Ibrahim Hanifi Ozercan

Melatonin suppresses cisplatin-induced nephrotoxicity via activation of Nrf-2/HO-1 pathway.

BackgroundCisplatin, one of the most effective and potent anticancer drugs, is used in the treatment of a wide variety of both pediatric and adult malignancies. However, the chemotherapeutic use of cisplatin is limited by its serious side-effects such as nephrotoxicity and ototoxicity. Cisplatin chemotherapy induces a reduction in the antioxidant status, leading to a failure of the antioxidant defense against free-radical damage generated by antitumor drugs. Cisplatin-induced oxidative stress in the kidney was partially prevented by antioxidant treatments using superoxide dismutase, glutathione, selenium and flavonoids. Melatonin and its metabolites possess free-radical scavenging activity and it has been shown that they protect against cisplatin toxicity. However, the mechanism of the protective effects of melatonin against cisplatin-induced nephrotoxicity is still essentially unknown. We therefore designed this study to investigate the underlying mechanism of the protective effect of melatonin against cisplatin-induced renal damage in a rat nephrotoxicity model in vivo.MethodsTwenty eight 8-week-old male Wistar rats were divided into four groups of control, melatonin treatment (4 mg/kg b.w i.p. for 10 days), cisplatin treatment (7 mg/kg b.w., i.p.) and melatonin and cisplatin combination treatment. Serum urea nitrogen (urea-N) and creatinine levels were measured. Histopathological changes were evaluated. In addition, we analyzed the expression levels of HO-1, Nrf2, NF-κB and AP-1 in Western blot analysis.ResultsBoth serum creatinine and urea nitrogen increased significantly following cisplatin administration alone; these values decreased significantly with melatonin co-treatment of cisplatin-treated rats. Histological analysis showed that cisplatin caused damage in the proximal tubular cells in the kidneys of cisplatin-treated rats; these changes were reversed by melatonin co-treatment. Upon Western blot analysis, melatonin treatment increased Nrf2 accumulation in the nuclear fraction, and increased the expression of HO-1 in the cytosolic fraction as compared to the cisplatin-treated rats. Expressions of NF-κB p65 and AP-1 were increased significantly in the kidneys of rats treated with cisplatin compared with the expression in the kidneys from the control, melatonin-only-treated and melatonin co-treated rats.ConclusionOur present data suggest that melatonin attenuates cisplatin-induced nephrotoxicity possibly by modulating Nrf2/HO-1 signaling.

Protective effects of nanostructures of hydrated C60 fullerene on reproductive function in streptozotocin-diabetic male rats

Diabetes mellitus is a well-recognized cause of male sexual dysfunction and impairments of male fertility. Streptozotocin (STZ) is used for medical treatment of neoplastic islet β-cells of pancreas and producing of animal model of diabetes mellitus type 1 that is characterized by suppression of reproductive activity due to the hyperglycaemia-induced oxidative stress and histopathological alterations in testes. Seeking for the agents that could alleviate diabetes-induced damage to reproductive system is yet the important area of inquiry. The present study was designed to evaluate whether hydrated C(60) fullerene (C(60)HyFn), which is known to be powerful bioantioxidant, eliminate testicular dysfunction induced by STZ-diabetes in rats. Wistar strain male albino rats were divided into four groups of six animals each: (1) control group, (2) C(60)HyFn-treated nondiabetic group, (3) STZ-diabetic group and (4) C(60)HyFn-treated diabetic group. Once hyperglycaemia was induced by STZ, rats in the second and fourth groups were treated with C(60)HyFn (in the form of drinking water) at the dose of 4μg/kg daily for 5 weeks. In diabetic rats, relative weights of right cauda epididymis, seminal vesicles, prostate, sperm motility and epididymal sperm concentration were significantly less than those of control group, but which were restored in the fourth group treated with C(60)HyFn (p<0.001). In hematoxylin and eosin staining, marked histopathological changes including degeneration, desquamation, disorganisation and reduction in germinal cells, interstitial oedema and congestion were evident in the testis of diabetic rats, but C(60)HyFn treatment resulted in recovery of histopathological changes and an increase in Johnsens testicular score significantly (p<0.001). C(60)HyFn treatment restores the increased apoptosis induced by STZ-diabetes. In diabetic rats, levels of serum testosterone, testicular reduced glutathione (GSH) and alpha-tocopherol were significantly reduced and testicular lipid peroxidation level was increased (p<0.001). Nevertheless, treatment of diabetic rats with C(60)HyFn resulted in significant corrective effects on these parameters towards the control levels. C(60)HyFn, applied alone, did not exert any toxic effects in testicular tissues. Furthermore, C(60)HyFn treatment in diabetic and nondiabetic rats resulted in considerable elevations of some important polyunsaturated fatty acids. In conclusion, we have presented for the first time substantial evidence that administration of C(60)HyFn significantly reduces diabetes-induced oxidative stress and associated complications such as testicular dysfunction and spermatogenic disruption.

