Honey as a natural absorption enhancer: Mechanisms underlying the improved oral bioavailability and bioactivity of Astragalus flavonoids

Astragalus is a functional plant with notable medicinal and nutraceutical value, and its combination with honey represents a classic pairing in traditional dietary therapy. To address the low oral bioavailability of Astragalus flavonoids (AFs, including calycosin-7-O-β-D-glucoside, ononin, calycosin, and formononetin), the primary bioactive components of Astragalus, our study demonstrated that honey significantly increases the systemic exposure of AFs, thereby enhancing oral bioavailability. These enhancement effects are attributed to the supramolecular structures in honey that interact with AFs through intermolecular non-covalent interactions, and reversible modulation of tight junction barriers by honey, which facilitates the paracellular absorption of AFs. Furthermore, honey’s absorption-enhancing effects were validated by the enhanced Qi-tonifying (enhancement of the body’s vital energy to defend illnesses) efficacy observed in the AFs-honey combination. Our findings provide scientific references for the potential application of honey as a natural absorption enhancer, while offering novel insights into the traditional combination of Astragalus and honey.