Relaxant effect of Lagenaria breviflora Roberty fruit pulp and seeds on isolated rabbit ileum
Lagenaria breviflora roberty is used in West Africa as traditional remedy for treatment of gastrointestinal disorders, particularly diarrhoea. This study was aimed at assessing the effect of the pulp and seed extract of L. breviflora on the contractile activity of isolated rabbit ileum. Rabbits of both sexes were used for the study and a rabbit was sacrificed for each experiment. The ileum was located and taken out into a petri dish containing Tyrode solution constantly aerated by an air pump. The organ was cut into strips of about 2cm long and mounted in an organ bath. The contractile responses were recorded on a kymograph. The maximum response (Emax), concentration producing 50% of the response (EC50) and affinity (pA2) were determined from repeated experiments conducted. Values were expressed as mean±SEM and significant differences were determined using one way ANOVA (p<0.05). The extracts caused a dose-dependent relaxation of the ileum and the relaxant effect was antagonized by prazosin and phenoxybenzamine (ß-adrenergic antagonists) with a right shift in concentration response curves (CRCs) obtained. Propranolol (ß adrenergic antagonist) caused a left shift in the CRCs obtained. Emax and EC50 for the extracts reduced, while pA2 increased. The extracts produced á-adrenergic receptor-mediated gastrointestinal smooth muscle relaxation which explains the rationale for the use of L. breviflora fruit for treatment of diarrhoea.
Keywords: Adrenergic, Antagonists, Breviflora, Contractility, Lagenaria.