Antibacterial interactions of pulegone and 1,8-cineole with monolaurin ornisin against Staphylococcus aureus

Characterisation of the essential oil from Iphiona grantioides and investigation of its antibacterial and antioxidant properties

Iphiona grantioides (Boiss) Anderb. is a medicinal plant featuring several traditional uses. Nevertheless, this plant has not been widely investigated by modern medicinal chemistry yet, as also the properties of its extracts.In this study, we report the extraction of the essential oil by hydrodistillation from the leaves of I. grantioides. This was characterised by GC-MS analysis and ten chemical constituents were identified.Our findings demonstrate that the essential oil is effective in inhibiting the growth of bacterial strains, and of Klebsiela pneumonia and Staphylococcus aureus in particular. Additionally, its antioxidant properties were evaluated, and it showed radical scavenging activity in vitro.

Essential oils: a potential alternative with promising active ingredients for pharmaceutical formulations in chronic wound management

Chronic wound is a major clinical challenge that complicates wound healing, mainly associated with bacterial biofilms. Bacterial burden damages tissue and persists inflammation, failing to granulate, leading to morbidity and mortality. Various therapeutic strategies and approaches have been developed for chronic wound healing in clinical practice. As treating biofilm infection is crucial in chronic wounds, a potent antibiofilm agent, essential oils have been explored extensively for their therapeutic properties and as a replacement for antibiotic therapy. Currently, several studies on essential oils and their active compounds in therapeutics, such as adjunctive therapies, nanotechnology-based treatment and their drug delivery systems, help heal chronic wounds. The antimicrobial, anti-inflammatory and antioxidant properties of essential oils make them distinct and are renowned as natural remedies to improve the healing of infected chronic wounds. Consequently, it accelerates wound closure by reducing inflammation, increasing angiogenesis and tissue regeneration. This review focuses on different essential oils and their active compounds that are exploited for the treatment of biofilm infection, chronic inflammation and wound healing. Thus, an effective novel treatment can be developed to improve the current treatment strategy to overcome multidrug resistance bacteria or antibiotic resistance in various chronic wound infections that support wound healing.

Development, Optimization, and Evaluation of New Gel Formulations with Cyclodextrin Complexes and Volatile Oils with Antimicrobial Activity

This study aimed to develop and evaluate hydrogels containing a cyclodextrin complex with clove essential oil and other free volatile oils with antimicrobial properties (tea tree and rosemary essential oils), focusing on their pharmaco-technical and rheological characteristics. The formulations varied in the Carbopol 940 (a hydrophilic polymer) and volatile oils' concentrations. Rheological analysis indicated that the gels displayed pseudoplastic behavior, with the flow index (n) values below 1, ensuring appropriate consistency and handling. The results showed that increasing the Carbopol concentration significantly enhanced the yield stress, consistency index, and viscosity, with gel B, containing 1% Carbopol, 1.5% tea tree essential oil, and 1.5% rosemary essential oil, demonstrating optimal stability and rheological properties. At the same time, the concentration of volatile oils was found to modulate the gels' flow parameters, but their effect was less pronounced than that of the gel-forming polymer. Antimicrobial testing revealed that both gel B and gel E (containing 1% Carbopol, 2% tea tree essential oil, and 2% rosemary essential oil) exhibited antimicrobial activity against Gram-positive, Gram-negative bacteria, and Candida spp., with gel E showing superior efficacy against Candida tropicalis. The antimicrobial effects were likely influenced by the higher concentrations of tea tree and rosemary essential oils in gel E. Overall, the study demonstrates that the concentration of Carbopol 940 primarily determines the gel's rheological behavior, while volatile oil concentration modulates antimicrobial effectiveness.

