Azibe Yildiz

The Protective Effects of Apocynin on Kidney Damage Caused by Renal Ischemia/Reperfusion

PURPOSE This experimental study was designed to explore the protective effect of apocynin, the NADPH-oxidase inhibitor, on kidney damage induced by ischemia/reperfusion (I/R) in a rat model. METHODS Thirty-two rats were randomly divided into a control group and three I/R groups (1-hour ischemia followed by 23-hour reperfusion). Three I/R groups were treated by apocynin (20 mg/kg, i.p.) at two different time points (before ischemia and during ischemia). The histopathological findings, including apoptotic changes, and also tissue malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathion peroxidase (GPX), reduced glutathione (GSH), myeloperoxidase (MPO), blood urea nitrogen (BUN), and serum creatinine (Cr) levels, were determined. RESULTS Kidney tissue MDA and MPO, and serum BUN and Cr levels were found to be significantly higher in the I/R group, but there was no statistically significant difference in the levels of SOD, CAT, GPX, and GSH between the I/R and the control groups. Although apocynin significantly reduced MDA and MPO in group 3 and increased GPX in both treatment groups when compared to the I/R group, the elevated BUN and Cr levels were significantly reduced in treatment groups. Renal I/R injury also induced extensive tubular necrosis, glomerular damage, and apoptosis in the histological evaluation. Apocynin, especially when used during ischemia, ameliorated these histological damages in different amounts in treatment groups. CONCLUSION The beneficial effects of apocynin on renal I/R injury were evaluated for the first time.

The Protective Effect of Apocynin on Testicular Ischemia-Reperfusion Injury

PURPOSE We investigated the protective effect of the NADPH oxidase inhibitor apocynin on testicular damage induced by ischemia-reperfusion injury in rats. MATERIALS AND METHODS A total of 32 rats were randomly divided into 4 groups. Controls underwent left scrotal exploration only. The 3 groups with ischemia-reperfusion underwent 4-hour torsion followed by 1-hour detorsion. The ischemia-reperfusion only group underwent left testicular torsion and detorsion. The ischemia-reperfusion plus saline group underwent left testicular torsion, received 10 ml/kg saline intraperitoneally at minute 210 of ischemia and then underwent detorsion. The ischemia-reperfusion plus apocynin group underwent left testicular torsion, received 20 mg/kg apocynin intraperitoneally at minute 210 of ischemia and then underwent detorsion. We determined histopathological findings and performed specific biochemical analyses. RESULTS In the ischemia-reperfusion only and the ischemia-reperfusion plus saline groups malondialdehyde, total oxidative capacity and the oxidative stress index were significantly higher. Superoxide dismutase, catalase, glutathione peroxidase and glutathione were significantly lower. Apocynin significantly decreased malondialdehyde, total oxidative capacity and the oxidative stress index, and significantly increased superoxide dismutase and catalase. There was a significantly increase in the number of giant, degenerated and desquamated cells in the ischemia-reperfusion group. Apocynin significantly improved these histological alterations. CONCLUSIONS These histopathological and biochemical findings show the beneficial effects of apocynin on testicular ischemia-reperfusion injury.

Protective Effects of Apocynin on Cisplatin-induced Hepatotoxicity in Rats

BACKGROUND AND AIMS Despite it being a highly potent antineoplastic drug, cisplatin has important toxic adverse effects limiting its use such as nephrotoxicity, neurotoxicity and ototoxicity. It is thought that cisplatin-induced hepatotoxicity is caused by oxidative stress resulting from increased reactive oxygen species (ROS). Apocynin (APO) exerts its antioxidant effect by reducing ROS production via inhibition of NADPH oxidase. The present study intended to demonstrate effects of cisplatin on hepatic pro-oxidant/antioxidant systems and to investigate protective effects of APO against cisplatin-induced hepatotoxicity. METHODS Rats were randomly assigned into four groups (n = 8 each): a) control group; b) single dose of cisplatin (5 mg/kg); c) APO group (20 mg/kg on three consecutive days; i.p.); and d) APO plus cisplatin group. Liver tissue was assessed in all groups by biochemical and histopathological means. Also, serum alanine transaminase (ALT), aspartate transaminase (AST) and alkaline phosphatase levels were studied in all groups. RESULTS When cisplatin group was compared to controls, it was seen that lipid peroxidation product, total oxidant status and ALT levels were markedly increased, whereas superoxide dismutase and glutathione peroxidase levels were overtly decreased. APO therapy markedly prevented cisplatin-induced harmful changes in liver. Our histopathological findings such as central vein dilatation, perivenuler and periportal sinusoidal dilatation, parenchymal inflammation, vacuolar changes in hepatocytes, biliary duct proliferation and caspase-3 positive hepatocytes were in accordance with the biochemical changes. CONCLUSION In light of these results, it is our thought that APO has a protective role against cisplatin-induced hepatotoxicity at both biochemical and histopathological levels.

