Akram Ahangarpour - Department of Physiology, School of Medicine, Physiology and Diabetes Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
Ali Akbar Oroojan - Department of Physiology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
Ashraf Amirzargar - Department of Physiology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
Maryam Ghanavati - Department of Nursing, School of Nursing and Midwifery, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.

Background: Citrus aurantium is a small citrus tree, with scented white flowers. The C. aurantium is used in Asian herbal medicine primarily to treat digestive problems.Objective: The goal of this study is to investigate the effect of C. aurantium flower's aqueous extract on uterine contraction in presence of some known uterus stimulants.Materials and Methods: In experimental study 30 virgin Wistar rats 200-300gr were obtained. After laparatomy, a piece of Uterus was dissected out and mounted in an organ bath (10ml) containing De Jalon (29°C) and contracted by KCl (60mM), oxytocin (10mU/ml) and barium chloride (4mM) then the effect of C. aurantium flower's aqueous extract (1-8 mg/ml) on the uterine contractions was investigated. Uterus was separately incubated with propranolol (1M), naloxone (1M) and the role of β-adrenoceptors, opioid receptors were evaluated.Results: Cumulative concentrations of the extract (1-8 mg/ml) decreased KCl, oxytocin and barium chloride induced uterine contractions, dose-dependently (p<0.001). C. aurantium flower's aqueous extract was unaffected on incubation the tissue with propranolol and naloxone.Conclusion: It seems that the extract induced antispasmodic effect mainly via calcium influx blockade. However, neither β-adrenoceptors nor opioid receptors were involved. Since the extract has antispasmodic effect on uterus contraction therefore we can suggest that more study will be necessary to relief dysmenorrheal.

Citrus aurantium, Propranolol, Naloxone, Antispasmodic, Uterus, Rat