Oral Administration of Caffeine Exacerbates Cisplatin-Induced Hearing Loss

Association of coffee consumption with the prevalence of hearing loss in US adults, NHANES 2003-2006

OBJECTIVE

This study aims to explore the association between coffee consumption and the prevalence of hearing loss in American adults based on a national population-based survey.

DESIGN

Cross-sectional analysis of reported audiometric status and coffee intake from the 2003-2006 National Health and Nutrition Examination Survey (NHANES). Multivariate logistic regression, forest plots and restricted cubic spline (RCS) analyses were used to explore the associations and dose-response relationships between coffee consumption frequency and hearing loss.

SETTING

The USA.

PARTICIPANT

This study included 1894 individuals aged ≥ 20 from the 2003-2006 NHANES.

RESULTS

In this study, the prevalence of speech-frequency hearing loss (SFHL) and high-frequency hearing loss (HFHL) among the participants was 35·90 % and 51·54 %, respectively. Compared with those who no consumed coffee, non-Hispanic White who consumed ≥ 4 cups/d had higher prevalence of SFHL (OR: 1·87; 95 % CI: 1·003. 3·47). And a positive trend of coffee consumption frequency with the prevalence of HFHL was found (Ptrend = 0·001). This association of HFHL was similar for participants aged 20-64 (Ptrend = 0·001), non-Hispanic White (Ptrend = 0·002), non-noise exposure participants (Ptrend = 0·03) and noise-exposed participants (Ptrend = 0·003). The forest plots analysis found that the association between 1 cup-increment of daily coffee consumption and the prevalence of HFHL was statistically significant in males. RCS model supported a positive linear association of coffee consumption with SFHL (P for overall association = 0·02, P for nonlinearity = 0·48) and a positive non-linear association of coffee consumption with HFHL (P for overall association = 0·001, P for nonlinearity = 0·001).

CONCLUSION

Our findings suggested that coffee consumption was associated with higher prevalence of hearing loss. Further cohort studies in larger population are needed to investigate these findings.

Dexamethasone treatment of murine auditory hair cells and cochlear explants attenuates tumor necrosis factor-α-initiated apoptotic damage

The most common cause of sensorineural hearing loss is damage of auditory hair cells. Tumor necrosis factor-alpha (TNF-α) is closely associated with sensorineural hearing loss. The present study examined the preconditioning effect of dexamethasone (DEX) on TNF-α-induced ototoxicity in mouse auditory hair cells (HEI-OC1) and cochlear explants. Treatment of HEI-OC1 with 10 ng/ml TNF-α for 24 h decreased cell viability, increased the accumulation of reactive oxygen species (ROS), and induced caspase-mediated apoptotic signaling pathways. Pretreatment with 10 nM DEX for 6 h before TNF-α exposure restored cell viability, decreased ROS accumulation, and attenuated apoptotic signaling activation induced by TNF-α. Incubation of cochlear explants with 20 ng/ml TNF-α for 24 h resulted in significant loss of both inner hair cells (IHCs) and outer hair cells (OHCs) and an increase in apoptotic activation accessed by annexin V staining. The cochlear explants pre-incubated with 10 nM DEX attenuated TNF-α ototoxicity in both IHCs and OHCs and apoptotic cell death. These results indicated that DEX plays a protective role in ototoxicity induced by TNF-α through attenuation of caspase-dependent apoptosis signaling pathway and ROS accumulation.

Mitigative effect of caffeine against diclofenac-induced hepato-renal damage and chromosomal aberrations in male albino rats

BACKGROUND

Among the most commonly consumed non-steroidal anti-inflammatory drugs (NSAID) is Diclofenac (Dic), especially in low-income countries due to its high efficiency and affordable price. However, the continuous administration of Diclofenac may induce toxic effects on various body organs including the liver and kidney. Caffeine (Caf) (1,3,7-trimethylxanthine) is a pharmacologically active alkaloid type with antioxidant and anti-inflammatory actions.

AIM

The current study aims to evaluate the ameliorative effect of Caffeine against Dic-induced hepato-renal toxicity and damage.

