Effect of aqueous extract of Scorodophloeuszenkeri bark on chronic hyperglycemia and its complications in a diabetic Wistar rat model induced by streptozotocin

Diabetes and its complications represent a real major public health problem in the world because of its high rates of morbidity and mortality. Chronic hyperglycemia, oxidative stress, dyslipidemia and inflammation play a major role in the pathophysiology of diabetes and its vascular complications. The objective of this study was to evaluate the effect of aqueous extract of S. zenkeri on chronic hyperglycemia and its complications in a streptozotocin-induced diabetic Wistar rat model. The barks of S. zenkeri were washed, dried and crushed; the powder was dissolved in distilled water (1:10 weight/volume) then macerated and the filtrate obtained was dried in an oven. Subsequently, after quantification of the bioactive compounds (total polyphenols, flavonoids and alkaloids) present in the extract, an in vivo study was conducted in an animal model of streptozotocin-induced hyperglycemia. For this fact, the rats were divided into four groups of five rats as folow: a normoglycaemia group (NC), an untreated hyperglycaemia group (PC), two hyperglycaemia groups including a test group receiving by esophageal gavage, the aqueous extract of the bark of S zenkerii (AESZ) at a dose of 300 mg/kg body weight and a control group receiving metformin at a dose of 20 mg/kg body weight. During the treatment which lasted 21 days, the weights have been taken every two days and the blood sugar levels every week. At the end of the treatment, the rats were killed under light chloroform anesthesia; the plasma, hemolysate, serum and liver homogenate prepared were used to assay the biochemical parameters of oxidative stress (catalase, MDA), lipid profile (Triglycerides, total cholesterol and HDL-cholesterol) and immunological (CRP and NFS). It emerged that the extract limited weight loss and caused a reduction in blood sugar of −26.59% after 21 days of treatment; the extract caused an increase in the activity of erythrocyte catalase and a reduction in the concentration of hepatic MDA, as well as a very marked reduction in inflammatory cells and CRP. The extract also caused a reduction in dyslipidemiawhich was materialized by a reduction in CRR, AC, AIP and an increase in CPI. These results suggest that this extract contains bioactive compounds capable of reducing chronic hyperglycemia while preventing its complications, thus justifying its traditional use in the management of diabetes.