Effect of crocin on glycated human low-density lipoprotein: A protective and mechanistic approach

Human low-density lipoprotein (LDL) is known to have a role in coronary artery diseases when it undergoes modification due to hyperglycaemic conditions. Plant products like crocin play an essential role in protecting against oxidative stress and in the production of advanced glycation end-products (A.G.E.s). In this study, the anti-glycating effect of crocin was analyzed using various biochemical, spectroscopic, and in silico approaches. Glycation-mediated oxidative stress was confirmed by nitroblue tetrazolium, carbonyl content, and lipid peroxidation assays, and it was efficiently protected by crocin in a concentration-dependent manner. A.N.S. fluorescence, thioflavin T (ThT) assay, and electron microscopy confirmed that the structural changes in LDL during glycation lead to the formation of fibrillar aggregates, which can be minimized by crocin treatment. Moreover, secondary structural perturbations in LDL were observed using circular dichroism (CD) and Fourier transform infrared spectroscopy (FTIR), where crocin was found to prevent the loss of secondary structure in glycated LDL. Spectroscopic studies like U.V. absorbance, fluorescence spectroscopy, CD, FTIR, and fluorescence resonance energy transfer (FRET) provided insights into the interaction mechanism between LDL and crocin. Molecular docking supports these results with a highly negative binding energy of -10.3 kcal/mol, suggesting the formation of a stable ldl-crocin complex. Our study indicates that crocin may be a potent protective agent against coronary artery diseases by limiting the glycation of LDL in people with such disorders.