The role of free oxygen radicals on the development of otitis media with effusion

Narrative Review of Free Radicals and Reactive Oxygen Species in Otitis Media

Many studies have evaluated the roles of free radicals and reactive oxygen species (ROS) in various diseases. To date, however, no systematic review has specifically investigated the involvement of free radicals and ROS in acute otitis media (OM), OM with effusion, and chronic OM. The present study therefore assessed the roles of free radicals and ROS in OM. SCOPUS, PubMed, Cochrane Library, EMBASE, and Google Scholar were comprehensively searched to identify studies assessing the roles of free radicals and ROS in OM. Relevant studies were identified and their findings summarized. The literature search identified 21 studies. A review of their findings showed that the concentrations of hydrogen peroxide (H2O2), lipid hydroperoxide (LPO), and myeloperoxidase (MPO) were elevated in patients with acute OM; that the concentrations of H2O2, LPO, MPO, xanthine oxidase (XO), superoxide dismutase (SOD), glutathione peroxidase (GPX), malondialdehyde (MDA), hydroxyl radical (·OH), and nitrotyrosine were elevated in patients with OM with effusion; and that the levels of nitric oxide (NO), MPO, 4-hydroxynonenal (4-HNE), and malondialdehyde (MDA) were elevated in patients with chronic OM. Although some studies reported that SOD levels were increased in patients with OM with effusion, decreases in antioxidants such as SOD and catalase, as well as total antioxidant capacity, were observed across all types of OM. Although the levels of free radicals and ROS varied by type of OM, study design, control group selection, sample type, ROS and free radical markers, and antioxidant types, most studies showed increased ROS and decreased antioxidants in OM patients. These findings suggest that levels of free radicals and ROS are strongly associated with the pathophysiology of OM.

A Preliminary Study on Acute Otitis Media in Spanish Children with Late Dinner Habits

The timing of caloric intake plays an important role in the long-term process that leads to communicable diseases. The primary objective of this study was to analyse whether children who ate dinner early were at lower risks of acute respiratory infections than children who ate dinner late during the COVID-19 pandemic.

METHODS

This cross-sectional study was conducted from July to December 2020 on children attending Majorcan emergency services. Our survey on dinner time habits was carried out by using self-administered questionnaires.

RESULTS

A total of 669 children were included in this study. The median dinner time was 8:30 pm. Late dinner eaters accounted for a higher proportion of acute otitis media (7% vs. 3%; p = 0.028) than early dinner eaters. Other infectious diseases were not associated with dinner time habits.

CONCLUSIONS

We make a preliminary estimate of the link between late dinner habits and acute otitis media in children. However, no conclusions about causality can be established due to the observational design of the study, and further research is needed in order to confirm the different issues raised by our initial exploration of an emerging research area.

Correlation between Serum Interleukin-17 level and Serum Reactive Oxygen Species levels among Children experiencing Otitis Media with Effusion

Introduction  The detection of inflammatory mediators in the serum of children with have otitis media with effusion (OME) and their correspondence with clinical considerations may enable the use of a modern nonsurgical curative treatment for OME.

Objective  To determine the relation between interleukin-17 (IL-17) serum level and reactive oxygen species (ROS) serum levels in children suffering from OME and to disclose if any variation occurs in the level of IL-17 Will affect the ROS and antioxidant equilibrium in the serum, which indicates the entire body's reaction to OME.

Methods  The present study was a case-control study. A total of 24 children experienced OME, and 24 healthy controls were recruited.

All participants in the study were subjected to a systematic clinical investigation including otoscopic, audiometric, and tympanometric examination. Also, venous blood samples were collected from all children to determine the levels of IL-17 and ROS.

Results  The mean ± standard deviation (SD) age ranges of the patients and the control group were 6.8 ± 2.7 and 6.2 ± 3.4 years, respectively. A stylistically significant difference in the levels of serum nitric oxide (NO), catalase (CT), myeloperoxidase (MPO), and malondialdehyde (MDA) ( p  < 0.05) was detected between OME and control patients. No significant difference was found in serum levels of superoxide dismutase (SOD) and glutathione peroxidase (GPX) between OME and control patients. The serum levels of MDA, NO, and MPO positively correlated with the serum levels of IL-17 in OME patients.

