Myrtus communisEssential Oil: Chemical Composition and Antimicrobial Activities against Food Spoilage Pathogens

The therapeutic value of Myrtus communis L.: an updated review

Myrtus communis L. (Family: Myrtaceae) is naturally found in the western part of Asia, Southern Europe, and North Africa. It has been reportedly applied in pharmaceutical industry, traditional medicine, cosmetics, spices, and food. Pubmed, Google scholar, Web of Science, and Scopus were utilized to seek out relevant content concerning the therapeutic potential of M. communis. Subsequently, we conducted a review to identity noteworthy updates pertaining to M. communis. Myrtle berries, leaves, seeds, and essential oils are natural sources of several nutrients and bioactive compounds with marked health effects. The chemical analysis showed that M. communis contained oils, alkaloids, flavonoids, phenolics, coumarins, saponosides, tannins, quinines, and anthraquinones. A pharmacological investigation revealed that M. communis possessed anti-inflammatory, analgesic, antimicrobial, antiparasitic, antioxidant, antidiabetic, anticancer, antimutagenic, immunomodulatory, dermatological, cardiovascular, central nervous system, and gastrointestinal protective effects, among numerous other biological effects. This current review focused on the biochemical, pharmacological, therapeutic effects, and various biological activities of different parts of M. communis. It signifies that M. communis is a therapeutic plant with numerous applications in medicine and could be used as a drug isolate based on its safety and effectiveness.

Bioactive Profiling, Antibacterial Efficacy and Computational Modelling of Myrtus Communis Essential Oil (Morocco)

In the context of investigations into molecules of natural origin with biological activities. This study focuses on the development of Myrtus communis L., a medicinal plant found in the mountains of Morocco. The first, an analysis carried out on leaves using the inductively coupled plasma spectrometry technique, showed the almost total absence of heavy metals. Furthermore, we aim to identify the chemical composition of its essential oils by gas chromatography-mass spectrometry (GC/MS) analysis and assess its antibacterial efficacy in vitro and in silico. The average yield of essential oils was 0.9 %±0.06, and GC/MS analysis identified 35 constituents, with myrcene (27,38 %), limonene (16,51 %), α-pinene (7,32 %) being the major compounds. Remarkably, the essential oils displayed considerable antibacterial activity against various tested bacteria, including Escherichia coli (0.7 μL/mL), Escherichia pseudocoloides (2.8 μl/ml), Escherichia vekanda (2.8 μl/ml). Molecular docking has contributed to our understanding of the mechanism of antibacterial action of the main compounds in this essential oil.

Mixture design of α-pinene, α-terpineol, and 1,8-cineole: A multiobjective response followed by chemometric approaches to optimize the antibacterial effect against various bacteria and antioxidant activity

α-Pinene, α-terpineol, and 1,8-cineole are compounds naturally present in essential oils, although their amounts vary from oil to oil. Although several studies have reported their antibacterial and antioxidant effects, there are few reports on the synergistic or antagonistic effects of their combinations. The objective of this study was to investigate the combined antibacterial effect of these three compounds. To our knowledge, this is the first report on the prediction of their optimal combination using the mixture design approach. The experimental antibacterial activity of the α-pinene, α-terpineol, and 1,8-cineole mixtures depended on the proportion of each compound in the mixture and the target strain, with minimum inhibitory concentrations (MIC) ranging from 0.31 to 1.85 mg/mL. Using the increased simplex-centroid mixture design, the mixture containing 0.33% of each molecule proved to be the most effective against Bacillus cereus and had the lowest MIC values. In addition, α-pinene, α-terpineol, and 1,8-cineole showed significant antioxidant activity against 2,2-picryl-1-hydrazyl radical (DPPH), with IC50 values of 24.53 ± 0.05, 65.63 ± 0.71, and 63.58 ± 0.01 μg/mL, respectively. Statistical planning and the development of utility profiles of the substance mixtures can predict the optimal composition that will exhibit the highest antibacterial activity against B. cereus as well as antioxidant properties. Furthermore, the synergistic effect of the mixtures can contribute significantly to their successful use as natural preservatives in various applications.

