Investigation of the effect of pancreatic decellularized matrix on encapsulated Islets of Langerhans with mesenchymal stem cells.

OBJECTIVE: In this study, it was aimed to provide a therapeutic approach for T1DM by encapsulating the pancreatic islets with mesenchymal stem cells and decellularized pancreatic extracellular matrix to support the survival of islets while maintaining their cellular activity. METHOD: Pancreatic extracellular matrix was decellularized using different concentrations of detergent series. After the preparation of the protein-based tissue extracellular matrix was shown to be free of cells or any genetic material by molecular, immunofluorescence and histochemical techniques. Following the homogenization of the decellularized pancreatic extracellular matrix and the analysis of its protein composition by LC-MS, the matrix proteins were incorporated with pancreatic islets and rat adipose tissue-derived MSCs (rAT-MSCs) in alginate microcapsules. Glucose-stimulated insulin secretion property of the islet cells in the microbeads was evaluated by insulin ELISA. The gene expression profile of the encapsulated cells was analyzed by Real-Time PCR. RESULTS: Unlike the protein composition of whole pancreatic tissue, the decellularized pancreas matrix was free of histone proteins or proteins originated from mitochondria. The protein matrix derived from pancreatic tissue was shown to support the growth and maintenance of the islet cells. When compared to the non-encapsulated pancreatic islet, the encapsulated cells demonstrate to be more efficient in terms of insulin expression. CONCLUSION: The extracellular pancreatic matrix obtained in this study was directly used as supplementary in the alginate-based microcapsule enhancing the cell survival. The tissue matrix protein and alginate had a synergistic effect on total insulin secretion, which might have the potential to overcome the insulin deficiency. Despite the improvement in the cell viability and the number, the efficiency of the insulin secretion in response to glucose stimulation from the alginate microcapsules did not meet the expectation when compared with the non-encapsulated pancreatic islets.

Complementary and alternative medicine use in patients with mental disorders in Turkey.

PURPOSE: The aim of this study was to determine the prevalence of complementary and alternative medicine (CAM) use and the associated socio-demographic factors among patients with mental disorders in the Turkish community. METHODS: One thousand and twenty-seven patients with a diagnosis of mental disorders who were attending psychiatric outpatient clinics in five Turkish cities were interviewed. A survey questionnaire, which included questions on socio-demographic characteristics and CAM use, was administered face-to-face by psychiatrists. RESULTS: 22.2% of patients with mental disorders were using some form of CAM in the Turkish community. CAM and medication concurrent users had a higher level of education and income compared to CAM users only or medicine users only (p < 0.001). The most common type of CAM used was herbal therapy (n = 146, 64%). CONCLUSION: Use of CAM by patients with mental disorders should be investigated and taken into account by psychiatrists.

Effect of serum selenium levels on radiotherapy-related toxicity in patients undergoing radiotherapy for head and neck cancer.

AIM: To investigate whether there is a difference in selenium levels before and after radiotherapy (RT) and to study the effects of serum selenium levels on RT-related toxicity in patients undergoing RT for head and neck cancer. PATIENTS AND METHODS: A population of 47 consecutive patients was enrolled in the study. RT was given by conventional fractionation. RT-related acute toxicity was evaluated once a week. Blood samples were obtained before and after RT to evaluate selenium levels. RESULTS: There was no significant difference between the levels of selenium before and after RT (58.09 ± 1.36 µg/l and 56.34 ± 1.11 µg/l, p-value=0.747, respectively). Grade III-IV mucositis, dysphagia, radiodermatitis, and nausea were seen in 6 (12.7%), 32 (68.2%), 24 (51.1%), and 3 (6.4%) patients, respectively. It was found that there was no statistically significant difference in the levels of selenium before and after RT, and no observed differences in regard to RT-related toxicities. CONCLUSION: The serum selenium levels do not affect RT-related toxicities.

Ozone therapy and hyperbaric oxygen treatment in lung injury in septic rats.