Conclusion  In the present study, there is a reasonable role of the IL-17 pathway in OME pathogenesis through an increase in ROS levels.

Plasma Selenium and Cadmium Levels in Patients with Chronic Otitis Media in a Turkish Population and Their Relation to Inflammation Markers

Chronic otitis media (COM) is a multifactorial process, for which a clear etiology has not yet been established. The aims of the present study were to evaluate selenium (Se) and cadmium (Cd) levels in patients with COM and to analyze the correlation between Se and Cd with inflammation markers. The study population consisted of 88 participants: 45 healthy controls (group 1) and 43 patients with COM (group 2). Demographic data, Se, Cd, C-reactive protein (CRP), and white blood cell count (WBC) levels were all recorded. Se and Cd measurements were performed in a graphite furnace atomic absorption spectrophotometer (Perkin Elmer Analyst 800) using Zeeman background correction. The Se and Cd levels were compared between the groups and the correlation between Se and Cd with inflammation markers was analyzed. No statistically significant difference was determined between the groups in terms of demographic data (p > 0.05). CRP and WBC levels were significantly higher in group 2 than in group 1 (p < 0.05). Se levels were significantly lower in group 2 than in group 1, at 23.40 ± 12.08 μg/L vs. 37.31 ± 22.44 μg/L (p < 0.05). Cd levels were significantly higher in group 2 than in group 1, at 1.79 ± 1.63 μg/L vs. 0.68 ± 0.45 μg/L (p < 0.05). When all the cases were evaluated together, a statistically significant negative correlation was determined between Se and CRP (r = - 0.239, p = 0.013) and a positive correlation between Cd and CRP (r = 0.266, p = 0.006), WBC (r = 0.258, p = 0.008). Our results could propose that Se deficiency and Cd excess could play a crucial and additive role in the etiopathogenesis of COM. However, further investigations with larger numbers of patients are warranted to determine the exact role of these elements.

Is otitis media with effusion associated with oxidative stress? Evaluation of thiol/disulfide homeostasis

BACKGROUND

We evaluated the relationship between otitis media with effusion and thiol/disulfide homeostasis using a novel marker of oxidative stress.

METHODS

The study group consisted of 30 patients (mean age 8.33 ± 3.30 years) with bilateral otitis media with effusion admitted to our hospital. The control group consisted of 35 (mean age 7.40 ± 3.97 years) age-, sex-, and body mass index-matched healthy subjects. Thiol/disulfide homeostasis was measured using a newly developed method.

RESULTS

Native and total thiol levels were lower in the study than the control group (native thiols 421.37 ± 72 μmol/L vs. 464.46 ± 46.42 μmol/L, p < 0.05; total thiols 468.42 ± 77.89 μmol/L vs. 501.32 ± 50.30 μmol/L, respectively). Disulfide levels and the disulfide/native thiol and disulfide/total thiol ratios were higher in the study group (disulfides 23.56 ± 4.68 μmol/L vs. 18.43 ± 4.94 μmol/L; disulfide/native thiol ratio 5.65 ± 1.05 vs. 3.97 ± 1.03%; disulfide/total thiol ratio 5.06 ± 0.83 vs. 3.66 ± 0.88%, respectively).

CONCLUSION

Oxidative stress may be the major cause of the increase in oxidized thiols in patients with bilateral otitis media with effusion, however, this relationship requires further investigation.

Oxidative stress in otosclerosis

OBJECTIVES

Otosclerosis is a disease involving abnormal bone turnover in the human otic capsule that results in hearing loss. Several hypotheses have been suggested for the etiopathogenesis of otosclerosis; however, its etiology remains unclear.

METHODS

This study evaluated the correlation between otosclerosis and levels of paraoxonase-1 (PON1), arylesterase, total antioxidant status, total oxidant status (TOS), oxidative stress index (OSI), total sulfhydryl (-SH) groups, lipid hydroperoxide, and ceruloplasmin in the serum of otosclerosis patients and healthy subjects with respect to oxidative stress.