A comparison of leptin and ghrelin levels in plasma and saliva of young healthy subjects

In the last 10 years, saliva has been increasingly used as a diagnostic fluid and in predictions of disease progression. Leptin and ghrelin are synthesized in several tissues including the salivary glands. The action of ghrelin is antagonistic to that of leptin. This study was undertaken to measure and compare the saliva ghrelin-leptin and plasma ghrelin-leptin levels in healthy young subjects. In 30 healthy subjects, after an overnight fast, saliva and plasma leptin levels were measured using the ELISA method while saliva and plasma immunoreactive ghrelin levels were measured using a commercial radioimmunoassay (RIA). The latter uses 125I-labeled bioactive ghrelin as a tracer and a rabbit polyclonal antibody raised against full-length octanoylated human ghrelin (Phoenix, Europe, Karlsruhe, Germany). The results of this investigation revealed that saliva leptin levels (6.19+/-2.10 microg/l) were lower than plasma levels (7.39+/-3.23 microg/l) while saliva ghrelin levels (188.5+/-84.7 pg/ml) were higher than plasma levels (126.4+/-38.5 pg/ml), when male and female subjects were considered together. Saliva leptin levels (5.93+/-1.94 microg/l) were lower than plasma levels (6.22+/-2.92 pg/ml) while saliva ghrelin levels (190.3+/-80.2 pg/ml) were higher than plasma levels (120.4+/-35.7 pg/ml) in young males. Saliva leptin levels (6.47+/-2.29 microg/l) were lower than plasma levels (8.73+/-3.14 microg/l) while saliva ghrelin levels (183.2+/-90.2 pg/ml) were higher than plasma levels (129.3+/-42.8 pg/ml) in young females, and both saliva and plasma leptin levels were slightly lower in male subjects in comparison with female subjects. Also, Immunohistochemistry study indicated that ghrelin positivity was found in ductus epithelium of salivary gland. We have demonstrated for the first time that saliva ghrelin levels were higher than in plasma while saliva leptin levels were almost the same as in plasma. Measurements of ghrelin and leptin in saliva is non-invasive, simple, and generally much preferred by patients and thus may be an acceptable alternative to plasma sampling.

A comprehensive immunohistochemical examination of the distribution of the fat-burning protein irisin in biological tissues.

Irisin was first identified in skeletal muscle cells, but its precise location has not yet been demonstrated, and there is limited information about irisin protein in other human and rat tissues. The present immunohistochemical study was undertaken to screen skeletal muscle and other tissues for irisin immunoreactivity. İrisin staining was found in the brain (neurons and neuroglia), cardiac and skeletal muscle (fibers) and skin (sebaceous glands) tissues in male rats. In both human adult and fetal skeletal muscle, the most intense immunohistochemical staining was in the perimysium and endomysium, in the peripheral nerve (epineurium) and axon and nerve sheaths spreading among the cells, in the sarcoplasma and subendomysium. Irisin was also demonstrated in the testis (seminiferous tubules, some spermatogenic cells in fetal and Leydig cells in fetal and adult testis, ductus epididymis in fetal human epididymis); pancreas (islets of Langerhans, serous acini cells, intralobular and intralobular ducts cells); liver (hepatocytes; Kupffer cells and sinusoidal endothelial cells); spleen (subcapsular region and periarterial lymphatic sheets); the stomach (gastric parietal cells, tunica muscularis cells). We conclude that the fat-burning protein irisin locally produced in peripheral and central tissues could act as a gatekeeper of metabolic energy regulation in those tissues, since this myokine converts white into brown adipose tissue, enhancing energy expenditure.

