Phytomodulatory proteins promote inhibition of hepatic glucose production and favor glycemic control via the AMPK pathway.

Phytomodulatory proteins from the latex of the medicinal plant Calotropis procera has been shown to be implicated in many pharmacological properties. However there is no current information about their activity on glucose metabolism, although the latex is used in folk medicine for treating diabetes. In this study the phytomodulatory proteins (LP) from C. procera latex were assessed on glycemic homeostasis. Control animals received a single intravenous dose (5 mg/kg) of LP or saline solution (CTL). Four hours after treatment, the animals were euthanized and their livers were excised for analysis by western blot and RT-PCR AMP-activated protein kinase (AMPK), phosphoenolpyruvate carboxykinase (PEPCK) and tumor necrosis factor alpha (TNF-α). In vivo tests of intraperitoneal tolerance to insulin, glucose and pyruvate were also performed, and the effect of LP administration on fed glycemia was studied followed by blood analysis to determine serum insulin levels. Treatment with LP reduced glycemia two hours after glucose administration (LP: 87.2 ± 3.70 mg/dL versus CTL: 115.6 ± 8.73 mg/dL). However, there was no change in insulin secretion (CTL: 14.16 ± 0.68 mUI/mL and LP: 14.96 ± 0.55 mUI/mL). LP improved the insulin sensitivity, represented by a superior glucose decay constant during an insulin tolerance test (kITT) (4.17 ± 0.94%/min) compared to the CTL group (0.82 ± 0.72%/min), and also improved glucose tolerance at 30 min (105.2 ± 12.4 mg/dL versus 154.2 ± 18.51 mg/dL), while it decreased hepatic glucose production at 15 and 30 min (LP: 75.5 ± 9.31 and 52.5 ± 12.05 mg/dL compared to the CTL: 79.0 ± 3.02 and 84.5 ± 7.49 mg/dL). Furthermore, there was a significant inhibition of gene expression of PEPCK (LP: 0.66 ± 0.06 UA and CTL: 1.14 ± 0.22 UA) and an increase of phosphorylated AMPK (LP: 1.342 ± 0.21 UA versus CTL: 0.402 ± 0.09 UA). These findings confirm the effect of LP on glycemic control and suggest LP may be useful in diabetes treatment. However, the pharmacological mechanism of LP in PEPCK modulation still needs more clarification.

Serum and liver lipids distributions in streptozotocin induced diabetic rat treated with diet containing Yam (Dioscorea bulbifera) flour / Suero y hepáticas lípidos en ratas diabéticas tratados con dieta que contenía harina ñame (Dioscorea bulbifera)

Introduction: Liver disease as a major cause of mortality in patients with diabetes mellitus. There is a interest to investigate the hypolipidemic properties of yam. The goal was assess the role of Brazilian yam (Dioscorea bulbifera) on serum and hepatic levels of triglycerides and cholesterol, in female diabetic rats. Methods: The rats were divided into three groups: Control (C), Diabetic (DM); Diabetic Yam (DMY), treated with diet containing 25g/100g of yam flour. After 5 weeks of experiment, glucose, insulin, gonadal fat and liver mass were evaluated. Serum and liver concentrations of triglycerides and cholesterol concentrations were quantified. Total liver thiols were determined. Results: After the 5 weeks, experimental groups shower (P < 0.05): Lower body mass; lower serum insulin; higher food intake and higher blood glucose concentration. DMY (vs. DM) group showed (P < 0.05): Lower blood glucose; higher gonadal fat mass; lower serum and hepatic triglycerides; higher hepatic cholesterol and thiols concentrations. DMY (vs. C) group showed: Similar serum and hepatic triglycerides and hepatic thiols. Conclusions: Brazilian yam (Dioscorea bulbifera) alleviated the consequences of the experimental diabetic disease, suggesting protection to hypertriglyceridemia and lipid peroxidation (AU)

Introducción: La enfermedad hepática como una de las principales causas de mortalidad en los pacientes con diabetes mellitus. Hay un interés para investigar las propiedades hipolipemiantes de ñame. El objetivo era evaluar el papel de ñame brasileña (Dioscorea bulbifera) en suero y los niveles hepáticos de triglicéridos y colesterol, en las ratas diabéticas . Métodos: Las ratas se dividieron en tres grupos: control (C), diabéticos (DM); Diabetic ñame (DMA), se trata con dieta que contenía 25 g / 100 g de harina de ñame. Después de 5 semanas de experimento, la glucosa, la insulina, la grasa gonadal y la masa del hígado fueron evaluados. Se cuantificaron las concentraciones de suero e hígado de los triglicéridos y las concentraciones de colesterol. Se determinaron los tioles totales de hígado. Resultados: Después de las 5 semanas, experimental ducha grupos (p < 0.05) : la masa corporal inferior; insulina sérica inferior; más alta la ingesta de alimentos y una mayor concentración de glucosa en sangre. DMY (vs. DM) grupo mostró (P < 0.05) : Baje la glucosa en sangre; masa grasa gonadal superior; inferior y triglicéridos séricos hepáticas; más altos de colesterol y tioles concentraciones hepáticas. DMY (vs. C) grupo mostró: suero similares y triglicéridos hepáticos y tioles hepáticas. Conclusiones: Ñame brasileño (Dioscorea bulbifera) alivian las consecuencias de la enfermedad diabética experimental, lo que sugiere protección para la hipertrigliceridemia y la peroxidación lipídica (AU)