Investigating the effects of bredemolic acid on selected markers of some prediabetes-associated dysfunctions in diet-induced prediabetic rats.

Doctoral Degree. University of KwaZulu-Natal, Durban.Prediabetes is an abnormal glycaemic state between normoglycaemia and chronic hyperglycaemia which is currently prevalent in developing and developed countries due to increased consumption of high caloric diet coupled with sedentary lifestyle. Prediabetes is associated with abnormal glucose metabolism. Additionally, the risk of developing prediabetes-associated complications such as non-alcoholic fatty liver disease (NAFLD), cardiovascular and renal diseases is not only present in overt diabetes mellitus but also in prediabetes. Management of prediabetes involves the combination of dietary and pharmacological interventions, however there is reported low compliance among patients as they tend to become overly dependent on the pharmacological interventions. Consequently, the pharmacological intervention efficacy is reduced as patients still progress to having overt diabetes. Therefore, managing prediabetes with anti-diabetic agents that will remain effective even in the absence of dietary intervention is considered necessary. Triterpenes have been found to have potential as anti-diabetic agents. Bredemolic acid (BA), a pentacyclic triterpene, has been reported to have increased biological activity relative to some other triterpenes. In this study, we sought to investigate the effects of BA on selected markers of some prediabetes-associated dysfunctions such as abnormal glucose homeostasis, hepatic, cardiovascular and renal dysfunctions in a prediabetic rat model in both the presence and absence of dietary intervention. Materials and Methods Thirty six (36) Sprague Dawley male rats that weighed 150 – 180g were divided into two groups: the non-prediabetic (n=6) and the prediabetic groups (n=30) which were fed a normal diet (ND) and high fat high carbohydrate (HFHC) diet respectively for 20 weeks to induce prediabetes. At 20th week, prediabetes was confirmed by assessment of fasting blood glucose (FBG) and oral glucose tolerance test (OGTT). The prediabetic rats were further sub-divided into five groups (n=6) and treated with either BA (80 mg/kg) or metformin (MET, 500 mg/kg) in the presence and absence of diet intervention for 12 weeks. Every 4 weeks of treatment, all the animals were placed in metabolic cages to determine caloric and fluid intake as well as urine output. Also, the body mass index (BMI), waist circumference (WC), blood pressure and heart rate were measured at every 4 weeks of treatment. After the 12 weeks of treatment, the animals were sacrificed, blood samples were collected into EDTA sample bottles and centrifuged to obtain plasma. Also, the skeletal muscle, liver, heart and kidney were collected, weighed, snapped frozen with liquid nitrogen and stored at -80°C before the biochemical analysis of selected markers of glucose homeostasis, hepatic, cardiovascular and renal functions. Results In the first study, the untreated diet-induced prediabetic rats had a significantly increased body weight, increased caloric intake, elevated glycated haemoglobin, increased ghrelin plasma concentration, decreased muscle glycogen concentration, insulin resistance and hyperinsulinaemia compared to the non-prediabetic rats. However, BA treatment with or without diet intervention ameliorated the body weight, caloric intake, glycated haemoglobin, muscle glycogen, glucose tolerance, plasma insulin and increased the expression of glucose transporter 4 (GLUT 4) in the skeletal muscle by comparison to the untreated prediabetic rats. Prediabetic induction in the second study resulted into elevated plasma concentration of liver enzymes, increased liver glycogen and triglyceride concentrations, increased oxidative stress in the liver and decreased sterol regulatory element binding protein (SREBP1c) by comparison to the non-prediabetic animals. Conversely, administration of BA with or without dietary intervention ameliorated liver functions by decreased oxidative stress, decreased liver enzymes, decreased liver glycogen and triglyceride as well as increased hepatic SREBP1c concentration in comparison to the untreated prediabetic animals. The results in the third study showed that the untreated prediabetic rats had a significantly increased body mass index (BMI), waist circumference (WC), blood pressure, heart rate, lipid profile, oxidative stress and inflammatory markers with significantly decreased endothelial nitric oxide synthase (eNOS) by comparison to the non-prediabetic control rats. On the other hand, the administration of BA with or without diet intervention improved cardiovascular functions by a decrease in BMI, WC, total cholesterol concentration, triglyceride concentration, blood pressure, heart rate, oxidative stress and inflammation with significant increase in eNOS plasma concentration in comparison to the untreated prediabetic rats. In the fourth study, the untreated prediabetic rats had a significantly increased fluid intake, urine output, sodium retention, potassium loss, aldosterone concentration, albuminuria, proteinuria, kidney injury molecule (KIM-1) and urinary podocin mRNA expression in comparison to non-prediabetic control and BA treated rats with or without diet intervention. Also, the untreated prediabetic rats presented increased albumin, total protein, urea, uric acid, creatinine and oxidative stress markers concentrations with a significant decrease in glomerular filtration rate (GFR). However, administration of BA with or without diet intervention attenuated oxidative stress, decreased urinary podocin mRNA expression and the aforementioned renal dysfunctions parameters. Conclusion This study showed that long term consumption of high caloric diet-induced prediabetes and resulted in abnormal glucose homeostasis, hepatic, cardiovascular and renal dysfunctions. Also, the results of this study showed that these dysfunctions are not only present during overt type 2 diabetes mellitus but already present at the prediabetic stage due to insulin resistance or hyperinsulinaemia that triggered oxidative stress in the physiological systems that we examined in this study. However, due to amelioration of insulin resistance via improved insulin sensitivity and earlier reported antioxidant activities that are common to all pentacyclic triterpenes, administration of BA significantly ameliorated the prediabetes-associated dysfunctions (abnormal glucose homeostasis, hepatic, cardiovascular and renal dysfunctions) with or without diet intervention in the prediabetic stage

