Ozge Cevik

Quercetin protects radiation-induced DNA damage and apoptosis in kidney and bladder tissues of rats

Abstract Ionizing radiation (IR) can induce cell damage and cell death through the reactive oxygen species generated by radiolytic hydrolysis. The present study was aimed to determine the possible protective effects of quercetin, a well-known antioxidant agent, against IR-induced bladder and kidney damage in rats. Sprague-Dawley rats were exposed to 8-Gy whole-abdominal IR and given either vehicle or quercetin (20 mg/kg, ip). Rats were decapitated at either 36 h or 10 days following IR, where quercetin or vehicle injections were repeated once daily, and kidney and bladder samples were obtained for the determination of myeloperoxidase and caspase-3 activities, an index of tissue neutrophil infiltration and apoptosis, respectively. Radiation-induced inflammation was evaluated through tissue cytokine, TNF-α levels. In order to examine oxidative DNA damage, tissue 8-hydroxydeoxyguanosine (8-OHdG) levels were measured. All tissues were also examined microscopically. In the saline-treated irradiation groups, myeloperoxidase and caspase-3 activities, 8-OHdG and TNF-α levels were found to be increased in both tissues (p < 0.05). In the quercetin-treated-IR groups, all these oxidant responses were prevented significantly (p < 0.05). The present data demonstrate that quercetin, through its free radical scavenging and antioxidant properties, attenuates irradiation-induced oxidative organ injury, suggesting that quercetin may have a potential benefit in radiotherapy by minimizing the adverse effects and will improve patient care.

Montelukast inhibits caspase-3 activity and ameliorates oxidative damage in the spinal cord and urinary bladder of rats with spinal cord injury

Spinal cord injury (SCI) leads to an inflammatory response that generates substantial secondary damage within the tissue besides the primary damage. Leukotrienes are biologically active 5-lipoxygenase products of arachidonic acid metabolism that are involved in the mediation of various inflammatory disorders including SCI. In this study, we investigated the possible protective effects of montelukast, a leukotriene receptor blocker, on SCI-induced oxidative damage. Wistar albino rats (n=24) were divided randomly as control, vehicle- or montelukast (10mg/kg, ip)-treated SCI groups. To induce SCI, a standard weight-drop method that induced a moderately severe injury at T10 was used. Vehicle or montelukast were administered to the injured animals 15 min after injury. At seven days post-injury, neurological examination was performed and rats were decapitated. Blood samples were taken to evaluate leukotriene B4 levels, and pro-inflmamatory cytokines (TNF-α, IL-1β) while in spinal cord and urinary bladder samples malondialdehyde (MDA), glutathione (GSH), luminol chemiluminescence (CL) levels and myeloperoxidase (MPO) and caspase-3 activities were determined. Tissues were also evaluated histologically. SCI caused significant decreases in tissue GSH, which were accompanied with significant increases in luminol CL and MDA levels and MPO and caspase-3 activities, while pro-inflammatory cytokines in the plasma were elevated. On the other hand, montelukast treatment reversed these parameters and improved histological findings. In conclusion, SCI caused oxidative tissue injury through the activation of pro-inflammatory mediators and by neutrophil infiltration into tissues, and the neuroprotective and antiapoptotic effects of montelukast are mediated by the inhibition of lipid peroxidation, neutrophil accumulation and pro-inflammatory cytokine release. Moreover, montelukast does not only exert antioxidant and antiapoptotic effects on the spinal cord, but it has a significant impact on the bladder tissue damage secondary to SCI.

Synthesis and characterization of celecoxib derivatives as possible anti-inflammatory, analgesic, antioxidant, anticancer and anti-HCV agents.

