Intervention Of Jinmaitong To Oxidative Stress In Dorsal Root Ganglion Of Diabetic Rats

[Objective]The aim of the present study is to investigate the potential curative effects of compound recipe Jinmaitong on diabetic peripheral neuropathy by mechanism of inhibiting oxidative stress. The influence of Jinmaitong on Nissl's bodies in neurons of dorsal root ganglion (DRG) of Streptozotocin-induced diabetic rats were observed, and the expression of NADPH oxidase and inducible NOS in DRG tissues were evaluated.[Methods]Male Spague Dawley rats were used in this study. Diabetes was induced by Streptozotocin (STZ) at a single dose of 60mg/kg by intraperitoneal injection. The rats with blood glucose of tail vein more than 16.7mmol/L were considered diabetics for study.14 healthy SD rats were injected equivalent normal saline intraperitoneally as control group with blood glucose less than 7.0mmol/L. Diabetic rats randomly divided into 5 groups:(1) DM model group with no drugs; (2) Jinmaitong high-dose group (20-fold dose recommened for human); (3) Jinmaitong middle-dose group (10-fold dose recommened for human); (4) Jinmaitong low-dose group (5-fold dose recommened for human); (5)Vitamin C group (10-fold dose recommened for human); each group had 14 rats. Rats in Jinmaitong and Vit C groups were administered intragastically once a day, meanwhile the rats in model and normal groups were given equivalent distilled water. After all rats were executed to death, the dorsal root ganglion (DRG) tissues were isolated and then fabricated to paraffin sections. Nissl's staining was administered and expression of NADPH oxidase p22phox, inducible nitric oxide synthase (iNOS) was detected by immunohistochemical methods.[Results]1. Nissl's stainingNissl's bodies depleted visiblely and the staining faded in DRG neurons of rats in model group. In Jinmaitong high-dose and middle-dose groups, the morphologic abnormality of Nissl's bodies in DRG nreuons was slight from that of rats in normal group. In Jinmaitong low-dose ana Vit C groups Nissl's bodies circumnuclear reduced obviously and some occurred vacuolated changes, but these changes in morphology were less severe than that in model group. 2. Expression of NADPH oxidase p22phox submit in DRG tissueExpression of p22phox existed in DRG tissues of DM rats. Compared to normal group, integral optical density (IOD) value of other 5 groups elevated significantly (p<0.0.1); IOD of Jinmaitong high-dose group (10.48+2.70) accessed to that of normal group (6.17±1.86) (p>0.05). Compared to model group, IOD of Jinmaitong groups lowered very significantly (p<0.01), while IOD of Vit C group was lower(p<0.05). IOD of Jinmaitong groups with high, middle, low dose were lower than that of Vit C group respectively (p<0.01, p<0.01, p<0.05).3. Expression of iNOS in DRG tissueExpression of iNOS existed in DRG tissues of DM rats. Compared to normal group, IOD of Jinmaitong with all dose groups, Vit C group, model group all elevated significantly (p<0.01). IOD of Jinmaitong with all dose groups and Vit C group was lower than that of model group (p<0.01). There is no significant difference between Jinmaitong low-dose and Vit C group (p>0.05). IOD of Jinmaitong high-dose and middle-dose group was lower than that of Vit C group respectively (p<0.01, p<0.05).[Conclusions]1. Expression of NADPH oxidase p22phox submit and inducible nitric oxide synthase (iNOS) exits in DRG tissues of DPN rats; and compared to normal rats, the expression of them increases significantly. Obvious oxidative-nitrosative stress occurs in peripheral sensory nerve tissues of DPN rats.2. Jinmaitong can alleviate loss of Nissl's bodies and morphologic abnormality which indicates that DRG neurons injury can be relieved.3. Jinmaitong can decrease the expression of NADPH oxidase p22phox submit and iNOS in DRG of DPN rats. That effect seems to be superior to Vit C treatment.4. The present study givens evidence that oxidative stress exists in peripheral sensory nerve system of DM rats. Jinmaitong can alleviate injury of nerve tissue due to counteracting oxidative stress. Jinmaitong has potential effects on inhibiting the development of DPN.