Tetramethylpyrazine Attenuates Radiation-Induced Ototoxicity in a Rat Model.

INTRODUCTION: Tetramethylpyrazine (TMP) is a chemical compound, which has been shown to possess numerous biological features such as anticoagulation, inhibition of platelet aggregation, anti-inflammation, capillary dilatation, improvement in microcirculation, and protection against reactive oxygen radicals. The aim of the present study was to investigate the protective effect of TMP against radiation-induced ototoxicity. MATERIALS AND METHODS: 40 rats were divided into four groups. The first group was irradiated for 5 days. The second group received a single dose of 140 mg/kg/day intraperitoneal TMP given to the rats 30 min before radiotherapy (RT) for 5 days. The third group received a single dose of 140 mg/kg/day i.p. TMP for 5 days, whereas the fourth group was administered saline. All rats underwent distortion product otoacoustic emission (DPOAE) and auditory brainstem response measurements before and after the application. The temporal bulla of animals was removed for immunohistopathological examination. RESULTS: Signal-noise ratio values were significantly decreased in the RT group for the frequencies of 2-32 kHz after RT (p < 0.05), whereas the difference was not significant in terms of pre- and posttreatment values for the other groups. Also in the RT group, the ABR thresholds were significantly increased after treatment. In H&E staining, the mean scores for outer hair cells (OHCs), stria vascularis (SV), and spiral ganglion (SG) injuries were significantly higher in RT and RT + TMP groups than in the other groups. The mean OHCs and SV injury scores were also significantly higher in the RT group than in the RT + TMP group (p < 0.05). The number of cochleas that showed cytoplasmic caspase-3 immunoreactivity in the OHC, SV, and SG was significantly higher in RT and RT + TMP groups than in the other groups. CONCLUSION: The findings of the present study suggest that TMP may have a therapeutic potential for preventing sensorineural hearing loss (SNHL) related to RT.

Novel Thioether-Bridged 2,6-Disubstituted and 2,5,6-Trisubstituted Imidazothiadiazole Analogues: Synthesis, Antiproliferative Activity, ADME, and Molecular Docking Studies.

In this study, starting from 2-amino-1,3,4-thiadiazole derivatives (3-5), a new series of 2,6-disubstituted (compounds 7-15) and 2,5,6-trisubstituted (compounds 16-33) imidazo[2,1-b][1,3,4]-thiadiazole derivatives were synthesized using cyclization and Mannich reaction mechanisms, respectively. All synthesized compounds were characterized by 1 H-NMR, 13 C-NMR, FT-IR, elemental analysis, and mass spectroscopy techniques. Also, X-ray diffraction analysis were used for compounds 4, 7, 11, 17, and 19. The cytotoxic effects of the new compounds on the viability of colon cancer cells (DLD-1), lung cancer cells (A549), and liver cancer cells (HepG2) were investigated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method in vitro. Compound 15 was found to be the most potent anticancer drug candidate in this series with an IC50 value of 3.63 µM against HepG2 for 48 h. Moreover, the absorption, distribution, metabolism, and excretion (ADME) parameters of the synthesized compounds were calculated and thus, their potential to be safe drugs was evaluated. Finally, to support the biological activity experiments, molecular docking studies of these compounds were carried out on three different target cancer protein structures (PDB IDs: 5ETY, 1M17, and 3GCW), and the amino acids that play key roles in the binding of the compounds to these proteins were determined.

Objective Evaluation of Smell and Taste Senses in COVID-19 Patients.

Objective: The severe acute respiratory syndrome-coronavirus-2 pandemic is one of the largest of the recent times and can cause many symptoms including smell and taste disorders. In the literature, smell disorders caused by coronavirus disease-2019 (COVID-19) have been reported within a wide range from 3.2% to 98.3%. A small number of these studies demonstrated smell and taste disorders through objective tests. Our aim in this study was to determine the prevalence of smell and taste disorders in hospitalized patients due to COVID-19 infection. Methods: The study was carried out with 100 patients who were positive for real-time polymerase chain reaction and treated at the Kayseri City Hospital, and 100 healthcare worker relatives. We used the Connecticut Chemosensory Clinical Research Center test to evaluate the sense of smell. Sense of taste was evaluated using four different standardized bottles of preparations, and the results were scored according to the patients' statements. Results: Patient (Group 1) and control (Group 2) groups were compared for age, gender, smell and taste disorders. There were 39 women and 61 men in the patient group, and 40 women and 60 men in the control group. Mean age was 50.2±1.37 (range 21-70) years in Group 1 and 47.6±1.25 (range 18-70) years in Group 2, and there was no significant difference between the two groups. While the rate of smell disorder was 80% in Group 1, we found this rate as 35% in Group 2. Taste disturbance was identified in 38 patients, of whom 16 had mild hypogeusia, 17 had moderate hypogeusia, four had severe hypogeusia, and one patient had ageusia. We found that taste disorder was 38% in Group 1 and 3% in Group 2. Conclusion: Smell and taste dysfunctions are very common symptoms in COVID-19 patients. The results obtained using objective test methods are higher than the rates obtained from patient statements.

