Effects of stem bark aqueous extract of Fagara tessmannii Engl (Rutaceae) on cardiovascular risks related to monosodium glutamate-induced obesity in rat: In vivo and in vitro assessments.

ETHNOPHARMACOLOGICAL RELEVANCE: Fagara tessmannii is a shrub of the African rainforests in South-West, Centre, South and East provinces in Cameroon. It is used in traditional medicine for the treatment of tumors, swellings, inflammation, gonorrhoea, schistosomiasis, antifungal, heart diseases and as anti-hypertensive. AIM OF THE STUDY: We investigated the potential effects of F. tessmannii on cardiovascular risk related to monosodium glutamate-induced obesity. MATERIALS AND METHODS: Monosodium glutamate (MSG, 4 mg/g/day) was injected subcutaneously to newborn Wistar rats for the four consecutive first days of their life and on the 6th, 8th and 10th day after birth. After 21 weeks, obese rats were treated orally with F. tessmannii (100 or 200 mg/kg/day), orlistat (10 mg/kg/day) or telmisartan (10 mg/kg/day) for 6 weeks. Body weight, obesity, body mass index (BMI), Lee index, insulin sensitivity and glucose tolerance, blood pressure, lipid profile as a Coronary Risk Index (CRI), and reactivity of isolated thoracic aorta were evaluated. RESULTS: In addition to significantly decrease body weight (17.60% and 20.34%), BMI, Lee's index, retroperitoneal fat, total adiposity, and coronary risk indicators, F. tessmannii has significantly decreased insulin resistance and hyperglycemia and high blood pressure observed in MSG-obese rats. The high contractility to phenylephrine as well as the hypersensitivity to sodium nitroprusside (a nitric oxide-donor), observed in MSG aortic rings were significantly reduced by the F. tessmannii extract. Enhanced serum Na+ and Cl- levels and decreased K+ observed in obese rats were also significantly reversed after F. tessmannii treatment. CONCLUSIONS: F. tessmannii fights against obesity and associated cardiovascular risks by modulating production and vascular responsiveness to vasoactive factors, monitoring premature aging. F. tessmannii promotes the loss of ectopic fat and other fatty tissues, the sensitivity of the peripherical tissues to insulin, the energy expenditure and the renovascular decompression and regulates ions movement which prevents hypertension.

Antihypertensive and antidiabetic activities of Erythrina senegalensis DC (Fabaceae) stem bark aqueous extract on diabetic hypertensive rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Erythrina senegalensis is traditionally used in Cameroon for its relaxing and hypoglycemic properties in the treatment of cardiovascular diseases and diabetes. AIM OF THE STUDY: High blood pressure and diabetes mellitus are frequently linked. These pathologies represent major risk factors for cardiovascular and renal diseases. The present study was designed to evaluate the antidiabetic and antihypertensive activity of the stem bark of Erythrina senegalensis aqueous extract in male hypertensive diabetic rats (HDR). MATERIALS AND METHODS: Hypertension and diabetes were induced by oral administration of sucrose (15%) and ethanol (40°) at doses of 1.5 g/kg and 5 g/kg respectively for 30 days, followed by an intravenous injection of streptozotocin (STZ; 40 mg/kg). A control group of 5 rats received distilled water (10 mL/kg) followed by intravenous injection of 0.9% NaCl (1 mL/100 g). HDR were divided into 4 groups of 5 rats each according to their blood glucose level and continued to receive ethanol in association with: distilled water (10 mL/kg); group I, metformin (200 mg/kg)+nifedipine (10 mg/kg); group II, plant extract (100 and 200 mg/kg) group IV and V, respectively for 28 days. At the end of the treatment, hemodynamic parameters were recorded by the direct method. Animals were sacrificed; blood and organs (aorta, heart, liver, and kidneys) were collected for biochemical and histological analysis. Phytochemistry and HPLC-DAD-HRESI-MS were used to determine the major compounds of the extract. RESULTS: The administration of sucrose, alcohol, and STZ resulted in a significant increase in blood glucose, hemodynamic parameters, and body weight loss. A significant decrease in pancreatic islets size, nitrite, GSH, SOD and catalase activity was observed in HDR. There was also a significant increase in serum triglycerides, total cholesterol, creatinine, bilirubin, and transaminases activity in HDR. The aqueous extract of E. senegalensis, as well as the metformin + nifedipine combination, significantly improved all these parameters. HPLC coupled to both diode array and mass spectrometry detectors revealed the presence of 15 compounds and 11 of them were identified. CONCLUSION: These results suggest that the aqueous extract of E. senegalensis possess antihypertensive, hypoglycemic, hypolipidemic, cardiomodulator and antioxidant properties involved in the improvement of the metabolic disorders found in HDR. This may be due at least in part to the presence of Erysenegalensein (D, O, N, E), Warangalone, senegalensin and 6,8-diprenylgenistein identified in the extract.

Antihypertensive Activity of Leersia hexandra Sw. (Poaceae) Aqueous Extract on Ethanol-Induced Hypertension in Wistar Rat.

Leersia hexandra (L. hexandra) is used in traditional medicine to treat many diseases including hypertension. This study aimed to evaluate the curative effects of the aqueous extract of L. hexandra on hypertension. Hypertension was induced in rats by oral administration of ethanol (5 g/kg/day) for five weeks. The animals were divided into 2 groups: one group of 5 rats receiving distilled water (10 mL/kg) and another group of 20 rats receiving ethanol. At the end of the 5 weeks of administration of ethanol, the animals were divided into 4 groups of 5 rats each: one group of hypertensive rats receiving distilled water (10 mL/kg), another one receiving nifedipine (10 mg/kg), and two groups of hypertensive rats receiving L. hexandra at doses of 100 and 200 mg/kg, respectively. The results showed that ethanol induced a significant increase in the mean arterial pressure (MAP) and heart rate of normotensive rats. The administration of the extract (100 and 200 mg/kg) or nifedipine caused a significant decrease of MAP compared to hypertensive rats. Ethanol induced a significant increase of lipid profile, the atherogenic index, creatinine, and transaminase activities. Ethanol also induced a significant decrease in serum HDL-cholesterol and antioxidant markers evaluated. Treatment of hypertensive rats with L. hexandra or nifedipine significantly improved lipid profile, hepatic and renal functions, and antioxidant status. The curative effect of L. hexandra extract on hypertension is probably related to its antihypertensive, hypolipidemic, and antioxidant activities, which justifies its empirical use in the treatment of hypertension.