OBJECTIVE To investigate the effect of hyperoside on high glucose-induced excessive proliferation of retinal endothelial cells (RECs) and its possible mechanism.

METHODS Diabetic retinopathy (DR) models were established in male Sprague-Dawley (SD) rats. DR rats were treated with low- and high-dose hyperoside (DR+L-HY group and DR+H-HY group). Additionally, the normal control (NC) group, DR non-intervention (DR) group and DR+calcium dobesilate intervention (DR+CD) group were set up. The differences in the number of RECs in retinal blood vessels were observed and compared among all groups after intervention. In addition, RECs were inoculated into cell culture plates after normal culture and subculture. They were divided into 5 groups according to different treatments: normal glucose (NG) group, high glucose (HG) group, mannitol (MT) group, high glucose + low concentration of hyperoside (HG+H100) group and high glucose + high concentration of hyperoside (HG+H400) group. The activity, cell migration and tubule formation of RECs in each group were detected and compared by CCK-8, cell migration and tubule formation assays. Western blot and qPCR were used to detect the expression of NADPH Oxidase 4 (NOX4) and thioredoxin interacting protein (TXNIP) in each group.

RESULTS The number of RECs in the DR group was significantly increased compared to the NC group (P < 0.01). In contrast, the DR+L-HY, DR+H-HY, and DR+CD groups all showed significant decreases in RECs number compared to the DR group (P < 0.05, P < 0.01), and the reduction of RECs in the DR+H-HY group was significantly greater than that in the DR+L-HY group (P < 0.05). Furthermore, the cell activity, migration number and tube formation number of RECs in the HG group were significantly higher than those in the NG group (P < 0.05, P < 0.01). The protein and mRNA expression levels of NOX4 and TXNIP in the HG group were also significantly higher than those in the NG group (P < 0.01). However, the RECs activity, RECs migration number and tube formation number in the HG+H100 group and the HG+H400 group were significantly lower than those in the HG group (P < 0.05, P < 0.01). The expression levels of NOX4 and TXNIP in both groups were significantly lower than those in the HG group (P < 0.05, P < 0.01), and the RECs activity, migration number, tube formation number, and the expression of NOX4 and TXNIP in the HG+H400 group were further significantly decreased compared with those in the HG+H100 group (P < 0.01).

CONCLUSION Hyperoside could significantly inhibit the high glucose-induced excessive proliferation of RECs. The mechanism may be related to the inhibition of NOX4/TXNIP activation in high-glucose environment.