Effects of aqueous extract of Basella alba leaves on haematological and biochemical parameters in albino rats

The effects of the aqueous leaf extract of Basella alba on haematological and biochemical parameters were studied in Wistar strain albino rats. Twenty four (24) Wistar strain albino rats were randomly distributed into four groups of six (6) rats each. Group I rats served as control and received 10 ml/kg of normal saline, while group II, III and IV received 60, 80 and 100 mg/kg of aqueous leaf extract of B. alba, respectively, for two weeks. Administration of the extract was done orally. At the end of the treatment period, haematological parameters (red blood cell count, white blood cell count, platelet count, packed cell volume and haemoglobin concentration) and biochemical parameters (alkaline phosphatase (ALP), alanine aminotransaminase (ALT) and aspartate aminotransaminase (AST)) were determined. The results showed that B. alba significantly increased (p < 0.05, 0.01) red blood cell count, white blood cell count, packed cell volume, haemoglobin concentration and platelet count. However, the extract significantly (p < 0.05, 0.01) reduced the activity of the liver enzymes such as ALP, ALT and AST. The decreases were dose dependent. In conclusion, adding B. alba leaves as part of daily diet may reduce anaemia and maintain good health.Key words: Basella alba, haematological parameters, biochemical parameters, albino rats

Virgin coconut oil dietary consumption ameliorates abnormal haemostatic parameters in diabetic rats

Introduction: Virgin coconut oil (VCO), a saturated fat, has been reported to have anti-diabetic properties and there is dearth of information on its potency to correct abnormal haemostatic parameters associated with diabetic patients. Objectives: Therefore, this study was carried out to investigate effect of VCO consumption on abnormal haemostatic parameters in diabetic rats. Materials & Methods: A total of fifteen (15) male rats weighing 200–250g were divided into three (3) experimental groups: Normal control group (Group I) and Diabetic control group (Group II), both fed on normal rat chow for 4 weeks, and the Diabetic test group (Group III) , fed on 10% VCO diet for 4 weeks. The Group II and Group III rats were injected alloxan (150mg/kg) intraperitoneally to induce diabetes. After 72 hours of injection, the blood glucose was determined to confirm hyperglycemia. At the end of the experiment, fibrinogen concentration, prothrombin, bleeding and clotting times were determined in the animals. Results: The results showed a significant increase in the fibrinogen concentration and prothrombin time of Group II compared to Group I and Group III. However, there was significant decrease in bleeding time of Group II when compared to that of Group I and Group III while the clotting time of Group II was significantly decrease compared to Group I. Conclusion: Thus, VCO normalizes abnormal haemostatic conditions in diabetic

