Semra Doğru Abbasoğlu

The effect of heme oxygenase-1 induction by octreotide on radiation enteritis

Radiation enteritis occurs as a response to abdominal radiation, which can cause mucosal damage in the gastrointestinal mucosal epithelium. The small intestine is one of the most radiosensitive organs in the abdomen. The present study was undertaken to investigate the effect of octreotide (OCT) administration on heme oxygenase-1 (HO-1) expression of the radiation enteritis model. Rats received 50 mg/kg/day OCT for 4 days before irradiation and continued for 3 days after irradiation. Intestinal myeloperoxidase (MPO) activities, malondialdehyde (MDA) levels are indicators of oxidative damage while caspase-3 activities reveal apoptosis degree of the small intestine. At histological examination, the terminal ileum tissue was analyzed for morphological changes. Irradiation significantly increased the intestinal MPO and caspase-3 activities, MDA levels and HO-1 expression in comparison to sham control group. OCT treatment was associated with increased HO-1 expression and caspase-3 activity, decreased MPO activity and MDA levels. Histological examination revealed that the intestinal mucosal structure was preserved in the OCT treated group. OCT appears to have protective effects against radiation-induced intestinal damage. This protective effect is, in part, mediated by modification of the inflammatory response and the induction of HO-1 expression.

Effect of heme oxygenase‐1 induction by octreotide on TNBS‐induced colitis

Background and Aim:  Ulcerative colitis is a chronic inflammatory disease of the colon and rectum. Although the precise etiology of ulcerative colitis remains unknown, it is believed to involve an abnormal host response to endogenous or environmental antigens, genetic factors, and oxidative damage. The aim of the present study was to investigate whether heme oxygenase‐1 (HO‐1) induction by octreotide could protect against oxidative and inflammatory damage from induced colitis.

Heme Oxygenase-1 Prevents Hyperthyroidism Induced Hepatic Damage via an Antioxidant and Antiapoptotic Pathway

BACKGROUND The exact pathogenesis of hepatic dysfunction in hyperthyroidism is still unknown. We aimed to investigate the pathogenesis of liver dysfunction caused by hyperthyroidism through inducing heme oxygenase-1 (HO-1) expression, which has antioxidant and anti-apoptotic properties. METHODS Rats were divided into six groups: untreated (group 1), treated with zinc protoporphyrin (ZnPP) (group 2), treated with hemin (group 3), treated with tri-iodothyronine (T3) (group 4), treated with T3 and ZnPP (group 5), and treated with T3 and hemin (group 6). After 22 d, oxidative stress and antioxidant enzymes and the expression of HO-1, mitochondrial permeability transition, cytochrome c, Bax, Bcl-2, caspase-3, caspase-8, and caspase-3 activity, and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay were examined. RESULTS Hyperthyroidism induced oxidative stress of liver tissue was ameliorated by HO-1 induction. Administration of hemin (HO-1 inducer) increased Bcl-2 expression. Decreased expression of cytochrome c was accompanied by a decrease in caspase-3, caspase-8, Bax expression, and caspase-3 activity. The apoptotic activity and oxidative damage were found to be increased by the administration of ZnPP (HO-1 inhibitor). Immunohistochemistry findings supported these results. CONCLUSION HO-1 induction plays a protective role in the pathogenesis of the liver dysfunction in hyperthyroidism. This effect is dependent on modulation of the antiapoptotic and antioxidative pathways by HO-1 expression.

Evaluation of adrenomedullary function in patients with congenital adrenal hyperplasia.

Background/Aims: Congenital adrenal hyperplasia (CAH) is characterized by adrenal insufficiency with or without salt wasting. It is also accompanied by adrenomedullary hypofunction. The aim of the present study was to investigate adrenomedullary function in patients with CAH due to 21-hydroxylase and 11β-hydroxylase deficiencies and in age-matched normal subjects. Methods: We measured plasma catecholamines (epinephrine and norepinephrine) and urine metanephrine in 44 patients with CAH, 32 due to 21-hydroxylase deficiency (17 patients with the salt-wasting form and 15 patients with the simple virilizing form), and 12 due to 11β-hydroxylase deficiency, and in 25 healthy controls. Results: Plasma epinephrine and urine metanephrine levels were significantly higher in the controls than in patients with CAH (p = 0.02 and p < 0.001, respectively). Plasma norepinephrine levels were significantly lower in the controls than in patients with CAH (p < 0.001). Interestingly, patients with the salt-wasting form had lower norepinephrine levels in comparison to the other subgroups of CAH. Conclusion: Despite the fact that CAH patients have insufficient epinephrine secretion, these patients have the ability to increase compensatory norepinephrine. However, this increase is much lower in patients with the salt-wasting form. These findings need to be confirmed by other studies.

