The histopathological and electrophysiological effects of thymoquinone and methylprednisolone in a rabbit traumatic facial nerve paralysis model.
OBJECTIVE
We aimed to determine the effects of methylprednisolone and thymoquinone on nerve healing in a traumatic facial nerve paralysis animal model.


METHODS
Twenty-four rabbits were randomly divided into 4 groups: group I: control group received no medication and no trauma; group II: sham group received no medication after facial nerve trauma group III: 5mg/kg/day thymoquinone administered; group IV: 1mg/kg/day methylprednisolone administered. An initial electrophysiological assessment was performed in all the animals. The buccal branch of the facial nerve was then clipped to form a traumatic facial paralysis model. The drugs were administered for two weeks once a day. At the end of the second month, the electrophysiological assessments were performed and the distal part of the traumatic facial nerve were dissected and examined under light microscopy.


RESULTS
Best nerve regeneration was observed in the control and the thymoquinone groups, respectively, whereas the weakest regeneration was determined in the sham group. Thymoquinone and methylprednisolone significantly increased nerve recovery, as measured by histopathological scores and electrophysiological assessment. In the thymoquinone group, due to postoperative amplitude, axon diameter and thickness of myelin sheath values were significantly further increased nerve regeneration compared to that of the methylprednisolone group and these values were close to those of the values of the control group.


CONCLUSIONS
Thymoquinone was slightly better than methylprednisolone for functional nerve recovery. The neuroprotective effect of thymoquinone was attributed to its antioxidant and anti-inflammatory effects. Thymoquinone can have a new treatment option to ameliorate the nerve injury.
Department of Otolaryngology, Abant Izzet Baysal University, Faculty of Medicine, Bolu, Turkey. Electronic address: srflcn@yahoo.com.
Murat
M
Sereflican
Department of Otolaryngology, Abant Izzet Baysal University, Faculty of Medicine, Bolu, Turkey.
Veysel
V
Yurttas
Department of Pathology, Abant Izzet Baysal University, Faculty of Medicine, Bolu, Turkey.
Gulzade
G
Ozyalvacli
Department of Medical Histology and Embryology, Abant Izzet Baysal University, Faculty of Medicine, Bolu, Turkey.
Elcin Hakan
EH
Terzi
Department of Neurology, Abant Izzet Baysal University, Faculty of Medicine, Bolu, Turkey.
Sule Aydin
SA
Turkoglu
Department of Neurology, Abant Izzet Baysal University, Faculty of Medicine, Bolu, Turkey.
Serpil
S
Yildiz
Department of Medical Histology and Embryology, Gulhane Military Medical Academy, Ankara, Turkey.
Yasin
Y
Ilgaz
Department of Otolaryngology, Abant Izzet Baysal University, Faculty of Medicine, Bolu, Turkey.
Sinan
S
Seyhan
Department of Otolaryngology, Abant Izzet Baysal University, Faculty of Medicine, Bolu, Turkey.
Mesut
M
Oral
Department of Otolaryngology, Abant Izzet Baysal University, Faculty of Medicine, Bolu, Turkey.
Muharrem
M
Dagli
D000818:Animals; D016227:Benzoquinones / Q000627:therapeutic use*; D004195:Disease Models, Animal; D004576:Electromyography; D020220:Facial Nerve Injuries / Q000150:complications* / Q000473:pathology / Q000503:physiopathology; D005158:Facial Paralysis / Q000188:drug therapy* / Q000209:etiology / Q000473:pathology; D008297:Male; D008775:Methylprednisolone / Q000627:therapeutic use*; D009416:Nerve Regeneration; D018696:Neuroprotective Agents / Q000627:therapeutic use*; D011817:Rabbits; D020127:Recovery of Function
D016227:Benzoquinones; D018696:Neuroprotective Agents; C003466:thymoquinone; D008775:Methylprednisolone