Application of bacterial nanocellulose film loaded with sodium nitrite, sumac, and black carrot extracts to reduce sodium nitrite, extend shelf life, and inhibit Clostridium perfringens in cooked beef ham

This study aimed to develop innovative bacterial nanocellulose (BNC) films incorporated with sodium nitrite (SN), sumac extract (SE), and black carrot extract (BCE) to reduce sodium nitrite, extend shelf life, and inhibit Clostridium perfringens in cooked beef ham. The ham covered with BNC film immersed in SE (10 % w/v) + BCE (5 % w/v) + SN (125 ppm) (SE10BCE5SN125) exhibited the lowest microbial load (4.39, 4.32, 3.83, and 4.6 log cycles reductions in total viable count, lactic acid bacteria, Enterobacteriaceae, and C. perfringens, respectively) and the lowest oxidation rate (70 % reduction compared to control) on day 28 of storage. The samples covered with SE10BCE5SN125 film had also the lowest level of residual nitrite (64 % lower compered to positive control). Positive control (ham containing 120 ppm SN) and ham covered with SE10BCE5SN125 film had the highest redness. It was concluded that the films developed in this study have the potential to reduce the use of sodium nitrite in beef ham production.

Antibiofilm Effect of Sequential Application of Ozonated Water, Acetic Acid and Lactic Acid on Salmonella Typhimurium and Staphylococcus aureus Biofilms In Vitro

Biofilms are highly resistant to disinfectants and antimicrobials and are known as the primary source of food contamination. Salmonella Typhimurium (S. Typhimurium) and Staphylococcus aureus (S. aureus) have an excellent ability to form biofilm. This study aimed to evaluate the antibiofilm activity of ozonated water (O), acetic acid (AA), and lactic acid (LA), individually and sequentially, against biofilms of S. Typhimurium and S. aureus formed on the polystyrene surfaces. The antibiofilm effects of the treatments were evaluated using crystal violet staining and the viable count determination methods. In the staining method, the highest percentage of biofilm mass reduction was induced by successive use of ozonated water and acetic acid (O-AA), which reduced S. aureus biofilm mass by 44.36%. The sequential use of ozonated water and lactic acid (O-LA) could decrease S. Typhimurium biofilm mass by 57.26%. According to the viable count method, the most effective treatment was the sequential use of ozonated water and lactic acid (O-LA), which reduced S. aureus and S. Typhimurium biofilms by 1.76 and 4.06 log, respectively. It was concluded that the sequential use of ozonated water and organic acids can be considered a practical and environmentally friendly approach to control biofilms.

Phytochemical characterisation of dichloromethane and methanolic extracts of the Ziziphora tenuior leaves and evaluation of their antioxidant and antibacterial activities

Medicinal plants, known for their antibacterial phytocompounds and secondary metabolites, offer promising potential in combating antibiotic-resistant bacteria. This study aimed to perform a phytochemical analysis of the methanol and dichloromethane extracts obtained from Ziziphora tenuior leaves using GC-MS. Furthermore, the antioxidant activity of the extracts was evaluated through the DPPH assay. And, their antibacterial activity was assessed against S. aureus, E. coli, methicillin-resistant S. aureus, and vancomycin-resistant enterococcus (VRE) bacterial strains. Based on the results 90-92% of these extracts consisted of phytocompounds with pharmaceutical properties. Of these, 5-methyl- 2-(1-methylethylidele), Cyclohexanone (Pulegone; C10H16O) comprised the highest percentage of the extracts, constituting 62% of methanolic extract and 81% of dichloromethane extract. Also, both methanolic and dichloromethane extracts showed potent antioxidant activity with IC50 of 277.6 µg/ml and 49.6 µg/ml, respectively. Moreover, these extracts demonstrated considerable antibacterial activity against the tested pathogens, especially against S. aureus and VRE.

