The genetic diversity of 29 endophytic bacterial strains isolated from apoplastic sap of the medullary parenchym of the stem of healthy sugarcane plants grown in Cuba was analysed by Two Primers-Ramdom Amplified Polymorphic DNA fingerprinting (TP-RAPD) and 16S rRNA gene sequencing. The strains were distributed into 17 groups on the basis of their TP-RAPD patterns, and a representative strain from each group was subjected to 16S rRNA gene sequencing. Analysis of these sequences showed that the isolates belong to a wide variety of phylogenetic groups being closely related to species of genera Bacillus and Staphylococcus from Firmicutes, Microbacterium, Micrococcus and Kokuria from Actinobacteria, Rhizobium and Gluconacetobacter from alpha -Proteobacteria, Comamonas and Xanthomonas from beta-Proteobacteria, and Acinetobacter and Pantoea from gamma-Proteobacteria. These results show the complexity of the bacterial populations present in inner tissues of sugarcane, and indicate the interest and relevance of the studies on microbial diversity to improve our knowledge on the plant endophytic bacterial communities.

The structure of the new withanolide:acnistin B, isolated from Dunalia solanacea, has been established by NMR experiments and the immunosuppressive effects of acnistins A, B and E on human lymphocytes have been measured.

La especie Licania platypus, localmente conocida como “sonzapote” se encuentra ampliamente distribuida en países tropicales. Tradicionalmente, en América Central se han utilizado diferentes partes de la planta para diversos problemas de salud, especialmente gastrointestinales. Objetivo: Investigar la posible actividad antiulcerosa gástrica del extracto etanólico de hojas de Licania platypus. Métodos: Las lesiones gástricas fueron inducidas por los modelos de etanol e indometacina. También, se evaluó el extracto con el modelo modificado de Shay. El extracto se administró por vía oral y se midió el área dañada. Además, se analizaron otros parámetros en el modelo de ligadura pilórica. Resultados: La administración oral de una dosis única del extracto (500 mg/kg) redujo significativamente el área de las lesiones gástricas (p < 0.05) en los modelos de inducción de etanol e indometacina. Además, se observó un incremento significativo en la secreción de moco gástrico en el modelo modificado de Shay (p < 0.05). Conclusión: El extracto etanólico de Licania platypus ejerce un efecto gastroprotector en diferentes modelos de inducción de úlceras agudas. Este trabajo brinda la primera evidencia de especies pertenecientes al género Licania con actividad gastroprotectora y permite promover la realización de estudios para elucidar un mecanismo de acción específico.

Objective: Identify the types of nanoparticles used in dermocosmetics and their main applications. Methods: A bibliographic review was carried out in the databases Google Scholar, and PubMed, as well as databases subscribed to the system of libraries, documents, and information of the Universidad de Costa Rica such as ScienceDirect, Elsevier, EBSCO, MEDLINE, Clinical-Key, among others. The search was conducted in both English and Spanish. Conclusion: Nanotechnology in the cosmetic industry has been an area that has grown exponentially in recent years. Various types of nanoparticles are used in different skincare applications in the cosmetics industry; however, much research remains to be done on the safety and toxicity of their use for humans and the environment.

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