Effect of drying methods on yield, chemical composition and bioactivities of essential oil obtained from Moroccan Mentha pulegium L

Unlocking the combined action of Mentha pulegium L. essential oil and Thym honey: In vitro pharmacological activities, molecular docking, and in vivo anti-inflammatory effect

Mentha pulegium L., a plant widely embraced for its therapeutic properties by populations worldwide, including Morocco, has long been recognized for its potential in treating various ailments. This study aims to comprehensively evaluate the antioxidant, anti-inflammatory, and dermatoprotective properties of essential oil derived from M. pulegium, and thyme honey as well as their combined effects. To unravel the chemical composition, a rigorous GC-MS analysis was conducted. Subsequently, we examined their antioxidant potential through three distinct assays: DPPH●, hydrogen peroxide assay, and xanthine oxidase assay. The anti-inflammatory properties were scrutinized through both in vitro and in vivo experiments. Simultaneously, the dermatoprotective efficacy was investigated in vitro by evaluating tyrosinase inhibition. Our findings revealed that pulegone constitutes the predominant compound in M. pulegium essential oil (MPEO), constituting a remarkable 74.82 % of the composition. Significantly, when the essential oil was combined with thym honey, it exhibited superior anti-inflammatory and dermatoprotective effects across all in vivo and in vitro tests. Moreover, our in silico molecular docking analysis hinted at the potential role of cyclohexanone, 3-methyl, an element found in the MPEO, in contributing to the observed outcomes. While this study has unveiled promising results regarding the combined in vitro, in vivo and in silico biological activities of the essential oil and honey, it is imperative to delve further into the underlying mechanisms through additional experimentation and alternative experimental methods. Understanding these mechanisms in greater detail will not only enhance our comprehension of the therapeutic potential but also pave the way for the development of innovative treatments and applications rooted in the synergy of these natural compounds. Furthermore, it would be advantageous to test different possible combinations using experimental design model. Moreover, it would be better to test the effect of single compounds of MPEO to clearly elucidate their efficiency. MPEO alone or combined with thyme honey may be a useful for the development of novel biopharmaceuticals.

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.

Chemistry behind Quality-Emission of Volatile Enantiomers from Mentha spp. Plant Tissue in Relationship to Odor Sensory Quality

The quality of food, considering increasing consumer demands and competition among producers, is a highly important issue. Quality concerns are also applicable to the odor quality of herbs and spices (HSs). Meanwhile, HSs commonly are graded based on their essential oils (EOs) content and analysis; but does the instrumental analysis really provide general information about the HSs sensory quality? Three chemotypes of Mentha spp. were used in the present study. From samples diversified by convective drying at different temperatures, EOs were hydrodistillated and analyzed by enantioselective GC-MS; moreover, the source plant material's volatile profile was analyzed by the HS-SPME technique. The instrumental analysis was confronted with the results of the sensory panel. Changes in enantiomeric composition were observed during the drying process, although no clear correlations or trends could be found for individual chiral components. Furthermore, even with significant differences in particular volatiles' contribution to plants' EOs and their volatile profiles, judges were not able to match the sample EOs and plant samples with sufficient effectiveness (~40%). Based on those results, we suggest that volatile enantiomeric distribution does not have an actual influence on odor quality and that the sensory analysis should not be replaced with instrumental analysis, which cannot predict general sensory quality.

Drying temperatures affect the qualitative-quantitative variation of aromatic profiling in Anethum graveolens L. ecotypes as an industrial-medicinal-vegetable plant

Introduction

There are several factors that affect the quality and quantity of active ingredients and essential oil (EO) content, including pre and postharvest practices such as drying conditions. One of the most important factors in drying is temperature and then selective drying temperature (DT). In general, DT has a direct effect on the aromatic properties of Anethum graveolens.

Methods

On this basis, the present study was conducted to evaluate the effects of different DTs on the aroma profile of A. graveolens ecotypes.