Various therapeutic protocols were used for the management of sepsis including hyperbaric oxygen (HBO) therapy. It has been shown that ozone therapy (OT) reduced inflammation in several entities and exhibits some similarity with HBO in regard to mechanisms of action. We designed a study to evaluate the efficacy of OT in an experimental rat model of sepsis to compare with HBO. Male Wistar rats were divided into sham, sepsis+cefepime, sepsis+cefepime+HBO, and sepsis+cefepime+OT groups. Sepsis was induced by an intraperitoneal injection of Escherichia coli; HBO was administered twice daily; OT was set as intraperitoneal injections once a day. The treatments were continued for 5 days after the induction of sepsis. At the end of experiment, the lung tissues and blood samples were harvested for biochemical and histological analysis. Myeloperoxidase activities and oxidative stress parameters, and serum proinflammatory cytokine levels, IL-1ß and TNF-α, were found to be ameliorated by the adjuvant use of HBO and OT in the lung tissue when compared with the antibiotherapy only group. Histologic evaluation of the lung tissue samples confirmed the biochemical outcome. Our data presented that both HBO and OT reduced inflammation and injury in the septic rats' lungs; a greater benefit was obtained for OT. The current study demonstrated that the administration of OT as well as HBO as adjuvant therapy may support antibiotherapy in protecting the lung against septic injury. HBO and OT reduced tissue oxidative stress, regulated the systemic inflammatory response, and abated cellular infiltration to the lung demonstrated by findings of MPO activity and histopathologic examination. These findings indicated that OT tended to be more effective than HBO, in particular regarding serum IL-1ß, lung GSH-Px and histologic outcome.

Awareness, knowledge, and use of folic acid among women: a study from Turkey.

PURPOSE: To investigate the awareness, knowledge, and behaviors relevant to folic acid intake in women aged 15-49 years. MATERIALS AND METHODS: A questionnaire designed by the researchers was administered to 1,083 women who attended to family health care centers for any reason, between 1 and 15 of December 2009. RESULTS: Half of the women (53.7%) surveyed did not hear or read about folic acid. Women older than 35 and less-educated women were more unaware of folic acid. Out of 171 pregnant women, 81.3% (139 women) were taking/took vitamin/folic acid supplementation but only 12.2% of the users started to take supplements at least 1 month before conception. Out of 912 non-pregnant women 81 (8.9%) said they are taking any vitamin or mineral supplement. Out of the women who are not pregnant, not using a modern contraceptive method and planning to have a child at the time of the survey, only 9 (10%) were taking vitamin/folic acid. The most common information sources on folic acid were the doctors. CONCLUSION: In order to improve the intake of folic acid during the recommended period, preconceptional counseling by the family doctors to inform women of childbearing age about the need to take folic acid to prevent NTDs seems to be important.

The effect of grape seed extract on radiation-induced oxidative stress in the rat liver.

BACKGROUND/AIMS: The tolerance of the liver is considerably low when an effective radiation (RTx) dose needs to be delivered in patients in whom either their liver or whole body area has to be irradiated. The aim of this study was to evaluate the possible protective effect of grape seed extract on liver toxicity induced by RTx in the rat liver. METHODS: We used four groups, each consisting of 12 healthy male Wistar rats. RTx-grape seed extract group: rats were given grape seed extract (100 mg/kg) orally for seven days, following 8 Gy whole body irradiation, and grape seed extract was maintained for four days. RTx group: the same protocol was applied in this group; however, they received distilled water instead of grape seed extract. Grape seed extract group: only grape seed extract solution was administered for 11 consecutive days in the same fashion. CONTROL GROUP: only distilled water (orally) was administered in a similar manner. The level of malondialdehyde, an end product of lipid peroxidation, and the activities of superoxide dismutase and catalase, two important endogenous antioxidants, were evaluated in tissue homogenates. RESULTS: Grape seed extract was seen to protect the cellular membrane from oxidative damage and consequently from protein and lipid oxidation. In the RTx group, malondialdehyde levels were extremely higher than those of the grape seed extract-RTx group (p<0.001). Grape seed extract administration moderately reserved the malondialdehyde levels. RTx therapy decreased superoxide dismutase and catalase activities in the liver homogenates (p<0.001), and these alterations were significantly reversed by grape seed extract treatment (p<0.001). There were no differences between the grape seed extract- RTx, grape seed extract and control groups with regard to antioxidant activity (p>0.05). CONCLUSIONS: The levels of antioxidant parameters on RTx-induced liver toxicity were restored to control values with grape seed extract therapy. Grape seed extract may be promising as a therapeutic option in RTx-induced oxidative stress in the rat liver.

Role of grape seed extract on methotrexate induced oxidative stress in rat liver.

