Orelien Sylvain Bopda Mtopi

Publications (5) View all

• Source

  Available from: Corine Girard-Thernier

  Dataset: Terminalia glucose JEP

  Esther Ngo Lemba Tom, Céline Demougeot, Orelien Bopda Mtopi, Théophile Dimo, Paul Désiré Dzeufiet Djomeni, Danielle Claude Bilanda, Corinne Girard, Alain Berthelot
• Source

  Available from: Corine Girard-Thernier

  Article: The aqueous extract of Terminalia superba (Combretaceae) prevents glucose-induced hypertension in rats.

  Esther Ngo Lemba Tom, Céline Demougeot, Orelien Bopda Mtopi, Théophile Dimo, Paul Désiré Dzeufiet Djomeni, Danielle Claude Bilanda, Corinne Girard, Alain Berthelot
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  ABSTRACT: 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. 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. 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. 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.
  Journal of ethnopharmacology 11/2010; 133(2):828-33. · 2.32 Impact Factor
• Article: Cardiodepression as a possible mechanism of the hypotensive effects of the methylene chloride/methanol leaf extract of Brillantaisia nitens Lindau (Acanthaceae) in rats

  Orelien Sylvain Mtopi Bopda, Theophile Dimo, Ives Seukep Tonkep, D Louis Zapfack
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  ABSTRACT: Brillantaisia nitens Lindau (Acanthaceae) is traditionally used in Cameroon for the management of many diseases including cardiovascular disorders. The aim of this study was to demonstrate the contribution of cardiodepressive activity of methylene chloride/methanol leaf extract of B. nitens to its hypotensive action in normotensive (NTR) and deoxycorticosterone acetate-salt hypertensive rats (DSHR). In this study, we used the direct cannulation method for blood pressure measurements and electrodes for electrocardiogram (ECG). In NTR, the systolic blood pressure dropped by 12.6, 13.8, 22.5 and 39.3% at the doses 5, 10, 20 and 40 mg/kg, respectively. In DSHR, systolic blood pressure decreased by 13.8, 16.2, 16.3 and 20.4% at the same doses, respectively. B. nitens extract (40 mg/kg) produced a significant reduction of the heart activity while the blood pressure rapidly dropped. At this same dose in NTR, B. nitens induced a negative chronotropic effect by causing a 20.59% (p<0.05) R-R interval elongation. More also, On P wave and T wave magnitude, the plant extract at the same dose induced a significant (p<0.05) decrease of 21.05 and 15.79%, respectively. For DSHR, B. nitens extract (40 mg/kg) induced significant changes on T wave duration, R-R interval and P wave magnitude. B. nitens extract decreased T wave duration by 44.44% (p<0.05), increased R-R interval by 100% (p<0.01) and decreased P wave magnitude by 20% (p<0.05). These results confirm our previous findings that the immediate hypotensive effect of B. nitens is partly due to its depressive effect on the cardiac pump.
  AFRICAN JOURNAL OF BIOTECHNOLOGY 01/2011; · 0.57 Impact Factor
• Source

  Available from: Télesphore Benoît Nguelefack

  Article: Vasorelaxant effects of Brillantaisia nitens Lindau (Acanthaceae) extracts on isolated rat vascular smooth muscle.