A series of novel N-(3-substituted aryl/alkyl-4-oxo-1,3-thiazolidin-2-ylidene)-4-[5-(4-methylphenyl)-3-(trifluoromethyl)-1H-pyrazol-1-yl]benzenesulfonamides 2a–e were synthesized by the addition of ethyl α-bromoacetate and anhydrous sodium acetate in dry ethanol to N-(substituted aryl/alkylcarbamothioyl)-4-[5-(4-methylphenyl)-3-(trifluoro-methyl)-1H-pyrazol-1-yl]benzene sulfonamides 1a–e, which were synthesized by the reaction of alkyl/aryl isothiocyanates with celecoxib. The structures of the isolated products were determined by spectral methods and their anti-inflammatory, analgesic, antioxidant, anticancer and anti-HCV NS5B RNA-dependent RNA polymerase (RdRp) activities evaluated. The compounds were also tested for gastric toxicity and selected compound 1a was screened for its anticancer activity against 60 human tumor cell lines. These investigations revealed that compound 1a exhibited anti-inflammatory and analgesic activities and further did not cause tissue damage in liver, kidney, colon and brain compared to untreated controls or celecoxib. Compounds 1c and 1d displayed modest inhibition of HCV NS5B RdRp activity. In conclusion, N-(ethylcarbamothioyl)-4-[5-(4-methylphenyl)-3-(trifluoromethyl)-1H-pyrazol-1-yl]benzenesulfonamide (1a) may have the potential to be developed into a therapeutic agent.

Beneficial effects of quercetin on rat urinary bladder after spinal cord injury

BACKGROUND Spinal cord injury (SCI) leads to an inflammatory response and generates oxidative stress, which has deleterious effects on the function of several organ systems, including the urinary bladder. The present study was designed to investigate the putative beneficial effect of quercetin against SCI-induced bladder damage. MATERIALS AND METHODS In order to induce SCI, a standard weight-drop method that induced a moderately severe injury (100 g/cm force) at T10 was used. Injured animals were given either 20 mg/kg quercetin or vehicle 15 min post injury and repeated twice daily for 7 d. After decapitation, bladder strips were placed in organ bath and isometric contractions to carbachol (10(-8) to10(-4) M) were recorded. In order to examine oxidative tissue injury, luminol chemiluminescence, nitric oxide, malondialdehyde, and glutathione levels and superoxide dismutase, myeloperoxidase, and caspase 3 activities of bladder tissues were measured along with histologic evaluations. Proinflammatory cytokines tumor necrosis factor α, interleukin 1β, and interleukin 6 were also assayed in blood samples. RESULTS In the injured animals, the contractile responses of the bladder strips were lower than those of the control group and were reversed by treatment with quercetin. On the other hand, increase in nitric oxide, malondialdehyde, luminol chemiluminescence levels, and myeloperoxidase and caspase 3 activities of tissues in the SCI group were significantly reversed by quercetin treatment. Similarly, plasma cytokine levels, which were elevated in the vehicle-treated SCI group, were reduced with quercetin treatment. Furthermore, treatment with quercetin also prevented the depletion of tissue glutathione levels and superoxide dismutase activity seen in the SCI group. CONCLUSIONS According to the results, quercetin exerts beneficial effects against SCI-induced oxidative damage through its anti-inflammatory and antioxidant effects.

Investigation of acetylcholinesterase and mammalian DNA topoisomerases, carbonic anhydrase inhibition profiles, and cytotoxic activity of novel bis(α-aminoalkyl)phosphinic acid derivatives against human breast cancer

The aim of this study was to evaluate biologically active novel molecules having potentials to be drugs by their antitumor properties and by activities of apoptotic caspase and topoisomerase. Following syntheses of novel eight bis(α‐aminoalkyl)phosphinic acid derivatives (4a–h) as a result of array of reactions, compounds were evaluated by cytotoxic effects in vitro on human breast cancer (MCF‐7) and normal endothelial (HUVEC) cell lines. All phosphinic acid derivatives were effective for cytotoxicity on both MCF‐7 and HUVEC lines, while 4c, 4e, and 4f compounds were found significantly more effective. For the evaluation of antitumor properties of compounds in a highly sensitive method, their effects on inhibiting topoisomerases I and II were investigated. Also, some of the bis(α‐aminoalkyl)phosphinic acid derivatives (4a, 4e–h) showed nice inhibitory action against acetylcholinesterase and human carbonic anhydrase isoforms I and II.