Comparison of quantity, quality and antibacterial activity of essential oil Mentha longifolia (L.) L. under different traditional and modern extraction methods

Extraction is the first and most important step in obtaining the effective ingredients of medicinal plants. Mentha longifolia (L.) L. is of considerable economic importance as a natural raw material for the food and pharmaceutical industries. Since the effect of different extraction methods (traditional and modern methods) on the quantity, quality and antimicrobial activity of the essential oil of this plant has not been done simultaneously; the present study was designed for the first time with the aim of identifying the best extraction method in terms of these features. For this purpose, extracting the essential oil of M. longifolia with the methods of hydrodistillation with Clevenger device (HDC), steam distillation with Kaiser device (SDK), simultaneous distillation with a solvent (SDE), hydrodistillation with microwave device (HDM), pretreatment of ultrasonic waves and Clevenger (U+HDC) and supercritical fluid (SF) were performed. Chemical compounds were identified by gas chromatography coupled with mass spectrometer (GC-MS). Antimicrobial activity of essential oils against various clinical microbial strains was evaluated by agar diffusion method and determination of the minimum inhibitory concentration and minimum bactericidal concentration (MIC and MBC). The results showed that the highest and lowest yields of M. longifolia leaf essential oil belonged to HDC (1.6083%) and HDM (0.3416%). The highest number of compounds belonged to SDK essential oil and was equal to 72 compounds (with a relative percentage of 87.13%) and the lowest number of compounds was related to the SF essential oil sample (7 compounds with a relative percentage of 100%). Piperitenone (25.2-41.38%), piperitenone oxide (22.02-0%), pulegone (10.81-0%) and 1,8-cineole (5-35.0%) are the dominant and main components of M. longifolia essential oil were subjected to different extraction methods. Antimicrobial activity results showed that the lowest MIC value belonged to essential oils extracted by HDM, SDK, SDE and U+HDC methods with a value of 1000 μg/mL was observed against Gram-negative bacteria Shigella dysenteriae, which was 5 times weaker than rifampin and 7 times weaker than gentamicin. Therefore, it can be concluded that in terms of efficiency of the HDC method, in terms of the percentage of compounds of the HDM method, and in terms of microbial activity, the SDK, HDM and U+HDC methods performed better.

Antibacterial and Antibiofilm Activity of Croton urticifolius Lam. Essential Oil Via Membrane Disruption

Antimicrobial resistance is a global health issue, in which microorganisms develop resistance to antimicrobial drugs, making infections more difficult to treat. This threatens the effectiveness of standard medical treatments and necessitates the urgent development of new strategies to combat resistant microbes. Studies have increasingly explored natural sources of new antimicrobial agents that harness the rich diversity of compounds found in plant species. This pursuit holds promise for the discovery of novel treatments for combating antimicrobial resistance. In this context, the chemical composition, antibacterial, and antibiofilm activities of the essential oil from Croton urticifolius Lam. leaves (CuEO) were evaluated. CuEO was extracted via hydrodistillation, and its chemical constituents were identified via gas chromatography-mass spectrometry (GC/MS). The antibacterial activity of CuEO was evaluated in a 96-well plate via the microdilution method, and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values were determined. The effect of CuEO on biofilm formation was assessed by quantifying the biomass using crystal violet staining and viable cell counting. In addition, alterations in the cellular morphology of biofilms treated with CuEO were examined using scanning electron microscopy (SEM) and laser confocal microscopy. GC/MS analysis identified 26 compounds, with elemicine (39.72%); eucalyptol (19.03%), E-caryophyllene (5.36%), and methyleugenol (4.12%) as the major compounds. In terms of antibacterial activity, CuEO showed bacteriostatic effects against Staphylococcus aureus ATCC 700698, S. aureus ATCC 25923, Staphylococcus epidermidis ATCC 12228, and Escherichia coli ATCC 11303, and bactericidal activity against S. aureus ATCC 700698. In addition, CuEO significantly inhibited bacterial biofilm formation. Microscopic analysis showed that CuEO damaged the bacterial membrane by leaching out the cytoplasmic content. Therefore, the results of this study show that the essential oil of C. urticifolius may be a promising natural alternative for preventing infections caused by bacterial biofilms. This study is the first to report the antibiofilm activity of C. urticifolius essential oil.

