Assessment of leptin-to-adiponectin ratio in prediction of insulin resistance and nutrition status in a geriatric female population.

Both obesity and malnutrition leading to cachexia and sarcopenia are relevant risk factors in the development of many diseases. They also increase mortality, also prolong hospitalisations and convalescence, and undoubtedly increase the cost of treatment, mostly in the elderly populations. The aim of the study was to assess the relationship between the levels of leptin and adiponectin with regard to insulin resistance and malnutrition status by studying a senior female population and to evaluate predictors of insulin resistance and malnutrition. A total of 88 elderly females were enrolled prospectively with a median age of 75 years. Anthropometric and biochemical parameters (fasting glucose, insulin, folic acid, vitamin B12 concentrations, lipid profile, complete blood count) were recorded along with a full geriatric assessment, have been made in all participants. A comprehensive nutritional phenotype has been established. Leptin and adiponectin concentrations were measured by applying immunoassay techniques. Lipid profile and other parameters were performed by biochemical methods. We observed significant decreases of albumin, alanine aminotransferase, insulin, and triglycerides concentrations with age. The risk of insulin resistance based on HOMA-IR index was decreased with age. Significantly higher concentrations of leptin, leptin-to-adiponectin ratio (LAR), hsCRP, fasting glucose, insulin in the insulin resistant subgroup in respect of normal sensitivity insulin cases were noted. The concentrations of albumin, aspartate aminotransferase, alanine aminotransferase and total cholesterol were significantly lower in those patients at risk of malnutrition than in the well-nourished subjects. LAR reached the most accurate AUCROC = 0.705 for insulin resistance prediction, with a cut-off value at 3.85. The greatest diagnostic power was presented by the albumin concentration with AUCROC = 0.761 and then LAR 0.718 in discriminating between well-nourished patients and those at risk of malnutrition. We suggest that the leptin-to-adiponectin ratio is suitable as a marker of insulin resistance and nutritional status in the elderly.

Role of glutathione metabolism and glutathione-related antioxidant defense systems in hypertension.

The risk of developing chronic hypertension increases with age. Among others factors, increased oxidative stress is a well-recognized etiological factor for the development of hypertension. The co-occurrence of oxidative stress and hypertension may occur as a consequence of a decrease in antioxidant defense system activity or elevated reactive oxygen species generation. Glutathione is a major intracellular thiol-disulfide redox buffer that serves as a cofactor for many antioxidant enzymes. Glutathione-related parameters are altered in hypertension, suggesting that there is an association between the glutathione-related redox system and hypertension. In this review, we provide mechanistic explanations for how glutathione maintains blood pressure. More specifically, we discuss glutathione's role in combating oxidative stress and maintaining nitric oxide bioavailability via the formation of nitrosothiols and nitrosohemoglobin. Although impaired vasodilator responses are observed in S-nitrosothiol-deficient red blood cells, this potential hypertensive mechanism is currently overlooked in the literature. Here we fill in this gap by discussing the role of glutathione in nitric oxide metabolism and controlling blood pressure. We conclude that disturbances in glutathione metabolism might explain age-dependent increases in blood pressure.

Prohepcidin and iron metabolism parameters in the obese elderly patients with anemia.

OBJECTIVE: To examine the impact of a body fat content on the concentration of a serum prohepcidin, iron metabolism parameters and inflammation markers in elderly patients with microcytic or normocytic anemia. DESIGN: Clinical study with biochemical and anthropometric measurements. SUBJECTS: Fifty two elderly patients (19 male, 33 female) with anemia, 65-91 years of age. MEASUREMENTS: Prohepcidin, ferritin, soluble transferrin receptor, erythropoietin and interleukin-6 were measured using commercially available ELISA kits. Iron, TIBC, transferrin, C-reactive protein and complete blood count were assayed using standard laboratory methods. Body fat content, fat distribution and protein nutrition state parameters were assessed by means of anthropometry. RESULTS: Mean serum prohepcidin levels were significantly higher in patients with high body fat content in comparison to patients with normal body fat content (224,85 vs 176,6 ng/ml). Prohepcidin levels of the elderly patients with anemia were positively correlated with biceps, subscapular and suprailiac skinfold thickness or body fat mass percentage. In our study serum prohepcidin levels do not correlate with any iron parameters or inflammation markers. CONCLUSION: Summing up, the results of this study indicate that increased prohepcidin concentration, observed in obese elderly patients with anemia, may play an important role in iron deficiency development.

