cytellin and Hyperglycemia

Hyperglycemia is a major public health problem worldwide and there is increasing demand for prevention of postprandial hyperglycemia in diabetic, prediabetic, and healthy humans.. We investigated whether rice bran and triterpene alcohol and sterol preparation (TASP) lowered hyperglycemia in mice and humans. Brown rice and white rice supplemented with TASP lowered the postprandial hyperglycemia in humans. TASP and its components (cycloartenol [CA], 24-methylene cycloartanol, β-sitosterol, and campesterol) decreased postprandial hyperglycemia in C57BL/6J mice. Glucose transport into everted rat intestinal sacs and human HuTu80 cells transfected with sodium-glucose cotransporter-1 (SGLT1) was significantly reduced by the addition of CA. Intracellular localization analysis suggested that SGLT1 translocation to the apical plasma membrane was inhibited when the cells were treated with CA.. We demonstrated for the first time that TASP from rice bran lowered postprandial hyperglycemia in mice and humans. The smaller increase in blood glucose following TASP consumption may be due to the CA-induced decrease in glucose absorption from the intestine, which may be related to decreased membrane translocation of SGLT1.

Topics: Adult; Animals; Blood Glucose; Body Mass Index; Body Weight; Cell Line, Tumor; Cholesterol; Dietary Fiber; Humans; Hyperglycemia; Insulin; Male; Mice; Mice, Inbred C57BL; Oryza; Phytosterols; Rats; Rats, Wistar; Single-Blind Method; Sitosterols; Sodium-Glucose Transporter 1; Sterols; Triterpenes

Banana is an extensively cultivated plant worldwide, mainly for its fruit, while its ancillary product, the banana pseudostem, is consumed as a vegetable and is highly recommended for diabetics in the traditional Indian medicine system. The present study was aimed at elucidating the mechanism of antihyperglycaemia exerted by the ethanol extract of banana pseudostem (EE) and its isolated compounds viz., stigmasterol (C1) and β-sitosterol (C2), in an alloxan-induced diabetic rat model. Diabetic rats which were administered with C1, C2 and EE (100 and 200 mg per kg b. wt.) for 4 weeks showed reduced levels of fasting blood glucose and reversal of abnormalities in serum/urine protein, urea and creatinine in diabetic rats compared to the diabetic control group of rats. Diabetic symptoms such as polyphagia, polydipsia, polyuria, urine glucose and reduced body weight were ameliorated in the diabetic group of rats fed with EE, C1 and C2 (100 mg per kg b. wt., once daily) for 28 days. The levels of insulin and Hb were also increased, while the HbA1c level was reduced. The altered activities of hepatic marker enzymes viz., aspartate transaminase (AST), alanine transaminase (ALT) and alkaline phosphatase (ALP); glycolytic enzyme (hexokinase); shunt enzyme (glucose-6-phosphate dehydrogenase); gluconeogenic enzymes (glucose-6-phosphatase, fructose-1,6-bisphosphatase and lactate dehydrogenase) and pyruvate kinase were significantly reverted to normal levels by the administration of EE, C1 and C2. In addition, increased levels of hepatic glycogen and glycogen synthase and the corresponding decrease of glycogen phosphorylase activity in diabetic rats illustrated the antihyperglycaemic potential of EE and its components. The histological observations revealed a marked regeneration of the β-cells in the drug treated diabetic rats. These findings suggest that EE might exert its antidiabetic potential in the presence of C1 and C2, attributable to the enhanced glycolytic activity, besides increasing the hepatic glucose utilization in diabetic rats by stimulating insulin secretion from the remnant β-cells.

Topics: Alloxan; Animals; Biomarkers; Cell Line, Tumor; Diabetes Mellitus, Experimental; Dietary Supplements; Ethnopharmacology; Female; Hyperglycemia; Hypoglycemic Agents; Insulin; Insulin Secretion; Insulin-Secreting Cells; Male; Medicine, Ayurvedic; Musa; Plant Extracts; Plant Leaves; Rats; Rats, Wistar; Sitosterols; Stigmasterol; Toxicity Tests, Acute

Oxidative stress, produced under diabetic conditions, may cause tissue damage. Although several drugs are currently available for the treatment of diabetes, their continued use may cause unwanted side effects. The aim of the present study was to evaluate the antioxidant potential of β-sitosterol (BS), a phytosterol from Solanum surattense, using an experimental model for diabetes-induced oxidative damage.. The effects of 21 days treatment with BS (10, 15 and 20 mg/kg, p.o.) on blood, serum, and tissue biochemical parameters were evaluated in control and streptozotocin-induced diabetic rats. Nine experimental groups, including a control group, a diabetic group, and BS- and glibenclamide-treated diabetic groups, were evaluated.. All three dose levels dose dependently resulted in decreases in glycated hemoglobin, serum glucose, and nitric oxide, with concomitant increases in serum insulin levels. Furthermore, treatment with BS doses also increased pancreatic antioxidant levels, with a concomitant decrease in thiobarbituric acid-reactive substances.. β-Sitosterol has promising antidiabetic as well as antioxidant effects and may be considered in clinical studies for drug development.

Topics: Animals; Antioxidants; Blood Glucose; Catalase; Diabetes Mellitus, Experimental; Dose-Response Relationship, Drug; Female; Glutathione; Glyburide; Glycated Hemoglobin; Glycosuria; Hyperglycemia; Hypoglycemic Agents; Insulin; Islets of Langerhans; Male; Molecular Structure; Nitric Oxide; Rats; Rats, Wistar; Sitosterols; Solanum; Streptozocin; Superoxide Dismutase; Treatment Outcome