Cadmium-induced oxidative stress in Prussian carp (Carassius gibelio Bloch) hepatopancreas: ameliorating effect of melatonin

The oxidative status of the hepatopancreas of Prussian carp females (Carassius gibelio) co-exposed to sublethal cadmium in water and melatonin was studied. The activities of antioxidant enzymes such as glutathione reductase (GR), glutathione peroxidase (GPx), and superoxide dismutase (SOD) as well as the concentration of reduced glutathione (GSH) were measured in homogenates of the hepatopancreas. Furthermore, concentrations of cadmium (Cd), zinc (Zn), copper (Cu), and iron (Fe) in the hepatopancreas were assayed. These females received melatonin implants and were exposed to 0.4 mg/L or 4.0 mg/L Cd in water for either a 13- or a 7-week period, followed by further 6 weeks of purification in clear water. Exposure to Cd influenced the increase in this metal concentration in fish hepatopancreas. In contrast, the fish exposed to cadmium with additional administration of melatonin had a lower accumulation of this metal. Exposure to Cd caused the increase in GSH content and the activity of GR, and a reduction in GPx activity, whereas the SOD activity varies depending on the exposure time on cadmium. In the hepatopancreas of fish treated with Cd alone, the content of Cu and Zn were increased and that of Fe was changed. After melatonin administration to Cd-exposed fish, a decrease in copper and zinc hepatopancreas content was noted. The present findings imply that melatonin co-treatment can effectively protect the fish against the toxic effects of cadmium on endogenous antioxidant status in hepatopancreas tissues and variations in metal concentration, such as Zn, Cu, and Fe.

Nitric oxide synthase in diabetic rat testicular tissue and the effects of pentoxifylline therapy

Diabetes is known to be associated with erectile dysfunction, retrograde ejaculation, level of testicular hormone, and a decrease in semen quality, respectively. In this project, we aimed to investigate at the molecular level, the effects of NOS on testes pathology in diabetes and examine the effects of pentoxifylline on healing. A total of 50 Wistar albino male rats were divided into five groups: Group I control; Group II only diabetes; Group III and IV diabetes + pentoxifylline; Group V only pentoxifylline. Group III rats received 50 mg/kg/day pentoxifylline during two months. In comparison, Group IV rats received saline in the first month followed by 50 mg/kg/day of pentoxifylline for the following month. NOS expression in testicular tissue was assessed using qRT-PCR, western blot, and immunohistochemistry. The mean seminiferous tubule diameter, Johnsen's testicular biopsy score, and serum testosterone levels decreased compared to controls. In contrast, the number of apoptotic cells, the levels of nNOS, iNOS and eNOS mRNA, and protein increased when compared to the control. Upon pentoxifylline therapy NOS decreased suggesting that it contributes to this damage and treatment with pentoxifylline may be effective in reversing this damage.

Protecting the BBB endothelium against cigarette smoke-induced oxidative stress using popular antioxidants: Are they really beneficial?

Blood Brain Barrier (BBB) exposed to realistic concentrations (comparable to a chronic heavy smoker) of Cigarette Smoke Extract (CSE) triggers a strong endothelial inflammatory response which can lead to the onset of neurological disorders. The involvement of Reactive Oxygen Species (ROS) in this inflammatory cascade is evident from the up-regulation of nuclear factor erythroid 2 related factor 2 (Nrf-2), a transcription factor involved in anti-oxidant response signaling in CSE exposed endothelial cells. We have shown that pre-treatment with α-tocopherol and/or ascorbic acid is highly protective for the BBB, thus suggesting that, prophylactic administration of antioxidants can reduce CSE and/or inflammatory-dependent BBB damage. We have assessed and ranked the protective effects of 5 popular OTC antioxidants (Coenzyme Q10, melatonin, glutathione, lipoic acid and resveratrol) against CSE-induced BBB endothelial damage using hCMEC/D3 cells. The analysis of pro-inflammatory cytokines release by ELISA revealed that resveratrol, lipoic acid melatonin and Co-Q10 inhibited the BBB endothelial release of pro-inflammatory cytokines IL-6 and IL-8, reduced (not Co-Q10) CSE-induced up-regulation of Platelet Cell Adhesion Molecule-1 (PECAM-1), Vascular Cell Adhesion Molecule-1 (VCAM-1) & E-selectin and inhibited monocytes-endothelial cell adhesion. The anti-inflammatory effects correlated with the anti-oxidative protection endowed by these compounds as evidenced by upregulation of NADPH: Quinone Oxidoreductase 1 (NQO1) and reduced cellular oxidative stress. CSE-induced release of Vascular Endothelial Growth Factor (VEGF) was inhibited by all tested compounds although the effect was not strictly dose-dependent. Further in vivo studies are required to validate our results and expand our current study to include combinatorial treatments.

Therapeutic effects of pentoxifylline on diabetic heart tissue via NOS

Objective:

Diabetes mellitus causes a decrease in cardiac output, arterial blood pressure, and heart rate. In this study, we aimed to investigate, at the molecular level, the effect of nitric oxide synthase (NOS) on heart pathology in type 1 diabetes and look at the therapeutic effect of pentoxifylline on this pathology.

