Spasmolytic effect of Cuscuta pentagona fruit aqueous extract on rat ileum

ABSTRACT

Cuscuta pentagona [convolvulaceae] has been used in Iran for gastrointestinal disorders. The aim of the present study was to investigate the effect of Cuscuta pentagona fruit aqueous extract [CPE] on rat ileum contractility. The fruit extract was prepared according to the traditional method by boiling the fruits in distilled water. Ileum was dissected from adult male Wistar rat, mounted in an organ bath [10 ml] containing Tyrode solution [37°C, pH 7.4]. I leal contractions were recorded under 1 g initial tension, by an isotonic transducer. In many in-vitro studies, potassium chloride and acetyl cholin induced contractions of rat ileum in the absence or presence of some antagonists had been assessed. In some in vivo studies gastrointestinal transit time in different groups of rats after administration of saline, three doses of fruit extract or atropine, had been measured. Cumulative concentrations of CPE [0.5-8 mg/ml] reduced the ileal contractions induced by KC1 [60 mM] and ACh [1 microM] revealing a dose dependent effect [p<0.0001]. The spasmolytic effect of CPFAE was not reduced after 20-30 minutes of tissue incubation with phentolamine [ImicroM], propranolol [lmicroM] L-NAME 100 microM] and naloxone [1 microM]. In.a Ca[2+]-free Tyrode solution the ileum depolarized by KC1, 120 mM was contracted by addition of cumulative concentration of CaCl[2] [0.225 to 3.6 mM] but CPE [2 and 4 mg/ml] reduced the contractions in a dose dependent manner [p<0.0001]. Furthermore, fruit extract in concentrations of 250, 500 and 750 mg/kg [p.o.] reduced the transit time of charcoal meal in small intestine in a dose dependent manner. Our results suggest that the CPE spasmolytic effect is mediated via calcium channels without involvement of adrenoceptors [alpha and beta] or opioid receptors or any influence on NO synthesis. The results of the present study showed that Cuscuta pentagona fruit aqueous extract reduces rat ileum motility in both in vivo and in vitro studies