UNLABELLED: The efficacy of methotrexate (MTX), a widely used cytotoxic chemotherapeutic agent, is often limited by its severe hepatotoxicity. Regarding the mechanisms of these adverse effects, several hypotheses have been put forward, among which oxidative stress is noticeable. The present study was undertaken to determine whether grape seed extract (GSE), a new natural free radical scavenger, could ameliorate the MTX-induced oxidative injury in the rat liver. The animals were divided into 3 groups. Each group consisted of 12 animals. MTX-GSE group: rats were given GSE (100mg/kg body weight) orally for 15 days, and a single dose of MTX (20 mg/kg, intraperitoneally) was added on the 10th day. MTX group: these received placebo distilled water (orally) instead of GSE for 15 days and the same MTX protocol applied to this group on the 10th day. CONTROL GROUP: rats were given distilled water (orally) through 15 days and physiological saline (intraperitoneally) instead of MTX was administered on the 10th day in a similar manner. On the 16th day, liver tissue samples were obtained under deep anaesthesia. The level of malondialdehyde (MDA), an end product of lipid peroxidation, and the activities of süperoxide dismutase (SOD) and catalase (CAT), two important endogenous antioxidants, were evaluated in the tissue homogenates. MTX administration increased the MDA level and decreased the SOD and CAT activities in the liver homogenates (p < 0.001), while these alterations were significantly reversed by GSE treatment (p < 0.001). MTX led to significantly reduced whole blood count parameters (p < 0.05). When GSE was supplemented, no significant changes in blood count parameters were noted. It appears that GSE protects the rat liver and inhibits methotrexate-induced oxidative stress. These data indicate that GSE may be of therapeutic benefit when used with MTX.

Results of combination therapy with amifostine, pentoxifylline, ciprofloxacin and dexamethasone in patients with myelodysplastic syndrome and acute myeloid leukemia.

Myelodysplastic syndrome (MDS) is a clonal disease of the bone marrow characterized by abnormal hematopoiesis and cytopenias. It has been shown that abnormal cytokine production together with apoptosis are major contributors to the cytopenias associated with the disorder. As the interaction of cytokines plays a role in the pathogenesis, suppression of the cytokine production by the administration of the combination of pentoxifylline, ciprofloxacin, and dexamethasone (PCD combination) has resulted in the correction of at least some aspects of the cytopenias in the majority of patients and in complete hematologic remission in a small percentage. The aminothiol prodrug amifostine, a compound to protect tissues from cytotoxic drugs and radiotherapy has been found to stimulate proliferation of normal hematopoiesis and suppress apoptosis in patients with MDS. In this study we report the results of combination therapy of amifostine and PCD in 12 patients with MDS and acute myeloid leukemia (AML). Amifostine was given in a dose of 200 mg/m(2), as an i.v. infusion administered in 10 min, three times a week; pentoxifylline 2400 mg/day, (3 x 800 mg) p.o.; ciprofloxacin, 1 g/day p.o.; dexamethasone 4.5 mg/day p.o. We achieved 66% response rate in our patients. In some cases responses were achieved in only thrombocytopenia or anemia whereas in others responses were achieved in multiple series. As a result it was found that amifostine + PCD combination may be beneficial in reversing cytopenias in the treatment of MDS and AML and is worth further study.

Activity of propolis in an experimental model of pneumocystosis.

OBJECTIVE: To investigate the anti Pneumocystis effects of propolis on Pneumocystis carinii P. carinii in rat model. METHODS: Rats were obtained, and the study was taken in to place in Erciyes University Clinical and Experimental Research Center, Kayseri, Turkey, in June 2007. In order to obtain spontaneous pneumonia, rats were remained on immunosuppression therapy with dexamethasone throughout the study. Propolis administered orally at doses of 30, 50, and 100 mg/kg/day. Trimethoprim-sulfamethoxazole (TMP-SMX, 50/250 mg/kg/day) was used as positive control and untreated animals as negative control in the study. There were 6 animals in each group. RESULTS: Untreated animals showed P. carinii infection level with a mean +/= standard deviation log number of cysts per gram of lung tissue of 4.6 +/= 1.6 at the end of the experiment. Trimethoprim-sulfamethoxazole 50/250 mg/kg/day has significantly reduced the log number of cysts per gram to 1.8 +/= 1.6 (p<0.001). There was no reduction found in the number of cysts in infected animals treated with 30, 50, and 100 mg of propolis/kg/day, and so the results were not statistically significant (p>0.05) compared with the control group. CONCLUSION: In our rat model of pneumocystosis the efficacy of propolis, this was used in folk medicine since ancient times, found completely ineffective.

