ascorbic-acid and Tinnitus

To perform a trial to assess the efficacy of radical scavengers, i.e. rebamipide, vitamin C and glutathione, for the treatment of Ménière's disease (MD).. Rebamipide (300 mg/day), vitamin C (600 mg/day) and/or glutathione (300 mg/day) were given orally for at least 8 weeks to 25 patients with poorly controlled MD.. Of 22 patients, 21 showed marked improvement of vertigo; 12/27 ears showed improvement of hearing disorders; 17/27 ears showed improvement of tinnitus; and 18/25 patients showed improvement of disability.. This study suggests that treatment using radical scavengers has the potential to become an effective new therapy for MD.

Topics: Adult; Aged; Alanine; Antioxidants; Ascorbic Acid; Female; Free Radical Scavengers; Glutathione; Hearing Loss; Humans; Male; Meniere Disease; Middle Aged; Pilot Projects; Quinolones; Tinnitus; Treatment Failure; Vertigo

Topics: Adult; Ascorbic Acid; Clinical Trials as Topic; Dihydrostreptomycin Sulfate; Drug Eruptions; Eosinophilia; Female; Headache; Humans; Male; Middle Aged; Streptomycin; Sulfates; Tinnitus; Tuberculosis, Pulmonary; Vertigo

Tinnitus is a widespread and serious clinical and social problem. Although oxidative injury has been suggested to be one of pathological mechanisms in auditory cortex, whether this mechanism could be applied to inferior colliculus remains unclear. In this study, we used an online electrochemical system (OECS) integrating in vivo microdialysis with selective electrochemical detector to continuously monitor the dynamics of ascorbate efflux, an index of oxidative injury, in inferior colliculus of living rats during sodium salicylate-induced tinnitus. We found that OECS with a carbon nanotubes (CNTs)-modified electrode as the detector selectively responses to ascorbate, which is free from the interference from sodium salicylate and MK-801 that were used to induce tinnitus animal model and investigate the N-methyl-d-aspartate (NMDA) receptor mediated excitotoxicity, respectively. With the OECS, we found that the extracellular ascorbate level in inferior colliculus significantly increases after salicylate administration and such increase was suppressed by immediate injection of NMDA receptor antagonist MK-801. In addition, we found that salicylate administration significantly increases the spontaneous and sound stimuli evoked neural activity in inferior colliculus and that the increases were inhibited by the injection of MK-801. These results suggest that oxidative injury may occur in inferior colliculus following salicylate-induced tinnitus, which is closely relevant to the NMDA-mediated neuronal excitotoxicity. This information is useful for understanding the neurochemical processes in inferior colliculus involved in tinnitus and its related brain diseases.

Topics: Ascorbic Acid; Disease Models, Animal; Dizocilpine Maleate; Electrochemical Techniques; Inferior Colliculi; Oxidative Stress; Salicylates; Sodium Salicylate; Tinnitus

Tinnitus may cause anxiety, depression, insomnia, which impair the quality of life of millions worldwide. However, the mechanism of tinnitus remains to be understood, it has been previously hypothesized that the activation of N-methyl-D-aspartate (NMDA) receptor is involved in the tinnitus processes and blockade of the NMDA receptor is regarded as a therapeutic strategy for tinnitus treatment even if the rescue treatment is still proved invalid in some cases. To demonstrate the therapeutic effect of the NMDA receptor blocker on tinnitus, we examined here the spontaneous firing rate (SFR) and the neurochemical dynamics in the auditory cortex (AC) of rats after sodium salicylate (SS) injection, which is a widely used model for tinnitus research. We also recorded their responses to MK-801 treatment. Electrophysiological studies showed that MK-801 significantly suppresses SFR in AC of rats with SS-induced tinnitus. In addition, by using a technique that combining in vivo microdialysis with an online electrochemical system (OECS) and a high-performance liquid chromatography (HPLC), we found that the levels of both glutamate and ascorbate in AC dramatically increased after SS injection and that MK-801 administration attenuated those response. Further studies found that MK-801 given at a time point of 30 min pre- or post-injection of SS were more effective than that given at a time point of 60 min post-SS injection, indicating that the time point of MK-801 intervention has a critical impact on the therapeutic effect. These findings suggest that MK-801 plays a neuroprotective role against hyperactivity during tinnitus induced by SS and that the therapeutic effect depends on the time point of MK-801 intervention, which would advance the studies on understanding of the therapeutic potential of NMDA receptor antagonist in tinnitus therapy.

