Oral Phyto-thymol ameliorates the stress induced IBS symptoms

Physical stressors play a crucial role in the progression of irritable bowel syndrome (IBS). Here we report a heterogeneous physical stress induced IBS rat model which shows depression and subsequent modulation of IBS by oral treatment of thymol. Oral administration of Thymol reduces the stress induced IBS significantly altering the stress induced gastrointestinal hypermotility, prolonged the whole gut transit time, and increased abdominal withdrawal reflex suggesting gastrointestinal hypermotility and visceral discomfort caused the onset of depression. Immunohistochemical analysis in small intestine and colon of rats shows the decreased 5-HT_3AR expression level while thymol treatment normalized the 5-HT_3AR expression in the stressed rats. Molecular docking studies showed that thymol competes with endogenous serotonin and an antagonist, Tropisetron and all have similar binding energies to 5-HT_3AR. Molecular dynamics simulations revealed that thymol and tropisetron might have similar effects on 5-HT_3AR. Our study suggest that thymol improves IBS symptoms through 5-HT_3AR, could be useful for the treatment of IBS.