Interestingly, phytochemicals can operate on blood vessels directly via a vasorelaxant impact involving a range of signaling cascades or indirectly by blocking or activating multiple systems, such as an angiotensin-converting enzyme (ACE), renin-angiotensin system (RAS), or diuretic activity.

CONCLUSION

The review of the available data reveals that more work needs to be done to examine all the Moroccan medicinal plants that have been suggested as antihypertensive in published ethnopharmacological surveys. A review of the literature in this area reveals that methodologies of the experimental study need to be standardized, and purified molecules need to be studied. In addition, mechanistic investigations, when they exist, are generally incomplete. In contrast, only a few advanced clinical investigations have been conducted. However, all studies fail to determine the efficacy/safety ratio.

Optimization and antifungal efficacy against brown rot fungi of combined Salvia rosmarinus and Cedrus atlantica essential oils encapsulated in Gum Arabic

The stability, sensitivity, and volatility of essential oils are some of their most serious limitations, and nanoencapsulation has been considered one of the most effective techniques for solving these problems. This research aimed to investigate the incorporation of Salvia rosmarinus Speen and Cedrus atlantica Manetti (MEO) essential oil mixture in Gum Arabic (GA) and to evaluate nanoencapsulation's ability to promote antifungal activity against two brown rot fungi responsible for wood decay Gloeophyllum trabeum and Poria placenta. The optimization of encapsulation efficiency was performed using response surface methodology (RSM) with two parameters: solid-to-solid (MEO/GA ratio) and solid-to-liquid (MEO/ethanol). The recovered powder characterization was followed by various techniques using a scanning electron microscope (SEM), X-ray diffractometry (XRD), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), and thermo-gravimetric analysis (TGA). The optimal nanoencapsulating conditions obtained from RSM were ratios of MEO/GA of 1:10 (w/w) and MEO/ethanol of 10% (v/v), which provided the greatest encapsulation efficiency (87%). The results of SEM, XRD, DLS, FTIR, and TGA showed that the encapsulation of MEO using GA modified particle form and molecular structure and increased thermal stability. An antifungal activity assay indicated that an effective concentration of MEO had an inhibitory effect on brown rot fungi. It had 50% of the maximal effect (EC50) value of 5.15 ± 0.88 µg/mL and 12.63 ± 0.65 µg/mL for G. trabeum and P. placenta, respectively. Therefore, this product has a great potential as a natural wood preservative for sustainable construction and green building.

Optimisation of Three Essential Oils against Salmonella spp. and Escherichia coli by Mixture Designa

The aim of this work is to optimise the antibacterial activity of essential oils (EOs) from Eucalyptus camaldulensis (ECEO), Mentha pulegium (MPEO) and Rosmarinus officinalis (ROEO) plants against Salmonella spp. and Escherichia coli. The qualitative antimicrobial effect was assessed using the disc diffusion method, the broth microdilution method was used to determine the minimum inhibitory concentrations (MIC). Polynomial models were created using an augmented centroid simplex mixture design to highlight the synergy of EOs. The results show a significant antibacterial effect of ECEO and MPEO against both bacterial strains, with inhibition zones (IZs) of 13 and 12 mm respectively against E. coli, and 13 and 11 mm against Salmonella spp. The latter strain showed a MIC of 0.625 % (v : v) by the ECEO, while E. coli exhibited a MIC of 0.0781 % (v : v). The binary combinations of essential oils display a synergistic effect, the proportions of the optimum EOs in the mixture giving the lowest MICm were of the order of 50.51 % ECEO and 49.49 % ROEO against Salmonella spp. and around 50 % MPEO and 50 % ECEO against E. coli. These results indicate the effectiveness of binary combinations EOs against resistant bacterial strains and suggest their importance in bacterial infections treatment.

Caccinia macranthera Brand var. macranthera: Phytochemical analysis, phytotoxicity and antimicrobial investigations of essential oils with concomitant in silico molecular docking based on OPLS force-field

This study was conducted to extract the essential oils (EOs) of Caccinia macranthera identify their phytochemicals, evaluate their phytotoxicity, antimicrobial activity and enzyme inhibition effects using in silico molecular docking technique. EOs of aerial parts, seeds, and roots of C. macranthera were extracted and analyzed via Gas chromatography-Mass Spectrometry. The antibacterial activity of EOs were determined on nine microorganisms via disk diffusion and microbroth dilution assays. In addition, the allelopathic properties of EOs were investigated by calculating the IC50s for inhibition of germination, seedling length and seedling weight growth of Cuscuta campestris seeds. In order to assess the possible inhibitory effect of major components of C. macranthera EOs on enzymes inhibiting germination and plant growth, molecular docking was employed against the glutamine synthetase (GS), acetohydroxyacid synthetase (AHAS), and 4-hydroxyphenyl pyruvate dioxygenase (HPPD) enzymes. The main compounds of EOs from aerial parts, seeds, and roots EOs were dihydrocarveol (29.5%), Trimethyl-2-Pentadecanone (13.6%), and Palmitic acid (16.8%), respectively. The maximum antibacterial effect was related to the aerial parts EO against Staphylococcus epidermidis. Phytotoxicity analysis exhibited a concentration-dependent increase (p ≤ 0.05) activity. The aerial parts EO demonstrated a substantial allelopathy effect, with IC50 values of 0.22 ± 0.026, 0.39 ± 0.021, and 0.20 ± 0.025 mg/mL, respectively, on inhibitory germination, seedling length and seedling weight growth of Cuscuta campestris seeds. Molecular docking analyzes showed that Oleic acid was suitable for dynamic stabilization of HPPD (-6.552 kJ/mol) and GS (-7.265 kJ/mol) and Eupatoriochromene had the inhibitory potential against AHAS, with docking score of -4.189 kJ/mol. The current research demonstrated that C. macranthera EOs from its aerial parts have an acceptable phytotoxic activity against Cuscuta campestris weed. The major components of EOs, Oleic acid and Eupatoriochromene, presented the strongest binding with HPPD, GS, and AHAS active sites causing disturbance in germination, photosynthesis and weed growth suggesting it as a natural herbicide for controlling the weeds.

Peppermint essential oil and its nano-emulsion: Potential against aflatoxigenic fungus Aspergillus flavus in food and feed

A facultative parasite called Aspergillus flavus contaminates several important food crops before and after harvest. In addition, the pathogen that causes aspergillosis infections in humans and animals is opportunistic. Aflatoxin, a secondary metabolite produced by Aspergillus flavus, is also carcinogenic and mutagenic, endangering human and animal health and affecting global food security. Peppermint essential oils and plant-derived natural products have recently shown promise in combating A. flavus infestations and aflatoxin contamination. This review discusses the antifungal and anti-aflatoxigenic properties of peppermint essential oils. It then discusses how peppermint essential oils affect the growth of A. flavus and the biosynthesis of aflatoxins. Several cause physical, chemical, or biochemical changes to the cell wall, cell membrane, mitochondria, and associated metabolic enzymes and genes. Finally, the prospects for using peppermint essential oils and natural plant-derived chemicals to develop novel antifungal agents and protect foods are highlighted. In addition to reducing the risk of aspergillosis infection, this review highlights the significant potential of plant-derived natural products and peppermint essential oils to protect food and feed from aflatoxin contamination and A. flavus infestation.

