Prophylactic effects of Combretum molle boughs on changes in the hematological, biochemical, and histological parameters in dexamethasone-induced insulin-resistant rats

Background: Combretum molle (Combretaceae) is a plant used in Cameroon traditional medicine to treat diabetes mellitus. To our knowledge, no studies have been performed on the preventive effects of C. molle on change in hematological, biochemical, and histological parameters of insulin-resistant rats. The aim of the study was to evaluate the preventive effect of C. molle on changes in the hematological biochemical, and histological parameters of insulin-resistant rats. Methods: Insulin resistance was induced for 10 days by subcutaneous injection of dexamethasone (1 mg/kg), one hour after oral pretreatment of animals with distilled water, metformin (40 mg/kg), and C. molle extract (250 and 500 mg/kg). Hematological profile (red blood cells, white blood cells, platelets and their indices), biomarkers of renal and hepatic function, hepatic glycogen level, activity of hepatic enzymes of carbohydrate metabolism, and histological sections of kidney, liver and pancreas were assessed. Results: C. molle extract (250 and 500 mg/kg) caused a significant decrease (p < 0.05 to p < 0.001) in white blood cells, platelets count, and the activities of fructose 6-diphosphatase, glucose-6-phosphate dehydrogenase, and transaminases. It also caused significant increase (p < 0.05 to p < 0.001) in red blood cells, hemoglobin, albumin, glycogen, urea, uric acid, and creatinine values, and fructose-1,6-diphospatase and glucokinase activity. Histological examination revealed regeneration of beta-cells of the pancreatic islets and preventive renal and hepatic tissues against damages caused by impact of dexamethasone. Conclusion: C. molle extract protected insulin-resistant patients from hematological, biochemical, and histopathological changes, there by validating the merits of the use of this plant in traditional medicine to treat diabetes mellitus and its complications

Antidiabetic effect of the mixture of Cissus polyantha and Rytigynia senegalensis in high-fat diet and streptozocin-induced diabetic rats

Background: In traditional Chinese medicine (TCM) practices, many plants of the Cissus and Rytigynia genera are used to treat many diseases including diabetes mellitus.The aim of this study was to evaluate the modulating effects of the mixture of the aqueous extracts of Cissus polyantha and Rytiginia senegalensis (CPRS) on some enzymes of carbohydrate metabolism, oxidative profile, and cardiovascular parameters in diabetic rats. Methods: Diabetes was induced by a diet enriched in high-fat for 30 days associated with a single intraperitoneal injection of streptozocin (35 mg/kg). Rats with a blood glucose level greater than or equal to 200 mg/dL were selected and divided into groups. Groups 1 and 2 received distilled water. Group 3 received metformin (40 mg/kg). Groups 4 and 5 received CPRS at doses of 50 and 111 mg/kg, respectively. Glycaemia, body mass, food and water intake, insulinemia, insulin resistance and insulin secretion indices, lipid profile and cardiovascular risk indices, oxidant profile, glycogen and liver enzymes were evaluated. Histology of the pancreas and heart was performed. Results: CPRS (50 and/or 111 mg/kg) significantly (p < 0.05 to p < 0.001) reduced water and food consumption, blood glucose, HOMA-IR, coronary risk index, cholesterol, triglyceride, LDL-c, VLDL-c, and malondialdehyde levels, as well as glucose-6-phosphatase and fructose-1,6-biphosphatase activities in diabetic animals. In contrast, CPRS (50 and/or 111 mg/kg) caused an increase (p < 0.05 to p < 0.001) in body mass, insulinemia and HDL-c levels, reduced glutathione and hepatic glycogen. HOMA-β, insulin distribution, atherogenic and cardioprotective indices as well as superoxide dismutase, catalase, glucokinase, and glucose-6-phosphate dehydrogenase activities were also increased after CPRS administration. CPRS regenerated pancreatic islet β cells and decreased leukocyte infiltration in cardiomyocytes of diseased animals. Conclusion: CPRS has hypoglycemic, antidyslipidemic, and antioxidant effects, thus validating its use in traditional medicine in the treatment of diabetes mellitus and its complications

Tapinanthus dodoneifolius leaf inhibits the activity of carbohydrate digesting enzymes and improves the insulin resistance induced in rats by dexamethasone

Background: Tapinanthus dodoneifolius is a plant used in traditional African medicine to treat diabetes mellitus. This study aimed to evaluate the preventive antidiabetic potential of the aqueous extract of T. dodoneifolius leaves (AETD) in insulin resistant rats. Methods: A quantitative phytochemical study of AETD was carried out to determine the contents of total phenols, tannins, flavonoids, and saponins. AETD was tested in vitro on the activity of α-amylase and α-glucosidase enzymes. Insulin resistance was induced for 10 days by daily subcutaneous injection of dexamethasone (1 mg/kg). One hour before, the rats were divided into 5 groups and treated as follows: group 1 received distilled water (10 mL/kg); group 2 received metformin (40 mg/kg), and groups 3, 4, and 5 were treated with AETD (125, 250, and 500 mg/kg). Body weight, blood sugar, food and water consumption, serum insulin level, lipid profile, and oxidative status were assessed. One-way analysis of variance followed by Turkey's post-test and two-way analysis followed by Bonferroni's post-test were used to analyze univariate and bivariate parameters, respectively. Results: Results showed that the phenol content of AETD (54.13 ± 0.14 mg GAE/g extract) was higher than that of flavonoids (16.73 ± 0.06 mg GAE/g extract), tannins (12.08 ± 0.07 mg GAE/g extract), and saponins (IC50 = 13.56 ± 0.03 mg DE/g extract). AETD showed a higher inhibitory potential on α-glucosidase activity (IC50 = 191.51 ± 5.63 μg/mL) than on α-amylase activity (IC50 = 1774.90 ± 10.32 μg/mL). AETD (250 and/or 500 mg/kg) prevented drastic loss of body weight and reduced food and water consumption in insulin resistant rats. The levels of blood glucose, total cholesterol, triglycerides, low-density lipoprotein cholesterol, and malondialdehyde were also reduced while high-density lipoprotein cholesterol level, reduced glutathion level, and catalase and superoxide dismutase activity increased after administration of AETD (250 and 500 mg/kg) in insulin resistant rats. Conclusion: AETD has significant antihyperglycemic, antidyslipidemic, and antioxidant potential, thus it can be used for the management of type 2 diabetes mellitus and its complications