METHODS

Twenty-four male albino rats type were assigned randomly into four groups (n = 6): (Group 1): Control group, (Group 2): Six male rats were exposed to Dic 10 mg/kg intraperitoneally (I.P) for 28 days, (Group 3): Six male rats were exposed to Caf (15 mg/kg orally) for 28 days; (Groups 4): Six male rats were exposed to Dic (10 mg/kg, i.p) + Caf (15 mg/kg, orally) for 28 days. Histopathological study and various biological parameters were estimated among the four groups including hemoglobin (Hb%) red blood cells (RBCs), Hematocrit (HT%), total leucocyte count (WBCs), lipid peroxidation (LPO), glutathione peroxidase (GPx), alanine aminotransferase (ALT), aspartate aminotransferase (AST), urea, creatinine, tumor necrosis factor-α (TNF-α), and nitric oxide (NO).

RESULTS

The administration of Diclofenac resulted in significant deteriorations in the histopathological findings and estimated biological parameters. Whereas, daily Caffeine administration ameliorated Diclofenac-induced toxicity in the kidney and liver by three mechanisms including antioxidant, anti-inflammatory, and DNA damage inhibition.

CONCLUSION

The current study demonstrated the promising ameliorative and protective effects of Caffeine against Diclofenac-induced hepatic and renal injury.

Purinergic Signalling in the Cochlea

The mammalian cochlea is the sensory organ of hearing with a delicate, highly organised structure that supports unique operating mechanisms. ATP release from the secretory tissues of the cochlear lateral wall (stria vascularis) triggers numerous physiological responses by activating P2 receptors in sensory, supporting and neural tissues. Two families of P2 receptors, ATP-gated ion channels (P2X receptors) and G protein-coupled P2Y receptors, activate intracellular signalling pathways that regulate cochlear development, homeostasis, sensory transduction, auditory neurotransmission and response to stress. Of particular interest is a purinergic hearing adaptation, which reflects the critical role of the P2X₂ receptor in adaptive cochlear response to elevated sound levels. Other P2 receptors are involved in the maturation of neural processes and frequency selectivity refinement in the developing cochlea. Extracellular ATP signalling is regulated by a family of surface-located enzymes collectively known as "ectonucleotidases" that hydrolyse ATP to adenosine. Adenosine is a constitutive cell metabolite with an established role in tissue protection and regeneration. The differential activation of A₁ and A_2A adenosine receptors defines the cochlear response to injury caused by oxidative stress, inflammation, and activation of apoptotic pathways. A₁ receptor agonism, A_2A receptor antagonism, and increasing adenosine levels in cochlear fluids all represent promising therapeutic tools for cochlear rescue from injury and prevention of hearing loss.

G protein-coupled receptors in cochlea: Potential therapeutic targets for hearing loss

The prevalence of hearing loss-related diseases caused by different factors is increasing worldwide year by year. Currently, however, the patient’s hearing loss has not been effectively improved. Therefore, there is an urgent need to adopt new treatment measures and treatment techniques to help improve the therapeutic effect of hearing loss. G protein-coupled receptors (GPCRs), as crucial cell surface receptors, can widely participate in different physiological and pathological processes, particularly play an essential role in many disease occurrences and be served as promising therapeutic targets. However, no specific drugs on the market have been found to target the GPCRs of the cochlea. Interestingly, many recent studies have demonstrated that GPCRs can participate in various pathogenic process related to hearing loss in the cochlea including heredity, noise, ototoxic drugs, cochlear structure, and so on. In this review, we comprehensively summarize the functions of 53 GPCRs known in the cochlea and their relationships with hearing loss, and highlight the recent advances of new techniques used in cochlear study including cryo-EM, AI, GPCR drug screening, gene therapy vectors, and CRISPR editing technology, as well as discuss in depth the future direction of novel GPCR-based drug development and gene therapy for cochlear hearing loss. Collectively, this review is to facilitate basic and (pre-) clinical research in this area, and provide beneficial help for emerging GPCR-based cochlear therapies.

Effects of Combined Gentamicin and Furosemide Treatment on Cochlear Macrophages

Combining aminoglycosides and loop diuretics often serves as an effective ototoxic approach to deafen experimental animals. The treatment results in rapid hair cell loss with extended macrophage presence in the cochlea, creating a sterile inflammatory environment. Although the early recruitment of macrophages is typically neuroprotective, the delay in the resolution of macrophage activity can be a complication if the damaged cochlea is used as a model to study subsequent therapeutic strategies. Here, we applied a high dose combination of systemic gentamicin and furosemide in C57 BL/6 and CBA/CaJ mice and studied the ototoxic consequences in the cochlea, including hair cell survival, ribbon synaptic integrity, and macrophage activation up to 15-day posttreatment. The activity of macrophages in the basilar membrane was correlated to the severity of cochlear damage, particularly the hair cell damage. Comparatively, C57 BL/6 cochleae were more vulnerable to the ototoxic challenge with escalated macrophage activation. In addition, the ribbon synaptic deterioration was disproportionately limited when compared to the degree of outer hair cell loss in CBA/CaJ mice. The innate and differential otoprotection in CBA/CaJ mice appears to be associated with the rapid activation of cochlear macrophages and a certain level of synaptogenesis after the combined gentamicin and furosemide treatment.