Disturbance of pro-oxidative/antioxidative balance in allogeneic peripheral blood stem cell transplantation.

High dose chemotherapy causes increased free radical formation and depletion of tissue antioxidants. Whether allogeneic hematopoietic stem cell transplantation (HSCT) has an effect on oxidative stress is uncertain. The aims of the study were to determine the effect of allogeneic HSCT on plasma concentrations of antioxidants and oxidative stress biomarkers, and to investigate their relationships with graft-versus-host disease (GVHD), conditioning regimens, and transplant-related mortality (TRM) in patients with hematological malignancies. Patients (n=25) undergoing allogeneic HSCT from HLA-matched sibling donors were enrolled in the study. Plasma oxidant and antioxidant status were measured at day -1 before transplantation and 30 days after HSCT. In both myeloablative (n=14) and non-myeloablative (n=11) transplant groups, the mean levels of plasma malondialdehyde (MDA) and nitric oxide (NO) increased after allogeneic HSCT (p <0.01), whereas superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) activities decreased compared with baseline values (p <0.01). No significant relationships were found between either the pretransplant or post-transplant mean levels of the oxidative stress parameters and the existence of graft-versus-host disease (GVHD), the type of conditioning regimen, or transplant related mortality (TRM). This study documents a significant disturbance of pro-oxidative/antioxidative balance in the plasma of patients undergoing allogeneic HSCT regardless of the intensity of the conditioning regimen.

Factors related to complementary/alternative medicine use among cancer patients in central Anatolia.

AIMS AND BACKGROUND: We aimed to evaluate the prevalence of and factors related to the use of complementary/alternative medicine among cancer patients undergoing or following conventional treatment at the Erciyes University Oncology Hospital in Central Anatolia. STUDY DESIGN AND PATIENTS: Face-to-face interview and a questionnaire were carried out with cancer patients attending the outpatient clinic of Medical Oncology. Questionnaire items included patients' demographic data, treatment, use of complementary/alternative medicine and possible related factors. Multivariate analysis was performed to compare the factors related to use of complementary/alternative medicine. RESULTS: A total of 268 consecutive cancer patients were enrolled in the study. Overall, 43% of the patients were using or had used complementary/alternative medicine. Totally, 90% of the patients using complementary/alternative medicine utilized herbs, and most of the herbs used were stinging nettle. Nearly half of the patients using complementary/alternative medicine (46.1%) were aiming to fight the disease. Among users, nearly half of them regarded the method used as effective and 54 (50.5%) suggested the use of complementary/alternative medicine to other patients. Only 23.1% of the patients discussed the use of complementary/alternative medicine with their physician. In logistic regression analysis, younger age, higher educational status, advanced stage of the disease, longer duration of the disease and current treatment status were significantly associated with the use of complementary/alternative medicine. In our regression model, the predictivity rate of these variables was 72.2% for use of complementary/alternative medicine according to the backward Wald test. CONCLUSIONS: Use of complementary/alternative medicine among cancer patients in our center is modestly high, and the most common method is herbal therapy. Communication between the patient and the physician should be improved on this subject.

The effect of zymosan and the protective effect of various antioxidants on fracture healing in rats.

