ABSTRACT
Present study aims to elucidate the effects of chronic administration of St. John's Wort [SJW] [500mg/kg] on brain tryptophan [TRP] metabolites and indoleamine 2-3 dioxygenase [IDO] activity in alcohol treated mice. Locally bred Albino BALB/c mice, weighing 20-25g were divided into three groups [untreated controls, Alcohol, Alcohol +Drug] having 6 mice in each. Freshly prepared ethanol solution was administered in drinking water in the proportion of 5% for three days or 8% for 3 weeks to two groups. After 3 weeks drug group was treated with SJW [dissolved in ethanol: saline 1:3 v/v] at a dose of 500mg/kg was administered orally for 1 week. During treatment alcohol intake was monitored .In present finding chronic administration of SJW significantly reduced ethanol intake by 78.6% [P<0.001] in mice. Data analyzed by student's t-test indicates that SJW remarkably reduce kynurenine [KYN] by 60.9% [P<0.001] and KYN/TRP ratio [IDO] activity] by 70.9% [P<0.001] in brain. Low serotonin level promotes alcohol intake. Present results suggest that SJW decreases alcohol intake by inhibiting IDO thereby shifting TRP catabolism towards serotonin synthesis