Calcium channel blockade as a target for the cardiovascular effects induced by the 8 (17), 12E, 14-labdatrien-18-oic acid (labdane-302)

Oliveira, Aldeídia Pereira de; Furtado, Fabíola Fialho; Silva, Marcelo Sobral da; Tavares, Josean Fechine; Mafra, Roberta Amaral; Araújo, Demétrius Antônio Machado de; Cruz, Jáder Santos; Medeiros, Isac A.

doi:10.1016/j.vph.2006.01.009

Cited by 35 publications

(35 citation statements)

References 24 publications

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“…It is possible that such enhancement occurred but was impaired by the blunted vasorelaxation of labd-8 in preparations from SHRs. It is noteworthy that the maximal percent decrease in MAP elicited by labd-8 in WKY (around 31%) was greater than that evoked by 8(17),12E,14-labdatrien-18-oic acid (around 18%) (de Oliveira et al, 2006) but seems minor than that recorded for labda-15-oic acid (around 43%) (Simplicio et al, 2014) in normotensive rats. Moreover, the maximal hypotension of labd-8 occurred at a dose (10 mg/ kg) three-fold higher than that (3 mg/kg) of labda-15-oic acid (Simplicio et al, 2014) but was two-fold lower than that (20 mg/kg) observed for 8(17),12E,14-labdatrien-18-oic (de Oliveira et al, 2006).…”

Section: Discussionmentioning

confidence: 68%

“…For instance, marrubenol was shown to induce vasorelaxant effects through blockade of L-type calcium channels (El-Bardai et al, 2003). The diterpene 8 (17),12E,14-labdatrien-18-oic acid decreased blood pressure in conscious normotensive rats, an effect mainly attributed to reduced peripheral vascular resistance through activation of the NO-pathway and blockage of L-type calcium channels (de Oliveira et al, 2006). Recently, it was shown that labdane ent-3-acetoxy-labda-8(17),13-dien-15-oic acid induced hypotension and vascular relaxation through the activation of the endothelial NO-cGMP pathway, the opening of potassium channels, and the alteration of calcium mobilization (Simplicio et al, 2014).…”

Section: Introductionmentioning

confidence: 99%

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Cardiovascular effects of a labdenic diterpene isolated fromMoldenhawera nutansin conscious, spontaneously hypertensive rats

Correia

Siqueira

Interaminense

et al. 2014

Pharmaceutical Biology

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Context: The labdenic diterpene labd-8(17)-en-15-oic acid (labd-8) isolated from a methanolic extract of Moldenhawera nutans Queiroz & Alkin (Leguminosae) has hypotensive and tachycardiac properties in normotensive rats. A part of the hypotensive effect was due to a reduction in the sympathetic nerve drive to vessels, an event admittedly enhanced in spontaneously hypertensive rats (SHRs). Objectives: We assessed whether the cardiovascular effects induced by labd-8 could be enhanced in SHRs. Materials and methods: For in vivo experiments, arterial and venous catheters were implanted under anesthesia for blood pressure recording and drug administration, respectively. For in vitro experiments, thoracic aorta rings were suspended in organ baths containing warm (37 C) perfusion medium that was continuously bubbled with carbogen. Results: Intravenous injection of labd-8 (1, 3, 5, and 10 mg/kg) induced similar dose-dependent hypotension and tachycardia in both SHRs and Wistar-Kyoto rats (WKY). In SHRs, only the tachycardia response to labd-8 was significantly reduced by pretreatment with methylatropine or propranolol. However, both cardiovascular effects of labd-8 were reduced by hexamethonium while remained unchanged by L-NAME. In isolated aortic preparations from SHRs, labd-8 (1-1000 mg/mL) relaxed potassium-induced contractions with an IC 50 (geometric mean [95% confidence interval]) value (536.5 [441.0-631.9] mg/mL) significantly greater than that (157.6 [99.1-250.5] mg/mL) obtained in preparations from WKY rats. Conclusion: In SHRs, the hypotension induced by labd-8 is associated with a reflex tachycardia and seems mediated partly through withdrawal of sympathetic vasomotor tone and partly through an active vasorelaxation. Its magnitude was not enhanced when compared with WKY rats likely because of impaired vasorelaxant effects of labd-8 in preparations from SHRs.

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Section: Discussionmentioning

confidence: 68%

Section: Introductionmentioning

confidence: 99%

Cardiovascular effects of a labdenic diterpene isolated fromMoldenhawera nutansin conscious, spontaneously hypertensive rats

Correia

Siqueira

Interaminense

et al. 2014

Pharmaceutical Biology

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“…In the present study, glibenclamide did not produce any significant effect on concentration-response curves of KV, suggesting that KATP channels are not involved in the vasorelaxation induced by the biflavonoid. Similarly, neither apamin, BaCl2 nor ouabain, blockers of SKca, KIR channels and Na + -K + ATPase, respectively (Cortes et al, 2001;Tirapelli et al, 2004;Oliveira et al, 2006) affected the concentration-response curves of KV, hence these channels and the ATPase are not involved in the vasorelaxant effects of KV. TEA and ChTX, at these concentrations are nonselective blockers of large and intermediate conductance Ca 2+ -activated K + channels (BKCa).…”

