Chemical Characterization and Biological Activities of Jandaíra Stingless Bee Products (Melipona subnitida, Ducke, 1911): A Brief Review.

Melipona subnitida (Ducke, 1911), a species of stingless bee, popularly known as Jandaíra, has a wide distribution in the Brazilian Northeast region, being an important pollinator of the Caatinga biome. This bee produces products such as honey, geopropolis, pollen (saburá) and wax that are traditionally used for therapeutic purposes and some studies report the biological properties, as well as its chemical composition. This review aimed to select, analyze and gather data published in the literature focusing on the chemical profile and bioactivities described for M. subnitida products. Data collection was carried out through the Capes Journal Portal platform, using the following databases: Web of Science, Scopus, and PubMed. Original articles published in English and Portuguese were included, with no time limitation. The chemical composition of M. subnitida products has been investigated through chromatographic analysis, demonstrating the presence of a variety of phenolic compounds, such as flavonoids and phenylpropanoids, among other classes of secondary metabolites. These products also have several biological activities, including antioxidant, healing, antinociceptive, anti-inflammatory, antidepressant, antidyslipidemic, antiobesity, antifungal, antibacterial and prebiotic. Among the biological activities reported, the antioxidant activity was the most investigated. These data show that products derived from the stingless bee M. subnitida have promising bioactive compounds. This review provides useful information about the bioactivities and chemical profile of Melipona subnitida bee products, and a direction for future research, which should focus on understanding the mechanisms of action associated with the already elucidated pharmacological activities, as well as the bioactive properties of the main isolate's constituents identified in the chemical composition of these products.

Evaluation of Elaiophylin extracted from Streptomyces hygroscopicus as a potential inhibitor of the NorA efflux protein in Staphylococcus aureus: An in vitro and in silico approach.

Compounds capable of inhibiting the efflux pump mechanism are a promising alternative against bacterial resistance because, when combined with antibiotics, they can increase the effectiveness of these drugs by inhibiting active efflux. Elaiophylin, derived from Streptomyces hygroscopicus, is a natural antibiotic that exhibits a variety of biological activities, including antibacterial activity. However, its potential as an inhibitor of the bacterial efflux mechanism has not been investigated. This study evaluated the ability of Elaiophylin to inhibit the NorA efflux pump in Staphylococcus aureus strains. Therefore, tests were performed to obtain the Minimum Inhibitory Concentration (MIC) and to verify the ability of Elaiophylin to potentiate the MIC of the antibiotic Norfloxacin and Ethidium Bromide (EtBr), known substrates of NorA efflux. Real-time PCR and molecular docking assays were also performed to assess the potential of Elaiophylin against NorA. The strains SA-1199 (wild type) and SA-1199B (NorA over-expressed) of S. aureus were used for this study. The results showed that Elaiophylin significantly decreased the MIC of Norfloxacin and EtBr, increasing the activity of these substrates against S. aureus, which carries the efflux protein NorA. However, Elaiophylin provided a non-significant reduction in norA gene expression, however, molecular docking demonstrated a high binding affinity between Elaiophylin and NorA efflux protein, indicating that Elaiophylin can act as a potential NorA in S. aureus.