RESUMEN
We examined the effects of an arabinogalactanprotein (WSSP-AGP) from Ipomoea batatas L. on hyperglycemia in db/db mice. An oral glucose tolerance test indicated significantly decreased plasma glucose levels by WSSP-AGP. Additionally, an insulin tolerance test found improvement in insulin sensitivity due to treatment with WSSP-AGP. This suggests that amelioration of insulin resistance by WSSP-AGP causes to lead its hypoglycemic effects.
Asunto(s)
Glucemia/efectos de los fármacos , Diabetes Mellitus/sangre , Hipoglucemiantes/administración & dosificación , Mucoproteínas/administración & dosificación , Animales , Glucemia/análisis , Diabetes Mellitus/tratamiento farmacológico , Diabetes Mellitus/fisiopatología , Modelos Animales de Enfermedad , Femenino , Prueba de Tolerancia a la Glucosa , Hiperglucemia/sangre , Hipoglucemiantes/sangre , Hipoglucemiantes/química , Hipoglucemiantes/uso terapéutico , Insulina/sangre , Resistencia a la Insulina , Ipomoea batatas/química , Ratones , Ratones Transgénicos , Mucoproteínas/química , Mucoproteínas/uso terapéutico , Pioglitazona , Proteínas de Plantas/administración & dosificación , Proteínas de Plantas/química , Proteínas de Plantas/uso terapéutico , Tiazolidinedionas/administración & dosificación , Tiazolidinedionas/uso terapéuticoRESUMEN
An arabinogalactan-protein (WSSP-AGP) was isolated from the tuberous cortex of the white-skinned sweet potato (WSSP; Ipomoea batatas L.). It consists of 95% (w/w) carbohydrate and 5% (w/w) protein with high contents of hydroxyproline, alanine, and serine. Its sugar composition is α-L-Rha:α-L-Ara:ß-D-Gal:ß-D-GlcA in a molar ratio of 1.0:4.1:7.6:1.3. Its weight-average molecular weight was estimated to be 126,800 g/mol by high-performance size exclusion chromatography coupled with multiangle laser light scattering. Structural analysis indicated that WSSP-AGP is a (1â3)-ß-D-galactan highly branched at O-6 with (1â6)-ß-D-galactan, in which the branched chains are substituted at the O-3 position with α-L-Araf-(1â and α-L-Araf-(1â5)-α-L-Araf-(1â and at the O-6 position typically with α-L-Rhap-(1â4)-ß-D-GlcAp-(1â as terminating groups. Continuous administration of WSSP-AGP to KKAy mice significantly lowered fasting plasma glucose levels. This indicates that WSSP-AGP plays an important role in the hypoglycemic effects of WSSP.
Asunto(s)
Hipoglucemiantes/administración & dosificación , Hipoglucemiantes/química , Ipomoea batatas/química , Mucoproteínas/administración & dosificación , Mucoproteínas/química , Extractos Vegetales/administración & dosificación , Extractos Vegetales/química , Animales , Modelos Animales de Enfermedad , Humanos , Hipoglucemia/tratamiento farmacológico , Masculino , Ratones , Peso Molecular , Proteínas de Plantas/administración & dosificación , Proteínas de Plantas/química , Tubérculos de la Planta/química , Distribución AleatoriaRESUMEN
A novel 13-membered ring thiocyclitol, isolated from an aqueous extract of Kothala-himbutu (Salacia reticulata), inhibited alpha-glucosidase in vitro. The inhibitory activity was investigated by maltose- and sucrose-loading on Wistar rats. This study found significant lowering of postprandial glucose levels, and the potency of 13-membered ring thiocyclitol was confirmed in vivo.
Asunto(s)
Ciclitoles/farmacología , Inhibidores Enzimáticos/farmacología , Inhibidores de Glicósido Hidrolasas , Salacia/química , Animales , Glucemia/efectos de los fármacos , Ciclitoles/aislamiento & purificación , Inhibidores Enzimáticos/aislamiento & purificación , Hipoglucemiantes/aislamiento & purificación , Hipoglucemiantes/farmacología , Maltosa/sangre , Periodo Posprandial , Ratas , Ratas Wistar , Sacarosa/sangreRESUMEN
A polyhydroxylated cyclic 13-membered sulfoxide (1) was isolated from an aqueous extract of Kothala-himbutu ( Salacia reticulata WIGHT). The structure of compound 1 was elucidated by 1D and 2D NMR and APCI-MS methods. The alpha-glucosidase inhibitory activity of compound 1 (IC 50: maltase, 0.227 microM; sucrase, 0.186 microM; isomaltase, 0.099 microM) was much greater than the inhibitory activity of salacinol and kotalanol, which were previously isolated from Kothala-himbutu.