中药复方健耳剂对C57BL/6J小鼠老年性聋的防护效应

Protecting Effects of Jian'erji on Age-related Hearing Loss of C57BL/6J Mice

目的观察C57BL/6J小鼠老年性听力下降现象并研究中药复方健耳剂对老年性聋小鼠的保护作用及其可能机制。方法将36只C57BL/6J小鼠分为正常对照组（n=6）、老年性聋对照组（n=12）及高剂量中药健耳剂组（简称中药高剂量组,n=12）及低剂量中药健耳剂组（简称中药低剂量组,n=6）。正常对照组小鼠自断奶后每日饮用自来水直至出生后2个月;老年性聋对照组小鼠自断奶后每日饮用自来水直至出生后7个月;中药高、低剂量组小鼠自断奶后分别每日饮用3.65、0.91 g/（kg·d）的中药复方健耳剂直至出生后7个月。每组6只小鼠在实验终止日应用听性脑干诱发电位仪检测小鼠的听性脑干反应（auditory brainstem response,ABR）阈。中药高剂量组与同期老年性聋对照组6只小鼠在终止实验即刻取出耳蜗、听皮层脑组织及肝脏,采用丙二醛考马斯亮蓝试剂盒,利用紫外分光光度计,检测所取组织中丙二醛含量。结果2月龄正常对照组小鼠在4-48 KHz频率范围的不同短纯音诱发的ABR阈值保持正常。与2月龄正常对照组比较,7月龄老年性聋对照组小鼠ABR阈值明显升高（P〈0.05）,与高剂量中药组在8-48 KHz频率范围ABR阈值比较,差异亦有统计学意义（P〈0.05）。与7月龄老年性聋对照组比较,高剂量中药组小鼠耳蜗、听皮层、肝脏组织中丙二醛含量明显降低（P〈0.01）。结论 C57BL/6J小鼠在出生后7个月表现出明显的高频性老年性聋症状。每日饮用高剂量中药健耳剂可显著延缓老年性聋的发生和发展。中药健耳剂保护听觉延缓老年性聋发生的作用,可能与其所含中药的抗氧化效应有关。

Objective To observe decreased hearing in aged C57 BL /6J mice,and to study protective effects of Jian＇erji（ JEJ） for age-related hearing loss（ AHL） and its possible mechanism. Methods Totally 36C57 BL / 6J mice were randomly divided into four groups,i. e.,the normal control group（n = 6）,the AHL control group（n = 12）,the high dose JEJ group（n = 12）,the low dose JEJ group（n = 6）. Mice in the normal control group drank tap water from ablactation till 2 months old. Mice in the AHL control group drank tap water from ablactation till 7 months old. Mice in high and low dose JEJ groups drank JEJ at the daily dose of 3. 65 g / kg and0. 91 g / kg respectively from ablactation till 7 months old. Six mice were selected from each group for auditory brainstem response（ ABR） using brainstem evoked potentiometer on the day of ending the test. The cochlear tissue,auditory cortex,and liver were immediately collected from 6 mice of the high dose JEJ group and 6 of the AHL control group at the same ages. Contents of malondialdehyde（ MDA）,end product of lipid peroxidation were detected by UV spectrophotometer using MDA coomassie blue kit. Results ABR thresholds evoked by short-pure tone from4 to 48 KHz were in the normal range of 2 months old mice in the normal control group. Compared with 2 months old mice in the normal control group,ABR thresholds were significantly elevated in 7 months old mice of the AHL control group（P〈0. 05）. Significant differences also existed in ABR thresholds from 8 to 48 KHz in the high dose JEJ group（P〈0. 05）. Compared with 7 months old mice of the AHL control group,MDA contents in cochlear tissue,auditory cortex,and liver were obviously reduced in the high dose JEJ group（P〈0. 01）. Conclusions C57 BL / 6J mice showed significant symptoms of AHL in high frequency range at 7 months old. Daily drinking of high dose JEJ could significantly delay the occurrence and progress of AHL. Its protection might be related to antioxidant effects JEJ contained.