Chrysin-loaded bovine serum albumin particles as bioactive nanosupplements

Development of nanosupplements based on bioactive compounds encapsulation and its incorporation in the diet constitutes a field in exponential growth. Among flavonoids, chrysin (Chrys) shows great antitumor activity but its poor water solubility limits their applications. Bovine serum albumin nanoparticles (BSAnp) with sizes between 13-28 nm were previously prepared by applying a heat-induced self-assembly process, and they were able to load Chrys. Hence, the aim of this study is to provide information about elaboration of Chrys nanosupplements considering the incidence of a freeze-drying process of Chrys-loaded and unloaded BSAnp systems on aqueous redispersibility, and on the preservation of their physicochemical properties examined by DSC, turbidity and DLS measurements. In general, physicochemical properties of Chrys-loaded BSAnp were preserved after freeze-drying application. Cytotoxic activity of the reconstituted powders was assayed on MCF-7 and MDA-MB-231 cell lines (as models of cancer cell lines) by means of MTT assay. Furthermore, the mechanism of cell death was researched by Annexin V-FITC flow cytometry. Apoptosis-mediated cytotoxicity was higher for Chrys-loaded BSAnp in comparison with BSAnp system. The greatest in vitro cytotoxic effect was observed for the smallest sized Chrys-loaded BSAnp, which was obtained at pH 11.0 and 70oC. Finally, this system was subjected to a static in vitro gastrointestinal digestion protocol, and ~14% Chrys was released from BSAnp after digestion. Results would provide a procedure to obtain bioactive nanosupplements in a soluble form, and they would suggest that smaller sized Chrys-loaded BSAnp could be a promising oral delivery system for potential cancer therapies.