Search Results (51)

In this study, we investigated the chemical composition, antimicrobial and antibiofilm activities, and cytotoxicity of Thuja occidentalis L. (thuja) and Myrtus communis L. (myrtle) essential oils (EOs) to evaluate their potential as natural alternatives for topical applications. Thuja EOs were extracted from fresh and dried leaves and cones, while myrtle EO was extracted from fresh leaves. GC-MS analysis revealed that myrtle EO was rich in oxygenated monoterpenes (58.2%), predominantly eucalyptol (41.86%) and α-pinene (20.98%). In contrast, thuja EOs were dominated by monoterpene hydrocarbons (55–82%), with α-pinene as the major component (29–66%), and their composition varied markedly with plant organ and moisture state. Myrtle EO displayed the most potent and broad-spectrum antimicrobial activity, with MIC values as low as 3.096 µL/mL against Staphylococcus aureus and Escherichia coli, and effectively inhibited microbial adherence. Thuja EOs showed selective activity, particularly against Gram-positive bacteria and Candida parapsilosis, with EOs extracted from fresh leaves and cones exhibiting the lowest MICs (1.95–7.8 µL/mL). All EOs did not show cytotoxicity to human keratinocytes at concentrations ≤125 µg/mL and, when diluted to 0.05%, indicated excellent skin compatibility in human patch tests. This study suggests that myrtle and thuja EOs, particularly myrtle, are promising and safe natural antimicrobial agents for dermatological and cosmetic formulations. Full article

The essential oil or extract of Lemon myrtle (Backhousia citriodora F. Muell.), belonging to the family Myrtaceae and the genus Backhousia, exhibits anti-inflammatory and antioxidant properties. However, limited information exists on the safety of water extracts from its leaves. The present study aimed to assess the safety of lemon myrtle water extract as a functional food by performing genotoxicity studies and repeated-dose oral toxicity. Although the bacterial reverse mutation test (Ames test) yielded positive results, in vivo mammalian erythrocyte micronucleus and alkaline comet assays yielded negative results. In a 28-day oral toxicity study, the extract was orally administered to male and female Crl:CD rats at doses of 0, 250, 500, and 1000 mg/kg bw/day. Notably, the extract induced no adverse effects, and the no-observed-adverse-effect level was 1000 mg/kg bw/day in male and female rats. Despite its genotoxicity in vitro, the extract did not exhibit genotoxicity in vivo. Moreover, no signs of toxicity were observed in the general toxicity study. Overall, these results suggest that lemon myrtle water extract does not pose a substantive genotoxic risk at practical oral exposure levels. Full article

Background: Myrtus communis L. is a typical aromatic species of the Mediterranean basin, whose leaves are rich in essential oil known for its biological properties. Methods: The essential oil of Tunisian Myrtus communis L. leaves was extracted via hydrodistillation using a Clevenger-type apparatus and optimized using a complete factorial design including three factors with two different modalities and one factor with three modalities, hence the total number of experiments N_total = 2³ × 3¹. This optimization concerns the yield, the terpene composition by GC-MS and the antioxidant activity by the two radical scavenging assays, DPPH and ABTS. Four factors were retained, namely, the type of leaf used (dry or fresh sample), the leaf granulometry (whole or ground), the extraction time (1 h 30 min, 2 h 30 min and 3 h 30 min) and the water volume/plant material ratio (1/4 and 1/10). Results: The dry and whole leaves, duration 3 h 30 min, and V/M 1/10 modalities gave the best yield of essential oil (0.77%). The optimal contents of the majority of the terpene compounds, 1,8-cineole (37.23%), α-pinene (54.79%), myrtenyl acetate (23.43%) and limonene (17.77%), were recorded using the modalities dry and whole leaves, duration 2 h 30 min, V/M 1/10; dry and ground leaves, duration 1 h 30 min, V/M 1/4; fresh and whole leaves, duration 3 h 30 min, V/M 1/4; and fresh and whole leaves, duration 3 h 30 min, V/M 1/4, respectively. The antioxidant activity of the essential oil of myrtle leaves was optimized for the two DPPH (7.477 mg TE/g EO) with the GDL, duration 3 h 30 min, V/M 1/4 and ABTS assays (14.053 mg TE/g EO) with WDL terms, duration 3 h 30 min, V/M 1/10. Conclusions: Optimizing essential oil extraction is of significant interest to the cosmetic, perfumery, and pharmaceutical industries, which are constantly seeking optimal conditions to enhance essential oil yield and to ensure a high concentration of terpenic compounds, valued for their aromatic qualities and diverse biological activities. Full article

