ABSTRACT
Backgroud: Erigeron floribundus is a herbaceous plant used in traditional Cameroonian medicine to treat diabetes mellitus. The aim of this study was to evaluate the antidiabetic properties of the aqueous extract of E. floribundus leaves (AEEF) in diabetic rats. Methods: Diabetes was induced by a single intraperitoneal injection of streptozotocin (60 mg/kg) in normal rats fasted for 16 h. Subsequently, 30 diabetic male rats were divided into groups and treated orally for 21 days with distilled water (10 mL/kg), glibenclamide (3 mg/kg) and AEEF (300, 400, and 500 mg/kg). Body weight, food and water intake, blood glucose, insulin levels, lipid and oxidative profiles, as well as some markers of liver and kidney function were assessed. Histological sections of the rats' pancreas were taken. Results: AEEF and glibenclamide significantly increased (p < 0.001) body weight and decreased food and water intake in rats. A decrease in blood glucose (p < 0.001) and an increase in insulin levels (p < 0.001) were observed in the AEEF and glibenclamide groups. AEEF caused a significant (p < 0.001) decrease in the levels of total cholesterol, LDL-c, triglycérides and coronary risk index (CRI), accompanied by a significant (p < 0.001) increase in HDL levels and HOMA-ß in rats. AEEF showed an improvement (p < 0.001) in CAT and SOD activity and GSH levels accompanied by a significant decrease (p < 0.001) in malondialdehyde levels. In addition, ALAT and ASAT activity, urea and creatinine levels were significantly reduced (p < 0.001) after treatment with AEEF and glibenclamide. The extract also improved the size of Langerhans Islets in the pancreas of diabetic rats. Conclusion: AEEF contains several bioactive compounds conferring antidiabetic, anti-dyslipidemic and antioxidant properties, thus justifying its therapeutic use in the treatment of diabetes mellitus.
ABSTRACT
AIM OF THE STUDY: Allanblackia floribunda Oliv. (Clusiaceae), an evergreen tree of the rain-forest has long been used in traditional African medicine to treat hypertension. The aim of this study was to evaluate the protective effect of Allanblackia floribunda aqueous extract on alcohol- and sugar-induced hypertension in rats. MATERIAL AND METHODS: Alcohol-induced hypertensive rats (AHR) were obtained by oral administration of ethanol (3g/kg/day) while sucrose (5, 6 and 7% in drinking water) was used for sucrose-induced hypertensive rat (SuHR). Both models of animals concomitantly received either aqueous extract (200 or 400mg/kg; p.o.) or nifedipine (10mg/kg; p.o.) all along the 8 weeks of experiment. Blood pressure and heart rate were measured using the direct cannulation method. The effects of the plant extract on lipid profile, oxidative stress markers, as well as on kidney and liver functions were evaluated at the end of the treatment by the colorimetric method. RESULTS: At the doses of Allanblackia floribunda (200 and 400mg/kg/day) significantly prevented (21.74; 26.65% and 11.71; 24.58% of reduction) the increase in mean blood pressure on AHR and SuHR, respectively. Administration of the plant extract at the dose of 400mg/kg led to the prevention of total cholesterol (42.82%), HDL-cholesterol (36.59%) and triglycerides (9.67%) increase in serum lipid in AHR as compared to the untreated AHR. In SuHR, the extract significantly prevented the high concentrations of total cholesterol (44.08%) and triglycerides (33.05%) induced by sucrose treatment as compared to the untreated SuHR, without affecting that of HDL-cholesterol. Allanblackia floribunda (200 and 400mg/kg) also prevented the increase in atherogenic index by 54.45 and 42.94% in AHR and by 23.70 and 44.32% in SuHR, respectively. Allanblackia floribunda (400mg/kg) prevented the increase in bilirubine (19.59 and 16.56%), urea (33.36 and 28.2%), ALT (29.55 and 33.09%) and AST (36.28 and 37.12%) of AHR and SuHR, respectively. Treatment with plant extract significantly prevented the increase of superoxide dismutase (SOD), malondialdehyde (MDA) and catalase and the decrease of reduced glutathione (GSH) concentration in aorta, heart, kidney and liver of AHR and SuHR. CONCLUSION: These results demonstrate that the aqueous extract of Allanblackia floribunda can prevent alcohol- and sugar-induced hypertension and oxidative stress in rats. These findings could therefore justify its use in traditional medicine.
