Cardiovascular effects of Helichrysum ceres S Moore [Asteraceae] ethanolic leaf extract in some experimental animal paradigms - PubMed (original) (raw)

. 2008 Sep-Oct;19(5):246-53.

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Cardiovascular effects of Helichrysum ceres S Moore [Asteraceae] ethanolic leaf extract in some experimental animal paradigms

Cephas T Musabayane et al. Cardiovasc J Afr. 2008 Sep-Oct.

Abstract

The aim of this study was to examine some in vivo and in vitro cardiovascular effects of Helichrysum ceres leaf ethanolic extract (HCE) in experimental animal paradigms. The acute effects of HCE on blood pressure were studied in anaesthetised normotensive male Wistar rats challenged with intravenous hypotonic saline infusion after a 3.5-hour equilibration for four hours of one-hour control, 1.5-hour treatment and 1.5-hour recovery periods. HCE was added to the infusate during the treatment period. Sub-chronic hypotensive effects of HCE were examined in weanling Dahl saltsensitive (DSS) genetically hypertensive rats, which progressively develop hypertension with age, treated with HCE (80 mg/kg) every third consecutive day for seven weeks. Isolated atrial muscle strips, portal veins and descending thoracic aortic rings of healthy normotensive Wistar rats were used to investigate the vascular effects of HCE. Acute HCE administration caused a significant (p < 0.05) fall in blood pressure in the normotensive anaesthetised Wistar rats. DSS hypertensive rats treated with HCE displayed low arterial blood pressure and heart rate values from weeks five to seven. HCE produced concentrationdependent negative inotropic and chronotropic effects on rat isolated electrically driven left, and spontaneously beating right atrial muscle preparations, respectively. HCE also evoked concentration-dependent relaxation responses of endothelium-intact aortic rings and portal veins isolated from healthy normotensive Wistar rats. The vasorelaxant effects of HCE in intact aortic rings were significantly reduced, but not completely abolished by adding endothelial- derived factor (EDRF) inhibitor, L-NAME, suggesting that the vasorelaxant effect of the extract is mediated via EDRF-dependent and independent mechanisms. The results of the study suggest that the hypotensive action of HCE is elicited, in part, directly by decreasing myocardial contractile performance and total peripheral vascular resistance due to its negative inotropic and chronotropic effects on rat isolated atrial muscle strips; and vasorelaxant effects on isolated vascular smooth muscles. The observed cardiovascular effects of HCE partly support the basis for its use in the management of high blood pressure in folkloric medicine.

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Figures

Fig. 1.

Fig. 1.

Blood pressure and heart rate effects in acutely treated anaesthetised Wistar rats (A, B) and chronically treated DSS rats (C, D). Values are means ± SEM, (n = 8 in each group). ★p < 0.05 by comparison with control.

Fig. 2.

Fig. 2.

Concentration-dependent response curves showing the cardio-inhibitory effects of HCE (10–160 mg/ml) on the rate (A) and force (B) of myocardial contraction in the absence and presence of atropine (1 μM). Values are means ± SEM, (n = 8; for each concentration). ★p < 0.05 by comparison with control ; *p < 0.05 by comparison with HCE alone.

Fig. 3.

Fig. 3.

Antagonistic effects of HCE (40 and 80 mg/ml) on the positive inotropic effects of noradrenaline (A) and CaCl2 (B). Values are means ± SEM, (n = 8 for each concentration). *p ≤ 0.05 by comparison with NA or CaCl2; ★p ≤ 0.05 by comparison with 40 mg/ml HCE.

Fig. 4.

Fig. 4.

Effects of HCE (10–160 mg/ml) on rat denuded endothelium and intact aortic rings pre-contracted with ME (A); endothelium-intact aortic rings pre-contracted with ME in the presence of EDRF antagonists (B); and intact rings pre-contracted with low K+ (20 mM) and high K+ (80 mM) concentrations in the presence of glibenclamide (C). All control rings were pre-contracted with ME. Values are means ± SEM, (n = 8; for each concentration). ★p < 0.05 by comparison with control; *p < 0.05 by comparison with HCE alone.

Fig. 5.

Fig. 5.

Contractile effects of HCE (10, 40 and 160 mg/ml) on rhythmic myogenic spontaneous contractions of rat portal veins (A); and HCE (160 mg/ml) in the presence of atropine (1 μM) (B). Values are means ± SEM, (n = 8; for each concentration). ★p < 0.05 by comparison with control; *p < 0.05 by comparison with HCE alone.

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References

    1. Myers MG, Harris L. Kalant H. Principles of Medical Pharmacology. 4th edn. New York: Oxford University; 1985. Antiarrhythmic drugs. pp. 411–424.
    1. Osim EE, Mbajiorgu EF, Mukarati G, Makufa B, Munjeri O, Musabayane CT. Hypotensive effect of crude extract of Olea africana (Oleaceae) in normotensive and hypertensive rats. Cent Afr Med J. 1996;45:269–274. - PubMed
    1. Somova IL, Shode FO, Nadar A, Ramnanan P. Antihypertensive, antiatheroscleritic and antioxidant activity of triterpenoids isolated from Olea europaea, subspecies africana leaves. J Ethnopharmacol. 2003;84:299–305. - PubMed
    1. Miller AL. Botanical influences on cardiovascular disease. Altern Med Rev. 1998;3(6):422–431. - PubMed
    1. Van Wyk B-E, Van Oudtshoorn B, Gericke N. Medicinal Plants of South Africa. 2nd edn. Pretoria: Briza; 2002. p. 148.

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