Eda Dokumacioglu

The effect of hesperidin and quercetin on oxidative stress, NF-κB and SIRT1 levels in a STZ-induced experimental diabetes model.

OBJECTIVE The aim of this study is to investigate the roles of SIRT1 and NF-κB in the pathogenesis of diabetes mellitus in rats with STZ-induced diabetes and determine the effects of hesperidin and quercetin on oxidative stress and on the levels of SIRT1 and NF-κB. MATERIALS AND METHODS The experimental animals were divided into four groups, each group comprising ten rats designated as follows: group 1 served as control rats (C); group 2 served as diabetic rats (DM); group 3 served as diabetic rats administered hesperidin (DM+HSP) (100mg/kg b.w.) in aqueous suspension orally for 15 days; and group 4 served as diabetic rats administered quercetin (DM+Q) (100mg/kg b.w.) in aqueous suspension orally for 15 days. RESULTS In diabetic group, liver and kidney SIRT1, SOD and CAT activities were significantly lower than control group (p<0.05). Hesperidin and quercetin caused significant increase in the SIRT1, SOD and CAT activities of both DM+HP and DM+Q groups kidney tissues compared to DM group (p<0.05). Liver SOD activies were not found to differ significantly between DM, DM+Q and DM+HP groups (p>0.05). In DM+HP group, liver CAT activities were significantly higher than DM (p<0.05), but there was no significant difference in liver CAT activities between DM and DM+Q (p>0.05). In diabetic group, liver and kidney NF-κB and MDA levels were increased compared to control group (p<0.05), and groups of DM+HP and DM+Q had lower NF-κB and MDA levels than diabetic group (p<0.05). CONCLUSION As a conclusion, based on the results we obtained from this study and the literature data discussed above, we determined in STZ-induced diabetic rats that, increased glucose levels and liver and kidney damage markers decreased significantly after administration of hesperedin and quercetin, and that oxidative stress and NF-κB levels increased while SIRT1 levels decreased in the diabetic group.

The Effects of Dietary Flavonoid Supplementation on the Antioxidant Status of Laying Hens

ABSTRACT Ninety-six 28-week-old Lohmann White laying hens were utilized to test the antioxidant effects of flavonoids (hesperidin, naringin, and quercetin at 0.5 g/kg diet) during an 8-wk experimental period. At the end of the experiment blood samples were collected to determine total protein, cholesterol, and malondialdehyde (MDA) serum levels as well as activities of glutathione reductase (GR), glutathione peroxidase (GSH-Px), glutathione- S -transferase (GST), and superoxide dismutase (SOD) and level of glutathione (GSH) in erythrocyte lysates. Data were analyzed using one-way ANOVA. Naringin supplementation did not alter serum cholesterol concentration, whereas hesperidin and quercetin supplementations decreased serum cholesterol concentration. Naringin and quercetin supplementations did not affect serum protein concentration. All flavonoids decreased MDA concentration as well as increased GSH-Px, GR, GST, and SOD activities and GSH level, being quercetion superior to hesperidin and naringin. In conclusion, flavonoids, especially quercetin, exert antioxidant activity, which may help improve wellbeing when laying hens are exposed to stressors.

Comparison of the effects of dietary supplementation of flavonoids on laying hen performance, egg quality and egg nutrient profile

ABSTRACT 1. The aim of this experiment was to compare the effects of dietary supplementation of hesperidin, naringin and quercetin on laying hen performance, egg quality and egg yolk lipid and protein profiles. 2. A total of 96 Lohmann White laying hens weighing an average of 1500 g at 28 weeks of age were randomly assigned to a basal diet and the basal diet supplemented (0.5 g/kg) with either hesperidin, naringin or quercetin. Each treatment was replicated in 6 cages in an 8-week experimental period. Data were analysed using one-way analysis of variance. 3. None of the dietary flavonoids affected laying performance and eggshell quality. Hesperidin and quercetin supplementations decreased albumen and yolk indexes. 4. As compared to the control group, egg yolk cholesterol content decreased and egg yolk protein content increased in response to dietary hesperidin and quercetin supplementation. The mean egg yolk cholesterol (mg/g) and protein (g/100 g) contents were 10.08/14.28, 16.12/14.08, 14.75/15.04 and 15.15/14.85 for the control group and groups supplemented with naringin, hesperidin and quercetin, respectively. 5. Egg yolk lipid and protein profiles were variable. 6. In conclusion, dietary supplementation of hesperidin or quercetin could be used in the diets during the early laying period to reduce egg yolk cholesterol and increase egg yolk protein, which may be attractive to consumers.

