Biological activities of Yacon leaves in diabetic animals

Puerto Madryn

Congreso; XLVI REUNION ANUAL- SOCIEDAD ARGENTINA DE INVESTIGACION EN BIOQUIMICA Y BIOLOGIA MOLECULAR.; 2010

BIOLOGICAL ACTIVITIES OF YACON LEAVES IN DIABETIC ANIMALS Serra Barcellona C, Cabrera WM, Genta SB, Sánchez SS. INSIBIO (CONICET-UNT). Chacabuco 461. T4000ILI – SM de Tucumán, Argentina. E-mail: cserrabarcellona@fbqf.unt.edu.ar   Medicinal plants have long been an excellent source of pharmaceutical agents. Accordingly, the objectives of many investigations are to discover and isolate new therapeutic agents based on plant-derived compounds. Smallanthus sonchifolius (yacon) is an Andean crop used for centuries by prehispanic population in traditional medicine. We demonstrated that a 10% yacón leaves decoction (140mg dry extract/kg bw) produced a fast and significant decrease in plasma glucose levels of diabetic rats. The bioactivity screening of organic extracts of yacón leaves revealed that butanol and ethyl acetate are the most effective fractions to reduce postprandial glucose levels. Phytochemical analysis of butanol extract showed the presence of caffeic, chlorogenic and dicaffeoilquinic. Enhydrin was the major sesquiterpene lactone in the ethyl acetate fraction and had significant hypoglycemic action at dose of 0,8mg dry extract/kg bw. In order to clarify the mechanism of hypogycemic action of enhydrin and yacón decoction we tested the inhibitory activity on α-glucosidase in vitro and in vivo. The results showed that both samples suppressed the carbohydrate absorption from intestine reducing the postprandial increase of blood glucose. Toxicity study of yacon decoction and enhydrina using normal Wistar rats demonstrated that yacon decoction and enhydrin, are safe in the therapeutic dosage range.