The Effect of Gingko Biloba (EGB 761) as an Otoprotector Against Cisplatin Ototoxicity

Abstract

Objectives: Evaluate, by using distortion product oto-acoustic emissions (DPOAE) test, the effect of ginkgo biloba extract (EGB761), which has shown antioxidant properties as a possible otoprotector against cisplatin induced hearing loss. Ototoxicity is an alteration caused by drugs that compromises the auditory and vestibular functions. Cisplatin (CDDP) is a potent antineoplastic agent used for the treatment of cancer although it has several side effects like ototoxicity (a dose-limiting condition). Currently, cisplatin ototoxicity occurs due to alterations in the antioxidant system of the outer hair cells (OHC) of the cochlea. Different antioxidant drugs have been tested to evaluate the potential otoprotector effect combined to cisplatin administration. Distortion product otoacoustic emission test (DPOAE) has been showed to be a sensitive test for diagnosis of OHC injury and has been used for monitoring treatment of ototoxic drugs. Methods: The study was conducted on individuals that would begin cisplatin treatment. They were randomized and allocated in two groups: Control group (CG) (n =07) received placebo and CDDP and study group (SG n = 08) received EGB761 (240mg/day) and CDDP. Both groups ingested the drugs before first cisplatin dose. They were treated and followed up for approximately ninety days. Results: The maximum cumulative cisplatin dosage was 300mg/m2. Comparisons were made between baseline measurements and those records after maximum cumulative cisplatin dosage. The CG showed smaller amplitudes of the signal and signal/noise ratio compared to baseline. Conclusions: These results demonstrate that EGB761, because of their antioxidant properties, showed potential otoprotector effect.