Glutathione-related antioxidant defense system in elderly patients treated for hypertension.

The purpose of this study was to analyze glutathione antioxidant defense system in elderly patients treated for hypertension. Studies were carried out in the blood collected from 18 hypertensive and 15 age- and sex-matched controls, all subjects age over 60. Hypertensives were on their usual antihypertensive treatment at the time of blood collection. The concentration of glutathione (GSH) in whole blood and activities of glutathione peroxidase (GPx-1), glutathione transferase (GST), and glutathione reductase (GR) in erythrocytes were measured. The data from patients and controls were compared using independent-samples t test. P value of 0.05 and less was considered statistically significant. We observed increased glutathione-related antioxidant defense in treated hypertensive elderly patients (HT) when compared with healthy controls (C). Mean GSH concentration was significantly higher in HT when compared with C: 3.1 ± 0.29 and 2.6 ± 0.25 mmol/L, respectively, P < 0.001. Mean activity of GR was significantly higher in HT group if compared with C: 83.4 ± 15.25 U/g Hb versus 64.2 ± 8.26 U/g Hb, respectively, P < 0.001. Mean activity of GST was significantly higher in HT group compared with C: 3.0 ± 0.60 mmol CDNB-GSH/mgHb/min and 2.6 ± 0.36 mmol CDNB-GSH/mgHb/min, respectively, P < 0.05. No difference in GPx activity was observed between two groups. These results show that glutathione-related antioxidant defense system was enhanced in elderly hypertensive patients treated for their conditions. This suggests important role of glutathione system in blood pressure regulation. Alterations in concentration and activity of antioxidants observed during antihypertensive medication are likely to be related to the effect of the treatment on NO bioavailability.

Influence of the management of cervical carcinoma on the activity of catalase and glutathione peroxidase in erythrocytes.

PURPOSE OF INVESTIGATION: The aim of the study was to determine the effect of different types of management on the activity of catalase (CAT) and glutathione peroxidase (GPx) in women with cervical carcinoma. METHODS: The patients were divided into three groups according to the mode of treatment. Patients from the first group were treated brachytherapy prior to surgery. The second group received teletherapy before brachytherapy and additionally chemotherapy. The third group was treated with teletherapy after brachytherapy sessions. RESULTS: CAT activity was higher while GPx activity was lower before and during therapy in all groups as compared to controls. Six months after the end of therapy, the activity of studied enzymes reached the values characteristic of healthy women. No significant differences in enzyme activity among the three groups were revealed. CONCLUSION: Normalization of CAT and GPx activity may prove the efficacy of applied therapy in cervical cancer patients, however enzyme activity recovery was not dependent on treatment mode.

The analysis healthy behavior among elderly people in Juczyniski's Inventory of Healthy Behavior.

PURPOSE: The aim of our research was the analysis healthy behavior in people, who continued their education in the third age group at Universities and elderly hospitalized patients. MATERIAL AND METHODS: The study group included students in the third age group at Universities and Senior Clubs and patients hospitalized in the Department and Clinic of Geriatrics, there were 87 women and 37 men, in total 124 people. The mean age of the evaluated people group was 67.6 years. The research was carried out by diagnostic poll method with the application of Juczynski's Inventory of Healthy Behavior (IoHB). RESULTS: The studied people group showed a high level of health behavior, obtaining higher scores than standard for older people. This difference was statistically significant for all studied rates. In our study, the standardized rate was in general 6.50, including 6.39 for women and 6.76 for men. Such rate value of health behavior should be considered as average rather than high. CONCLUSIONS: The older people in the present report have a high level of healthy behavior compared to the average for adult population.

The analysis of dehydroepiandrosterone sulphate concentration in elderly age women depending on coexisting disease states.

