Objective: It was explored in the article that the compatibility connotation of Aconiti Radix and Pinelliae Rhizoma (PR) after the different processed products of PR was added to Wutoutang (WTT) from cytochrome P450 enzyme system (CYP) 3A1/2 medating metabolic herb-herbs interaction in rats. Method: The change of CYP3A enzymatic activity was detected by incubation in vitro and probe method in vivo.The expression of protein and mRNA was determined with Western blot and the fluorescence quantitative polymerase chain reaction (PCR) technology. Result: By comparing with WTT adding unprocessed Pinelliae Rhizoma (UPR)

the production rate of 6β-hydroxy-testosterone (6β-OH-Tes) did not change and the expression of CYP3A protein were increased (P<0.01

P<0.05) in WTT adding Pinelliae Rhizoma Praeparatum (PRP)

the mRNA expression of CYP3A1 was decreased (P<0.01) only in 0.60 g · kg-1 group of WTT adding PRP;the production rate of 6β-OH-Tes was very dramatically decreased (P<0.01) in 1.20 g · kg-1 group of WTT adding Pinelliae Rhizoma Praeparatum cum Zingibere et Alumine (PRPZA)

the expression of CYP3A protein was increased (P<0.05) only in 0.60 g · kg-1 group of WTT adding PRPZA

the mRNA expression of CYP3A1 were markedly decreased (P<0.01) in 0.60

1.20 g · kg-1 groups of WTT adding PRPZA;the ratios between AUC0-t of 6'-hydroxy-buspirone (6'-OH-BP) and AUC0-t of buspirone (BP)

AUC0-t of 1-(2-pyrimidinyl)-piperazine (1-PP) and AUC0-t of BP did not change in WTT adding PRP/PRPZA by comparing with WTT adding UPR. Conclusion: Different processed products of PR can enhance the inhibition of WTT on CYP3A activity in various degree

which may slower the metabolism of diester diterpenoid alkaloids(such as aconitine) in WTT

and then lead to increase the toxicity or the pharmacological action of WTT.