Metabolite profile analysis and pharmacokinetic study of emodin, baicalin and geniposide in rats

Abstract

1. Emodin, baicalin and geniposide are the major bioactive components in Da-Huang, Huang-Qin and Zhi-Zi which are herbal medicines widely used in Asian nations.

2. The metabolism of the three compounds was found to undergo hydroxylation, decarboxylation, dehydration, methylation, hydrolysis, hydrogenation, dihydrogenation, sulfation, glucosidation and/or glucuronidation. A total of 63 metabolites were detected in urine, plasma and bile of rats given a mixture of the three compounds.

3. Pharmacokinetic properties of the three compounds were determined in rats given the extracts of Da-Huang, Huang-Qin and Zhi-Zi. The pharmacokinetic parameters for emodin, baicalin and geniposide were found to be 0.13 ± 0.11, 0.25 ± 0.12 and 0.40 ± 0.09 h (T_max); 21 ± 9, 1515 ± 254 and 482 ± 50 ng/mL (C_max); 8.6 ± 5.5, 18.3 ± 2.8 and 22.1 ± 17.2 h (t_1/2); 29 ± 20, 16886 ± 3734 and 2936 ± 551 ng/mLċh (AUC_(0–t)); and 37 ± 20, 22624 ± 6295 and 3582 ± 820 ng/mLċh (AUC_(0–∞)).

4. The metabolism and pharmacokinetic studies facilitate appropriate employment of Da-Huang, Huang-Qin and Zhi-Zi in clinic.

Keywords:

• Metabolic fate of multiple components
• metabolic pathways
• metabolite identification
• pharmacokinetics
• UPLC/Q-TOF-MS
• Zhi-Su-Ning

Declaration of interest

Authors declare no competing interest.

This work was supported in part by Grant 81373471 and 81430086 of the National Natural Science Foundation of China.