Salvia officinalis L. and Salvia sclarea Essential Oils: Chemical Composition, Biological Activities and Preservative Effects against Listeria monocytogenes Inoculated into Minced Beef Meat

In this study, Salvia officinalis L. and Salvia sclarea essential oils (EOs) were investigated using gas chromatography-mass spectrometry (GC-MS) to describe their chemical composition. The obtained results show, for both EOs, a profile rich in terpene metabolites, with monoterpenes predominating sesquiterpenes but with significant qualitative and quantitative differences. The main compound found in the Salvia officinalis EO (SOEO) was camphor (19.0%), while in Salvia sclarea EO (SCEO), it was linalyl acetate (59.3%). Subsequently, the in vitro antimicrobial activity of the EOs against eight pathogenic strains was evaluated. The disc diffusion method showed a significant lysis zone against Gram-positive bacteria. The minimum inhibitory concentrations (MICs) ranged from 3.7 mg/mL to 11.2 mg/mL, indicating that each EO has specific antimicrobial activity. Both EOs also showed significant antiradical activity against DPPH radicals and total antioxidant activity. In addition, the preservative effect of SOEO (9.2%) and SCEO (9.2%), alone or in combination, was tested in ground beef, and the inhibitory effect against Listeria monocytogenes inoculated into the raw ground beef during cold storage was evaluated. Although the effect of each individual EO improved the biochemical, microbiological, and sensory parameters of the samples, their combination was more effective and showed complete inhibition of L. monocytogenes after 7 days of storage at 4 °C. The results show that both EOs could be used as safe and natural preservatives in various food and/or pharmaceutical products.

Unveiling the Chemical Profiling Antioxidant and Anti-Inflammatory Activities of Algerian Myrtus communis L. Essential Oils, and Exploring Molecular Docking to Predict the Inhibitory Compounds against Cyclooxygenase-2

Considering the large spectrum of side effects caused by synthetic drugs and the development of natural alternatives utilizing Algerian flora, this study aimed to place a spotlight on the chemical profile and antioxidant and anti-inflammatory activities of Myrtus communis L. essential oils (MCEOs). In this study, essential oils (EOs) were collected via hydro-distillation of the plant's leaves, and a chemical constituent analysis was performed using gas chromatography-mass spectrophotometry (GC-MS). The in vitro antioxidant activity was evaluated using DPPH, ABTS, and hydroxyl radical scavenging tests. The in vitro anti-inflammatory capacity was estimated by studying the antidenaturation effect using bovine serum albumin (BSA) as a protein model. The in vivo anti-inflammatory activity was carried out by utilizing the classical model of carrageenan-induced paw edema in rats, using diclofenac (DCF) as the reference drug. Moreover, the molecular interaction of the compounds obtained from the GC-MS analysis was studied within the binding site of cyclooxygenase-2 (COX-2) using an in silico approach as the confirmatory tool of the in vitro and in vivo experiments. The GC-MS analysis revealed that MCEOs were mainly composed of oxygenated monoterpenes (70.56%), oxygenated sesquiterpenes (3.1%), sesquiterpenes (4.17%), and monoterpenes (8.75%). Furthermore, 1,8-cineole was the major compound (19.05%), followed by cis-geranyl acetate (11.74%), methyl eugenol (5.58%), α-terpineol (4.62%), and β-myrcene (4.40%). MCEOs exhibited remarkable concentration-dependent free radical scavenging activity, with an IC50 of 15.317 ± 0.340 µg/mL, 18.890 ± 2.190 µg/mL, and 31.877 ± 0.742 µg/mL for DPPH, ABTS, and hydroxyl radical, respectively. The significant in vitro anti-inflammatory activity due to the inhibition of BSA denaturation was proportional to the EO concentration, where the highest value was recorded at 100 μg/mL with an approximately 63.35% percentage inhibition and an IC50 of 60.351 ± 5.832 μg/mL. MCEOs showed a good in vivo anti-inflammatory effect by limiting the development of carrageenan-induced paw thickness. The in silico study indicated that, among the 60 compounds identified by the GC-MS analysis, 9 compounds were observed to have a high binding energy to cyclooxygenase-2 as compared to diclofenac. Our study revealed that EOs from Algerian Myrtus communis L. can be considered to be a promising candidate for alleviating many debilitating health problems and may provide new insights in the fields of drug design, agriculture, and the food industry.

