Dietary supplementation with omega-3 polyunsaturated fatty acid-rich oils protects against visible-light-induced retinal damage in vivo

The effects of administering omega-3 (omega-3) polyunsaturated fatty acid (PUFA)-rich oils on visible-lightinduced retinal damage were investigated in rabbits. The mole percentages of alpha-linolenic acid in sea buckthorn berry oil, sea buckthorn oil (SO), sea buckthorn seed oil and flaxseed oil (FO) were 2.12%, 12.98%, 31.56% and 55.41%, respectively. Algal oil (AO) contains 33.34% docosahexaenoic acid. SO has the highest total phenolic content (63.42 +/- 0.59 mg SAE per 100 g) amongst these oils. The administration of SO, FO and AO provided structural and functional protection to the retina. In the retina, we observed a significant increase in the levels of DHA in the AO group compared with the normal group. The mechanism of retinal protection by SO, FO and AO involves up-regulating the expression of nuclear factor erythroid-2 related factor 2 and haem oxygenase-1. The levels of interleukin-1 beta, tumour necrosis factoralpha, interleukin-8, and cyclooxygenase 2 in the retina were significantly reduced with AO treatment. The administration of AO resulted in the down-regulation of nuclear factor kappa B mRNA expression. In addition, the treatment with AO significantly attenuated the light-induced apoptosis and angiogenesis in the retina. These results suggest that dietary omega-3 PUFA-rich oils protect against visible-light-induced retinal damage.