Serum apelin and ADMA levels in type 2 diabetics with and without vascular complications

AIMS Type 2 diabetes mellitus (T2DM) is a metabolic and chronic disease which is characterized by hyperglycemia, and that is the major causes of various micro and macrovascular complications. Asymmetrical dimethylarginine (ADMA), formed by the hydrolysis of proteins containing methylated arginine residues, is an endogenous inhibitor of nitric oxide synthase (NOS), which oxidize l-arginine to citruline and nitric oxide (NO), related to hyperinsulinaemia and hyperlipidaemia. Apelin is a recently discovered peptide, present in a number of tissues and play role in insulin sensitivity improvement. In this study, our aim was to determine the levels of apelin and ADMA with glycated haemoglobin (HbA1c) in type 2 diabetic patients with or without vascular complications. METHODS This study included (a total of) 59 diabetic patients. Of the patients, 30 were diabetic with complications, and 29 without complications. In serum samples obtained from the patients, serum ADMA and apelin levels were measured with Enzyme Linked Immunosorbent Assay (ELISA) method. RESULTS Our study totally enrolled 59 patients in two groups. No significant differences were found in sex, age, HbA1c and glucose levels among groups. Apelin and ADMA levels of group with complications were lower than those of group without complications, but no statistically significant difference of apelin and ADMA levels (p>0.05). CONCLUSION The results of this study have been showed no statistically significant relationship present between ADMA-apelin levels and complications of T2DM. Further studies involving larger patients populations and healthy controls should be done to clarify the pathogenetic significance of apelin and ADMA in diabetic vascular complications.

The effects of hesperidin and quercetin on serum tumor necrosis factor-alpha and interleukin-6 levels in streptozotocin-induced diabetes model

Background: Diabetes mellitus (DM) is a metabolic disorder that occurs as a result of absolute or relative insufficiency of insulin release and/or insulin effect due to impairment of carbohydrate, fat and protein metabolism, and it is characterized by hyperglycemia and leads to various complications. Objective: In this study, it was aimed to investigate the effects of hesperidin (HP) and quercetin, which are natural flavonoids, on serum malondialdehyde (MDA), glutathione (GSH), tumor necrosis factor alpha (TNF-α), and interleukin-6 (IL-6) levels in rats with streptozotocin (STZ)-induced diabetes. Materials and Methods: The experimental animals were divided into four groups, each group comprising ten rats designated as follows: Group 1 served as control rats (C); Group 2 served as diabetic rats (DM); Group 3 served as diabetic rats administered HP (DM + HP) (100 mg/kg b. w.); and Group 4 served as diabetic rats administered quercetin (DM + Q) (100 mg/kg b. w.). Results: Serum MDA and GSH levels were significantly higher in STZ-induced DM group than control group (P < 0.05). In DM + HP and DM + Q groups, MDA levels were significantly decreased compared to DM groups (P < 0.05), but there was no significant difference GSH levels between DM, DM + HP, and DM + Q groups (P > 0.05). TNF-α levels in STZ-induced DM group were significantly decreased compared to control group (P < 0.05), and groups of DM + HP and DM + Q had higher serum TNF-α levels than STZ-induced DM group (P < 0.05). In STZ-induced DM group, serum IL-6 levels were decreased compared to control group (P < 0.05). Conclusion: As a result, in this study, we determined that HP and quercetin may play an effective role in regulating insulin metabolism metabolism in diabetes. However, considering the incompatibility of various results in the literature as well as our own results, we think that the actual role of cytokines in the pathogenesis of diabetes is one of the issues that need to be clarified in further studies. Abbreviations used: DM: Diabetes mellitus, MDA: Malondialdehyde, GSH: Glutathione; IL-6: Interleukin-6, TNF-α: Tumor necrosis factor alpha, HP: Hesperidin, Q; Quercetin, STZ: Streptozotocin, TC: Total cholesterol, TG: Triglyceride, HDL-C: High density lipoprotein cholesterol, LDL-C: Low density lipoprotein cholesterol, VLDL-C: Very-low-density lipoprotein cholesterol.

Measuring urinary 8-hydroxy-2′-deoxyguanosine and malondialdehyde levels in women with overactive bladder

Purpose In this study, we aimed to explain the role of oxidative stress in women with overactive bladder (OAB) by investigating the levels of 8-hydroxy-2′-deoxyguanosine (8-OHdG), a marker of oxidative DNA damage, and malondialdehyde (MDA), an indicator of lipid peroxidation. Materials and Methods A total of 90 women were included in the study: 45 female patients diagnosed with OAB at Hopa State Hospital Urology Polyclinic and 45 healthy women without any metabolic or neurologic disease. Levels of MDA and 8-OHdG were measured in 24-hour urine samples for all subjects. Results Urinary levels of MDA and 8-OHdG were significantly higher in the OAB group than in the control group (p<0.001). A significant positive correlation (p<0.001) was found between the measurements of 8-OHdG and MDA. Conclusions Oxidative stress may be important in the pathophysiology of OAB, because levels of 8-OHdG and MDA are increased. Increased levels of 8-OHdG may be due to damaged nuclear and mitochondrial DNA as a result of oxidative attacks caused by free radicals. Nevertheless, further randomized and prospective studies with larger patient populations are needed.

