Efek Pemberian Curcumin terhadap Fungsi Pendengaran pada Pekerja dengan Gangguan Pendengaran Akibat Bising Ditinjau dari Pemeriksaan Audiometri Nada Murni, Otoacoustic Emission (OAE), dan Kadar Heat Shock Protein 70 (HSP70) dalam Darah

Abstract

Introduction: Exposure to high-intensity acoustic stimuli can induce sensorineural hearing loss owing to oxidative stress in the cochlea. As a protective mechanism, the cochlea requires a cytoprotective response in the form of the expression of Heat Shock Protein 70 (HSP70), which has been identified as an otoprotective agent. Curcumin has been demonstrated to enhance antioxidant expression and is effective in preventing and treating damage to the lateral wall fibroblasts of the cochlea. Pure tone audiometry can determine the type and degree of hearing impairment, whereas otoacoustic emission (OAE) can detect early stage auditory disorders. Objective: To assess the effects of curcumin on noise-exposed workers using pure tone audiometry, OAE, and blood levels of HSP70. Methods: This experimental study was conducted in an iron factory in Medan City with a noise intensity of 105 dB. Workers were examined using pure tone audiometry and OAE, 42 workers were obtained who met the inclusion criteria. The samples were divided into 3 groups, namely group 1 as control, group 2 received Curcumin 500 mg, and group 3 received Curcumin 1,000 mg for 4 weeks. Blood was collected before and after treatment to determine HSP70 levels. Pure tone audiometry and OAE examinations were repeated after treatment. Results: Based on pure tone audiometry, there was a worsening of hearing threshold in the control group (p<0.001), while in the curcumin 500 mg group, there was an insignificant improvement in hearing threshold (p=0.189), in the Curcumin 1,000 mg group there was no significant change in hearing threshold (p=0.317). In the OAE examination, there was a significant decrease in the SNR before and after treatment in the control group (p<0.001). In the Curcumin 500 mg group, there was an increase in SNR values at frequencies of 3, 4, 5, 7, 8, and 9 kHz. In the Curcumin 1,000 mg group, there was an increase in SNR values at frequencies of 4, 5, 7, 8, and 9 kHz. From the examination of HSP70 levels, there was a significant increase in levels (p=0.004) in the control group, a non-significant increase in HSP70 levels (p=0.544) in the Curcumin 500 mg group, a non-significant increase in HSP70 levels (p=0.265) in the Curcumin 1,000 mg group. Conclusion: Curcumin can prevent further decline in hearing function as indicated by an improvement in hearing threshold in the Curcumin 500 mg group compared to the positive control group from pure tone audiometry examination. Curcumin can also prevent further decline in hearing function, as indicated by an increase in SNR at several frequencies and a non-significant decrease in SNR in the 500 mg and 1,000 mg groups compared to the control group. Curcumin also prevented the increase in HSP70 levels compared to that in the control group. Keywords: Curcumin, Noise, Heat shock protein 70, Pure Tone Audiometry, Otoacoustic emission