Comparison of autoclaving and γ-radiation impact on four spices aroma profiles and microbial load using HS-SPME GC-MS and chemometric tools

Herbal spices are widely consumed as food additives owing to their distinct aroma and taste as well as a myriad of economic and health value. The aroma profile of four major spices including bay leaf, black pepper, capsicum, and fennel was tested using HS-SPME/GC-MS and in response to the most widely used spices´ processing methods including autoclaving and γ-radiation at low and high doses. Additionally, the impact of processing on microbial contamination of spices was tested using total aerobic count. GC-MS analysis led to the identification of 22 volatiles in bay leaf, 34 in black pepper, 23 in capsicum, and 24 in fennel. All the identified volatiles belonged to oxides/phenols/ethers, esters, ketones, alcohols, sesquiterpene and monoterpene hydrocarbons. Oxides/phenol/ethers were detected at high levels in all tested spices at ca. 44, 28.2, 48.8, 61.1%, in bay leaves, black pepper, capsicum, and fennel, respectively of the total blend and signifying their typical use as spices. Total oxides/phenol/ethers showed an increase in bay leaf upon exposure to γ-radiation from 44 to 47.5%, while monoterpene hydrocarbons were enriched in black pepper upon autoclaving from 11.4 in control to reach 65.9 and 82.6% for high dose and low dose of autoclaving, respectively. Cineole was detected in bay leaf at 17.9% and upon exposure to autoclaving at high dose and γ-radiation (both doses) its level increased by 29-31%. Both autoclaving and γ-radiation distinctly affected aroma profiles in examined spices. Further, volatile variations in response to processing were assessed using multivariate data analysis (MVA) revealing distinct separation between autoclaved and γ-radiated samples compared to control. Both autoclaving at 115 °C for 15 min and radiation at 10 kGy eliminated detected bioburden in all tested spices i.e., reduced the microbial counts below the detection limit (< 10 cfu/g).

Savory and Peppermint Essential Oils-Loaded Emulsions and Nanoemulsions Effects on Enterococcus faecium Isolated from Vacuum-Packed Cured Sausage

In this work, Enterococcus faecium, the specific spoilage organism responsible for bloating spoilage of sliced vacuum-packed cured emulsion-type sausage, was isolated and identified through molecular and biochemical techniques, and then the antibacterial activities of savory-loaded nanoemulsion (SNE), savory-loaded emulsion (SE), peppermint-loaded nanoemulsion (PNE), and peppermint-loaded emulsion (PE) were investigated against spoilage microorganisms. Nanoemulsions with average particle sizes in the range of 109.27 to 118.55 nm were developed by sonication and remained more stable than emulsion samples for 2 weeks. Regardless of emulsion type, the highest antimicrobial activity was detected for savory-loaded samples. Moreover, the significant enhancements in the antimicrobial activity of SNE compared to SE were confirmed by increasing the inhibition zone diameter (17.6%) and decreasing MIC (50%) and MBC (50%) due to the higher specific surface area of smaller droplets. The TEM and SEM micrographs confirmed the inhibitory effects of SNE due to the significant changes in the cell wall integrity of Enterococcus faecium.

In silico and in vitro studies: investigating the chemical composition, DFT, molecular docking, and dynamic simulation of Satureja candidissima (Munby) Briq essential oil as a potential antibacterial agent

