Pueraria candollei (Leguminosae) has long been used as a traditional medicine for rejuvenation, and the major constituents in the tuberous root are isoflavonoids. The effects of the root cultures of P. candollei (r-PC) on cytochrome P450 enzymes in mouse liver and antioxidant activity in mouse brain including gross anatomy were examined. r-PC significantly enlarged the uterus length while no change in weight was noted. The total P450 content was not significantly altered by either estradiol benzoate (ES) or r-PC. Benzyloxyresorufin O-dealkylase activity was significantly increased by r-PC, comparable to the increase induced by ES. Correspondingly, r-PC demonstrated a tendency to upregulate CYP2B9 mRNA expression. Furthermore, assessment of lipid peroxidation in mouse brain using the thiobarbituric acid assay demonstrated that r-PC remarkably decreased the level of malondealdehyde formation. These observations suggest r-PC as a potential alternative to ES with the extrabenefit of its antioxidant activity.