Investigation of the absorption mechanisms of baicalin and baicalein in rats

Multiple-Ascending-Dose Pharmacokinetics and Safety Evaluation of Baicalein Chewable Tablets in Healthy Chinese Volunteers

“…Zhang [28] demonstrated an extensive first-pass glucuronidation of baicalein in both liver and intestine and the P450-mediated hydroxylation of baicalein was not significant in either human liver or intestine. It was reported that intestinal bacteria could produce beta-glucuronidase, which could hydrolyze baicalin into baicalin [29]. Thus, the glucuronidation metabolism of baicalein and the intestinal bacteria can also contribute to the lack of dose proportionality of baicalein and the multi-peaks of baicalein and baicalin in human subjects.…”

“…This phenomenon could be explained by the fact that baicalein is predominantly metabolized by glucuronidation and is excreted mainly in the metabolized form in urine and feces. The high amount of baicalein in the feces could be caused by intestinal bacteria, which can hydrolyze some glucuronidation metabolites back into baicalein [29].…”

Nanoemulsion improves the oral bioavailability of baicalin in rats: in vitro and in vivo evaluation

“…4,7,8 After oral administration of baicalin and baicalein in rats, the absolute bioavailability was 2.2% and 27.8%, respectively. 9 It was concluded that the oral bioavailability of baicalin was greatly improved after administration of baicalein.…”

Protective role of intestinal bacterial metabolism against baicalin-induced toxicity in HepG2 cell cultures

“…Meanwhile, the metabolism of baicalin is of interest. For the absorption of baicalin in intestine, it should be fi rst hydrolyzed by intestinal microfl ora to baicalein, which can be absorbed and further metabolized to baicalin again or baicalein 6-glucuronide in body (Xing et al, 2005;Taiming and Xuehua, 2006;Zhang et al, 2007a). The UDP-glu- curonosyltransferases expressed in hepatic and intestinal tissues are able to catalyze the unique metabolism of baicalein to the parent baicalin in body (Zhang et al, 2007b).…”