PURPOSE: The aim of the study was evaluation of dehydroepiandrosterone sulphate (DHEA-S) serum concentration in elderly women and determining interdependence between DHEA-S levels and occurrence of diseases typical for this period of life. MATERIAL AND METHODS: The study was conducted on 103 elderly women (mean age 70.7 +/- 7.3 years). The control group consisted of 25 young and healthy women (mean age 33.5 +/- 1.7 years). The elderly patients were fully functional, well nourished, and only periodically required medical care due to chronic illnesses such as coronary heart disease, arterial hypertension, type 2 diabetes, osteoporosis, depression. DHEA-S serum concentration was determined by Spectria DHEA(S) RIA radioimmunological kit. Statistically significantly important decrease of DHEA-S serum concentration was determined in elderly women compared with the control group. RESULTS: Mean blood serum DHEA-S concentration in elderly group was significantly lower compared to controls. Mean blood serum DHEA-S concentration was statistically significantly lower in the group of patients suffering from coronary heart disease, osteoporosis, and depression. Statistically significantly lower DHEA-S concentration was observed in patients with benign disorders of cognitive functions and depression compared with patients with correct MMSE and GDS results. CONCLUSIONS: In elderly women DHEA-S concentration can turn out to be useful aging biomarker. Concentration of this hormone significantly decreases together with age, especially with coexisting diseases typical for this period of life.

Process of nursing as an active form nurse's work with patient in therapeutic team--project of evidencing the process of looking after a sick person for students of nursing Faculty of Health Sciences, UMK Collegium Medicum in Bydgoszcz.

In years sixtieth in U.S.A. the process of nursing was introduced to the contemporary practice of nursing. U.S. was also the first country where the need of teaching the nurses on high standard was noticed and executed. In years 1960-1980 a very intensive development of nursing appeared there, the process of nursing strengthened it's position as a work method based on the theory of human's needs. In Poland idea of process of care developed from over twenty years. Instruction cares is based for scientific bases this of process. Process of nursing as dynamic work method, makes a work of nurse very active and raises the quality of care after a sick person. This process embraces with one's own range also healthy man, potentially threatened with disease, family, group of persons and environment. It is the modern form of nursing in the contrary to nursing understood in traditional way. The main purpose of introduction the process of evidencing to execution of classes like geriatrics and geriatric nursing with students of the third year Faculty of Health Sciences, UMK Collegium Medicum was moulding abilities of conducting the process looking after a sick person by students trough underlining the meaning of scientific bases of nursing.

[Evaluation of some selected structural and functional parameters of red blood cells as oxidative stress markers in elderly people]. / Ocena wybranych parametrów strukturalnych i czynnosciowych krwinek czerwonych jako markerów stresu oksydacyjnego u osób w wieku podeszlym.

UNLABELLED: The ageing process induces age-related involutionary changes and leads to increased occurrence of many diseases. One of the most important theories of ageing and development of many pathologies is the free radical theory, which assumes that ageing process leads to lost of oxidative balance. THE AIM: of the research was to evaluate the degree of membrane lipid peroxidation, internal microviscosity, activity of membrane ATPase, both total and Na(+)K(+)-dependent, and markers of oxidative damage in erythrocyte membrane protein in elderly people. MATERIAL: The examination was performed on 35 people. The examined group (15 persons, mean age 71,3) consisted of healthy elderly people. The reference group was formed with younger healthy people (20 persons, mean age 55). RESULTS: Erythrocyte membrane lipid peroxidation was found stronger in the group of elderly people. Erythrocyte internal microviscosity was significantly higher in the elderly. The activity of ATPase, both total and Na(+)K(+)-dependent, appeared remarkably greater in the group of younger people. Stronger membrane lipid damage was observed in older age group, which may be implied by lower--SH group concentration, and higher W/S parameter value. CONCLUSION: The obtained results reveal that in elderly people the intensification of oxidative stress in the entire body occurs, which may be confirmed by structural and functional oxidative erythrocyte damage. This conclusion may be significant for pathogenesis of many diseases in this period of life.

Effect of vitamin E and vitamin C supplementation on antioxidative state and renal glomerular basement membrane thickness in diabetic kidney.

