Investigation of transport of genistein, daidzein and their inclusion complexes prepared with different cyclodextrins on Caco-2 cell line.

Isoflavonoids are widespread constituents in medical plants especially in legumes (Fabaceae), but occur in other different plant families as well (Rosaceae, Iridaceae, Amaranthaceae). Their antioxidant, estrogen-like, anti-inflammatory and analgesic effects make them promising compounds in therapy of important disorders especially in estrogen related diseases. Poor solubility in aqueous system of genistein and daidzein needs a solubility enhancement for pharmaceutical use. These compounds are suitable guest molecules for inclusion complex formation with cyclodextrins (CDs) considering matching their size and polarity. The molecular encapsulation with beta-cyclodextrin (β-CD), gamma-cyclodextrin (γ-CD), hydroxypropyl-beta-cyclodextrin (HP-β-CD) and random methyl-beta cyclodextrin (RAMEB-CD) results in a solid, molecularly dispersed form and in a significantly improved aqueous solubility of genistein and daidzein. Determining enhancement in solubility and bioavailability we investigated the transport of these inclusion complexes across Caco-2 cell line comparing that of the pure compounds and found significant improving effect of the different CD derivatives on membrane permeation of the two isoflavone aglycons.