Konca Altinkaynak

Melatonin reduces lipid peroxidation and nitric oxide during irradiation-induced oxidative injury in the rat liver.

Abstract:  Radiation therapy is a popular and useful tool in the treatment of cancer. Melatonin participates in the regulation of a number of important physiological and pathological processes. Melatonin, a powerful endogenous antioxidant, plays a role in the reduction of oxidative damage. Thirty adult rats were divided into five equal groups. On the day of the experiment, groups I and II were injected with 5 or 10 mg/kg melatonin, respectively, while group III received isotonic NaCl solution. Thirty minutes later, groups I, II and III were exposed to 6.0 Gy whole body ionizing radiation in a single fraction. Group IV was injected with 5 mg/kg melatonin but was not irradiated. The final group was reserved as sham treated. Liver malondialdehyde (MDA) and nitric oxide (NOċ) levels were measured in all groups. Whole body irradiation caused a significant increase in liver MDA and NOċ levels. Hepatic MDA and NOċ levels in irradiated rats that were pretreated with melatonin (5 or 10 mg/kg) were significantly decreased. Malondialdehyde and NOċ levels were reduced in a dose‐related manner by melatonin. The data show that melatonin reduces liver damage inflicted by irradiation when given prior to the exposure to ionizing radiation. The radioprotective effect of melatonin is likely achieved by its ability to function as a scavenger for free radicals generated by ionizing radiation.

Antioxidant Potential and Transferrin, Ceruloplasmin, and Lipid Peroxidation Levels in Women with Preeclampsia

Background The aim of this study was to evaluate lipid peroxidation and antioxidant function in patients with preeclampsia and in normotensive pregnant women and to assess an association with the severity of the disease. Methods Twenty-one patients with mild preeclampsia, 15 patients with severe preeclampsia, and 19 normotensive pregnant women were included in the study. Plasma antioxidant potential (AOP) status, ceruloplasmin (Cp) and transferrin (Trf) levels as antioxidants, and malondialdehyde (MDA) levels as an indicator of lipid peroxidation were measured. Results Whereas the AOP and Trf levels of the severe and mild preeclampsia groups were found to be reduced, the MDA and Cp levels were increased compared with those of the normotensive pregnant group. There were statistically significant negative correlations between AOP and MDA in all groups. No differences were observed between the groups with severe and mild preeclampsia with respect to these analytes. Conclusion Our findings suggest that lipid peroxidation may be an important factor in the pathogenesis of preeclampsia and that plasma antioxidants and oxidants are altered in preeclampsia. However, these findings may not be useful in distinguishing women with severe and mild preeclampsia.

Serum IGF-I and IGFBP-3 in healthy pregnancies and patients with preeclampsia

DESIGN AND METHODS We studied serum levels of IGF-I and IGFBP-3 in 68 pregnant women; 28 mild preeclampsia, 13 severe preeclampsia, and 27 healthy pregnant control subjects. RESULTS When compared with the healthy pregnant group preeclampsia groups had markedly decreased mean serum IGF-I levels. The difference was also significant between the mild and severe preeclampsia groups. Serum mean IGFBP-3 level was also lower in both preeclampsia groups than in healthy pregnancy group, but the difference between the preeclampsia groups did not reach significance. For IGF-I/IGFBP-3 ratio, the mean levels were significantly lower in mild and severe preeclampsia groups than in healthy pregnancy group. Also the mean IGF-I/IGFBP-3 ratio was significantly lower in the severe preeclampsia group compared with the mild preeclampsia group. CONCLUSIONS IGF-1 and IGFBP-3 levels in patients with preeclampsia were compared with healthy pregnant control subjects. IGF-I and IGF-I/IGFBP-3 ratio may be useful for estimate the severity of preeclampsia.

Vitamin E but not Hippophea rhamnoides L. prevented nicotine-induced oxidative stress in rat brain.

Oxidant effects of nicotine in the central nervous system is not clear. The aim of this study was to investigate whether nicotine induces oxidative stress in rat brain, and if it does, to test the effects of Hippophea rhamnoides L. extract (HRe-1) and also vitamin E as a positive control. The groups were: nicotine [0.5 mg/kg/day, intraperitoneal (i.p.)]; nicotine-vitamin E [75 mg/kg/day, intragastric (i.g.)]; nicotine-HRe-1 (250 mg/kg/day, i.g.); and control group (receiving only vehicles). There were eight rats per group and supplementation period was 3 weeks. Malondialdehyde (MDA) level was increased by nicotine in brain tissue, which was prevented by vitamin E whereas not affected by HRe-1. Brain tissue glutathione S-transferase activities of nicotine administered and HRe-1 supplemented groups were lower than control and vitamin E supplemented groups, while glutathione peroxidase (GSH-Px) activities of vitamin E and HRe-1 supplemented groups were lower than the nicotine administered group. Superoxide dismutase activity was not affected by any of the treatments. Total glutathione level was higher in the vitamin E supplemented group compared with control and nicotine administered groups. Vitamin E might have easily diffused to rat brain as a lipid soluble antioxidant, however, the plant extract, HRe-1, would not have sufficiently diffused to the brain to exert its antioxidant effect.

Influence of Smoking on Serum and Milk of Mothers, and Their Infants’ Serum Insulin-Like Growth Factor-I and Insulin-Like Growth Factor Binding Protein-3 Levels

Objective: To investigate the serum and milk in active-smoking and nonsmoking mothers, and their infants’ insulin-like growth factor-I (IGF-I) and insulin-like growth factor binding protein-3 (IGFBP-3) levels. Design and Setting: A cohort study conducted at a tertiary medical center. Subjects: Forty-four mothers (age range: 21–34 years) and their newborns (7 days old) were enrolled in the study. Mothers were interviewed and classified according to their smoking status into one of two groups: the active-smoking mothers (n = 21) and the nonsmoking mothers (n = 23). Results: There was no difference noted in either IGF-I, IGFBP-3 or IGF-I/IGFBP-3 ratios in serum and milk of mothers, and their infants’ serum samples according to maternal smoking. Conclusion: This study demonstrated that maternal smoking (5–10 cigarettes/day) did not influence the maternal and infant serum levels of IGF-I and IGFBP-3 as well as the breast milk levels of these peptides.

Levels of soluble intercellular adhesion molecule-1 in serum of patients with ankylosing spondylitis

AbstractAnkylosing spondylitis (AS) is a chronic, progressive, inflammatory disorder mainly affecting axial skeleton and peripheral joints In this study, soluble intercellular adhesion molecule-1 (sICAM-1), C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) in serum of patients with AS were investigated and compared with those of age- and sex-matched healthy controls. Twenty-one patients with AS not currently under disease-modifying antirheumatic drug (DMARD) treatment (e.g.sulfasalazine or methotrexate) and 20 age- and sex-matched healthy controls were included in the study. Serum sICAM-1, CRP, ESR levels were evaluated using appropriate methods. When compared with the levels in the control subjects, serum CRP and ESR in the patients with AS were significantly elevated. Although serum sICAM-1 levels were increased in AS patients compared with controls, the difference did not reach significance level. Significant positive correlations were observed between sICAM-1 and ESR (r= 0.60, p < 0.0...