Research progress on berberine with a special focus on its oral bioavailability.

The natural product berberine (BBR) has become a potential drug in the treatment of diabetes, hyperlipidemia, and cancer. However, the oral delivery of BBR is challenged by its poor bioavailability. It is necessary to improve the oral bioavailability of BBR before it can be used in many clinical applications. Understanding the pharmacokinetic characteristics of BBR will enable the development of suitable formulas that have improved oral bioavailability. The key considerations for BBR are how to enhance the drug absorption and to avoid the intestinal first-pass effect. This review summarizes the pharmacological activities of BBR and analyzes the factors that lead to its poor oral bioavailability. In particular, the therapeutic potential of BBR in new indications from the aspect of oral bioavailability is discussed. In conclusion, BBR is a promising drug candidate for metabolic disorders and cancer but faces considerable challenges due to its poor oral bioavailability.