Bioavailability Study of Berberine and the Enhancing Effects of TPGS on Intestinal Absorption in Rats

Abstract

Berberine chloride (BBR) is a natural isoquinoline alkaloid extracted from medicinal herbs. It has been reported that the intestinal absorption of BBR is very low. In this study, the absolute bioavailability of BBR was studied, and the enhancing effects of D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) on intestinal absorption were investigated in rats. BBR injection was administrated via the femoral vein at a dose of 1.0 mg kg(-1) in intravenous group, and BBR oral formulations were administrated by oral gavage at a dose of 100 mg kg(-1) in BBR control (control) group and BBR-TPGS (test) group, respectively. The result showed that BBR had a very low absolute bioavailability of 0.68%, and TPGS could enhance intestinal absorption of BBR significantly. TPGS at a concentration of 2.5% could improve peak concentration (C(max)) and area under the curve (AUC(0-36)) of BBR by 2.9 and 1.9 times, respectively. The absorption enhancing ability of TPGS may be due to its ability to affect the biological activity of P-glycoprotein and thereby reduce the excretion of absorbed BBR into the intestinal lumen. This study indicated that absolute bioavailability of BBR was 0.68% in rats, and TPGS was a good absorption enhancer capable of enhancing intestinal absorption of BBR significantly.

Berberine, a plant alkaloid with lipid- and glucose-lowering properties: From in vitro evidence to clinical studies

“…Similarly, D-α-tocopheryl polyethylene glycol 100 succinate (TPGS), a water-soluble form of vitamin E that inhibits the biological activity of P-gp, increases BBR absorption in rats [120]. A nanosuspension composed of BBR and TPGS shows a superior capacity to reduce glucose, TC and body weight compared with an equivalent dose of metformin or BBR in diabetic C57BL/6 mice [121]..…”

Folic acid-functionalized drug delivery platform of resveratrol based on Pluronic 127/D-α-tocopheryl polyethylene glycol 1000 succinate mixed micelles

“…This relatively low CMC indicated that the mixed micelles had intensive thermodynamic stability. 30,31 resveratrol release from mixed micelles in vitro…”

Berberine-induced Inactivation of Signal Transducer and Activator of Transcription 5 Signaling Promotes Male-specific Expression of a Bile Acid Uptake Transporter

“…The relatively low bioavailability of BBR was suggested to be due, at least in part, to its poor intestinal absorption (20). BBR was identified as a substrate for P-glycoprotein, and the action of P-glycoprotein played an important role in the absorption of BBR (21).…”