Evaluation of the Relationship Between the Light/Dark Cycle and Neuropractive Properties of Melatonin and Curcumin in a Rat Nerve Injury Model

Background and Objective: Being one of the acute clinical problems, peripheral nerve injury can bring about a number of consequences including severe disability, reduced Quality of life (QOL) and immense costs. Currently, melatonin and curcumin are widely applied because of their immunomodulatory, anti-inflammatory, neuro-protective and antioxidant properties. The present study aims to compare the effects of melatonin and curcumin during light and dark periods on sciatic nerve crush injury repair(۱-۴). Materials and Methods: This study involved fifty-six male Wistar rats weighing between ۲۵۰–۳۰۰ g. Rats were randomly assigned to seven groups (n=۸): Sham (control), curcumin during dark period (D Cur), Vehicle (DMSO), curcumin during light period (L Cur), melatonin during light period (L Mel), crush (injury without any intervention), and melatonin during dark period (D Mel). Rats received IP injections of curcumin (۱۰۰ mg/kg) and melatonin (۱۰ mg/kg) over two periods of light (۹:۰۰ a.m.) and dark (۹:۰۰ p.m.) for ۴ weeks. In order to evaluate rats, functional (walking track analysis and electrophysiological measurements), histomorphometric (Hematoxylin-Eosin (H&E), Luxol Fast Blue (LFB) and Immunohistochemical (IHC) staining), gastrocnemius muscle mass and Total Oxidant Status (TOS) investigations were administered(۵, ۶). Findings: No statistically significant difference was identified between dark and light curcumin groups while curcumin groups displayed better results than did melatonin groups. In addition, dark melatonin group displayed better results than the light melatonin. Conclusion: On the whole, this study found that melatonin and curcumin can be used to quicken neural recovery and help treat nerve injury. It was also found that better neuroregeneration or nerve regeneration was induced when rats were treated by melatonin during the dark period while effects and injection time did not correlate in curcumin application.

کلیدواژه ها:

Melatonin ، curcumin ، nerve injury ، anti-inflammatory ، antioxidant ، crush