The protective role of tetramethylpyrazine against cisplatin-induced ototoxicity.
OBJECTIVE
The aim of the present study was to investigate the protective effect of tetramethylpyrazine (TMP) on cisplatin-induced ototoxicity in rats.


METHODS
Forty healthy, female, 24-week-old, Sprague-Dawley rats (n = 40) were randomly assigned to four groups as follows: group one (n = 10) received intraperitoneal (i.p.) physiological saline at daily doses of 3 mg/kg for seven days; group two (n = 10) received a single dose of i.p. 15 mg/kg cisplatin; group three (n = 10) received i.p. 140 mg/kg TMP daily for seven days plus a single dose of i.p. 15 mg/kg cisplatin on the fourth day; group four (n = 10) received i.p. 140 mg/kg TMP daily for seven days. Auditory brainstem response (ABR) and distortion product otoacoustic emission (DPOAE) measurements were obtained from the animals (40 rats, 80 ears) under general anesthesia before and after drug administration. The temporal bulla of animals were bilaterally removed for immunohistopathological examination.


RESULTS
In group two, DPOAE and ABR values were significantly deteriorated after drug administration, whereas there was no statistically significant difference between the pre- and posttreatment DPOAE and ABR values for all frequencies for groups one, three and four. The mean scores for external ciliated cells (ECCs), stria vascularis (SV) and spiral ganglion (SG) injuries in hematoxylin and eosin (H&E) staining, and also caspase-3 immunoreactivity were significantly higher in group two than in the other groups.


CONCLUSIONS
In the present study, the protective effect of TMP on cisplatin ototoxicity was demonstrated through studies of electrophysiology and immunohistopathology. Co-administration of TMP may have potential protective effects against cisplatin-induced ototoxicity.
Department of ENT, Kayseri Training and Research Hospital, Kayseri, Turkey. Electronic address: dralibayram@gmail.com.
Ali
A
Bayram
Department of ENT, Kayseri Training and Research Hospital, Kayseri, Turkey.
Altan
A
Kaya
Department of Pathology, Kayseri Training and Research Hospital, Kayseri, Turkey.
Ebru
E
Akay
Department of ENT, Kayseri Training and Research Hospital, Kayseri, Turkey.
İbrahim
İ
Hıra
Department of ENT, Kayseri Training and Research Hospital, Kayseri, Turkey.
İbrahim
İ
Özcan
D000818:Animals; D000970:Antineoplastic Agents / Q000009:adverse effects*; D053148:Caspase 3 / Q000032:analysis; D002945:Cisplatin / Q000009:adverse effects*; D004427:Ear Diseases / Q000139:chemically induced* / Q000503:physiopathology / Q000517:prevention & control*; D016057:Evoked Potentials, Auditory, Brain Stem; D005260:Female; D017084:Otoacoustic Emissions, Spontaneous; D011719:Pyrazines / Q000627:therapeutic use*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013136:Spiral Ganglion / Q000737:chemistry / Q000473:pathology; D013316:Stria Vascularis / Q000737:chemistry / Q000473:pathology; D014665:Vasodilator Agents / Q000627:therapeutic use*
D000970:Antineoplastic Agents; D011719:Pyrazines; D014665:Vasodilator Agents; D053148:Caspase 3; D002945:Cisplatin; C017953:tetramethylpyrazine
Cisplatin; Ototoxicity; Tetramethylpyrazine