Does aprotinin reduce lung reperfusion damage after cardiopulmonary bypass

OBJECTIVE The role of aprotinin in the prevention of lung reperfusion injury was investigated in the patients undergoing cardio-pulmonary bypass (CPB) for coronary artery bypass grafting (CABG) operations. METHODS The study was planned randomly and prospectively. Two hundred milliliters of physiological saline solution was added to the prime solution of patients in group I (n=10) whereas, 200 ml aprotinin (Trasylol, Bayer AG) was given to patients in group II (n=10). In order to measure lung tissue malondialdehyde (MDA) levels, glutathion peroxidase (GSH-Px) activity levels and polymorphonuclear leukocytes (PMNs) numbers, lung tissue samples were taken before CPB and 5 min after removing the cross clamp. In addition, alveolo-arterial oxygen difference (AaDO(2)) for tissue oxygenation was calculated by obtaining arterial blood gas samples. RESULTS MDA levels before CPB increased from 41.72+/-21.00 nmol/g tissue to 66.71+/-13.44 nmol/g tissue in group I and from 43.44+/-5.16 nmol MDA/g tissue to 53.22+/-10.95 nmol MDA/g tissue in group II after cross clamp removal (P=0.001 and P=0.021, respectively). The increase in group II was found to be significantly lower than group I (P=0.048). With the initiation of reperfusion, GSH-Px activity decreased in group I from 3.05+/-0.97 to 2.31+/-0.46 U/mg protein (P=0.015) whereas GSH-Px activity in group II decreased from 3.18+/-1.01 to 2.74+/-0.81 U/mg protein (P=0. 055). This decrease in the group II was less than group I (P=0.049). AaDO(2) significantly increased in the group I and II (P=0.012 and P=0.020, respectively), but elevation in the group I was significant than in the Group II (P=0.049). In histopathological examination, it was observed that neutrophil counts in the lung parenchyma rose significantly following removal of cross clamp in both groups (P=0. 001). The increase in group I was significantly larger than in group II (P=0.050). CONCLUSION Results represented in our study indicate that addition of aprotinin (2 million units) into the prime solution during CPB can reduce lung reperfusion injury.

Protective Role of Genistein in Acute Liver Damage Induced by Carbon Tetrachloride

Aim. In the present study, we investigated the protective effect of genistein in experimental acute liver damage induced by CCl4. Method. Forty rats were equally allocated to 5 groups. The first group was designated as the control group (group 1). The second group was injected with intraperitoneal CCl4 for 3 days (group 2). The third group was injected with subcutaneous 1 mg/kg genistein for 4 days starting one day before CCl4 injection. The fourth group was injected with intraperitoneal CCl4 for 7 days. The fifth group was injected with subcutaneous 1 mg/kg genistein for 8 days starting one day before CCl4 injection. Plasma and liver tissue malondialdehyde (MDA) and liver glutathione levels, as well as AST and ALT levels were studied. A histopathological examination was conducted. Results. Liver tissue MDA levels were found significantly lower in group 3, in comparison to group 2 (P < .05). Liver tissue MDA level in group 5 was significantly lower than that in group 4 (P < .001). Liver tissue glutathione levels were higher in group 5 and 3, relative to groups 4 and 2, respectively (P > .05 for each). Inflammation and focal necrosis decreased in group 3, in comparison to group 2 (P < .001 for each). Inflammation and focal necrosis in group 5 was lower than that in group 4 (P < .001). Actin expression decreased significantly in group 5, relative to group 4 (P < .05). Conclusion. Genistein has anti-inflammatory and antinecrotic effects on experimental liver damage caused by CCl4. Genistein reduces liver damage by preventing lipid peroxidation and strengthening antioxidant systems.

Role of L‐carnitine in the prevention of acute liver damage induced by carbon tetrachloride in rats

Background and Aim:  Lipid peroxidation is the most important mechanism in the pathogenesis of acute liver damage with carbon tetrachloride (CCl4). L‐carnitine may prevent lipid peroxidation and thus may protect against liver damage. In the present study we investigated the protective effect of L‐carnitine in experimental acute liver damage induced by CCl4.

