Apical sodium-dependent bile acid transporter, drug target for bile acid related diseases and delivery target for prodrugs: Current and future challenges.

Apical Sodium-dependent Bile Acid Transporter (ASBT) actively reabsorbs bile acids (BAs) from the gut lumen. This process is a critical step in the enterohepatic circulation (EHC) of BAs and plays important roles in the homeostasis of BAs in the body. Therefore, ASBT is considered a favorite target for intervention to regulate the levels of BAs, cholesterol, lipid and glucose etc. In addition, ASBT is also a popular delivery target for developing prodrugs, due to its intestinal localization, high expression and high uptake capacity. In the past ten years, ASBT has been the focus by both academia and pharmaceutical industry as research targets not only for BA-related diseases but also for prodrug delivery. Numerous studies have been published and many candidate ASBT inhibitors are being developed. Here we review and summarize the current states of ASBT research with a focus on the therapeutic applications of ASBT as a target for therapy as well as a delivery target for prodrugs. The current and future challenges in ASBT research and outlook of drug developments are discussed.