Silmara Baroni

Effect of crude extracts of leaves of Smallanthus sonchifolius (yacon) on glycemia in diabetic rats

The present study investigated the effect of crude extracts from yacon leaves, obtained by aqueous cold (YC) or hot (YH) extraction, or hydro-ethanolic extraction (YE), on glycemia of the diabetic (induced by streptozotocine, 50 mg/kg, ip) and nondiabetic rats. The animals were treated orally with the extracts (400 mg/kg) or water for 3, 7, 10, and 14 days. After this period, the animals were anesthetized and blood samples were collected for measurement of plasmatic glucose and creatinine and activity of the enzymes (AST, ALT, ALP). Also were evaluated the consumption of food, water, urine volume, body weight of the animals and LD50 of YE. Treatment with YE for 14 days reduced glycemia in diabetic and nondiabetic animals. No similar reduction was observed in animals treated with YC or YH. Additionally, YE restored the activity of the plasmatic enzymes that were altered, and improved weight gain in the diabetic animals. These results showed that the effectiveness of the yacon extracts is related to the method of preparation and to the time of treatment. The effect of YE on glycemia in diabetic rats is not related to reduction of food intake or to interference of the extract with intestinal absorption of carbohydrates.

Effect of Stryphnodendron adstringens (barbatimão) bark on animal models of nociception

A atividade antinociceptiva do extrato bruto e fracoes do Stryphnodendron adstringens (Mart.) Coville (barbatimao) foi avaliada. Foram usados tres modelos experimentais para avaliacao da dor: teste de contorcao abdominal induzida pelo acido acetico, teste da formalina e teste da placa quente. Os resultados mostraram um efeito antinociceptivo evidente do barbatimao nos modelos experimentais de contorcao induzida por acido acetico e dor induzida pela formalina. Por outro lado, o barbatimao nao modificou significativamente o tempo de latencia dos animais no teste da placa quente. Estes resultados sugerem que o extrato de barbatimao apresenta efeito antinociceptivo por mecanismos perifericos.

Avaliação das propriedades de intumescimento e permeabilidade de filmes isolados de polimetacrilato contendo polissacarídeo da raiz de Lótus (Nelumbo nucifera)

Polysaccharides such as extracted from Lotus root (Nelumbo nucifera) combined with polymethacrylates on isolated films for film coating was studied as potential vehicles for colonic drug delivery, susceptible to fermentation by micro flora. For the preparation we used the association of Eudragit®RS 30D and polysaccharides in different concentrations (100:0, 90:10, 80:20, 70:30) in aqueous-based solvents. In the present study, the films were characterized by swelling studies and water vapor transmission studies. These tests demonstrated that different associations do not present significant differences, showing that the physico-chemical properties of EudragitâRS 30D are not altered and this material will be able to be applied for film formation in coating for colonic drug delivery system development.

Inhibitory Effect of Helicteres gardneriana Ethanol Extract on Acute Inflammation

The anti-inflammatory effect of an ethanol extract of Helicteres gardneriana (Nees) Castiglioni was assayed in experimental models of pleurisy and microcirculation in situ. Treatment of animals with 500 mg/kg body weight reduced the exudate volume (35% reduction) induced by intrapleural injection of carrageenan and the migration of polymorphonuclear cells into the inflamed pleural cavity of rats (40%). Additionally, rolling and adhesion of leukocytes and the number of leukocytes that migrated toward the perivascular space in response to the carrageenan injection were decreased by the extract (500 mg/kg). These data demonstrate the anti-inflammatory effect of the ethanol extract of Helicteres gardneriana and imply that inhibition of leukocyte-endothelial interactions is important in the extracts mechanism of action.