Myrtle (Myrtus communis L.) is a rich source of bioactive compounds and nutraceuticals of different polarities obtained from different parts of the plant, whose synergistic effect could be harnessed through the formulation of capsules. The aim of this work was to investigate the antimicrobial activity of three myrtle formulations: essential oil and aqueous leaf extract and supercritical fruit extract, as well as the retention of volatile, phenolic and lipid compounds in low-viscosity alginate capsules obtained by the electrostatic extrusion microencapsulation of these formulations combined. At a temperature of 48 °C, 1.27% emulsifier and 3% CaCl₂, 72.86% of the volatiles, 61.13% of the phenolics and 62.80% of the lipids were retained. All tested extracts showed good antibacterial activity, especially against Staphylococcus aureus and Listeria monocytogenes, which were the most sensitive. An exceptionally high inhibitory effect was achieved by aqueous leaf extract against L. monocytogenes (35.25 mm) and essential oil against Escherichia coli (28 mm). Supercritical extract and essential oil showed good antifungal activity, and none of the extracts showed inhibitory activity against lactic acid bacteria. Full article

Myrtle oil extracted from the spent berries of myrtle liqueur production, using 2-methyltetrahydrofuran, was used to increase the oxidative stability of sunflower oil (SFO). Three blending ratios (5%, 10%, and 15% w/w) and the SFO without any addition were subjected to forced aging conditions at 70 °C for 21 days. The changes in peroxide value (PV), p-anisidine value (AV), total oxidation value (totox), and conjugated dienes and trienes were evaluated during forced aging. The oxidative stability of the blends was also assessed by the spin trapping method coupled with Electron Paramagnetic Resonance spectroscopy. Myrtle oil at 5% provided the best results, increasing the oxidative stability of SFO by reducing the PV and slowing the onset of secondary oxidation products, as measured by the AV and conjugated trienes. The 15% blend, despite its high levels of PV, AV, conjugated dienes, and trienes during storage, protects SFO from oxidation. The blends of SFO with unconventional oils, like myrtle oil, could represent a sustainable approach to increase its oxidative stability during storage. Full article

(1) Background: The invasive ambrosia beetle Xylosandrus compactus (Coleoptera, Curculionidae, Scolytinae) poses an increasing risk of being introduced into new environments, mostly unintentionally, via wood products, live plants, and wood packaging materials. It is already spreading across Europe and causing growing concern due to its destructive behavior and by infesting a wide range of woody plants. The aim of this research is to identify X. compactus in Croatia and compile a list of recorded host plants. (2) Methods: Fieldwork was conducted through the assessment of beetle presence and infestation levels on host plants showing visible symptoms of attack, as well as through sampling of the beetles. Adult specimens of bark beetles were examined under a microscope, and molecular analysis was done. DNA was extracted from three randomly chosen individuals. The sequences were compared using the BLAST tool in the NCBI GenBank database. (3) Results and Conclusions: X. compactus was confirmed as a new record in Croatia, infesting laurel (Laurus nobilis), holm oak (Quercus ilex), laurestine (Viburnum tinus), olive (Olea sp.), myrtle (Myrtus communis), strawberry tree (Arbutus unedo), and pittosporum (Pittosporum tobira). Full article

