title: The effect of cinnamon extract on isolated rat uterine strips.
abstract: Cinnamon is a spice used by some populations as a traditional remedy to control blood pressure and thus hypertension. Cinnamon extract decreases contractility in some smooth muscles, but its effect on uterine smooth muscle is unknown. The aim of this study was to determine the physiological and pharmacological effects of cinnamon extract (CE) on the contractions of isolated rat uterine strips and to investigate its possible mechanism of action. Isolated longitudinal uterine strips were dissected from non-pregnant rats, mounted vertically in an organ bath chamber, and exposed to different concentrations of CE (10-20mg/mL). The effect of CE was investigated in the presence of each of the following solutions: 60mM KCl, 5nM oxytocin, and 1μM Bay K8644. CE significantly decreased the force of uterine contraction in a concentration-dependent manner and significantly attenuated the uterine contractions elicited by KCl and oxytocin. In addition, CE significantly decreased the contractile force elicited when L-type Ca(2+) channels were activated by Bay K8644. CE's major mechanism may be inhibition of L-type Ca(2+) channels, which limits calcium influx. These data demonstrate that CE can be a potent tocolytic that can decrease uterine activity regardless of how the force was produced, even when the uterus was stimulated by agonists. As a result, cinnamon may be used to alleviate menstrual pain associated with dysmenorrhoea or prevent unwanted uterine activity in early pregnancy.
authors.affiliation: Department of Physiology, College of Medicine, King Saud University and King Khalid University Hospital, P.O Box 2925, Riyadh 11461, Saudi Arabia. Electronic address: mfalotaibi@ksu.edu.sa.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Alotaibi
mesh_terms: D000818:Animals; D020746:Calcium Channels, L-Type / Q000378:metabolism; D002935:Cinnamomum zeylanicum / Q000737:chemistry*; D005260:Female; D009119:Muscle Contraction / Q000187:drug effects; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D014599:Uterus / Q000187:drug effects*
chemical_list: D020746:Calcium Channels, L-Type; D010936:Plant Extracts
keywords: Cinnamon; Contraction; L-type Ca(2+) channel; Smooth muscle; Uterus