Endothelium-Independent Vasorelaxant Effects of Hydroalcoholic Extract fromNigella sativaSeed in Rat Aorta: The Roles of Ca²⁺and K⁺Channels

Abstract

Objective. The aim of this study was to elucidate the mechanism(s) responsible for the vasorelaxant effect of Nigella sativa (N. sativa). Methods. The activity of different concentrations of N. sativa extract was evaluated on contractile responses of isolated aorta to KCl and phenylephrine (PE). Results. The extract (2–14 mg/mL) induced a concentration dependent relaxation both in endothelium-intact and endothelium-denuded aortic rings precontracted by PE (10−6 M) and KCl (6 × 10−2 M). Extract reduced PE- and KCl-induced contractions in presence of cumulative concentrations of calcium (10−5–10−2 M) significantly. L-NAME and indomethacin had no effect on vasorelaxation effect of extract in PE-induced contraction. Diltiazem and heparin reduced significantly this vasorelaxation at a concentration of 14 mg/mL of extract; however, N. sativa-induced relaxation was not affected by ruthenium red. Tetraethylammonium chloride reduced the extract-induced relaxation in concentrations of 2–6 mg/mL of extract significantly but glibenclamide reduced this relaxative effect in all concentrations of extract. Conclusions. The inhibitory effect of N. sativa seed extract on the contraction induced by PE and KCl was endothelium-independent. This relaxation was mediated mainly through the inhibition of Ca2+ and KATP channels and also intracellular calcium release.

The vasorelaxant effect of Canarium odontophyllum Miq. (Dabai) extract in rat thoracic aorta

“…Inositol triphosphate then stimulates the release of Ca 2+ from SR after activation of IP 3 receptor [27] leading to vascular smooth muscle contraction. This result contradicts with the study on the seed extract of Nigella sativa that its hypotensive effect occurred via inhibitory action on the release of intracellular Ca 2+ stores from SR [28].…”

The use of medicinal herbs in gynecological and pregnancy-related disorders by Jordanian women: a review of folkloric practice vs. evidence-based pharmacology

“…Black seed oil is promoted as male fertility agent (Ghazeeri et al 2012) and could ameliorate and reverse the nicotine induced reduction in sperm motility and morphology and Antidiabetic, hypotensive, antiobesity, antiinflammatory, antioxidative, cytotoxic-proapoptotic, hypolipidemic, nephroprotective, antiepileptic with antimalarial and antifungal capacities (Develi et al 2014;Razavi & Hosseinzadeh 2014;Afifi & Kasabri 2014;Tembhurne et al 2014). Vasorelaxant in rat aorta (Niazmand et al 2014) and antidepressant (Perveen et al 2013). …”

Teucrium polium-induced vasorelaxation mediated by endothelium-dependent and endothelium-independent mechanisms in isolated rat thoracic aorta

“…Vascular isometric tension was determined by organ bath technique as described previously. [ 32 ] In brief, after anesthesia with ketamin (50 mg/kg, i.p), animals were decapitated by guillotine; descending thoracic aorta was rapidly dissected out and immersed in chilled Krebs solution composed of the following (in mM): NaCl 118.5, potassium chloride (KCl) 4.74, MgSO 4 1.18, NaHCO 3 24.9, CaCl 2 2.5, glucose 10, and bubbled with carbogenic mix (95% O 2 , 5% CO 2 , pH = 7.4). The aorta was removed free of the perivascular tissue and cut into ring segments 5 mm in length and care was taken to avoid any damage to the endothelium.…”