RESULTS

In our study, TOS and OSI levels were higher in the otosclerosis patients than in the controls. The PON1 levels showed that oxidative stress was severe, and as a result, antioxidants were consumed and depleted.

DISCUSSION

When an imbalance between oxygen free radical production and antioxidative defense mechanisms occurs, reactive oxygen species levels may increase, which in turn may damage cells and tissues through the peroxidation of phospholipid membrane structures. The body initially responds with increased antioxidant production, but if the oxidative stress is severe, decreased antioxidant levels may result. This study reports expression levels of oxidative stress species in otosclerosis patients.

Anti-inflammatory and anti-oxidative effects of alpha-lipoic acid in experimentally induced acute otitis media

OBJECTIVES

To investigate the anti-inflammatory, anti-oxidative and tissue protective effects, as well as the potential therapeutic role, of alpha-lipoic acid in experimentally induced acute otitis media.

METHODS

Twenty-five guinea pigs were assigned to one of five groups: a control (non-otitis) group, and otitis-induced groups treated with saline, penicillin G, alpha-lipoic acid, or alpha-lipoic acid plus penicillin G. Tissue samples were histologically analysed, and oxidative parameters in tissue samples were measured and compared between groups.

RESULTS

The epithelial integrity was better preserved, and histological signs of inflammation and secretory metaplasia were decreased, in all groups compared to the saline treated otitis group. In the alpha-lipoic acid plus penicillin G treated otitis group, epithelial integrity was well preserved and histological findings of inflammation were significantly decreased compared to the saline, penicillin G and alpha-lipoic acid treated otitis groups. The most favourable oxidative parameters were observed in the control group, followed by the alpha-lipoic acid plus penicillin G treated otitis group.

CONCLUSION

Alpha-lipoic acid, with its antioxidant, anti-inflammatory and tissue protective properties, may decrease the clinical sequelae and morbidity associated with acute otitis media.

The evaluation of oxidative stress in the serum and tissue specimens of patients with chronic otitis media

Objectives

To underline the effect of oxidative stress in chronic otitis media with and without cholesteatoma and to compare the oxidative stress values in the serum and tissue specimens in these two forms.

Methods

The study included a total of 75 individuals, 35 cases with chronic otitis media (COM; 16 females and 19 males) and a healthy control group of 40 cases (20 females and 20 males). The COM patient group was comprised of 18 patients with cholesteatoma and 17 patients without cholesteatoma. All patients underwent mastoidectomy. Serum specimens were taken prior to surgery and diseased tissue specimens from the ear were obtained during surgery from all patients. Only serum specimens were taken from the healthy control cases. The malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GHPx) were measured in the serum and tissue samples of the patient group and in the serum specimens of the control group.

Results

The age ranged from 14 to 48 years in the patient group (mean age, 20.4±12.2 years) and from 19 to 40 years in the control group (mean age, 26.4±4.64 years). When the serum values of all COM patients were compared with those of the control group, in the patient group MDA, which reflects lipid peroxidation, was found to be significantly higher (P<0.01) whereas the antioxidant enzymes SOD, CAT, and GHPx were found to be significantly lower (P<0.01). When the serum and tissue MDA, SOD, CAT, and GHPx values in patients with and without cholesteatoma were compared, no significant difference was found these parameters (P>0.01).

Conclusion

Although oxidative stress plays a role in the pathogenesis of COM with or without cholesteatoma, it may not reflect the severity of the disease. In patients with COM, the evaluation of only serum oxidative stress values without tissue evaluation may be sufficient for assessing oxidative stress.

Advanced oxidation protein product level in children with chronic otitis media with effusion

OBJECTIVE

To determine the level of advanced oxidation protein products (AOPPs) in children with chronic otitis media with effusion (COME), in an effort to elucidate the multifactorial etiology of this disease.

METHODS

This study involved 25 COME patients and 30 healthy children (control group) recruited from the Ear, Nose and Throat (ENT) and Pediatric Departments, respectively, of the Haseki Research and Training Hospital. In the COME group, blood samples were collected before a middle ear operation, and middle ear fluid was sampled during the operation. Blood samples were also obtained from the control subjects. AOPP levels in the plasma and effusion fluid were measured by the spectrophotometric method.