Melatonin's protective effect on the salivary gland against ionized radiation damage in rats

OBJECTIVES The aim of this study was to examine the effects of melatonin on ionized radiation-induced salivary gland damage using an experimental model. MATERIALS AND METHODS Thirty-two rats were randomized into four groups: (i) the control group (C, n = 8) that received intraperitoneal (i.p.) 0.9% NaCl; (ii) the melatonin group (M, n = 8) that received i.p. 5 mg/kg melatonin; (iii) the radiotherapy group (RT, n = 8) that underwent irradiation; (iv) the melatonin plus radiotherapy group (M+RT, n = 8) that received i.p. 5 mg/kg of melatonin, followed by irradiation 30 min later; and (v) the radiotherapy plus melatonin group (RT+M, n = 8) that received irradiation followed by i.p. 5 mg/kg of melatonin 30 min later. The medications and irradiation were administered for 5 days and the salivary glands of the rats were excised 10 days later; the histopathological changes in the salivary glands were assessed and biochemical analyses were conducted (tissue levels of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), reduced glutathione (GSH), total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI)). RESULTS Regardless of whether melatonin was administered before or after radiotherapy, melatonin decreased the radiation-induced parotid and submandibular histological damage. In addition, regardless of whether administration occurred before or after radiotherapy, melatonin decreased oxidative stress markers, such as MDA, TOS, and OSI. On the contrary, levels of antioxidative markers, such as CAT and GPx, were increased by melatonin. CONCLUSIONS Melatonin may have a significant protective effect on salivary gland damage secondary to ionizing radiation.

Ameliorative effects of aminoguanidine on rat aorta in Streptozotocin-induced diabetes and evaluation of α-SMA expression.

OBJECTIVE Diabetes mellitus is one of the chronic metabolic diseases which is characterized by microvascular and macrovascular complications. This study was designed to investigate the improving the effects of amnioguanidine on aortic damage in a streptozotocin (STZ) induced diabetic rat model. METHODS Thirty-two male Sprague-Dawley rats divided into four groups as follows: Control, Aminoguanidine, Diabetes, and Diabetes+Aminoguanidine. Experimental diabetes was induced by single dose STZ (45 mg/kg) intraperitoneally. After administration of STZ, the DM+AMG group began to receive AMG (1 g/L) was prepared by dissolving in tap water during 10 weeks. At the end of the study, blood glucose levels were determined and rats were sacrified by ketamine anesthesia. Following routine tissue process, aortas were embedded in paraffin. Histochemical (H-E and Orcein) and immunohistochemical α-smooth muscle actin (α-SMA) stains were applied and the sections examined by light microscope. Statistical analysis was carried out using the SPSS 13.0 statistical program. RESULTS The rats in diabetes group had significantly higher blood glucose levels than the rats of control. The main histological alterations were detected in tunica media such as extensive thickening (414.32±9.62 μm), irregular of elastic fibers and intensive α-SMA staining in diabetic rats. The thickness of tunica media was statistically increased in DM group, when compared with the control group (p<0.001). On the other hand, AMG prevented disorganization of elastic fibers and overexpression of α-SMA. The mean thickness of tunica media was decreased significantly in DM+AMG (319.16±6.53 μm) compared with the DM group (p<0.001). CONCLUSION Our results demonstrate that AMG treatment may protect the impairment of aort structure at histological level.