This study aimed to investigate the chemical composition and antibacterial properties of the essential oil (EO) derived from the aerial parts of Satureja candidissima (Munby) Briq (SC), as well as the mechanisms of interaction between SCEO chemical components and target proteins related to antibacterial activity mechanisms using a molecular docking approach, and for more accuracy molecular dynamic simulation and DFT calculations were carried out. The GC-MS technique was used to analyze the chemical composition of SCEO. The results showed that SCEO contained various chemical compounds, with pulegone being identified as the major component (53.26%). The results also indicated the presence of (+)-menthone (11.02%), borneol (4.43%), 2-cyclohexen-1-one, 3-methyl-6-(1-methylethylidene) (2.50%), and 3-octanol (2.09%). The study revealed that the SCEO displayed antibacterial activity against all tested gram-positive bacteria. To further understand the mechanism behind its antibacterial activity, in silico molecular docking studies were performed. The results indicated that the antibacterial effect of SCEO compounds could be due to the combination with enoyl-[acyl-carrier-protein] reductase [NADPH] FabI (PDB ID: 4ALL) in a variety of ways. The molecular dynamics simulation analysis yielded favorable outcomes for the docked complex involving 1H-cycloprop[e]azulen-7-ol, decahydro-1,1,7-trimethyl-4-methylene, and 1,4,7-tetramethyldecahydro-1H-cyclopropa[e]azulen-4-ol with enoyl-[acyl-carrier-protein] reductase [NADPH]. Geometry optimization, coupled with Density Functional Theory (DFT), can be employed to assess the importance of quantum chemical descriptors in elucidating potential antibacterial activity. Quantum descriptors were computed based on EHOMO and ELUMO. The results of this study provide important insights into the potential use of Satureja candidissima (Munby) Briq EO as antibacterial agent.Communicated by Ramaswamy H. Sarma.

Effect of cardamom consumption on inflammation and blood pressure in adults: A systematic review and meta-analysis of randomized clinical trials

Cardamom has the potential to offer anti-inflammatory and antihypertensive advantages, but the findings from clinical trials have been inconsistent. To address this knowledge gap, the present systematic review and meta-analysis were conducted to evaluate the anti-inflammatory and antihypertensive effects of cardamom in adults. We systematically searched databases including PubMed, Scopus, and ISI Web of Sciences, for papers published up to October 2022 to identify clinical studies. Eight eligible studies were included in the meta-analysis. A fixed model was used to estimate weighted mean difference (WMD), standardized mean difference (SMD), and 95% confidence interval (95% CI). The results showed that cardamom significantly reduced the levels of inflammatory factors, including hs-CRP (SMD: -0.60 mg/dL; 95% CI: -0.78 to 0.42), IL-6 (WMD: -1.25 mg/dL; 95% CI: -1.48 to -1.03), TNF-α (WMD: -2.10 kg; 95% CI: -2.36 to -1.84, p < .001), and measures of systolic (WMD: -0.54 mmHg, 95% CI: -0.88, -0.19, p = .002) and diastolic (WMD: -0.90 mmHg; 95% CI: -1.07 to -0.73) blood pressure. The current meta-analysis showed that cardamom can help reduce inflammation and improve blood pressure. However, due to the limited number of studies, caution must be exercised when interpreting the current results.

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.

Eucalyptus camaldulensis Dehnh Leaf Essential Oil from Palestine Exhibits Antimicrobial and Antioxidant Activity but No Effect on Porcine Pancreatic Lipase and α-Amylase

Eucalyptus camaldulensis Dehnh is a tree species that is commonly used for various purposes, including forestry, agroforestry, and conservation. The present investigation was designed to determine the composition of E. camaldulensis leaves essential oil and estimate its free radicals, porcine pancreatic lipase, α-amylase inhibitory, and antimicrobial properties in vitro. The chemical constituents were analyzed using the gas chromatography-mass spectrometry (GC-MS) technique. DPPH (2,2-diphenyl-1-picrylhydrazyl), p-nitrophenyl butyrate, and 3,5-dinitro salicylic acid (DNSA) methods were employed to estimate the antioxidant, antiobesity, and antidiabetic effects of the essential oil. The microdilution assay was employed to assess the antimicrobial efficacy of the substance against a total of seven distinct microbial species. The GC-MS results revealed that E. camaldulensis essential oil contains 52 components that makeup 100% of the entire oil. The main chemical constituents in E. camaldulensis essential oil are p-cymene (38.64%), followed by aromadendrene (29.65%), and 1,8-cineol (6.45%), with monocyclic monoterpene being the most abundant phytochemical group, followed by the sesquiterpene hydrocarbon group, representing 44.27 and 31.46%, respectively. The essential oil showed a weak antioxidant effect and had no antilipase or antiamylase effects. At the same time, the oil showed a strong antimicrobial effect against methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus aureus, and Proteus vulgaris, which was even more potent than the positive controls, ciprofloxacin and ampicillin, which had MIC doses of 0.2 ± 0.01, 0.2 ± 0.01, and 6.25 ± 0.1 µg/mL, respectively. It also has a strong anti-Candida albicans effect with a MIC of 0.2 ± 0.01 µg/mL. In light of these findings, in vivo studies should be conducted to determine the efficiency of the E. camaldulensis essential oil in treating microbial infections.

