| Purpose:To investigate the effects of diosgenin extracted from Dioscorea nipponica on the histomorphology of sciatic nerve and the expression of nuclear transfer factors NF-k B and Ik Ba in rats with painful diabetic peripheral neuropathy.Material and method:A total of 136 male Wistar rats were selected,and their weight was 180-200 g,and they were randomly divided into five groups: normal control group,model group,diosgenin high dose group,diosgenin low dose group and prednisone group,each group of 24.The molds were made by injecting 2 percent of Streptozotocin(STZ)53mg/kg(0.1mol/l citric acid buffer)in the abdominal cavity.Observed for 2 weeks,4 weeks,8 weeks after rat behavior characteristics,blood glucose,body weight,nerve conduction velocity,the change of pain threshold condition.The histomorphology of rat sciatic nerve was observed by optical microscope,and the expression of nuclear transfer factor NF-k B and Ik Ba in rat sciatic nerve was detected by immunohistochemical method.Results:1.The model group rats mental state is poor,more drinks,polyphagia,polyuria,color dark yellow without luster,nuzzles camber,etc.,to medicine group status is better than that of model group rats,the yam saponins in high dose group and prednisone group rats condition improved significantly.2.The blood glucose level of rats in the control group was significantly lower than that in the model group and the control group(P < 0.01).In 4 weeks and 8 weeks,the blood glucose level of rats in each group was lower than that in the model group(P>0.05).The blood glucose levels of diosgenin in the high-dose group and the prednisone group were significantly lower than those in the model group at 12 weeks(P < 0.05).3.The model group and each dosage group compared with normal control group rats significantly reduce weight level(P < 0.01),with the extension of course,the model group and each group of slow weight gain in rats,the dose group compared with model group no difference between the weight of rats.4.The nerve conduction velocity(MNCV)of was the control group significantly faster than that in the model group and each drug group(P<0.01).With the extension of the course of disease,the nerve conduction velocity in the model group decreased.The nerve conduction velocity(MNCV)of diosgenin in high,low dose group and prednisone group was increased in 4 weeks(P<0.05);The nerve conduction velocity(MNCV)of diosgenin in high and low dose group was increased in 8 weeks(P<0.01),The nerve conduction velocity(MNCV)of rats in the prednisolone group was increased(P<0.05);The nerve conduction velocity(MNCV)of diosgenin in high,low dose group and prednisone group was increased in 12 weeks(P < 0.01).5.The pain threshold of rats in the model group and each group was significantly higher than that in the normal group(P<0.01).The pain threshold of rats was significantly lower than that in the model group(P<0.01).Compared with low dose group,high dose group of pain threshold of rats decreased significantly(P < 0.01),4 weeks,8 weeks prednisone group rats pain threshold condition significantly increased(P < 0.01),and 12 weeks prednisone group of pain threshold of rats showed a trend of increase(P > 0.05);The pain threshold of rats in the prednisolone group was significantly lower than that in the low dose group(P<0.01).6.Normal group: After 2W,4W and 8W,the sciatic nerve myelinated nerves were arranged in parallel bundles,uniform and orderly,and the fibers were closely connected.The axons(purple red)were visible in the middle of each nerve,and the myelin sheath formed by the axons surrounding Schwann cells(uniform pink).The myelin sheath was thick and uniform.The long round Schwann cell nucleus(blue)was visible close to the nerve myelin sheath.In model group,the arrangement of myelinated nerve fibers was disordered,irregular in shape,unclear in structure,decreased in number,swelled in part,enlarged in nerve fibers gap,and dissolved,thinned or even disappeared in part.This change became more and more obvious with the prolongation of the course of disease,and became more obvious in 2 < 4 < 8 weeks.Two weeks later,there were slight injuries of myelinated nerve fibers(see Fig.4).Four weeks later,the arrangement of myelinated nerve fibers was scattered,some nerve fibers were swollen,the density of myelin sheath was uneven,segmental demyelination and some axonal atrophy became thinner(see Fig.5).Eight weeks later,the arrangement of myelinated fibers became more disordered,the density of myelin sheath became more uneven,segmental demyelination became more obvious,and most axonal atrophy became more obvious.Fine or even disappeared,Schwann cells decreased(see Fig.6 attached).Administration groups:neuropathological changes were also observed in the model group.However,with the time going on,the degree of nerve injury in the high-dose group,the low-dose group and the prednisone group was significantly reduced,the arrangement of nerve cells became dense,the swelling of nerve fibers was alleviated,the thickness of myelin sheath was uniform,the phenomenon of demyelination and dissolution of myelin sheath was reduced,and Schwann’s fine.The nuclei are scattered around the myelin sheath and axons are clearly visible.The improvement of diosgenin high dose group was the most obvious,with the intensity of improvement being 2 < 4 < 8 weeks in turn;the improvement of diosgenin low dose group was the weakest,with the intensity being 2 < 4 < 8 weeks in turn;and the intensity of prednisone group was in the middle,with the intensity being 2 < 4 < 8 weeks in turn.(See Figure 7 attached).7.At 2 weeks,there was no significant difference in the expression of NF-kappa B between the treatment group and the model group(P > 0.05);at 4 and 8 weeks,the expression of NF-kappa B decreased significantly compared with the model group(P< 0.01);meanwhile,there was no significant diffenciation in the expression of NF-kappa B between the treatment groups(P > 0.05).The expression of I-kappa-Ba in the sciatic nerve was weaker in the model group than in the normal group(P < 0.01).The expression intensity of I-kappa-Ba in the model group decreased with the prolongation of the course of the disease;there was no significant difference in the expression of I-kappa-Ba between the treatment group and the model group at 2 weeks(P > 0.05);the expression of I-kappa-Ba was increased in the treatment group and the model group at 4 and 8 weeks(P < 0.01).There was no significant difference in the expression of I-kappa-Ba between the two groups(P > 0.05).Conclusion:Diosgenin from Dioscorea nipponica extract can improve nerve conduction velocity and pain threshold in PDPN rats,protect injured sciatic nerve,delay the process of nerve injury and further alleviate the symptoms of PDPN rats. |
PDF Full Text Request