The aim of this study was to analyze the effect of vitamins C and E on malondialdehyde (MDA) content and activities of key antioxidant enzymes: superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) as well as glomerular basement membrane (GBM) thickness in streptozotocin-induced diabetic kidney in rats. Wistar male rats were divided into following groups (12 rats each): the control, diabetic rats, diabetic rats whose drinking water was supplemented with vitamin C in a dose of 1.0 g/l or diet was supplemented with 200 mg of vitamin E/100 g fodder. Body weight, blood glucose and HbA1C levels and 24-hour urinary albumin excretion (UAE) were studied every week (0-12 weeks). After 6 and 12 weeks, MDA content and activities of SOD, CAT and GSH-Px were measured in the kidney homogenate supernatants. Electron micrographs of glomeruli were scanned and morphometric investigations were performed by means of computer image analysis system to compare GBM thickness. The blood glucose and HbA1C concentrations and UAE in diabetic rats were significantly higher than in the control group. An increase in the MDA level and decrease in the SOD, CAT and GSH-Px activities in the kidney of diabetic rats were observed after 6 and 12 weeks of experiment. Administration of vitamins C and E did not affect body weight, blood glucose and HbA1C levels. Both vitamin C and vitamin E decreased lipid peroxidation and augmented the activities of antioxidant enzymes studied in the kidneys of diabetic rats as well as reduced UAE, decreased kidney weight and GBM thickness. The results indicate the potential utility of antioxidant vitamins in the protection against the development of diabetic nephropathy.

The effect of verapamil on the antioxidant defence system in diabetic kidney.

BACKGROUND: The aim of this study was to examine the effect of verapamil (VP) on lipid peroxidation and activities of key antioxidant enzymes: superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px); as well as on glomerular basement membrane (GBM) thickness in streptozotocin-induced diabetic kidney in rats. METHODS: Wistar male rats were divided into three groups, 12 rats each: the control (C), diabetic rats (DR), and DR receiving VP, 7 mg/kg body weight in drinking water (DR + VP). Blood glucose (BG) and HbA(1c) levels, 24-h urinary albumin excretion (UAE) and body weight (BW) were measured every week (0-12 weeks). After 6 and 12 weeks, the animals were sacrificed and malondialdehyde (MDA) content and activities of SOD, CAT and GSH-Px were determined in the kidney homogenate supernatants. Electron micrographs of the glomeruli were scanned and morphometric investigations were performed by means of a computer image analysis system to compare the glomerular basement basal membrane (GBM) thickness. RESULTS: The levels of BG, HbA(1c) and UAE in DR were significantly higher than in the C group. A progressive increase in the MDA level and a decrease in the SOD, CAT and GSH-Px activities in the kidney of DR were observed after 6 and 12 weeks. VP administration did not affect BW changes, BG and HbA(1c) levels in DR. VP decreased lipid peroxidation and augmented the activities of antioxidant enzymes studied in the kidneys of DR as well as decreased kidney weight, GBM thickness and albuminuria in DR. CONCLUSIONS: These results confirm the role of oxidative stress in the development of diabetic nephropathy and point to the possible antioxidative mechanism of the nephroprotective action of VP.

Lipid peroxidation and activities of antioxidant enzymes in the diabetic kidney: effect of treatment with angiotensin convertase inhibitors.

Effects of the angiotensin convertase inhibitors captopril (CAP) and enalapril (ENA) on the malondialdehyde (MDA) content and the activities of superoxide dismutase (SOD) and catalase in the kidneys of rats with streptozotocin-induced diabetes were studied. Induction of diabetes resulted in an increase of MDA concentration and progressive decreases of SOD and catalase activities after 6 and 12 weeks. CAP and ENA administration did not affect body weight changes or blood glucose and HbA1c contents in diabetic rats but decreased albuminuria and kidney weight increase, attenuated lipid peroxidation, and prevented the decreases in SOD and catalase activities. These results confirm the oxidative stress in streptozotocin-induced experimental diabetes and point to the beneficial antioxidant effects of angiotensin convertase inhibitors.

Effect of angiotensin convertase inhibitors and AT1 angiotensin receptor antagonists on the development of oxidative stress in the kidney of diabetic rats.

The aim of this study was to analyse the effect of angiotensin convertase inhibitor, enalapril (ENA), and angiotensin AT-1 receptor antagonist, losartan potassium (LP), on lipid peroxidation and activities of Cu,Zn-superoxide dismutase, catalase and glutathione peroxidase in kidneys of streptozotocin (STZ)-induced diabetic rats after 6 and 12 weeks of treatment. STZ-induced body weight changes and blood glucose concentration were not affected by either ENA or LP but both drugs significantly decreased cholesterol and triglyceride concentrations elevated in diabetic rats, inhibited kidney weight gain, and decreased albuminuria. Kidneys of STZ-diabetic rats had increased malondialdehyde content and decreased activities of antioxidant enzymes (Cu,Zn-superoxide dismutase, catalase and glutathione peroxidase). Both ENA and LP decreased lipid peroxidation and augmented the activities of antioxidant enzymes studied in the kidneys of diabetic rats. These results confirm the role of oxidative stress in the development of diabetic nephropathy already at early stages of the development of diabetes and point to the possible antioxidative mechanism of the nephroprotective action of ENA and LP.

