Antihperglycaemic and Antihyperlipidaemic Activities of Aqueous Ethanol Root Extract of Pseudocedrela Kotschyi on Alloxan-Induced Diabetic Rats.

Aim: To evaluate the antihyperglycaemic and antihyperlipidaemic properties of Pseudocedrela kotschyi in alloxan induced diabetic rats. Materials and Methods: Fasting blood glucose (FBG) was conducted by first inducing diabetes through intraperitoneal administration of alloxan monohydrate (150 mg/kg body weight) (bwt). The diabetic rats, 5 per group received graded extract doses (100, 250 and 500 mg/kg) or glibenclamide (10 mg/kg) or 0.5mL acacia solution (2 %w/v) for 15 days. Blood was collected on days 0, 3, 5, 7, 9, 11, 13, 15 for glucose estimation. In postprandial test, three extract groups (100, 250 and 500 mg/kg) and the control were arranged, each comprised of 5 rats. Each animal was administered orally with glucose at a dose of 2g/kg bwt followed by extract administration 30min later. Blood glucose was monitored at 30, 60 and 120 min intervals. In hypoglycaemic study, the extract was administered at doses of 100, 250 and 500 mg/kg bwt. Lipid profile was analyzed by modified enzymatic procedure and glycated haemoglobin (HbA1C) by standard protocol. Results: The diabetic rats treated with the extract/glibenclamide showed weight gain. They also experienced dose (250 and 500 mg/kg bwt) dependent decrease in glycaemia with maximum decrease of 259.1±3.0 (24.9%) and 266.1±2.9 (25.3%) respectively while glibenclamide, 227.0±3.8 (36.0%). The postprandial test showed that the extract induced lower blood glucose level after 60 min. The extract also showed to have good hypoglycaemic activity at doses of 250 and 500 mg/kg bwt respectively. The pancreatic tissue analysis from the rats treated with the root extract indicated substantial beta cells survivor. An appreciable decrease in HbA1C level was found in the extract and glibenclamide treated compared to the negative control. In lipid profile study, Pseudocedrela kotschyi extract was observed to have ameliorated dyslipidaemia. Conclusion: The extract showed efficacy in attenuating hyperglycaemia, inducing hypoglycaemia and ameliorating dyslipidaemia.

Effect of Raphia hookeri Seed Extract on Blood Glucose, Glycosylated Haemoglobin and Lipid Profile of Alloxan Induced Diabetic Rats.

Aim: To examine the effect of Raphia hookeri (RH) seed extract on blood glucose, glycosylated haemoglobin and lipid profile of alloxan induced diabetic rats. Materials and Methods: In the oral glucose tolerance test (OGTT), the animals received the extract (1 g/kg) or glibenclamide (0.01 mg/kg) or vehicle and 30 min later they received oral glucose load (1 g/kg). Glucose was estimated at 30min, 1, 2, 3 and 4 h. In hypoglycaemic study, the extract was administered at doses of 100, 250 and 500 mg/kg body weight (bwt) doses. In fasting blood glucose study (FBG), diabetic Wister rats, 5 per group, received graded doses (50, 100 and 200 mg/kg) of the extract or glibenclamide (10 mg/kg) or vehicle for 15 days. Blood was collected on days 0, 3, 5, 7, 9, 11, 13, 15 for glucose estimation. Lipid profile was analyzed using modified enzymatic procedure. Insulin assay was done by Diagnostic Automation Kit and HbA1C by standard protocol. The studies lasted for three weeks. Results: The diabetic animals treated with the extract showed appreciable weight gain. In oral glucose tolerance test (OGTT), RH seed extract and glibenclamide treated rats blood glucose significantly (P<0.05) decreased in the peak values and the area under curve after 4 h of oral load with decreased values of 48.3±1.0 mg/dL (63.3%) and 62.0±0.8 mg/dL (51.6%) respectively. The hypoglycaemic activity at 250 and 500 mg/kg body weight (bwt) doses showed lowest plasma glycaemic decrease of 50.1% and 54.4% respectively after 8 h of oral administration. In FBG study, after 15 days of extract/glibenclamide treatment, the animals’ blood glucose exacerbated by alloxan challenge returned to normal glycaemia with glycaemic decrease of 87.2±2.3 (79.3%); 57.0±1.7 (86.3%) and 55.0±0.3 mg/dL (87.1%) respectively while glibenclamide showed a maximum glycaemic decrease of 167.4±1.1 mg/dL (60.1%). The tissue morphology of the extract treated showed significant beta cells survivor. The extract ameliorated dislipidaemia and exerted significant (p<0.05) decrease in plasma HbA1C while marked increase in plasma insulin level occurred. Conclusion: The extract effectively attenuated hyperglycaemia, caused marked decrease in HbAIC concentration and ameliorated dislipidaemia.