The rising global focus on healthy lifestyles and environmental sustainability has prompted interest in repurposing plant-based by-products for health benefits. With increasing life expectancy, the incidence of neurodegenerative diseases—characterized by complex, multifactorial mechanisms such as abnormal protein aggregation, mitochondrial dysfunction, oxidative stress, and inflammation—continues to grow. Medicinal plants, with their diverse bioactive compounds, offer promising therapeutic avenues for such conditions. Myrtus communis L., a Mediterranean plant primarily used in liquor production, generates significant waste rich in antioxidant and anti-inflammatory properties. This study explores the neuroprotective potential of Myrtus berry by-products in a cellular model of neurodegeneration. Using PC12 cells exposed to 6-hydroxydopamine (6-OHDA), we assessed cell viability via MTT assay and measured reactive oxygen species (ROS) production using DCFDA fluorescence. Additionally, we analyzed the expression of genes linked to oxidative stress and neuronal function, including AChE, PON2, Grin1, Gabrd, and c-fos, by RT-PCR. Our findings reveal that Myrtus extract significantly protects against 6-OHDA-induced cytotoxicity, reduces ROS levels, and modulates the expression of key stress-related genes, underscoring its potential as a neuroprotective agent. These results highlight the therapeutic promise of Myrtus extracts in mitigating neurodegenerative processes, paving the way for future interventions. Full article

This research paper investigates the phytochemical profile, antioxidant activity, antidiabetic potential, and antibacterial activity of Myrtus communis berries. Two extraction methods were employed to obtain the extracts: solid–liquid ultrasound-assisted extraction (UAE) and supercritical fluid extraction (SFE). The extracts were characterized using spectrophotometric methods and Reversed-Phase High-Performance Liquid Chromatography (RP-HPLC). The UAE extract exhibited higher total flavonoid and anthocyanin content, while the SFE extract prevailed in total phenolic content and antioxidant activity in the DPPH radical screening assay. RP-HPLC characterization identified and quantified several polyphenolic compounds. In the UAE extract, epigallocatechin was found in a concentration of 2656.24 ± 28.15 µg/g dry weight (DW). In the SFE extract, cafestol was the identified compound with the highest content at a level of 29.65 ± 0.03 µg/g DW. Both extracts contained several anthocyanin compounds, including cyanidin 3-O-glucoside chloride, cyanidin-3-O-rutinoside chloride, malvidin-3-O-glucoside chloride, pelargonidin 3-O-glucoside chloride, peonidin 3-O-glucoside chloride, and peonidin-3-O-rutinoside chloride. The antidiabetic potential was evaluated in vitro by measuring the inhibition of α-amylase from porcine pancreas (type I-A). The results highlighted the ability of myrtle berry extracts to inhibit α-amylase enzymatic activity, suggesting its potential as an alternative for controlling postprandial hyperglycemia. The UAE extract showed the lowest IC50 value among the two extracts, with an average of 8.37 ± 0.52 µg/mL DW. The antibacterial activity of the extracts was assessed in vitro against Bacillus spp., Escherichia coli, and Staphylococcus aureus using the disk diffusion method. Both myrtle berry extracts exhibited similar antibacterial activity against the tested bacterial strains. The results support further investigation of myrtle berries extracts as a potential ingredient in functional food formulation, particularly due to its antioxidant, antidiabetic, and antibacterial properties. Full article

Background/Objectives: The rose myrtle Rhodomyrtus tomentosa is a medicinal plant used in traditional Asian medicine. The active compound in R. tomentosa leaf extracts is rhodomyrtone, a chiral acylphloroglucinol. Rhodomyrtone exhibits an impressive breadth of activities, including antibacterial, antiviral, antiplasmodial, immunomodulatory, and anticancer properties. Its antibacterial properties have been extensively studied. Methods: We performed a comprehensive literature review on rhodomyrtone and summarized the current knowledge about this promising acylphloroglucinol antibiotic and its diverse functions in this review. Results: Rhodomyrtone shows nano to micromolar activities against a broad range of Gram-positive pathogens, including multidrug-resistant clinical isolates, and possesses a unique mechanism of action. It increases membrane fluidity and creates hyperfluid domains that attract membrane proteins prior to forming large membrane vesicles, effectively acting as a membrane protein trap. This mechanism affects a multitude of cellular processes, including cell division and cell wall synthesis. Additionally, rhodomyrtone reduces the expression of inflammatory cytokines, such as TNF-α, IL-17A, IL1β, and IL8. Generally showing low toxicity against mammalian cells, rhodomyrtone does inhibit the proliferation of cancer cell lines, such as epidermal carcinoma cells. The primary mechanism behind this activity appears to be the downregulation of adhesion kinases and growth factors. Furthermore, rhodomyrtone has shown antioxidant activity and displays cognitive effects, such as decreasing depressive symptoms in mice. Conclusions: Rhodomyrtone shows great promise as therapeutic agent, mostly for antibacterial but also for diverse other applications. Yet, bottlenecks such as resistance development and a better understanding of mammalian cell toxictiy demand careful assessment. Full article

