Evaluation of the therapeutic potential of Curcumin and Methylprednisolone in mental nerve injury: a histological and immunohistochemical study in rats

This study aimed to evaluate the roles of Curcumin and Methylprednisolone on S100 protein and Beta-3 expression levels in healing process of the mental nerve injury. 30 adult Wistar rats were included which were 3 months old and had a body weight of 200 to 250 g. Rats were divided randomly into 3 groups. The left mental nerve of each rat was surgically exposed under sterile conditions. Pressure was applied for 60 s using Yaşargil aneurysm clips, which are commonly used in experimental models due to their consistent and precise pressure application. Group 1 was the control which did not receive any treatment. Rats in the Group 2 were administered 100 mg/kg Curcuma Longa extract; in Group 3 subjects received 2 mg/kg Methylprednisolone intraperitoneally every day for 14 days. After the one-month recovery period, sacrification procedure was performed for histopathological and immunohistochemical evaluation. Mental nerve regeneration was assessed using Beta-3, S-100ß, and Hematoxylin and Eosin parameters. Comparative analyses were conducted using non-parametric statistical methods such as the Kruskal-Wallis and Mann-Whitney U tests. Both curcumin and methylprednisolone significantly increased Beta-3 Tubulin levels compared to the control group (p < 0.05). However, no significant difference was observed between the two treatment groups, suggesting that curcumin and methylprednisolone have comparable effects on nerve regeneration, as indicated by the upregulation of Beta-3 Tubulin, a marker associated with neuronal repair and growth. Immunohistochemical findings reveal that curcumin has a strong effect on S100β expression (p < 0,0001), potentially more pronounced than methylprednisolone. Regarding the clinical significance of the observed S100β upregulation by curcumin, this finding suggests a potential neuroprotective effect. Mental nerve injury is a frequent complication of oral and maxillofacial surgery, and its management and prognosis pose significant clinical challenges. This study highlights the potential of curcumin as an effective therapeutic agent for promoting peripheral nerve regeneration and functional recovery, offering promising implications for the treatment of nerve injuries.