Antimicrobial Effects and Antioxidant Activity of Myrtus communis L. Essential Oil in Beef Stored under Different Packaging Conditions

The aim of this study was to assess the antimicrobial effects of myrtle (Myrtus communis L.) essential oil (EO) on pathogenic (E. coli O157:H7 NCTC 12900; Listeria monocytogenes ATCC BAA-679) and spoilage microbiota in beef and determine its minimum inhibitory concentration (MIC) and antioxidant activity. The behavior of LAB, Enterobacteriaceae, Pseudomonas spp., and fungi, as well as total mesophilic (TM) and total psychotropic (TP) counts, in beef samples, was analyzed during storage at 2 and 8 °C in two different packaging systems (aerobiosis and vacuum). Leaves of myrtle were dried, its EO was extracted by hydrodistillation using a Clevenger-type apparatus, and the chemical composition was determined using chromatographical techniques. The major compounds obtained were myrtenyl acetate (15.5%), β-linalool (12.3%), 1,8-cineole (eucalyptol; 9.9%), geranyl acetate (7.4%), limonene (6.2%), α-pinene (4.4%), linalyl o-aminobenzoate (5.8%), α-terpineol (2.7%), and myrtenol (1.2%). Myrtle EO presented a MIC of 25 µL/mL for E. coli O157:H7 NCTC 12900, E. coli, Listeria monocytogenes ATCC BAA-679, Enterobacteriaceae, and E. coli O157:H7 ATCC 35150 and 50µL/mL for Pseudomonas spp. The samples packed in aerobiosis had higher counts of deteriorative microorganisms than samples packed under vacuum, and samples with myrtle EO presented the lowest microbial contents, indicating good antimicrobial activity in beef samples. Myrtle EO is a viable natural alternative to eliminate or reduce the pathogenic and deteriorative microorganisms of meat, preventing their growth and enhancing meat safety.

Mediterranean Plants with Antimicrobial Activity against Staphylococcus aureus, a Meta-Analysis for Green Veterinary Pharmacology Applications

Antimicrobial resistance (AMR) has emerged as a global health crisis, necessitating the search for innovative strategies to combat infectious diseases. The unique biodiversity of Italian flora offers a treasure trove of plant species and their associated phytochemicals, which hold immense potential as a solution to address AMR. By investigating the antimicrobial properties of Italian flora and their phytochemical constituents, this study aims to shed light on the potential of phyto-complexes as a valuable resource for developing novel or supportive antimicrobial agents useful for animal production.

How to Naturally Support the Immune System in Inflammation-Essential Oils as Immune Boosters

Efficient functionality of the immune system is needed to fight against the development of infectious diseases, including, among others, serious recurrent chronic infections. Research has shown that many modern common diseases, such as inflammatory bowel diseases and cardiovascular diseases, e.g., thromboembolism, cancer, obesity, or depression, are connected with inflammatory processes. Therefore, new, good stimulators of the immune system's response are sought. They include synthetic compounds as well as biological preparations such as lipopolysaccharides, enzymes, bacterial metabolites, and secondary metabolites of plants, demonstrating a multidirectional effect. Essential oils are characterized by many invaluable activities, including antimicrobial, antioxidant, anti-inflammatory, and immunostimulating. Essential oils may stimulate the immune system via the utilization of their constituents, such as antibodies, cytokines, and dendritic cells. Some essential oils may stimulate the proliferation of immune-competent cells, including polymorphonuclear leukocytes, macrophages, dendritic cells, natural killer cells, and B and T lymphocytes. This review is focused on the ability of essential oils to affect the immune system. It is also possible that essential oil components positively interact with recommended anti-inflammatory and antimicrobial drugs. Thus, there is a need to explore possible synergies between essential oils and their active ingredients for medical use.