Plants are an immense source of drugs, and 50% of modern pharmacopeia has a plant origin. With increasing life expectancy in humans, many age-related degenerative diseases converge on oxidative cellular stress pathways. This provides an opportunity to develop broad treatments by targeting the cause of common pathologic cell degeneration. Toxicological effects can be readily assessed in a live animal model system to establish potential fauna for clinical use. Here, we characterized and evaluated the antioxidant potential and toxicological effects of anise myrtle (Syzygium anisatum) and lemon myrtle (Backhousia citriodora) leaves. Using zebrafish larvae, a model for high-throughput pre-clinical in vivo toxicology screening, we identified safe levels of extract exposures for development of future therapeutics. The antioxidant capacity and toxicity were very similar in these two myrtles. The LC₅₀-96h for anise myrtle was 284 mg/L, and for lemon myrtle, it was 270 mg/L. These measurements are comparable to ongoing studies we are performing using the same criteria in zebrafish, which allow for robust testing and prioritization of natural fauna for drug development. Full article

Preparation of myrtle liqueur through ethanol-based extraction is a widely employed methodology. Nevertheless, optimization of existing processes is possible, especially through a modern statistical multivariate approach. In this context, a Design of Experiments (DoE) approach was used to quantitatively assess for the first time the effect of the time, ethanol concentration, temperature, and the ratio between the Myrtus communis berries’ weight and the extractant volume (v/w) on the amounts of anthocyanins, volatile compounds and dry residues in the liqueur. The kinetic profile relative to the volatile fraction variation during the process was described by gas chromatography (GC), while spectrophotometric analysis allowed quantification of the total anthocyanins and total polyphenols. Multiple response analysis showed that the maximum efficiencies in terms of the considered parameters (desirability function) were reached by setting the temperature to 25 °C and the ethanol percentage to 96% after 20 days of processing. Some hints as to the chemical instability and not negligible sensitivity of anthocyanins in relation to the experimental conditions for longer extraction times were also observed. The statistical model represents a novel tool for industrial production of myrtle liqueur. Full article

Phenolic compounds, present in plants, provide substantial health advantages, such as antioxidant and anti-inflammatory properties, which enhance cardiovascular and cognitive well-being. Australia is enriched with a wide range of plants with phytopharmacological potential, which needs to be fully elucidated. In this context, we analyzed leaves of aniseed myrtle (Syzygium anisatum), lemon myrtle (Backhousia citriodora), and cinnamon myrtle (Backhousia myrtifolia) for their complex phytochemical profile and antioxidant potential. LC-ESI-QTOF-MS/MS was applied for screening and characterizing these Australian myrtles’ phenolic compounds and the structure–function relation of phenolic compounds. This study identified 145 and quantified/semi-quantified 27 phenolic compounds in these Australian myrtles. Furthermore, phenolic contents (total phenolic content (TPC), total condensed tannins (TCT), and total flavonoids (TFC)) and antioxidant potential of phenolic extracts from the leaves of Australian myrtles were quantified. Aniseed myrtle was quantified with the highest TPC (52.49 ± 3.55 mg GAE/g) and total antioxidant potential than other selected myrtles. Catechin, epicatechin, isovitexin, cinnamic acid, and quercetin were quantified as Australian myrtles’ most abundant phenolic compounds. Moreover, chemometric analysis further validated the results. This study provides a new insight into the novel potent bioactive phenolic compounds from Australian myrtles that could be potentially useful for functional, nutraceutical, and therapeutic applications. Full article

