A review on medicinal plants used for treating ototoxicity and acoustic trauma induced hearing loss

Hearing loss induced by chemotherapy and acoustic trauma is mainly associated with two factors, free radical formation and apoptosis pathway activation. Despite numerous efforts on reducing the effects of these factors, no definite strategy is still determined to interfere with and control these processes. In recent studies, various protective agents, including antioxidants have been used on animal models, to inhibit the formation of free radicals thus improving hearing loss.In this review article we will discuss the role of traditional herbal medicine in treatment of noise/drug induced hearing loss, focusing on medicinal plants' active substances,as well as their mechanisms of action in reducing or preventing the formation of free radicals thus increasing the rate of survival of cochlea cells. Data have been gathered since year 2000, from scientific publications including the following keywords: deafness, drug toxicity, acute trauma, medicinal herbs and oxidative stress. The study includes all herbs and medicinal plants that have been experimentally used in studies on animal models and clinical trials. The results from these studies indicate the effectiveness of most of these herbs and their active substances through their antioxidative properties. Medicinal plants reported in this review can thus be considered as effective remedies intreating noise/drug induced hearing loss,yet further studies need to be done.

Gender and other factors associated with the use of hearing protection devices at work / Gênero e fatores associados ao uso de equipamento de proteção auditiva no trabalho

OBJECTIVE To analyze whether sociodemographic, occupational, and health-related data are associated with the use of hearing protection devices at work, according to gender. METHODS A cross-sectional study was conducted in 2006, using a random sample of 2,429 workers, aged between 18 and 65 years old, from residential sub-areas in Salvador, BA, Northeastern Brazil. Questionnaires were used to obtain sociodemographic, occupational, and health-related data. Workers who reported that they worked in places where they needed to shout in order to be heard were considered to be exposed to noise. Exposed workers were asked whether they used hearing protection devices, and if so, how frequently. Analyses were conducted according to gender, with estimates made about prevalence of the use of hearing protection devices, prevalence ratios, and their respective 95% confidence intervals. RESULTS Twelve percent (12.3%) of study subjects reported that they were exposed to noise while working. Prevalence of the use of hearing protection devices was 59.3% for men and 21.4% for women. Men from higher socioeconomic levels (PR = 1.47; 95%CI 1.14;1.90) and who had previous audiometric tests (PR = 1.47; 95%CI 1.15;1.88) were more likely to use hearing protection devices. For women, greater perceived safety was associated with the use of protection devices (PR = 2.92; 95%CI 1.34;6.34). This perception was specifically related to the presence of supervisors committed to safety (PR = 2.09; 95%CI 1.04;4.21), the existence of clear rules to prevent workplace injuries (PR = 2.81; 95%CI 1.41;5.59), and whether they were informed about workplace safety (PR = 2.42; 95%CI 1.23;4.76). CONCLUSIONS There is a gender bias regarding the use of hearing protection devices that is less favorable to women. The use of such devices among women is positively influenced by their perception of a safe workplace, suggesting that gender should be considered as a factor in hearing conservation programs.

OBJETIVO Analisar se dados sociodemográficos, ocupacionais e de saúde estão associados ao uso de equipamento de proteção auditiva no trabalho, segundo gênero. MÉTODOS Estudo transversal com amostra aleatória de 2.429 trabalhadores de 18 a 65 anos de subáreas de base domiciliar em Salvador, BA, no ano de 2006. Foram aplicados questionários para obtenção de dados sociodemográficos, ocupacionais e de saúde. Foram considerados expostos ao ruído aqueles que relataram trabalhar em local onde era necessário gritar para ser ouvido. Os trabalhadores expostos foram questionados sobre uso e regularidade do uso de equipamento de proteção auditiva. A análise foi conduzida por gênero, estimando-se a prevalência do uso do equipamento de proteção auditiva, razões de prevalência e os respectivos intervalos de 95% de confiança. RESULTADOS Entre os participantes do estudo, 12,3% referiram trabalhar expostos ao ruído. A prevalência do uso do equipamento de proteção auditiva foi 59,3% e 21,4%, para homens e mulheres, respectivamente. Entre os homens, maior nível socioeconômico (RP = 1,47; IC95% 1,14;1,90) e ter realizado audiometria (RP = 1,47; IC95% 1,15;1,88) foram fatores associados ao uso do equipamento. Entre as mulheres, a percepção de maior segurança associou-se ao uso do equipamento (RP = 2,92; IC95% 1,34;6,34). Essa percepção deveu-se, especialmente, à presença de supervisores comprometidos com a segurança (RP = 2,09; IC95% 1,04;4,21), à existência de regras claras para evitar acidentes de trabalho (RP = 2,81; IC95% 1,41;5,59) e ao recebimento de informações sobre segurança no trabalho (RP = 2,42; IC95% 1,23;4,76). CONCLUSÕES Há um viés de gênero em relação ao uso do equipamento de proteção auditiva menos favorável às mulheres em comparação com os homens. O uso do equipamento entre mulheres é influenciado positivamente pela percepção de um ambiente de trabalho seguro, sugerindo que o gênero precisa ser considerado nos programas de conservação auditiva.