Toxicity and antiproliferative effect of aclacinomycin A on RPE cells in vitro

Curcumin inhibits human retinal pigment epithelial cell proliferation

Proliferative vitreoretinopathy (PVR) is a common cause of intraoperative failure following retinal reattachment surgery and is mediated in part through the migration, de-differentiation and proliferation of retinal pigment epithelial (RPE) cells. Given the cytotoxic effects of curcumin on epithelial and endothelial cells, in this study, we assessed the effects of curcumin on human RPE (hRPE) cell proliferation. WST-1 analysis revealed that curcumin significantly inhibited primary hRPE cell proliferation in a dose- and time-dependent manner (P<0.001) with the greatest inhibition observed at the dose of 15 μg/ml curcumin. Flow cytometric analysis indicated that the cytotoxic effects of curcumin on hRPE cell proliferation were mediated by cell cycle arrest at the G0/G1 phase and the induction of apoptosis (both P<0.001), which was confirmed by ultrastructural analysis using transmission electron microscopy. Furthermore, western blot analysis revealed that curcumin induced p53 and p21^WAF1/CIP1 expression with a concomitant decrease in proliferating cell nuclear antigen protein levels (P<0.05). Curcumin effectively inhibited primary hRPE cell proliferation, which may be mediated by the p53 pathway. Further in vivo studies are required in order to fully explore the therapeutic potential of curcumin for PVR.

Inhibitory effect of epigallocatechin gallate (EGCG), resveratrol, and curcumin on proliferation of human retinal pigment epithelial cells in vitro

PURPOSE

To investigate potential inhibitory effects of three polyphenolic agents, epigallocatechin gallate (EGCG; from green tea), resveratrol (from red wine), and curcumin (from turmeric), on the proliferation of human retinal pigment epithelial (RPE) cells and to elucidate unwanted effects.

METHODS

ARPE19 cells and primary human RPE cells were cultured in the presence of various concentrations of EGCG, resveratrol, or curcumin, and compared with controls. The number of viable cells was determined after 24, 48, and 72 hr by flow cytometrical enumeration. Furthermore, cell division was measured by dye dilution assay using carboxyfluorescein succinimidyl ester (CFSE), cell death by Hoechst 33258 staining, and apoptosis by staining for active caspase 3/7 and 8.

RESULTS

The three drugs inhibited the increase of RPE cell numbers at all time points, with resveratrol being the most efficient and curcumin being the least efficient. EGCG inhibited cell proliferation with intermediate efficiency, and showed little induction of cell death. Resveratrol almost completely suppressed cell proliferation, and induced RPE cell necrosis and caspase 3/7- and caspase 8-dependent apoptosis. Curcumin inhibited RPE cell increase exclusively by inducing caspase 3/7-dependent but caspase 8-independent cell death and necrosis.

CONCLUSIONS

All three polyphenols tested reduced the absolute number of cells, but had different effects on cell proliferation, apoptosis, and necrosis. Resveratrol was most potent and EGCG induced the least cell death. These polyphenols may aid treatment of proliferative vitreoretinopathy (PVR).

Effect of topical aclacinomycin on glaucoma filtration surgery in rabbits

A prospective, randomized, double-masked and placebo-controlled study was performed to compare the effects of a single 5-minute intraoperative exposure to aclacinomycin (AMC) 0.4 mg/ml or 0.8 mg/ml with control eyes treated with saline solution on the success of glaucoma filtration surgery in 26 rabbits. Intraocular pressure (IOP), bleb survival, fistula patency and complications were evaluated. The results showed that IOP in the eyes treated with AMC was significantly lower than that in the control eyes from days 5-40 in the 0.4 mg/ml group and from days 5-20 in the 0.8 mg/ml group. The bleb survival lasted significantly longer in the two treated groups than in the control group and in the AMC 0.4 mg/ml group than in the AMC 0.8 mg/ml group. At 40 days, the rate of sclera fistula occlusion was 0% in the AMC 0.4 mg/ml eyes, 43.8% in the AMC 0.8 mg/ml eyes, and 100% in the control eyes. Significant complications, such as anterior chamber inflammation, hyphema, moderate and severe corneal haze, dense corneal neovascularization and mild cataract occurred only in the eyes treated with AMC 0.8 mg/ml. The results indicated that intraocular treatment with AMC at a dose of 0.4 mg/ml had a markedly beneficial effect on IOP, bleb appearance and fistula patency after experimental filtration surgery in rabbits.