Curcumin Reduces the Noise-Exposed Cochlear Fibroblasts Apoptosis

ABSTRACT

Abstract Introduction The structural changes underlying permanent noise-induced hearing loss (NIHL) include loss of the sensory hair cells, damage to their stereocilia, and supporting tissues within the cochlear lateral wall. Objective The objective of this study is to demonstrate curcumin as a safe and effective therapeutic agent in the prevention and treatment for fibroblasts damage within the cochlear supporting tissues and lateral wall through cell death pathway. Methods We divided 24 Rattus norvegicus into 4 groups, Group 1 control; Group 2 noise (þ); Group 3 noise (þ), 50 mg/day curcumin (þ); Group 4 noise (þ), 100 mg/day curcumin (þ). We provided the noise exposure dose at 100 dB SPL for two hours over two weeks and administered the curcumin orally over two weeks. We examined all samples for the expressions of calcineurin, nuclear factor of activated T-cells cytoplasmic 1 (NFATc1), and apoptotic index of cochlear fibroblasts. Results We found significant differences for the expressions of calcineurin (p< 0.05) in all groups, significant differences for the expressions of NFATc1 (p< 0.05) in all groups, except in Groups 1 and 4, and significant differences for the apoptotic index (p< 0.05) in all groups. Conclusion Curcumin proved to be potentially effective in the prevention and treatment for fibroblasts damage within the cochlear supporting tissues and lateral wall regarding the decreased expression of calcineurin, NFATc1, and apoptotic index of cochlear fibroblasts.