Comparative pharmacokinetics of chlorogenic acid in beagles after oral administrations of single compound, the extracts of Lonicera japanica, and the mixture of chlorogenic acid, baicalin, and Forsythia suspense.

CONTEXT: Chlorogenic acid (ChA) is the major compound in Shuang-Huang-Lian (SHL), which is mainly composed of ChA, baicalin, and Forsythia suspense Thunb Vahl.

OBJECTIVE: The effects of co-existing compounds in SHL and Lonicera japanica Thunb on the absorption of ChA was investigated.

MATERIALS AND METHODS: According to 3 × 3 Latin-square test, ChA alone, the extracts of Lonicera japanica, or the mixture of ChA, baicalin and Forsythia suspense (ChA effective doses is 60 mg/kg) was separately given to six beagles for seven days. The oral pharmacokinetic parameters of ChA in plasma, urine and faeces were quantified by HPLC/UV and analyzed.

RESULTS: The pharmacokinetic parameters of ChA alone, the extracts of Lonicera japanica, and the mixture of ChA, baicalin, and Forsythia suspense were as followed: Cmax (2.350 ± 0.483, 1.655 ± 0.576, 2.332 ± 0.606 μg/mL), AUC0-∞ (6.324 ± 1.853, 4.216 ± 1.886, 6.074 ± 1.473 μg·h/mL), t1/2 (0.911 ± 0.187, 1.204 ± 0.309, 1.094 ± 0.193 h), and Tmax (1.861 ± 0.499, 1.000 ± 0.459, 1.833 ± 0.279 h). Accumulative fraction excretion of ChA in urine were 0.73 ± 0.55, 1.25 ± 1.23, 1.05 ± 0.96%, while that in faeces were 0.68 ± 0.94, 0.19 ± 0.40, and 1.76 ± 3.57%.

DISCUSSION AND CONCLUSION: Co-existing compounds in SHL have no effect on the absorption of ChA, while the concomitant compounds in Lonicera japanica could decrease that of ChA. ChA in Beagles might have high biological transformation.