Receptor mechanisms of Thymoquinone-induced hypotension in normotensive rats
Nigella sativa seeds “black cumin” have been widely used in traditional medicine for diseases treatment including hypertension. Thymoquinone (TQ) is one of the major active constituents in its volatile oil. The objective of the current study was to confirm the blood pressure lowering effect of TQ, a...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI
2014
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| Subjects: | |
| Online Access: | http://irep.iium.edu.my/38818/ http://irep.iium.edu.my/38818/ http://irep.iium.edu.my/38818/ http://irep.iium.edu.my/38818/1/Azzubaidi.pdf |
| Summary: | Nigella sativa seeds “black cumin” have been widely used in traditional medicine for diseases treatment including hypertension. Thymoquinone (TQ) is one of the major active constituents in its volatile oil. The objective of the current study was to confirm the blood pressure lowering effect of TQ, and to investigate its mechanism through muscarinic and β adrenergic receptors. Mean arterial blood
pressure (MAP) was recorded using the non-invasive blood pressure tail cuff technique. Dose-response relationship was obtained after using 3 TQ doses (2.5, 5 and 10 mg/kg) intraperitoneally to 3 different groups (n = 5) of adult male Sprague Dawley rats under pentobarbital anesthesia. MAP was then measured for other 2 animal groups pretreated either with atropine (P-at) or propranolol (P-pro) followed
by 10 mg/kg TQ. TQ produced a dose-dependent blood pressure lowering effect, where 2.5 mg/kg reduced MAP by 8 ± 1 mmHg, whereas 5 and 10 mg/kg of TQ treatment decreased MAP by 12 ± 3 and 29 ± 3 mmHg, respectively. TQ-induced MAP reduction was significantly less in P-at than non-pretreated group.
Conversely, TQ-induced MAP reduction in P-pro did not demonstrate significant difference from the non-pretreated
group.
This study confirms the dose-related hypotensive effect of TQ and provides an evidence for the traditional use of
Nigella sativa for treatment of hypertension. The mechanism of TQ-induced hypotensioninvolves at least in part activation of vascular muscarinic receptors, but not β-adrenergic receptors. |
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