Inhibition effect of curcumin on the proliferation of rabbit retinal pigment epithelial cells

Objective To observe the inhibition effect of curcumin on the proliferation of rabbit retinal pigment epithelial (RPE) cells and investigate its mechanism.Methods The 4th generation of RPE cells were selected and divided into curcumin group and blank control group.The concentration of curcumin included 10,15,and 20 μg/ml.The MTT assay was used to evaluate the inhibition effect on the proliferation of RPE cells at the 24th,48th,72nd and 96th hour after cultured with curcumin (10,15,and 20 μg/ml).The IC50 value of curcumin at different time points were calculated by Linear Regression.Flow cytometry was used to detect the effect on the cell cycle at the 72nd hour after cultured with eurcumin (15 μg/ml) ;the expression and apoptosis of proliferating cell nuclear antigen (PCNA) were also determined at the 24th,48th,and 72nd hour after cultured with curcumin (15 μg/ml) respectively.The configuration of RPE cells were observed by transmission electron microscope.Results The IC50 value of curcumin at the 24th,48th,72nd and 96th hour was 29.31,17.50,13.24,and 10.99 μg/ml respectively.Cell cycel analysis indicated that cureumin blocked cells in G0/G1 phase.At the 24th,48th,and 72nd hour after cultured with curcumin (15 μg/ml),the expression of PCNA of RPE cells were 565.04±23.60,473.61± 36.88,and 396.15±32.45;the apoptosisrate were (12.83±0.13)%,(32.27±4.51)%,(56.81± 8.67)%,respectively.The differeces of curcumin groups compared with the control group were significant (P<0.05).Apoptosis of RPE cells was observed under transmission electron microscope.Conclusions Curcumin can inhibite the proliferation of RPE cells by inhibit the synthesization of PCNA and inducing the apoptosis of RPE cells.Curcumin may become a potential drug to prevent and treat PVR. Key words: Curcumin/administration & dosage; Pigment epithelium of eye; Cell proliferation/drug effects; Vitreoretinopathy,proliferative/drug therapy; Animal experimentation