RESUMO
Hydroalcoholic extract of Pycnocycla spinosa Decne. exBoiss. var. spinosa has in vitro spasmolytic action, and at oral dose of 250 micro g/kg inhibits castor oil induced diarrhoea in mice. In this investigation, effects of P. spinosa var. spinosa extract in comparison with nifedipine on blood pressure and heart rate in animal model was studied. Injection of three bolus doses of P. spinosa var. spinosa extract [100 micro g/kg, 500 micro g/kg and 1mg/kg] into the jugular vein, temporary reduced blood pressure and heart rate. However, soon after completion of extract administration blood pressure and heart rate returned to normal. Nifedipine on the other hand caused a sustained reduction in blood pressure and decreased heart rate compared with the control group. From this study it was concluded that P. spinosa var. spinosa extract at antidiarrhoeal dose has no significant effect on blood pressure and heart rate