黄芩苷与黄芩素在离体大鼠肝、肾、小肠及膀胱中代谢的相互转化  

In vitro metabolic interconversion between baicalin and baicalein in the liver,kidney,intestine and bladder of rat

作　　者：刘兆明[1] 马越鸣[1] 王天明[1] 郭忻[1] 

机构地区：[1]上海中医药大学,上海201203

出　　处：《药学学报》2008年第6期664-668,共5页Acta Pharmaceutica Sinica

基　　金：国家自然科学基金资助项目(90409008);上海市重点学科建设项目资助(T0301).

摘　　要：The present study is aimed to investigate the in vitro metabolic interconversion between baicalin（BG） and baicalein（B） in rat liver,kidney,intestine and bladder.BG and B were separately incubated with rat hepatic,renal,and intestinal microsomes,as well as bladder homogenates,for 30 min.The metabolites were identified and quantified by HPLC and metabolic kinetic parameters were obtained by fitting the data to the Michaelis-Menten equation.In hepatic microsomes,renal microsomes and bladder homogenates,but not in intestinal microsomes,BG was transformed into B,the hydrolysis metabolite of BG,with Km values being（44.65±6.01）,（92.73±11.41）,（74.60±3.68） μmol·L-1,respectively,and Vmax values being （12.32±0.56）,（3.30±0.18）,（5.93±0.12） μmol·min-1·g-1（protein）,respectively.In incubations with hepatic,renal,and intestinal microsomes and bladder homogenates,B was also transformed into BG,the glucuronidation metabolite of B,with Km values being（67.46±10.49）,（226.7±71.59）,（177.3±35.85）,and（18.33±2.53） μmol·L-1,respectively,and Vmax values being（14.74±0.97）,（5.91±1.03）,（38.14±3.60）,and（1.22±0.05） μmol·min-1·g-1（protein）,respectively.The results showed that the activity of UDP-glucuronosyltranferase（UGT） in intestinal microsomes was the highest among the four organs,and the activities of UGT were higher than that of glucuronidase（GUS） in hepatic,renal and intestinal microsomes,but the activity of GUS was higher than that of UGT in bladder homogenates.The present study is aimed to investigate the in vitro metabolic interconversion between baicalin （BG） and baicalein （B） in rat liver, kidney, intestine and bladder. BG and B were separately incubated with rat hepatic, renal, and intestinal microsomes, as well as bladder homogenates, for 30 min. The metabolites were identified and quantified by HPLC and metabolic kinetic parameters were obtained by fitting the data to the Michaelis-Menten equation. In hepatic microsomes, renal microsomes and bladder homogenates, but not in intestinal microsomes, BG was transformed into B, the hydrolysis metabolite of BG, with Km values being （44.65 ± 6.01）, （92.73 ± 11.41）, （74.60 ± 3.68） μmol·L^-1, respectively, and Vmax values being （12.32 ± 0.56）, （3.30±0. 18）, （5.93 ± 0. 12） μmol·min^-1·g^-1（protein）, respectively. In incubations with hepatic, renal, and intestinal mierosomes and bladder homogenates, B was also transformed into BG, the glueuronidation metabolite of B, with Km values being （67.46 ± 10.49）, （226.7 ± 71.59）, （177.3 ± 35.85）, and （18.33 ±2.53） μmol·L^-1, respectively, and Vmax values being （14.74 ±0.97）, （5.91 ±1.03）, （38.14 ±3.60）, and （1.22 ± 0. 05） μmol·min^-1 · g^-1 （protein）, respectively. The results showed that the activity of UDP- glueuronosyltranferase （UGT） in intestinal mierosomes was the highest among the four organs, and the activities of UGT were higher than that of glueuronidase （GUS） in hepatic, renal and intestinal mierosomes, but the activity of GUS was higher than that of UGT in bladder homogenates.

关 键 词：黄芩苷 黄芩素 体外代谢 

分 类 号：R282.71[医药卫生—中药学]