Quercetin treatment against ischemia/reperfusion injury in rat corpus cavernosum tissue: a role on apoptosis and oxidative stress

Abstract Reactive oxygen metabolites play an important role in the ischemia/reperfusion (I/R)-induced tissue injury. This study was designed to investigate the possible protective effects of quercetin against I/R injury of the rat corpus cavernosum tissue. To induce I/R injury, abdominal aorta was clamped for 30 min and reperfused for 60 min. Quercetin (20 mg/kg) or vehicle was given before ischemia and just after reperfusion in the I/R group and in the sham-operated control group in which clamping was not performed. After decapitation, corpus cavernosum tissues were removed and either placed in organ baths or stored for evaluating biochemical parameters. Oxidative injury was examined by measuring lucigenin chemiluminescence (CL), nitric oxide (NO), malondialdehyde (MDA) and glutathione (GSH) levels, superoxide dismutase (SOD) and myeloperoxidase (MPO) activities and caspase-3 protein levels. In the I/R group, contractile responses to phenylephrine and relaxation responses to carbachol were impaired significantly compared with those in the control groups, while quercetin treatment in I/R group reversed both of the responses. On the other hand, increase in lucigenin CL, NO, MDA levels and MPO and caspase-3 activities and decrease in GSH levels and SOD activity in the cavernosal tissues of the I/R group were also significantly reversed by quercetin treatment. Furthermore, observed distorted morphology with ruptured endothelial cells and vacuolization in the cytoplasm of cavernosal tissues of I/R no longer persisted in the quercetin-treated I/R group. Thus, our results suggested that treatment with quercetin may have some benefits in controlling I/R-induced tissue injury through its anti-inflammatory, anti-apoptotic, and antioxidant effects.

Melatonin and tadalafil treatment improves erectile dysfunction after spinal cord injury in rats

Oxidative stress plays an important role both in spinal cord injury (SCI) and erectile dysfunction (ED). The present study investigated the effects of melatonin and tadalafil treatment alone or in combination on SCI‐induced ED. Male Wistar albino rats (n = 40) were divided into five groups: sham‐operated control and SCI‐injured rats given either vehicle, melatonin (10 mg/kg, i.p.), tadalafil (10 mg/kg, p.o.) or a combination of melatonin and tadalafil. Spinal cord injury was induced using a standard weight‐drop method. On Day 7 after SCI, intracavernosal pressure (ICP) was measured and all rats were decapitated. Cavernosal tissues were obtained to examine caspase 3, nitric oxide synthase (NOS), myeloperoxidase (MPO) and superoxide dismutase (SOD) activities, as well as cGMP, nerve growth factor (NGF), malondialdehyde (MDA) and glutathione (GSH) levels. Spinal cord injury caused oxidative damage, as evidenced by increases in MDA and cGMP levels. In addition, MPO and caspase 3 activites were increased after SCI, whereas GSH and NGF levels and SOD activity were reduced. Melatonin effectively reversed these oxidative changes. Furthermore, in rats treated with both melatonin and tadalafil, the recoveries were more pronounced than in rats given either melatonin or tadalafil alone. The ICP/mean arterial pressure value in vehicle‐treated SCI rats was significantly higher than in the control group, whereas in the tadalafil‐ and tadalafil + melatonin‐treated groups have returned this value had returned to control levels. As an individual treatment, and especially when combined with tadalafil, a well‐known agent in the treatment of ED, melatonin prevented SCI‐induced oxidative damage to cavernosal tissues and restored ED, most likely due to its anti‐oxidant effects.

WISP1 is a novel adipokine linked to metabolic parameters in gestational diabetes mellitus.

Abstract Objective: To investigate Wnt1-inducible signaling pathway protein-1 (WISP1) levels and their correlation with metabolic parameters in pregnant women with gestational diabetes mellitus (GDM) and non-GDM healthy pregnant women. Materials and Methods: In this prospective cross-sectional study, the study group was composed of 62 women with GDM and 73 healthy pregnant women matched for age, body mass index (BMI) and gestational age. Blood samples were collected at 25–29th gestational week. Serum WISP1, betatrophin, glucose, fasting insulin, glycosylated hemoglobin A1c, total cholesterol, triglyceride, high density lipoprotein cholesterol, low density lipoprotein cholesterol, C reactive protein, alanine aminotransferase and creatinine levels were measured. Homeostasis model assessment of insulin resistance (HOMA-IR) values was calculated. The level of significance was accepted as p < 0.05. Results: Circulating WISP1 in the GDM group was significantly higher than the control group (p <0.001). Further, WISP1 was positively correlated with BMI, HOMA-IR values and fasting glucose, fasting insulin, triglyceride, betatrophin levels. BMI, HOMA-IR and betatrophin independently and positively predicted WISP1 levels. Conclusion: These results demonstrate a relationship between WISP1 and the metabolic parameters of GDM. And, WISP1 might be involved in the pathophysiology of GDM. As a part of this pathophysiological mechanism, the activation of WISP1 and betatrophin might take place through several ways; WISP1 and betatrophin might either use same signaling pathways and potentiate each other or they might also constitute the sequential steps of a common pathway.

