Protective Effect of Zeaxanthin against Tunicamycin-induced Cell Damage in SH-SY5Y Cell

Abstract

Endoplasmic reticulum (ER) stress and the resulting neuronal cell damage have been implicated in the development and progression of Alzheimer’s disease. Tunicamycin (TM) induces ER stress in vitro, and the protective effects of the carotenoid zeaxanthin against the effects of TM have recently been studied. Zeaxanthin has been shown to hold several beneficial health properties in human studies. The protective role of zeaxanthin against the toxic effects of TM has recently been studied for the first time. The present study investigated whether zeaxanthin protects SH-SY5Y cells against TM-induced cell damage in vitro. Both pretreatment and post-treatment with zeaxanthin increased cell viability and suppressed lactate dehydrogenase release compared to levels in controls. Further, we found that zeaxanthin considerably ameliorated TM-induced cell damage by protecting the integrity of the mitochondrial membrane decreasing caspase-3 activity, and by reducing the apoptosis rate as well as the expression of the ER stress biomarker GRP78. Modulation of GRP78 may be one of the mechanisms by which zeaxanthin affects cell viability. Our results indicate a potential application of zeaxanthin in the development of new therapeutic drugs for the treatment of Alzheimer’s disease.