AIM: To investigate the anti-aging effect and its potential mechanisms of simvastatin on retinas of physiological aging rats.

METHODS: Totally 40 three-month old healthy SD rats which had no eye diseases, were randomly assigned into two groups: simvastatin group(n=20)and control group(n=20). All rats were cultivated under the same conditions until they were nine-month old when interventions started to be given. Simvastatin group was given intragastric administration of 5mg/kg simvastatin every day until 17-month old. Control group was given intragastric administration of same amount of saline gavage. Retinal thickness was measured by HE staining, while Cu-Zn-SOD, NOX2, Bcl-2 and Bax were determined by immunohistochemistry(IHC).

RESULTS:HE staining showed that the retinal structure was clearer; the morphology of cell was more homogeneous; the number of cells was more stable and the structure of retinal pigment epithelium was more compact when compared with control group. Thickness of retinal neuroepithelium layer and retinal pigment epithelium increased significantly in the simvastatin group. Immunohistochemistry analysis showed that the expressions of Cu-Zn-SOD and Bax statistically increased while the NOX2, Bcl-2 as well as Bcl-2/Bax decreased in simvastatin group when compared with control group(P<0.05).

CONCLUSION: Simvastatin plays a protective role in retinal aging by decreasing oxidative stress reaction and promoting cell apoptosis.