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.

Protection of sulforaphane against hydrogen peroxide-induced bovine trabecular meshwork cell apoptosis / 中华实验眼科杂志

Background Evidences indicated that oxidative stress damage is an essential pathological process in primary open angle glaucoma.Sulforaphane (SFN) can play an antioxidative stress role to many tissues and cells by activating Nrf2/ARE single pathway.However,whether SFN has a protective role to oxidative stress induced damage of trabecular meshwork cells is still unclear.Objective This study was to investigate the antioxidant effect of SFN against H2O2-induced oxidative damage in bovine trabecular meshwork cells.Methods Trabecular cells were isolated from fresh black bovine eyeballs and primarily cultured and passaged.The third generation of cells were incubated to 96-well dish at a density of 1 ×103/well for 24 hours and divided into 4 groups.The cells were incubated using 100 μl serum-free medium in the blank control group.Oxidative damage models were established by adding 100 μmol/L H2O2(100 μl) in medium in the H2O2 group.The cells were cultured with the medium containing 10 μmol/L SFN (100 μl) in the SFN group,and 100 μl H2O2 at the final concentration of 100 μmol/L was added in the SFN-treated cell medium in the SFN +H2O2 group.The cell vitality in various groups was assayed by using cell counting kit-8 (CCK-8).The apoptosis rate of the cells was detected by Annexin V-FITC/PI double-staining with flow cytometry.Results Cultured cells showed a spindle shape with uniform size,abundant cytoplasm,numberous pigmented particles and big nucleolus.The relative cell vitality reduced to (67.00± 1.27)％ and (80.00±6.25)％ in the H2O2 group and SFN+H2O2 group in comparison with 100％ in the blank control group,and the cell vitality in the SFN+ H2O2 group was lower than that in the SFN group but higher than that in the H2 O2 group (both at P＜0.01).The mean apoptosis rate was (11.33 ±0.77) ％,(32.31 ± 1.03) ％,(10.44 ±0.68) ％ and (17.68 ±0.21) ％ in the blank control group,H2 O2 group,SFN group and SFN+H2O2 group,respectively,showing a significant difference among the groups (F=539.96,P＜0.01),and the apoptosis rate in the SFN+H2O2 group was significantly lower than that in the H2O2 group but higher than that in the blank control group and SFN group (all at P＜0.01).Conclusions SFN can improve the antioxidative stress ability of trabecular meshwork cells and alleviate the damage induced by oxidative stress.