Simplex-centroid design as innovative approach in the optimization of antimicrobial effect of Thymus satureioides, Myrtus communis and Artemisia herba alba essential oils against Escherichia coli, Staphylococcus aureus and Candidatropicalis

Essential Oils (EOs) known since Antiquity, and initially obtained by maceration of aromatic plants, are used as diseases' remedies because they contain valuable therapeutic components. Antimicrobial effect's evaluation of formulations established by an augmented centered mixing plan for three Moroccan medicinal and aromatic plants' essential oils (EOs): Thymus satureioides (T. satureioides), Myrtus communis (M. communis) and Artemisia herba alba (A. herba alba) against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) and Candida tropicalis (C. tropicalis). The identification of E.Os chemical compounds was made using Gaz chromatography (GC) and Gaz chromatography coupled to Mass spectrometry (GC/MS).Whereas, the optimization of their antimicrobial effect was performed by experimental design methodology (mixture design) coupled to microdilution method based on Minimal Inhibitory Concentrations (MICs) determination. Results showed that the main components are borneol (34.26%) and α-pinene (31.21%); borneol (27.15%) and 1,8-cineole (21.33%); camphor (14.67%), chrysanthenone (14.10%), and β-thujone (12.60%) for T. satureioides, M. communis and A. herba alba respectively. Optimal mixtures composed of 60% and 40% of T. satureioides and M. communis E.Os; 72% and 28% of T. satureioides and A. Herba alba E.Os; 75% of thyme E.O and 25% of mugwort E.O; predicted the highest antimicrobial effect against E. coli, S. aureus and C. tropicalis, respectively. This study highlights the antimicrobial effect of EOs tertiary mixtures through using mixture design methodology, which may contribute to a successful application in pharmaceutical, food, or cosmetic industries.

Thiamine Demonstrates Bio-Preservative and Anti-Microbial Effects in Minced Beef Meat Storage and Lipopolysaccharide (LPS)-Stimulated RAW 264.7 Macrophages

This study assessed the anti-inflammatory effect of thiamine (TA) in lipopolysaccharide-stimulated RAW264.7 cells and also assessed the preservative properties of TA in minced beef. TA demonstrated a concentration-dependent antimicrobial effect on microbial contaminants. Inhibition zones and MIC from the effect of TA on the tested bacterial strains were respectively within the ranges 15−20 mm and 62.5−700 µg/mL. TA significantly (p < 0.05) decreased all the pro-inflammatory factors [(nitric oxide (NO), prostaglandin E2 (PGE2), TNF-α, IL-6, IL-1β, and nuclear factor-κB (NF-κB)] monitored relative to LPS-stimulated RAW264.7 cells. TA inhibited the expression of both iNOS and COX-2. In minced beef flesh, the growth of Listeria monocytogenes was inhibited by TA. TA improved physicochemical and microbiological parameters of stored minced beef meat compared to control. Principal component analyses and heat maps elucidate the quality of the tested meats.

Botanic Garden as a Factory of Molecules: Myrtus communis L. subsp. communis as a Case Study

A novel perception of botanic gardens as complex “factories of molecules” (Lombardy Region Project–Lr. 25/2016, year 2021), that mediate plant–environment interactions, and are the basis of their utility for humans, is presented. The core-topic is the medicinal plant heritage of the Ghirardi Botanic Garden (Toscolano Maderno, Brescia, Italy) of the University of Milan. In this work, we studied Myrtus communis L. subsp. communis (Myrtaceae) at multiple scale levels: macro- and micromorphological, with special emphasis on the secretory structures responsible for the production of secondary metabolites; phytochemical, with the analysis of the essential oil (EO) composition from leaves (fresh, dried, stored at −20 °C and at −80 °C) and fruits over two consecutive years (2018 and 2019); bio-ecological, with a focus, based on literature data, on the ecology and biological activity of the main EO components. The occurrence of secretory cavities producing terpenes, along with flavonoids, was proven. A high level of chemical variability across the obtained EO profiles emerged, especially that concerning quantitative data. However, regardless of the different conservation procedures, the examined plant part, or the phenological stage, we detected the presence of three ubiquitous compounds: α-pinene, 1,8-cineole, and linalool. The overall results will serve to enrich the Ghirardi Botanic Garden with novel labeling showing accurate and updated scientific information in an Open science perspective.