Investigation into the role of the cholinergic system in radiation-induced damage in the rat liver and ileum

It has been previously shown that acetylcholine (ACh) may affect pro-inflammatory and anti-inflammatory cytokines. The role of the cholinergic system in radiation-induced inflammatory responses and tissue damage remains unclear. Therefore, the present study was designed to determine the radio-protective properties of the cholinergic system in the ileum and the liver of rats. Rats were exposed to 8-Gy single-fraction whole-abdominal irradiation and were then decapitated at either 36 h or 10 d post-irradiation. The rats were treated either with intraperitoneal physiological saline (1 ml/kg), physostigmine (80 µg/kg) or atropine (50 μg/kg) twice daily for 36 h or 10 d. Cardiac blood samples and liver and ileal tissues were obtained in which TNF-α, IL-1β and IL-10 levels were assayed using ELISA. In the liver and ileal homogenates, caspase-3 immunoblots were performed and myeloperoxidase (MPO) activity was analyzed. Plasma levels of IL-1β and TNF-α increased significantly following radiation (P < 0.01 and P < 0.001, respectively) as compared with non-irradiated controls, and physostigmine treatment prevented the increase in the pro-inflammatory cytokines (P < 0.01 and P < 0.001, respectively). Plasma IL-10 levels were not found to be significantly changed following radiation, whereas physostigmine augmented IL-10 levels during the late phase (P < 0.01). In the liver and ileum homogenates, IL-1β and TNF-α levels were also elevated following radiation, and this effect was inhibited by physostigmine treatment but not by atropine. Similarly, physostigmine also reversed the changes in MPO activity and in the caspase-3 levels in the liver and ileum. Histological examination revealed related changes. Physostigmine experiments suggested that ACh has a radio-protective effect not involving the muscarinic receptors.

Estrogen receptor agonists alleviate cardiac and renal oxidative injury in rats with renovascular hypertension

ABSTRACT Although endogenous estrogen is known to offer cardiac and vascular protection, the involvement of estrogen receptors in mediating the protective effect of estrogen on hypertension-induced cardiovascular and renal injury is not fully explained. We aimed to investigate the effects of estrogen receptor (ER) agonists on oxidative injury, cardiovascular and renal functions of rats with renovascular hypertension (RVH). Female Sprague-Dawley rats were randomly divided as control and RVH groups, and RVH groups had either ovariectomy (OVX) or sham-OVX. Sham-OVX-RVH and OVX-RVH groups received either ERβ agonist diarylpropiolnitrile (1 mg/kg/day) or ERα agonist propyl pyrazole triol (1 mg/kg/day) for 6 weeks starting at the third week following the surgery. At the end of the 9th week, systolic blood pressures were recorded, cardiac functions were determined, and the contraction/relaxation responses of aortic rings were obtained. Serum creatinine levels, tissue malondialdehyde, glutathione, superoxide dismutase, catalase levels, and myeloperoxidase activity in heart and kidney samples were analyzed, and Na+, K+-ATPase activity was measured in kidney samples. In both sham-OVX and OVX rats, both agonists reduced blood pressure and reversed the impaired contractile performance of the heart, while ERβ agonist improved renal functions in both the OVX and non-OVX rats. Both agonists reduced neutrophil infiltration, lipid peroxidation, and elevated antioxidant levels in the heart, but a more ERβ-mediated protective effect was observed in the kidney. Our data suggest that activation of ERβ might play a role in preserving the function of the stenotic kidney and delaying the progression of renal injury, while both receptors mediate similar cardioprotective effects.