Antidiabetic effect of aqueous extract of Basella alba leaves and metformin in alloxan-induced diabetic albino rats

The present study was carried out to evaluate the anti-diabetic effect of aqueous extract of Basella alba leaves in alloxan-induced diabetic albino rats. Thirty (30) male albino rats weighing 100 to 150 g were used for this work. The rats were randomly distributed into five groups containing six (6) rats per group. Group I rats served as the healthy control group and were neither induced with diabetes nor given any treatment. Group II rats served as the diabetic control. They were induced with diabetes but not given any treatment throughout the experiment. Rats in group III and IV were induced with diabetes and administered B. alba leaf extract at different doses, 100 and 200 mg/kg, respectively. Group V rats were also induced with diabetes and treated with Metformin at a dose of 100 mg/kg body weight. The various treatments were administered orally for a period of three weeks. The mean fasting blood glucose (FBG) of the rats was determined weekly using a glucometer. The rats treated with B. alba at doses of 100 and 200 mg/kg had their mean FBG levels significantly lower than the diabetic control group (p<0.05). Similarly, there was significant difference between rats in the group treated with Metformin and the diabetic control group (p<0.05). The mean FBG levels of rats treated with 200 mg/kg of B. alba leaf extract was not statistically different from that recorded in rats treated with Metformin. The results show that B. alba leaf extract has antidiabetic effect in alloxan-induced diabetic rats, varying with the quantity ingested. Hence, consumption of B. alba leaf as a vegetable should be encouraged for the treatment of diabetes mellitus.Keywords: Basella alba, diabetes mellitus, fasting blood glucose, metformin, hypoglycemia.African Journal of Biotechnology, Vol 13(24) 2455-245

Effects of an Ethanolic Leaf Extract of Gongronema latifolium on Haematological Some Parameters in Rats

In this study, the effect of ethanolic leaf extract of Gongronema latifolium on haematological parameters was investigated. In this study, twenty (20) albino Wistar rats were divided into 4 groups of 5 rats each. The control group was given 2ml of normal saline (orally) while the test groups were given orally; 175mg/kg (low dose), 350mg/kg (medium dose) and 500mg/kg (high dose) of Gongronema latifolium ethanolic leaves extract. The feeding regimens lasted for 14 days. After 14 days, blood samples were collected through cardiac puncture for haematological parameter analysis. The result showed that RBC (Red Blood Cell) counts significantly decreased in the low, medium and high dose groups (4.74±0.22, 5.52±0.13 and 4.54±0.07 x 106 cells/mm3 respectively) compared with the control group (7.90±0.31) at P<0.05. Also, significant decreases (P<0.05) in the level of the total WBC (White Blood Cell) count, platelet count, PCV (Packed Cell Volume) and Hb (haemoglobin) concentration were observed. The decreases were dose dependent. The MCH (Mean Corpuscular Haemoglobin) and MCHC (Mean Corpuscular Haemoglobin Concentration) except MCV (Mean Corpuscular Volume) significantly decreased in high dose group only. The results suggest that incessant consumption of the leaves of the plant may not advisable

Association between Altered Thyroid Function and Prediabetes in Diet-Induced Prediabetic Male Sprague Dawley Rats

