Myrtus communis leaves: source of bio - actives, traditional use, their biological properties, and prospects / Hojas de Myrtus communis: fuente de bioactivos, uso tradicional, sus propiedades biológicas y perspectivas

Myrtus communis L., commonly known as true myrtle, is a medicinal plant native to the Mediterranean area. Since ancient times, the inhabitant s of this area have been using it for its cultural and medicinal properties. Because of the vast diversity of biomolecules in its aerial parts, it exhibits several biological properties, including antioxidant, antimicrobial, and anticancer properties. This review retrospect the research on the source, biological activities with empirical evidence, chemical composition, applications, and cellular targets of extracts and essential oils obtained from M. communis leaves, which provides a perspective for further studies on the applications and formulations of extract and EO of M. communis leaves. The efficacy of constituents' individually, in association with other bioactive constituents, or in combination with available commercial drugs would provide insights in to the development of these bio - actives as future drugs and their evolving future potential applications in the pharmaceutical, food, and aroma industries.

Myrtus communis L., comúnmente conocido como arrayán verdadero, es una planta medicinal originaria de la zona mediterránea. Desde la antigüedad, los habitantes de esta zona lo utilizan por sus propiedades culturales y medicinales. Debido a la gran div ersidad de biomoléculas en sus partes aéreas, exhibe varias propiedades biológicas, incluidas propiedades antioxidantes, antimicrobianas y anticancerígenas. Esta revisión retrospectiva de la investigación sobre la fuente, las actividades biológicas con evi dencia empírica, la composición química, las aplicaciones y los objetivos celulares de los extractos y aceites esenciales obtenidos de las hojas de M. communis , lo que brinda una perspectiva para futuros estudios sobre las aplicaciones y formulaciones de l os extractos y EO de M. communis . La eficacia de los componentes individualmente, en asociación con otros componentes bioactivos o en combinación con medicamentos comerciales disponibles proporcionaría información sobre el desarrollo de estos bioactivos co mo medicamentos futuros y sus futuras aplicaciones potenciales en las industrias farmacéutica, alimentaria y aromática

Bioactivity of Myrtus communis from the Montenegro coastline / Bioactividad de Myrtus communis del litoral de Montenegro

Although numerous studies have demonstrated the biomedical potential of Myrtus communis L., (Myrtaceae) data on myrt le from Montenegro are scarce. T o evaluate antioxidant, antimutagenic and antibacterial activity of myrtle methanolic extracts. Antioxidant activity was evaluated by measuring free radicals scavenging activity, reducing power and enzyme inhibition. The strongest scavenging activity was towards DPPH radical ( 2,2 - diphenyl - 1 - picry lhydrazyl) (IC 50 1.69 - 2.25 mg/mL) and superoxide anion (IC 50 0.56 to 0.88 mg/mL), followed by high reducing power (428 - 472 mgAA/g.DE) and inhibition of XOD (IC 50 0.308 - 0.6261mg/mL). Antimutagenic activity was evaluated in reverse mutation assays with Esche richia coli WP2 oxyR mutant IC202 and deficient in the induction of antioxidant enzymes. The myrtle extracts strongly inhibited mutagenesis induced by t - BOOH, reaching 70% at the highest concentration applied. Antimicrobial activity was examined on eight different bacterial strains. Gram - positive bacteria, S. epidermis , S. aureus and M. flavus demonstrated the highest sensitivity towards extracts (MICs 4.5 - 9 mg/mL), but significantly lower towards essential oil (MIC 0.42 - 3.32 mg/mL).

Aunque numerosos estudios han demostrado el potencial biomédico de Myrtus communis L., (Myrtaceae), los datos sobre el mirto de Montenegro son escasos. E valuar la actividad antioxidante, antimutagéni ca y antibacteriana de extractos metanólicos de mirto. La actividad antioxidante se evaluó midiendo la actividad de eliminación de radicales libres, el poder reductor y la inhibición enzimática. La actividad secuestrante más fuerte fue hacia DPPH radical ( IC 50 1.69 - 2.25 mg/mL) y radicales de anión superóxido (IC 50 0.56 a 0.88 mg/mL), seguido de alto poder reductor (428 - 472 m gAA/g.DE) e inhibición de XOD (I C 50 0,308 - 0,6261 mg/m L ). La actividad antimutagénica se evaluó en ensayos de mutación inversa con Esche richia coli WP2 oxyR mutante IC202 y deficiente en la inducción de enzimas antioxidantes. Los extractos de mirto inhibieron fuertemente la mutagénesis inducida por t - BOOH, alcanzando el 70% a la mayor concentración aplicada. La actividad antimicrobiana se examinó en octo cepas bacterianas diferentes. Las bacterias grampositivas, S. epidermis , S. aureus y M. flavus demostraron la sensibilidad más alta hacia los extractos (MIC 4.5 - 9 mg/mL), pero significativamente más baja hacia el aceite esencial (MIC 0.42 - 3 .32 mg/mL). Los resultados muestran la gran perspectiva nutrafarmacéutica de la especie montenegrina Myrtus communis .

