RESUMO
Diabetes mellitus is a heterogeneous metabolic disorder characterized by hyperglycaemia resulting in defective insulin secretion, resistance to insulin action or both. The use of biguanides, sulphonylurea and other drugs are valuable in the treatment of diabetes mellitus; their use, however, is restricted by their limited action, pharmacokinetic properties, secondary failure rates and side effects. Trigonella foenum-graecum, commonly known as fenugreek, is a plant that has been extensively used as a source of antidiabetic compounds from its seeds and leaf extracts. Preliminary human trials and animal experiments suggest possible hypoglycaemic and antihyperlipedemic properties of fenugreek seed powder taken orally. Our results show that the action of fenugreek in lowering blood glucose levels is almost comparable to the effect of insulin. Combination with trace metal showed that vanadium had additive effects and manganese had additive effects with insulin on in vitro system in control and diabetic animals of young and old ages using adipose tissue. The Trigonella and vanadium effects were studied in a number of tissues including liver, kidney, brain peripheral nerve, heart, red blood cells and skeletal muscle. Addition of Trigonella to vanadium significantly removed the toxicity of vanadium when used to reduce blood glucose levels. Administration of the various combinations of the antidiabetic compounds to diabetic animals was found to reverse most of the diabetic effects studied at physiological, biochemical, histochemical and molecular levels. Results of the key enzymes of metabolic pathways have been summarized together with glucose transporter, Glut-4 and insulin levels. Our findings illustrate and elucidate the antidiabetic/insulin mimetic effects of Trigonella, manganese and vanadium.
RESUMO
AIM To observe the effect of sodium orthovanadate on glucose and maltose absorption and to reveal its mechanism. METHODS ① Normal Wistar rats were divided into 6 groups at random, 0 9% NaCl group, acarbose group(30 mg?kg -1 ) and sodium orthovanadate high dose(16 mg?kg -1 ), middle dose (4 mg?kg -1 ) and low dose (1 mg?kg -1 )groups. The values of blood glucose of all the groups were measured with oxidation enzyme method after administration of glucose and maltose. ② The ? glucosidase was abstracted from the upper small intestine and the inhibitory effect of sodium orthovanadate on ? glucosidase was examined. RESULTS ① Sodium orthovanadate could delay the peak values of plasma glucose induced by glucose, with AUC in these groups lower than that in controls, that is (8 42?0 63) mmol?h -1 ?L -1 ( P
RESUMO
AIM To observe the anti hyperglycemic effect of sodium orthovanadate on type 2 diabetes rats. METHODS Rats were fed by highly fatted food to grow into obesity. Then values of plasma free fatty acid (FFA) were tested. Glucose disposal was measured with the hyperinsulinemic euglycemic clamp technique to assess insulin resistance in vivo. Small dose of streptozocin was injected ip with insulin resistance. Those with plasma glucose over 11 1 mmol?L -1 were assigned to type 2 diabetes model group, continually fed with sodium orthovanadate for 3 days and assayed the values of plasma glucose in fasting state. RESULTS ①Rats fed with fatted food needed more insulin to maintain normal plasma glucose, ie (0 54?0 02) U?min -1 , higher than that of normal control ( P
RESUMO
AIM To study toxicity and mechanism of SOV on ventricular myocardial cells. METHODS Cyclical perfusion was used to acutely detach the mature guinea pig myocytes into single cells. The CK,LDH activity in a medium of myocardial cells was measured for 30,60,120 and 180 min after the effect of SOV at 1,10, 100 ?mol?L -1 and 1 mmol?L -1 . Rates of cell viability and apoptosis were also measured. The protein content and Na +,K + ATP enzyme activity of the myocardial cells were measured as well. An electron microscope was used to investigate cell nucleus and organelle morphology. RESULTS The release of CK, LDH and protein from the myocardial cell gradually increased after administering SOV at 100 ?mol?L -1 and 1 mmol?L -1 to the cells. While ,the cell activity decreased. CK release, which indicated the extent of myocardial cell injury, was more sensitively than that of LDH and cell viability. Meanwhile ,the activity of Na +,K + ATP enzyme decreased gradually. The rate of apoptosis of myocardial cells significantly changed for 180 min after treated with SOV at 100 ?mol?L -1 and 1 mmol?L -1 . CONCLUSION Guinea pig ventricular myocardial cells were only injured when exposed for 30 min to 100 ?mol?L -1 and 1 mmol?L -1 concentrations of SOV higher than the effective concentration of the drug.
RESUMO
Sodium orthovanadate is one of vanadate salts. When administered orally to STZ-induced diabetic rats, sodium orthovanadate may stimulate glucose uptake and. metabolism and made them normoglycemic. However, the blood glucose levels of normal rats treated with sodium orthovanadate did not change despite their plasma insulin levels decreased. The insulin-like effect of sodium orthovanadate on carbohydrate metabclism was not due to direct stimulation of insulin secretion, because the plasma insulin concentration of vanadate-treated STZ-rats remained lower and insulin secretion of isolated pancreas perfused with solution containing sodium orthovanadate was smilar to that of controls.