Astaxanthin alleviates renal damage of rats on high fructose diet through modulating NFκB/SIRT1 pathway and mitigating oxidative stress

Abstract This study was conducted to determine the effect of astaxanthin (ASX) treatment on alleviation of renal damage in high fructose induced nephrotoxicity in rats. Treatments were arranged in a 2 × 2 factorial fashion: administrations of fructose (30%, via drinking water) and ASX (1 mg/kg/day, within 0.2 ml olive oil) for 8 weeks. Data were analyzed by two-way ANOVA. The ASX treatment decreased serum urea (p < .01) and blood urea–N concentrations (p < .02) at a lower extent in rats receiving fructose than those not receiving fructose. Moreover, the ASX treatment reversed the increases in malondialdehyde (MDA) (p < .0001) and nuclear factor kappa B (NF-κB) (p < .0003) levels and the decreases in superoxide dismutase (SOD) activity (p < .0001) and sirtuin-1 (SIRT1) level (p < .0004), in the kidney upon high fructose consumption. The data suggest that ASX supplementation alleviates renal damage induced by high fructose consumption through modulating NF-κB/SIRT1 pathway and mitigating oxidative stress.

Effects of astaxanthin on biochemical and histopathological parameters related to oxidative stress on testes of rats on high fructose regime

Astaxanthin (ASX) is a xanthophyll family of hydroxycarotenoids which contains several double bonds. It is produced by Haemococcus pluvialis, a microalgae and possesses antioxidant and anti‐inflammatory properties. The aim of this study was to test whether ASX could protect against oxidative damage in the testicular tissues of rats receiving high fructose. The rats (n = 24) were randomly divided into two main groups: control and fructose (30%, via drinking water) and then each main group either not supplemented or supplemented with ASX (1 mg kg−1 day−1, within 0.2 ml olive oil) via oral gavage. Data were subjected to two‐way ANOVA. High fructose consumption tended to increase testis weight and serum testosterone concentration and decreased testicular tissue glutathione‐S‐transferase (GST) and superoxide dismutase (SOD) levels, but did not affect testicular tissue malondialdehyde (MDA) concentration. Astaxanthin administration increased testosterone, GST and SOD levels and testis weight and decreased MDA concentration. However, ASX administration did not reverse alterations in antioxidant parameters caused by high fructose consumption. Inducible nitric oxide synthase (iNOS) tended to increase in sertoli cell, spermatid and spermatogonia, but not in spermatocytes and leydig cell in response to high fructose consumption. Astaxanthin administration tended to reverse elevation in iNOS in testis cells. In conclusion, ASX could help alleviate oxidative damage caused by high fructose consumption.

A Retrospective Study from Turkey: Assessment of first Application Findings of Children with Type 1 Diabetes Diagnosis in Ordu

Objective: Type 1 diabetes mellitus (T1DM) is one of the most common chronic endocrine diseases encountered in childhood and adolescent periods. This study aims to assess the biochemical and epidemiological characteristics of children monitored for T1DM diagnosis in Ordu. Methods: This study investigated some biochemical and epidemiological characteristics of a total of 40 (20 boys, 20 girls) children ranging in age from 3 to 16 years with first diagnosis and follow-up at Ordu University Faculty of Medicine Education and Research Hospital Pediatric Health and Diseases Department from 2012 to 2016. Children participating in the study were divided into 2 groups as aged 3-9 years and 10-16 years. Group I included children aged from 3-9 years, while Group II included children aged from 10-16 years. The distribution according to gender and peak age for first diagnosis were examined. The study retrospectively investigated the fasting plasma glucose, HbA1C, AST, ALT, Na, K, Cl, triglyceride, cholesterol, BUN, creatinine, white cells, hemoglobin, urine pH, urine density, urine glucose, blood pH and HCO3 values of pediatric patients applying for the first time and receiving diagnosis of T1DM. Results: Our patients included 20 girls (50%) and 20 boys (50%). The lowest diabetes age was 3 years with highest 16 years. According to age distribution of patients, the peak age of disease was 11 years (22.5%) and there were 17 patients (42.5%) in the 3-9 age group and 23 (57.5%) in the 10-16 age group. When biochemical parameters are compared in terms of gender, the TG value in girls (104.9 ± 42.9) was found to be statistically significantly high compared to the TG value for boys (68.3 ±17.2) (p<0.05). However, there was no other statistically significant difference identified for any other biochemical parameter in terms of gender. Conclusion: It is accepted that the incidence of T1DM is increasing globally and the age of diagnosis is falling. Early diagnosis and developing effective treatment of T1DM patients is very important in terms of preventing possible complications.