Inhibitory Effects of Combination of Lycopene and Genistein on 7,12- Dimethyl Benz(a)anthracene-Induced Breast Cancer in Rats

Breast cancer is one of the most common cancers in women. Carotenoids and soy isoflavones have been postulated to have breast cancer preventive effects. We investigated the potential preventive effects of lycopene and genistein, alone and in combination, on breast cancer development in female Wistar rats treated with 7,12-dimethylbenz[a]anthracene (DMBA), a carcinogen known to induce breast tumors. Mammary carcinogenesis was initiated by a single, oral gavage of DMBA (80 mg/kg body weight) at 55 days of animal age. Fifty female Wistar rats were divided into 5 experimental groups having 10 animals per group: Group 1 (normal control), Group 2 (DMBA control), Group 3 (DMBA + lycopene), Group 4 (DMBA + genistein), and Group 5 (DMBA + lycopene and genistein). Rats were fed either lycopene (20 mg /kg bw) or genistein (2 mg /kg bw) by oral gavage (3 times per week) starting 2 wk prior to DMBA injection. Treatment was continued for 20 wk. Rats treated with DMBA developed mammary tumors with 100% tumor incidence during the 20-wk study. Inhibition of mammary cancer incidence by lycopene (70%), genistein (60%) and their combination (40%) was observed. Tumor weight decreased by 48%, 61%, and 67%, and mean tumor volume decreased by 18%, 35%, and 65% with lycopene, genistein, and lycopene + genistein, respectively (P < 0.01 for the combination). The proportions of adenocarcinoma masses decreased with lycopene and genistein combination (P < 0.05). Administration of lycopene and genistein combination suppressed breast cancer development and was associated with a decrease in MDA, 8-isoprostane, and 8-OhdG levels and with an increase in serum lycopene and genistein levels. Animals administered DMBA developed breast cancer, which was associated with increased expression of Bcl-2 and decreased expression of Bax, caspase 3, and caspase 9 in mammary tissues. Administration of genistein and lycopene in combination was more effective in inhibiting DMBA-induced breast tumors and modulating the expression of apoptosis associated proteins than the administration of each agent alone. Our results suggest that lycopene and genistein are potent antioxidants and, when given in combination, offer maximum protection against DMBA-induced mammary carcinogenesis.

Epigallocatechin gallate attenuates experimental non-alcoholic steatohepatitis induced by high fat diet.

Background and Aim:  In the present study, we examined the preventive role of epigallocatechin gallate (EGCG) in an experimental non‐alcoholic steatohepatitis model induced by a high fat diet.

A Tomato Lycopene Complex Protects the Kidney From Cisplatin-Induced Injury via Affecting Oxidative Stress as Well as Bax, Bcl-2, and HSPs Expression

Cisplatin-induced nephrotoxicity is related to an increase in oxidative stress in the kidney. Lycopene, a carotenoid found in tomatoes, is a potent dietary antioxidant. In the present study, we investigated the effect of the tomato lycopene complex against cisplatin-induced lipid peroxidation and nephrotoxicity in rats. Male Wistar rats (n = 28, 8 wk old, between 200–215 g) were divided into 4 groups: (a) control, (b) tomato lycopene complex (6 mg/kg, daily; consisting of 6% lycopene, 1.5% tocopherols, 1% phytoene and phytofluene, and 0.2% β-carotene), (c) cisplatin (7 mg/kg i.p., single dose), and (d) cisplatin + tomato lycopene complex. Cisplatin administration increased serum urea-N (171 vs. 37 mg/dl) and creatinine (1.80 vs. 0.42 mg/dl) and decreased body weight in comparison with the control rats (P < 0.001). Serum creatinine and urea-N levels were lower in rats treated with tomato lycopene complex + cisplatin compared with rats treated with cisplatin alone (P < 0.001). The renal tissue from the cisplatin-treated rats had greater malondialdehyde (MDA; 172 vs. 93 nmol/g) and 8-isoprostane levels (1810 vs. 610 pg/g) than that from the control rats (P < 0.001). Tomato lycopene complex prevented the rise of MDA and 8-isoprostane (P < 0.001). No measurable lycopene could be detected in the serum of the control and cisplatin-treated rats, whereas lycopene was observed in the serum of rats supplemented with tomato lycopene complex. Renal Bax protein expression was significantly higher in the cisplatin-treated rats than in the control rats, and tomato lycopene complex treatment significantly reduced Bax expression (P < 0.001). The expression of Bcl-2 was higher in tomato lycopene complex/cisplatin-treated rats than in the cisplatin-injected rats (P < 0.05). The expression of renal HSP60 and HSP70 was significantly lower in tomato lycopene complex + cisplatin-treated rats than in rats treated with cisplatin alone (P < 0.001). These results suggest that tomato lycopene complex has protective effects against cisplatin-induced nephrotoxicity and lipid peroxidation in rats.