Renal and metabolic effects of tulbaghia violacea harv. and captopril in fructose-fed streptozotocin induced diabetic rats.
Loading...
Date
2017
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Background: Diabetes mellitus has rapidly emerged as a worldwide epidemic resulting in significant
morbidity and mortality. The incidence of type 2 diabetes mellitus, induced by a high carbohydrate diet,
a sedentary lifestyle as well as obesity, is increasing rapidly. Despite the availability of current
conventional drugs, the complications of diabetes mellitus continue to progress. Therefore the search
for alternate therapies that are antidiabetic in nature and elicit minimal side effects is essential. This
study investigated the effects of the medicinal plant Tulbaghia violacea. Harv and angiotensin
converting enzyme inhibitor, Captopril in a fructose-fed streptozotocin induced diabetic rat model.
Methods: Thirty-six, male Sprague-Dawley rats (six-week old) were randomly divided into six groups’
namely non-diabetic control, diabetic control, diabetic treated with Tulbaghia violacea Harv. (60 mg/kg
bw), diabetic treated with captopril (50 mg/kg bw), diabetic treated with metformin (250 mg/kg bw)
and diabetic treated with glibenclamide (10 mg/kg bw). Diabetes was induced by fructose feeding for
1 week followed by a single intraperitoneal injection of 40 mg/kg.bw streptozotocin. Animals with a
fasting blood glucose concentration >25mmol/L were considered diabetic and included in the study.
Thereafter, respective doses of Tulbaghia violacea and conventional drugs were daily administered to
the diabetic groups by oral gavage for seven weeks. At week six, an oral glucose tolerance test was
performed. At the end of week 7, the animals were euthanized by halothane overdose. Blood was
collected and organs were harvested for further biochemical analyses.
Results: Tulbaghia violacea treatment significantly increased plasma insulin and liver glycogen
content. Tulbaghia violacea treatment also reduced liver thiobarbituric acid reactive substances levels,
increased liver superoxide dismutase concentration and increased plasma nitric oxide levels.
Furthermore, Tulbaghia violacea administration reduced serum triglycerides, total cholesterol, VLDL
cholesterol, LDL cholesterol and increased HDL cholesterol. The plant treated group showed increased
pancreatic islet counts as well as improved glomerular morphology. The angiotensin converting enzyme
inhibitor captopril showed a significant increase in angiotensin converting enzymeactivity as well as
increased angiotensin type 1 receptor expression compared to the diabetic controls and Tulbaghia
violacea.
Conclusion: Tulbaghia violacea did not decrease fasting blood glucose levels or improve glucose
tolerance. However, in this study, the data obtained demonstrated the ability of Tulbaghia violacea to
elicit antioxidant and hypolipidemic effects, augment plasma insulin levels, improve pancreatic and
glomerular morphology and positively impact β- cell function in a fructose-fed streptozotocin induced
diabetic rat model.
Description
Master’s degree. University of KwaZulu-Natal, Durban.