Combination of Chemically-Characterized Essential Oils from Eucalyptus polybractea, Ormenis mixta, and Lavandula burnatii: Optimization of a New Complete Antibacterial Formulation Using Simplex-Centroid Mixture Design

This study aims to identify the volatile profile of three essential oils obtained from Eucalyptus polybractea cryptonifera (EPEO), Ormenis mixta (OMEO), and Lavandula burnatii briquet (LBEO) and to examine their combined antibacterial activity that affords the optimal inhibitory ability against S. aureus and E. coli using simplex-centroid mixture design and checkerboard assay. Essential oils (EOs) were isolated by hydrodistillation and characterized using gas chromatography-mass spectrometry (GC-MS) and gas chromatography coupled with flame-ionization detector (GC-FID). The antibacterial activity was performed using disc diffusion and microdilution assays. The chemical analysis revealed that 1,8-cineole (23.75%), p-cymene (22.47%), and α-pinene (11.20%) and p-menthane-1,8-diol (18.19%), α-pinene (10.81%), and D-germacrene (9.17%) were the main components detected in E. polybractea and O. mixta EOs, respectively. However, L. burnatii EO was mainly represented by linalool (24.40%) and linalyl acetate (18.68%). The EPEO, LBEO, and OMEO had a strong antibacterial effect on S. aureus with minimal inhibitory concentrations (MICs) values ranging from 0.25 to 0.5% (v/v). Furthermore, the combination of 1/2048 MICEPEO + 1/4 MICLBEO showed a synergistic antibacterial effect on S. aureus with a FIC index of 0.25, while the formulation of 1/4 MICEPEO + 1/4 MICOMEO demonstrated an antibacterial synergistic activity on E. coli with a FIC index of 0.5. Moreover, the simplex-centroid mixture design reported that the most effective combinations on E. coli and S. aureus correspond to 32%/28%/40% and 35%/30%/35% of E. polybractea, O. mixta, and L. burnatii, respectively. Presented information highlights the action of antibacterial formulations of these EOs and suggests their potential applications as alternatives to commercialized drugs to contract the development of bacteria causing serious infections and food deterioration.

Simultaneous Hydrodistillation of Cedrus atlantica Manetti and Salvia rosmarinus Spenn: Optimization of Anti-Wood-Decay Fungal Activity Using Mixture Design Methodology

Chemical fungicides are often harmful to people and the environment because of their toxicity. The wood protection industry places a high priority on replacing them with natural products. Therefore, this investigation focused on developing a formulation of a binary combination of Salvia rosmarinus Spenn and Cedrus atlantica Manetti obtained by Simultaneous hydrodistillation to protect the wood from decay using a mixture design methodology. The chemical composition of essential oil was identified by gas chromatography coupled with mass spectrometry (GC/MS), and their anti-wood-decay fungal activity was assessed using the macrodilution method against four fungi responsible for wood decay: Coniophora puteana, Coriolus versicolor, Gloeophyllum trabeum, and Poria placenta. The results of GC/MS identified myrtenal as a new component appearing in all binary combinations. The optimum anti-wood-decay fungal activity was observed in a combination of 60% S. rosmarinus and 40% C. atlantica essential oils, providing an effective concentration for 50% of maximal effect (EC50) value of 9.91 ± 1.91 and 9.28 ± 1.55 μg/mL for C. puteana and C. versicolor, respectively. The highest anti-wood-decay fungal activity for G. trabeum and P. placenta was found in the combination of 55% of S. rosmarinus and 45% of C. atlantica essential oils, with EC50 values of 11.48 ± 3.73 and 22.619 ± 3.79 μg/mL, respectively. Combined simultaneous hydrodistillation improved the antifungal effect of these essential oils. These results could be used to improve antifungal activity and protect wood against wood-decay fungi.

An Insight into In Vitro Antioxidant, Antimicrobial, Cytotoxic, and Apoptosis Induction Potential of Mangiferin, a Bioactive Compound Derived from Mangifera indica

Due to their low cost, toxicity, and health risks, medicinal plants have come to be seen as useful products and sources of biologically active compounds. Mangifera indica L., a medicinal plant with a long history, has a high bioactive metabolites content. Mangiferin (C₁₉H₁₈O₁₁) is primary isolated from M. indica's leaves, which has many pharmacological benefits. In this investigation, ultrasonic-assisted extraction with ethanol as the extraction solvent was applied to obtain mangiferin from a local type of M. indica leaves. HPLC was performed after a dichloromethane-ethyl acetate liquid-liquid fractionation method. Further, UV-vis, FTIR, and NMR spectroscopy were utilized to elucidate the structure. Interestingly, purified mangiferin displayed promising antimicrobial efficacy against a diverse variety of fungal and bacterial pathogens with MICs of 1.95-62.5 and 1.95-31.25 µg/mL, respectively. Time-kill patterns also showed that mangiferin had both bactericidal and fungicidal action. Furthermore, it exhibited strong radical dosage-dependent scavenging activity (IC₅₀ = 17.6 μg/mL) compared to vitamin C (Vc, IC₅₀ = 11.9 μg/mL), suggesting it could be developed into a viable antioxidant agent. To our delight, the IC₅₀ values of mangiferin for the MCF-7 and HeLa cell lines were 41.2 and 44.7 μg/mL, respectively, from MTT cell viability testing, and it was less harmful when tested against the noncancerous cell line. Notably, it significantly induced cell apoptosis in MCF-7 cells by 62.2-83.4% using annexin V-FITC/PI labeling. Hence, our findings suggest that mangiferin can be used in the medical industry to create therapeutic interventions and medication delivery systems for society.

