Propolis as a promising functional ingredient: a comprehensive review on extraction, bioactive properties, bioavailability, and industrial applications

Propolis is a resinous complex mixture made from plant resins collected by worker bees and mixed with their own secretions. It is rich in polyphenols and flavonoids and thus has a wide range of biological activities and is considered a functional source for promoting human health. However, propolis and its bioactive compounds have poor water solubility, rapid and intense metabolism, and low oral bioavailability, which limits their wide application. In this paper, the main bioactive substances in propolis were summarized, and the biological characteristics and therapeutic potential of propolis and its bioactive substances were discussed. In addition, this paper discussed the factors affecting the bioavailability of propolis and its functional ingredients, focusing on the research progress in improving the bioavailability and bioactivity of propolis and its functional ingredients using nanoencapsulation technology. Finally, the current situation of the global propolis market and the applications of propolis products in the pharmaceutical, food, cosmetic and other industrial fields were discussed, providing useful references for promoting the development of the propolis industry.