RESULTS

In the COME group, the mean AOPP levels in plasma and effusion fluid were 168.08 μmol/l and 412.75 μmol/l, respectively. In the control group, the mean plasma AOPP level was 141.54 μmol/l. The plasma AOPP levels did not significantly differ between the COME and control groups (p>0.05). In the COME group, however, the effusion fluid AOPP level (412.75 ± 204.54 μmol/l) was significantly higher than the plasma AOPP level (168.08 ± 68.45 μmol/l; p<0.01).

CONCLUSION

We found that AOPP levels were elevated in the effusion fluid, but not in the plasma, of COME patients. Thus, COME was associated with protein oxidation abnormalities. Oxidative stress may play a role in the etiopathogenesis of COME, and AOPPs may be used as markers of oxidative stress; however, further studies are required to confirm these findings.

Is there a relationship between serum levels of vitamin a, vitamin e, copper and zinc and otitis media with effusion in children?

The aim of this study is to determine whether the serum levels of vitamin A, vitamin E, copper and zinc have a role in the development of otitis media with effusion (OME) in childhood. This prospective study was conducted between February 2010 and February 2011 at a tertiary Otorhinolaryngoloy Clinic. There were 113 subjects and subdivided into three groups. Group 1 consisted of 44 patients who underwent adenoidectomy with ventilation tube placement due to OME. Group 2 consisted of 43 patients underwent adenoidectomy alone and group 3,called control group, included 26 healthy children. Serum values of vitamin A, vitamin E, copper and zinc were measured preoperatively. Comparison of the patient groups showed that group 1 patients had significantly lower serum zinc levels than group 2 patients (p = 0.002), although differences between both patients groups and controls were not significant. We found that the differences among the three groups in terms of serum levels of vitamin A, vitamin E and copper were not statistically significant (p > 0.05). The results of this study showed that serum levels of vitamin A, vitamin E and copper may not play a role on development of OME. We postulated that high serum zinc status may have the preventive effect in the predisposition to OME which may related to adenoid hyperplasia.

Oxidative stress in chronic otitis media

Chronic otitis media usually presents with a benign tumor-like lesion of the temporal bone known as a cholesteatoma. The role of oxidative stress in the pathogenesis of chronic otitis media and cholesteatoma has not yet been fully explored. Therefore, the aim of this study was to investigate the oxidative stress markers and antioxidant enzymes in patients with cholesteatomatous and noncholesteatomatous chronic otitis media and in healthy subjects. A prospective controlled trial was performed on cholesteatomatous and noncholesteatomatous chronic otitis media patients in a tertiary referral center in a university hospital. A total of 75 subjects, including 25 cholesteatomatous and 25 noncholesteatomatous chronic otitis media patients and 25 healthy subjects participated in this study. Serum total oxidant status (TOS) and oxidative stress index (OSI) levels were significantly increased in the patient groups with or without cholesteatoma compared with the control group. Serum total antioxidant status (TAS) levels and Paraoxonase and arylesterase activity were significantly lower in the patient groups with or without cholesteatoma compared with the control group. Serum TOS and OSI levels were lower in the noncholesteatomatous group, whereas serum TAS levels were higher compared with the cholesteatomatous group. Serum arylesterase activity was significantly lower in the noncholesteatomatous group compared with the control group. The results of this study reveal that in cholesteatoma cases, the oxidative stress and antioxidant enzyme imbalance were more significant than in cases of chronic otitis media without cholesteatoma.

Effect of caffeic acid phenethyl ester (CAPE) on H₂O₂ induced oxidative and inflammatory responses in human middle ear epithelial cells

OBJECTIVE

Acute otitis media (OM) is a common pediatric disease. Recent research into the pathogenesis of OM has focused on oxidative damage, induced by oxygen free radicals, to the middle ear mucosa along with inflammation. Caffeic acid phenethyl ester (CAPE) is a biologically active ingredient of propolis honey bees, with antioxidative and anti-inflammatory activities. The effect of CAPE on hydrogen peroxide (H(2)O(2))-induced inflammatory and oxidative reactions in the middle ear is still not known. The aim of this study was to evaluate the anti-inflammatory and antioxidative effects of CAPE on cultured human middle ear epithelial cells (HMEECs).

