EFFECTS OF BLACK TEA EXTRACT AND ITS THEARUBIGINS ON WHOLE GUT TRANSIT TIME IN MICE: INVOLVEMENT OF 5-HT3 RECEPTORS

Tea is the most popular beverage in the world. In the recent decades therapeutic effects of various type of tea drinking has been revealed in many studies. The purpose of this study was to evaluate the effects of the black tea extract (BTE) and its major polyphenolic pigments thearubigins (TRs) on whole gut transit time in mice by use of carmine marker. BTE of Iranian tea was prepared and its polyphenolic pigment TRs extracted by Liquid- liquid partition method. BTE (1.5%, 3%, 4.5%, 6%, and 10%) and extracted TRs (30 mg/kg, 40mg/kg, 50mg/kg, 60 mg/kg, 70mg/kg, and 100mg/kg) were gavaged to the fasted mice to measuring the whole gut transit time. Results showed BTE (3%, 4.5%, 6 %,) and TRs (40mg/kg, 50mg/kg, 60 mg/kg, 70mg/kg) significantly decreased the whole gut transit time dose dependant manner. For determination of serotonergic system involvement as a major neurotransmitter system in transit time alteration caused by BTE and TRs, ondansetron (3mg/kg, i.p) was used.Acquired data showed that 5-HT³ antagonist blocked accelerating effects of BTE and TRs. Based on the results BTE and TRs could be regarded as gut accelerator movement dose dependant manner. Moreover, it was concluded that these effects at least partially involved with serotonergic system via   5-HT₃ receptors.