Pharmacokinetics of Gambogic Acid in Rats

AIM:To study the pharmacokinetics of gambogic acid in rats.METHODS:Following i.v. administration,HPLC was used to determine gambogic acid concentration in the rat plasma,tissues,bile,feces and urine.RESULTS:Mean elimination half life time(t_(1/2)) of gambogic acid in rats plasma was about 15 min.The relationship between dose and AUC showed excellent linearity,suggesting that there was linear disposition of gambogic acid in rats in the dose range.Following i.v. administration to rat,gambogic acid mainly distributed in the organs such as liver,lung,spleen,kidney,stomach,intestine and heart.Gambogic acid was mainly excreted through bile and the percentage of the corresponding cumulative excretion was found to be about 36.5% within 16 h.In addition,only traces appeared in the feces,and no gambogic acid was detected in the urine.There were four metabolites isolated from the rat bile.Moreover,the mean plasma protein bound fraction of gambogic acid was (31.1%.)CONCLUSION:Gambogic acid was rapidly eliminated from the rat plasma, extensively distributed and metabolized in rats after i.v. administration.Following i.v. administration,gambogic acid was mainly excreted in the bile in both parent and metabolite forms.