antispasmodic effect of physalis alkekengi fruit extract

background: studies have shown that physalis alkekengi reduces implantation and induces antifertility in rat. in iranian traditional medicine it is believed that this plant has abortifacient and antifertility activities. objective: the goal of this study was to evaluate the effect of physalis alkekengi ripe fruit hydroalcoholic extract (pfe) on uterine contractility and its possible mechanism(s). materials and methods: extraction of physalis alkekengi fruit was carried out by maceration method (70% alcohol). uterus was dissected out from adult non-pregnant rat (wistar) and contracted by kcl (60mm) or oxytocin (10mu/ml) in an organ bath containing de jalon solution and the effect of pfe on the uterine contractions was investigated. furthermore, the role of α- and β-adrenoceptors, opioid receptors, nitric oxide and cyclic guanosine monophosphate synthesis inhibitors on the extract effects were evaluated. results: kcl- and oxytocin-induced uterine contractions were inhibited (p<0.001) by the cumulative concentrations of the extract in a concentration dependent manner. incubation of uterus with propranolol (1μm) and l-name (100μm) attenuated the pfe antispasmodic effect (p<0.05). but the pfe effect was unaffected by phentolamine (1μm), naloxone (1μm) or methylene blue (10μm). in ca2+-free with high potassium (60mm) de jalon solution, cumulative concentrations of cacl2 (0.1-0.5mm) induced uterine contraction concentration-dependently (p<0.001). uterus incubation (5min) with pfe (0.25-1.75mg/ml) attenuated the cacl2–induced contractions (p<0.05). conclusion: it seems that the extract induced antispasmodic effect mainly via calcium influx blockade and partially through blocking β-adrenoceptors and nitric oxide (no) synthesis. however, neither α-adrenoceptors nor opioid receptors or cgmp synthesis were involved.