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

Noise Health. 2018 Nov-Dec;20(97):232-239. doi: 10.4103/nah.NAH_33_18.


Objective: 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.

Materials and methods: 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.

Results: 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.

Conclusion: 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.

Keywords: Diallyl disulfide; S-allylmercaptocysteine; garlic extracts; noise-induced hearing loss; oxidation; vitamin B12.

MeSH terms

  • Allyl Compounds / therapeutic use*
  • Animals
  • Antioxidants / therapeutic use*
  • Cysteine / analogs & derivatives*
  • Cysteine / therapeutic use
  • Disulfides / therapeutic use*
  • Evoked Potentials, Auditory, Brain Stem / drug effects
  • Garlic / chemistry
  • Hearing Loss, Noise-Induced / drug therapy*
  • Noise / adverse effects
  • Plant Extracts / therapeutic use*
  • Rats
  • Vitamin B 12 / therapeutic use*


  • Allyl Compounds
  • Antioxidants
  • Disulfides
  • Plant Extracts
  • S-allylmercaptocysteine
  • diallyl disulfide
  • Cysteine
  • Vitamin B 12