  T Dimo, O-S Bopda Mtopi, T B Nguelefack, P Kamtchouing, L Zapfack, E A Asongalem, E Dongo
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  ABSTRACT: Brillantaisia nitens Lindau (Acanthaceae) is traditionally used in Cameroon for the treatment of many diseases including cardiovascular disorders. We have studied its vasorelaxant effects in rat vascular smooth muscle. In this study, aqueous, methylene chloride, methanol, and methylene chloride/methanol leaves extracts of Brillantaisia nitens were tested for their relaxing ability in vitro. Strips of rat aorta, with or without intact endothelium, were mounted in tissue baths, contracted with KCl (60mM) or norepinephrine (10(-4)M), and then exposed to the plant extracts. These extracts exhibited concentration-dependent vasorelaxations of norepinephrine-induced contractions of intact aortic strips. The EC(50) were 0.42+/-0.01mg/ml (aqueous extract), 0.63+/-0.02mg/ml (methylene chloride extract), 0.73+/-0.02mg/ml (methanol extract) and 0.36+/-0.02mg/ml (methylene chloride/methanol extract). The methylene chloride/methanol (CH(2)Cl(2)/CH(3)OH) extract was the most potent relaxing extract. It caused a concentration-dependent and endothelium-independent relaxation of the rat aortic strips contracted by KCl or norepinephrine. On the NE-induced contraction, its maximal relaxant activity (109%) due to the dose of 1.5mg/ml, was not significantly modified by the pretreatment of aortic strips with indomethacin (89%, P>0.05) or with l-NAME (103%, P>0.05). This suggests that the vasorelaxation elicited by CH(2)Cl(2)/CH(3)OH extract was not mediated via endothelium-derived prostacyclin or nitric oxide. In contrast, this relaxation was markedly reduced by tetraethylammonium, a blocker of non-selective K(+) channels and glibenclamide, a blocker of ATP-sensitive K(+) channels. The CH(2)Cl(2)/CH(3)OH extract significantly inhibited Ca(2+)-induced concentration-contraction and the Ca(2+) influx in aortic strips incubated with 60mM KCl. These results indicate that the vasorelaxant effect of the CH(2)Cl(2)/CH(3)OH extract of Brillantaisia nitens is due to an inhibition of Ca(2+) influx, possibly via the activation of ATP-sensitive K(+) channels.
  Journal of Ethnopharmacology 05/2007; 111(1):104-9. · 3.01 Impact Factor
• Article: EFFECTS OF BRILLANTAISIA NITENS LINDAU (ACANTHACEAE) METHYLENE CHLORIDE/METHANOL LEAF EXTRACT ON RAT ARTERIAL BLOOD PRESSURE AND HEART RATE

  Bopda Mtopi O.S.a, Dimo T., D. Nguelefack T.B.
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  ABSTRACT: Brillantaisia nitens Lindau (Acanthaceae) is traditionally used in Cameroon for the treatment of many diseases including cardiovascular disorders. We have studied the effect of the methylene chloride/methanol (CH2Cl2/CH3OH) leaf extracts of B. nitens on rat arterial blood pressure and heart rate in normotensive wistar rats (NTR), salt laoded hypertensive rats (SLHR), DOCA-salt hypertensive rats (DSHR) and L-NAME hypertensive rats (LNHR), using the direct cannulation method. Intravenous (i.v.) administration of the plant extract (5-80 mg/kg) resulted in a biphasic dose-related hypotensive effect. At the dose of 10 mg/kg, the extract produced a rapid decrease of systolic blood pressure (SBP) by 14%, 16%, 14% and 23% in NTR, SLHR, DSHR and LNHR, respectiveley. In the same animal models, the dose of 40 mg/kg caused decreases of 39%, 26%, 20%, and 34%, respectively. The immediate fall of SBP induced by the plant extract was followed at higher doses by a sustained antihypertensive response. The most remarkable antihypertensive effect of the plant extract (40 mg/kg) was up to 31%, 60 min after i.v. injection in LNHR. B. nitens extract (40 mg/kg) produced a significant reduction of the heart rate by 13% and 29% in NTR and DSHR, respectively. The initial hypotensive effect induced by the plant extract was partially inhibited by atropine and reserpine while the late fall in blood pressure was partially reduced by propranolol and reserpine. These results suggest that the rapid and the late hypotensive activity of B. nitens might be due, respectively, to its depressive effect on the cardiac pump and to its vasorelaxant effect.
  Pharmacologyonline 1 :495-510. 01/2007;