METHODS: Human retinal pigment epithelial cells were cultured in three groups, normal control group, high glucose group and intervention group of high glucose aggravated PolyphyllinⅠ, testing after 12h of intervention culture. Normal control group:5.5mmol/L glucose concentration routine culture; high glucose group:25mmol/L high glucose was added to the medium to establish the model; high glucose aggravated PolyphyllinⅠdrug intervention group: high glucose 25mmol/L, 3μg/L PolyphyllinⅠdrug was added to the medium. Immunofluorescence staining assays to observe expression of the Visfatin and VEGF in human retinal pigment epithelial cells; real-time PCR assays for relative expression of Visfatin and VEGF mRNA in epithelial cells; and western-blot assays for Visfatin and VEGF proteins in epithelial cells.

RESULTS: Immunofluorescence detection revealed that Visfatin and VEGF were weakly positive in normal retinal pigment epithelial cells. Visfatin and VEGF were strongly positive in high glucose group. Visfatin and VEGF fluorescence in the drug intervention group was significantly weakened in the higher sugar group. RT-PCR showed that the expression level visfatin mRNA high sugar group was significantly higher than that of normal group and intervention group(t=4.24, 3.89, P<0.05). VEGF mRNA expression was significantly higher in high glucose group than in normal group and intervention group(t=3.53, 2.57, P<0.05). Western-blot results showed that the protein expression of visfatin and VEGF in high sugar group was significantly higher than that in control group and intervention group(t=3.62, P=0.01; t=3.79, P<0.01).

CONCLUSION: The high glucose environment can stimulate the increased expression of Visfatin in retinal pigment epithelial cells, Polyphyllin I can inhibit the expression of Visfatin in retinal pigment epithelial cells in high glucose environment, which may provide a new idea for the treatment of diabetic retinopathy.