AIM: To investigate the protective effect and mechanism of Danlou tablet on retinal ischemia-reperfusion injury(RIRI)in mice.

METHODS: A total of 40 ApoE^-/- mice were fed with high fat diet for 6 wk, and the RIRI model was established by anterior chamber infusion of pressurized saline. The mice were divided into control group(normal saline for 8 wk), RIRI model group(normal saline for 8 wk), and low-, medium-, and high-dose Danlou tablets groups \〖1, 2, and 4 g/(kg·d), respectively, for 8 wk\〗. The morphological changes of retina were observed by hematoxylin-eosin(HE)staining, retinal cell apoptosis was detected by terminal-deoxynucleoitidyl transferase mediated Nick-End Labeling(TUNEL)staining. The Western-blot assay was used to detect the expression of retinal tissue sample Kelch-like ech-associated protein 1(Keap1), nuclear factor E2 related factor 2(Nrf2), heme oxygenase 1(HO-1), and superoxide dismutase(Sod2)proteins.

RESULTS: Compared with the control group, the mouse retina was atrophic with thinning thickness and increasing cell apoptosis, down-regulation of Sod2 protein expression, and up-regulation of Keap1 protein expression in the RIRI model group(all P<0.01). Compared with the RIRI model group, the retinal thickness increased in the medium- and high-dose of Danlou tablets groups(all P<0.01), and the cell apoptosis of retina decreased in the low-, medium- and high-dose of Danlou tablets groups(all P<0.05). There were no significant differences in the expression of Keap1 and HO-1 proteins of mouse retina tissue in the low-dose of Danlou tablets group(P>0.05). The expression of Sod2, Nrf2 and HO-1 proteins up regulated, and the expression of Keap1 protein down regulated in the medium- and high-dose of Danlou tablets groups(all P<0.05).

CONCLUSION: Danlou tablet can alleviate RIRI-induced atrophy and thinning of retina and retinal cell apoptosis by regulating Keap1-Nrf2/HO-1 signal pathway and reducing oxidative stress.