Effects of Stinging Nettle (Urtica Dioica L.,) on Antioxidant Enzyme Activities in Rat Model of Mammary Gland Cancer.

Stinging nettle (Urtica dioica L.,) is a medicinal herb commonly used by humans. The role of reactive oxygen metabolites on cancer etiology is known. There are some studies about the antioxidant effects of Urtica Dioica (UD) on therapy of some cancer types. This study aimed to investigate the effects of UD on antioxidant enzyme activities and mammary gland cancer induced by in rats-N-methyl-N-nitrosourea (NMU) carcinogenesis. Rats were divided into four groups: a untreated group (Group 1), a NMU group (Group 2) given 50 mg/kg NMU by intraperitoneal (i.p.) injection, a NMU group (Group 3) treated with UD, a control group (Group 4) fed with 50g/kg UD. After 5.5 months, rats were decapitated, and mammary tissue and blood samples were obtained. There was a significant (p<0.05, p<0.01, respectively) increase in plasma malondialdehyde (MDA) levels of group 2 compared with group 1 and 4. The superoxide dismutase (SOD) activity of the erythrocytes was decreased in group 3 than the other groups (p<0.0001). The erythrocyte catalase (CAT) activity was significantly increased in group 4 compared with group 2 and 3 (p<0.05, p<0.01, respectively). The number of animals with palpable tumors was 6 (46.15%) in group 2, and 2 (13.3%) in group 3 at the end of the 22nd week. Although group 3 had lower palpable tumor number than group 2, the difference was not statistically significant (p=0.096). The results showed that UD constituents may have effects on lipid peroxidation and some antioxidant enzyme activities, and may slow the formation of mammary tumor.

The effects of low dose N-acetylcysteine (NAC) as an adjunct to cardioplegia in coronary artery bypass surgery.

OBJECTIVE: We aimed to evaluate the efficacy of low dose N-acetylcysteine (NAC) against myocardial ischemia-reperfusion damage in coronary artery bypass surgery accompanied by cardiopulmonary bypass (CPB). METHODS: Thirty patients operated due to triple coronary artery disease were enrolled into this prospective randomized study (control group -n=15 and NAC group - n=15). N-acetylcysteine was added to induction cardioplegia solution in dose of 4 mmol/l and in dose of 2 mmol/l to maintenance cardioplegia solution in the NAC group. Hemodynamic measurements were performed before and after anesthesia with different intervals. Creatine kinase-MB (CK-MB) levels were analyzed during 24 hours postoperatively. Blood samples were obtained from coronary sinus before CPB (T1), just before the cross-clamp removed (T2) and 30 minutes later (T3). Malondialdehyde (MDA), glutathione peroxidase (GSH-Px), nitric oxide (NO) levels and neutrophil percentage were determined. Statistical analysis was performed using student's t test, Chi-square and two-way ANOVA tests. RESULTS: There were no significant differences between the two groups with regard to the hemodynamic parameters, and CK-MB levels. The MDA levels were significantly lower in NAC group than in control group during reperfusion period (0.75 nmol/l vs 0.88 nmol/l, p<0.05). Neutrophil percentage in coronary sinus blood was significantly lower in NAC group than in control group during the reperfusion period (77.6% vs 82.7%, p<0.05). The GSH-Px and NO levels were also not statistically different between groups. CONCLUSION: Low dose NAC as an adjunct to cardioplegic solutions effectively reduces myocardial oxidative stress in coronary bypass surgery with cardiopulmonary bypass, but may not restore the myocardial injury.

Antioxidant effects of methionine, alpha-lipoic acid, N-acetylcysteine and homocysteine on lead-induced oxidative stress to erythrocytes in rats.

Lead, widely used in industry, is a great environmental health problem. Many studies have examined its effects on the health of both humans and animals. Experimental studies have shown that sulphur-containing antioxidants have beneficial effects against the detrimental properties of lead. The present study was designed to investigate markers of oxidative stress (hemoglobin (Hb) in whole blood, malondialdehyde (MDA) in sera; superoxidase dismutase (SOD) and glutathione peroxidise (GSH-Px) in erythrocyte hemolysate and vitamins A and E in plasma) in rats given lead (2000ppm) with or without sulphur-containing antioxidants (l-methionine (Met) (100mg/kg/day), N-acetylcysteine (NAC) (800mg/kg/day), l-homocysteine (Hcy) (25mg/kg/day), lipoic acid (LA) (50mg/kg/day)) in their water for 5 weeks. In the lead group, Hb and plasma vitamin E levels were significantly lower whereas MDA levels were significantly higher compared to controls (p<0.05). Hb levels in lead-methionine and lead-LA groups were significantly higher than the lead group (p<0.01). MDA levels were reduced in all groups compared to the lead group (p<0.01). There was a decrease below control values in erythrocyte SOD (p<0.01) and GSH-Px (p<0.05) levels in the lead-LA group. Plasma vitamin A levels were significantly high in lead-methionine group compared to lead group (p<0.01). In conclusion, the data suggests that oxidative stress induced by lead is reduced by sulphur-containing compounds.

Circulating leptin, zinc, and copper levels after extracorporeal circulation.