Surveying potentially antagonistic fungi to myrtle rust (Austropuccinia psidii) in Brazil: fungicolous Cladosporium spp.

The myrtle rust (MR), caused by Austropuccinia psidii, is a worldwide threat to the cultivated and wild Myrtaceae. Originally from the neotropics, it has spread to North America, Africa, and Asia and has reached geographically isolated areas in the Pacific and Australasia. It is attacking native species in those new ranges and is still spreading and causing great concern for the damage caused to endemic Myrtaceae, and to the environment. Classical biological control is regarded as the most sustainable management option for mitigating such biological invasions. However, there are no examples of introductions of host-specific co-evolved natural enemies of plant pathogens, from their native range, as a management strategy for plant pathogens. In order to explore this neglected approach, a survey of potential fungal natural enemies of A. psidii was initiated recently in the state of Minas Gerais (Brazil). Several purported mycoparasites have been collected from A. Psidii pustules formed on myrtaceous hosts. This included some isolates of dematiaceous fungi recognized as having a Cladosporium-like morphology. Here we present the results of the investigation aimed at elucidating their identity through a polyphasic taxonomic approach. Besides morphological and cultural features, molecular analyses using sequences of translation elongation factor 1-α (EF1) and actin (ACT) were performed. The combination of data generated is presented herein and placed all Cladosporium-like isolates in six species of Cladosporium, namely, Cladosporium angulosum, C. anthropophilum, C. bambusicola, C. benschii, C. guizhouense, and C. macadamiae. None of these have ever been recorded in association with A. psidii. Now, with the identification of these isolates at hand, an evaluation of biocontrol potential of these fungi will be initiated. In contrast with the ready finding of fungicolous (possibly mycoparasitic) fungi on MR in this study, no evidence of those was recorded from Australasia until now.

The usefulness of a dermocosmetic containing Myrtus communis extract and azelaic acid for maintenance phase of adult female acne: Results from a randomized exploratory investigator-blinded comparative study.

BACKGROUND: Acne is a very common condition. Currently, there are relatively few studies available to help guidance-based decisions for its long-term management, especially studies with cosmetic care products. We have developed a skin care product dedicated to adult female acne. OBJECTIVES: Evaluate the efficacy and tolerance of the test product containing Myrtus communis extract and azelaic acid compared with a light moisturizing cream (LCM) in adult females in the acne maintenance phase. METHODS: A clinical study was conducted as a Brazilian, multicentre, randomized, investigator-blinded trial in adult females with clear or almost clear facial acne after anti-acne treatment. The test group (26 subjects) applied the test product and the comparative product group (27 subjects) applied LCM. Both groups applied the products twice daily on the whole face. Subjects were evaluated every 4 weeks over 16 weeks. Efficacy was evaluated according to acne relapse; Investigator's Global Assessment (IGA); acne lesions counting; AcneQoL questionnaire; Subject Global change Assessment (SGA) of acne severity; and the number of Post-Inflammatory Hyperpigmentation (PIH) and Post-Inflammatory Erythema (PIE) lesions. Tolerance was assessed according to a 5-point scale. RESULTS: Over 16 weeks, the number of acne relapse was more than double in the comparator compared to the test product group (eight subjects vs. three subjects respectively). There was no statistical difference in the evolution of the mean IGA from baseline between the two groups; however, 85% of subjects were assessed as clear or almost clear in the test product group and 67% in the comparative group. CONCLUSIONS: This study demonstrated the effectiveness topical application of the test product compared to LCM on acne severity in the maintenance phase of adult female acne. Efficacy results after 16 weeks suggested a trend to limit acne relapses and a benefit of the test product in maintaining long-term remission.

Monocyclic Components and Photosynthetic Damage Caused by Myrtle Rust in Guava Leaves.

