Syzygium cumini (L.) Skeels (Myrtaceae) has been traditionally used to treat a number of illnesses. Ethnopharmacological studies have particularly addressed antidiabetic and metabolic-related effects of extracts prepared from its different parts, especially seed and pulp-fruit, however there is a lack of studies on phytochemical profile and biological properties of its leaf. As there is considerable interest in bioactive compounds to treat metabolic syndrome and its clustered risk factors, we sought to characterize the metabolic effects of hydroethanolic extract of S. cumini leaf (HESc) on lean and monosodium L-glutamate (MSG)-induced obese rats. HPLC-MS/MS characterization of the HESc polyphenolic profile, at 254 nm, identified 15 compounds pertaining to hydrolysable tannin and flavanol subclasses. At 60 days of age, both groups were randomly assigned to receive HESc (500 mg/kg) or vehicle for 30 days. At the end of treatment, obese+HESc exhibited significantly lower body weight gain, body mass index, and white adipose tissue mass, compared to obese rats receiving vehicle. Obese rats treated with HESc showed a 2-fold increase in lipolytic activity in the periepididymal fat pad, as well as, brought triglyceride levels in serum, liver and skeletal muscle back to levels close those found in lean animals. Furthermore, HESc also improved hyperinsulinemia and insulin resistance in obese+HESc rats, which resulted in partial reversal of glucose intolerance, as compared to obese rats. HESc had no effect in lean rats. Assessment of ex vivo glucose-stimulated insulin secretion showed HESc potentiated pancreatic function in islets isolated from both lean and obese rats treated with HESc. In addition, HESc (10 – 1000 ug/mL) increased glucose stimulated insulin secretion from both isolated rat islets and INS-1E beta cells. These data demonstrate that S. cumini leaf improved peripheral insulin sensitivity via stimulating/modulating beta cell insulin release, which was associated with improvements in metabolic outcomes in MSG-induced obese rats.

Melipona fasciculata Smith é uma abelha nativa, social e sem ferrão que produz cera, mel e geoprópolis. O presente trabalho objetivou caracterizar, do ponto de vista farmacognóstico, o geoprópolis de Melipona fasciculata, coletado em meliponários nos municípios de Arari, São Bento e São João Batista, da Baixada maranhense, no Estado do Maranhão, visando estabelecer dados para o controle de qualidade e padronização do produto. A metodologia utilizada constou de análises sensoriais, abordagem química, perfis cromatográficos e determinação dos teores de flavonóides. Os resultados demonstram que o geoprópolis apresenta características sensoriais similares às encontradas para própolis de Apis mellifera, presença de compostos fenólicos em maior concentração, além de substâncias da classe dos terpenos e saponinas e ausência de alcalóides. Os perfis cromatográficos indicaram que a composição e concentração das substâncias químicas são diferentes entre as amostras. Os teores de flavonóides variaram de 0,17 - 2,6%, os quais para a maioria das amostras apresentaram valores acima do mínimo exigido pela legislação brasileira para própolis de Apis mellifera. Os dados encontrados sugerem que as variações qualitativa e quantitativa de flavonóides e outros constituintes químicos no geoprópolis são fortemente afetados pela flora visitada pelas abelhas, região geográfica e fatores ambientais. Melipona fasciculata Smith is a native, social, stingless bee species that produces wax, honey and geopropolis. This work aimed to do a pharmacological evaluation of Melipona fasciculata geopropolis, collected in beehives in the municipal districts of Arari, São Bento and São João Batista, in Baixada maranhense, in the state of Maranhão, Brazil, seeking to obtain basis for the quality control and standardization of the product. The methodology used included the accomplishment of sensorial analyses, chemical approach, chromatographic profiles and determination of the flavonoids contents. The results demonstrate that the geopropolis have organoleptic characteristics similar to the ones found for the propolis of Apis mellifera, presence of phenolic compounds in larger concentration, besides substances of the class of the terpenes and saponins and absence of alkaloids. The chromatographic profiles indicated that the composition and concentration of the chemical substances are different among the samples. The flavonoids contents ranged between 0.17 - 2.6%. The content for most of the samples presented values above the minimum demanded by the Brazilian legislation for propolis of Apis mellifera. The found data suggest that the qualitative and quantitative variations of flavonoids and other chemical substances in geopropolis are strongly affected for the flora visited by the bees, geographical area and environmental factors

Geopropolis, a mixture of plant resin, wax, soil and salivary secretion, is produced by the stingless bee Melipona fasciculata. This aim of this study was to investigate the chemical composition and antioxidant activity of geopropolis collected from beehives in two phytogeographical regions, flooded fields and cerrado, in the municipalities of Palmeirândia and Fernando Falcão, Maranhão State, northeastern Brazil. The geopropolis compounds were identified by gas chromatography-mass spectrometry (GC/MS). Additionally, total phenolic content was determined with the Folin−Ciocalteu reagent and antioxidant activity was evaluated in vitro by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. The four geopropolis samples varied in terms of total phenolic content and antioxidant activity and the highest values were observed for geopropolis from Fernando Falcão. Triterpenes such as cycloartane, ursane and oleanane and phenolic acids (protocatechuic acid and gallic acid) were identified in the geopropolis from Palmeirândia, while the phenolic acids, gallic and ellagic acid were the main compounds in geopropolis from Fernando Falcão. The antioxidant property of geopropolis is due to its high total phenolic content and predominance of gallic acid and ellagic acid. The results showed that the plant resources in two phytogeographical regions of Maranhão used by bees for the production of geopropolis contribute to the chemical composition and bioactivity of this product.