Protective effect of crocin against glycated LDL-induced cytotoxicity and oxidative stress in isolated human erythrocytes.

Glycation of low-density lipoprotein (LDL) occurs when blood glucose levels are high, as in diabetic patients. This can lead to abnormal cholesterol transport in the body. Glycated LDL (G-LDL) is harmful and triggers oxidative stress in human erythrocytes. The present study investigated the protective effect of crocin, found in saffron, against G-LDL-induced cytotoxicity, oxidative damage, and formation of reactive species in human erythrocytes. These parameters were assessed in isolated human erythrocytes exposed to 6 mg/ml G-LDL, with and without varying concentrations of crocin (0.5, 1.0, 1.5 mM). Increased hemolysis, methemoglobin, and oxoferrylHb were seen in G-LDL alone-incubated cells. A significant increase in reactive species in G-LDL-exposed erythrocytes led to enhanced oxidation of lipids, proteins, and thiols. The activities of certain key antioxidant and membrane-bound enzymes were reduced. The antioxidant capacity of cells was compromised as indicated by a diminished ability to neutralize free radicals and donate electrons. G-LDL significantly altered surface morphology, forming echinocytes and agglutinating the cells. All these characteristics were significantly restored when erythrocytes were pre-treated with crocin, before incubation with G-LDL, in a crocin concentration-dependent manner. Furthermore, erythrocytes incubated with 1.5 mM crocin alone did not show alterations in any of the above parameters, indicating that crocin was not toxic to these cells. These results clearly show that crocin is strongly cytoprotective against G-LDL-induced damage and toxicity in erythrocytes. Hence, it can be used as an efficient dietary antioxidant in various atherosclerotic cardiovascular disorders, as seen in diabetic patients.