Pharmacological mechanisms involved in the vasodilator effects of extracts from Echinodorus grandiflorus

Tibiriçá, Eduardo; Almeida, Andressa Luiza Figueiredo; Caillleaux, Solange; Pimenta, Daniel S.; Kaplan, Maria Auxiliadora Coelho; Lessa, Marcos Adriano; Figueiredo, Maria Raquel

doi:10.1016/j.jep.2006.10.030

Cited by 31 publications

(27 citation statements)

References 16 publications

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“…For this purpose, we incubated the endothelium-intact PE-precontracted aortic rings with methylene blue which blocks the soluble guanylate cyclase. It is widely accepted that soluble guanylate cyclase activation is one of the most important effectors of NO synthesis/release in the cardiovascular system (Vanhoutte, 1989;Hansen and Nedergaard, 1999;Ajay et al, 2007;Tibiriç á et al, 2007). Our results showed that methylene blue significantly attenuated the vasorelaxant properties of NBF-LFME.…”

Section: Discussionsupporting

confidence: 52%

“…It is well known that the vascular endothelium plays an essential role in the regulation of the cardiovascular system, mainly in the control of vasomotor tone, via synthesis/release of vasodilator substances such as NO and prostacyclin (Vanhoutte, 1989;Tibiriç á et al, 2007). Accordingly, the role of the presence and absence of endothelium in the mode of action of NBF-LFME was the first to be investigated.…”

Section: Discussionmentioning

confidence: 99%

“…A reduced NO production by vascular endothelial cells is closely associated with endothelial dysfunction or injury, which is proposed to be an important factor in cardiovascular diseases, especially in the development of atherosclerosis and hypertension (Busse and Fleming, 1996;Tibiriç á et al, 2007). Therefore, in order to determine whether part of the relaxant effect elicited by NBF-LFME in isolated rat aortic rings may be due to NO release, we incubated the endothelium-intact PE-precontracted rings with l-NAME, a competitive inhibitor of NOS.…”

Section: Discussionmentioning

confidence: 99%

“…The involvement of the vasodilator cyclooxygenase (COX) products (prostacyclin PGI 2 ) was also investigated in intact aortic ring preparations that were preincubated with indomethacin, nonselective COX inhibitor (Tibiriç á et al, 2007). The inhibition of PE-induced contraction brought about by NBF-LFME was partially but significantly attenuated by indomethacin pretreatment.…”

Section: Discussionmentioning

confidence: 99%

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Pharmacological mechanisms underlying the vascular activities of Loranthus ferrugineus Roxb. in rat thoracic aorta

Ameer

Salman

Siddiqui

et al. 2010

Journal of Ethnopharmacology

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Section: Discussionsupporting

confidence: 52%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Pharmacological mechanisms underlying the vascular activities of Loranthus ferrugineus Roxb. in rat thoracic aorta

Ameer

Salman

Siddiqui

et al. 2010

Journal of Ethnopharmacology

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“…In fact, extracts from leaves of E. grandiflorus elicit an endothelium‐dependent, nitric oxide and PAF receptor‐mediated vasodilation in rabbit aortic rings. This potent vasodilator effect of the extracts was also demonstrated in the isolated rabbit renal circulation [9]. On the other hand, in vivo cardiovascular effects of extracts from E. grandiflorus are not known until now.…”

Section: Introductionmentioning

confidence: 82%

Antihypertensive effects of crude extracts from leaves of Echinodorus grandiflorus

Lessa

Araujo

Kaplan

et al. 2008

Fundamemntal Clinical Pharma

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The antihypertensive action of a crude ethanolic extract (EEEG) from leaves of Echinodorus grandiflorus (Alismataceae) was investigated in spontaneously hypertensive rats. The intraperitoneal injection of increasing doses of EEEG (300-1000 mg/kg) elicited dose-dependent reductions in mean arterial pressure (MAP) that were paralleled by reductions of cardiac output and systemic vascular resistance, reaching the maximum of 23 +/- 5%, 13 +/- 3% and 18 +/- 4%, respectively (n = 5, P < 0.05). Comparable reductions of MAP were obtained upon i.v. administration of EEEG (3-100 mg/kg), reaching the maximum decrease of 51 +/- 6% (n = 7; P < 0.001). The blockade of nitric oxide synthesis significantly reduced the hypotension induced by i.v. administration of EEEG. Moreover, the pre-treatment of the animals with a selective antagonist of cholinergic muscarinic receptors or of platelet-activating factor (PAF) receptors partially blunted the cardiovascular effects of EEEG. The i.v. pre-treatment with the selective B(2) bradykinin receptor antagonist HOE 140 or with indomethacin, an inhibitor of the enzyme cyclooxygenase, did not prevent the hypotensive effects induced by EEEG. Finally, the chronic oral treatment with EEEG presented a significant antihypertensive effect that was comparable to that of reference antihypertensive drugs currently used to treat arterial hypertension. It is concluded that EEEG elicits significant acute antihypertensive effects through the release of nitric oxide and the stimulation of cholinergic muscarinic and PAF receptors. Moreover, our results suggest that EEEG may be appropriate to chronic oral treatment of arterial hypertension.

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Vasorelaxant activities and the underlying pharmacological mechanisms of Gynura procumbens Merr. leaf extracts on rat thoracic aorta

et al. 2017

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Previous studies have investigated the cardiovascular activity of Gynura procumbens Merr. single-solvent extracts. The objective of this study was to evaluate the in vitro vasorelaxant properties and the underlying pharmacological mechanisms of serial extracts and fractions of Gynura procumbens (GP). The leaves of GP were serially extracted with petroleum ether, chloroform, methanol and water using the maceration method. Suspended aortic ring preparations were pre-contracted with phenylephrine (PE 1 µM), followed by cumulative addition of GP extracts (0.25-3 mg/mL). The petroleum ether extract (GPPE) was the most potent among the four extracts. Pre-incubation of endothelium-intact aorta with atropine (1 µM), indomethacin (10 µM), methylene blue (10 µM), propranolol (1 µM) and potassium channel blockers such as TEA (1 µM), glibenclamide (10 µM), 4-aminopyridine (1 µM) and barium chloride (10 mM) had no effect on GPPE-induced vasorelaxation. The vasorelaxant effect of GPPE was partly diminished by pretreatment of aortic rings preparations with L-NAME (10 µM) and even more so in endothelium-denuded aortic rings, indicating a minimal involvement of endothelium-dependent pathway in GPPE-induced vasorelaxation. The calcium-induced vasocontractions were antagonized significantly and concentration-dependently by GPPE in calcium free and high potassium medium. These results illustrate that Ca antagonizing actions of GPPE in rat isolated aorta are comparable to that of verapamil and may be mainly responsible for its vasodilation effect. The antioxidant activity of GPPE supports its vasorelaxant effect by attenuating the production of deleterious free radicals and reactive oxygen species in the vasculature.

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Pharmacological mechanisms involved in the vasodilator effects of extracts from Echinodorus grandiflorus

Cited by 31 publications

References 16 publications

Pharmacological mechanisms underlying the vascular activities of Loranthus ferrugineus Roxb. in rat thoracic aorta

Pharmacological mechanisms underlying the vascular activities of Loranthus ferrugineus Roxb. in rat thoracic aorta

Antihypertensive effects of crude extracts from leaves of Echinodorus grandiflorus

Vasorelaxant activities and the underlying pharmacological mechanisms of Gynura procumbens Merr. leaf extracts on rat thoracic aorta

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