The antiglycation effects of three structurally different phytosterols (PS) including stigmasterol, β-sitosterol, and
γ-oryzanol on bovine serum albumin (BSA) were deeply studied in a BSA-glucose model by measuring the
glycoxidation-based products, SDS-PAGE intensity, free lysine, and their fluorescence microscopy clicks. For the
first time, the underlying mechanisms of the antiglycation effects of PS were wholly elucidated by measuring
their interaction ability with BSA and their antiradical activity during the glycation reactions. The results
showed that PS could partially inhibit the formation of advance glycation end products, block some of the lysyl
residues of BSA (Lys127, 357, 434, and 524), prevent the glucose-BAS bonding, and their disaggregation effects
on the glycated BSA. Throughout the underlying mechanism behind the antiglycation activity, PS were found to
structurally quench the fluorescence intensity of BSA in a static mode, leading to fluctuations in its Z-average
size, UV–vis spectrum, and secondary structure. Additionally, PS mitigated the formation the advanced glycation
end products by scavenging the radicals produced during the glycation reactions. Overall, these results unleash
that PS prevent the glycation reactions and their subsequent changes through shielding the NH2 groups via Hbonding
with their eOH-groups and pi-pi interaction of the steroid core, besides the antiradical activity of PS on
the free radicals generating during the glycation reactions.