There is a correlation between the existence of type 2 diabetes mellitus (T2DM) and the development of thyroid disorders. Prediabetes is a progressive state of moderate insulin resistance that often precedes the onset of T2DM. However, the association between prediabetes and thyroid function is unknown. This study assessed changes in markers of thyroid function in diet-induced prediabetes. Twelve male Sprague Dawley rats (n = 12) were randomly assigned into two groups. Rats in the non-prediabetic (NPD) group were fed a standard rat diet, while rats in the prediabetic (PD) were fed a high-fat high-carbohydrate diet for 20 weeks to induce prediabetes. Thereafter, fasting blood glucose levels were measured. Plasma samples were assessed for triiodothyronine (T3), thyroxine (T4), thyroxine peroxidase (TPO) antibody, insulin, and glycated hemoglobin (HbA1c) concentrations. The elevated blood glucose, HbA1c, and plasma insulin levels coincided with increased T3 and reduced T4 levels in the PD group when compared to the NPD group. There was also an increase in the concentration of TPO antibodies in the PD group. Additionally, there was a significant correlation between the thyroid hormone concentrations and HbA1c levels. In conclusion, these results indicated that there is a positive association between thyroid dysfunction and diet-induced prediabetes in rats

Dietary Consumption of Virgin Coconut Oil Ameliorates Lipid Profiles in Diabetic Rats

Virgin coconut oil (VCO) is a saturated fat with promising antidiabetic properties but its ameliorative effect on lipid profiles in diabetics is rarely reported. Therefore, in this study, a total of fifteen (15) male rats weighing 200–250 g were divided into 3 experimental groups (n=5). Group I (control) and Group II (diabetic control group) were fed a normal rat chow while Group III (diabetic test group) was fed a 10% VCO diet for 3 weeks. Group II and Group III were made diabetic by intraperitoneal injection of 150 mg/kg of alloxan. After 72 hours of injection, blood glucose was tested to confirm diabetes mellitus. After 3 weeks, the animals were sacrificed to collect blood samples for lipid profile analysis. The results showed a significant increase in concentrations of triglyceride, total cholesterol, low density lipoprotein, and very low density lipoprotein and decrease in concentration of high density lipoprotein in Group II when compared to Group I. Also, the concentrations of triglyceride, total cholesterol, low density lipoprotein, and very low density lipoprotein except high density lipoprotein significantly reduced in Group III when compared to Group II (P<0.01, 0.001). VCO consumption can be claimed to ameliorate lipid levels in diabetes mellitus

Bredemolic Acid Improves Cardiovascular Function and Attenuates Endothelial Dysfunction in Diet-Induced Prediabetes: Effects on Selected Markers

Prediabetes is an intermediate hyperglycaemic state which has been associated with cardiovascular dysfunction. However, cardiovascular dysfunction is not only caused by intermediate hyperglycaemia but also endothelial dysfunction, inflammation, and oxidative stress associated with prediabetes. Bredemolic acid (BA), an isomer of maslinic acid, has been reported to ameliorate the intermediate hyperglycaemia found in prediabetes; however, the effects of this triterpene on cardiovascular function have not yet been determined. Therefore, this study investigated the effects of BA on cardiovascular function in diet-induced prediabetic rats. Thirty-six male rats that weighed 150–180 g were divided into two groups, the non-prediabetic (n = 6) and the prediabetic groups (n = 30), which were fed normal diet (ND) and HFHC diet, respectively. The prediabetic rats were further subdivided into five groups (n = 6) and treated with either BA (80 mg/kg) or metformin (MET, 500 mg/kg) every third day for 12 weeks. After 12 weeks, blood samples and the heart were collected for biochemical analysis. The untreated prediabetic rats showed a significant increase in body mass index (BMI), waist circumference (WC), blood pressure, heart rate, lipid profile, lipid peroxidation, and inflammatory markers with significant decrease in endothelial function and antioxidant biomarkers by comparison with the non-prediabetic animals. The administration of BA significantly improved cardiovascular functions such as blood pressure, heart rate, and endothelial function. There was also a significant decrease in BMI, WC, lipid profile, lipid peroxidation, and inflammation with a concomitant increase in antioxidant capacity. BA administration improved cardiovascular function by attenuation of oxidative stress, inflammatory, and endothelial dysfunction markers