Evaluation of the Regeneration Effects of Systemically Applied Methylprednisolone and Vitamin B12 on Mental Nerve Crush Injury.

Abstract

To evaluate the effects of methylprednisolone and vitamin B12 injection on the regeneration of the nerves after a mental nerve crush injury. A total of 40 albino Wistar rats have been randomly divided into four groups: group 1 (n=10): crushlike nerve damage was created by pinching the left mental nerve for 60 s with an aneurysm clip and intraperitoneally administered 1 ml of saline for 14 days; group 2 (n=10): the left mental nerve was pinched for 60 s with an aneurysm clip and intraperitoneally administered 2 mg/kg of methylprednisolone for 14 days; group 3, experimental group (n=10): the left mental nerve was pinched for 60 s with an aneurysm clip and intraperitoneally administered 2 mg/kg of vitamin B12 for 14 days; and group 4, experimental group (n=10): the left mental nerve was pinched for 60 s and intraperitoneally administered 2 mg/kg of methylprednisolone and 2 mg/kg of vitamin B12 for 14 days. All rats were sacrificed on the 28th postoperative day, and histopathological evaluation was performed. Nerve damage was higher in the control group than in other groups (p < 0.05). When Neural Cell Adhesion Molecule (NCAM) expression levels were compared, no major differences were observed between the methylprednisolone and control groups (p > 0.05). The B12 and B12+methylprednisolone groups reached significantly higher NCAM expression levels compared to the control and methylprednisolone groups. When the myelin basic protein (MBP) expression levels were compared (p < 0.05), the MBP expression was significantly higher in all experimental groups than in the control group (p < 0.05). Systemic vitamin B12 and methylprednisolone administration effectively supported remyelination in the crushed mental nerve by increasing Schwann cell proliferation and differentiation.