乌灵胶囊干预耳鸣模型大鼠听觉功能的变化及机制

Changes of auditory function and mechanisms in tinnitus rats treated by Wuling Capsule

背景:临床目前尚无标准的治愈耳鸣方案。乌灵胶囊是从乌灵参中提取的经过现代生物学技术提取纯中药制剂,成分为乌灵菌粉,具有养心安神、补肾健脑功效。目的:观察乌灵胶囊对耳鸣大鼠听觉功能的改善作用及其对听觉通路中神经元可塑性相关基因的影响。方法:选取SPF级雄性Wistar大鼠75只,除正常组外,均采用饮水抑制法制备耳鸣大鼠模型,成功造模后模型组15只与正常组15只灌胃生理盐水,卡马西平组15只灌胃卡马西平药液,乌灵胶囊低、高剂量组各15只分别灌胃40,80mg乌灵胶囊药液,持续给药4周。观察各组大鼠饮水抑制率Rb变化、旷场行为学变化、听性脑干反应阈值、初级听皮质病理、听皮质超微结构变化、听觉中枢的神经递质γ-氨基丁酸及5-羟色胺的水平变化和听皮质、耳蜗核、下丘及上橄榄核内可塑性相关基因表达。结果与结论:①乌灵胶囊低、高剂量组及卡马西平组大鼠在条件反射消减期(7d内)的反射抑制率Rb的均值显著低于模型组(P<0.05);②造模后第15天,模型组及各给药组的运动总行程、平均速度和直立次数均显著少于正常组,粪便粒数显著多于正常组(P<0.05),末次给药后,各给药组运动总行程、平均速度和直立次数均显著多于模型组,粪便粒数显著少于模型组(P<0.05);③与模型组相比,乌灵胶囊低、高剂量组大鼠下丘脑γ-氨基丁酸及5-羟色胺水平显著增加(P<0.05),乌灵胶囊低、高剂量组大鼠听皮质、下丘及耳蜗核内细胞骨架蛋白表达降低(P<0.05);④结果证实,乌灵胶囊显著减轻耳鸣大鼠听觉通路中神经元细胞的损伤程度,改善听觉中枢超微结构,降低听性脑干反应阈值,从而提高耳鸣大鼠的听觉功能,改善了焦虑、抑郁的情绪,其机制可能与提高下丘脑γ-氨基丁酸及5-羟色胺水平,改善耳鸣大鼠听觉通路中神经元可塑性相关基因的表达有关。实验已经柳州市人民医院医学伦理委员会批准(批准号:TRH58689)。

BACKGROUND: There is no standard cure for tinnitus. Wuling Capsule is a pure Chinese medicine preparation extracted from Wuling Ginseng by modern biological technology. Its composition is Wuling powder, which has the functions of nourishing the heart and calming the nerves, nourishing the kidney and strengthening the brain. OBJECTIVE: To explore the effect of Wuling Capsule on the auditory function of tinnitus rats and its neuronal plasticity related genes in auditory central ultrastructure and auditory pathway. METHODS: Seventy-five SPF-level Wistar rats were selected. In addition to the normal group, the other groups of rats were prepared with tinnitus model. After successful modeling, the model group(n=15) and the normal group(n=15) were given normal saline, and the carbamazepine group(n=15) was given carbamazepine solution. The low-and high-dose Wuling Capsule groups were intragastrically administered with 40 and 80 g of Wuling Capsule for 4 weeks. The changes of drinking water inhibition rate Rb, open field behavioral changes, auditory brainstem response threshold, primary auditory cortical pathology, auditory cortex ultrastructural changes, auditory central neurotransmitter γ-aminobutyric acid, 5-hydroxytryptamine were observed in the cortex, cochlear nucleus, inferior colliculus and upper olive. RESULTS AND CONCLUSION:(1) The mean Rb in the high-and low-dose Wuling Capsule groups and the carbamazepine group in the conditioned reflex period(within 7 days) was significantly lower than that in the model group(P < 0.05).(2) On day 15 after modeling, the total stroke, average speed and erecting times in the model group and each drug-administered group were significantly lower than those in the normal control group, and the number of fecal pellets was significantly higher than that in the normal control group(P < 0.05). After the treatment, the total stroke, average speed and erecting times in the drug-administered groups were significantly higher than those in the model group, and the number of fecal pellets was significantly lower than that in the model group(P < 0.05).(3) Compared with the model group, the levels of γ-aminobutyric acid and 5-hydroxytryptamine in the hypothalamus were significantly increased(P < 0.05), and expression of cytoskeletal proteins in the auditory cortex, inferior colliculus and cochlear nucleus decreased in the low-and high-dose Wuling Capsule groups(P < 0.05).(4) These results indicate that Wuling Capsule significantly reduces the degree of neuronal damage in the auditory pathway of tinnitus rats, improves the ultrastructure of the auditory center, and lowers the auditory brainstem response threshold, thereby improving the auditory function of tinnitus rats and improving the anxiety and depression. The mechanism may be increasing the levels of γ-aminobutyric acid and 5-hydroxytryptamine in the hypothalamus and improving the expression of neuronal plasticity-related genes in the auditory pathway of tinnitus rats. The study was approved by the Ethical Committee of Liuzhou General Hospital, approval No. TRH58689.