Curcumin-Encapsulated Chitosan-Coated Nanoformulation as an Improved Otoprotective Strategy for Ototoxic Hearing Loss.

Overexpression of apoptotic factors in the inner ear is generally proven to induce ototoxicity. This has aroused research interest in various antiapoptotic drugs, the most representative of which is curcumin (CUR). In this study, two nanoformulations of CUR were developed with sustained-release behavior to improve their protective effects against ototoxic hearing loss (HL), which were the nanoparticles of CUR-loaded poly(lactic acid-glycolic acid) (CUR-PLGA NPs) and CUR-loaded chitosan-coated PLGA NPs (CUR-CS/PLGA NPs). The obtained results revealed that both CUR-NPs provided otoprotection in vitro and in vivo, and their effective doses in guinea pigs were much less than that of dexamethasone, which was clinically used to treat HL. Moreover, relative to CUR and CUR-PLGA NPs, CUR-CS/PLGA NPs exhibited the highest accumulation in HEI-OC1 cells and guinea pigs' cochlea. In pharmacodynamic experiments, the optimal administration timing was investigated, and CUR-CS/PLGA NPs showed sustained efficacy and the best hearing improvement at all tested sound frequencies. Lastly, the protective effect of CUR nanoformulations was further validated via inhibition of Caspase-3 and Bax activation, thereby reducing the concentration of reactive oxygen species and protecting mitochondrial integrity in hair cells. Collectively, CUR-CS/PLGA NPs demonstrated potent and lasting effects against ototoxic HL, making our novel formulation a promising candidate for the alleviation of sensorineural HL.

CircHIPK3 promotes proliferation and invasion in nasopharyngeal carcinoma by abrogating miR-4288-induced ELF3 inhibition.

Circular RNAs (circRNAs) are reported to regulate the development and progression of multiple cancers. However, the functions of circRNAs in nasopharyngeal carcinoma (NPC) are unclear. In this study, we identified that circular homeodomain interacting protein kinase 3 (circHIPK3) was highly expressed in NPC tissues and cell lines. Moreover, we found that circHIPK3 expression levels could act as a prognostic marker in NPC patients. We showed that circHIPK3 silence repressed NPC cell proliferation, migration, and invasion in vitro. In addition, circHIPK3 depletion dramatically repressed tumor growth and metastasis in vivo. Mechanistically, we revealed circHIPK3 as a competing endogenous RNA of microRNA (miR)-4288 that targets E74-like ETS transcription factor 3 (ELF3) in NPC cells. We found that miR-4288 inhibition reversed the effects of circHIPK3 silence on NPC cells. Furthermore, rescue assays also indicated that circHIPK3 promoted the malignant behaviors of NPC cells via enhancing ELF3 expression by suppressing the miR-4288 levels. In conclusion, our findings demonstrated that circHIPK3 facilitated NPC progression through protecting ELF3 from miR-4288-mediated silencing, which suggested that the circHIPK3-miR-4288-ELF3 regulatory loop might be a potential target for NPC prevention.

Quantitative proteome and lysine succinylome characterization of zinc chloride smoke-induced lung injury in mice.

The inhalation of zinc chloride (ZnCl2) smoke is one of common resources of lung injury, potentially resulting in severe pulmonary complications and even mortality. The influence of ZnCl2 smoke on lysine succinylation (Ksucc) in the lungs remains uncertain. In this study, we used a ZnCl2 smoke inhalation mouse model to perform global proteomic and lysine succinylome analyses. A total of 6781 Ksucc sites were identified in the lungs, with injured lungs demonstrating a reduction to approximately 2000 Ksucc sites, and 91 proteins exhibiting at least five differences in the number of Ksucc sites. Quantitative analysis revealed variations in expression of 384 proteins and 749 Ksucc sites. The analysis of protein-protein interactions was conducted for proteins displaying differential expression and differentially expressed lysine succinylation. Notably, proteins with altered Ksucc exhibited increased connectivity compared with that in differentially expressed proteins. Beyond metabolic pathways, these highly connected proteins were also involved in lung injury-associated pathological reactions, including processes such as focal adhesion, adherens junction, and complement and coagulation cascades. Collectively, our findings contribute to the understanding of the molecular mechanisms underlaying ZnCl2 smoke-induced lung injury with a specific emphasis on lysine succinylation. These findings could pave the way for targeted interventions and therapeutic strategies to mitigate severe pulmonary complications and mortality associated with such injuries in humans.

Ferroptosis and PPAR-gamma in the limelight of brain tumors and edema.