Long-term auditory follow-up in the management of pediatric platinum-induced ototoxicity

PURPOSE

Irreversible bilateral sensorineural hearing loss is a common side effect of platinum compounds. Because of the extended overall survival, a prolonged hearing surveillance and management of hearing impairments are emerging concerns for pediatric oncology.

METHODS

In this retrospective observational study, we enrolled 38 children out of 116 treated at our institution by chemotherapy (cisplatin and/or carboplatin) with or without irradiation between 2007 and 2014, submitted to hearing monitoring before every cycle of chemotherapy, and who completed a 5-year long-term audiological follow-up. Chemotherapy regimens, demographic findings, cumulative doses, and cranial irradiation were compared.

RESULTS

At the end of 5-year follow-up, ototoxicity was significantly increased compared to that observed at the end of chemotherapy (52.5% vs 39.5%, p < 0.001). A late onset of hearing loss was experienced in 13.1% of children, while in 26.3% progressive hearing loss was measured. Deafness at the end of chemotherapy and irradiation were significant prognostic factors for late ototoxicity outcomes (Odds Ratio 7.2-CI 1.67-31.1-p < 0.01 and 5.25-CI 1.26-21.86-p < 0.01 respectively). No significant differences were found between cisplatin and combined treatment (i.e., cisplatin shifted to carboplatin during monitoring for the onset of ototoxicity) and ototoxicity was not associated with platinum compounds cumulative dose (p > 0.05). 13.1% of children needed hearing aids at the end of follow-up.

CONCLUSION

Long-term monitoring of at least 5 years prevents the harmful effects of hearing deprivation identifying late onset/progressive hearing loss after platinum compound chemotherapy in children thanks to early hearing rehabilitation, especially in those who underwent multimodal therapy or subjected to irradiation.

Urine caffeine metabolites and hearing threshold shifts in US adults: a cross-sectional study

Previous studies have reported the relationship between effect of caffeine and many diseases. However, studies to evaluate the association between caffeine and hearing loss are contradictory. To examine the relationship of urinary caffeine metabolites with the hearing threshold in US adults, a total of 849 adults aged 20–69 years who participated in the National Health and Nutrition Examination Survey (NHANES, 2011–2012) were enrolled in this study. Urinary caffeine and its 14 metabolites were applied as biomarkers to assess caffeine exposure. Hearing loss was defined as mean pure tone averages > 25 dB HL at 500, 1000, and 2000 Hz in both ears (low frequency); and 3000, 4000, and 6000 Hz in both ears (high frequency). Univariate and multivariate linear regression analyses were conducted to examine the associations of urinary caffeine metabolites with low- and high-frequency hearing thresholds, respectively. Low-frequency hearing loss were 5.08% and 6.10% in male and female participants, respectively; and high-frequency hearing loss were 31.81% and 15.14% in male and female participants, respectively. In the unadjusted model, the P value for trend shows that urinary caffeine metabolites 137X and AAMU were significantly associated with low-frequency PTA, and that 17X, 137X, AAMU were significantly associated with high-frequency PTA, but when the model was adjusted for sex, age, education level, firearm noise exposure, occupational noise exposure, recreational noise exposure, serum cotinine, body mass index, diabetes, hypertension, these were no longer statistically significant. In conclusion, urinary caffeine metabolites were not associated with the hearing threshold shifts in US adults.

A comprehensive review of the effects of caffeine on the auditory and vestibular systems

Coffee, of which caffeine is a critical component, is probably the most frequently used psychoactive stimulant in the world. The effects of caffeine on the auditory and vestibular system have been investigated under normal and pathological conditions, such as acoustic trauma, ototoxicity, auditory neuropathy, and vestibular disorders, using various tests. Lower incidences of hearing loss and tinnitus have been reported in coffee consumers. The stimulatory effect of caffeine is represented by either a shorter latency or enhanced amplitude in electrophysiological tests of the auditory system. Furthermore, in the vestibular system, oculomotor testing revealed significant effects of caffeine, while other tests did not reveal any significant caffeine effects. It could be that caffeine improves transmission in the auditory and vestibular systems' central pathways. Importantly, the effects of caffeine seem to be dose-dependent. Also, inconsistent findings have been observed regarding caffeine's effects on the auditory and vestibular systems and related disorders. Overall, these findings suggest that caffeine does not strongly influence the peripheral auditory and vestibular systems. Instead, caffeine's effects seem to occur almost solely at the level of the central nervous system.