Protective role of lycopene in experimental allergic rhinitis in rats.

OBJECTIVE: We investigate whether lycopene has a protective effect in an experimental rat model of allergic rhinitis. METHODS: Experimental animals (65 rats) were randomized to 7 groups (Sham-Control, Lycopene 10 mg/kg/day, Lycopene 20 mg/kg/day, Intranasal lycopene drops, Intranasal steroid, Corn oil, Allergic Rhinitis). Rats were sensitized by administering of ovalbumin intraperitoneally and intranasally. In addition to ovalbumin; lycopene, corn oil and steroids were given to the relevant groups. Nasal symptom scores of the rats were recorded throughout the study. At end of the study, after intracardiac blood sample collection, all rats were sacrificed, and nasal tissues were examined histopathologically. Serum total immunoglobulin E (IgE) and ovalbumin (OVA) specific IgE were studied from all rats before and after the study. RESULTS: There was a statistically significant increase (p < 0.05) in OVA specific IgE values measured before and after the study in all groups except the sham group. In serum total IgE values; there was a statistically significant increase after treatment in allergic rhinitis, corn oil, lycopene 10 mg and intranasal lycopene drops group, but other groups did not show any significant change. Histopathological study with hematoxylin-eosin staining and cyclooxygenase-2 (COX-2), matrix metalloproteinase-9 (MMP-9), vasoactive intestinal peptide (VIP) expression found that lycopene suppresses inflammation with both nasal administration and increased dose. Nasal symptom scores were observed to decrease significantly in all lycopene and steroid groups compared to allergic rihinits and corn groups. CONCLUSION: It was determined that lycopene were effective in the treatment of allergic rhinitis, and this effect was found to be stronger with increasing doses of lycopene.

Susceptibility of severe COVID-19 patients to rhino-orbital mucormycosis fungal infection in different clinical manifestations.

PURPOSE: To present the different clinical manifestations of rhino-orbital mucormycosis (ROM) co-infection in severe COVID-19 patients. STUDY DESIGN: Prospective observational clinical study METHODS: Among 32,814 patients hospitalized with the diagnosis of COVID-19 between March 2020 and December 2020 in our center, eleven microbiologically confirmed ROM co-infection cases in severe COVID-19 patients were evaluated. RESULTS: There were nine men and two women with a mean age of 73.1 ± 7.7 years. Eight patients had uncontrolled type 2 diabetes with a mean diagnosis duration of 12.1 ± 4.4 years. All patients had COVID-19-associated acute respiratory distress syndrome and received corticosteroids. The mean time interval between COVID-19 diagnosis and ROM diagnosis was 14.4 ± 4.3 days. Seven patients (63.6%) had orbital apex syndrome, and four patients (36.4%) presented with orbital cellulitis. Endophthalmitis was detected in 54.5% of patients, and two of these patients developed retinoschisis. CT scan/MRI revealed sino-orbital involvement in all patients, and three of these had cerebral involvement at initial presentation. All patients received intravenous and retrobulbar liposomal amphotericin B and had undergone radical debridement of involved sinuses. Intravitreal liposomal amphotericin B injected in patients with endophthalmitis. Despite all measures, 63.6% of patients expired. CONCLUSIONS: Severe COVID-19 is associated with a significant incidence of ROM with higher mortality rates due to immune dysregulation and the widespread use of steroids. Physicians should be aware of the possibility of this infection in patients with COVID-19. An aggressive multidisciplinary approach can help to reduce mortality.

Prognostic Value of Fibrinogen/HDL Ratio in Idiopathic Sudden Sensorineural Hearing Loss.