Human malignant brain tumors such as gliomas are devastating due to the induction of cerebral edema and neurodegeneration. A major contributor to glioma-induced neurodegeneration has been identified as glutamate. Glutamate promotes cell growth and proliferation in variety of tumor types. Intriguently, glutamate is also an excitatory neurotransmitter and evokes neuronal cell death at high concentrations. Even though glutamate signaling at the receptor and its downstream effectors has been extensively investigated at the molecular level, there has been little insight into how glutamate enters the tumor microenvironment and impacts on metabolic equilibration until recently. Surprisingly, the 12 transmembrane spanning tranporter xCT (SLC7A11) appeared to be a major player in this process, mediating glutamate secretion and ferroptosis. Also, PPARγ is associated with ferroptosis in neurodegeneration, thereby destroying neurons and causing brain swelling. Although these data are intriguing, tumor-associated edema has so far been quoted as of vasogenic origin. Hence, glutamate and PPARγ biology in the process of glioma-induced brain swelling is conceptually challenging. By inhibiting xCT transporter or AMPA receptors in vivo, brain swelling and peritumoral alterations can be mitigated. This review sheds light on the role of glutamate in brain tumors presenting the conceptual challenge that xCT disruption causes ferroptosis activation in malignant brain tumors. Thus, interfering with glutamate takes center stage in forming the basis of a metabolic equilibration approach.

Murine cytomegalovirus employs the mixed lineage kinases family to regulate the spiral ganglion neuron cell death and hearing loss.

Cytomegalovirus (CMV)-induced sensorineural hearing loss (SNHL) is a worldwide epidemic. Recent studies have shown that the degree of spiral ganglion neuron (SGN) loss is correlated with hearing loss after CMV infection. We aimed to better understand the pathological mechanisms of CMV-related SGN death and to search for intervention measures. We found that both apoptosis and pyroptosis are involved in CMV-induced SGN death, which may be caused by the simultaneous activation of the p53/JNK and NLRP3/caspase-1 signaling pathways, respectively. Moreover, considering that mixed lineage kinase family (MLK1/2/3) are host restriction factors against viral infection and upstream regulators of the p53/JNK and inflammatory (including NLRP3-caspase1) signaling pathways, we further demonstrated that the MLKs inhibitor URMC-099 exhibited a protective effect against CMV-induced SGN death and hearing loss. These results indicate that MLKs signaling may be a key regulator and promising novel target for preventing apoptosis and even pyroptosis during the CMV infection of SGN cells and for treating hearing loss.

In vivo visualization and analysis of ciliary motion in allergic rhinitis models induced by ovalbumin.

Due to the lack of an assessment approach, the image of in vivo nasal ciliary motion of allergic rhinitis (AR) has never been captured and analyzed to date. Here, we have used an optimized approach to analyze the nasal ciliary function in vivo in AR rats. The digital microscopy system, a method for direct observation of ciliary motion in a living AR rat model, was applied to visualize and measure ciliary motion in vivo, including ciliary beat frequency (CBF) and ciliary beat distance (CBD). The AR rat model was established by ovalbumin sensitization. Comparisons of nasal ciliary motion in vivo between the experimental group (ovalbumin sensitization, allergen, or histamine) and the control group were analyzed. In the living rat model of allergic rhinitis, CBF and CBD decreased to 57.8 and 73.1% of the control group, respectively, but were restored after administration of chlorpheniramine maleate. Ovalbumin (OVA) significantly inhibited the ciliary motion of normal mucosa in vivo. However, responding to the OVA challenge, the ciliary motion of OVA-sensitized mucosa would not decrease further and stay at a stable level. Histamine stimulated in vivo ciliary motion quickly within 30 min, but afterward, the ciliary motion gradually decreased below the baseline. These results have clarified that in vivo ciliary motion was impaired by nasal mucosal sensitization, and this impairment was most likely related to allergen challenge and histamine. In addition, the short-term stimulation and long-term inhibition effects of histamine on in vivo ciliary motion were first reported in this study.

Sonodynamic therapy exciting the herbal nanocomposite with spider-web-like effect to combat otitis media.

