Abstract: The purpose of this study was to explore the protective effect of wolfberry and mulberry polysaccharides combined with lutein on visible light-induced retinal degeneration through their antioxidant activity. Pigmented rabbits were exposed to visible light to induce retinal light damage and then treated with different doses of polysaccharides extracted from a mixture of both dried fruits (1:1, m/m) and lutein for 21 days. Afterwards, lipid peroxidation, protein oxidation, DNA oxidation biomarkers and antioxidant parameters in the retina were evaluated. The results revealed that light exposure induced significant increases in oxidative damage to lipids, proteins and DNA in the retina of pigmented rabbits. In contrast, co-treatment with medium and high doses of polysaccharide extracts and lutein decreased the contents of malondialdehyde (39.02%; 54.08%, P < 0.05), 4-hydroxy azelaic acid (32.86%; 41.78%, P < 0.05), 3-nitro-tyrosine (17.20%; 19.69%) and 8-hydroxy-deoxyguanosine (6.12%; 28.81%), paralleling with increased activities of catalase (1.96-fold; 2.40-fold, P < 0.05) and total antioxidant capacity (1.98-fold; 2.11-fold, P < 0.05). Accordingly, combined intervention with wolfberry and mulberry polysaccharides and lutein can significantly alleviate visible light-induced retinal oxidative damage in pigmented rabbits.

Key words: wolfberry polysaccharides, mulberry polysaccharides, lutein, visible light-induced retinal degeneration, antioxidant effect