Ali Akbas

Nigella sativa protects against ischaemia/reperfusion injury in rat kidneys

BACKGROUND Renal ischaemia followed by reperfusion leads to acute renal failure in both native kidneys and renal allografts, which is a complex pathophysiologic process involving hypoxia and free radical (FR) damage. The oil of Nigella sativa (NSO) has been subjected to considerable pharmacological investigations that have revealed its antioxidant activity in different conditions. But there is no previously reported study about its effect on ischaemia/reperfusion (I/R) injury of kidneys. The aim of this study was to investigate the possible effects of NSO in I/R-induced renal injury in rats. METHODS Thirty healthy male Wistar albino rats were randomly assigned to one of the following groups: control, sham, I/R, NSO+I/R, I/R+NSO and NSO. I/R, NSO+I/R and I/R+NSO rats were subjected to bilateral renal ischaemia followed by reperfusion and then all the rats were killed and kidney function tests, serum and tissue oxidants and antioxidants were determined and histopathological examinations were performed. RESULTS Pre- and post-treatment with NSO produced reduction in serum levels of blood urea nitrogen (BUN) and creatinine caused by I/R and significantly improved serum enzymatic activities of superoxide dismutase (SOD) and glutathion peroxidase (GSH-Px) and also tissue enzymatic activities of catalase (CAT), SOD and GSH-Px. NSO treatment resulted in lower total oxidant status (TOS) and higher total antioxidant capacity (TAC) levels and also significant reduction in serum and tissue malondialdehyde (MDA), nitric oxide (NO) and protein carbonyl content (PCC) that were increased by renal I/R injury. The kidneys of untreated ischaemic rats had a higher histopathological score, while treatment with NSO nearly preserved the normal morphology of the kidney. CONCLUSIONS In view of previous observations and our data, with the potent FR scavenger and antioxidant properties, NSO seems to be a highly promising agent for protecting tissues from oxidative damage and preventing organ damage due to renal I/R.

Antioxidant Status and Oxidative Stress in Primary Open Angle Glaucoma and Pseudoexfoliative Glaucoma

Purpose: The aim of this study was to establish the antioxidant status and oxidative stress in patients with primary open-angle glaucoma (POAG) and pseudoexfoliative glaucoma (PEG). Methods: Serum levels of total antioxidant capacity (TAC) and superoxide dismutase (SOD) as indicators of antioxidant status; and total oxidant status (TOS), nitric oxide (NO), protein carbonyl (PC), and malondialdehyde (MDA) as indicators of oxidative stress were measured from the blood samples of patients with POAG (n = 23), PEG (n = 24) and healthy control subjects (n = 19) by spectrophotometry. Results: Mean TAC level was 0.6 ± 0.1 mmol/L in the POAG group; 0.5 ± 0.1 mmol/L in the PEG group and 1.2 ± 0.3 mmol/L in the control group (p = 0.001). Mean SOD level was 13 ± 0.5 mg/L in the POAG group, 11.6 ± 0.2 mg/L in the PEG group and 9.4 ± 0.6 mg/L in the control group (p = 0.001). Mean TOS level was 19.6 ± 2.6 μmol/L in the POAG group, 21.2 ± 4.2 μmol/L in the PEG group and 15.1 ± 7 μmol/L in the control group (p = 0.001). Mean NO level was 74.3 ± 14.4 µmol/L in the POAG group, 66.1 ± 8.1 µmol/L in the PEG group and 62.3 ± 13.5 µmol/L in the control group (p = 0.005). Mean PC level was 641.5 ± 102.5 nmol/mg in the POAG group, 988.3 ± 214.7 nmol/mg in the PEG group and 654.4 ± 150.7 nmol/mg in the control group (p = 0.001). Mean MDA level was 1.9 ± 0.2 µmol/L in the POAG group, 1.7 ± 0.4 µmol/L in the PEG group and 1.1 ± 0.2 µmol/L in the control group (p = 0.001). Conclusion: The findings of the present study are potentially of significance and add to the growing body of evidence for oxidative stress in POAG and PEG. Decreased antioxidant defense and increased oxidative stress system may play an important role in the pathogenesis of POAG and PEG.

