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.

Óleos essenciais no tratamento de dermatozoonoses – uma revisão de literatura

O uso indiscriminado de medicamentos tem representado uma das maiores ameaças à Saúde Única, haja vista sua atuação na resistência antimicrobiana e seus impactos ao meio ambiente. Assim, busca-se como alternativa sustentável a esses fármacos, os óleos essenciais, substâncias com diversas atividades terapêuticas, destacando a eficácia no tratamento de dermatopatias de origem zoonótica, a exemplo escabiose canina, esporotricose, dermatofitose e leishmaniose tegumentar americana. O presente trabalho tem por objetivo realizar revisão bibliográfica acerca do emprego de óleos essenciais na medicina veterinária, destacando-se o tratamento das dermatopatias de origem zoonótica. Foi demonstrado o efeito acaricida, fungicida e fungistático dos óleos essenciais de Melaleuca alternifolia, Cedrus deodara, Azadirachta indica, Myrtus communis, Thymus vulgaris, Rosmarinus officinalis, Lavandula angustifolia, Cinnamomum cassia, Eugenia uniflora e Plectranthus amboinicus. As dermatozoonoses apresentam crescente resistência a antifúngicos e antibióticos comerciais, o emprego de terapias alternativas utilizando óleos essenciais se faz relevante de forma a amenizar essa resistência, e proporcionar melhoria na sanidade dos animais. Diante disso, dentre os estudos avaliados é demonstrado que os óleos essenciais de Melaleuca alternifolia, Cedrus deodara, Azadirachta indica, Myrtus communis, Thymus vulgaris, Rosmarinus officinalis, Lavandula angustifolia, Cinnamomum cassia, Eugenia uniflora e Plectranthus amboinicus apresentam resultado in vitro satisfatórios na terapêutica de dermatozoonoses de importância clínica, contudo, se faz necessário a realização de estudos in vivo para verificar a eficácia destes compostos, realizando-se um monitoramento de sua ação mediante as barreiras fisiológicas e metabolismo dos animais.

Boosted Antioxidant Effect Using a Combinatory Approach with Essential Oils from Origanum compactum, Origanum majorana, Thymus serpyllum, Mentha spicata, Myrtus communis, and Artemisia herba-alba: Mixture Design Optimization

Several studies have demonstrated the possible synergistic effect as an effective strategy to boost the bioactivity of essential oils. Using this framework, this study was conducted to effectively establish the ideal combination of six essential oils from different plants (Origanum compactum, Origanum majorana, Thymus serpyllum, Mentha spicata, Myrtus communis, and Artemisia herba-alba) that would express the best antioxidant activity. Each mixture was optimized using a mixture design approach to generate the most effective blend. The 2,2-diphenyl-1-picrylhydrazyl radical scavenging method was used as a reference method to assess the antioxidant activity. Each essential oil’s composition was identified using the GC/MS method. The single essential oil activities demonstrated variable antioxidant effects, and following the mixture design approach, the optimal antioxidant blend was revealed, as two mixtures demonstrated the best antiradical activity with 79.46% obtained with the mixture of O. majorana (28%) and M. spicata (71%) and 78.8% obtained with the mixture O. compactum (64%), O. majorana (13%), and T. serpyllum (21%). This study proposes a practical way to elaborate mixtures in the search for a boosting effect that can be oriented for the food or pharmaceutical industry.

Myrtus Communis Leaf Extract - A Source of Secondary Metabolites Exhibiting Anticancer and Antimycobacterial Activities

Background: Plant-derived products or extracts are widely used in folk/traditional medicine to treat several, infections, ailments, or disorders. A notable therapeutic herb Myrtus communis, worldwide utilized in the traditional medication for centuries, is an evergreen aromatic and medicinal plant of the Mediterranean region. Materials and methods: The SulphoRhodamine-B assay and DNA flow cytometry were used to investigate the proliferation and subsequent distribution of cells among different phases of the cell cycle. Annexin V-FITC/PI staining coupled with flow cytometry was used to analyze apoptosis and necrosis of the cancer cells. Western blotting detected the expression of pro- and anti-apoptotic proteins. Zone of inhibition and MIC were determined by well diffusion method and microplate alamar blue assay, respectively. Biofilm formation was studied by crystal violet method. For statistical analysis, a two-tailed Student’s t-test of GraphPad Prism 6.0 was used.Results: In this study, the secondary metabolites of M. communis leaves extracted in ethanol showed the highest cytotoxicity and thus the greatest anticancer effects against diverse cancer cell lines of the breast (MCF-7), liver (HepG2), cervix (HeLa), and colon (HCT116) (IC50; ranging from 33 to 83 mg/ml). The cancer cells arrested in the G1 phase of the cell cycle undergo apoptosis. The induction of the latter is mediated by activation of the intrinsic mitochondrial pathway. Furthermore, the extract showed a strong growth inhibitory effect (zone of inhibition; 20.3±1.1 - 26.3±2.5 mm, MIC; 4.88 - 312.5 µg/ml, and MBC; 39.07 - 1250 μg/ml) against several rapid and slow-growing mycobacterial strains that cause tuberculosis and several other mycobacterial infections. The biofilm formation in BSL2 microorganisms, M. smegmatis and S. aureus, is strongly inhibited by the extract. Conclusion: These results suggest that M. communis leaf extract is a potential source of secondary metabolites, which could be developed further as potential anti-cancer and anti-mycobacterial agents to treat diverse types of cancers and mycobacterial infections.