Comparison of melatonin and curcumin effect at the light and dark periods on regeneration of sciatic nerve crush injury in rats

Being one of the acute clinical problems, peripheral nerve injury can bring about a number of consequences in- cluding severe disability, redu ced Quality of life (QOL) and immense costs. Currently, melatonin and curcumin are widely applied because of their immunomodulatory, anti-inflammatory, neuro-protective and antioxidant prop- erties. The present stud y aims to compare the effects of melatonin and curcumin during light and dark periods on sciatic nerve crush injury repair. Acco rdingly, rats received IP injections of curcumin (100 mg/kg) and melatonin (10 mg/kg) over two periods of light (9:00 a.m.) and dark (9 :00 p.m.) for 4 weeks. In order to evaluate rats, func- tional (walking track analysis and electrophysiological measurements), histomorphometric and gastrocnemius muscle mass investigations were administered. No statis tically 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. On the whole, this study found that mela- tonin 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 ra ts were treated by melatonin during the dark period while effects and injection time did not correlate in curcum in application