The Effect Of Xuefu Zhuyu Decoction On Retinal Ganglion Cells After Optic Nerve Injury In Rats

ObjectiveTo evaluate the effects of Xuefu Zhuyu Decoction on traumatic optic neuropathies(TON) after optic nerve injury in rats through the survival ratio of RGCs,the tectology of the retina and optic nerve,the microenvironments of optic nerve restoration,and to investigate the possible mechanisms,which may be valuable as therapeutic agents for TON,and also to provide the new thoughts and methods for the study of Traditional Chinese Medicines's effect on TON.Methods1.To observe the impacts of distilled water,Erigeron,Xuefu Zhuyu Decoction on RGCs after optic nerve injury in rats and selecte the best prescription.2.To observe the retinal thickness and the optic nerve ultrastructure at different times.3.To evaluate the effects of Xuefu Zhuyu Decoction on the microenvironments of the injured optic nerve restoration.The expressions of growth associated protein 43(GAP-43) and rho-associated coiled-coil forming protein kinase(ROCKⅡ) were detected on the 3^rd day and the 1^st,the 2^nd,the 4^th week.Results1.The effect of Xuefu Zhuyu Decoction on RGCsThe average survival ratio of RGCs:The RGCs' survival ratios of Group K(Distilled Water),Group D(Erigeron),Group Z(Xuefu Zhuyu Decoction),Group H(Huoxue Decoction) and Group L(Liqi Decoction) were respectively 62.84%±10.96%,75.76%±8.87%,89.18%±10.59%,69.68%±5.26%and 66.95%±9.12%.The RGCs' survival ratio of Group Z was significantly higher than other groups(P<0.01).2.The effect of Xuefu Zhuyu Decoction on the tectology of the retina and optic nerve(1)Retinal thickness①The 3^rd day Inner retina(retinal length,RL),nerve fiber layer(nerve fiber layer,NFL),ganglion cell layer(ganglion cell layer,GCL),inner plexiform layer(inner plexiform layer,IPL) and INL (inner nuclear layer,INL):Each group increased,and there was no significant difference in the same layers(P>0.05).②The 1^st weekRL and the IPL:All groups continued to increase,and there was no significant difference in the same layers(P>0.05).NFL:Slightly lower in each group,there was no significant difference in the same layers(P>0.05).GCL:Treatment group and positive control group reduced,and treatment group was significantly lower than model group(P<0.05).INL:Slight increase in each group,treatment group was significantly lower than model group(P<0.05).③The 2^nd weekRL,IPL and INL:All groups continued to increase with no significant difference in the same layers(P>0.05).NFL:All groups decreased with no significant difference whin all groups(P>0.05).GCL:All groups decreased with no difference between treatment group and model group(P>0.05),and positive control group was lower than model group(P<0.05).④The 4^th weekRL,NFL and INL:All groups reduced significantly with no statistic difference whin all groups(P>0.05).GCL:All groups reduced,and treatment group and positive control group were higher than model group(P<0.05).IPL:All groups reduced significantly,and treatment group was higher than model group,positive control group(P<0.05).(2)Ultrastructure of optic nerve①The 3^rddayModel group and Treatment group:Lamellar separation of myelin can be seen.Membrane collapsed,axis retracted,or capreomycin convexed.The number of axons reduced,and parts of them collapse.The numbers of microfilaments and microtubules were both reduced significantly.The mitochondrions were swelled,crest gap widened,or totally collapsed and disappeared.②The 1^st weekModel group and Treatment group:Lamellar separation of myelin can be seen further expansion than before.Parts of nerve fibers collapsed and formed "onion-like body".The numbers of microtubules and microfilaments further reduced,with disorder,mitochondrial swelling,a decrease in the number.③The 2^nd weekModel group and Treatment group:All continued to add to the above changes.The myelins bacame thiner and dissociated bubbly.There were many macrophages containing myelin debris.Some axons were transparent.The numbers of microtubules and microfilament continued to decline and the mitochondria dissolved and disapped.Glial cell proliferated,and the nuclear concentrated into a block.The majority of Mitochondrias disappeared and the lysosomes swallowed up a large number of myelin debris can be seen.④The 4^th weekModel group:The lamellar structure of myelin repaird and was thiner than normal.Parts of the axon restorated and small of them disappeared.The microtubules,microfilaments and mitochondrias increased.The modality of glial cells was irregular and a large number of glial fibrillary can be seen.Treatment group:The lamellar structure of myelin repaired obviously than model group.A large number of axons gradually restored,the electron density increased.Treat group was significantly more than treat group in the numbers of microtubule, microfilament.The mitochondria structure were clear.The glial cells were almost normal and a large number of glial fibrillary in the cytoplasm can be seen.3.The effects of Xuefu Zhuyu Decoction on the microenvironment of optic nerve restoration(1) The expression of GAP-43 in the retina and optic nerve①Normal retina:The expression was weak,and mainly concentrated in the GCL. Normal optic nerve:the expression is weak.②The 3^rd day:Retina and Optic Nerve:The expression of all groups increased obviously and there was no significant difference whin groups(P>0.05).③The 1^st week:Retina:All groups increased obviously.The AOD of treat group was higher than model group,positive control group obviously(P<0.05).Optic Nerve:Model group decreased,treatment group and positive control group increased.Their IOD were obviously higher than model group(P<0.05),and there was no significant difference between them(P>0.05). ④The 2^nd week:Retina:The expression of every group decreased.The AOD of treatment group was lower than positive contol group(P<0.05),and there was no significant difference between treat group and model group(P>0.05).Optic nerve:Model group decreased, treatment group and positive contol group increased with no significant difference between them(P>0.05).But their were both higher than model group(P<0.05).⑤The 4^th week:Retina:The expression in all groups decreased.Treatment group was higher than model group(P<0.05).Optic nerve:The expression in all groups decreased,and there was no statistic difference whin all groups(P>0.05).(2)The expression of ROCKⅡin the retina and optic nerve①Normal retina:The expression was weak,and mainly concentrated in the GCLand ipl. Normal optic nerve:The expression was weak.②The 3^rd day:Retina:The expression of model group and positive control group increased.Treat group decreased.Optic Nerve:All groups increased obviously,The IOD of treat group was lower than model group(P0.05).③The 1^st,2^nd week:The expression of all groups decreased and there was no diference whin groups(P>0.05).Optic nerve:Treat group was obviously lower than model and positive control group(P<0.05).④The 4^th week:Retina:All groups increased.Treat group was lower than model group.Optic nerve:All groups increased.Treat group was lower than model group and positive group(P<0.05).Conclusion1.Xuefuzhuyu Decoction can increase the survival ratio of RGCs significantly.It can be used to treat traumatic optic neuropathies.2.Xuefuzhuyu Decoction can prevent retinal tissue edema and atrophy,and protect the microstructures of optic nerve,which is valuable for restorating the transportation of axonal plasm.3.The retina and optic nerve can self-repair by regulating the expression level of GAP-43 and ROCKⅡ.Xuefuzhuyu Decoction can increase the expression of GAP-43 and decrease the expression of ROCKⅡ.4.Xuefuzhuyu Decoction can treat TON efficiently by improving the survival ratio of RGCs,maintaining or building the structures,accelerating transportation of axonal plasm,and improving the microenvironment for optic nerve fiber to survive or regenerate.