title: The aqueous extract of Terminalia superba (Combretaceae) prevents glucose-induced hypertension in rats.
abstract: OBJECTIVE
  The stem bark of Terminalia superba (Combretaceae) (TS) is used in traditional Cameroonian medicine as antihypertensive remedy. The aim of this study was to investigate the hypotensive and the antihypertensive effects of the aqueous extract of the stem bark of Terminalia superba.
  
  
  METHODS
  Hypertension was obtained in rats by oral administration of 10% D-glucose for 3 weeks. The acute effects of Terminalia superba were studied on blood pressure (BP) and heart rate (HR) after intravenous administration in normotensive rats (NTR) and glucose hypertensive rats (GHR). The antihypertensive effects were studied after oral administration of the extract (50 and 100 mg/kg/day) or nifedipine (10 mg/kg/day) for 3 weeks. At the end of the experiment, BP and HR were measured and reduced glutathione (GSH), malondialdehyde (MDA) and superoxide dismutase (SOD) activity levels were measured in heart, aorta, liver and kidney.
  
  
  RESULTS
  Intravenous administration of the aqueous extract of Terminalia superba induced a significant hypotensive response without any change in HR. The hypotensive effect of the extract was unaffected by atropine or propranolol but decreased by reserpine (5 mg/kg) and yohimbine (0.1 mg/kg). In addition, the oral administration of the extract significantly prevented the rise in BP in glucose-hypertensive rats. Finally, the treatment with plant extract significantly blunted the decrease in GSH and the increase in MDA levels associated with hypertension, and significantly prevents the increase in aortic SOD activity.
  
  
  CONCLUSIONS
  The present study demonstrates that the aqueous extract of the stem bark of Terminalia superba exhibits hypotensive and anti-hypertensive properties that are, at least in part, related to a withdrawal of sympathetic tone and to an improvement of the antioxidant status, respectively. Overall data validate the use of Terminalia superba as antihypertensive therapy in traditional medicine.
authors.affiliation: Laboratoire de Physiologie Animale, Faculté des Sciences, Université de Yaoundé I, PO Box 812, Yaounde, Cameroon.
authors.forename: Esther Ngo Lemba
authors.initials: EN
authors.lastname: Tom
authors.forename: Céline
authors.initials: C
authors.lastname: Demougeot
authors.forename: Orelien Bopda
authors.initials: OB
authors.lastname: Mtopi
authors.forename: Théophile
authors.initials: T
authors.lastname: Dimo
authors.forename: Paul Désiré Dzeufiet
authors.initials: PD
authors.lastname: Djomeni
authors.forename: Danielle Claude
authors.initials: DC
authors.lastname: Bilanda
authors.forename: Corinne
authors.initials: C
authors.lastname: Girard
authors.forename: Alain
authors.initials: A
authors.lastname: Berthelot
mesh_terms: D000818:Animals; D000959:Antihypertensive Agents / Q000302:isolation & purification / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D002163:Cameroon; D020834:Ethnopharmacology; D005947:Glucose / Q000008:administration & dosage; D006339:Heart Rate / Q000187:drug effects; D006973:Hypertension / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D008297:Male; D016488:Medicine, African Traditional; D018384:Oxidative Stress / Q000187:drug effects; D008517:Phytotherapy; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology; D018547:Plant Stems / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry; D051381:Rats; D017208:Rats, Wistar; D029766:Terminalia / Q000737:chemistry
chemical_list: D000959:Antihypertensive Agents; D010936:Plant Extracts; D005947:Glucose