Effects of Purendan superfine powder on retinal neuron apoptosis and expression of apoptosis-associated genes in diabetic rat

AIM:To investigate the effects of Purendan superfine powder(PRD) on apoptosis of retinal neurons and expression of apoptosis-associated genes in diabetic rats.METHODS: Thirty-six male Wistar rats were randomly divided into 3 groups(n=12): normal control group,diabetes model group and PRD treatment group.The rat model of diabetes was made by continuous intraperitoneal injection of streptozotocin(STZ).After successfully established the diabetes animal model,the rats in PRD treatment group were lavaged with PRD for 3 months.Neuronal apoptosis in retina was detected by TdT-mediated dUTP nick end labeling(TUNEL).Immunohistochemical staining was used to assess Bcl-2,Bax and caspase-3 protein expression in retina.Reverse transcription-polymerase chain reaction(RT-PCR) was used to assess the mRNA expression of Bcl-2,bax and caspase-3 in retina.RESULTS: Apoptotic index of retina,the protein and mRNA expression of Bax and caspase-3 in retina were obviously higher in diabetic rats than those in normal control rats(P0.01).The mRNA and protein expression of Bcl-2,the ratio of Bcl-2/Bax were significantly lower in diabetic rats than those in normal control rats(P0.01).Apoptosis index of retina,the mRNA and protein expressions of bax and caspase-3 in retina were significantly lower in PRD treatment group than those in diabeic rats(P0.01).The mRNA and protein expression of Bcl-2,the ratio of Bcl-2/Bax were obviously higher in PRD treatment group than those in diabetic rats(P0.01).CONCLUSION: PRD inhibits neuronal apoptosis by up-regulating Bcl-2 expression and down-regulating Bax and caspase-3 expression in retina of diabetic rats,then has protective effects on diabetic retinopathy.