Rosemary (Rosmarinus officinalis L.) Glycolic Extract Protects Liver Mitochondria from Oxidative Damage and Prevents Acetaminophen-Induced Hepatotoxicity

Rosmarinus officinalis L. (rosemary) is an aromatic culinary herb. Native to the Mediterranean region, it is currently cultivated worldwide. In addition to its use as a condiment in food preparation and in teas, rosemary has been widely employed in folk medicine and cosmetics. Several beneficial effects have been described for rosemary, including antimicrobial and antioxidant activities. Here, we investigated the mechanisms accounting for the antioxidant activity of the glycolic extract of R. officinalis (Ro) in isolated rat liver mitochondria (RLM) under oxidative stress conditions. We also investigated its protective effect against acetaminophen-induced hepatotoxicity in vivo. A crude extract was obtained by fractionated percolation, using propylene glycol as a solvent due to its polarity and cosmeceutical compatibility. The quantification of substances with recognized antioxidant action revealed the presence of phenols and flavonoids. Dereplication studies carried out through LC-MS/MS and GC-MS, supported by The Global Natural Product Social Molecular Networking (GNPS) platform, annotated several phenolic compounds, confirming the previous observation. In accordance, Ro decreased the production of reactive oxygen species (ROS) elicited by Fe2+ or t-BOOH and inhibited the lipid peroxidation of mitochondrial membranes in a concentration-dependent manner in RLM. Such an effect was also observed in liposomes as membrane models. Ro also prevented the oxidation of mitochondrial protein thiol groups and reduced glutathione (GSH). In model systems, Ro exhibited a potent scavenger activity toward 2,2′-diphenyl-1-picrylhydrazyl (DPPH) radicals and superoxide anions. It also demonstrated an Fe2+ chelating activity. Moreover, Ro did not exhibit cytotoxicity or dissipate the mitochondrial membrane potential (∆Ψ) in rat liver fibroblasts (BRL3A cells). To evaluate whether such antioxidant protective activity observed in vitro could also be achieved in vivo, a well-established model of hepatotoxicity induced by acute exposure to acetaminophen (AAP) was used. This model depletes GSH and promotes oxidative-stress-mediated tissue damage. The treatment of rats with 0.05% Ro, administered intraperitoneally for four days, resulted in inhibition of AAP-induced lipid peroxidation of the liver and the prevention of hepatotoxicity, maintaining alanine and aspartate aminotransferase (ALT/AST) levels equal to those of the normal, non-treated rats. Together, these findings highlight the potent antioxidant activity of rosemary, which is able to protect mitochondria from oxidative damage in vitro, and effects such as the antioxidant and hepatoprotective effects observed in vivo.

Nutritionally rich biochemical profile in essential oil of various Mentha species and their antimicrobial activities

The Mentha species of family Lamiaceae are famous for their flavor and are commercially used in many food products worldwide. They are widely used to cure digestive problems as well as a natural source of antioxidants and antimicrobials. In this report, the essential oils (EOs) of five Mentha species, namely Mentha citrata, Mentha x piperita, Mentha pulegium, Mentha spicata, and Mentha suaveolens were extracted and their chemical diversity was investigated through gas chromatography-mass spectroscopy (GC-MS). The differential doses (5, 10, and 15 µl) of EOs were tested for antimicrobial potential against two gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis), five gram-negative bacteria (Escherichia coli, Pseudomonas aeroginosa, Salmonella typhi, Proteus mirabilis and Klebsiella pneumoniae) and a fungal strain (Candida albicans). The GC-MS results revealed the major components in the EOs were Carvone, Linalool, Hotrienol, Menthol, Isopulegone, Furanone, Piperitone, and Thymol. Moreover, the higher dose (15 µl) of EOs of M. citrata inhibited the growth of S. typhi and C. albicans (35.8 ± 2.4 and 35.2 ± 2.5 mm), M. x piperita inhibited E. coli, B. subtilis, and C. albicans (28.5 ± 3.5, 26.1 ± 2.1, and 25.4 ± 1.1 mm), M. pulegium inhibited K. pneumoniae, B. subtilis, and C. albicans (26.8 ± 1.8, 24.2 ± 2.2, and 25.3 ± 0.9 mm), M. spicata significantly inhibited S. typhi and B. subtilis (35.7 ± 2.7 and 36.3 ± 2.1 mm), and M. suaveolens inhibited K. pneumoniae, C. albicans, and S. typhi (30.8 ± 1.9, 26.9 ± 1.1, and 20.1 ± 0.8 mm) respectively. This study concluded that the EOs of M. citrata was effective against S. typhi and C. albicans. The M. x piperita exhibited strong activities against E. coli, B. subtilis, and C. albicans. Furthermore, the M. pulegium strongly inhibited the growth of K. pneumoniae and C. albicans. The EO of M. spicata was more potent against S. typhi and B. subtilis, while the M. suaveolens was comparatively more effective against S. typhi, K. pneumoniae, and C. albicans. These EOs offer a natural source of antimicrobial agents with high commercial values and social acceptance and could be scale up by food and pharmaceutical industries to control pathogenic diseases.

Anti-Trypanosomatidae Activity of Essential Oils and Their Main Components from Selected Medicinal Plants

Kinetoplastida is a group of flagellated protozoa characterized by the presence of a kinetoplast, a structure which is part of a large mitochondria and contains DNA. Parasites of this group include genera such as Leishmania, that cause disease in humans and animals, and Phytomonas, that are capable of infecting plants. Due to the lack of treatments, the low efficacy, or the high toxicity of the employed therapeutic agents there is a need to seek potential alternative treatments. In the present work, the antiparasitic activity on Leishmania infantum and Phytomonas davidi of 23 essential oils (EOs) from plants of the Lamiaceae and Asteraceae families, extracted by hydrodistillation (HD) at laboratory scale and steam distillation (SD) in a pilot plant, were evaluated. The chemical compositions of the EOs were determined by gas chromatography-mass spectrometry. Additionally, the cytotoxic activity on mammalian cells of the major components from the most active EOs was evaluated, and their anti-Phytomonas and anti-Leishmania effects analyzed. L. infantum was more sensitive to the EOs than P. davidi. The EOs with the best anti-kinetoplastid activity were S. montana, T. vulgaris, M. suaveolens, and L. luisieri. Steam distillation increased the linalyl acetate, β-caryophyllene, and trans-α-necrodyl acetate contents of the EOs, and decreased the amount of borneol and 1,8 cineol. The major active components of the EOs were tested, with thymol being the strongest anti-Phytomonas compound followed by carvacrol. Our study identified potential treatments against kinetoplastids.

Antileishmanial Screening, Cytotoxicity, and Chemical Composition of Essential Oils: A Special Focus on Piper callosum Essential Oil

Leishmania amazonensis is the etiological agent of tegumentary leishmaniasis, a disease characterized by the emergence of cutaneous and mucocutaneous ulcerated lesions that can evolve into severe destruction of skin tissue. Treatment of the disease is often accompanied by high toxicity and variable efficacy. Essential oils stand out for having diverse pharmacological properties. Here, we screened a panel of fourteen essential oils for their anti-L. amazonensis activity, cytotoxicity, and chemical profile. Lippia sidoides (LSEO) and Piper callosum (PCEO) oils displayed the best anti-promastigote and anti-amastigote activities with IC₅₀ of 31 and 21 μg/ml, respectively. PCEO was the safest oil with a desirable selectivity index >10. In addition, PCEO showed no cytotoxicity against the VERO line and erythrocytes. PCEO-treated amastigotes displayed mitochondrial membrane depolarization and high levels of intracellular ROS. Safrole (54.72 %) was the main component of PCEO. The results described here highlight the use of essential oils to combat tegumentary leishmaniasis.