Results and discussion

The results showed that different DTs, ecotypes, and their interaction significantly affect EO content and composition. The highest EO yield was obtained from the Parsabad ecotype (1.86%) followed by the Ardabil ecotype (1.4%), both at 40° C. More than 60 EO compounds were identified, mainly monoterpenes and sesquiterpenes, highlighting α-Phellandrene, Germacrene D, and Dill apiole as major components in all treatments. Besides α-Phellandrene, the major EO compounds at shad drying (ShD) were β-Phellandrene and p-Cymene, while plant parts dried at 40° C showed l-Limonene and Limonene as the main constituents, and Dill apiole was detected in greater amounts in the samples dried at 60 °C. To determine the appropriate DT, simple and factorial based-ANOVA together multivariate analysis demonstrated significant differences in the compounds produced under different DTs. The results indicated that more EO compounds, mainly monoterpenes, were extracted at ShD than other DTs. On the other hand, the content and composition of sesquiterpenes increased significantly when DT was increased to 60 °C. From the genetic backgrounds point of view, the Parsabad ecotype (with 12 similar compounds) and Esfahan ecotype (with 10 similar compounds) were the most suitable ecotypes under all DTs in terms of EO compounds. Accordingly, the present study would help various industries to optimize specific DT(s) to obtain special EO compound(s) from different A. graveolens ecotypes based on commercial requirements.

The combined effect of essential oils on wood physico-chemical properties and their antiadhesive activity against mold fungi: application of mixture design methodology

In the heritage field, the microbial adhesion on wood, and consequently the formation of biofilm led to inestimable losses of historical and cultural monuments. Thereby, this study aimed to examine the combined effect of Thymus vulgaris, Myrtus communis, and Mentha pulegium essential oils on wood surface physico-chemical properties, and to elaborate the optimal mixture using the mixture design approach coupled to the contact angle method. It was found that both wood hydrophobicity and electron donor character increased significantly after treatment using an optimal mixture containing 57% and 43% of M. pulegium and M. communis essential oils, respectively. The theoretical and experimental fungal adhesion on untreated and treated wood were also investigated. The results showed that the adhesion was favorable on untreated wood and reduced using the optimal mixture. Moreover, the experimental data demonstrated that the same mixture exhibited an antiadhesive efficacy effect with a reduction of 36-75% in adhesion.

Changes in the essential oil content and composition of pelargonium graveolens l’hér with different drying methods

In this study, the effect of various drying methods (fresh plant, shade-drying, sun-drying, and oven-drying at 30 and 60 °C) on the essential oil (EO) composition of rose-scented geranium were determined. Essential oil samples were extracted by hydrodistillation and analyzed by GC and GC-MS systems. The highest EO contents were obtained in the fresh plant (1.98%), followed by shade-drying (1.34 %) and oven-drying at 30 °C (1.20 %). The main components were citronellol (23.99-39.87%), geraniol (4.15-17.09%), menthone (4.48-8.34%), linalool (1.96-7.42%), β-caryophyllene (2.63-4.32%), geranyl tiglate (0.99-4.52%), citronellyl butyrate (0.53-5.31%) and cis-rose oxide (0.71-3.15%). The drying methods showed a marked impact on the constituents of the EO samples. The results demonstrated that drying the aerial parts of fresh geranium, and shade-drying and oven-drying at 30 °C were the best optimal methods to obtain the highest oil yield, and citronellol, geraniol, and linalool contents in the oil.

Effects of Pennyroyal (Mentha pulegium L.) Supplementation on production performance, egg quality traits, and biochemical parameters of blood and egg in laying hens at later stages of the production period

BACKGROUND

According to the promising outcomes acquired in recent studies that focused on using natural feed additives in animal nutrition, poultry nutritionists have also been interested in investigating these medicinal herbs' effects on poultry performance and egg characteristics. Pennyroyal (Mentha pulegium L.), a natural source of antioxidant, antimicrobial, anti-inflammatory, etc. compounds, is recommended as a potential alternative for antibiotics, with similar benefits and no adverse effects on animal health or their products. Considerable effects have been reported on laying hens' performance and their eggs' internal and external traits by pennyroyal inclusion in their diets.

OBJECTIVES

Due to the different results reported by pennyroyal inclusion in laying hens' diets in recent limited studies, this study was designed to reinvestigate the impacts of pennyroyal (Mentha pulegium L.) supplementation (PS) on productive performance, egg quality traits, and biochemical compounds in blood and egg yolk in aged laying hens. The findings of this experiment may help for a better understanding of PS impacts on desired parameters, along with improving aged laying hens' performance.

MATERIALS AND METHODS

A total of 144 Leghorn (Hyline-W36 strain) laying hens (53 weeks old) were used to investigate the effects of PS on performance, egg quality, and biochemical parameters of blood and egg yolk in old laying hens. The animals were distributed into three treatment groups; including a control diet (without PS), 0.5%, and 1% PS diets with six replicates and eight birds per replicate.

