Evaluation of Effect of Garlic Aged Extracts and Vitamin B12 on Noise-Induced Hearing Loss.

This study investigated effects of S-allylmercaptocysteine (SAMC), diallyl disulfide (DADS), and vitamin B₁₂ on inner ear functions and morphology after long-period high-level broadband noise exposure.

Twenty-four healthy rats were randomly divided into four groups. First group was chosen as the control group. Vitamin B₁₂, SAMC, and DADS were applied to other groups for 4 weeks. On the 14th day, each group was exposed to broadband noise. Auditory brainstem response test was performed before and immediately after noise exposure and repeated on the 2nd and 14th day.

Permanent threshold shifts were significantly lower in groups treated with vitamin B₁₂, SAMC, and DADS. Histologically, cochleae of SAMC and DADS groups were found to be better preserved than the cochleae of vitamin B₁₂ and control groups.

Physiologically and histologically, SAMC and DADS reduced the long-term effects of noise. However, physiological recovery was not consistent with the morphological findings in vitamin B₁₂ group.