Chemical Composition, Antibacterial and Antioxidant Activities of Essential Oil from Centipeda minima

This study elucidated the chemical composition of essential oil from Centipeda minima (EOCM) and its antibacterial and antioxidant activities with two chemical monomers thymol and carvacrol. The main chemical composition of EOCM, analyzed by GC-MS, were trans-chrysanthenyl acetate, thymol, aromadendrene and β-caryophyllene. In the screening of antibacterial activity against S. aureus, two monomers with antibacterial activity were obtained: thymol and carvacrol. The MIC of EOCM, thymol and carvacrol were 0.625 mg/mL, 0.156 mg/mL and 0.156 mg/mL, respectively. The experimental results were shown that three drugs could inhibit the growth of S. aureus and inhibit the formation of biofilm by changing the permeability of cell membrane and interfering with the metabolic activities in bacteria. The scavenging effects of the three drugs on DPPH radical and hydroxyl radical showed that the antioxidant effect of the three drugs was EOCM > carvacrol > thymol.

Determination of Chemical Composition and Investigation of Biological Activities of Ocimum basilicum L

This study aimed to determine the chemical composition of the essential oils (EOs) of Ocimum basilicum L., as well as to evaluate the antibacterial, antidiabetic, dermatoprotective, and anti-inflammatory properties, and the EOs and aqueous extracts of O. basilicum. The antibacterial activity was evaluated against bacterial strains, Gram-positive and Gram-negative, using the well diffusion and microdilution methods, whereas the antidiabetic activity was assessed in vitro using two enzymes involved in carbohydrate digestion, α-amylase and α-glucosidase. On the other hand, the dermatoprotective and anti-inflammatory activities were studied by testing tyrosinase and lipoxygenase inhibition activity, respectively. The results showed that the chemical composition of O. basilicum EO (OBEO) is dominated by methyl chavicol (86%) and trans-anethol (8%). OBEO exhibited significant antibacterial effects against Gram-negative and Gram-positive strains, demonstrated by considerable diameters of the inhibition zones and lower MIC and MBC values. In addition, OBEO exhibited significant inhibition of α-amylase (IC50 = 50.51 ± 0.32 μg/mL) and α-glucosidase (IC50 = 39.84 ± 1.2 μg/mL). Concerning the anti-inflammatory activity, OBEO significantly inhibited lipoxygenase activity (IC50 = 18.28 ± 0.03 μg/mL) compared to the aqueous extract (IC50 = 24.8 ± 0.01 μg/mL). Moreover, tyrosinase was considerably inhibited by OBEO (IC50 = 68.58 ± 0.03 μg/mL) compared to the aqueous extract (IC50 = 118.37 ± 0.05 μg/mL). The toxicological investigations revealed the safety of O. basilicum in acute and chronic toxicity. The finding of in silico analysis showed that methyl chavicol and trans-anethole (main compounds of OBEO) validate the pharmacokinetics of these compounds and decipher some antibacterial targets.

Chemical Constituents, Antioxidant, and Enzyme Inhibitory Activities Supported by In-Silico Study of n-Hexane Extract and Essential Oil of Guava Leaves

Psidium guajava (Guava tree) is one of the most widely known species in the family Myrtaceae. The Guava tree has been reported for its potential antioxidant, anti-inflammatory, antimicrobial, and cytotoxic activities. In the current study, the chemical compositions of the n-hexane extract and the essential oil of P. guajava were investigated using the GC/MS analysis, along with an evaluation of their antioxidant potential, and an investigation into the enzyme inhibition of acetylcholinesterase (AChE), butyrylcholinesterase (BchE), tyrosinase, α-amylase, and α-glucosidase. Moreover, molecular docking of the major identified active sites of the target enzymes were investigated. The chemical characterization of the n-hexane extract and essential oil revealed that squalene (9.76%), α-tocopherol (8.53%), and γ-sitosterol (3.90%) are the major compounds in the n-hexane extract. In contrast, the major constituents of the essential oil are D-limonene (36.68%) and viridiflorol (9.68%). The n-hexane extract showed more antioxidant potential in the cupric reducing antioxidant capacity (CUPRAC), the ferric reducing power (FRAP), and the metal chelating ability (MCA) assays, equivalent to 70.80 ± 1.46 mg TE/g, 26.01 ± 0.97 mg TE/g, and 24.83 ± 0.35 mg EDTAE/g, respectively. In the phosphomolybdenum (PM) assay, the essential oil showed more antioxidant activity equivalent to 2.58 ± 0.14 mmol TE/g. The essential oil demonstrated a potent BChE and tyrosinase inhibitory ability at 6.85 ± 0.03 mg GALAE/g and 61.70 ± 3.21 mg KAE/g, respectively. The α-amylase, and α-glucosidase inhibitory activity of the n-hexane extract and the essential oil varied from 0.52 to 1.49 mmol ACAE/g. Additionally, the molecular docking study revealed that the major compounds achieved acceptable binding scores upon docking with the tested enzymes. Consequently, the P. guajava n-hexane extract and oil can be used as a promising candidate for the development of novel treatment strategies for oxidative stress, neurodegeneration, and diabetes mellitus diseases.

Mineral contents, antimicrobial profile, acute and chronic toxicity of the aqueous extract of Moroccan Thymus vulgaris in rodents

Moroccan flora is rich in plants used in traditional medicine, but the further scientific investigation is necessary. The aim of the research was to evaluate the nutritional content and antimicrobial activity of Moroccan Thymus vulgaris, as well as its possible acute and chronic toxicological effects on rodents. Inductively coupled plasma atomic emission spectroscopy (ICP-AES) was used to determine the mineral content. The antimicrobial activity was determined using a well-diffusion test, a minimum inhibitory concentration (MIC), and a minimum bactericidal/fungicidal concentration (MBC/MFC) assay. Acute and chronic toxicity studies were conducted in vivo on mice and rats, respectively. Following that, haematological, serum-biochemistry, and histological investigations were performed. Moroccan Thyme was shown to be a source of numerous minerals which are necessary for health promotion. All antimicrobial testing, disc diffusion, MIC, and MBC tests revealed that thyme had potent antibacterial activity against all microorganisms tested. Staphylococcus aureus was the most susceptible bacterium, followed by Salmonella enterica and Escherichia coli. Additionally, thyme exhibited great antifungal efficacy against Candida albicans. The acute toxicity results indicated that the aqueous extract of T. vulgaris is almost non-toxic when taken orally. According to the chronic toxicity study, the extract is generally safe when taken orally over an extended period of time. The biochemical and haematological characteristics of the serum and blood were within acceptable limits, and histological examination revealed no abnormalities. In conclusion, the findings of this investigation, confirm the antimicrobial efficacy of the aqueous extract of Moroccan T. vulgaris and its safety for experimental animals.

