β-Cyclodextrin as a green booster for the extraction of polyphenols from blackthorn fruits: Bioactivity determination and molecular docking analysis

Abstract

Blackthorn fruits are rich source of polyphenols that exert numerous biological activities. But, diverse structure and polarity of phenolic compounds limit their extractability and bioavailability. Therefore, the efficiency of a green co-solvent β-cyclodextrin was examined in boosting the blackthorn polyphenols extraction. Compared to water, as the greenest solvent, β-cyclodextrin was the most efficient in the extraction of flavonoid glycosides quercetin 3-O-glucoside and cyanidin 3-O-glucoside with the extraction rate increase of over 50 % and 40 %, respectively.The second advantage of the β-cyclodextrin use was its intrinsic capability of simultaneous encapsulation of the compounds, through inclusion complexes formation. Scanning electron microscopy, thermogravimetric analysis, and controlled release of the dominant blackthorn polyphenols were used for the encapsulation confirmation and physico-chemical characterization. Encapsulation process reached the efficiency of 76.73 %, providing amorphous particles in the micrometer scale. The effect of the encapsulates on the growth of human MCF7, HT-29, and MRC-5 cells was evaluated in vitro. In silico molecular docking analysis was performed to generate data about the most probable ligand poses and binding mechanisms of β-cyclodextrin encapsulated blackthorn polyphenols. Flavonoid glycosides were most preferably extracted and encapsulated. Rings A and C of flavonoid core enter the hydrophobic hole of β-cyclodextrin and hydrogen bonds are the most responsible for the complex stabilization.