Role of thymol in inhibition of acetylcholine induced contraction of isolated rat’s ileum

Introduction: Thymol has negative ionotropic effect on heart and has direct effect on calcium release from sarcoplasmic reticulum. Some of the herbal plants just like carum copticum consist of thymol. The postganglionic neurons of the gastrointestinal parasympathetic system are located mainly in the myenteric and submucosal plexuses. Stimulation of these parasympathetic nerves causes general increase in activity of the entire enteric nervous system. This in turn enhances activity of most gastrointestinal functions. Therefore the present study has been designed to find out the anti spasmodic effects of thymol on rat’s ileum smooth muscle. Methods: In this study rat’s ileum contraction was recorded through an isolated tissue chamber in an organ bath by using isotonic transducer and oscillographic device and in each experiment the effective concentration of Carum Copticum and thyme essential oil (0.002, 0.005 and 0.01) on acetylcholine induced contraction in isolated rat’s ileum was evaluated and compared with thymol (10 -3, 10 -4 and 10 -5) effects. Results: Our result show that acetylcholine in the presence of thymol with concentration of 10-4 & 10-5 M cause smooth muscle contraction while its concentration of 10-3 M inhibited smooth muscle contraction which is significant as compared with control group (P<0.05). Conclusion: this study showed that thymol inhibited acetylcholine induced contraction in isolated rat’s ileum and due to the high concentration in some of medicinal plant its anti spasmodic effects may be due to the presence of thymol on that.