Nutritional and chemical composition of Alpinia zerumbet leaves, a traditional functional food

Alpinia zerumbet, a species of the Zingiberaceae family, is a common plant in tropical and subtropical areas used in traditional medicine to treat various diseases and also included as food in the traditional Okinawan diet (Japan). The leaves and rhizomes of this plant are used as spice and flavoring in foods such as rice, meats, and pasta. Studies of the chemical and nutritional characteristics of fresh leaves and of leaves submitted to thermal treatments such as boiling and steaming are lacking. In the current study, the leaves of A. zerumbet were subjected to boiling or steaming for 10, 20, and 30 min as part of the thermal treatments. The study also provides noteworthy results regarding the proximate composition, physical-chemical data, minerals, phenolic compounds, antioxidant activity, volatile compounds, and LC-MS chromatographic profiles of the extracts produced with fresh leaves and with thermal treatments. The carbohydrate content of A. zerumbet leaves improved during the thermal treatments, showing an increase after steaming (18.86 to 19.79%) and boiling for 30 min (25.85%). After boiling treatment for 20 min, a significant amount of protein was found (6.79%) and all heat treatments resulted in low content of lipid (<1.0%). The boiling treatment for 10 min (BT10) resulted in the highest concentrations of total phenolic components (TPC), 339.5 mg/g, and flavonoids (TF), 54.6 mg/g, among the three thermal treatments (BT10, BT20 and BT30). The results of the steaming treatments (ST 10, 20, and 30 min) differed, with ST20 leading to higher TPC (150.4 mg/g) and TF (65.0 mg/g). The quantity of total phenolics and flavonoids, as well as the antioxidant activity, were significantly affected by the cooking method and the length of time of sample exposure to heat. The samples boiled for 30 and 10 min had higher concentrations of antioxidant activity as measured by the phosphomolybdenum and DPPH methods (151.5 mg/g of extract and 101.5 μg/mL, respectively). Thirty-eight volatile organic compounds (VOCs) were identified by chromatographic analysis of fresh and thermally treated leaves of A. zerumbet. Terpenoids were the predominant class of volatile compounds in the fresh leaves and in all thermal treatments. p-Cymene, 1,8-cineole, 4-terpineol, linalool, α-copaene and β-bisabolene have the greatest impact on overall aroma perception, with odor activity values (OAV) greater than five. Among the phenolic compounds identified by LC-HRMS in the extracts of fresh and thermally treated leaves were proanthocyanidins, (+) catechin, (-) epicatechin, quercetin-3-O-glucoronide, isorhamnetin-3-O-glucoronide, kaempferol-3-O-rutinoside, pinocembrin, alpinetin, pinostrobin, and other compounds. The present results support the traditional use of this plant as a potential food with properties that certainly contribute to health improvement.

1,8-cineole (eucalyptol): A versatile phytochemical with therapeutic applications across multiple diseases

1,8-cineole (Eucalyptol), a naturally occurring compound derived from botanical sources such as eucalyptus, rosemary, and camphor laurel, has a long history of use in traditional medicine and exhibits an array of biological properties, including anti-inflammatory, antioxidant, antimicrobial, bronchodilatory, analgesic, and pro-apoptotic effects. Recent evidence has also indicated its potential role in managing conditions such as Alzheimer's disease, neuropathic pain, and cancer. This review spotlights the health advantages of 1,8-cineole, as demonstrated in clinical trials involving patients with respiratory disorders, including chronic obstructive pulmonary disease, asthma, bronchitis, and rhinosinusitis. In addition, we shed light on potential therapeutic applications of 1,8-cineole in various conditions, such as depression, epilepsy, peptic ulcer disease, diarrhea, cardiac-related heart diseases, and diabetes mellitus. A comprehensive understanding of 1,8-cineole's pharmacodynamics and safety aspects as well as developing effective formulations, might help to leverage its therapeutic value. This thorough review sets the stage for future research on diverse health benefits and potential uses of 1,8-cineole in tackling complex medical conditions.