OBJECTIVES: Vascular causes are most frequently implicated in idiopathic sudden sensorineural hearing loss (ISSHL), and the process has been reported to be associated with fibrinogens and plasma lipoproteins. The purpose of this study was to determine the relationship between serum fibrinogen and high-density lipoprotein (HDL) levels, and the ratios of fibrinogen/HDL and monocyte/HDL, and ISSHL. MATERIALS AND METHODS: The present retrospective study included 116 patients with ISSHL. Treatment outcomes was categorised four groups according to Siegel's criteria as follows: complete recovery (Group1), partial recovery (Group 2), slight recovery (Group 3), or no improvement (Group 4). Fibrinogen, HDL and monocyte levels of patients were assessed through routine blood analyses, and fibrinogen/HDL and monocyte/HDL ratios were calculated for each patient. RESULTS: Fibrinogen values were significantly lower in Group 1 than in Groups 3 and 4, whereas the values were also significantly lower in Group 2 than in Group 3. HDL values in Group 1 were significantly higher than in the other groups. Fibrinogen/HDL values were significantly lower in Group 1 than in Groups 3 and 4. However, there was no significant difference among the groups with regard to monocyte/HDL ratios. CONCLUSION: To our knowledge, this is the first study investigating the fibrinogen/HDL ratio in ISSHL in the literature. Although fibrinogen/HDL ratio might be a useful prognostic indicator for hearing recovery in patients with ISSHL, further studies with a larger patient population is required to confirm its clinical practicability and reliability.

Secukinumab may be remedy for systemic amyloidosis findings secondary to hidradenitis suppurativa.

Hidradenitis suppurativa (HS) is a chronic relapsing inflammatory disease of follicular epithelium; many comorbidities occur that disrupt the quality of life of patients. Amyloidosis is one of them. We present a case with systemic amyloidosis secondary to HS and responding positively to secukinumab therapy. Secukinumab may also be an important option for amyloidosis findings in HS patients.

The prognostic and predictive value of platelet parameters in diabetic and nondiabetic patients with sudden sensorineural hearing loss.

BACKGROUND: We aimed to evaluate the association between mean platelet volume, platelet distribution width (PDW), platelet count (PC) and plateletcrit (PCT), and the presence of sudden sensorineural hearing loss (SSNHL) and treatment response. In the literature, there is no study that investigates the platelet functions in diabetic patients with SSNHL. METHODS: The patients were retrospectively assigned into Group 1 (68 diabetic patients with SSNHL), Group 2 (63 nondiabetic patients with SSNHL) and Group 3 (64 healthy controls). RESULTS: PC was not significantly different between the groups (p > 0.05). MPV, PDW and PCT values were significantly higher in Group 1 as compared to Groups 2 and 3 (p < 0.05). Platelet parameters were not significantly different between the patients who were responsive and nonresponsive to the treatment. Therefore, the platelet parameters did not affect prognosis significantly in this study samples (p > 0.05). CONCLUSIONS: This study showed that platelet parameters did not have a significant effect as a prognostic and predictive value in diabetic and nondiabetic patients with SSNHL. Further studies with more homogenous and larger study groups investigating the platelet parameters are needed to demonstrate microvascular damage and vascular alterations induced by diabetes mellitus.

Evaluation of Liver Functions Based on Serum Aminotransferase Enzyme Levels in Patients with Obstructive Sleep Apnea Syndrome.

Obstructive sleep apnea syndrome (OSAS) is associated with fatty liver disease. In the present study, relations between alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels and the severity of OSAS and polysomnography parameters were investigated. The study included 194 patients with OSAS and 114 control patients. The patients underwent an overnight polysomnography (PSG) in the Sleep Laboratory. ALT and AST levels were compared between the patients and the controls and between the subgroups of the patients. ALT and AST levels were also compared with the PSG parameters REM AHI, NREM AHI and minimum O2 saturation separately. The mean ALT was 28.95 in the patients and 17.85 in the controls (p < 0.001) with a statistically significant difference and the mean AST was 23.62 in the patients and 16.53 in the controls with a statistically significant difference (p < 0.001). The patients with OSAS had significantly higher ALT and AST levels. The higher the ALT and AST levels were, the more severe the disease was, though the differences between the subgroups of the patients were not significant.

Childhood Nasal Foreign Bodies: Analysis of 1724 Cases.

