Antidiarrheal activities of isovanillin, iso-acetovanillon and Pycnocycla spinosa Decne ex.Boiss extract in mice

Isovanillin and iso-acetovanillon are two phenolic components isolated from a number of plants including Pycnocycla spinosa. P. spinosa extract has antispasmodic and antidiarrheal activities. However, no comparative study has been done on antidiarrheal action of isovanillin and iso- acetovanillon, so far. The aim of this study was to investigate antidiarrheal action of isovanillin and iso-acetovanillon and their effects on small intestinal transit, for comparison with propantheline. Male mice (25-30 g), fasted over night with free access to water, were treated with test compounds or control (p.o.). Thirty min later castor oil (0.5 ml) was given orally to the animals. In another groups of animals MgSO4 (0.5 ml of 10% solution) was given first and half an hour later the test drugs were administered. Onset and number of wet defecations were recorded for each animal over 3.5 h after treatment with diarrhoea inducing agents. In another groups, intestinal transit of charcoal meal was determined following administration of the compounds. Isovanillin (2 mg/kg & 5 mg/kg), iso-acetovanillon (2 mg/kg & 5 mg/kg) and P. spinosa extract (5 mg/kg) delayed onset of diarrhoea and significantly reduced wet defecation induced by castor oil and MgSO4. They all had antidiarrheal effect similar to propantheline (5 mg/kg). Isovanillin, iso-acetovanillon and P. spinosa extract compared to control groups, significantly reduced small intestinal transit of charcoal meal. This study shows that antidiarrheal effect of P. spinosa extract is at least partially due to presence of two active compounds isovanillin and iso-acetovanillon.