Antibacterial and Angiotensin I-Converting Enzyme (ACE) Inhibition Activities of Essential Oil from Java Cardamom (Amomum compactum) Fruit

The essential oil has been reported to be one of the Angiotensin I-Converting Enzyme (ACE) inhibitor resources. Moreover, it has been proven against bacterial pathogens that cause infectious diseases. Amomum compactum is one source of essential oil, known as Javanese cardamom is a spice herb commonly used for flavouring food and traditional medicine in Indonesia. However, ACE inhibition activity of A. compactum has not been reported. The purposes of this study were to identify the main constituent of volatile compounds, inhibition activity toward bacteria, and antihypertension potency of A. compactum essential oils. Volatile compounds were investigated using Gas Chromatography-Mass Spectrometry (GC-MS). The antimicrobial activity was observed using the microdilution method toward Pseudomonas aeruginosa, Bacillus subtilis, Escherichia coli, and Staphylococcus aureus. The antihypertension effect was studied using an ACE inhibition assay. The result showed that eucalyptol was a primary compound of A. compactum fruit either in Banjar (BJR) and Bogor (BGR) essential oils with the value of 62.22% and 66.23%, respectively. Both BJR and BGR are more active to inhibit gram-positive bacteria (B. subtilis) with MIC values of 1 mg/mL. Meanwhile, the BJR exhibited a higher inhibitory activity effect toward ACE compared to BGR with the value of IC50 64.86 ± 0.57 μg/mL. These findings suggest that A. compactum essential oil can be the potential to lead to the treatment of hypertension as an ACE inhibitor and antibacterial agent.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12088-023-01080-x.

1,8-Cineol (Eucalyptol) Disrupts Membrane Integrity and Induces Oxidative Stress in Methicillin-Resistant Staphylococcus aureus

Due to the increased emergence of drug-resistant bacteria, the declining efficiency of traditional antimicrobials has generated severe concerns in recent years. Subsequently, more interest in other antimicrobial agents from natural resources draws more attention as an alternative to conventional medications. This study investigated the bactericidal mechanism of monoterpene 1,8-cineol (eucalyptol), a major compound of various essential oils, against methicillin-resistant Staphylococcus aureus (MRSA). The antibacterial activity of 1,8-cineol was assessed by an MTT assay against clinical and reference MRSA strains. A cell membrane integrity test, followed by zeta potential (ZP) measurements, was performed to evaluate the disruption of the bacterial membrane integrity. Additionally, the cytotoxic effect of this molecule on MRSA bacteria was investigated by monitoring reactive oxygen species (ROS) generation, lipid peroxidation (MDA), and antioxidant enzyme activities (CAT and SOD). Regarding the anti-staphylococcal effect, the obtained results revealed the antibacterial efficacy of 1,8-cineol wherein the minimum inhibitory concentrations were equal to 7.23 mg/mL. Furthermore, it enhanced membrane permeability, with a 5.36-fold increase in nucleic acid and protein leakage as compared with untreated strains, along with the alteration of surface charge (ZP) in MRSA cells. The tested compound caused an increase in ROS generation reaching 17,462 FU and MDA production, reaching 9.56 μM/mg protein, in treated bacterial cells, along with a decrease in oxidative stress enzymes activities. Our findings suggest that 1,8-cineol has the ability to damage the membrane integrity and induce ROS-mediated oxidative stress in MRSA cells, leading to its antagonistic effect against this pathogen and consequently aiding in the reversal of antibiotic resistance.