AIM: To investigate the effects of free oxygen radicals and various antioxidants on bone healing after experimental formation of fracture. MATERIALS AND METHODS: Fifty male rats were used and divided into five groups (ten rats in each). The right forelimbs of the rats were broken by bimanual compression method. One hour before this procedure, 5 ml/kg of intraperitoneal (i.p.) physiologic saline were given to the control Group 1. All 40 rats in the experimental Groups 2, 3, 4 and 5 were treated with i.p. zymosan at a dosage of 100 mg/kg to induce the production of free radicals by stimulating NADPH oxidase in polymorphonuclear leukocytes. Zymosan induction was stopped on the fifth post-fracture day. In addition to the zymosan, i.p. 1 g/kg/day of dimethyl sulfoxide were given to the animals in Group 3, 50 mg/kg/d of Ginko biloba Extract (EGb 761) in Group 4 and 500 mg/kg/day of vitamin C in Group 5. Radiographs of the fractures of all animals were obtained to assess callus formation, remodeling and bridging bone formation under ether anesthetics on postfracture day 7, 14 and 21. All rats were euthanized on day 22, and sections of the radius and ulna were examined both histologically with light and electron microscopy and ultrastructurally. Statistical analysis was made with Kruskal-Wallis variance analyze test and comparison between groups was performed by Dunn's multiple comparison test. RESULTS: An impairment of bone healing was observed in Group 2 inducted with purely zymosan. Variable results were obtained for bone healing in the groups treated with various antioxidants. There was very significant difference of fracture healing between Groups 1 and 2 both histologically and radiologically (P < 0.001). There was significant difference between Groups 2 and 5 radiologically (P < 0.05). CONCLUSION: Free oxygen radicals demonstrate a negative effect on fracture healing and vitamin C (an antioxidant) partially prevents the negative effect of zymosan on fracture healing.

Testosterone and zinc supplementation in castrated rats: Effects on plasma leptin levels and relation with LH, FSH and testosterone.

The present study aims to examine how zinc and testosterone supplementation, in combination and separately, affect plasma LH, FSH and leptin levels in castrated rats. Eighty experimental animals used in the study were allocated to 8 groups, each containing an equal number of rats. Group 1, control group; Group 2, castration group; Group 3, testosterone group (5 mg/kg/day); Group 4, zinc-supplemented group (3 mg/kg/day); Group 5, testosterone and zinc-supplemented group; Group 6, zinc-supplemented castration group; Group 7, testosterone and castration group; and Group 8, zinc-supplemented, testosterone and castration group. Plasma zinc, leptin, LH, FSH and free and total testosterone levels were determined in the blood samples collected from the animals by decapitation. Group 2 had the highest leptin levels and together with group 6, it also showed the highest LH and FSH levels (p<0.01). The lowest leptin levels were observed in groups 3 and 7 (p<0.01). Leptin levels in groups 4 and 6 were higher than those in groups 1, 5 and 8 (p<0.01). LH levels in group 4 were lower than those in groups 2 and 6 and higher than those in all other groups (p<0.01). Free and total testosterone levels in groups 7 and 8 were lower than those in groups 3 and 5, but higher than those in all other groups (p<0.01). Plasma LH levels may be more effective than testosterone on plasma leptin and zinc may be an important mediator of the effect LH has on leptin.

The effects of zinc deficiency and testosterone supplementation on leptin levels in castrated rats and their relation with LH, FSH and testosterone.

AIM: The aim of this study was to investigate how zinc-deficiency and testosterone supplementation, both in combination and individually, affect plasma LH, FSH and leptin levels in castrated rats. DESIGN: Group 1, Control Group. Group 2, Castration Group. Group 3, Testosterone Group. Group 4, Zinc-deficient Group. Group 5, Testosterone, Zinc-deficient Group. Group 6, Zinc-deficient, Castration Group. Group 7, Testosterone, Castration Group. Group 8, Zinc-deficient, Testosterone, Castration Group. MEASUREMENTS: Plasma zinc, leptin, LH, FSH, free and total testosterone levels were measured. RESULTS: Group 2 had the highest levels of leptin and LH, besides having the highest FSH levels together with Group 6 (p<0.01). Groups 5 and 8 had the lowest leptin levels (p<0.01). Leptin levels in Groups 4 and 7 were higher than those in Groups 5 and 8, but lower than those in all other groups (p<0.01). LH levels in Group 4 were not different than those in Groups 3, 5 and 8, but significantly lower than those in all other groups (p<0.01). Free and total testosterone levels were higher in Group 4 than in castration groups that were not supplemented testosterone, but were lower in the former than in all others (p<0.01). CONCLUSION: Plasma LH may be more effective than testosterone on plasma leptin and zinc can be an important mediator of the effect LH exercises on leptin.

Effects of zinc deficiency and supplementation on malondialdehyde and glutathione levels in blood and tissues of rats performing swimming exercise.

