[Protective effect of lutein against blue light-induced retinal damage in rat]

To investigate the effect of lutein on rat retina blue light damage.

Sprague-Dawley rat were randomly separated into 6 groups: normal control, model control, solvent control, low-dose, media-dose, and high-dose. The concentration of lutein solution in the low-dose, media-dose, and high-dose groups are 0.5 mg/ml, 1.0 mg/ml, 2.0 mg/mI respectively. Mix sodium chloride and Tween 80 together at the ration of 1:9 as the solvent. Solvent and lutein solution were injected into rats' vitreous body of the solvent group and the lutein groups respectvely (the injection volume is 5 microl), dark adaptation 24h, then the rats exposed to the blue light equipment 2h to set up the light-damage animal model. After light exposure, the rats were raised in darkness for 72 hours. Then the rats were killed, the eyes were removed and were processed to paraffin section for microscopy, then we observed the changes of retina morphous, measured the thickness of the outer nuclear layer (ONL thickness), and counted the number of apoptotic photoreceptors to compare the effect of lutein on light-damage of retina among different dosages.

Comparing with the model-control group, the rats of lutein group had more clearly demarcated retina structure and more ordered cells. After detected under microscopy, we found that the ONL thickness (40 x 10 times, mm) of the rats of normal control group was 21.25 +/- 1.04. And the ONL thickness of the rats of lutein groups were 15.00 +/- 5.58, 11.75 +/- 4.20 and 14.75 +/- 3.96, from low dosage to high dosage, which was significantly (P < 0.01) higher than those of the rats of model control group (3.25 +/- 1.48) and solvent control group (3.25 +/- 0.89). Compare the number of apopotic photoreceptors, there is no significant differences among groups.

In the experiment conditions, the effect of prevention of lutein on retina light damage was significant. The result provided an important base on the application of lutein on crowd.