RESULTS

The results indicated that the egg production rate (except for week eight) and egg mass were significantly reduced by PS in the laying hens' diet during the first four weeks and the total period of the experiment (P<0.05). However, the feed conversion ratio increased by PS (P<0.05). Based on the egg quality trait evaluations (week 4), the yolk percentage, yolk height, and yolk index reduced, while shell-breaking strength represented a significant increase in PS groups (P<0.05). However, shell thickness and albumen percentage reduced and increased by 1% PS, respectively (P<0.05). At week eight, the Haugh unit reduced while the albumen pH increased by PS (P<0.05). The findings revealed a decline in the egg density in 1% PS groups (P<0.05). In the case of serum biochemical parameters, alanine aminotransferase increased, whereas malondialdehyde (MDA) levels reduced in the PS groups (P<0.05). Moreover, the triglyceride levels of both serum and egg yolk (accompanied by the very low-density lipoprotein level of serum) decreased by PS (P<0.05).

CONCLUSIONS

In conclusion, PS reduced serum and egg yolk triglyceride levels, accompanied by serum MDA, along with reducing production performance.

Allelopathic Properties of Lamiaceae Species: Prospects and Challenges to Use in Agriculture

Herbicide resistance due to the increasing reliance on herbicides is a near-term challenge for the world’s agriculture. This has led to a desire to develop new herbicides with a novel mode of action, to address resistance in weed species. Lamiaceae, a large dicotyledonous plant family, is very well known for the multitudinous pharmacological and toxicological properties of its member species. Moreover, many species of this family are significant for their allelopathic activity in natural and laboratory settings. Thus, plants in Lamiaceae have the potential to be sources of alternative herbicides. However, gaps in our knowledge need to be addressed prior to adopting these allelopathic activities in agriculture. Therefore, we review the existing state of knowledge about the Lamiaceae family, the reported allelopathic properties of plant extracts, and their isolated allelochemicals under laboratory, greenhouse, and field conditions. In addition, we offer a perspective on existing challenges and future opportunities for adopting the allelopathic properties of Lamiaceae plant species for green agriculture.

Analysis of Volatiles of Rose Pepper Fruits by GC/MS: Drying Kinetics, Essential Oil Yield, and External Color Analysis

Condiments and culinary supplements are subjected to long-term storage and may undergo physical, chemical, and biological changes that can influence their quality. Thus, the objective of the present study was to analyze the drying kinetics of rose pepper (Schinus terebinthifolius Raddi) fruits in an oven with forced air circulation at different temperatures, namely, 45, 55, 65, and 75°C, and determine the effective diffusion coefficient and activation energy using different mathematical models. Furthermore, the effects of the different drying temperatures were analyzed for external color parameters and yield of essential oil contents by gas chromatography coupled to a mass spectrometer. Of the ten models used for fitting, Thompson’s model was one with the best fitting to represent the drying of rose pepper fruits. The diffusion coefficient increases with the elevation of drying air temperature, described by the Arrhenius equation, with activation energy of 53.579 kJ·mol−1. The color of the fruits decreased in lightness (L ${}^{\ast }$ ) with the increase in temperature. Of the thirty-eight terpenes identified, α-pinene and cis-ocimene were the most abundant, with the overall highest yield being found at a drying temperature of 45°C.

Investigation of Chemical Compositions and Biological Activities of Mentha suaveolens L. from Saudi Arabia

Mentha is an aromatic plant used since antiquity for its pharmaceutical virtues. The climate of Saudi Arabia favors the growth of aromatic plants including Mentha suaveolens L. The aim of this study is to analyze the volatile oils of different parts of fresh and dried Mentha suaveolens L. grown in Saudi Arabia (Aljouf area) using Gas Chromatography/Mass Spectrometry (GC/MS) and Gas Chromatography Flame Ionization Detector (GC/FID) techniques, to recognize the effect of drying on chemical composition, then to evaluate the antioxidant and antifungal activities of different extracts. In total, 118 compounds were identified via GC/MS and GC/FID, in which carvone is the main volatile constituent (stems, leaves, whole plant 45–64%). This investigation deduces that Mentha belonged to the carvone chemotype. Then, the analysis of non-volatile constituents of fresh and dried Mentha was performed by HPLC. The main phenolic compound of fresh and dried Mentha for different parts was rosmarinic acid (ranging from 28,002.5 to 6558 µg/g). The ethanolic extract of fresh stem showed the highest antifungal activity (53% inhibition) compared with miconazole (60% inhibition) but the ethanoic extract of dry stem showed no activity. Additionally, all ethanolic extracts, whether for fresh or dry Mentha, have antioxidant activity more than 90% while the antioxidant activity of whole plant volatile oil is equal to 53.33%. This research shows that M. suaveolens L. could be applied to manufacture natural antioxidants, antifungal, and flavoring agents.