Otitis media, mainly caused by bacteria, is prevalent in young children and can cause hearing loss and growth retardation. Antibiotics are the most widely utilized treatment for otitis media, however, they can cause drug resistance and harmful side effects. In this study, we reported an antibacterial nanocomposite in combination with sonodynamic therapy that consists of herbal antibacterial agents such as Curcumin (CUR) and Tanshinone IIA (TSIIA), as well as Chitosan (CS), for the treatment of acute otitis media. CUR/TSIIA/CS nanocomposite (NC) with ultrasonic irradiation demonstrated that it could eliminate Staphylococcus aureus. In vivo experiments revealed that NC-mediated sonodynamic therapy had excellent antibacterial and anti-inflammatory activity, displaying a consistent performance comparable to ofloxacin. The therapeutic efficiency was attributed to capturing bacteria through spider-web-like effect and destroying bacteria through the reactive oxygen species generated under ultrasonic irradiation. Significantly, NC did not induce bacterial resistance and showed good biocompatibility. This study provides a novel strategy to develop an ultrasound-assisted nanocomposite with an enhanced antibacterial effect. Further, it unlocks new doors for the substitute of antibiotics to combat otitis media by establishing efficient therapeutic systems.

Co-activation of Caspase-1 and Caspase-8 in CMV-induced SGN death by inflammasome-associated pyroptosis and apoptosis.

Cytomegalovirus (CMV) infection causes newborn deafness, and the death of the spiral ganglion neurons (SGNs) is crucial in determining the degree of CMV-related hearing loss. Therefore, understanding the psychopathology of CMV-related SGN loss is important for identifying targets and exploring treatment strategies. In this study, we found that pyroptosis and apoptosis, two inflammasome-related programmed cell death pathways, are involved in CMV-induced SGN death and are mainly regulated by activated caspase-1 and caspase-8. Moreover, suppressing inflammasome assembly by blocking apoptosis-associated speck-like protein containing a CARD (ASC) interaction inhibited the activation of both caspase-1 and caspase-8, rescued SGN death, and improved hearing loss in CMV-infected newborn mice. Therefore, we propose that ASC inflammasome might be a promising target for treating CMV-related SGN death and newborn hearing loss by inhibiting caspase-1 and caspase-8 activated pyroptosis and apoptosis.

Outcomes of chronic angle-closure glaucoma treated by phacoemulsification and endocyclophotocoagulation with or without endoscopically goniosynechialysis.

AIM: To investigate the surgical outcomes of patients with chronic angle-closure glaucoma (CACG) treated with phacoemulsification (phaco)/endocyclophotocoagulation (ECP) with and without endoscopic goniosynechialysis (E-GSL). METHODS: A retrospective, nonrandomized, comparative case series was conducted. Patients with CACG who underwent phaco in combination with either ECP alone (ECP group) or GSL with ECP (E-GSL group) from 2018 to 2019 were followed for 12mo and reviewed. Clinical features and outcomes were identified and analyzed. The ECP and E-GSL groups were matched in age and baseline intraocular pressure (IOP). Changes in IOP, mean of visual acuity (VA), peripheral anterior synechiae (PAS) formation, and the number of glaucoma medications was examined. RESULTS: The ECP group included 32 eyes of 27 patients, and the E-GSL group included 32 eyes of 26 patients. The preoperative baseline IOP was 22.18±6.48 mm Hg in the ECP group and 22.95±6.71 mm Hg in the E-GSL group (P=0.644). The mean IOP reduction was 26.2% in the ECP group and 41.6% in the E-GSL group at 12mo. The mean postoperative VA (logMAR units) at 12mo was 0.47 in the ECP group and 0.36 in the E-GSL group. The reduction in PAS formation and the number of glaucoma medications was also higher in the ECP group than E-GSL group at 12mo. CONCLUSION: The phaco/ECP and phaco/E-GSL groups both achieve a significant reduction in IOP without complications associated with traditional glaucoma filtration surgeries.

Novel Application of Photo-Crosslinked Urocanic-Acid-Modified Chitosan in Corneal Wounds.

In the last few years, the use of tissue adhesives in corneal perforation has gained immense popularity in clinical practices. The present study aimed to devise a new application of urocanic-acid-modified chitosan (CS) with methylene blue (MB) as a photosensitizer for the development of a photo-crosslinked tissue adhesive. In particular, the curing time was controlled with the aid of a 650 nm red diode. Under the same irradiation condition, the mechanical properties were tuned using the photosensitizer at different concentrations. In vitro tests revealed that the gel was ductile and biocompatible. The application of the gel to a perforated cornea model stopped the leakage of aqueous humor, immediately after the gel was photo-crosslinked. The blue appearance of the gel provided high precision when applied to corneal wounds. Importantly, the crosslinked gel became transparent within 24 h, owing to the dissipation of MB from tears, and the gel spontaneously sloughed off without artificial removal. Altogether, the study reported the development of a novel photo-crosslinkable urocanic-acid-modified CS gel that exhibited significant potential to be utilized in the healing of corneal perforation.

