Protective Effect of Astaxanthin on Primary Retinal Cells of the Gerbil Psammomys Obesus Cultured in Diabetic Milieu

Astaxanthin is a major marine carotenoid with powerful antioxidant and neuroprotective properties. The in vitro protective effect of astaxanthin in adult retinal cells of the type-2 diabetic model Psammomys obesus in hyperglycemic conditions was investigated. Primary retinal cells were cultured in normal (5 mM) or high concentrations of glucose (25 and 40 mM) for 5 days and treated with 1-20 μM astaxanthin for the last 48 h of culturing. Mitochondrial dehydrogenase activity and cell viability were assessed using MTT test and trypan blue exclusion dye. Retinal cells were characterized by immunohistochemistry. The results showed that mitochondrial function increased significantly (P<0.05) with 5-20 μM astaxanthin in 25-40 mM glucose. At 10 μM astaxanthin, cell viability recovered to 78.51±5.81% and 54.37±9.64% of control in 25 and 40 mM, respectively. Neurons and glial cells expression were enhanced in elevated glucose conditions. These finding suggest that astaxanthin exerted neuroprotection against high glucose induced- retinal damage. Practical Applications: The xanthophyll astaxanthin is found in many marine food sources such as shrimp. The cytoprotective and antioxidant capacity of astaxanthin in retinal disease has been pointed out and presented as a promising therapeutic strategy. The present study shows that astaxanthin can interfere with hyperglycemia-induced retinal cell death and that primary retinal culture of Psammomys obesus may represent an effective system to explore astaxanthin antioxidant mechanisms in diabetic retinopathy.