Carnosine decreased oxidation and glycation products in serum and liver of high-fat diet and low-dose streptozotocin-induced diabetic rats

High‐fat diet (HFD) and low‐dose streptozotocin (STZ)‐treated rats provide useful animal model for type II diabetes mellitus. Oxidative stress and advanced glycation end products (AGEs) play a role in the development of diabetic complications. Carnosine (CAR) has anti‐oxidant and anti‐glycating properties. We investigated the effects of CAR on oxidation and glycation products in HFD+STZ rats. Rats were fed with HFD (60% of total calories from fat) for 4 weeks, and then a single dose of STZ (40 mg/kg; i.p.) was applied. Rats with blood glucose levels above 200 mg/dl were fed with HFD until the end of the 12th week. CAR (250 mg/kg body weight; i.p.; five times a week) was administered to the rats for the last four weeks. CAR significantly decreased serum triglyceride (TG) (57.7%), cholesterol (35.6%) levels and hepatic marker enzyme activities of HFD+STZ rats. It significantly reduced serum reactive oxygen species (ROS) (23.7%), AGEs (13.4%) and advanced oxidized protein products (AOPP) (35.9%) and hepatic TG (59%), ROS (26%), malondialdehyde (MDA) (11.5%), protein carbonyl (PC) (19.2%) and AGE (20.2%) levels. Liver steatosis and hepatocyte ballooning were also significantly reduced. However, CAR treatment did not alter serum glucose and blood glycated haemoglobin and hepatic anti‐oxidant enzyme activities/mRNA expressions in HFD+STZ rats. Our results indicate that CAR decreased accumulation of oxidation and glycation products, such as MDA, AGE, AOPP and PC in the serum and liver and ameliorated hepatic dysfunction in HFD+STZ rats. This effect may be related to its anti‐oxidative, anti‐glycating, and anti‐lipogenic potential.

Antioxidant Effects of Probiotics in Experimentally Induced Peritonitis

AIM An experimental study was performed to evaluate the protective effects of probiotics on gut mucosa in peritonitis through antioxidant mechanisms. METHODS Thirty-two male Wistar albino rats were divided equally into four groups. The rats in Group 1 (control group) underwent laparotomy only. In group 2 (peritonitis group), peritonitis was induced in the rats by the cecal ligation and puncture (CLP) model. In group 3, the rats were treated with probiotics for five days after CLP-induced peritonitis. The last group of rats (group 4) were fed probiotics for five days before the CLP procedure and five days after the surgery. On the fifth day after surgery, all rats were killed, and tissue samples from the terminal ileum were obtained to evaluate the activities of myeloperoxidase (MPO), malondialdehyde (MDA), and glutathione (GSH). Histopathologic examinations were also performed to evaluate the grade of intestinal injury. RESULTS Myeloperoxidase and MDA activities were increased, GSH concentrations were decreased in group 2, compared with group 1. Intestinal MPO activities in group 4 were decreased compared with group 1 and group 2, indicating a reduction in oxidant activity. Malondialdehyde decreased in group 3 and decreased even more in group 4, compared with the peritonitis group (group 2). Glutathione concentrations were increased in group 4 compared with group 2 and group 3 (p < 0.05). The Chiu scores of the probiotics groups, groups 3 and 4, were lower than those in group 2, indicating reduced mucosal damage in the probiotically fed groups. CONCLUSION Probiotics have protective effects in peritonitis, which may be related to antioxidant mechanisms. This antioxidant effect of probiotics might occur when pre-conditioning with probiotics before peritonitis because there is sufficient time to prepare the tissues for oxidative damage.

High circulating levels of sICAM-1 and sVCAM-1 in the patients with Hashimoto’s thyroiditis

ABSTRACT Objective: To investigate whether soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) levels are increased in euthyroid patients with Hashimoto’s thyroiditis (HT) and whether they are associated with thyroid autoimmunity and metabolic parameters. Design: Cross-sectional. Subjects and Methods: In total, 80 euthyroid patients with HT and 80 age- and body mass index (BMI)-matched control participants were included. Serum sICAM-1, sVCAM-1, free triiodothyronine (fT3), free thyroxine (fT4), thyroid-stimulating hormone (TSH), thyroid peroxidase antibody (anti-TPO), thyroglobulin antibody (anti-TG), fasting blood glucose (FBG), insulin, and lipid levels and homeostasis model assessment for insulin resistance (HOMA-IR) were assessed in all participants. Results: The patients with HT had significantly higher levels of sICAM-1 and sVCAM-1 than controls (both p < 0.001). The difference was sustained after adjustment for TSH and levothyroxine use. Regression analysis demonstrated that sICAM-1 was related to anti-TPO (p < 0.001), and sVCAM-1 was related to both anti-TPO and-TG (p < 0.001 and p = 0.03, respectively); this relationship was sustained after adjustment for age and BMI. Although FBG and HOMA-IR were higher in the HT group, logistic regression analysis revealed that there was no effect of anti-TPO, anti-TG, sICAM-1, sVCAM-1, and C-reactive protein (CRP) on the occurrence of high FBG and high HOMA-IR. Conclusion: sICAM-1 and sVCAM-1 levels were significantly elevated in the patients with euthyroid HT and correlated closely with thyroid autoimmunity. However, soluble adhesion molecules had no relation with glucose metabolism parameters in the HT patients.