Metabolic and molecular action of Trigonella foenum-graecum (fenugreek) and trace metals in experimental diabetic tissues.

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.

Hypoglyceamic effects of aqueous extract of Aframomum Melegueta leaf on alloxan-induced diabetic male albino rats

Aframomum melegueta (Zingiberaceae) seeds are used in West Africa, as a remedy for variety of ailments such as stomach ache, snakebite, diarrhea and anti-inflammatory properties. The hypoglycaemic effects of crude leaf extract of Aframomum melegueta on the treatment of alloxan induced diabetes in male rats and non-diabetic rats (control) were examined in this study. Results obtained from the experiment showed that the elevated blood glucose level caused by oral administration of 250 mg / kg body weight of alloxan was reduced significantly (p < 0.01) by oral administration of Aframomum melegueta leaf extract doses of 50, 100 and 200 mg/kg with the exception of 20 mg/kg when compared to control groups. The non-diabetic groups that received the extract showed reduction in blood sugar level as the dose increases when compared to their control group. There was a final weight gain and organ restoration for both the diabetic and non-diabetic rats after treatment when compared with their controls. This study showed that the extract have hypoglycemic and prophylactic effects.

Effect of Alloxan-diabetic Rat Fed with Different Diets on Ureogenesis in Isolated Perfused Liver

The effect of alloxan-diabetic rat fed with normal, high fat, low protein and high protein diets on the rate of urea production and the activities of enzymes associated with the urea cycle (ornithine transcarbamoylase, E.C. 2.1.3.3, OTC; arginase, E.C. 3.5.5.1) have been studied in intact and isolated perfused liver. The amount of urea excretion was the highest in the high protein diet group. When each diet group was treated with alloxan, total urea excretion showed little differences between each diet group and its corresponding control group with the exception being in the normal diet group. However, the enzyme activity of OTC was increased significantly by alloxan treatment in low and high protein diet groups as compared to corresponding control groups. Similar results were obtained in arginase activity, although the magnitude of the change was less marked. In liver perfusion experiments on rats treated with alloxan, the amount of urea production and changes in OTC and arginase activity were very similar with those in the intact liver. These results suggest that alloxan treatment in normal diet group causes an increase in urea excretion both in intact and perfused liver regardless of changes in enzyme activities and total urea excretion, and enzyme activities are affected by changes in dietary components but the changes of enzyme activities may not correlate with total urea excretion.

Hexokinase isoenzymes in diabetes.

Hexokinase is present in the tissues in four isoenzymic forms. Cerebral tissue contains predominantly Type I hexokinase which is believed to be insulin-insensitive. In cerebral tissue about 60 to 70% of the hexokinase is bound to the particulate fraction. The changes in the distribution of hexokinase Type I and Type II together with the bound and free hexokinase have been studied in control, diabetic and diabetic animals treated with insulin. The results indicate that the presence of insulin is essential for the normal binding of the hexokinase to the particulate fraction. In heart tissue, Type II hexokinase bound to the pellet shows a significant decrease in diabetes, which is reversed on insulin administration.