Inhibitory effect of curcumin, salvia miltiorrhiza and matrine on IL-1β-induced proliferation of rabbit RPE cells in vitro

Background

Proliferative vitreoretinopathy (PVR) is a common cause of vision loss clinically, and retinal pigment epithelium (RPE) cells play a major part in this disease.Studying the effect of traditional Chinese medicine on RPE cells are of great importance to reveal the pathogenesis and prevention of PVR, which were rarely reported.

Objective

This study was to study and compare the inhibition effect among curcumin, salvia miltiorrhiza and matrine on IL-1β-induced proliferation of rabbit RPE cells.

Methods

RPE cells at passages 3-4 were enrolled for the research and identified by transmission electron microscope.The proliferation effect of IL-1β (2.5, 5.0, 10.0, 20.0 μg/L) and inhibitory effect of curcumin (5, 10, 20 μg/ml) , salvia miltiorrhiza (5, 10, 20 μg/ml) or matrine (100, 200, 400 μg/ml) on RPE cells 24, 48 and 72 hours after cultivation were studied by MTT assay.The 50% inhibitory dose (IC₅₀) of the three medicines were analyzed by regression analysis.The use and feeding of the experimental animals were followed by the ARVO Statement.

Results

RPE cells isolated from the rabbit eye were in round shape and abundant in melanin; The melanin significantly decreased in the fourth generations of RPE cells.Immunohistochemistry showed that the RPE cells was positive for keratin (AE1/AE3). The proliferation rates of RPE cells were statistically different among different concentrations of IL-1β 24, 48 and 72 hours after cultivation (F_time=30.33, P=0.00; F_{concentration}=9.37, P=0.00); The proliferation rates of RPE were significantly different among different time points or different concentrations of IL-1β (all at P<0.05). And the proliferation rate run up to maximum at 10 μg/L after 72 hours of cultivation.The inhibitory rates of the three medicines were statistically different among different time points or different concentrations (curcumin: F_time=128.75, P=0.00; F_{concentration}=334.05, P=0.00.salvia miltiorrhiza: F_time=39.32, P=0.00; F_{concentration}=165.57, P=0.00.matrine: F_time=267.76, P=0.00; F_{concentration}=912.34, P=0.00). The three medicines dose-dependently and time-dependently inhibit IL-1β-induced proliferation of RPE cells, with significant differences between the adjacent time points and concentrations ( all at P<0.05). The IC₅₀ were 26.77, 19.01 and 9.45 μg/ml for curcumin; 33.72, 23.47 and 12.56 μg/ml for salvia miltiorrhiza, 570.96, 352.25 and 97.50 μg/ml for matrine 24, 48 and 72 hours after cultivation.

Conclusions

The proliferation of RPE cells can be stimulated by IL-1β, and the maximal proliferation occurred with a concentration of 10.0 μg/L IL-1β.Curcumin, salvia miltiorrhiza and matrine dose-dependently and time-dependently inhibit proliferation of RPE cells induced by IL-1β.Curcumin is the best medicine to inhibit the proliferation of RPE cells.

Retinal pigment epithelium; Interleukin-1; Proliferative vitreoretinopathy; Curcumine; Salviae miltiorrhizae; Matrine