Background: Myrtle (Myrtus communis L.) is a coastal Mediterranean aromatic medicinal plant rich in essential oil components, flavonoids, and phenolic acids. Studies highlight the potential health benefits of myrtle bioactive compounds with antioxidant and antiproliferative properties. Since limited research exists on myrtle fruit’s lipid fraction, the aim of this study was to apply supercritical CO₂ extraction to obtain bioactive compounds from myrtle berries focusing on the fatty acids, sterols, and essential oils. Methods: The optimization of the supercritical CO₂ extraction of myrtle fruit using CO₂ as solvent was carried out using the response surface methodology with Box–Behnken experimental design. The following conditions were tested: temperature (40, 50, and 60 °C), pressure (200, 300, and 400 bar), and flow rate (20, 30, and 40 g min⁻¹) on the yield of lipid extract as well as on the yield of fatty acids, phytosterols, and volatiles present in the extract and constituting its bioactive potential. Results: In the extracts examined, 36 fatty acids, 7 phytosterols, and 13 volatiles were identified. The average yield of the extract was 5.20%, the most abundant identified fatty acid was essential cis-linolenic acid (76.83%), almost 90% of the total phytosterols were β-sitosterol (12,465 mg kg⁻¹), while myrtenyl acetate (4297 mg kg⁻¹) was the most represented volatile compound. The optimal process conditions obtained allow the formulation of extracts with specific compositions. Full article

Myrtle rust is a very damaging disease, caused by the fungus Austropuccinia psidii, which has recently arrived in New Zealand and threatens the iconic tree species pōhutukawa (Metrosideros excelsa). Canopy-level hyperspectral and thermal images were taken repeatedly within a controlled environment, from 49 inoculated (MR treatment) and 26 uninoculated (control treatment) pōhutukawa plants. Measurements were taken prior to inoculation and six times post-inoculation over a 14-day period. Using indices extracted from these data, the objectives were to (i) identify the key thermal and narrow-band hyperspectral indices (NBHIs) associated with the pre-visual and early expression of myrtle rust and (ii) develop a classification model to detect the disease. The number of symptomatic plants increased rapidly from three plants at 3 days after inoculation (DAI) to all 49 MR plants at 8 DAI. NBHIs were most effective for pre-visual and early disease detection from 3 to 6 DAI, while thermal indices were more effective for detection of disease following symptom expression from 7 to 14 DAI. Using results compiled from an independent test dataset, model performance using the best thermal indices and NBHIs was excellent from 3 DAI to 6 DAI (F1 score 0.81–0.85; accuracy 73–80%) and outstanding from 7 to 14 DAI (F1 score 0.92–0.93; accuracy 89–91%). Full article

This research aimed to understand the effects of adding myrtle plant extract obtained from its leaves (MPEL) and roots (MPER) to the milk fed to suckling female Holstein calves, focusing on performance, reproduction, selected blood parameters and immune response. The 50 Holstein female calves, one week of age, were divided into five groups: one group received no plant extract (Control), while the others were supplemented with myrtle plant extracts at doses of 25 mL/day leaf extract (MPEL-25), 25 mL/day root extract (MPER-25), 50 mL/day leaf extract (MPEL-50) and 50 mL/day root extract (MPER-50) for each calf in each treatment group. The extracts were given along with the milk to the experimental groups for 60 days, and for an additional 12 days post-weaning. The results reveal that the feed consumption and live weights increased significantly. Significantly higher leukocyte counts were observed in the 50 mL/head × day myrtle groups, and a higher IgG concentration was also noted in the MPER-50 group compared to the other groups. The serum non-esterified fatty acid (NEFA) concentration significantly decreased in the MPEL-50 and MPER-50 groups, whereas the betahyrdoxy butyric acid (BHBA) concentration increased and the serum glucose concentration significantly decreased with myrtle supplementation. In conclusion, it was determined that the performance, immune system and negative energy balance compensation of female Holstein calves were positively affected by administering extracts obtained from the leaves and roots of the Myrtus communis L. plant at dose levels of 25 and 50 mL/head × day for 72 days, without causing any side effects. Full article