ABSTRACT
Propolis has been used worldwide for years in folk medicine and currently marketed by the pharmaceutical industry. In Brazil, propolis was classified into 13 groups based on their organoleptics and physicochemical characteristics. The 13th type named red propolis has been an important source of investigation since late 90s. Their property comes from the countless compounds, including terpenes, pterocarpans, prenylated benzophenones and especially the flavonoids. This last compound class has been indicated as the responsible for its potent pharmacological actions, highlighting the antimicrobial, anti-inflammatory, antioxidant, healing and antiproliferative activities. The red propolis can also be found in other countries, especially Cuba, which has similar features as the Brazilian. Therefore, with the compilation of 80 papers, this review aims to provide a key reference for researchers interested in natural products and discovery of new active compounds, such as from propolis.
ABSTRACT
Objective To investigate the antidiabetic effect of Rourea cuspidata hydroalcoholic stem extract in normal and streptozotocin-induced diabetic rats. Methods In order to evaluate the chemical composition, different extracts from stem in ascending solvent order of polarity were prepared. The extracts were analyzed by high resolution mass spectrometry and 7 compounds were identified, including hyperin, an important and already reported active compound in the literature. Hyperin was also quantified by HPLC-UV in all the extracts. The hydroalcoholic stem extract (Ss5), which showed the highest concentration of hyperin, was administered to STZ-induced diabetes rats to evaluate the potential hypoglycemic activity. Total cholesterol, HDL, triglycerides, ALT and AST were also evaluated. In the present study, the effects of oral administration of hydroalcoholic stem extract (200 mg/kg b. wt.) for 28 days on the level of serum glucose, total cholesterol, HDL, triglycerides, aspartate amino transferase (AST) and alanine amino transferase (ALT) in normal and streptozotocin-induced diabetic rats were evaluated. Histopathological changes in diabetic rats' pancreas were also studied. Results The extract exposition demonstrated hypoglycemic effect like the drug control glibenclamide. The extract was able to increase the HDL levels. Histopathological study on diabetic rats' pancreas after extract treatment showed morphological alterations in STZ-induced diabetes rats, which were apparently restored after extract treatment. Conclusions This work demonstrates the potential use of R. cuspidata as hypoglycemic agent in the treatment of diabetes.