The effects of carvedilol on ischemia-reperfusion injury in the rat testis

OBJECTIVE To analyze the oxidative damage and histopathological alterations caused by ischemia-reperfusion (I/R) injury and ameliorative effects of carvedilol (CVD) in the rat testis. MATERIALS AND METHODS Twenty-one male rats were randomized into 3 groups as follows: Group I (n = 7); control (sham) group, Group II (n = 7); I/R group, in which I/R injury was performed by torsing the left testis 720 ° clockwise for 2 hours and detorsing for 2 hours. Group III (n = 7); CVD treatment group; in addition to I/R process, one-dose of CVD was administered (2mg/kg, i.p) 30 min. before detorsion. Levels of antioxidant enzymes, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) and levels of malondialdehyde (MDA) and protein carbonyl (PC) were determined in testicular tissues and serum of rats. Testicular tissues were also examined histopathologically and Johnsen scores were determined. RESULTS Activities of SOD and GSH-Px in serum and testicular tissues were increased by I/R, but administration of CVD decreased these levels (p < 0.001 and p = 0.001). Significantly increased MDA levels in serum and testicular tissues were decreased by CVD treatment (p < 0.001 and p = 0.001). Concerning PC levels in serum and testicular tissues, there was no statistically significant difference between the groups (p = 0.989 and p = 0.428). There was not a statistically significant difference in terms of mean Johnsen scores between the groups (p = 0.161). CONCLUSIONS Administration of CVD decreased oxidative damage biochemically in the rat testis caused by I/R injury, but histopathologically no change was observed betwe¬en all of the groups.

The biochemical effects of ischemia-reperfusion injury in the ipsilateral and contralateral testes of rats and the protective role of melatonin.

Testicular torsion (TT) is a serious urologic emergency that is observed in adolescent males and that can lead to infertility if left untreated. The ischemia-reperfusion (I/R) injury due to TT has been implicated in the pathogenesis of testicular damage. We investigated the effects of melatonin on oxidative damage in the ipsilateral and contralateral testes of rats induced by unilateral TT. A total of 21 prepubertal male Wistar albino rats were divided into three groups, each consisting of seven rats. In Group 1 (SHAM group): a sham operation to the left testis and bilateral orchiectomy were performed. In Group 2 (I/R group): I/R injury was created by rotating the left testis 720° in a clockwise direction for 2 h and detorsing the testis after 2 h. Group 3 (I/R + MEL group): rats were subjected to I/R injury and one-shot melatonin injection (50 mg kg−1, intraperitoneal (i.p.)). The testes of the rats were excised bilaterally in all groups. The testicular tissue activities of antioxidant catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase enzymes (GSH-Px), and the tissue levels of malondialdehyde (MDA), protein carbonyl (PC) and nitric oxide (NO) were determined. Administration of melatonin caused a significant decrease in lipid peroxidation and enzyme activities in the ipsilateral testis when compared with the control group (P < 0.05). All of the changes in the enzyme activities of the contralateral testis were insignificant (P > 0.05). MDA levels were significantly altered in the contralateral testis (P = 0.009). Melatonin administration decreased the deleterious effects of I/R injury in the ipsilateral torted testes of the rats. The contralateral testes were slightly affected by unilateral TT.

