Protective effect of paeoniflorin against oxidative stress in human retinal pigment epithelium in vitro.

OBJECTIVE

This study was conducted to determine whether paeoniflorin (PF) could prevent H₂O₂-induced oxidative stress in ARPE-19 cells and to elucidate the molecular pathways involved in this protection.

METHODS

Cultured ARPE-19 cells were subjected to oxidative stress with H₂O₂ in the presence and absence of PF. The preventive effective of PF on reactive oxygen species (ROS) production and retinal pigment epithelium (RPE) cell death induced by H₂O₂ was determined by 2',7'- dichlorodihydrofluorescein diacetate (H₂DCFDA) fluorescence and 3-(4, 5-dimethylthiazol-2-yl)-2, 5 diphenyl tetrazolium bromide (MTT) assay. The ability of PF to protect RPE cells against ROS-mediated apoptosis was assessed by caspase-3 activity and 4', 6-diamidino-2-phenylindole (DAPI) staining. Furthermore, the protective effect of PF via the mitogen-activated protein kinase (MAPK) pathway was determined by western blot analysis.

RESULTS

PF protected ARPE-19 cells from H₂O₂-induced cell death with low toxicity. H₂O₂-induced oxidative stress increased ROS production and caspase-3 activity, which was significantly inhibited by PF in a dose-dependent manner. Pretreatment with PF attenuated H₂O₂-induced p38MAPK and extracellular signal regulated kinase (ERK) phosphorylation in human RPE cells, which contributed to cell viability in ARPE-19 cells.

CONCLUSIONS

This is the first report to show that PF can protect ARPE-19 cells from the cellular apoptosis induced by oxidative stress. The results of this study open new avenues for the use of PF in treatment of ocular diseases, such as age-related macular degeneration (AMD), where oxidative stress plays a major role in disease pathogenesis.