Applicability of Cork as Novel Modifiers to Develop Electrochemical Sensor for Caffeine Determination

This study aims to investigate the applicability of a hybrid electrochemical sensor composed of cork and graphite (Gr) for detecting caffeine in aqueous solutions. Raw cork (RAC) and regranulated cork (RGC, obtained by thermal treatment of RAC with steam at 380 °C) were tested as modifiers. The results clearly showed that the cork-graphite sensors, GrRAC and GrRGC, exhibited a linear response over a wide range of caffeine concentration (5-1000 µM), with R² of 0.99 and 0.98, respectively. The limits of detection (LOD), estimated at 2.9 and 6.1 µM for GrRAC and GrRGC, suggest greater sensitivity and reproducibility than the unmodified conventional graphite sensor. The low-cost cork-graphite sensors were successfully applied in the determination of caffeine in soft drinks and pharmaceutical formulations, presenting well-defined current signals when analyzing real samples. When comparing electrochemical determinations and high performance liquid chromatography measurements, no significant differences were observed (mean accuracy 3.0%), highlighting the potential use of these sensors to determine caffeine in different samples.

Strategies to reduce the risk of platinum containing antineoplastic drug-induced ototoxicity

INTRODUCTION

Cisplatin is a highly effective chemotherapeutic agent against a variety of solid tumors in adults and in children. Unfortunately, a large percentage of patients suffer permanent sensorineural hearing loss. Up to 60% of children and at least 50% of adults suffer this complication that seriously compromises their quality of life. Hearing loss is due to damage to the sensory cells in the inner ear. The mechanisms of cochlear damage are still being investigated. However, it appears that inner ear damage is triggered by reactive oxygen species (ROS) formation and inflammation 34.

AREAS COVERED

We discuss a number of potential therapeutic targets that can be addressed to provide hearing protection. These strategies include enhancing the endogenous antioxidant pathways, heat shock proteins, G protein coupled receptors and counteracting ROS and reactive nitrogen species, and blocking pathways that produce inflammation, including TRPV1 and STAT1 36.

EXPERT OPINION

Numerous potential protective agents show promise in animal models by systemic or local administration. However, clinical trials have not shown much efficacy to date with the exception of sodium thiosulfate. There is an urgent need to discover safe and effective protective agents that do not interfere with the efficacy of cisplatin against tumors yet preserve hearing 151.

The dual role of curcumin and ferulic acid in counteracting chemoresistance and cisplatin-induced ototoxicity

Platinum-based agents, such as cisplatin, form the mainstay of currently used chemotherapeutic regimens for several malignancies; however, the main limitations are chemoresistance and ototoxic side effects. In this study we used two different polyphenols, curcumin and ferulic acid as adjuvant chemotherapeutics evaluating (1) in vivo their antioxidant effects in protecting against cisplatin ototoxicity and (2) in vitro the transcription factors involved in tumor progression and cisplatin resistance. We reported that both polyphenols show antioxidant and oto-protective activity in the cochlea by up-regulating Nrf-2/HO-1 pathway and downregulating p53 phosphorylation. However, only curcumin is able to influence inflammatory pathways counteracting NF-κB activation. In human cancer cells, curcumin converts the anti-oxidant effect into a pro-oxidant and anti-inflammatory one. Curcumin exerts permissive and chemosensitive properties by targeting the cisplatin chemoresistant factors Nrf-2, NF-κB and STAT-3 phosphorylation. Ferulic acid shows a biphasic response: it is pro-oxidant at lower concentrations and anti-oxidant at higher concentrations promoting chemoresistance. Thus, polyphenols, mainly curcumin, targeting ROS-modulated pathways may be a promising tool for cancer therapy. Thanks to their biphasic activity of antioxidant in normal cells undergoing stressful conditions and pro-oxidant in cancer cells, these polyphenols probably engage an interplay among the key factors Nrf-2, NF-κB, STAT-3 and p53.