Topics: Animals; Ascorbic Acid; Auditory Cortex; Disease Models, Animal; Dizocilpine Maleate; Drug Administration Schedule; Evoked Potentials, Auditory; Glutamic Acid; Humans; Male; Neuroprotective Agents; Rats; Rats, Sprague-Dawley; Receptors, N-Methyl-D-Aspartate; Sodium Salicylate; Tinnitus

To determine the correlation between plasma levels of melatonin, vitamin C and vitamin B12 and the presence of tinnitus among elderly subjects with unexplained subjective tinnitus.. Prospective involving apparently healthy elderly with subjective tinnitus and those without. Plasma levels of melatonin, vitamin C and vitamin B12 were determined using high performance liquid chromatography and correlation determined by comparing subjects with and without tinnitus.. There were 139 elderly subjects (78 females and 61males), the mean(SD) range of the age was 66.9years (0.77) 60-98 years. Of these 58.3% had tinnitus. The mean (SD) range of the plasma levels of melatoninn was 11.2 pg/mL(4.2) 5.1 pg/mL - 30.2 pg/mL while that of Vitamin C was 0.7 µmol/L (0.1) 0.3 µmol/L - 1.2 µmol/L, and vitamin B12 was 43.0pmol/L (3.1) 25.4 pmol/L - 71.6pmol/L. Comparing the plasma levels of the markers between elderly with and those without tinnitus, the plasma levels of melatonin (p=0.01) and vitamin B12 (p=0.03) were significantly lower among the elderly with tinnitus compared to those without, while the difference in the plasma level of vitamin C (p=0.6) was not.. Low plasma melatonin and vitamin B12 have significant correlation with the development of subjective idiopathic tinnitus among the elderly. This finding suggests the need for the trial of correction of these markers in the reversal or control of tinnitus.

Topics: Aged; Aged, 80 and over; Ascorbic Acid; Chromatography, High Pressure Liquid; Female; Humans; Male; Melatonin; Middle Aged; Prospective Studies; Tinnitus; Vitamin B 12

As one of the most important neurochemicals in biological systems, ascorbate plays vital roles in many physiological and pathological processes. In order to understand the roles of ascorbate in the pathological process of tinnitus, this study demonstrates an in vivo method for real time monitoring of the changes of ascorbate level in the cochlear perilymph of guinea pigs during the acute period of tinnitus induced by local microinfusion of salicylate with carbon fiber microelectrodes (CFMEs) modified with multiwalled carbon nanotubes (MWNTs). To accomplish in vivo electrochemical monitoring of ascorbate in the microenvironment of the cochlear perilymph, the MWNT-modified CFME is used as working electrode, a microsized Ag/AgCl is used as reference electrode, and Pt wire is used as counter electrode. Three electrodes are combined together around a capillary to form integrated capillary-electrodes. The integrated capillary-electrode is carefully implanted into the cochlear perilymph of guinea pigs and used both for externally microinfusing of salicylate into the cochlear perilymph and for real time monitoring of the change of ascorbate levels. The in vivo voltammetric method based on the integrated capillary-electrodes possesses a high selectivity and a good linearity for ascorbate determination in the cochlear perilymph of guinea pigs. With such a method, the basal level of cochlear perilymph ascorbate is determined to be 45.0 ± 5.1 μM (n = 6). The microinfusion of 10 mM salicylate (1 μL/min, 5 min) into the cochlear decreases the ascorbate level to 28 ± 10% of the basal level (n = 6) with a statistical significance (P < 0.05), implying that the decrease in ascorbate level in the cochlear may be associated with salicylate-induced tinnitus. This study essentially offers a new method for in vivo monitoring of the cochlear perilymph ascorbate following the salicylate-induced tinnitus and can thus be useful for investigation on chemical essences involved in tinnitus.

Topics: Animals; Ascorbic Acid; Cochlea; Electrochemistry; Electrodes; Guinea Pigs; Male; Perilymph; Salicylic Acid; Tinnitus

Patients with stages I and II of vascular encephalopathy developing on the background of atherosclerosis were treated with ascovertin during 21 days. Ascovertin is a complex of flavonoid dihydroquercetin and ascorbic acid. The study group included 21 patients aged 45-65 years and a comparison group consisted of 10 age-matched patients un treated with ascovertin. The ascovertin treatment relieved headache, reduced vertigo and fatigability, improved cognitive functions. The reliable diminishing of whole blood viscosity due to improvement of cellular rheology indices (decrease of aggregation and increase of erythrocyte deformability as well as decrease of indices of lipid peroxidation in erythrocyte membrane and blood plasma) was observed in the stydy group but not in the comparison one.

Topics: Aged; Antioxidants; Ascorbic Acid; Blood Viscosity; Drug Combinations; Erythrocyte Aggregation; Erythrocyte Deformability; Flavonols; Headache; Hemorheology; Humans; Intracranial Arteriosclerosis; Lipid Peroxidation; Middle Aged; Neuropsychological Tests; Quercetin; Sleep Wake Disorders; Tinnitus; Vertigo