Optimized Antibacterial Effects in a Designed Mixture of Essential Oils of Myrtus communis, Artemisia herba-alba and Thymus serpyllum for Wide Range of Applications

Nowadays, the combination of molecules influences their biological effects, and interesting outcomes can be obtained from different component interactions. Using a mixture design method, this research seeks to simulate the efficacy of essential oil combinations against various bacteria and forecast the ideal combination. The chemical compositions of Myrtus communis, Artemisia herba-alba and Thymus serpyllum essential oils were analyzed using CG/MS. Then, the combined antibacterial effects were evaluated by testing mixture design formulations using the microdilution bioassay. The main compounds detected for M. communis essential oil were myrtenyl acetate (33.67%), linalool (19.77%) and 1,8-cineole (10.65%). A. herba-alba had piperitone as a chemotype, representing 85%. By contrast, the T. serpyllum oil contained thymol (17.29%), γ-terpinene (18.31%) and p-cymene (36.15%). The antibacterial effect of the essential oils studied, and the optimum mixtures obtained were target strain-dependent. T. serpyllum alone ensured the optimal inhibition against S. aureus and E. coli, while a ternary mixture consisting of 17.1%, 39.6% and 43.1% of M. communis, A. herba-alba and T. serpyllum respectively, was associated with optimal inhibitory activity against B. subtilis. The outcome of this research supports the idea of the boosting effect of essential oil combinations toward better activities, giving better understanding of the usefulness of mixture designs for food, cosmetics, and pharmaceutical applications.

Chemical Variability of Moroccan Myrtle Oil

Thirty-three oil samples isolated from aerial parts of Myrtus communis L. harvested in seven localities, from Northern to Central Morocco, have been analyzed by combination of chromatographic and spectroscopic techniques. The 33 compositions have been subjected to statistical analysis, hierarchical cluster analysis (HCA) and principal component analysis (PCA). Two groups have been differentiated on the basis of their myrtenyl acetate and α-pinene contents and each one was sub-divided in two sub-groups according to the contents of 1,8-cineole and linalool. The compositions of our 33 myrtle oil samples may be named as follow by their main components: sub-group IA (13/33): α-pinene/1,8-cineole/linalool; sub-group IB (6/33): 1,8-cineole/α-pinene; sub-group IIA (10/33): 1,8-cineole/myrtenyl acetate; sub-group IIB (4/33): myrtenyl acetate.

Phytocompounds vs. Dental Plaque Bacteria: In vitro Effects of Myrtle and Pomegranate Polyphenolic Extracts Against Single-Species and Multispecies Oral Biofilms

In the last decades, resistant microbial infection rate has dramatically increased, especially infections due to biofilm-producing strains that require increasingly complex treatments and are responsible for the increased mortality percentages compared with other infectious diseases. Considering that biofilms represent a key factor for a wide range of chronic infections with high drug tolerance, the treatment of biofilm-causing bacterial infections represents a great challenge for the future. Among new alternative strategies to conventional antimicrobial agents, the scientific interest has shifted to the study of biologically active compounds from plant-related extracts with known antimicrobial properties, in order to also evaluate their antibiofilm activity. In this regard, the aim of this study has been to assess the antibiofilm activity of polyphenolic extracts from myrtle leaf and pomegranate peel against oral pathogens of dental plaque, an excellent polymicrobial biofilm model. In particular, the in vitro antibiofilm properties of myrtle and pomegranate extracts, also in binary combination, were highlighted. In addition to inhibiting the biofilm formation, the tested polyphenolic extracts have been proven to destroy both preformed single-species and multispecies biofilms formed by Streptococcus mutans, Streptococcus oralis, Streptococcus mitis, and Rothia dentocariosa oral isolates, suggesting that the new natural sources are rich in promising compounds able to counteract biofilm-related infections.

Selection of Optimal Operating Conditions for Extraction of Myrtus Communis L. Essential Oil by the Steam Distillation Method

Myrtus communis L. is one of the important aromatic and medicinal species from the Mediterranean area. It is used in various fields such as culinary, cosmetic, pharmaceutical, therapeutic, and industrial applications. Thus, a Box–Wilson experimental plan was used in this study to select the optimal operating conditions in order to obtain high volumes of essential oils. The factorial design method was applied to evaluate at an industrial scale the effect of major process variables on the essential oil extraction from Myrtus communis L. herbs by the steam distillation method. The input variables considered as significant operating conditions were: X₁—boiler occupancy rate (boilers were filled to 50%, 75%, and 100%), X₂—distillation duration (distillation was continued 60, 75, and 90 min), and X₃—particle size (herbs were cut in sizes of 10, 20, and 30 mm via guillotine). The dependent variable selected, coded as Y, was the essential oil volume obtained (mL). The steps of the classical statistical experimental design technique were complemented with the Taguchi method to improve the extraction efficacy of essential oil from Myrtus communis L., and the optimum parameter conditions were selected: boiler occupancy rate 100%, distillation duration 75 min, and particle size 20 mm. Following the optimum parameters, the GC-MS assay revealed for the Myrtus communis L. essential oil two predominant components, α-pinene—33.14% and eucalyptol—55.09%.

