The comparative effects of estrogen and tacrolimus on crushed sciatic nerve regeneration in male mice: functional and histological evaluation

Some pharmacological agents can be effective for peripheral nerve injuries treatments. Present study aimed to apply different agents and compare the nerve regenerative effects following crushed sciatic nerve injuries. Twenty four (n=24) adult male mice were conducted in this study. Standard unilateral left side sciatic nerve crush was performed with 2 mm width mosquito hemostat forceps. The mice were randomly divided into 4 groups with the same numbers in each group which received subcutaneously, estrogen (group I), tacrolimus (group II), the combination of estrogen and tacrolimus (group III), and saline 0.9%. Functional recovery, histopathology, and Immunohistochemistry (IHC), were assessed on days 14th and 28th. Walking track analysis on day 14th showed no significant difference between experimental groups (P>0.05) but they showed significant difference compared to the control group (P<0.05). At the same time, experimental groups showed similar results of inflammatory cell infiltration, axonal edema, and count with significant differences between the control (P<0.05). At the end of the study, group I and III showed a significant difference in functional recovery between group II and control (P<0.05). After fourth week significant histopathological difference of axonal count was observed in group III (P<0.05). On day 28th, only IHC assessment in group III increased more Glial fibrillary acidic protein (GFAP) expression compared with the same group on day 14th. This study revealed subcutaneous administration of combined estrogen and tacrolimus can be effective with acceptable results in nerve regeneration.