Isolated Compounds from Natural Products with Potential Antidiabetic Activity - A Systematic Review.

BACKGROUND: Worldwide, Type 2 diabetes has become a growing health problem. While many research articles in the field of ethnopharmacology have focused on the antidiabetic properties of medicinal plant species, insufficient evidence remains regarding their therapeutic use. Studies using both in vitro and in vivo models are necessary to evaluate various medicinal plants species, used in folk medicine, by using scientific criteria. METHODS: This review focuses on isolated compounds from medicinal plant species that have reported antidiabetic activity in diabetes models. Searches using MEDLINE/PUBMED and SCOPUS databases were conducted to find articles in English on compounds isolated from plant species that have been tested using in vivo and/or in vitro diabetes models and published between 01/01/2005 and 12/31/2015. RESULTS: The majority of studies involved in vitro assays that used the analysis of enzymes and receptors to investigate the antidiabetic mechanisms of active compounds at the molecular level. Compounds that have been reported to have important anti-diabetic activity with defined mechanisms were identified, including quercetin, oleanolic acid, kaempferol, ursolic acid, rutin, ß-sitosterol, and mangiferin. CONCLUSION: This review contributes to the field of ethnopharmacology and should impact the design of new strategies in the search of novel compounds for the treatment of diabetic conditions.

Chemical and pharmacological investigation of the stem bark of Synadenium grantii.

Based on the fact that Synadenium grantii is used in folk medicine for the treatment of peptic ulcers and inflammatory diseases, this work describes its chemical and pharmacological properties. Pharmacological investigation of the crude bark extract showed a high antioxidant activity over several scavenger systems, such as 2,2'-azino-bis (3-ethylenebenzothiazoline-6-sulfonic acid)• +, 1-diphenyl-2-picrylhydrazyl•, O2 • - , and HOCl, as well as an enzymatic system with human myeloperoxidase and an ex vivo hemolysis system. Furthermore, the oral administration of the crude bark extract was able to reduce carrageenan-induced rat paw edema as effectively as ibuprofen. These biological activities may be associated with the presence of flavonoids and terpenes, as revealed by HPLC and NMR analyses of the crude stem bark extract. The phytochemical investigations in this study resulted in the isolation of friedelin and 3ß-friedelinol for the first time, while euphol and lanosterol were also isolated.