METHODS

The inflammatory injury of H(2)O(2) and the anti-inflammatory effect of CAPE were determined by measuring levels of pro-inflammatory cytokines (tumor necrosis factor (TNF)-α and COX-2) with real-time reverse transcription polymerase chain reaction and Western blot analysis. Oxidative stress induced by H(2)O(2) and antioxidative effects of CAPE were evaluated directly by reactive oxygen species (ROS) production using flow cytometric analysis of 5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate, acetyl ester (CM-H(2)DCFDA), and indirectly by the expression of superoxide dismutase (SOD) using Western blot analysis. The effect of CAPE was compared with N-acetyl cysteine (NAC) which has well-known antioxidative and anti-inflammatory effects.

RESULTS

CAPE significantly inhibited H(2)O(2)-induced upregulation of TNF-α and COX-2 expression in a dose and time dependent manner. ROS accumulation induced by H(2)O(2) stimulation was decreased by CAPE pretreatment. Induced SOD expression after H(2)O(2) stimulation was diminished by CAPE pretreatment. The anti-inflammatory and antioxidative effects of CAPE were similar to those of NAC.

CONCLUSIONS

These findings suggest that inflammation induced by H(2)O(2) can be inhibited by CAPE via inhibition of the expression of pro-inflammatory cytokines such as TNF-α and COX-2. Furthermore, CAPE has antioxidative effects, which decreases the need for endogenous SOD expression.

Oxidative stress in chronic otitis media with effusion

CONCLUSIONS

The high oxidant levels in chronic otitis media with effusion (OME) observed in our research and the improvement seen in children with chronic OME after antioxidant treatment suggest that oxygen-derived free radicals play an important role in chronic OME.

OBJECTIVES

OME is a common pathologic condition characterized by nonpurulent fluid in the middle ear (ME) that leads to moderate conductive hearing loss and flat tympanogram. During OME inflammatory cells generate large amounts of superoxide radicals to improve bactericidal activity. Overproduction of oxygen-derived free radicals induces oxidative damage in humans. Glutathione (GSH) is one of the major components of the antioxidant system that protects cells from oxidative stress. The aim of the study was to evaluate oxidative stress in chronic OME by investigation of ME fluids collected during myringotomy.

METHODS

During myringotomy, fluid was collected from the ME to evaluate lipid peroxide levels in the effusion. Fifty-nine children with ME effusion without any resolution after repeated medical treatments were enrolled in the study.

RESULTS

Lipid peroxide levels in all samples were high (mean 11.5 nmole/million cells), similar to the values found in other chronic diseases. GSH might be employed during surgery while applying ventilation tubes and after surgery to prevent oxidative stress.

Antioxidant role of selenium in rats with experimental acute otitis media

The aim of this prospective experimental animal study was to determine whether selenium had a protective effect on oxidative stress in rats with acute otitis media, by measuring the alterations of antioxidant parameters and lipid peroxidation on days 4 and 10 after inoculation into the middle ear. Streptococcus pneumoniae was inoculated into the middle ear cavities of 32 rats in animal laboratory of a tertiary medical center. Group 1 served as the control group and the animals were administered 1.5 ml/day saline. Group 2 received 0.2 mg/kg/day oral selenium for 10 days. The blood samples of each group were obtained on post-inoculation days 4 and 10. The levels of thiobarbituric acid reactive substances, albumin, total sulphydryl, superoxide dismutase and glutathione peroxidase were investigated. Day 10 level of thiobarbituric acid reactive substance in group 2 was lower than the day 4 level of the same substance in the control group. Although glutathione peroxidase and superoxide dismutase levels significantly decreased starting from 4th day until 10th day in group 1, their levels increased in group 2. Day 10 levels of albumin and total sulphydryl in group 1 were significantly higher than day 4 levels in group 2. We found that selenium supplementation for 10 days decreased thiobarbituric acid reactive substances and increased glutathione peroxidase and superoxide dismutase levels when compared to the control group. We believe that selenium supplementation may be beneficial to prevent the clinical sequelae and recurrence of otitis media.