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Purpose: The main characteristic of proliferative vitreoretinopathy (PVR) is migration, adhesion, and epithelial-mesenchymal transition (EMT) of retinal pigment epithelial cells (RPE). Eupatilin is a naturally occurring flavone that has the potential to inhibit cell proliferation and EMT. However, its efficacy on the PVR model induced by transforming growth factor-2 (TGF-β2) is unknown. In this study, the potential effect of eupatilin on proliferation and EMT in the treatment of RPE was investigated., Methods: Serum starved human RPE cells (ARPE-19) were treated with 10 ng/ml TGF-β2 alone or co-treated with 25 μM eupatilin for 48 h. Quantitative real-time PCR and Western blot analysis were used to assess targets at the mRNA and protein expression level, respectively. Apoptosis and cell cycle progression was assessed by image-based cytometry. The effect of treatment on cell migration was evaluated by wound healing assay., Results: Eupatilin inhibited TGF-β2-induced RPE cell proliferation via regulating the cell cycle and inducing apoptosis. TGF-β2 upregulated mRNA expression of mesenchymal markers fibronectin and vimentin was significantly downregulated by the treatment, while the epithelial markers E-cadherin and occludin expression was upregulated. The therapy significantly suppressed TGF-β2 encouraged cell migration through downregulating the expression of transcription factors Twist, Snail, and ZEB1 induced by TGF-β2. Furthermore, eupatilin significantly inhibited the expression of MMP-1, -7, and -9, and suppressed NF-κB signalling., Conclusion: These results suggest that eupatilin could inhibit the proliferation and transformation into fibroblast-like cells of RPE cells; thus the agent may be a potential therapeutic value in treating PVR.

Purpose: Proliferative vitreoretinopathy (PVR) occurs in approximately 5-10% of patients after retinal detachment surgery. Neferine is a bis-benzylisoquinoline alkaloid found in the green seed embryos ( Nelumbo nucifera ) of the lotus flower and has various properties, such as being antithrombotic, antioxidant, neuroprotective, anticancerous, and anti-inflammatory. Although the effects of neferine on the proliferation and migration of cancer cells have been partially shown, their possible role and the mechanism of action on PVR remain unclear. Materials and methods: To mimic a PVR model in vitro , retinal pigment epithelial (RPE) cells were exposed to epidermal growth factor (EGF) and treated with various concentrations of neferine. Cell viability was determined by MTT test. Cell-cycle phase distribution and cell migration were examined by image-based cytometry and wound healing test, respectively. Messenger RNA (mRNA) and protein expression were determined by RT-qPCR and Western blotting, respectively. Results: Stimulation of the cells with EGF significantly increased the rate of proliferation, whilst treatment with low concentrations of neferine-reduced proliferation to a level equal to that seen in untreated cells. Neferine significantly downregulated EGF-increased cell viability, and survivin mRNA expression was depressed to the basal level. In addition, neferine treatment contributed to cell proliferation loss by upregulating p21 and p27 expression leading to cycle arrest at the G1 phase. The treatment significantly inhibited cell migration by upregulating the expression of epithelial markers, such as E-cadherin and occludin, and decreased MMP2, MMP9, α-SMA, and vimentin. Neferine treatment markedly reduced phosphotidyl inositol 3-kinase (PI3K), AKT, p-p38 mitogen-activated protein kinase (MAPK), and NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) protein expression. Conclusion: It can be considered that neferine may be a potential candidate molecule in the treatment of PVR by inhibiting cell proliferation and the migration of EGF-induced RPE cells through the modulation of various transcriptional activities.