Antileishmanial Activities of Medicinal Herbs and Phytochemicals In Vitro and In Vivo: An Update for the Years 2015 to 2021

Leishmaniasis is one of the most neglected tropical diseases that present areal public health problems worldwide. Chemotherapy has several limitations such as toxic side effects, high costs, frequent relapses, the development of resistance, and the requirement for long-term treatment. Effective vaccines or drugs to prevent or cure the disease are not available yet. Therefore, it is important to dissect antileishmanial molecules that present selective efficacy and tolerable safety. Several studies revealed the antileishmanial activity of medicinal plants. Several organic extracts/essential oils and isolated natural compounds have been tested for their antileishmanial activities. Therefore, the aim of this review is to update and summarize the investigations that have been undertaken on the antileishmanial activity of medicinal plants and natural compounds derived, rom plants from January 2015 to December 2021. In this review, 94 plant species distributed in 39 families have been identified with antileishmanial activities. The leaves were the most commonly used plant part (49.5%) followed by stem bark, root, and whole plant (21.9%, 6.6%, and 5.4%, respectively). Other plant parts contributed less (<5%). The activity was reported against amastigotes and/or promastigotes of different species (L. infantum, L. tropica, L. major, L. amazonensis, L. aethiopica, L. donovani, L. braziliensis, L. panamensis, L. guyanensis, and L. mexicana). Most studies (84.2%) were carried out in vitro, and the others (15.8%) were performed in vivo. The IC50 values of 103 plant extracts determined in vitro were in a range of 0.88 µg/mL (polar fraction of dichloromethane extract of Boswellia serrata) to 98 µg/mL (petroleum ether extract of Murraya koenigii). Among the 15 plant extracts studied in vivo, the hydroalcoholic leaf extract of Solanum havanense reduced parasites by 93.6% in cutaneous leishmaniasis. Voacamine extracted from Tabernaemontana divaricata reduced hepatic parasitism by ≈30 times and splenic parasitism by ≈15 times in visceral leishmaniasis. Regarding cytotoxicity, 32.4% of the tested plant extracts against various Leishmania species have a selectivity index higher than 10. For isolated compounds, 49 natural compounds have been reported with anti-Leishmania activities against amastigotes and/or promastigotes of different species (L. infantum, L. major, L. amazonensis, L. donovani and L. braziliensis). The IC50 values were in a range of 0.2 µg/mL (colchicoside against promastigotes of L. major) to 42.4 µg/mL (dehydrodieuginol against promastigotes of L. amazonensis). In conclusion, there are numerous medicinal plants and natural compounds with strong effects (IC50 < 100 µg/mL) against different Leishmania species under in vitro and in vivo conditions with good selectivity indices (SI > 10). These plants and compounds may be promising sources for the development of new drugs against leishmaniasis and should be investigated in randomized clinical trials.

Determination of Chemical Compounds and Investigation of Biological Properties of Matricaria chamomilla Essential Oils, Honey, and Their Mixture

This exploratory investigation aimed to determine the chemical composition and evaluate some biological properties, such as antioxidant, anti-inflammatory, antidiabetic, and antimicrobial activities, of Matricaria chamomilla L. essential oils (EOs). EOs of M. chamomilla were obtained by hydrodistillation and phytochemical screening was performed by gas chromatography-mass spectrophotometry (GC-MS). The antimicrobial activities were tested against different pathogenic strains of microorganisms by using disc diffusion assay, the minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) methods. The antidiabetic activity was performed in vitro using the enzyme inhibition test. The antioxidant activity of EOs was tested using the free radical scavenging ability (DPPH method), ferrous ion chelating (FIC) ability, and β-carotene bleaching assay. The anti-inflammatory effects were tested in vivo using the carrageenan-induced paw edema method and in vitro using the inhibition of the lipoxygenase test. The analysis of the phytochemical composition by GC-MS revealed that camphor (16.42%) was the major compound of EOs, followed by 3-carene (9.95%), β-myrcene (8.01%), and chamazulene (6.54%). MCEO, honey, and their mixture exhibited antioxidant activity against the DPPH assay (IC50 ranging from 533.89 ± 15.05 µg/mL to 1945.38 ± 12.71 µg/mL). The mixture exhibited the best radical scavenging activity, with an IC50 of 533.89 ± 15.05 µg/mL. As antidiabetic effect, EO presented the best values against α-glucosidase (265.57 ± 0.03 μg/mL) and α-amylase (121.44 ± 0.05 μg/mL). The EOs and honey mixture at a dose of 100 mg/kg exhibited a high anti-inflammatory effect, with 63.75% edema inhibition after 3 h. The impact of EOs on the studied species showed an excellent antimicrobial (Staphylococcus aureus ATCC 29213 (22.97 ± 0.16 mm)), antifungal (Aspergillus niger (18.13 ± 0.18 mm)) and anti-yeast (Candida albicans (21.07 ± 0.24 mm) effect against all the tested strains. The results obtained indicate that the EOs of M. chamomilla could be a potential drug target against diabetes, inflammation and microbial infections; however, further investigations to assess their bioactive molecules individually and in combination are greatly required.

Chemical Profiling and Biological Activities of Pelargonium graveolens Essential Oils at Three Different Phenological Stages