Mentha longifolia Essential Oil and Pulegone in Edible Coatings of Alginate and Chitosan: Effects on Pathogenic Bacteria in Lactic Cheese

Mentha longifolia is a valuable medicinal and aromatic plant that belongs to Lamiaceae family. This study looked at the antibacterial effects of M. longifolia essential oil and pulegone in edible coatings made of chitosan and alginate on the growth of Staphylococcus aureus, Listeria monocytogenes, and Escherichia coli in cheese. For this purpose, first fresh mint plant was collected from the cold region of Jiroft in Kerman province. Plant samples were dried in the shade at ambient temperature, and essential oil was prepared using Clevenger. The essential oil was analyzed by gas chromatography using mass spectrometric (GC/MS) detection. The major composition of M. longifolia oil was pulegone (26.07%), piperitone oxide (19.72%), and piperitone (11.88%). The results showed that adding M. longifolia essential oils and pulegone to edible coatings significantly reduced the growth of bacteria during storage. The bacterial population decreased by increasing the concentration of chitosan, M. longifolia, and pulegone in edible coatings. When the effects of pulegone and M. longifolia essential oils on bacteria were compared, it was found that pulegone had a stronger effect on bacterial population reduction. Coating treatments showed more antibacterial activity on E. coli than other bacteria. In general, the results of this research showed that alginate and chitosan coatings along with M. longifolia essential oil and its active ingredient pulegone had antibacterial effects against S. aureus, L. monocytogenes, and E. coli in cheese.

HS-SPME coupled with GC-MS for elucidating differences between the volatile components in wild and cultivated Atractylodes chinensis

INTRODUCTION

Atractylodes chinensis is a Chinese herb that is used in traditional medicine; it contains volatile components that have enormous potential for pharmaceutical, food, and cosmetic applications. The destruction of wild resources demands significant improvement in the quality of artificial cultivation of Atractylodes chinensis. However, little is known about the compositional differences in the volatile substances derived from the wild and cultivated varieties of Atractylodes chinensis.

OBJECTIVES

We aimed to evaluate the specific components of Atractylodes chinensis and analyse the similarities and differences between the volatile components and metabolic pathways in the wild and cultivated varieties.

MATERIAL AND METHODS

Metabolomic analysis using gas chromatography-mass spectrometry (GC-MS) was employed following the extraction of volatile components from Atractylodes chinensis using headspace solid-phase microextraction (HS-SPME).

RESULTS

A total of 167 volatile metabolites were extracted, and 137 substances were matched with NIST and Wiley databases. Among them, 76 compounds exhibited significant differences between the two sources; these mainly included terpenes, aromatics, and esters. KEGG enrichment analysis indicated that the differential metabolites were primarily involved in the biosynthesis of secondary metabolites, terpene biosynthesis, and limonene and pinene degradation; all these pathways have geranyl diphosphate (GDP) as the common link.

CONCLUSION

The total content of volatile substances extracted from wild Atractylodes chinensis was 2.5 times higher than that from the cultured variety; however, each source had different dominant metabolites. This study underscores the necessity for protecting wild Atractylodes chinensis resources, while enhancing the quality of cultivated Atractylodes chinensis.

Secondary Terpenes in Cannabis sativa L.: Synthesis and Synergy

Cannabis is a complex biosynthetic plant, with a long history of medicinal use. While cannabinoids have received the majority of the attention for their psychoactive and pharmacological activities, cannabis produces a diverse array of phytochemicals, such as terpenes. These compounds are known to play a role in the aroma and flavor of cannabis but are potent biologically active molecules that exert effects on infectious as well as chronic diseases. Furthermore, terpenes have the potential to play important roles, such as synergistic and/or entourage compounds that modulate the activity of the cannabinoids. This review highlights the diversity and bioactivities of terpenes in cannabis, especially minor or secondary terpenes that are less concentrated in cannabis on a by-mass basis. We also explore the question of the entourage effect in cannabis, which studies to date have supported or refuted the concept of synergy in cannabis, and where synergy experimentation is headed, to better understand the interplay between phytochemicals within Cannabis sativa L.