In vivo and in vitro observation of nasal ciliary motion in a guinea pig model.

IMPACT STATEMENT: Cilia play an important role in the airway defense mechanism. So far, studies on ciliary function have mainly been based on in vitro methods. Images of in vivo ciliary motion are very difficult to capture. In this study, we describe a novel approach to observe and analyze nasal ciliary motion in living animals with comparison to in vitro observation. Such images of ciliary motion from living animals have not been reported to date. The result of the study indicates that in vivo ciliary physiological function differs from ex vivo and in vitro conditions in many ways, such as the stability over time and response to temperature variation. This is a good foundation for further in vivo analysis of airway ciliary physiological function in animals as well as humans.

CircRNA hsa_circ_100395 regulates miR-1228/TCF21 pathway to inhibit lung cancer progression.

Circular RNA (circRNA) is shown to participate in various tumors, including lung cancer. Although a few circRNAs involved in lung cancer are reported, whether circRNA negatively regulates lung cancer development remains elusive. In this study, we showed hsa_circ_100395 expression was decreased in lung cancer tissues. Besides, hsa_circ_100395 level was inversely correlated with TNM stage and metastases in lung cancer and low hsa_circ_100395 expression in patients predicted poor prognosis. Overexpression of hsa_circ_100395 dramatically inhibited lung cancer cell proliferation, arrested cell-cycle progression and reduced cell migration and invasion in vitro. Xenograft experiments showed that hsa_circ_100395 overexpression delayed tumor growth in vivo. Mechanistically, we showed hsa_circ_100395 serves as a sponge for miR-1228 targeting TCF21 in lung cancer. Rescue assays indicated that hsa_circ_100395 regulates lung cancer cell proliferation, migration and invasion through modulating miR-1228/TCF21 pathway. Altogether, our study reveals a novel regulatory loop that hsa_circ_100395/miR-1228/TCF21 axis modulates lung cancer development. ABBREVIATIONS: circRNA: circular RNA; miRNA: microRNA; RNA-FISH: RNA fluorescence in situy bridization; qRT-PCR: Reverse transcription and quantitative real-time PCR.

Diagnostic significance of serum periostin in eosinophilic chronic sinusitis with nasal polyps.

OBJECTIVES: Chronic rhinosinusitis with nasal polyps (CRSwNP) is a heterogeneous disease. Eosinophilic CRSwNP (ENP) exhibits a strong tendency for recurrence after surgery. Given that the treatment strategy of ENP differs from that of non-eosinophilic CRSwNP (nENP), clinical diagnostic criteria that distinguish ENP from nENP are needed. METHODS: In total, 94 CRSwNP patients were enrolled in the cohort. Factors associated with ENP were determined with regression analysis, and optimal cutoff points of the predictors were determined by a receiver operating characteristic curve. RESULTS: Serum periostin levels, blood eosinophils and basophils counts significantly differed between ENP and nENP. A combination of the cut-off values for the three predictors, including absolute blood eosinophil and basophil counts, yielded a sensitivity of 79.2% and 70.8%, and a specificity of 84.8% and 73.9%, respectively. Serum periostin levels yielded a sensitivity of 72.9% and a specificity of 60.9% for the diagnosis of ENP. The predicted probability of periostin in combination with blood eosinophils and basophils counts (AUC, 0.872) exhibited moderate accuracy. In addition, patients with ENP displayed an increased prevalence of smoking. CONCLUSIONS: Periostin in combination with blood eosinophils and basophils counts has the potential to better refine current CRSwNP phenotypes.

Maximal number of pre-synaptic ribbons are formed in cochlear region corresponding to middle frequency in mice.

OBJECTIVE: To investigate whether there are more quantitative pre-synaptic ribbons formed in the cochlear region corresponding to middle-frequency in cochlea of mice. METHODS: Counts of pre-synaptic ribbons were performed using immunostaining and laser confocal microscopy. Hearing thresholds and function of ribbon synapses were estimated by auditory brain response (ABR) and compound action potential (CAP). Cochlear mapping has been achieved to match the frequencies and corresponding regions along the cochlear spiral. RESULTS: The number of pre-synaptic ribbons in per inner hair cell (IHC) has been found to increase gradually from the base turn, the maximal quantity appeared at the region of 50-70% from the apex. Next, ABR thresholds showed that there was the lowest ABR threshold in the frequency around 8-16 kHz, corresponding to the region of 50-70% from the apex according to the cochlear mapping. Further, CAP amplitudes were estimated, and the maximal value identified at the same frequency (8-16 kHz). CONCLUSIONS: Maximal number of pre-synaptic ribbons is formed in the cochlear region of middle frequency in mice, coupling with the lowest ABR threshold and highest CAP amplitudes. Our study shows that the middle frequency (8-16 kHz) could be the most sensitive region to sound stimuli in mice.