Inhibition of NADPH oxidase by apocynin promotes myocardial antioxidant response and prevents isoproterenol-induced myocardial oxidative stress in rats

Abstract Preventive and/or therapeutic interventions for ischemic heart disease have gained considerable attention worldwide. We investigated the mechanism(s) underlying cardioprotection of apocynin (APO) and whether it attenuates isoproterenol (ISO)-induced myocardial damage in vivo. Thirty-two male Wistar Albino rats were randomised into four groups (n = 8 for each group): Group I (Control); Group II (ISO), ISO was given intraperitoneally (ip) (150 mg/kg/d) daily for 2 consecutive days; Group III (APO + ISO), APO was applied ip 20 mg/kg 30 min before the first ISO administration and continued for the next 2 d after the second ISO administration; Group IV (ISO + APO), after the ISO treatment on days 1 and 2, 20 mg/kg APO was given ip on days 3 and 4. Cardioprotective effects of APO were evaluated by biochemical values, histopathological observations and the antiapoptotic relative proteins. Mean blood pressure, heart rate, and electrocardiography (ECG) were also monitored. Malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), total oxidant status (TOS), total antioxidant capacity (TAC), oxidative stress index (OSI), caspase-3 and connexin 43 levels were determined. Major ECG changes were observed in the ISO-treated rats. MDA, TOS, OSI and creatine kinase levels decreased and SOD, CAT, GSH and TAC levels increased, indicating that APO reduced cardiac injury and oxidative stress compared with controls. APO also decreased the number of cardiomyocytes with pyknotic nuclei, inflammatory cell infiltration, intracytoplasmic vacuolisation and myofibrils. APO provides preventive and therapeutic effects on ISO-induced myocardial injury in rats by inhibiting reactive oxygen species production, blocking inflammation and enhancing antioxidant status.

The effect of melatonin on acetylsalicylic acid-induced kidney and testis damage

The aim of this study was to evaluate the acute effect of high-dose acetylsalicylic acid (ASA) on kidney and testis, and the potential protective and therapeutic effects of melatonin on ASA-related pathology. A total of 40 rats were randomly divided into the following 5 groups (n = 8): group 1: control, not given any drug; group 2: only 200 mg/kg ASA was given; group 3: 5 mg/kg melatonin was given 45 min before administering 200 mg/kg ASA; group 4: 5 mg/kg melatonin was given 45 min after administering 200 mg/kg ASA; and group 5: only 5 mg/kg melatonin was given. The histopathological changes and the biochemical findings; such as malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), reduced glutathione (GSH), and blood urea nitrogen (BUN) as well as serum creatinine (Cr) levels were evaluated. ASA significantly increased MDA levels in both kidney and testis, whereas it significantly decreased the values of SOD, CAT, GPX, and GSH in kidney and CAT levels in testis. Melatonin significantly decreased MDA levels in kidney and ameliorated it in testis, whereas it caused elevation in the levels of antioxidants. BUN and Cr levels were higher after ASA, whereas these levels were diminished after melatonin administration. The improvement obtained by melatonin on ASA-induced histological alterations was more prominent when it was used after ASA in kidney and before ASA in testis. In this study, we demonstrated the beneficial effect of melatonin on high-dose ASA-related pathology of kidney and testis for the first time.

Effects of Molsidomine on Retinopathy and Oxidative Stress Induced by Radiotheraphy in Rat Eyes

