In vitro hypoglycemic activity of Ziziphus Jujuba

Abstract

Recent reports have indicated that continuous treatment withnutritional jujuba (Ziziphus jujuba Miller) fruit extracts in dia-betic rats improved glucose utilization and produced a significantdecrease in the blood glucose. In the present study, hypoglycemicactivity ofZ. jujubawas investigated using various in vitro tech-niques.The hypoglycemic effect ofZ. jujubain phosphate bufferedsaline which grown in Balıkesir was studied by measuring glucoseadsorption, glucose diffusion and glucose uptake by yeast cells.The glucose content in the solution measured by spectrophoto-metrically with commercially kits.The adsorption capacity of theZ. jujubawas found to bedirectly proportional to the molar concentration of glucose. Theglucose binding capacity of extract increased in higher glucoseconcentratrations. There was significant differences were observedbetween the adsorption capacities ofZ. jujubaand control sam-ples (p<0.05). The rate of glucose diffusion was directly propor-tional to the time. Diffusion rate was significantly lower in thesolution containingZ. jujubacompared to control (p<0.05).The extract demonstrated significant inhibitory effects on move-ment of glucose into external solution across dialysis membranecompared to control. The rate of glucose transport across cellmembrane in yeast cells was observed to be inversely propor-tional to the molar glucose concentration.Z. jujubainhibited glu-cose transport across the yeast cells.The results showed thatZ. jujubareduced glucose levels atleast by three mechanisms. First by increasing glucose adsorptioncapacity during postprandial hyperglycemia; second by retardingglucose diffusion rate and third, at the cellular level by inhibitingglucose transport across the cell membrane. All of thesedecreased the absorption of glucose in the intestinal cells and theconcentration of postprandial serum glucose.