Neuroprotective Effect of Melatonin on Experimental Peripheral Nerve Injury: An Electron Microscopic and Biochemical Study

Abstract

Background and Study Aims: Melatonin is an important antioxidant agent with a protective role in the prevention of oxidative stress. We designed an experimental study which focused on the potential neuroprotective effect of melatonin on peripheral nerve injury.

Materials and Methods: Sciatic nerve injury was induced in the mid thigh region of 30 male Wistar rats by clip compression. Melantonin was injected intraperitoneally in 15 of the 30 rats. Electron microscope and biochemical studies were performed to assess the potential beneficial effect of melatonin on peripheral nerve regeneration. Changes to cellular organelles, myelin lamellae and axons were studied.

Results: There was a significant difference between the melatonin and nerve injury groups. Rats treated with melatonin demonstrated significant structural protection of the myelin lamellae compared to the nerve injury group. Axonal shrinkage and myelin changes were not prominent histopathologically in melatonin-treated group. Biochemical analysis confirmed the neuroprotective effects of melatonin with significantly lower lipid peroxidation and myeloperoxidase activity measurements in the melatonin-treated group compared to the neural injury group. The results indicate that melatonin can improve neural healing.

Conclusion: With its neuroprotective effect, as demonstrated in this experimental peripheral nerve injury, melatonin might be used successfully in clinical practice. Further studies on the correct dosage and possible side effects are necessary.

Zusammenfassung

Hintergrund und Zielsetzung: Melatonin ist ein wichtiges Antioxidans, welches in der Lage ist, Zellelemente vor oxidativem Stress zu schützen. Wir haben in einer experimentellen Studie die potentiell neuroprotektive Rolle von Melatonin nach Verletzung peripherer Nerven untersucht.

Material und Methoden: Bei 30 Ratten erfolgte durch die Applikation eines Clips die Verletzung des N. ischiadicus im mittleren Oberschenkelbereich. 15 der 30 Ratten erhielten Melatonin intraperitoneal. Mittels Elektronenmikroskopie und biochemischer Untersuchungen zur Erfassung von Veränderungen der Zellorganellen, der Myelinschichten und der Axone wurde untersucht, ob Melatonin gegebenenfalls einen positiven Effekt auf die Regeneration der peripheren Nerven hat.

Ergebnisse: Es zeigten sich signifikante Unterschiede zwischen der Melatonin-Gruppe und der Gruppe, welche kein Melatonin erhalten hatte. Histopathologisch waren Axon-Schrumpfung und Myelinveränderungen in der Melatonin-Gruppe weniger ausgeprägt als in der Gruppe der unbehandelten Tiere. Biochemische Analysen zeigen eine niedrigere Lipid-Peroxidation und Myeloperoxidase-Aktivität in der Melatonin-Gruppe.

Zusammenfassung: Bei tierexperimenteller peripherer Nervenverletzung lässt sich biochemisch und histopathologisch ein neuroprotektiver Effekt von Melatonin nachweisen. Eine klinische Studie zur Dosisfindung und Erfassung von Nebenwirkungen sollte überlegt werden.

Key words

melatonin - rat - sciatic nerve injury - electron microscope study - lipid peroxidation

Schlüsselwörter

Melatonin - Ratte - N. ischiadicus-Verletzung - Elektronenmikroskopie - Lipid-Peroxidation

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