Objective:To establish a basis for Angelica Sinensis Radix (ASR) as a dietary supplement for colorectal cancer chemoprevention,the effect of co-existent components in supercritical fluid extract (SFE) of ASR on the pharmacokinetics of Z-ligustilide after oral administration was investigated in vitro and in vivo.Methods:Incubation in gastrointestinal contents and incubation in rat liver tissue homogenates post-mitochondrial supatant (PMS) experiments were used to study changes in the levels of Z-ligustilide in vitro.Results:Within 4 hours,the level of Z-ligustilide in SFE declined at a slower rate than in its pure form.Clearance of Z-ligustilide after administration in its pure form was significantly slower than that of SFE of ASR (CL,0.96 ± 0.16 mL·min/kg versus 1.24 ± 0.21 mL·min/kg P ＜ 0.05;AUC,243.37 ± 16.84 versus 176.69 ± 12.59 mg·min/L).Conclusion:These phenomena may be attributed to the interactions between the co-existent components in SFE of ASR and Z-ligustilide enhancing the stability of Z-ligustilide.These results suggest that the bioavailability of Z-ligustiltide in SFE of ASR is improved.However,stabilization of plasma concentration was not sustained,so that the efficacy of active components could not be maintained.Thus,further processing of SFE of ASR is required.