Production of superoxide and nitric oxide by granulocytes in non-insulin-dependent diabetic patients with and without diabetic nephropathy.

Production of the superoxide radical anion O2-. and the nitric oxide radical NO-. by granulocytes was studied in 14 patients with type 2 diabetes without nephropathy, 21 patients with type 2 diabetes and diabetic nephropathy, and 19 healthy subjects, both without and after stimulation with opsonized zymosan. O2-. production by both resting and stimulated granulocytes was increased in type 2 diabetes patients without nephropathy but decreased in type 2 diabetes patients with nephropathy, compared with healthy subjects. NO. generation was highly augmented in type 2 diabetes patients without nephropathy by both resting and stimulated cells; values for type 2 diabetes patients with nephropathy were intermediate between the type 2 diabetes patients without nephropathy and the healthy subjects. These data point to granulocytes as one of possible sources of oxidative stress in type 2 diabetes.

Effect of aminoguanidine on erythrocyte lipid peroxidation and activities of antioxidant enzymes in experimental diabetes.

The effect of aminoguanidine (AG) on the malondialdehyde (MDA) concentration and activities of superoxide dismutase (SOD), catalase and glutathione peroxidase (GSH-Px) in erythrocytes of rats with streptozotocin-induced diabetes was studied. Induction of diabetes resulted in an increase of MDA concentration and decreases of SOD and catalase activities after 6 and 12 weeks. GSH-Px activity increased after 6 weeks and returned to control values after 12 weeks. AG administration did not affect body weight, blood glucose level and HbA1c content in diabetic rats but led to a decrease of MDA concentration and SOD and catalase activities after 12 weeks of treatment, with no significant effect after 6 weeks. AG attenuated the GSH-Px increase after 6 weeks but augmented the activity of this enzyme after 12 weeks. These results confirm the presence of oxidative stress in streptozotocin-induced experimental diabetes and point to the beneficial antioxidant effect of AG.

Effect of aminoguanidine on lipid peroxidation and activities of antioxidant enzymes in the diabetic kidney.

The aim of this study was to examine lipid peroxidation and activities of key antioxidant enzymes in kidneys of rats with streptozotocin (STZ)-induced diabetes and the effect of aminoguanidine on diabetes-induced alterations. Three groups, 6 rats each, were studied: control animals, not treated diabetic rats and rats treated with aminoguanidine (AG; 1 g/liter of drinking water). After 6 and 12 weeks the animals were sacrificed and lipid peroxidation products and activities of antioxidant enzymes were determined in their kidney homogenates. Malondialdehyde (MDA) content was significantly elevated and activities of SOD and catalase decreased in the kidneys of STZ-diabetic rats. AG treatment attenuated the increase in MDA content and diminutions of activities of SOD and catalase in the kidneys of diabetic rats. These results confirm oxidative stress in the kidney of rats with STZ diabetes and point to an antioxidant effect of AG in experimental diabetes.

Lipid peroxidation and activities of antioxidant enzymes in erythrocytes of patients with non-insulin dependent diabetes with or without diabetic nephropathy.

BACKGROUND: Diabetes is known to involve oxidative stress. However, data on oxidative stress in diabetic nephropathy is scant. The aim of this study was to examine lipid peroxidation and activities of key antioxidant enzymes in non-insulin dependent diabetes (NIDDM) without nephropathy and in those with diabetic nephropathy. METHODS: Twenty-one NIDDM outpatients with obvious diabetic nephropathy (persistent proteinuria, over 0.5 g/day and albumin excretion over 200 microg/min), 14 NIDDM outpatients with a long diabetic history but without hypertension and with normal urinary albumin excretion rate (<20 microg/min) and 19 healthy persons were studied. Malondialdehyde (MDA) content of erythrocytes was quantified by HPLC according to Young et al. In erythrocytes, superoxide dismutase (SOD) activity was determined by the adrenaline method of Misra and Fridovich and catalase was estimated according to Beers and Sizer. RESULTS: MDA content was significantly elevated in erythrocytes of NIDDM patients without nephropathy vs the control group and even higher in erythrocytes of NIDDM patients with diabetic nephropathy. SOD and catalase activities were lower in erythrocytes of NIDDM patients without nephropathy than in the control group and lowest in erythrocytes of NIDDM patients with nephropathy. CONCLUSIONS: These results confirm oxidative stress in erythrocytes of NIDDM patients with nephropathy. The intensity of oxidative stress appeared to be greater than in NIDDM patients without nephropathy.