Austropuccinia psidii, the causal agent of myrtle rust, was, for many years, restricted to the Americas, but since reaching Hawaii in 2005, the pathogen has expanded its global range exponentially. In Brazil, myrtle rust is the main fungal disease in guava plants. Despite this, there are few studies on guava rust epidemiology. The objectives of this study were to quantify the monocyclic components of rust and to evaluate the photosynthetic damage caused by A. psidii in young and old leaves of 'Paluma' guava. The monocyclic components of guava rust and gas exchange in healthy or inoculated (105 ml-1 urediniospores of A. psidii) leaves were quantified over time. Additionally, young leaves were inoculated with varying concentrations of A. psidii inoculum, and leaf gas exchange and chlorophyll fluorescence were measured at 25 days postinoculation. The relationship between the relative CO2 assimilation of a diseased leaf (Px) and a healthy leaf (Po) is related to disease severity (x) by Px/Po = (1 - x)ß. The density of lesions, disease severity, and urediniospore production were high in young leaves, averaging 58 lesions cm-2, 50% leaf area diseased, and 2.5 × 104 urediniospores per lesion, respectively. Rust symptoms were not observed in old leaves, and resistance to infection did not cause any photosynthetic cost to these leaves. On young leaves, ß was 2.13, indicating a reduction on CO2 assimilation at green tissues from symptomatic leaves. Our data revealed that photosynthesis reduction in diseased guava leaves was caused by biochemical and photochemical damage rather than by stomatal limitation.

Efficacy of Fungicides Applied for Protectant and Curative Activity Against Myrtle Rust.

Myrtle rust, caused by the pathogen Austropuccinia psidii, affects species of the Myrtaceae, many of which are endemic to Australia and New Zealand. Originating from South America, A. psidii is now present in both countries, necessitating effective chemical control for disease management. Using an artificial inoculation protocol, the efficacy of eight fungicides (tebuconazole/trifloxystrobin, cyproconazole/azoxystrobin, fosetyl aluminum, triforine, triadimenol, oxycarboxin, copper, and tebuconazole) applied as curative or protectant treatments was tested on two native New Zealand species (Lophomyrtus × ralphii and Metrosideros excelsa). The impacts of rate (×2), frequency (single or double), and timing (pre- or postinfection) of fungicide application were investigated. Overall, the most effective fungicides tested across both species were those that included a demethylation inhibitor and strobilurin mix, notably tebuconazole/trifloxystrobin (Scorpio) and cyproconazole/azoxystrobin (Amistar Xtra). These fungicides significantly reduced infection of host plants relative to the water control. Timing of application significantly affected bioefficacy, with applications made 7 days before inoculation or 7 days after inoculation being generally the most effective. The rate of fungicide application was not significant for both host species, with few interaction terms showing overall significance. Key findings from this study will set the foundation for further fungicide bioefficacy research conducted to evaluate formulations and adjuvant mixtures, determine suitable application methods for enhanced retention and coverage, and derive optimum application time for effective protection of native and exotic Myrtaceae species in New Zealand.

Gastroprotective effect of (-)-myrtenol against ethanol-induced acute gastric lesions: possible mechanisms.

OBJECTIVES: (-)-Myrtenol is a natural fragrance monoterpenoid structurally related to α-pinene found in diverse plant essential oils. This study was aimed to assess the anti-ulcerogenic potential of (-)-myrtenol against ethanol-induced gastric lesions and to elucidate the underlying mechanism(s). METHODS: Gastroprotective activity of (-)-myrtenol was evaluated using the mouse model of ethanol-induced gastric damage. To elucidate the gastroprotective mechanism(s), the roles of GABA, prostaglandins, nitric oxide and KATP channels were assessed. Besides, the oxidative stress-related parameters and the mucus content in gastric tissues were analysed. KEY FINDINGS: (-)-Myrtenol at oral doses of 25, 50 and 100 mg/kg significantly decreased the severity of ethanol-induced gastric lesions affording gastroprotection that was accompanied by a decrease in the activity of myeloperoxidase and malondialdehyde, an increase in GPx, SOD, and catalase activity in gastric tissues, and with well-maintained normal levels of nitrite/nitrate, gastric mucus and NP-SHs. Pretreatment with GABA-A receptor antagonist flumazenil, the COX inhibitor indomethacin, and NO synthesis inhibitor L-NAME but not with KATP channel blocker glibenclamide significantly blocked the (-)-myrtenol gastroprotection. CONCLUSION: These results provide first-time evidence for the gastroprotective effect of (-)-myrtenol that could be related to GABAA -receptor activation and antioxidant activity.