Phytochemical analysis, cytotoxic and antioxidant activities of Myrtus communis essential oil from Morocco

Background

Myrtus communis L. is an aromatic evergreen plant common in Morocco. In addition to its culinary uses, it has been used medicinally as a disinfectant, an antiseptic or as a hypoglycemic agent. However, its cytotoxic activity has not been well investigated so far. The current study describes the chemical composition, cytotoxic and antioxidant activities of Myrtus communis L essential oil obtained from different regions of Morocco.

Methods

Myrtus communis essential oils were obtained by hydrodistillation, and analyzed by gas chromatography coupled with mass spectrometry. Cytotoxic activity was evaluated in murine mastocytoma P815 and MCF-7 breast cancer cells, using the MTT assay. In addition, DNA fragmentation was assessed by gel electrophoresis. The antioxidant effect was determined by measuring bleaching of β-carotene with the linoleic acid and the DPPH radical scavenging methods.

Results

GC-MS analysis showed high amounts of methyl eugenol (18.7%), α-terpineol (15.5%) and geranyl acetate (11.64%) in essential oil from the Benslimane region. In contrast, essential oil from Ouazzane was particularly rich in 1,8-cineole (36.3%). The cytotoxicity results showed that MCF-7 cells were more sensitive than P815 cells to the essential oils from Ouazzane and Benslimane regions with IC50 values of 4 and 6.25 µg/mL, respectively. Moreover, this cytotoxicity was partly associated with DNA fragmentation, which is one of the characteristics of apoptosis. The tested essential oils did not show strong antioxidant activity.

Conclusions

Myrtus communis L. essential oil exhibits a weak antioxidant effect, but induced remarkable cytotoxic activity by a mechanism related to apoptosis, suggesting a possible application of the bioactive compounds as natural anticancer compounds.

Metabolome based volatiles mapping of roasted umbelliferous fruits aroma via HS-SPME GC/MS and peroxide levels analyses

Despite studies on umbelliferous fruits flavor makeup, nothing is known regarding roasting impact on their fruit aroma. Five major umbelliferous crops viz., anise, caraway, coriander, cumin and fennel were analyzed via headspace solid-phase microextraction to reveal for 117 volatile constituents. Oxygenated monoterpenes amounted for the major volatile class in raw fruits at 75% with (E)-anethole, carvone, β-linalool, cuminaldehyde and estragole as major components in anise, caraway, coriander, cumin, and fennel, respectively. Difference was observed in fennel fruit "estragole" levels derived from different origins. Upon roasting, several novel volatiles were detected viz. pyrazines and flavored Milliard type volatiles. Major flavor intensified response was detected in cumin with an increase in its "cuminaldehyde" levels versus a decrease of estragole levels in fennel. Roasted cumin exhibited highest peroxide value 14.2 mEq O₂/Kg, whereas the least was detected in fennel at 6.1 mEq O₂/Kg, though with both values not representing a health hazard.

Proteomic Analysis of the Chlorophyta Dunaliella New Strain AL-1 Revealed Global Changes of Metabolism during High Carotenoid Production

The green microalgae Dunaliella genus is known for the production of high added value molecules. In this study, strain AL-1 was isolated from the Sebkha of Sidi El Hani (Sousse, Tunisia). This isolate was identified both morphologically and genetically via 18S rRNA gene sequence as a member of the genus Dunaliella. Strain AL-1 was found to be closely related to Dunaliella salina, Dunaliella quartolecta and Dunaliella polymorpha with more than 97% similarity. Response surface methodology was used to maximize carotenoid production by strain AL-1 by optimizing its growth conditions. The highest carotenoid content was obtained at salinity: 51, light intensity: 189.89 μmol photons·m^-2·s^-1, and nitrogen: 60 mg·L^-1. Proteomic profiling, using two-dimensional gel electrophoresis, was performed from standard and optimized cultures. We detected 127 protein spots which were significantly differentially expressed between standard and optimized cultures. Among them 16 protein spots were identified with mass spectrometry and grouped into different functional categories using KEGG (Kyoto Encyclopedia of Genes and Genomes) such as photosynthetic Calvin cycle, regulation/defense, energy metabolism, glycolysis, and cellular processes. The current study could be of great interest in providing information on the effect of stressful conditions in microalgae carotenoid production.