OBJECTIVE: This study evaluates the characteristics of the foreign bodies removed from the nose, the treatment methods used, and the complications associated with the foreign body, and discusses the reports in the literature. METHODS: Age, gender, type of foreign body, side of nose, clinical symptoms, complaints, diagnosis and treatment methods were retrospectively evaluated in all 1724 pediatric patients with foreign bodies. RESULTS: Of the 1724 patients, 841 (48.7%) were female and 883 (51.3%) were male. Their mean age was 4.3±3.06 years (age range: 4 months-16 years). Foreign body was found on the right side in 928 (53.8%), on the left-side in 768 (44.5%) and bilaterally in 28 (1.6%) patients. The foreign bodies were inorganic substances such as beads, paper, napkins, toy parts, batteries, pencils, erasers in 1287 cases (74.7%) and organic materials such as hazelnuts, walnuts and fruit seeds in 437 cases (25.3%). The foreign bodies were extracted in outpatient settings in 1709 cases. Fifteen patients in whom the foreign body was located in the posterior region and/or who were uncooperative were treated under anesthesia. The most common complication was epistaxis. Septal perforation was seen in one patient with alkaline battery. CONCLUSION: In pediatric patients presented to the otolaryngology and the pediatrics clinics with complaints involving nasal obstruction, unilateral purulent nasal discharge, epistaxis, and foul odor, possibility of a foreign body in the nose should be kept in mind.

Epithelial-myoepithelial carcinoma of the supraclavicular region: An unusual cause of dyspnea.

Epithelial-myoepithelial carcinoma (EMC) is an extremely rare disease and usually develops in major salivary glands, such as the parotid gland. EMC is regarded as a low grade-malignancy tumor, and the treatment protocol involves wide surgical excision with secure clear margins although postoperative radiotherapy is generally performed to reduce local recurrence. The present study aims to report a case of EMC with a supraclavicular location due to its rare occurrence and atypical location.

Decreased disulphide/thiol ratio in patients with autosomal recessive non-syndromic hearing loss.

INTRODUCTION: Oxidative stress plays a key role in the formation of age-related, noise-induced and drug-induced hearing loss. Thiols are organic compounds which can react with free radicals to protect against tissue and cell damage caused by reactive oxygen. There are no studies in literature on the association between autosomal recessive non-syndromic hearing loss(ARNSHL) including GJB2 and non-GJB2 mutations and thiol-disulphide balance. In this study, we aim to assess whether thiol-disulphide balance is disrupted in patients with ARNSHL. METHODS: Thirty-one ARNSHL patients and thirty-one healthy controls were included in this study. Patients whose parents were first degree cousins and who had at least two congenital hearing loss in the same family were included in the study. Audiological tests included air - bone pure tone audiometry and auditory brain stem response. GJB2 gene analysis was performed using sanger sequence method. Tests of thiol/disulphide homeostasis were conducted using the automated spectrophotometric method. We first investigated whether there was a significant difference between ARNSHL patients and healthy controls. Then, in order to determine the differential effect of the GJB2 gene mutations and non-GJB2 gene mutations on the thiol-disulphide balance, subjects were divided into three groups: Group 1 included patients with GJB2 mutations; Group 2 included patients with non-GJB2 mutations; Group 3 included healthy subjects. RESULTS: Patients with ARNSHL had significantly higher native thiol (411.6 ±â€¯54.3 µmol/l vs. 368.0 ±â€¯64.3 µmol/l, p = 0.006), total thiol levels (440.3 ±â€¯56.2 µmol/l vs. 402.4 ±â€¯65.9 µmol/l, p = 0.018), and lower disulphide levels (14.3 ±â€¯5.7 µmol/l) vs. (17.1 ±â€¯4.9 µmol/l), (p = 0.043) compared to the control group. Moreover, disulphide /native thiol (p < 0.001) and disulphide/total thiol (p < 0.001) were also detected lower in the ARNSHL group compared to the control group. Thiol-disulphide hemostasis parameters between all three groups showed that the native thiol and total thiol were increased in the Group 1 and Group 2. The disulphide levels decreased in Group 1 and 2, although not statistically significant. CONCLUSION: It was shown that thiol levels increased and disulphide levels decreased in patients with autosomal recessive non-syndromic hearing loss. It also may suggest that there is a reverse association between ARNSHL and oxidative stress. Further studies are needed on whether or not ARNSHL cause oxidative stress limited to the inner ear and cochlea.

An Unusual Bullet Trajectory: Entered Through the Face and Ended Up in the Neck.

The authors describe a case of gunshot injury in a 26-year-old male patient with an unusual bullet trajectory. The bullet had an entry hole just near the right lateral alar cartilage of the nose, and the trajectory descended through the left side of the neck by route of the hard palate, soft palate, and posterior pharyngeal wall, respectively. Surgical removal of the bullet was achieved with neck exploration. Gunshot injuries of the head and neck necessitate a thorough clinical and radiological evaluation due to the possibility of an unusual bullet trajectory.

