Ahmet Gurel

Protective effects of thymoquinone against apoptosis and oxidative stress by arsenic in rat kidney

Abstract We aimed to investigate the protective role of thymoquinone (TQ) by targeting its antiapoptotic and antioxidant properties against kidney damage induced by arsenic in rats. We have used the 24 male Sprague-Dawley rats. Rats were divided into three groups. Physiological serum in 10 mL/kg dose as intragastric was given to the control group. Sodium arsenite (10 mg/kg, intragastric by gavage for fifteen days) was given to the arsenic group. Sodium arsenite (10 mg/kg, intragastric by gavage for fifteen days) and TQ (10 mg/kg, intragastric by gavage for 15 days) was given to the arsenic + TQ group. After 15 days, the animals’ kidneys were taken theirs, then we have performed histological and apoptotic assessment. Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) enzyme activities and malondialdehyde (MDA) levels have examined as the oxidative stress parameters. We have determined the levels of arsenic. Increased renal injury and apoptotic cells have been detected in the arsenic group. Degenerative changes in the arsenic + TQ group were diminished. Although the MDA levels were augmented in the arsenic group, SOD, CAT and GSH-Px enzyme activities were lessened than the other groups. Our findings suggest that TQ may impede the oxidative stress, the cells have been damaged and also the generation of apoptotic cells arisen from arsenic. TQ plays a protective role against arsenic-induced toxicity in kidney and may potentially be used as a remedial agent.

The Effects of Quercetin on Acute Lung Injury and Biomarkers of Inflammation and Oxidative Stress in the Rat Model of Sepsis

Experimental studies indicate that sepsis causes remote organ injury although the molecular mechanism has not been clearly defined. In this report, the role of oxidative damage, and inflammation on lung injury, following sepsis model by cecal ligation and puncture, and the effects of quercetin, antioxidant, and anti-inflammatory flavonoid, in the lung tissue were investigated. In the present study, we found that administration of single-dose quercetin before cecal ligation and puncture procedure, while markedly diminishing the levels of YKL-40 and oxidant molecules (xanthine oxidase (XO), nitric oxide (NO), and malondialdehyde (MDA)), increases the antioxidant enzymes levels. Quercetin is beneficial to acute lung injury by decreasing the levels of oxidative stress markers and increasing the antioxidant enzyme activities. Quercetin also causes a decrease in the serum levels of YKL-40 and periostin in the oxidative lung injury induced by the experimental sepsis model.

Asymmetric dimethylarginine contributes to airway nitric oxide deficiency in patients with COPD.

Asymmetric dimethylarginine (ADMA) and nitric oxide (NO) show their mechanism of action reciprocally, the balance between these molecules contributes to the tight regulation of airways tone and function.

The protective effects of ω-3 fatty acids on doxorubicin-induced hepatotoxicity and nephrotoxicity in rats

This study aims to evaluate the protective effects of ω-3 fatty acids (FAs) on doxorubicin (DOX)-induced hepatotoxicity and nephrotoxicity in rats. A total of 24 adult male Sprague Dawley rats were divided into three groups. Control group was given only saline by intragastric gavage. DOX group received DOX at the dose of 30 mg/kg intraperitoneally on day 28. DOX-ω-3 FA group was given as ω-3 FAs at the dose of 400 mg/kg daily by intragastric gavage for 30 days and received DOX at the dose of 30 mg/kg intraperitoneally on day 28. At the end of the 30-day experimental period, the serum, liver and kidney tissue specimens were taken from the animals by giving a general anesthesia. Glutathione (GSH) and malondialdehyde (MDA) levels in serum and GSH and MDA levels and superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in liver and kidney tissues were measured spectrophotometrically. In our study, a significant increase in MDA levels was observed in rats when given a dose of DOX and a significant decrease in the levels of GSH, SOD and GSH-Px activities in serum, liver and kidney tissues was determined when compared with control group. In addition, a significant decrease in MDA levels was observed in rats when a dose of ω-3 FAs was given with DOX and a significant increase was determined in the levels of GSH, SOD and GSH-Px activities in serum, liver and kidney tissues, when compared with DOX group. We concluded that ω-3 FA had favorable effects in rat liver and kidney tissues by preventing oxidative damage.

The role of oxidants and reactive nitrogen species in irritable bowel syndrome: A potential etiological explanation

Background The aim of this study was to evaluate the plasma concentrations of malondialdehyde (MDA) and nitric oxide (NO) and the plasma activities of oxidant and antioxidant enzymes in patients with IBS. Material/Methods A total of 36 patients with IBS were included in the study. Thirty-five healthy subjects were selected to form the control group. Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), xanthine oxidase (XO), adenosine deaminase (AD) activities, and malondialdehyde (MDA) and nitric oxide (NO) concentrations were studied in the serum samples of all patients and controls. Results Plasma XO and AD activities, and MDA and NO concentrations were significantly higher in IBS patients than in controls. The SOD, CAT, and GSH-Px activities in the serum of patients with IBS were significantly lower than that of controls. Conclusions These results suggest that lipid peroxidation and alterations in the oxidant-antioxidant enzymatic system may play a role in the pathogenesis of IBS. Increased lipid peroxidation in IBS may be related to an increase in NO level and XO activity and a decrease in antioxidant enzymes activities. In addition, increased AD activity may have a role in immunological changes of IBS patients.

The Effects of Ferulic Acid Against Oxidative Stress and Inflammation in Formaldehyde-Induced Hepatotoxicity

This study was designed to elucidate the protective effects of ferulic acid (FA) on formaldehyde-induced hepatotoxicity by measuring some routine biochemical parameters, cytokine levels, and oxidative stress-related parameters in addition to YKL-40 in male Wistar albino rats. Tissue superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) activities, and tissue malondialdehyde (MDA) levels were measured. Also, serum YKL-40, TNF-α, IL-6, IL-1β, IL-8, total protein, albumin, total bilirubin concentrations, and AST, ALT, ALP, and LDH activities were measured. Histological specimens were examined in light microscopy. Formaldehyde significantly increased tissue MDA, and serum cytokine levels and also decreased activities of antioxidant enzymes. FA treatment decreased MDA and cytokine levels and increased activities of antioxidant enzymes. FA also alleviated degeneration due to formaldehyde toxicity. We suggested that FA can be used as a promising hepatoprotective agent against formaldehyde toxicity because of the obvious beneficial effects on oxidative stress parameters.