Essential Oil and Bioactive Compounds Variation in Myrtle (Myrtus communis L.) as Affected by Seasonal Variation and Salt Stress

The effect of different NaCl concentrations (control, 2, 4 and 6 dS/m) and three harvesting times in different seasons including spring (9 April), summer (5 July), and fall (23 September) was evaluated on essential oil (EO) yield, composition, phenolic, flavonoid content, and antioxidant activity of myrtle. Essential oil yield ranged from 0.2% in control and fall to 1.6% in moderate salinity (4 dS/m) and spring season. The main constituents obtained from gas chromatography/mass spectrometry analysis were α-pinene, 1,8-cineole, limonene, linalool, α-terpineol, and linalyl acetate in which α-pinene ranged from 11.70% in moderate and fall to 30.99% in low salinity (2 dS/m) and spring, while 1,8-cineole varied from 7.42% in high salinity (6 dS/m) and summer to 15.45% in low salinity and spring, respectively. Salt stress also resulted in an increase in total phenolic, flavonoid content, and antioxidant activity. The highest antioxidant activity based on DPPH radical scavenging activity, reducing power (FTC) and β-carotene/linoleic acid model systems was found in plants harvested in spring and summer in high stress condition. The lowest IC₅₀ values obtained in 6 dS/m in spring (375.23 μg/ml) followed by summer (249.41 μg/ml) and fall (618.38 μg/ml). Eight major phenolic and flavonoid compounds were determined in three harvesting times using high performance liquid chromatography analysis. In overall, late harvesting time of myrtle in fall can lead to reduce the most of major EO components, while it can improve the amount of phenolic acids.

Antifungal and Herbicidal Effects of Fruit Essential Oils of Four Myrtus communis Genotypes

The chemical composition of the essential oils isolated by hydrodistillation from the fruits of four selected Myrtus communis L. genotypes from Turkey was characterized by GC-FID and GC/MS analyses. 1,8-Cineole (29.20-31.40%), linalool (15.67-19.13%), α-terpineol (8.40-18.43%), α-pinene (6.04-20.71%), and geranyl acetate (3.98-7.54%) were found to be the major constituents of the fruit essential oils of all M. communis genotypes investigated. The oils were characterized by high amounts of oxygenated monoterpenes, representing 73.02-83.83% of the total oil compositions. The results of the fungal growth inhibition assays showed that the oils inhibited the growth of 19 phytopathogenic fungi. However, their antifungal activity was generally lower than that of the commercial pesticide benomyl. The herbicidal effects of the oils on the seed germination and seedling growth of Amaranthus retroflexus L., Chenopodium album L., Cirsium arvense (L.) Scop., Lactuca serriola L., and Rumex crispus L. were also determined. The oils completely or partly inhibited the seed germinations and seedling growths of the plants. The findings of the present study suggest that the M. communis essential oils might have potential to be used as natural herbicides as well as fungicides.

Myrtucommulone-A Induces both Extrinsic and Intrinsic Apoptotic Pathways in Cancer Cells

Myrtucommulone-A is the active compound derived from Myrtus communis. The molecular targets of myrtucommulone-A is widely unknown, which impedes its potential therapeutic use. In this study, we demonstrated the cytotoxicity of MC-A and its potential to induce apoptosis in cancer cells. Myrtucommulone-A was also found to be antiproliferative and strongly inhibited cancer cell migration. Eighty four apoptotic pathway genes were used to assess the effect of myrtucommulone-A on cancer cells. Myrtucommulone-A mediated an increase in apoptotic genes including Fas, FasL, Gadd45a, Tnf, Tnfsf12, Trp53, and caspase 4. The increase in myrtucommulone-A dose (25 μM versus 6.25 μM) also upregulated the expression of genes, which are involved mainly in apoptosis, regulation of apoptosis, role of mitochondria in apoptotic signaling, cytokine activity, and tumor necrosis factor signaling. Our data indicate that myrtucommulone-A could be utilized as a potential therapeutic compound with its molecular targets in apoptotic pathways.