ABSTRACT Purpose: To determine the role of Molsidomine in preventing radiation-induced retinopathy after head and neck region irradiation of rats with a single radiation dose of 15 Gy. Materials and Methods: Male Wistar albino rats were randomly grouped into five as follows: (1) control group rats, which were applied through an intraperitoneal (i.p.) vehicle without radiotherapy (RT); (2) RT group rats received a single dose of 15 Gy irradiation and after daily 0.1 ml vehicle i.p. for 5 consecutive days; (3) molsidomine (MOL) group rats were treated for 5 consecutive days by i.p. with 4 mg/kg/day MOL; (4) irradiation plus MOL group (RT+MOL) rats received irradiation and after 10 days single daily i.p. dose of MOL for 5 consecutive days; and (5) MOL+RT group rats were treated for 5 consecutive days by i.p. with MOL before RT. At the end of the work the rats were sacrificed under high-dose anesthesia on the 16th day and then eye tissues were taken for histopathological, immunohistochemical (caspase-3), and biochemical analyses (superoxide dismutase [SOD], glutathione peroxidase [GSH], and malondialdehyde [MDA]). Results: RT significantly decreased both the content of GSH and the activity of SOD, and significantly increased the production of MDA level in the rat eyes. MOL treatment significantly increased the SOD and GSH levels and significantly decreased the MDA production (p < 0.0001). In addition, RT significantly increased the number of ganglion cells (GCs; p = 0.001), whereas especially pretreatment with MOL improved (p = 0.013). RT led to significant retinopathy formation, and MOL therapy protected the retina from radiation-induced retinopathy (p < 0.0001). Conclusions: We suggest that MOL is a powerful antioxidant and free radical scavenger that prevents the rat eyes from radiation-induced retinopathy and oxidative stress.

Beneficial effects of dexpanthenol on mesenteric ischemia and reperfusion injury in experimental rat model

ABSTRACT Background and aim It has been reported that intestinal ischemia–reperfusion (I/R) injury results from oxidative stress caused by increased reactive oxygen species. Dexpanthenol (Dxp) is an alcohol analogue with epitelization, anti-inflammatory, antioxidant, and increasing peristalsis activities. In the present study, the aim was to investigate protective and therapeutic effects of Dxp against intestinal I/R injury. Materials and methods Overall, 40 rats were assigned into five groups including one control, one alone Dxp, and three I/R groups (40-min ischemia; followed by 2-h reperfusion). In two I/R groups, Dxp (500 mg/kg, i.m.) was given before or during ischemia. The histopathological findings including apoptotic changes, and also tissue and serum biochemical parameters levels, were determined. Oxidative stress and ileum damage were assessed by biochemical and histological examination. In the control (n = 8) and alone Dxp (n = 8; 500 mg/kg, i.m. of Dxp was given at least 30 min before recording), groups were incised via laparotomy, and electrical activity was recorded from their intestines. In this experiment, the effect of Dxp on the motility of the intestine was examined by analyzing electrical activity. Results In ileum, oxidant levels were found to be higher, while antioxidant levels were found to be lower in I/R groups when compared with controls. Dxp approximated high levels of oxidants than those in the control group, while it increased antioxidant values compared with I/R groups. Histopathological changes caused by intestinal I/R injury and histological improvements were observed in both groups given Dxp. In the Dxp group, electrical signal activity markedly increased compared with the control group. Conclusions Here, it was seen that Dxp had protective and therapeutic effects on intestinal I/R injury and gastrointestinal system peristaltism.

Maternal viral mimetic administration at the beginning of fetal hypothalamic nuclei development accelerates puberty in female rat offspring

This study aimed to investigate the effects of maternal viral infection during a critical time window of fetal hypothalamic development on timing of puberty in the female offspring. For that purpose, a viral mimetic (i.e., synthetic double-strand RNA, namely, polyinosinic-polycytidylic acid, poly (I:C)) or saline was injected (i.p.) to the pregnant rats during the beginning (day 12 of pregnancy, n = 5 for each group) or at the end of this time window (day 14 of pregnancy, n = 5 for each group). Four study groups were formed from the female pups (n = 9-10 pups/group). Following weaning of pups, vaginal opening and vaginal smearing was studied daily until 2 sequential estrous cycles were observed. During the second diestrus phase, blood samples were taken for progesterone, leptin, corticosterone, follicle-stimulating hormone, and luteinizing hormone. Maternal poly (I:C) injection on day 12 of pregnancy increased body mass and reduced the time to puberty in the female offspring. Neither poly (I:C) nor timing of injection affected other parameters studied (p > 0.05). It has been shown for the first time that maternal viral infection during the beginning of fetal hypothalamic development might hasten puberty by increasing body mass in rat offspring.