The aim of this work was the determination of Pelargonium graveolens (aerial parts) volatile compounds at three developmental stages and the evaluation of their antioxidant, antidiabetic, dermaprotective, anti-inflammatory, and antibacterial effects. The aerial parts of Pelargonium graveolens were collected at three stages, namely the vegetative, beginning, and full flowering. Pelargonium graveolens essential oils were extracted from the dried materials of these aerial parts by hydrodistillation. The volatiles were analyzed by Gas Chromatography-Mass Spectrometry GC-MS, and the antioxidant activity was assessed by DPPH, ABTS, H₂O₂, and FRAP assays. The in vitro antidiabetic effect was evaluated by the inhibition of α-amylase, α-glucosidase, and lipase enzymes, while the antibacterial activity was assessed against six bacterial strains using an agar well diffusion assay and a microdilution method. The main constituents were menthol, menthene, eremophilene, isoborneol, isogeraniol, α-pinene, linalyl acetate, and 3-carene, with quantitative differences at the three phenological stages. The essential oil at the full flowering stage showed the best antioxidant activity, with IC₅₀ values of 83.26 ± 0.01, 116.42 ± 0.07, 132.25 ± 0.11, and 48.67 ± 0.04 μg/mL for DPPH, FRAP, ABTS, and H₂O₂ assays, respectively. This oil also exhibited significant effects against α-amylase (IC₅₀ = 43.33 ± 0.01 μg/mL), α-glucosidase (IC₅₀ = 19.04 ± 0.01 μg/mL), lipase (IC₅₀ = 24.33 ± 0.05 μg/mL), 5-lipoxygenase (IC₅₀ = 39.31 ± 0.01 μg/mL), and tyrosinase (IC₅₀ = 124.49 ± 0.07 μg/mL). The essential oil extracted at the full flowering stage showed the best antibacterial effect against a panel of microorganisms with diameter inhibition zones ranging between 11.00 ± 0.17 mm and 17.30 ± 0.17 mm and MIC values from 0.25% to 2% v/v. Overall, the results presented here suggest that the full flowering stage is the best optimal harvest time of Pelargonium graveolens for food and pharmaceutical applications.

Peppermint essential oil: its phytochemistry, biological activity, pharmacological effect and application

Mentha (also known as peppermint), a genus of plants in the taxonomic family Lamiaceae (mint family), is widely distributed throughout temperate regions of the world. Mentha contains various constituents that are classified as peppermint essential oil (PEO) and non-essential components. PEO, consisting mainly of menthol, menthone, neomenthol and iso-menthone, is a mixture of volatile metabolites with anti-inflammatory, antibacterial, antiviral, scolicidal, immunomodulatory, antitumor, neuroprotective, antifatigue and antioxidant activities. Mounting evidence indicates that PEO may pharmacologically protect gastrointestinal, liver, kidney, skin, respiratory, brain and nervous systems, and exert hypoglycemic and hypolipidemic effects. Clinically, PEO is used for gastrointestinal and dermatological diseases, postoperative adjuvant therapy and other fields. This review aims to address the advances in the extraction and isolation of PEO, its biological activities, pharmacological effects, toxicity and applications, with an emphasis on the efficacy of PEO on burn wounds and psoriasis, providing a comprehensive foundation for research, development and application of PEO in future.

Synergistic Effect of Bioactive Monoterpenes against the Mosquito, Culex pipiens (Diptera: Culicidae)

Mosquitoes represent one of the most important vectors and are responsible for the transmission of many arboviruses that affect human and animal health. The chemical method using synthetic insecticides disturbs the environmental system and promotes the appearance of resistant insect species. Therefore, this study investigated the insecticidal effect of some binary monoterpene combinations (1,8 cineole + α-pinene and carvone + R (+)-pulegone) using a mixture design approach. The fumigant toxicity was evaluated against Culex pipiens female adults using glass jars. The results show that the toxicity varies according to the proportions of each compound. Indeed, Mixture 1 (1,8-cineole + α-pinene) displayed a strong toxic effect (51.00 ± 0.86% after 24 h and 100.00 ± 0.70% after 48 h) when the pure compounds were tested at 0.25/0.75 proportions of 1,8-cineole and α-pinene, respectively. Nevertheless, the equal proportion (0.5/0.5) of carvone and R (+)-pulegone in Mixture 2 exhibited a toxic effect of 54.35 ± 0.75% after 24 h and 89.96 ± 0.14% after 48 h, respectively. For Mixture 1, the maximum area of mortality that the proposed model indicated was obtained between 0/1 and 0.25/0.75, while the maximum area of mortality in the case of Mixture 2 was obtained between 0.25/0.75 and 0.75/0.25. Moreover, the maximum possible values of mortality that could be achieved by the validated model were found to be 51.44% (after 24 h) and 100.24% (after 48 h) for Mixture 1 and 54.67% (after 24 h) and 89.99% (after 48 h) for Mixture 2. It can be said that all purev molecules tested through the binary mixtures acted together, which enhanced the insecticide’s effectiveness. These findings are very promising, as the chemical insecticide (deltamethrin) killed only 19.29 ± 0.01% and 34.05 ± 1.01% of the female adults after 24 h and 48 h, respectively. Thus, the findings of our research could help with the development of botanical insecticides that might contribute to management programs for controlling vectors of important diseases.

Chemometric Investigation and Antimicrobial Activity of Salvia rosmarinus Spenn Essential Oils

To ensure the better production and sustainable management of natural resources, a chemometric investigation was conducted to examine the effect of cooperative and harvesting periods on the crop yields and chemical compositions of Salvia rosmarinus Spenn essential oils in the Oriental region of Morocco. The samples were collected from three cooperatives over nine time periods from January 2018 to April 2019. The chemical composition of Salvia rosmarinus Spenn essential oils was analyzed by gas chromatography coupled with mass spectrometry. The data from this study were processed by multivariate analyses, including principal component analysis (PCA) and hierarchical cluster analysis (HCA). The disc diffusion technique and a determination of the minimal inhibitory concentration were performed to study the antibacterial properties of the oils. Statistical analysis showed that the cooperative and harvest period have a significant effect on yields. The highest yield of essential oil was recorded in April 2019 at cooperative C1. The PCA and the HCA results were divided into two groups: Group A for the summer season and group B for the winter season. The samples collected during summer were characterized by a high amount of 1,8-cineole component and a high yield of essential oil, whereas the samples collected during winter were qualified by a high amount of α-pinene component and a low yield of essential oil. The antibacterial activity of Salvia rosmarinus Spenn essential oils showed that Mycobacterium smegmatis ATCC23857 and Bacillus subtilis ATCC 23857 are the most susceptible strains, stopping growth at 1/500 (v/v). The least susceptible strain is Escherichia coli ATCC25922, with an MIC value corresponding to 1/250 (v/v). The findings of this study could have a positive economic impact on the exploitation of rosemary in the Oriental region, especially during the best harvest periods, as they indicate how to obtain the best yields of oils richest in 1,8-cineole and α-pinene chemotypes.

