Coconut oil protects against light-induced retina degeneration in male Wistar rats

The retinoprotective effect of Cocos nucifera oil (CNO) was investigated. Twenty male Wistar rats weighing 140 g and 180 g were randomly divided into four groups comprising of five animals each. The control group received distilled water. Retinal degeneration was induced in the remaining three groups by exposing the animals to 5,000 lux of bright white light for two hours. Prior to the light exposure, the light model group (LMG) received distilled water for 14 days, low Cocos nucifera oil (LCNO) group received 5 ml/kg of CNO for 14 days, and the high Cocos nucifera oil (HCNO) group received 10 ml/kg of CNO for 14 days. The treatments continued for 7 days after exposure to light. On the eight day, the animals were euthanised and their retinas isolated. The right retinas and occipital cortices of the animals were prepared for histological evaluation while the homogenates of the left retinas were used for biochemical assay. The results show that CNO significantly (p < 0.05) reduced caspase-3 activity from 1.15 ± 0.054 ng/ml to 0.434 ± 0.095 ng/ml (LMG versus LCNO) and malondialdehyde concentration. There was no significant difference in the total antioxidant capacity in the retinas of the rats. However, LMG showed a significant increase in catalase activity. CNO was able to preserve the retinal morphology while LMG showed a distorted retinal layer and significant reduction (p < 0.05) in retina thickness. CNO was unable to prevent perineural vacuolations in the occipital cortices of the rats. In conclusion, Cocos nucifera oil produced retino-protective effect via anti-oxidative and anti-apoptotic mechanisms.