Ferroptosis and Cell Death Analysis by Flow Cytometry.

Cell death and its recently discovered regulated form ferroptosis are characterized by distinct morphological, electrophysiological, and pharmacological features. In particular ferroptosis can be induced by experimental compounds and clinical drugs (i.e., erastin, sulfasalazine, sorafenib, and artesunate) in various cell types and cancer cells. Pharmacologically, this cell death process can be inhibited by iron chelators and lipid peroxidation inhibitors. Relevance of this specific cell death form has been found in different pathological conditions such as cancer, neurotoxicity, neurodegeneration, and ischemia. Distinguishing cell viability and cell death is essential for experimental and clinical applications and a key component in flow cytometry experiments. Dead cells can compromise the integrity of the data by nonspecific binding of antibodies and dyes. Therefore it is essential that dead cells are robustly and reproducibly identified and characterized by means of cytometry application. Here we describe a procedure to detect and quantify cell death and its specific form ferroptosis based on standard flow cytometry techniques.

Histone deacetylases in hearing loss: Current perspectives for therapy.

Hearing loss is one of the most frequent health issues in industrialized countries. The pathogenesis and molecular mechanisms of hearing loss are still unclear. Histone deacetylases (HDACs) are emerging as key enzymes in many physiological processes, including chromatin remodeling, regulation of transcription, DNA repair, metabolism, genome stability and protein secretion. Recent studies indicated that HDACs are associated with the development and progression of hearing loss. Dysfunction of HDACs could promote the oxidative stress and aging in the inner ear. In light of considering the current stagnation in the development of therapeutic options, the need for new strategies in the treatment of hearing loss has never been so pressing. In this review, we will summarize the reported literatures for HDACs in hearing loss and discuss how HDAC family members show different performances for the possibility of process of diseases development. The possibility of pharmacological intervention on hearing loss opens a novel path in the treatment of hearing loss.

The Role of Periostin in the Occurrence and Progression of Eosinophilic Chronic Sinusitis with Nasal Polyps.

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a highly heterogeneous disease with different host defence responses. However, whether periostin and vascular endothelial growth factor (VEGF) are similarly impaired in patients with eosinophilic CRSwNP (ENP) and those with non-eosinophilic CRSwNP (nENP) remains unclear. We sought to evaluate the expression and possible modulation of periostin and VEGF, regulated on activation normal T expressed and secreted (RANTES) and eotaxin-2 in the polyp tissues from 30 patients with ENP and from 36 patients with nENP and in middle turbinate tissues from 12 control subjects. We found that ENP tissues exhibited a significantly increased expression of periostin and VEGF compared with tissues from patients with nENP and control subjects (P < 0.05, respectively). Accordingly, the expression of VEGF, RANTES, and eotaxin-2 in ENP fibroblasts was significantly up-regulated after stimulation with up-regulated periostin in vitro, but the expression of VEGF and RANTES was significantly inhibited by stimulation with down-regulated periostin. Our findings suggest that periostin might play an important role in the occurrence and progression of ENP and might be a potential therapeutic target.

The oxido-metabolic driver ATF4 enhances temozolamide chemo-resistance in human gliomas.