The aim of the study was to investigate the effects of zinc deficiency and supplementation on lipid peroxidation and glutathione levels in blood and in some tissues of rats performing swimming exercise. Forty adult male Sprague-Dawley rats were divided into four groups: group 1, zinc-deficient consisted of swimming rats; group 2 consisted of zinc-supplemented swimming rats; groups 3 and 4 were the swimming and nonswimming controls, respectively. The levels of malondialdehyde and glutathione were measured after 4 wk of zinc-deficient or zinc-supplemented diet and 30 min of swimming exercise daily. The erythrocyte glutathione levels of groups 2 and 4 were significantly higher than those of groups 1 and 3 (p<0.01). The plasma malondialdehyde level of group 1 was significantly higher than all other groups. The glutathione levels in liver, kidney, striated muscle, and testes of group 2 were higher than in the other groups (p<0.01) and higher in kidney and striated muscle of group 3 than in groups 1 and 4 (p<0.01). The tissue malondialdehyde levels of striated muscle, liver, kidney, and testes of group 1 were significantly higher than for all other groups (p<0.01). Our findings suggest that both swimming exercise and zinc deficiency result in an increase of lipid peroxidation in tissues and that zinc supplementation prevents these alterations by the activation of the antioxidant system.

Zinc prevention of electromagnetically induced damage to rat testicle and kidney tissues.

The aim of this study was to investigate the extent of lipid peroxidation when zinc is administered to rats periodically exposed to a 50-Hz electromagnetic field for 5 min at a time over a period of 6 mo. Twenty-four Sprague-Dawley adult male rats were subdivided in groups of eight animals each. Group 1 served as untreated controls, group 2 was exposed to an electromagnetic field but received no additional treatment, and group 3 was exposed to electromagnetic radiation and treated with 3-mg/kg daily intraperitoneal injections of zinc sulfate. The erythrocyte glutathione activity (GSH) and the plasma, testicle, and kidney tissue levels of zinc (Zn) and of malondialdehyde (MDA) were measured in all of the animals. The plasma and testicle MDA levels in group 2 were higher than those in groups 1 and 3, with group 3 values significantly higher than those in group 1 (p<0.001). The kidney MDA levels in group 2 were higher than in groups 1 and 3 (p<0.001). The erythrocyte GSH level was lower in group 2 than in groups 1 and 3, with group 1 significantly lower than group 3 (p<0.001). In testicle and kidney tissues, the GSH levels in group 1 were lower than for groups 2 and 3, with group 2 significantly lower than group 3 (p<0.001) The plasma zinc levels were highest in group 3, followed by group 1 and group 2, which showed the lowest value (p<0.001). These results indicate that testicle and kidney tissue damage caused by periodic exposure to an electromagnetic field are ameliorated or prevented by zinc supplementation.

The role of free oxygen radicals in noise induced hearing loss: effects of melatonin and methylprednisolone.

The aim of this study was to investigate the role of cochlear damage caused by free oxygen radicals occurring as a result of exposure to noise and to determine the prophylactic effects of melatonin and methylprednisolone. Fifty male albino guinea pigs were randomly divided into five groups. All groups were exposed to 60 h of continuous wide band noise at 100+/-2 dB, except group I. Group I was not exposed to noise or treated with drugs. Group II was exposed to noise and not treated with drugs. Group III was exposed to noise and treated with melatonin. Group IV was exposed to noise and treated with methylprednisolone. Group V was exposed to noise and treated with melatonin and methylprednisolone. A high dose of 40 mg/kg methylprednisolone and/or 20 mg/kg melatonin were administered intramuscularly 24 h before exposure to noise, immediately before noise exposure and once a day until noise exposure was completed. Just after the noise ended, guinea pigs were decapitated. Venous blood was obtained into tubes with EDTA and it was used to measure activity levels of plasma malondialdehyde, erythrocyte glutathione peroxidase and the cochlear tissue malondialdehyde. After the noise ended, in comparison group II with I; it was found that the malondialdehyde activity of the plasma and tissue had increased, the erythrocyte glutathione peroxidase activity levels had decreased and consequently, hearing thresholds had increased (P<0.01). A significant difference was found in the malondialdehyde and erythrocyte glutathione peroxidase activity levels between groups II and III (P<0.01) and the hearing thresholds exhibited a parallel trend (P<0.05). The hearing threshold and malondialdehyde activity levels obtained from groups IV and V were found to be similar to those of group II (P>0.05). As a conclusion, we suggest that the use of methlyprednisolone in order to prevent the cochlear damage caused by noise does not provide sufficient prophylaxy, however the use of melatonin provides a more effective prophylaxy, thus being a promising alternative.