Section: Discussionmentioning

confidence: 99%

“…The concentration used for each blocker/inhibitor of K + channels is sufficient to antagonize selectively those channels in arterial smooth muscle (Nelson and Quayle, 1995;Lagaud et al, 1999;Cortes et al, 2001;Oliveira et al, 2006). After stabilization of the tonic contraction induced by PHE, increasing cumulative concentrations of KV (1, 10, 30, 100, 300, 500 and 1,000 µg/ml) were added to the organ bath.…”

Section: Investigation Of the Role Of K + Channels In The Kv-induced mentioning

confidence: 99%

Endothelium-independent vasodilation induced by kolaviron, a biflavonoid complex from Garcinia kola seeds, in rat superior mesenteric arteries

Adaramoye¹,

Medeiros²

2009

J Smooth Muscle Res

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Previous studies have established the hepatoprotective, gastroprotective, hypolipidemic and hypoglycemic effects of kolaviron (KV), a biflavonoid complex from Garcinia kola seeds. In this study, we investigated the mechanisms involved in the vasorelaxant effects of KV in isolated superior mesenteric arteries from normotensive rats. KV (1, 10, 30, 100, 300, 500 and 1,000 µg/ml) concentration-dependently inhibited the contractions induced by phenylephrine (PHE) (10 µM) and KCl (80 mM) in both endothelium-intact (Emax = 58.3 ± 1.7% and 51.4 ± 1.3%, respectively) and -denuded rings (Emax = 59.3 ± 5.5% and 64.3 ± 2.4%, respectively). Furthermore, KV reduced CaCl2-induced contraction in Ca 2+ -free medium containing KCl 60 mM, thus acting as a Ca 2+ -antagonist. In addition, KV inhibited the transient contraction by PHE in Ca 2+ -free medium containing EGTA, suggesting a possible action on the release of intracellular Ca 2+ via the inositol-1,4,5-triphosphate (IP3) pathway.KV is not a specific α-adrenoceptor blocker, since it also caused a concentration-dependent inhibition of contractile responses to KCl, suggesting that KV also blocks the L-type Ca 2+ -channel. As a Ca 2+ antagonist, KV (100 µg/ml) potentiates the relaxant effects of nifedipine in denuded rings (Emax = 97.6 ± 1.2%; control = 75.1 ± 3.0%, P<0.05). Also, the vasorelaxation induced by KV was significantly inhibited after pre-treatment of the denuded rings with 4-aminopyridine (4-AP) 1 mM, a selective blocker of voltage-dependent K + (Kv) channels and,

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“…O diterpeno ácido 8 (17), 12E, 14-labdatrien-18-óico (29) foi isolado do extrato etanólico do caule da xylopia langsdorffiana (Oliveira et al, 2006). Esse tipo diterpeno labdano tem mostrando claramente seu potencial como "lead compound" no desenvolvimento de novos fármacos (Singh et al, 1999).…”

Section: Xylopia Langsdorffiana a St Hil And Tulunclassified

Plantas do Gênero Xylopia: Composição Química e Potencial Farmacológico

Silva

Reis

Moura

et al. 2015

Rev. bras. plantas med.

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RESUMO:A família Annonaceae possui representantes de grande interesse medicinal e o gênero Xylopia é um dos que merecem destaque. Composta por aproximadamente 160 espécies distribuídas na América do Sul, América central, África e Ásia, as espécies desse gênero podem ser arbustivas ou arbóreas. No Brasil são encontradas nas regiões Norte, Nordeste, CentroOeste e Centro Sul. Este gênero produz uma variedade de metabólitos incluindo alcalóides, amidas, lignóides, acetogeninas e terpenóides e têm sido investigados como fonte potencial de acetogeninas, compostos esses que apresentam uma ampla variedade de propriedades biológicas com destaque para: citotóxica, antitumoral, antiparasitária, antimicrobial, inseticida e antimalarial. Neste estudo, efetuou-se uma revisão das principais espécies de Xylopia encontradas no Brasil, já estudadas e descritas na literatura, abordando os aspectos químico-farmacológicos, destacando os constituintes químicos isolados bem como a ação farmacológica evidenciada. Palavras-chave:Xylopia, medicina popular, composição química, efeito farmacológico. ABSTRACT: Plants of the Xylopia Genus: Chemical Composition and PharmacologicalPotential. The family Annonaceae has representatives of great medical interest, and the Xylopia species deserves attention. The Xylopia genus is composed by approximately 160 species, with geographic distribution in tropical and subtropical regions of America, Africa and Asia. This genus can present shrubs or trees. In Brazil, they can be found at the North, North-west, Central-West and Central-South Regions. The phytochemical investigations resulted mainly in the isolation of alkaloids, diterpenos, quinolines and acetogenins, with the latter presenting very interesting biological properties such as the cytotoxic, antiprotozoal and the insecticide activities.This study aimed to review the botanical, chemical and pharmacological aspects of the Xylopia genus found in Brazil, highlighting the chemical components, as the well-known pharmacological effect .

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Calcium channel blockade as a target for the cardiovascular effects induced by the 8 (17), 12E, 14-labdatrien-18-oic acid (labdane-302)

Cited by 35 publications

References 24 publications

Cardiovascular effects of a labdenic diterpene isolated fromMoldenhawera nutansin conscious, spontaneously hypertensive rats

Cardiovascular effects of a labdenic diterpene isolated fromMoldenhawera nutansin conscious, spontaneously hypertensive rats

Endothelium-independent vasodilation induced by kolaviron, a biflavonoid complex from Garcinia kola seeds, in rat superior mesenteric arteries

Plantas do Gênero Xylopia: Composição Química e Potencial Farmacológico

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