Profound difference of metabolic pharmacokinetics between pure glycyrrhizin and glycyrrhizin in licorice decoction.
To investigate the difference of metabolic pharmacokinetics between pure glycyrrhizin (GZ) and GZ in licorice decoction, six New Zealand White rabbits were orally given pure GZ and licorice decoction containing equivalent content of GZ in a randomized crossover design. HPLC methods were used for the quantitation of GZ and glycyrrhetic acid (GA) in serum. The results indicated that the areas under curves (AUCs) of GZ and GA after administration of licorice decoction were significantly higher than those after pure GZ. This result was contradictory with that obtained in rats. To explore the mechanism of the pharmacokinetic difference, feces of rabbits, rats, pigs and humans were used to investigate the presystemic metabolism of pure GZ and GZ in licorice decoction. The results indicated that pure GZ was hydrolyzed to GA more rapidly and to a greater extent than that in licorice decoction by various feces. In addition, when pure GZ was fermented, the metabolic profiles of GA and 3-dehydroGA in rabbit feces were quite different from other feces. In conclusion, the bioavailabilities of GZ and GA are significantly better from licorice than from pure GZ in rabbits but the presystemic metabolism of pure GZ in rabbit is rather different from that in rat, pig and human.
Hou
Yu-Chi
YC
School of Chinese Medicine, China Medical University, Taichung, Taiwan 404, R.O.C.
Hsiu
Su-Lan
SL
Ching
Hui
H
Lin
Ya-Tze
YT
Tsai
Shang-Yuan
SY
Wen
Kuo-Ching
KC
Chao
Pei-Dawn Lee
PD
D000818:Animals; D019540:Area Under Curve; D001682:Biological Availability; D006034:Glycyrrhetinic Acid / Q000493:pharmacokinetics; D006035:Glycyrrhiza; D019695:Glycyrrhizic Acid / Q000493:pharmacokinetics*; D008297:Male; D010936:Plant Extracts / Q000493:pharmacokinetics*; D011817:Rabbits
D010936:Plant Extracts; C069074:liquorice decocta; D019695:Glycyrrhizic Acid; D006034:Glycyrrhetinic Acid