In this study, we investigated the chemical composition, and antioxidant and antibacterial properties of ethanolic extracts of propolis (EEP) from Melipona quadrifasciata quadrifasciata and Tetragonisca angustula. Chemical composition of EEP was determined by colorimetry and chromatographic (HPLC-DAD and UPLC-Q/TOF-MS/MS) analysis. Antimicrobial activity of EEP was evaluated against gram-positive (S. aureus, methicillin-resistant S. aureus, E. faecalis) and gram-negative (E. coli and K. pneumoniae) bacteria by the minimal inhibitory concentration (MIC) test using the microdilution method. Furthermore, the growth curve and integrity of cell membrane of S. aureus and E. coli were investigated using standard microbiological methods. HPLC-DAD analysis showed that the EEP of M. quadrifasciata quadrifasciata has a more complex chemical composition than the EEP of T. angustula. Moreover, UPLC-MS analyses of M. quadrifasciata quadrifascita indicated flavonoids and terpenes as major constituents. The bactericidal activity of both EEPs was higher against gram-positive bacteria than for gram-negative bacteria. The EEP from M. quadrifasciata quadrifasciata presented MIC values lower than the EEP from T. angustula for all tested bacteria. The EEP from M. quadrifasciata quadrifasciata caused lysis of the bacterial wall and release of intracellular components from both E. coli and S. aureus. Our findings indicate that the chemical composition of propolis from stingless bees is complex and depends on the species. The extract from M. quadrifasciata quadrifascita was more effective against gram-positive than gram-negative strains, especially against S. aureus and methicillin-resistant S. aureus compared to T. angustula extract, by a mechanism that involves disturbance of the bacterial cell membrane integrity.

Objetivou-se neste estudo avaliar a sorção do oxadiazon em diferentes solos do Cerrado Brasileiro, destacando as correlações da dose letal do herbicida capaz de inibir 50% do acúmulo da massa seca do bioindicador (DL50) entre as características químicas do solo e seus efeitos diretos e indiretos. O experimento foi realizado em casa de vegetação, com delineamento em blocos casualizados com quatro repetições. Cada unidade experimental foi constituída de um vaso com doses crescentes do oxadiazon; utilizou-se a aveia (Avena sativa) como espécie bioindicadora. Na avaliação da sorção, foram utilizados areia lavada e 22 solos (substratos) provenientes de áreas cultivadas com Alliaceae no cerrado Brasileiro. Foram determinadas a DL50 e a relação de sorção (RS) = [(DL50solo - DL50areia)/DL50areia], para os substratos. Posteriormente, análise de correlação de Pearson foi realizada entre as características químicas dos substratos e a DL50 do oxadiazon. Foi quantificada ainda a análise de trilha, a fim de desdobrar somente as correlações significativas estimadas em efeitos diretos e indiretos de caracteres sobre a DL50, que é uma variável básica. A DL50 mais expressiva (528,09 g ha-1) para uma das amostras de solo de cerrado resultou em maior RS (> 53,00). Já no substrato de areia lavada, a DL50 foi de apenas 9,74 g ha-1 do oxadiazon (disponível no solo). Conclui-se que a sorção do oxadiazon é influenciada pelas características químicas dos solos, ressaltando a correlação com o pH (CaCl2), teor de magnésio, alumínio, matéria orgânica, carbono orgânico e a saturação por alumínio.

The objective of this study was to evaluate oxadiazon sorption in different soils of the Brazilian Cerrado, highlighting the correlations of lethal doses of this herbicide capable of inhibiting 50% of the dry matter accumulation of the bio-indicator (LD50) among the chemical characteristics of the soil and its direct and indirect effects. The experiment was carried out in a greenhouse in a randomized block design and four repetitions. Each experimental unit consisted of a pot with increasing rates of oxadiazon and oat (Avena sativa), as the bio-indicator species. For sorption evaluation, washed sand and 22 soils (substrates) from Cerrado Brazilian's Alliaceae cultivated areas were used. LD50 and sorption ratio (SR) = [(LD50soil - LD50sand)/LD50sand] to the substrates were determined. Pearson correlation analysis was performed between the chemical characteristics of the substrates and the LD50 of oxadiazon. A path analysis was quantified, to deploy only the significant correlations estimated in direct and indirect effects of the characters on LD50, which is a basic variable. A more pronounced LD50 (528.09 g ha-1) for the Cerrado soil sample resulted in higher SR (> 53.00), while in the washed sand substrate, LD50 corresponded only to 9.74 g ha-1 of the oxadiazon (available in soil). It was concluded that oxadiazon sorption is influenced by the chemical characteristics of the soils, highlighting the correlation with pH (CaCl2), magnesium content, aluminum, organic matter, organic carbon, and aluminum saturation.

The rat models currently employed for studies of nerve regeneration present distinct disadvantages. We propose a new technique of stretch-induced nerve injury, used here to evaluate the influence of gabapentin (GBP) on nerve regeneration. Male Wistar rats (300 g; n=36) underwent surgery and exposure of the median nerve in the right forelimbs, either with or without nerve injury. The technique was performed using distal and proximal clamps separated by a distance of 2 cm and a sliding distance of 3 mm. The nerve was compressed and stretched for 5 s until the bands of Fontana disappeared. The animals were evaluated in relation to functional, biochemical and histological parameters. Stretching of the median nerve led to complete loss of motor function up to 12 days after the lesion (P<0.001), compared to non-injured nerves, as assessed in the grasping test. Grasping force in the nerve-injured animals did not return to control values up to 30 days after surgery (P<0.05). Nerve injury also caused an increase in the time of sensory recovery, as well as in the electrical and mechanical stimulation tests. Treatment of the animals with GBP promoted an improvement in the morphometric analysis of median nerve cross-sections compared with the operated vehicle group, as observed in the area of myelinated fibers or connective tissue (P<0.001), in the density of myelinated fibers/mm2 (P<0.05) and in the degeneration fragments (P<0.01). Stretch-induced nerve injury seems to be a simple and relevant model for evaluating nerve regeneration.

Solallum acanthodes. popularmente conhecido como "jurubeba", foi estudada com o objetivo de avaliar suas propriedades antinocicept i vas nos modelos de nociccpção induzida pela I'ormalina e glutamato. Para isto foi utilizado o extrato elanólico dos frutos (EES) da planta. Os resultados apresentaram altos níveis de significância, demonstrando o potencial analgésico de S. acanthodes.

Solanum acanthodes, popularly known as "jurubcba", was studied with the objective to evaluatc its antinocíccptivc propcrties In lhe models aI' fonnalin-induced nociceptive and glutamate. For this lhe cthanolic extract of lhe fruits (E.ES) of the plant was used. The results had prescnlcd high lcvcls 01' significance, demonstrating lhe analgesic potcntial of S. acanthodes.