Gradual detorsion of torsioned rat testis attenuates ischemia reperfusion injury

AIM This study was designed to investigate effect of gradual detorsion on testicular ischemia reperfusion injury. MATERIALS AND METHODS A total of 21 male rats were divided into 3 groups, each containing 7 rats. Torsion was created by rotating the left testis 720 degrees in a clockwise direction. Group 1 underwent sham operation. Group 2 (sudden detorsion) served as a torsion/detorsion group, receiving 2 hours torsion and 2 hours detorsion. In group 3, 360 degrees detorsion was done for 20 minutes after 720 degrees torsion for 2 hours. Then, testis was done full detorsion for 100 minutes. At the end of the experiments (fourth hour), left orchiectomy was performed to measure the tissue levels of malondialdehyde (MDA), superoxide dismutase, and glutathione peroxidase and to perform histologic examination in testes. RESULTS The MDA levels of testis tissues were significantly increased in the sudden detorsion group as compared with the sham group. We found decrease of the MDA level in gradual detorsion group, but it was not a statistically significant amount. Significant decrease was found in the superoxide dismutase and glutathione peroxidase activities in the sudden detorsion group as compared with the sham and gradual detorsion groups. Histologic examinations were in accordance with the testicular tissue MDA levels. CONCLUSION In the light of our biochemical and histopathologic findings, we can say that gradual detorsion has a trend to decrease the degree of testicular reperfusion injury in the rat torsion/detorsion model.

Oxidative stress status in patients with acute urticaria

Abstract Background: The conflicting information related to oxidative stress status in patients with chronic idiopathic urticaria has been reported in several studies. However, the association between acute urticaria (AU) and oxidative stress has not been investigated exhaustively. Objectives: To evaluate the role of the oxidative stress in the patients with AU by determining the oxidant/antioxidant activity in AU and to establish its clinical significance. Methods: About 50 patients with AU, (10 males, 40 females) and 30 unrelated healthy controls (4 males, 26 females) were enrolled into the study. The activity of the antioxidant enzymes copper-zinc superoxide dismutase (Cu-Zn-SOD), glutathione peroxidase (GSH-Px) and catalase, and the levels of malondialdehyde (MDA), serum NO and protein carbonyls levels in the plasma were measured spectrophotometrically at samples. Results: A statistically significant increase was observed in serum Cu-ZnSOD activities of the patients when compared with that of the controls (p < 0.001), while a statistically significant decrease was observed in GSH-Px activities of the patients according to the controls (p = 0.002). Serum MDA and NO levels were significantly higher in patients with AU when compared with control group (p < 0.001 for both of them). The levels of protein carbonyls were significantly lower in patients with AU when compared with control group (p < 0.001). Conclusion: It seems there is an oxidative burden in the patients with AU. Cutaneous oxidative stress may play a role in pathogenesis of the disease.

Oxidative stress status in patients with melasma

Abstract Background: Melasma is an acquired skin disease characterized clinically by development of gray–brown macules or patches. The lesions have geographic borders and most often seen on face and less frequently on the neck and forearms. Pathogenesis has not been completely understood yet. Although the disease constitutes a very disturbing cosmetic problem, it has not obtained an efficient treatment. There were not any studies in the literature that evaluates the role of oxidative stress in melasma. Objectives: The evaluation of the role of oxidative stress in melasma. Methods: Fifty melasma patients and 50 healthy volunteers were included in the study. The diagnosis was made clinically and the patients were evaluated by Melasma Area Severity Index. Superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) enzyme activities and malondialdehyde, nitric oxide, protein carbonyl levels were measured both in the melasma group and the control group. Results: SOD and GSH-Px enzyme activities were significantly higher in the patient group in comparison with the control group (p < 0.001). Protein carbonyl levels were significantly lower in the patient group (p < 0.001). Conclusion: The results show that the balance between oxidant and anti-oxidants was disrupted and the oxidative stress increased in melasma. These results improve the understanding of etiology–pathogenesis of the disease and its treatment.