OBJECTIVE: The role of leptin in the acute stress response to extracorporeal circulation has been well documented, however, the relationship between leptin and zinc has not been investigated previously. We aimed to research the circulating leptin, zinc, and copper levels before, during, and after the extracorporeal circulation, and effect of preoperative zinc administration to these. METHODS: Twenty patients who were taken to elective coronary artery bypass grafting operations using extracorporeal circulation were taken to this research and divided into two equal groups (n1, n2). In both groups blood samples were taken just before the operation (T0), at the end of operation (T1), and at the first postoperative day (T2). In the second group (n2) oral zinc (50 mg, once a day) was administered to patients for 5 days, preoperatively. The serum leptin, zinc, and copper levels were studied. RESULTS: In group n1 circulating leptin levels were significantly increased at T2 when compared to T0 and T1 (p<0.05); zinc levels were decreased at T2 when compared to T0 and T1 (p<0.05); copper levels were decreased at T2 when compared to T0 (p<0.05), and decreased at T1 when compared to T0 (p<0.05). In group n2 circulating leptin levels were significantly increased at T2 when compared to T0 and T1 (p<0.05); zinc levels were decreased at T2 when compared to T0 and T1 (p<0.05); copper levels were increased at T2 when compared to T1 (p<0.05). CONCLUSIONS: These results indicate that circulating leptin levels increase after the extracorporeal circulation as an acute response, while zinc and copper levels decrease at the same period. Preoperative zinc administration does not prevent the leptin response after extracorporeal circulation.

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.

Levels of cytokines (IL-1beta, IL-2, IL-6, IL-8, TNF-alpha) and trace elements (Zn, Cu) in breast milk from mothers of preterm and term infants.

It has been well documented that human milk contains several immunomodulator components which are important during infant period when the newborn's immune system is still under development. In this study, we aim at examining levels of cytokines, zinc (Zn), and copper (Cu) in milk from mothers of premature and mature infants, and comparing changes during lactation periods consequently. Milk was collected from total of 40 mothers (group M: mothers of mature infants, n = 20; group PM: mothers of premature infants, n = 20) from four lactation stages: colostrum (0-7 days), transitional (7-14 days), mature milk (21 days), and mature milk (2nd month). Levels of cytokines (interleukin [IL]-lbeta, IL-2, IL-6, IL-8, tumor necrosis factor-alpha [TNF-alpha]) were determined by chemiluminesence method, whereas atomic absorption spectrophotometer was used for the determination of Zn and Cu levels. Cytokine levels were determined to be high in colostrum and transient milk from mothers of full-term infants, whereas their levels were reduced drastically in the 21st day and the 2nd month milk (P < .01, P < .001). Similar trends were observed in milk from mothers of premature infants, but cytokine levels were significantly lower in colostrum compared to colostrum from mothers of mature infants (P < .01). The differences in cytokine levels were continuous in transient milk (P < .05) and mature milk (21 days) (P < .05), whereas there was no statistically significant differences between milk from both groups of mothers in the 2nd month (P > .05). Zn levels in milk from mothers of premature infants were significantly lower compared to the ones from mothers of mature infants (P < .01) and these differences continued through the 2nd month. Although Cu levels were lower in milk from mothers of premature infants, there was no statistically significant difference except colostrum (P > .05). Our results clearly demonstrate that the level of immunomodulating agents such as cytokines and trace elements in milk from mothers of premature infants is less than the level of the same agents in milk from mothers of full-term infants. Although there are commercially available products for infant feeding, human milk is still the best natural nutrient for newborns. Therefore, when premature infants are breastfed, necessary precautions such as supplemantary diets must be considered for possible infections and risks related with immune system deficiency.

Effects of trace element levels on platelet aggregation.

Platelet aggregation was measured by an optical method in 32 patients with iron-deficiency anemia at the time of diagnosis and after a period of supplementation with iron. Epinephrine- and adenosine diphosphate-induced platelet aggregation were lower in anemic patients than in the controls (p<0.05). After iron-supplementation therapy, these values showed no significant differences. If induced by collagen or ristocetin, platelet aggregation was the same for patients and controls, but increased after treatment of patients (p<0.05). The plasma zinc values did not show significant differences among the subjects included in this study. These results show that iron is involved in the enzymatic systems that regulate platelet aggregation. The exact nature of this interaction is still to be determined.

Investigation of antioxidant vitamins (A, E and C) and selenium levels in chickens receiving estrogen or testosterone.

In the present study estrogen or testosterone was administered to broiler chickens (6 weeks old) for 5 weeks and levels of antioxidant vitamins (A, E and C) and selenium (Se) were determined. In animals who received estrogen, vitamins A, E, C and Se levels were 0.70 +/- 0.19, 11.0 +/- 2.45, 20.0 +/- 5.17 and 130.0 +/- 25.0 microg l(-1), respectively. Vitamins A, E, C and Se levels in the testosterone-administered group were found to be 0.54 +/- 0.16, 9.9 +/- 1.96, 18.0 +/- 5.18 and 100.0 +/- 18.0 microg l(-1), respectively. Vitamins A, E, C and Se levels were found to be significantly increased in the estrogen-administered group compared to the controls (p < 0.01, p < 0.01, p < 0.05, p < 0.05, respectively). Although all parameters were increased in testosterone-treated animals, only increases in vitamins A and E were found to be statistically significant (p < 0.01, p < 0.01, respectively). Based on the present findings, estrogen and testosterone show direct antioxidant effects by increasing the activities of some enzymes and they also cause an increase in antioxidant vitamin levels and hence indirectly also contribute to antioxidant capacity.