Insecticidal Effect of Wild-Grown Mentha pulegium and Rosmarinus officinalis Essential Oils and Their Main Monoterpenes against Culex pipiens (Diptera: Culicidae)

The present study investigates the insecticidal effect of plant extract such as Mentha pulegium and Rosmarinus officinalis essential oils and some of their major compounds; these plants are well known for their many biological activities. The fumigant toxicity was evaluated, using glass jars, against female adults of Culex pipiens that constitute a mosquito vector of important diseases such as the West Nile virus. The adulticidal test showed that both essential oils and monoterpenes presented an insecticidal effect better than the chemical insecticide (Deltamethrin). The highest mortality percentages for the two essential oils have occurred at 312.5 µL/L air (between 56.14 ± 1.7% and 97.71 ± 3.03% after 24 h and 48 h of treatment). Moreover, all tested monoterpenes (carvone, R(+)-pulegone, 1,8-cineole, camphor and α-pinene) have produced high mortalities that varied depending on the time of the treatment and the concentrations used. Lethal concentrations (LC50) obtained for the essential oils and the main compounds have also varied according to the exposure time. M. pulegium and R. officinalis essential oil exhibited the lowest LC50 values after 24 h (72.94 and 222.82 µL/L air, respectively) and after 48 h (25.43 and 55.79 µL/L air, respectively) while the pure molecules revealed the lowest LC50 values after 48 h (between 84.96 and 578.84 µL/L air). This finding proves that the two essential oils and their main compounds have an insecticidal potential, which could help to develop natural toxic fumigants that may be used as an eco-friendly alternative in integrated and sustainable vector management.

Machine Learning Analysis of Essential Oils from Cuban Plants: Potential Activity against Protozoa Parasites

Essential oils (EOs) are a mixture of chemical compounds with a long history of use in food, cosmetics, perfumes, agricultural and pharmaceuticals industries. The main object of this study was to find chemical patterns between 45 EOs and antiprotozoal activity (antiplasmodial, antileishmanial and antitrypanosomal), using different machine learning algorithms. In the analyses, 45 samples of EOs were included, using unsupervised Self-Organizing Maps (SOM) and supervised Random Forest (RF) methodologies. In the generated map, the hit rate was higher than 70% and the results demonstrate that it is possible find chemical patterns using a supervised and unsupervised machine learning approach. A total of 20 compounds were identified (19 are terpenes and one sulfur-containing compound), which was compared with literature reports. These models can be used to investigate and screen for bioactivity of EOs that have antiprotozoal activity more effectively and with less time and financial cost.

Lamiaceae Essential Oils, Phytochemical Profile, Antioxidant, and Biological Activities

Medicinal and aromatic plants present important active compounds that have potential for use in food, pharmaceutical, and agriculture industries. In this sense, the present work aimed to conduct a literature review on the potential applications of essential oils from Lamiaceae species. Antioxidant, anti-inflammatory, and antimicrobial activities were evaluated. The importance of this study is demonstrated as a way to theoretically provide information on the use of different plants belonging to the Lamiaceae family, especially with regard to the physical, chemical, and biological properties of its essential oils.

Health Benefits and Pharmacological Properties of Carvone

Carvone is a monoterpene ketone contained in the essential oils of several aromatic and medicinal plants of the Lamiaceae and Asteraceae families. From aromatic plants, this monoterpene is secreted at different concentrations depending on the species, the parts used, and the extraction methods. Currently, pharmacological investigations showed that carvone exhibits multiple pharmacological properties such as antibacterial, antifungal, antiparasitic, antineuraminidase, antioxidant, anti-inflammatory, and anticancer activities. These studies were carried out in vitro and in vivo and involved a great deal of knowledge on the mechanisms of action. Indeed, the antimicrobial effects are related to the action of carvone on the cell membrane and to ultrastructural changes, while the anti-inflammatory, antidiabetic, and anticancer effects involve the action on cellular and molecular targets such as inducing of apoptosis, autophagy, and senescence. With its multiple mechanisms, carvone can be considered as natural compounds to develop therapeutic drugs. However, other investigations regarding its precise mechanisms of action as well as its acute and chronic toxicities are needed to validate its applications. Therefore, this review discusses the principal studies investigating the pharmacological properties of carvone, and the mechanism of action underlying some of these properties. Moreover, further investigations of major pharmacodynamic and pharmacokinetic studies were also suggested.

Antitrypanosomal Activity of Anthriscus Nemorosa Essential Oils and Combinations of Their Main Constituents

This study aimed to investigate the susceptibility of Trypanosoma brucei to the Anthriscus nemorosa essential oils (EOs), isolated compounds from these oils, and artificial mixtures of the isolated compounds in their conventional and nanoencapsulated forms. The chemical composition of the essential oils from the aerial parts and roots of Anthriscus nemorosa, obtained from a wild population growing in central Italy, were analyzed by gas chromatography/mass spectrometry (GC/MS). In both cases, the predominant class of compounds was monoterpene hydrocarbons, which were more abundant in the EOs from the roots (81.5%) than the aerial parts (74.0%). The overall results of this work have shed light on the biological properties of A. nemorosa EO from aerial parts (EC50 = 1.17 μg/mL), farnesene (EC50 = 0.84 μg/mL), and artificial mixtures (Mix 3-5, EC50 in the range of 1.27 to 1.58 μg/mL) as relevant sources of antiprotozoal substances. Furthermore, the pool measurements of ADP (adenosine diphosphate) and NTPs (nucleoside triphosphates) in the cultivated bloodstream form of trypanosomes exposed to different concentrations of EOs showed a disturbed energy metabolism, as indicated by increased pools of ADP in comparison to ATP (adenosine triphosphate) and other NTPs. Ultimately, this study highlights the significant efficacy of A. nemorosa EO to develop long-lasting and effective antiprotozoal formulations, including nanoemulsions.

Chemical Characterization and Antioxidant, Antimicrobial, and Insecticidal Properties of Essential Oil from Mentha pulegium L

The chemical composition and antibacterial, insecticidal, and antioxidant properties of the essential oil from Mentha pulegium L. (M. pulegium) growing in Morocco were investigated in this work. To achieve this goal, the oils were obtained by using hydrodistillation before being characterized by GC-MS. The antibacterial and antifungal activities were conducted against pathogenic strains using the disc diffusion and MICS bioassays. The insecticidal activity was carried out versus C. maculatus using contact and inhalation tests. The antioxidant activity was performed by using DPPH and total antioxidant capacity bioassays. The chemical analysis of the oil showed that 20 compounds were identified, which represented 98.91% of the total oil. In the oil, the main components detected were R-(+)-pulegone (76.35%), carvone (5.84%), dihydrocarvone (5.09%), and octanol-3 (2.25%). The essential oil has moderate-to-strong broad-spectrum antibacterial and antifungal properties; the results showed that B. subtilis was the most sensitive strain to M. pulegium oil, with the largest inhibition diameter (25 ± 0.33). For the antifungal activity, the results obtained indicated that Aspergillus niger was the most sensitive fungal strain to M. pulegium oil with an inhibition percentage up to 100%. Regarding the insecticidal activity, the inhalation test showed a high efficacy (100% mortality), and a lethal concentration of LC₅₀ = 1.41 + 0.48 μL/L air was obtained after 24 hours of exposure. Moreover, the contact test showed that a total reduction in fertility and emergence was obtained with a dose of 20 μL/mL of acetone. Regarding the antioxidant activity, the sample concentration necessary to inhibit 50% of HE radicals (IC₅₀) was 7.659 mg/mL (DPPH) and 583.066 57.05 mg EAA/g EO (TAC).

