Relaxant effects of the essential oil of Ocimum gratissimum on isolated ileum of the guinea pig.

The effects of the essential oil of Ocimum gratissimum L. (Labiatae) (EOOG) on guinea pig ileum were studied. EOOG (0.1-1000 microg/ml) reversibly and concentration-dependently relaxed the basal tone of the ileum and reversed the tonic contractions induced by 60 mM KCl and 10 microM acetylcholine, with IC(50) values of 23.8+/-5.2, 18.6+/-4.0 and 70.0+/-4.6 microg/ml, respectively. Our results show that EOOG exerts relaxant effects on intestinal smooth muscle, consistent with the popular use of the plant to treat gastrointestinal disorders.