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Isorhapontigenin has been proposed as a better alternative for oral administration than the famous resveratrol, as it shares many biological activities, but with a structure that could make its delivery easier. Although this hydrophobic structure could enhance bioavailability, it could also be a disadvantage in the development of products. In this research, we study the antiproliferative activity of this stilbene against colorectal cancer and overcome its limitations through molecular encapsulation in cyclodextrins. The cytotoxic activity against human colorectal cancer cells of isorhapontigenin was similar to that of resveratrol or piceatannol, supporting its use as a bioactive alternative. The study of the encapsulation through fluorescence spectroscopy and molecular docking revealed that the complexation satisfies a 1:1 stoichiometry and that HP-β-CD is the most suitable CD to encapsulate this stilbene. Through a spectrophotometric assay, it was observed that this CD could double the basal water solubility, exceeding the solubility of other hydroxylated stilbenes. The stability of these inclusion complexes was higher at a pH below 9 and refrigeration temperatures. Moreover, the use of CDs retained more than 78% of isorhapontigenin after storage for 12 weeks, compared to 15% in free form. Overall, these findings could help design novel formulations to better deliver isorhapontigenin. [ABSTRACT FROM AUTHOR]

It has been argued that methoxylated stilbenes are better candidates for oral administration than hydroxylated stilbenes, including resveratrol, as they share many biological activities but have better bioavailability. By contrast, they have a disadvantage to consider, i.e., their lower hydrophilic character that leads to precipitation issues in the final product. In this work, we analysed and compared the growth inhibition of colorectal cancer cells of the methoxylated stilbene rhapontigenin and some analogues and overcame potential problems in the development of fortified products by designing inclusion complexes. Among several cyclodextrins, we found the one that best fit the molecule by physicochemical and bioinformatics assays. The stoichiometry and the encapsulation constants with natural and modified cyclodextrins were determined by fluorescence spectroscopy. The most promising complexes were analysed at different temperature and pH conditions, determining the thermodynamic parameters, to discover the optimal conditions for the preparation and storage of the products. The results showed that rhapontigenin solubility and stability were significantly improved, achieving a sevenfold increase in water solubility and maintaining more than 73% of the stilbene after three months. These findings could be of great interest for industries that aim to deliver novel bioactive compounds with higher solubility and lower degradation. [ABSTRACT FROM AUTHOR]