Essential Oils from Fruit and Vegetables, Aromatic Herbs, and Spices: Composition, Antioxidant, and Antimicrobial Activities

In the field of food preservation, encapsulated Essential Oils (EOs) could be the best non-toxic and eco-friendly tool for food preservative applications substituting the chemicals ones that have several disadvantages for the environment and health. Thirteen commercial EOs from plants, fruits, and vegetables were characterized by GC-MS. The antioxidant activity was measured by DPPH and ABTS techniques. Antimicrobial activity was assessed by agar well-diffusion method and the Minimum Inhibitory Concentration (MIC) by agar dilution method against six bacteria, Candida albicans, and Botrytis cinerea. All the EOs tested have demonstrated antioxidant activity in the range of IC50 0.01-105.32 mg/mL. Between them, cinnamon EOs were the best, followed by oregano and thyme EOs. Fennel EO showed the lowest radical scavenging. MIC values ranged from 0.14 to 9 mg/mL. C. cassia, thyme, and oregano EOs were the most effective against the bacterial species tested, and the yeast C. albicans. On the contrary, citric fruit EOs showed low or no inhibition against most bacterial strains. The percentages of inhibition of mycelia growth of B. cinerea ranged from 3.4 to 98.5%. Thyme, oregano, mint, and fennel EOs showed the highest inhibition.

In Vitro Evaluation of Lavandula angustifolia Essential Oil on Anti-Toxoplasma Activity

The current methods of treating toxoplasmosis have a number of side effects, and these therapies are only effective against the acute stage of the disease. Thus, development of new low toxicity and efficient anti-Toxoplasma drugs is extremely important. Natural products are important sources for screening new drugs; among them, essential oils (EOs) have efficacy in anti-bacterial, anti-inflammatory, anti-insect, and other aspects. In this study, 16 EOs were screened for their anti-T. gondii activity. Lavandula angustifolia essential oil (La EO)was found to have an anti-parasitic effect on T. gondii. The cytotoxicity of La EO was firstly evaluated using the MTT assay on human foreskin fibroblast (HFF) cells, and then the anti-T. gondii activity was evaluated by plaque assay. Finally, the invasion experiment and electron microscope observation were used to study the mechanism of La EO in anti-toxoplasma activity. The results indicated that the CC₅₀ of La EO was 4.48 mg/ml and that La EO had activity against T. gondii and the inhibition was in a dose-dependent manner under safe concentrations. La EO was able to reduce T. gondii invasion, which may be due to its detrimental effect on changes of the morphology of tachyzoites. These findings indicated that La EO could be a potential drug for treating toxoplasmosis.

The Synergistic Effect of Three Essential Oils against Bacteria Responsible for the Development of Lithiasis Infection: An Optimization by the Mixture Design

The present study aimed to determine the chemical composition and the synergistic effect of three plants' essential oils (EOs), Eucalyptus camaldulensis (ECEO), Mentha pulegium (MPEO), and Rosmarinus officinalis (ROEO), against three bacterial strains, Proteus mirabilis, Klebsiella pneumoniae, and Staphylococcus aureus, in order to increase the antimicrobial effectiveness by the use of a low dose of essential oils, consequently decreasing the toxicity and negative impact. For this reason, an augmented simplex-centroid mixture design was used to build polynomial models in order to highlight the synergy between the essential oils against bacterial strains. Antimicrobial effect screening was performed by the disc diffusion method and the minimal inhibitory concentrations (MIC) were also studied. The gas chromatography/mass spectrometry (GC-MS) results show the richness of these essential oils by terpenic compounds, especially 1,8-Cineole and P-Cymene for ECEO, Pulegone for MPEO, and α-Pinene and Camphene for ROEO. Moreover, a significant antibacterial effect has been demonstrated and the best values were revealed by MPEO and ECEO against P. mirabilis and K. pneumoniae, with inhibition zones (IZ) of 25 and 20 mm, respectively, and an MIC of 0.0391% (v:v) against K. pneumoniae. The optimal mixtures showed a synergistic effect of essential oils, and the lowest minimal inhibitory concentrations of the mixtures (MICm) were in the order of 29.38% of MPEO, 45.37% of ECEO, and 25.25% of ROEO against P. mirabilis and in the order of 60.61% of MPEO and 39.39% of ROEO against K. pneumoniae. These results indicate the antibacterial efficacy of the three essential oils combined and suggest their importance in the treatment of urinary tract infections caused by resistant bacterial strains.

Phytochemical Analysis and Study of Antioxidant, Anticandidal, and Antibacterial Activities of Teucrium polium subsp. polium and Micromeria graeca (Lamiaceae) Essential Oils from Northern Morocco

The protection of agricultural crops and the preservation of the organoleptic and health qualities of food products represent a major challenge for the agricultural and agro-food industries. Essential oils have received greater attention as alternatives to replace the control strategies based on pesticides against phytopathogenic bacteria and synthetic compounds in food preservation. The aims of this work were to study the chemical composition of Teucrium polium subsp. polium and Micromeria graeca essential oils and to examine their antioxidant and antimicrobial effects. To carry out this work, the chemical composition of the essential oil was determined using gas chromatography (GC) with the detection feature of mass spectrometry (MS). Subsequently, the antioxidant activity was investigated by DPPH and FRAPS assays. The antimicrobial effect was studied against phytopathogenic and foodborne pathogenic bacteria using the disc and the microdilution methods. Our results showed that GC-MS analysis of EOs allowed the identification of 30 compounds in T. polium EO (TPpEO), while 5 compounds were identified in M. graeca EO (MGEO). TPpEO had as major compounds β-pinene (19.82%) and germacrene D (18.33%), while geranial (36.93%) and z-citral (18.25%) were the main components of MGEO. The most potent activity was obtained from MGEO (IC₅₀ = 189.7 ± 2.62 µg/mL) compared to TPpEO (IC₅₀ = 208.33 ± 3.51 µg/mL. For the FRAP test, the highest reducing power was obtained from 1.32 ± 0.1 mg AAE/g of TPpEO compared to MGEO 0.51 ± 0.13 mg AAE/g of EO. Both EOs exhibited varying degrees of antibacterial activities against all the tested strains with inhibition zones in the range of 9.33 ± 0.57 mm to >65 mm and MIC values from 0.19 to 12.5 mg/mL. However, MGEO exhibits an interesting anticandidal effect with inhibition zone 44.33 ± 0.57 mm. The findings of this research establish the riches of EOs on volatile compounds, their important antioxidant activity, and their antimicrobial effect against the bacteria tested.