Effect of angiotensin convertase inhibitors on lipid peroxidation and peroxyl radical-trapping capacity in rats with experimental diabetes.

Effect of two angiotensin convertase inhibitors, enalapril and captopril, on blood plasma and erythrocyte lipid peroxidation and plasma peroxyl radical-trapping capacity was studied in rats with streptozotocin-induced diabetes. A progressive increase in blood erythrocyte malondialdehyde (MDA) level was observed in diabetic rats after 6 and 12 weeks. Blood plasma MDA level increased while plasma peroxyl radical-trapping capacity was decreased after 12 weeks. Captopril (2 mg/kg body weight) augmented the diabetes-induced changes in MDA content after 6 weeks and prevented them after 12 weeks increasing also the peroxyl radical-trapping capacity. Enalapril (1 mg/kg body weight) counteracted the diabetes-induced changes in MDA content after both 6 and 12 weeks but did not affect the plasma peroxyl radical-trapping capacity. These results suggest a possibility of a therapeutic use of angiotensin convertase inhibitors to attenuate the effects of oxidative stress in diabetes.

Effect of the H2 histamine receptor antagonist on oxygen metabolism in some morphotic blood elements in patients with ulcer disease.

BACKGROUND/AIMS: Our investigations was carried out in order to examine the effect of cimetidine, ranitidine and famotidine on the generation of free radicals, lipid peroxidation and enzymatic antioxidative defense in the blood of patients with peptic ulcer disease, clinically diagnosed as gastric or duodenal ulcer. METHODOLOGY: 124 non-smoking males (aged 20-51 years), were randomly divided into 4 groups: 28 patients received intravenously 200 mg of cimetidine; 26 patients intravenously 50 mg comprised of ranitidine; 25 patients received intravenously 20 mg of famotidine; and 45 healthy men served as the control group. Superoxide dismutase activity, malonyldialdehyde concentration in blood platelets and superoxide anion generation in granulocytes were determined in all examined men. An assay of superoxide dismutase activity and malonyldialdehyde concentration were performed before drug administration and after 2 and 72 hours. Superoxide anion generation was estimated before drug administration and after 2 hours. RESULTS: Our data indicate that all examined H2 receptor antagonists stimulate superoxide dismutase activity, but after 72 hours a distinct increase was observed, in addition to a decrease of malonyldialdehyde concentration. No differences have been observed in superoxide anion generation in patients with ulcer disease or in healthy subjects before and after ranitidine and famotidine administration. Only after 2 hours of cimetidine administration was a significant increase in superoxide anion generation observed. CONCLUSION: We concluded that H2 receptor antagonists have a beneficial effect on antioxidative processes.

Effect of aminoguanidine on the generation of superoxide anion and nitric oxide by peripheral blood granulocytes of rats with streptozotocin-induced diabetes.

The effect of aminoguanidine (AG) on the production of superoxide anion O2*- and nitric oxide (NO) by peripheral blood granulocytes of rats with streptozotocin-induced diabetes was studied. Induction of diabetes resulted in an increase of O2*-. Generation by both unstimulated and opsonized zymosan-stimulated granulocytes was maximal after 6 weeks and lower after 12 weeks. Treatment with aminoguanidine (1 g/l drinking water) decreased O2*- generation after 6 weeks but not after 12 weeks. NO production by both unstimulated and opsonized zymosan-stimulated granulocytes was elevated in diabetic rats to a comparable extent after 6 and 12 weeks. AG attenuated this increased NO production. These results point to the beneficial effect of AG on oxidative stress in experimental diabetes and suggest an antioxidant effect of AG.