The Experimental Study Of Pirfenidone On Rats Corneal Scarring After Alkali Burn

Purpose:To evaluate the treatment effects of pirfenidone which is anti-fibrosis drug on corneal re-epithelialization and scarring,by the experiment research of pirfenidone on rats model of alkali burn.Methods:Thirty adult healthy Wistar rats of both sexes and weight of 200-300 g were random selected for the study.Six rats were used as normal control group.Twenty-four rats were make alkali burn model on the right eye,and divided into A,B two groups(n=12)after success.The Group A was treated with pirfenidone eye drops(5g/L),and control treatment with phosphate buffered saline(PBS),the treatments of the right eye were administered daily 6 times and continued for 14 days.The area of injured corneal,corneal haze were analyzed at 1d,4d,7d,14 d of post-therapy by slit lamp microscope.At 7d and 14 d of post-therapy,6 rats in the each group were killed and remove their right cornea.To observe all groups structure of the corneal tissue HE staining,the expression of Collagen Ⅳ、α-SMA、VEGF、CD34 was detected by immunofluorescence,and α-SMA、VEGF、PEDF、CD31、CD34 、NF-κB expression in the cornea was examined by Western blotting.Result:1.Pirfenidone significantly(P<0.05)promoted corneal re-epithelialization time and decreased corneal opacity following alkali burn.The corneal re-epithelialization time have significantly difference in the 7 days,but the corneal haze in the 14 days.2.Through of rats corneal tissue HE staining on pirfenidone group and control.the result shows that in 7 days and 14 days after alkali burn,two groups corneal tissue have inflammatory cells,but pirfenidone group was significantly lower than control group.3.Through the immunofluorescence,we know that α-SMA and CD 34 were not expressed in the normal cornea,but Collagen Ⅳ、VEGF expressed on it.After alkali burn all antibody expressed on it,and pirfenidone group Collagen Ⅳ、α-SMA expression was significantly(P<0.05)difference the control group in the 7 days and the 14 days,VEGF、CD34 expression difference in the 14 days.4.The Western blot results showed that PEDF always express on the pirfenidone group and maintain at a certain level,but a-SMA,CD31,CD34,VEGF expression were lower than PBS group and has certain difference.However,there was no significant difference in the expression of NF-κB in the two groups.Conclusion:1.Pirfenidone suppresses Collagen Ⅳ and α-SMA expression in corneal tissue after alkali burn,has inhibitory effect on corneal scarring.2.Pirfenidone has a certain role on the control of corneal neovascularization after alkali burn by inhibits expression of VEGF and promote the PEDF expression.3.Pirfenidone has anti-inflammatory effect on reduces the expression of CD34 and CD31,promotes healing of corneal wounds and inhibits inflammation.