10.22376/ijpbs.2019.10.1.p1-12 Volume 5 Issue 3 2014 (July- September) The current study was undertaken to explore the effect of ethanolic extract (ext.), ethyl acetate (EA) fractions and precipitate fraction (ppt.) of total ethanolic extract of lessThan i greaterThan Andrographis paniculata lessThan /i greaterThan on depression in rats. In the present study, the antidepressant effect of lessThan i greaterThan Andrographis paniculata lessThan /i greaterThan was examined using two behavioral models, the forced swimming test (FST) in rats and the tail suspension test (TST) in rats. In both the screening effects, the immobility time was reduced by 10 and 15 seconds when the ethanolic extract was administered at an acute dose of 50 mg/kg of the body weight compared to the control immobility time of 50 and 60 seconds. In both the tests, the immobility time was reduced by 10 and 15 seconds showing the best activity. The results showed potent activity considering the tested drugs after the standard, imipramine HCl given at 30 mg/kg. Ethanolic extract when administered at an acute dose of 50 mg/kg of body weight (P lessThan 0.01) reduced the immobility time by 10 and 15 seconds as compared to the immobility time of control in both the screening models. Similarly EA reduced latter by 30 and 35 secs. The ppt. fraction showed the best activity, reducing the immobility time by 50 and 60 secs. in both the tests. These results showed that after standard i.e. Imipramine HCl (30 mg/kg), the ppt. fraction is potent amongst all the studied drugs. The present study clearly demonstrated that lessThan i greaterThan Andrographis paniculata lessThan /i greaterThan exerts an antidepressant effect in these two behavioral models. It could be due to presence of labdane diterpenoids and flavonoids. RAVINDRA PATIL, VIMAL SINGH CHAUHAN AND VENKAT R. P. Andrographis paniculata, Labdane diterpenoids, Flavonoids, tail suspension test (TST), forced swimming test (FST). 501-507