Effects of isotretinoin on the olfactory function in patients with acne.

BACKGROUND:: Isotretinoin is a synthetic analog of vitamin A. Recent studies support a role for retinoic acid in the recovery of olfactory function following injury in mice. OBJECTIVE:: This study aimed at determining the effect of isotretinoin on olfactory function in patients who have acne and are otherwise healthy. METHODS:: Forty-five patients (aged 25-40 years) with acne were included in the study. All patients underwent a rhinological examination. Olfactory function was assessed by the Sniffin' Sticks Test. The test was assessed at baseline and in the third month of isotretinoin treatment. RESULTS:: Isotretinoin improved the performance of patients in the olfactory test. The SST score increased from 8.7±1.09 to 9.5±1.19 (p<0.001), prevalence of hyposmia decreased from 40% to 24% and normosmia increased from 60% to 75% (p=0.059). The percentage of patients whose olfactory function was categorized as "good" increased from 6% to 21.3%. This increase was statistically significant (p<0.05). STUDY LIMITATIONS:: Absence of a control group is one of the limitations of this study. Also, we did not evaluate patients with smell test after stopping isotretinoin treatment. CONCLUSION:: We examined the effect of systemic isotretinoin on olfactory function. It can be concluded from the present investigation that isotretinoin therapy improves the sense of smell.

Protective role of misoprostol in prevention of gentamicin ototoxicity.

OBJECTIVES: To demonstrate potential protective effect of misoprostol on cochlear toxicity caused by gentamicin with electrophysiological tests and histopathological studies. MATERIALS AND METHODS: The study included 80 ears of 40 rats with normal hearing threshold and DPOAE value in both ears. Animals were assigned into 4 groups. The rats were randomized into 4 groups. Group I (n = 10): Gentamicin, Group II (n = 10): Gentamicin plus misoprostol, Group III (n = 10): Saline; Group IV (n = 10): Misoprostol. All drugs used in the study were given once daily for 15 days. DPOAE and ABR measurements were repeated after drug administration. Subsequently, the rats' cochleae were examined histopathologically. Baseline DPOAE and ABR values were compared to those obtained after drug exposure and cochlear toxicity was evaluated in electrophysiological manner. RESULTS: When At baseline, there were no significant differences in DPOAE responses at frequencies of 1001, 1501, 2002, 3003, 4004, 6006 and 7996 Hz among groups. However In DPOAE test, statistically significant difference was observed between the pre-study basal values and post-study results in groups other than gentamicin + misoprostol group. Additionally, It was found that there was a significant difference in DPOAE response at frequency of 4004 Hz obtained at baseline and after drug exposure according to measurements of epithelial vacuolization in stria vascularis. While ABR threshold values were compared at baseline, there were no significant difference in ABR threshold values of left and right ear between groups. Histopathologically it was also found that there were significant differences measurements of epithelial vacuolization in stria vascularis and inflammation among groups (p < 0.05). CONCLUSION: By these results, misoprostol, a potent antioxidant, has protective effect against cochlear damage, and that may be a safe alternative.

Effects of isotretinoin on the olfactory function in patients with acne

Abstract: Background: Isotretinoin is a synthetic analog of vitamin A. Recent studies support a role for retinoic acid in the recovery of olfactory function following injury in mice. Objective: This study aimed at determining the effect of isotretinoin on olfactory function in patients who have acne and are otherwise healthy. Methods: Forty-five patients (aged 25-40 years) with acne were included in the study. All patients underwent a rhinological examination. Olfactory function was assessed by the Sniffin' Sticks Test. The test was assessed at baseline and in the third month of isotretinoin treatment. Results: Isotretinoin improved the performance of patients in the olfactory test. The SST score increased from 8.7±1.09 to 9.5±1.19 (p<0.001), prevalence of hyposmia decreased from 40% to 24% and normosmia increased from 60% to 75% (p=0.059). The percentage of patients whose olfactory function was categorized as "good" increased from 6% to 21.3%. This increase was statistically significant (p<0.05). Study limitations: Absence of a control group is one of the limitations of this study. Also, we did not evaluate patients with smell test after stopping isotretinoin treatment. Conclusion: We examined the effect of systemic isotretinoin on olfactory function. It can be concluded from the present investigation that isotretinoin therapy improves the sense of smell.