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.

Impact of drying methods on the yield and chemistry of Origanum vulgare L. essential oil

Oregano (Origanum vulgare L.) is mainly cultivated, both as fresh and dried herb, for several purposes, such as ailments, drugs, and spices. To evaluate the influence of some drying methods on the chemical composition of the essential oil of oregano, its aerial parts were dehydrated by convective drying techniques (shade, static oven), microwave-assisted heating (three different treatments) and osmotic treatment. The oils were analyzed by GC-FID and GC-MS. The highest essential oil yield was achieved from microwave and shade drying methods. In total, 39 components were found, with carvacrol (ranging from 56.2 to 81.4%) being the main constituent; other compounds present in lower amounts were p-cymene (1.6-17.7%), γ-terpinene (0.8-14.2%), α-pinene (0.1-2.1%), thymol methyl ether (0.4-1.8%) and thimoquinone (0.5-3.5%). The essential oil yields varied among the different treatments as well as the relative compositions. The percentages of p-cymene, γ-terpinene and α-pinene decreased significantly in the dried sample compared with the fresh sample; on the other hand, carvacrol, isoborneol and linalool increased significantly in the dried materials. The choice of the drying method for obtaining the essential oil therefore appears crucial not only in relation to the higher yield but also and above all in reference to the percentage presence of components that can direct the essential oil toward an appropriate use.

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).

Investigation of the chemical properties of Mentha pulegium essential oil and its application in Ocimum basilicum seed mucilage edible coating for extending the quality and shelf life of veal stored in refrigerator (4°C)

Nowadays, the tendency toward the application of natural preservatives to extent the shelf life of food products has grown. The purpose of the present research was to evaluate the effect of the basil seed mucilage (BSM)-based edible coating containing different concentrations of Mentha pulegium essential oil (MPEO) on the shelf life of the veal stored at refrigerator temperature. Firstly, the chemical composition and functional groups of MPEO were detected through gas chromatography-mass spectrometry (GC-MS) and Fourier transform infrared spectroscopy (FTIR). Then, the BSM-based edible coatings containing 0%, 0.5%, 1%, 1.5%, and 2% MPEO were prepared, and the veal samples were coated with them. The physicochemical, microbial, and sensory properties of the samples were investigated during the 9-day storage period at 4°C. Twenty-five compounds were detected in MPEO with limonene being the major one (28.44%). The results revealed that the lightness, hardness, and moisture content of the samples decreased during storage. The coating containing the essential oil could properly restrain the rise in pH, peroxide value (PV), and thiobarbituric acid value (TBA). Based on microbial analyses, the shelf life of the coated sample without the essential oil and those containing 0.5%, 1%, 1.5%, and 2% of the essential oil were, respectively, extended up to 3, 6, 9, 9, and 9 days relative to the control. Moreover, the coating containing the essential oil produced no unfavorable effect on the sensory properties of the meat samples. In conclusion, the BSM-based edible coating containing different concentrations of MPEO can be applied as a natural preservative to enhance the resistance of meat products against microbial spoilage and fat oxidation.

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.

A comparative study: Influence of various drying methods on essential oil components and biological properties of Stachys lavandulifolia

The genus Stachys is a member of the Lamiaceae family. These are important medicinal plants which grow all over the world and are known for their flavoring and therapeutic effects and Stachys lavandulifolia is an endemic species of Iran. To acquire high-quality essential oil (EO), drying technique was implemented which is an essential part of this process. The present study designed to evaluate the influences of different drying techniques (fresh sample, shade, sunlight, freeze-drying, microwave, and oven-drying (40, 60, and 80°C) on EO yield and composition of S. lavandulifolia. The results indicated that the maximum EO yield was obtained by the shade-drying method. The main compounds found in the fresh samples were spathulenol, myrcene, β-pinene, δ-cadinene, and α-muurolol, while spathulenol, cyrene, δ-cadinene, p-cymene, decane, α-terpinene, β-pinene, and intermedeol were found to be the dominant compounds in the dry samples. Drying techniques were found to have a significant impact on the values of the main compositions, for example, monoterpene hydrocarbons such as α-pinene, β-pinene, myrcene, and β-phellandrene were significantly reduced by microwave drying, oven-drying (40, 60, and 80°C), and sunlight-drying methods. Drying techniques increased the antioxidant activity of S. lavandulifolia EOs especially those acquired by freeze-drying with the half-maximal inhibitory concentration (IC50) values 101.8 ± 0.8 mg/ml in DPPH assay and 315.2 ± 2.1 mg/ml in decreasing power assay. As a result, shade-, sun-, and oven-drying (40°C) were found to be the most important techniques for attaining maximum yields of EO.

