y and regularly with occasional small cracks, myelin staining was uniform with small air bubbles, and a small number of new capillaries were identified under the microscope. In the MSCs + RSV group, sciatic nerve fibers were densely aligned in a row, the vacuolar degeneration of myelin was decreased and new capillaries were observed under microscope, which were increased compared with those in the MSCs group.

### NF-κB, NGF and MBP

The present study examined the levels of the P56 subunit of NF-κB, NGF and MBP to evaluate the inflammation and recovery of the sciatic nerve on day 56. The level of NF-κB in the diabetic control group was significantly increased, while levels of NGF and MBP were decreased compared with the normal control group (P\<0.05, [Fig. 3A](#f3-etm-0-0-7383){ref-type="fig"}). Notably, levels of NF-κB in the insulin group, RSV, MSCs and MSCs + RSV groups were significantly decreased compared with the diabetic control group (P=0.041, P=0.015, P=0.034 and P=0.01, respectively). This indicated that MSCs, insulin and RSV all could improve nerve inflammation in diabetic mice. Following therapy, levels of NGF in the MSCs group and MSCs + RSV group were significantly increased compared with the insulin, RSV and diabetic control groups, yet were significantly decreased compared with the normal control group (P\<0.05). No statistically significant differences were identified between the diabetic control, insulin and RSV groups. Levels of MBP in the insulin group and diabetic control group were lower than the normal control group, RSV group, MSCs group and MSCs + RSV group, as illustrated in [Fig. 3C](#f3-etm-0-0-7383){ref-type="fig"}. No statistical differences were observed between the levels of MBP in the insulin group and the diabetic control group. There were no significant differences in levels of MBP between the normal control group, MSCs group, RSV group and MSCs + RSV group. Taken together, these data suggested that MSCs and RSV relieved inflammation of the sciatic nerve, and that MSCs may s