THYMOQUINONE RELAXES INTESTINAL SMOOTH MUSCLES THROUGH MUSCARINIC RECEPTOR AND Ca-CHANNEL BLOCKADE

Background: Functional bowel disorders are common clinical disorders with poorly understood pathophysiology and no gold standard treatment yet. Nigella sativa and its active component thymoquinone are known for their different beneficial medicinal properties and are being widely researched nowadays. Their effect on intestinal motility may prove beneficial in treatment of functional bowel disorders. Objectives: To study the effect of Thymoquinone on intestinal motility. Materials & Methods: Rabbits of 1-1.5 kg were sacrificed and effect of thymoquinone was studied on spontaneous contractions in isolated jejunal pieces. Isolated pieces of ileum were used to study contractions induced by carbachol and KCl both alone and in presence of three increasing concentrations of thymoquinone. Results: Thymoquinone depressed both spontaneous jejunal contractions and contractions induced by carbachol and KCl. The effect was concentration dependant for low and moderate concentrations of thymoquinone on carbachol induced contractions and for moderate and high concentrations of thymoquinone on KCl induced contractions. Conclusion: Thymoquinone depresses intestinal motility and the possible mechanism may be through muscarinic receptor and Ca-channel blockade. Further studies are needed to establish dose and safety profile.