The protective role of tetramethylpyrazine against cisplatin-induced ototoxicity.

OBJECTIVES: The aim of the present study was to investigate the protective effect of tetramethylpyrazine (TMP) on cisplatin-induced ototoxicity in rats. METHODS: Forty healthy, female, 24-week-old, Sprague-Dawley rats (n = 40) were randomly assigned to four groups as follows: group one (n = 10) received intraperitoneal (i.p.) physiological saline at daily doses of 3 mg/kg for seven days; group two (n = 10) received a single dose of i.p. 15 mg/kg cisplatin; group three (n = 10) received i.p. 140 mg/kg TMP daily for seven days plus a single dose of i.p. 15 mg/kg cisplatin on the fourth day; group four (n = 10) received i.p. 140 mg/kg TMP daily for seven days. Auditory brainstem response (ABR) and distortion product otoacoustic emission (DPOAE) measurements were obtained from the animals (40 rats, 80 ears) under general anesthesia before and after drug administration. The temporal bulla of animals were bilaterally removed for immunohistopathological examination. RESULTS: In group two, DPOAE and ABR values were significantly deteriorated after drug administration, whereas there was no statistically significant difference between the pre- and posttreatment DPOAE and ABR values for all frequencies for groups one, three and four. The mean scores for external ciliated cells (ECCs), stria vascularis (SV) and spiral ganglion (SG) injuries in hematoxylin and eosin (H&E) staining, and also caspase-3 immunoreactivity were significantly higher in group two than in the other groups. CONCLUSION: In the present study, the protective effect of TMP on cisplatin ototoxicity was demonstrated through studies of electrophysiology and immunohistopathology. Co-administration of TMP may have potential protective effects against cisplatin-induced ototoxicity.

Potential Curative Role of Hypericum Perforatum in an Experimental Rat Model of Tympanic Membrane Perforation.

OBJECTIVE: Our aim was to investigate the curative role of topical Hypericum perforatum (HP) in a rat model of tympanic membrane perforation in a histopathological manner. MATERIALS AND METHODS: This study was conducted on 30 female Sprague-Dawley rats. An HP extract was prepared as a suspension in pure olive oil. In all rats, the right and left tympanic membranes were perforated by a fine puncture under a microscope. Rats were randomly assigned to three groups. The HP extract was given as drops on a daily basis in Group 1, while olive oil alone was given on a daily basis in Group 2. In Group 3, the rats were allowed spontaneous recovery without any intervention. Three rats from each group were sacrificed on days 7, 14, and 21. Temporal bullae were removed for histopathological examination to evaluate fibroblast proliferation, leukocyte infiltration, neovascularization, and subepithelial thickness and to compare these among the groups. RESULTS: In histopathological examination of the rats from each group on days 7, 14, and 21, there were significant differences in leukocyte infiltration, fibroblast proliferation, and subepithelial thickness. No significant difference was observed in neovascularization among the groups. CONCLUSION: Compared with the spontaneous recovery group, HP was found to be more effective in a wound-healing model of the tympanic membrane. HP may be applied in clinical practice if it is shown to be safe with regard to ototoxicity.

Effects of propolis in an experimental rat model of allergic rhinitis.

PURPOSE: The aim of this study was to determine the anti-allergic activity of propolis in an ovalbumin-induced rat model of allergic rhinitis. MATERIALS AND METHODS: This prospective experimental study was conducted at Hakan Çetinsaya Clinical and Experimental Animal Research Center with 30 rats. After sensitization of all rats with 0.3mg intraperitoneal ovalbumin plus 30mg aluminum hydroxide for 14days (first phase), rats were divided to five groups. In the second phase of the study 10µL of ovalbumin was applied to each nostril for 21days. Together with second phase, ketotifen (n:6), oral propolis (n:6), intranasal propolis (n:6) and intranasal mometasone furoate (n:6) were given to rats. A control group (n:4)(salin) and sham group (n:2) were planned. Symptoms were assessed on days 19, 22, 25, 30 and 35, resulting in 5 symptom scores: symptom scores 1-5. On day 35, nasal tissue was removed and histological examination was performed. RESULTS: When rats that received systemic and intranasal propolis were compared to controls, ciliary loss, inflammation, increase in goblet cells, vascular proliferation, eosinophil count, chondrocytes and allergic rhinitis symptom score were found to be decreased (p<0.05). CONCLUSIONS: It was found that propolis had anti-allergic effects on allergic symptom scores and nasal histology.