The reference intervals of thyroid stimulating hormone in healthy individuals with normal levels of serum free thyroxine and without sonographic pathologies

Abstract Introduction: The aim of the present study was to investigate the reference intervals for thyroid stimulating hormone (TSH) in healthy individuals with normal levels of serum free thyroxine (fT4) and without sonographic pathologies, and determine the effects of age, gender, and residence on the TSH reference intervals. Subjects and methods: This research was a population-based study conducted in 70 regions. The random sampling method was used to select the 1095 subjects of the study among inhabitants aged 18 and above. Patients who had a previous history of thyroid disease and had been taking medication were excluded from the study as this may have affected their fT4 or TSH levels. In addition, subjects who had serum fT4 without a reference range and abnormal ultrasonography findings were also excluded. A total of 408 subjects were used for establishing the reference intervals for TSH. Results: The data for TSH in the study group were not normally distributed according to the Kolmogorov–Smirnov index. The geometric mean was 1.62 mIU/L, the median was 1.40 mIU/L, and the 95% reference intervals were 0.38–4.22 mIU/L. The median TSH level was higher in females compared to males (p < 0.05). In the female subjects 2.5th percentile of TSH was lower and 97.5th percentile was higher than those of males. The reference intervals of TSH were of lower values in subjects over 50 years old (p < 0.001). Discussion: Studies suggest that determination of the TSH reference intervals may differ due to environmental influences or due to age, gender, and race. It is suggested that the lower limit of normal TSH for the adult Turkish population would be 0.38 mIU/L and the upper limit similar to the traditional value of 4.2 mIU/L. If each clinician uses their population-specific reference interval for TSH, thyroid function abnormalities can be accurately estimated.

Thyroid dysfunctions and sonographic characteristics in northern Turkey: a population-based study.

BACKGROUND AND OBJECTIVES In this study, it was aimed to investigate thyroid functions, sonographic characteristics of thyroid gland, relation of thyroid functions, and cardiovascular risk factors in adult population living in northern Turkey. DESIGN AND SETTINGS The study was conducted in 70 areas (12 urban and 58 rural) in the province of Tokat in northern Turkey from 2005 to 2006. PATIENTS AND METHODS The study included about 530 000 inhabitants of 18 years and older. Demographic characteristics and thyroid sonographic findings were noted for each subject, and blood samples were collected for measuring serum lipids and thyroid function tests. RESULTS A total of 1095 subjects (541 males, 554 females) were included, and their mean age (SD) was 41.4 (17) years. Mean thyrotropin (TSH) and free T4 levels (SD) were 1.5 (1.6) μIU/mL and 1.2 (0.1) ng/dL, respectively, in males, and 2.2 (6.6) μIU/mL and 1.2 (0.3) ng/dL, respectively, in females (P<.05). According to mean TSH levels, the prevalence of overt hypothyroidism, overt hyperthyroidism, subclinical hypothyroidism, and subclinical hyperthyroidism was detected as 1.6%, 0.5%, 2.7%, and 4.9%, respectively. Nodular goiter, multinodular goiter, and thyroid heterogeneity were determined as 13.8, 32.1, and 15.6%, respectively. The correlation between cardiovascular risk factors and serum TSH levels was not statistically significant (P>.05). The age was independently and significantly associated with serum TSH levels (P<.0001). CONCLUSION In terms of high prevalence of thyroid dysfunction and nodular goiter, thyroid diseases must be concluded as a public health problem, and accurate and effective strategies must be identified.

Caffeic acid phenethyl ester as a remedial agent for reproductive functions and oxidative stress-based pathologies of gonads.

In recent years, the studies on the roles of caffeic acid phenethyl ester (CAPE) in several disease models and cell cultures are tremendously growing. It is such a great molecule that was used by ancient times to ameliorate some diseases and nowadays, it is used by modern medicine to test the effectiveness. In this mini-review article, the protection capability of CAPE, as a liposoluble antioxidant and a potent nuclear factor kappa B inhibitor, on oxidative and non-oxidative ovary, and testis damages has been summarized. In view of our laboratory findings/experience and those reported in the hitherto literature, we suggest that CAPE possesses protective effects for pathologies of the reproductive organs induced by untoward effects of harmful molecules such as free oxygen radicals, pesticides, methotrexate, and MK-801 (dizocilpine).