The genetic diversity of Sardinian myrtle (Myrtus communis L. ) populations

Background: The myrtle (Myrtus communis) is a common shrub widespread in the Mediterranean Basin. Its fruit and leaves exhibit antioxidant, antibacterial and antifungal properties, and are used for their content of essential oils and for their medicinal properties, but most commonly as an ingredient in locally made liquor. The uncontrolled exploitation of natural stands has reduced both the species' geographical coverage and the size of individual populations. The selection of genotypes for controlled cultivation requires a characterization of the genetic diversity present both within and between populations. Results: Genotypic variation was evaluated using ISSR profiling and genetic diversity characterized using standard population genetics approaches. Two major clusters were identified: one capturing all the candidate cultivars selected from various Sardinian localities, and the other wild individuals collected from Asinara, Corsica and Surigheddu. A moderate level of gene flow between the Sardinian and Corsican populations was identified. Discriminant analysis of principal components revealed a level of separation among the wild populations, confirming the population structure identified by the clustering methods. Conclusions: The wild accessions were well differentiated from the candidate cultivars. The level of genetic variability was high. The genetic data were compatible with the notion that myrtle has a mixed pollination system, including both out-pollination by insects and self-pollination. The candidate cultivars are suggested to represent an appropriate basis for directed breeding.

Bioinformatical and in vitro approaches to essential oil-induced matrix metalloproteinase inhibition.

CONTEXT: Essential oils carry diverse antimicrobial and anti-enzymatic properties. OBJECTIVE: Matrix metalloproteinase (MMP) inhibition characteristics of Salvia fruticosa Miller (Labiatae), Myrtus communis Linnaeus (Myrtaceae), Juniperus communis Linnaeus (Cupressaceae), and Lavandula stoechas Linnaeus (Labiatae) essential oils were evaluated. MATERIALS AND METHODS: Chemical compositions of the essential oils were analyzed by gas chromatography-mass spectrometry (GC-MS). Bioinformatical database analysis was performed by STRING 9.0 and STITCH 2.0 databases, and ViaComplex software. Antibacterial activity of essential oils against periodontopathogens was tested by the disc diffusion assay and the agar dilution method. Cellular proliferation and cytotoxicity were determined by commercial kits. MMP-2 and MMP-9 activities were measured by zymography. RESULTS: Bioinformatical database analyses, under a score of 0.4 (medium) and a prior correction of 0.0, gave rise to a model of protein (MMPs and tissue inhibitors of metalloproteinases) vs. chemical (essential oil components) interaction network; where MMPs and essential oil components interconnected through interaction with hydroxyl radicals, molecular oxygen, and hydrogen peroxide. Components from L. stoechas potentially displayed a higher grade of interaction with MMP-2 and -9. Although antibacterial and growth inhibitory effects of essential oils on the tested periodontopathogens were limited, all of them inhibited MMP-2 in vitro at concentrations of 1 and 5 µL/mL. Moreover, same concentrations of M. communis and L. stoechas also inhibited MMP-9. MMP-inhibiting concentrations of essential oils were not cytotoxic against keratinocytes. DISCUSSION AND CONCLUSION: We propose essential oils of being useful therapeutic agents as MMP inhibitors through a mechanism possibly based on their antioxidant potential.

Karyological features of wild and cultivated forms of myrtle (Myrtus communis, Myrtaceae).

Myrtle is an evergreen shrub or small tree widespread throughout the Mediterranean region. In Turkey, both cultivated and wild forms, differing in plant and fruit size and fruit composition, can be found. These differences may have resulted from the domestication of the cultivated form over a long period of time. We investigated whether wild and cultivated forms of myrtle differ in karyological features (i.e., number of somatic chromosomes and relative genome size). We sampled two wild forms and six cultivated types of myrtle. All the samples had the same chromosome number (2n = 2x = 22). The results were confirmed by 4',6-diamidino-2-phenylindole (DAPI) flow cytometry. Only negligible variation (approximately 3%) in relative fluorescence intensity was observed among the different myrtle accessions, with wild genotypes having the smallest values. We concluded that despite considerable morphological differentiation, cultivated and wild myrtle genotypes in Turkey have similar karyological features.