Study On The Protective Effects Of Toona Sinensis Leaf Extract On The Retina Of Hyperlipidemia Rats

PurposeTo explore the model of hyperlipidemia rat retinal damage and AMD and determine whether the TSLE have protective effects on the retina damaged by high fat,and investigate its protective mechanism,providing potential new treatments for the occurrence and development of early AMD.MethodsA total of 24 healthy male SD rats(48 eyes)were selected for 10-12 weeks.They were randomly divided into normal group(N),high-fat diet group(HF),high-fat diet + Toona sinensis leaf extract group(HF+TSLE).The rats in group HF and group HF+TSLE were fed with high fat diet(10ml/kg/day),and group N was fed with the same dose of physiological saline.After 8 weeks,fasting blood lipids were detected.After the success of the model,the rats in group HF+TSLE were fed with TSLE solution for 4 weeks(1g/kg/day).Meanwhile,the rats in group N and HF were given the same dose of normal saline by gavage.After 12 weeks,all rats were examined of ocular visual function and fundus retina imaging,and the blood lipid and liver index;the eyes of each group were taken paraffin embedded hematoxylin eosin staining to observe the morphological changes of retinal tissue;Immunohistochemical method was used to locate and quantify apoptotic factor caspase-3 and inflammatory factor IL-6,TNF-a /NF-?BP65 protein.Western Blot was used to detect the expression level of each protein and to explore the protective mechanism of TSLE.ResultsAfter induction of high-fat diet,the contents of TC,TG and LDL-C in serum of HF group increased compared with those in N group,while the content of HDL-C decreased.After TSLE treatment,the TC,TG and LDL-C contents in HF+TSLE group were lower than those in group A.FERG test results showed that the retinal function of light conversion dysfunction group HF outer retina photoreceptor cells,showed the latency of a prolonged,TSLE after the intervention,the latency time was significantly shorter,and there was no significant difference in B latency change;group HF a wave amplitude of B wave decreased compared with the normal group,extract from Toona sinensis leaves after treatment,no amplitude may be increased,long experimental cycle and reduced visual function with age in rats.The results of fundus photography showed that there was no obvious change in retina fundus in HF group,and no lipid deposition and exudate was found.HE staining showed: normal rat retinal cells arranged normal rules,cells arranged in disorder of retinal tissue in HF rats and apoptosis in different degree,especially the number of outer nuclear layer photoreceptor cells decreased,arranged in disorder,all retinal thickness becomes thinner;after TSLE treatment,the retinal tissue damage obviously.The results of immunohistochemistry and westerblotting showed that the expression of Caspase-3,IL-6,TNF-a /NF-?BP65 was negatively correlated with TSLE.Correlation analysis showed that the expression level of Caspase-3 was positively correlated with the latency of a wave(r=0.583,P=0.046),and positively correlated with the latency of B wave(r=0.596,P=0.042),which was not correlated with the amplitude of a wave and b wave(P>0.05).Conclusions 1.Toona sinensis leaf extract can inhibit the expression of IL-6 and TNF-?/NF-?Bp65/caspase3 during the retinal injury of hyperlipidemia model rats,suggesting that it can protect the retinal tissue apoptosis by inhibiting the apoptosis of retina tissue.2.Toona sinensis leaf extract can inhibit retinal damage caused by abnormal lipid metabolism,and provide a new direction for further search for effective prevention or treatment of AMD.