The increased amount of melanin leads to skin disorders such as age spots, freckles, melasma and malignant melanoma. Tyrosinase is known to be the key enzyme in melanin production. Plants and their extracts are inexpensive and rich resources of active compounds that can be utilized to inhibit tyrosinase as well as can be used for the treatment of dermatological disorders associated with melanin hyperpigmentation. Using in vitro tyrosinase inhibitory activity assay, extracts from 13 plant species from Brazilian Cerrado were evaluated. The results showed that Pouteria torta and Eugenia dysenterica extracts presented potent in vitro tyrosinase inhibition compared to positive control kojic acid. Ethanol extract of Eugenia dysenterica leaves showed significant (p<0.05) tyrosinase inhibitory activity exhibiting the IC50 value of 11.88 µg/mL, compared to kojic acid (IC50 value of 13.14 µg/mL). Pouteria torta aqueous extract leaves also showed significant inhibitory activity with IC50 value of 30.01 µg/mL. These results indicate that Pouteria torta and Eugenia dysenterica extracts and their isolated constituents are promising agents for skin-whitening or antimelanogenesis formulations.
The use of natural oils in topical pharmaceutical preparations has usually presented safe agents for the improvement of human health. Based on research into the immense potential of wound management and healing, we aimed to validate the use of topical natural products by studying the ability of the essential oil of Eugenia dysenterica DC leaves (oEd) to stimulate in vitro skin cell migration. Skin cytotoxicity was evaluated using a fibroblast cell line (L929) by MTT assay. The oil chemical profile was investigated by GC-MS. Moreover, the inhibition of lipopolysaccharide (LPS) induced nitric oxide (NO) production in the macrophage cell line (RAW 264.7) tested. The Chick Chorioallantoic Membrane (CAM) assay was used to evaluate the angiogenic activity and irritating potential of the oil. The oEd induces skin cell migration in a scratch assay at a concentration of 542.2 µg/mL. α-humulene and β-caryophyllene, the major compounds of this oil, as determined by GC-MS, may partly explain the migration effect. The inhibition of nitric oxide by oEd and α-humulene suggested an anti-inflammatory effect. The CAM assay showed that treatment with oEd ≤ 292 µg/mL did not cause skin injury, and that it can promote angiogenesis in vivo. Hence, these results indicate the feasibility of the essential oil of Eugenia dysenterica DC leaves to developed dermatological products capable of helping the body to repair damaged tissue.
Trabalhos taxonômicos e filogenéticos têm utilizado informações anatômicas e para contribuir com estes estudos examinaram-se cortes paradérmicos e transversais da porção mediana foliar de Campomanesia adamantium (Camb.) O. Berg, Myrcia cordiifolia DC., M. decrescens O. Berg e M. torta D.C. Os caracteres anatômicos foram comparados com os de outras espécies descritas na literatura. São características comuns às quatro espécies examinadas: epiderme uniestratificada, tricomas unicelulares, folhas hipoestomáticas, estômatos paracíticos, cavidades secretoras em ambas as faces, mesofilo dorsiventral e nervura mediana com feixes bicolaterais. Destacam-se os seguintes caracteres úteis para a taxonomia da família: formato das células comuns da epiderme, tricomas dibraquiados ou não, camadas celulares incolores subepidérmicas e formato da nervura mediana. O formato e número das células teto das glândulas foliares têm utilidade taxonômica. O exame de 144 exsicatas evidenciou que a glabrescência é um fenômeno comum. A queda dos tricomas pode ser devido à sua base estreita e à ausência de célula pedal nos mesmos. Analisaram-se os caracteres à luz de estudos filogenéticos recentes e do ponto de vista ecológico, destacando a hipótese relacionada às células epidérmicas com possível função de célula de transferência. As características anatômicas forneceram dados para análises comparativas mais amplas entre os táxons de Myrtaceae e possibilitaram a construção de um cladograma, onde espécies de Leptospermum e Eucalyptus ocuparam posição basal, em consonância com filogenias relatadas na literatura.
11 July 2016 in BMC Complementary and Alternative Medicine
Medicinal plants have traditionally been used in many parts of the world as alternative medicine. Many extracts and essential oils isolated from plants have disclosed biological activity, justifying the investigation of their potential antimicrobial activity. In this study, the in vitro antifungal activity of six Brazilian Cerrado medicinal plant species were evaluated against clinically relevant Candida species. The crude extract plants were evaluated against American Type Culture Collection (ATCC) standard strains of Candida spp. using disk diffusion method and determining the minimum inhibitory concentration (MIC). The chemical study results were confirmed by HPLC method. All six plant species showed antifungal activity. Among the species studied, Eugenia dysenterica and Pouteria ramiflora showed significant inhibitory activity against C. tropicalis at lowest MIC value of 125 and 500 μg/disc, respectively. The Eugenia dysenterica also disclosed MIC value of 125 μg/disc against C. famata, 250 μg/disc against C. krusei and 500 μg/disc against C. guilliermondii and C. parapsilosis. Pouteria torta, Bauhinia rufa, Erythroxylum daphnites and Erythroxylum subrotundum showed activity against the yeast strains with MIC value of 1000 μg/disc. The chemical study of the most bioactive extracts of Eugenia dysenterica and Pouteria ramiflora revealed catechin derivatives and flavonoids as main components. All six evaluated plant species showed good antifungal potential against several Candida strains. However, E .dysenterica and P. ramiflora showed the higher inhibitory effect against the non-albicans Candida species. Our results may contribute to the continuing search of new natural occurring products with antifungal activity.
2 June 2016 in Botanical Journal of the Linnean Society