Malignant gliomas are devastating neoplasia with limited curative treatment options. Temozolomide (TMZ, Temcat®, Temodal® or Temodar®) is a first-line treatment for malignant gliomas but the development of drug resistance remains a major concern. Activating transcription factor 4 (ATF4) is a critical oxido-metabolic regulator in gliomas, and its role in the pathogenesis of TMZ-resistance remains elusive. We investigated the effect of TMZ on human glioma cells under conditions of enhanced ATF4 expression (ATF4OE) and ATF4 knock down (ATF4KD). We monitored cell survival, ATF4 mRNA expression of ATF4 and xCT (SLC7a11) regulation within human gliomas. TMZ treatment induces a transcriptional response with elevated expression of ATF4, xCT and Nrf2, as a sign of ER stress and toxic cell damage response. ATF4 overexpression (ATF4OE) fosters TMZ resistance in human gliomas and inhibits TMZ-induced autophagy. Conversely, ATF4 suppression by small interfering RNAs (ATF4KD) leads to increased TMZ susceptibility and autophagy in comparison to wild type gliomas. ATF4OE gliomas show reduced cell cycle shift and apoptotic cell death, whereas ATF4KD gliomas reveal higher susceptibility towards cell cycle rearrangements. Hence, the migration capacity of ATF4OE glioma cells is almost not affected by TMZ treatment. In contrast, ATF4KD gliomas show a migratory stop following TMZ application. Mechanistically, xCT elevation is a consequence of ATF4 activation and increased levels of xCT amplifies ATF4-induced TMZ resistance. Our data show that ATF4 operates as a chemo-resistance gene in gliomas, and the tumor promoting function of ATF4 is mainly determined by its transcriptional target xCT. Therefore, therapeutic inactivation of ATF4 can be a promising strategy to overcome chemo-resistance and promote drug efficacy in human gliomas.

Chemotherapeutic xCT inhibitors sorafenib and erastin unraveled with the synaptic optogenetic function analysis tool.

In the search for new potential chemotherapeutics, the compounds' toxicity to healthy cells is an important factor. The brain with its functional units, the neurons, is especially endangered during the radio- and chemotherapeutic treatment of brain tumors. The effect of the potential compounds not only on neuronal survival but also neuronal function needs to be taken into account. Therefore, in this study we aimed to comprehend the biological effects of chemotherapeutic xCT inhibition on healthy neuronal cells with our synaptic optogenetic function analysis tool (SOFA). We combined common approaches, such as investigation of morphological markers, neuronal function and cell metabolism. The glutamate-cystine exchanger xCT (SLC7A11, system Xc-) is the main glutamate exporter in malignant brain tumors and as such a relevant drug target for treating deadly glioblastomas (WHO grades III and IV). Recently, two small molecules termed sorafenib (Nexavar) and erastin have been found to efficiently block xCT function. We investigated neuronal morphology, metabolic secretome profiles, synaptic function and cell metabolism of primary hippocampal cultures (containing neurons and glial cells) treated with sorafenib and erastin in clinically relevant concentrations. We found that sorafenib severely damaged neurons already after 24 h of treatment. Noteworthy, also at a lower concentration, where no morphological damage or metabolic disturbance was monitored, sorafenib still interfered with synaptic and metabolic homeostasis. In contrast, erastin-treated neurons displayed mostly inconspicuous morphology and metabolic rates. Key parameters of proper neuronal function, such as synaptic vesicle pool sizes, were however disrupted following erastin application. In conclusion, our data revealed that while sorafenib and erastin effectively inhibited xCT function they also interfered with essential neuronal (synaptic) function. These findings highlight the particular importance of investigating the effects of potential neurooncological and general cancer chemotherapeutics also on healthy neuronal cells and their function as revealed by the SOFA tool.

Molecular mechanisms underlying the protective effects of hydrogen-saturated saline on noise-induced hearing loss.

OBJECTIVES: This study aimed to explore the molecular mechanism of the protective effects of hydrogen-saturated saline on NIHL. METHODS: Guinea pigs were divided into three groups: hydrogen-saturated saline; normal saline; and control. For saline administration, the guinea pigs were given daily abdominal injections 3 d before and 1 h before noise exposure. ABR were tested to examine cochlear physiology changes. The changes of 8-hydroxy-desoxyguanosine (8-HOdG), interleukin-1 (IL-1), interleukin-6 (IL-6), interleukin-10 (IL-10), tumor necrosis factor-α (TNF-α), intercellular cell adhesion molecule-1 (ICAM-1) and high mobility group box-1 protein (HMGB1) in the cochlea were also examined. RESULTS: The results showed that pre-treatment with hydrogen-saturated saline could significantly attenuate noise-induced hearing loss. The concentration of 8-HOdG was also significantly decreased in the hydrogen-saturated saline group compared with the normal saline group. After noise exposure, the concentrations of IL-1, IL-6, TNF-α, and ICAM-1 in the cochlea of guinea pigs in the hydrogen-saturated saline group were dramatically reduced compared to those in the normal saline group. The concentrations of HMGB-1 and IL-10 in the hydrogen-saturated saline group were significantly higher than in those in the normal saline group immediately and at 7 d after noise exposure. CONCLUSIONS: This study revealed for the first time the protective effects of hydrogen-saturated saline on noise-induced hearing loss (NIHL) are related to both the anti-oxidative activity and anti-inflammatory activity.