An overview on ethnobotanico-pharmacological studies carried out in Morocco, from 1991 to 2015: Systematic review (part 1)

ETHNOPHARMACOLOGICAL RELEVANCE

The full bibliometric records of data retrieved from ethnobotanical field studies carried out in Morocco (1991-2015) was quali-quantitatively analysed. Despite the importance of traditional medicinal uses in Morocco, any comments about the methodologies and approaches adopted by reviewed studies have been undertaken. Include more data about the importance of traditional medicinal uses in Morocco.

AIM OF THE STUDY

Three key points were targeted in this review: (i) to contribute to original compilation of medicinal plants traditionally used by people at whole Morocco, by gathering and documenting the current status of these ancestral medical practices, (ii) to provide a novel insight into the relationship between local and biomedical disease concepts in Moroccan society, taking into account health-related beliefs, and their influences on medicinal plant uses, (iii) to figurout the weaknesses and the strengths of the conceptual approches and methods adopted by researchers in ethnobotanical field works.

MATERIALS AND METHODS

With the help of a computerized database querying, we conducted an extensive literature search respecting our integration criteria. We performed this bibliographic research by using the following search engines available over the Web: Google Scholar, PUBMED, Sciencedirect, Current Content Connect, SCOPUS, SPRINGER LINK, GLOBAL PLANTS, Cochrane Library and SCIRUS. The scientific names listed in the present paper have been validated according to the "The Plant List" and the African Plants Database in order to standardize ethnobotanical data on an international level. For the analysis of data gathered, quali-quantitative analyses have been performed.

RESULTS

A total of 905 medicinal plant species belonging to 116 families and 726 genera have been selected from 63 published articles. The dominant families were ASTERACEAE (111 species) followed by the FABACEAE (77 species), LAMIACEAE (75 species) and APIACEAE (46 species). The plant species listed are used to cure several public ailments. The digestive ailments represented the most important category (494 species) followed by dermatological diseases (407 species), diabetes (315 species) and urinary diseases (277 species). We assigned the importance of the plant species by several measures (including Frequency Cited (FC), Number of Uses (NU), Number of Respondents (NR) and Index of Performance (IP). The ICF (Informant Consensus Factor) calculated was important in all categories of diseases averaging 47%.

CONCLUSION

The results obtained, which cover the whole country, delineate the profile of rich wealth of indigenous knowledge on traditional uses of medicinal plants heald by Moroccan society. The total number of 905 plant species listed in this paper, are currently being utilized as medicines and the number is expected to grow as infrastructure allows greater access to unexplored parts of the country. Furthermore, the know how, regarding the plants used, is consistent because the ICF has recorded important values for most diseases treated. Furthermore, in the present paper, we suggested, for authors, some useful recommendations for ethnobotanical field works such as the respect of ethnobotanical standards including checklist of plants with international data base, the deposited voucher specimens, sampling and collection methods.

Characterization, activities, and ethnobotanical uses of Mentha species in Morocco

This work is a summary of the characterization, activities, and ethnobotanical surveys about aromatic and medicinal plants belonging to the genus Mentha in Morocco. The Mentha species investigated are Mentha pulegium, Mentha spicata, Mentha viridis, Mentha suaveolens, Mentha longifolia, Mentha gattefossei, Mentha rotundifolia, and Mentha vulgare, with M. pulegium being the most studied species. M. spicata and M. viridis are poorly explored even though they are daily consumed by Moroccans in tea infusions. The elucidated factors affecting the composition of Mentha essential oils are fertilization, drying conditions, mechanical impedance, NaCl stress, and Gamma irradiation. Investigation of the activities of the Mentha species showed that the main interest was dedicated to addressing the antibacterial effect towards gram+ and gram- bacteria. Essential oils of Mentha species exhibited antifungal, antiviral, antioxidant, insecticidal, licidal, niticidal, allelopathic, antidiabetic, derma-protective, and anticorrosive activities. The ethnobotanical surveys revealed that Mentha species are used in seven regions: Tafilalet, High Atlas, Fez-Boulemane, Taounat, Oujda, Ouazzane, and Rabat. By calculating the Jaccard index, the highest degree of similarity was found between Tafilalet, Rabat, and Oujda regions. The wide use of the Mentha species in Morocco highlights the high ethnobotanical value of the genus.