Methods:

In this experimental study, 50 Wistar albino male rats were used. The rats were divided into 5 groups: group C, control; group D, only diabetes; group D+PI and D+PII, diabetes + pentoxifylline; group P, only pentoxifylline. Group D+PI rats received 50 mg/kg/day pentoxifylline over two months. However, group D+PII rats received saline in the first month and 50 mg/kg/day of pentoxifylline over the following month. At the end of two months, NOS expressions in heart tissue were assessed through immunohistochemistry analysis. The data were compared by one-way ANOVA.

Results:

At the end of the experiments, there was increased cytoplasmic vacuolization, myofibrillar loss, cytoplasmic eosinophilia, and degeneration of cardiomyocytes; nNOS and iNOS expressions in group D decreased compared with that in group C. In group D+PI and group D+PII, nNOS and iNOS expressions improved compared with group D.

Conclusion:

As a result, we found that diabetes, a known chronic disease, causes serious damage in heart tissue. NOS plays a role in this damage, and pentoxifylline aided in improving nNOS and iNOS expression in this damage.

Protective effects of grape seed extract on cadmium-induced testicular damage, apoptosis, and endothelial nitric oxide synthases expression in rats

This study aims to evaluate the protective effect of grape seed proanthocyanidin extract (GSPE) on cadmium (Cd)-induced testicular apoptosis, endothelial nitric oxide synthases (eNOS) expression, and toxicity in rats. A total of 24 male Wistar rats were divided into four groups, namely, control, Cd (2.5 mg/kg), Cd + GSPE (100 mg/kg/day), and GSPE. Spermatogenesis and mean seminiferous tubule diameter were significantly decreased in the Cd groups. Furthermore, the GSPE-treated animals showed an improved histological appearance in the Cd group. The immunoreactivity of eNOS and the number of apoptotic cells were increased in Cd group. Our data indicate a significant reduction of terminal deoxynucleotide transferase-mediated 2'-deoxyuridine 5'-triphosphate nick end-labeling staining and a decrease in the expression of eNOS in the testes tissue of the Cd group treated with GSPE therapy. Therefore, our results suggest that GSPE acts as a potent protective agent against Cd-induced testicular toxicity in rats.

Melatonin and vitamin C ameliorate alcohol-induced oxidative stress and eNOS expression in rat kidney

OBJECTIVES

The aim of this study was to investigate the preventive effects of melatonin and vitamin C as antioxidants on renal injury in chronic alcohol consumption.

MATERIALS AND METHODS

A total of 24 adult male Wistar rats weighing 200-250 g were used in the study. Rats were divided into four equal groups. Group I (control): rats were not fed on alcohol; Group II: rats were fed on alcohol; Group III: rats were fed on alcohol and 40 mg/kg vitamin C; and Group IV: rats were fed on alcohol and 4 mg/kg melatonin.

RESULTS

Light microscopic examination revealed atrophic renal corpuscles, dilatation and congestion of the peritubular vessels, and renal corpuscles with obscure Bowman's space and a few foamy-appearing tubules due to alcohol consumption were observed. Expression of endothelial nitric oxide synthase (eNOS) was localized to glomerulus, distal, and collector tubules. eNOS staining decreased in alcohol treatment group and melatonin and vitamin C encore increased expression pattern of eNOS. Alcohol consumption increased malondialdehyde (MDA) level and superoxide dismutase (SOD) and catalase (CAT) activities significantly in the alcohol consumption groups compared with that in the control group, while in melatonin give group just MDA level was decreased statistically significant and SOD and CAT activities were also decreased numerically compared with the alcohol consumption groups.

CONCLUSIONS

These results indicated that chronic alcohol consumption caused renal damage by increased lipid peroxidation and melatonin and vitamin C administration produced in some degree protection against alcohol-induced damage.

Subacute effect of cigarette smoke exposure in rats: protection by pot marigold (Calendula officinalis L.) extract

This study was carried out to determine the preventive effect of Calendula officinalis L. (pot marigold) on rats exposed to cigarette smoke (CS). Rats were divided into three groups as control, CS and CS + pot marigold (PM). The rats in the CS and CS + PM groups were subjected to CS for 1 h twice a day for 23 days. PM (100 mg/kg body weight) was given to rats in the CS + PM group by gavage, 1 h before each administration period. While malondialdehyde, protein carbonyl contents and reduced glutathione level of the CS group increased, their levels diminished by PM administration. In addition, glutathione peroxidase (GPx), superoxide dismutase activities and β-carotene, vitamins A and C levels decreased in the CS group compared to control, however activities of these enzymes and concentration of vitamins were elevated by PM supplementation. This investigation showed that administration of PM supplied relative protection against subacute CS-induced cell injury.

The effect of resveratrol in tracheal tissue of rats exposed to cigarette smoke

OBJECTIVE

The aim of this study was to evaluate the effect of resveratrol on the tracheal tissue of rats exposed to cigarette smoke.

MATERIALS AND METHODS

40 adult Wistar albino rats were divided into four groups for an experiment of 6 weeks. Animals in group 1 were controls (n = 10). Rats in group 2 were exposed to cigarette smoke only, and rats in group 3 received daily intraperitoneal injections of resveratrol (10 mg/kg/d). Animals in group 4 were exposed to both cigarette smoke and intraperitoneal injections of resveratrol. Rats of all groups were sacrificed using cervical dislocation. The tracheas were removed and embedded in paraffin blocks. Sections of 4-5 mum thickness were prepared from the blocks. These sections were stained with hematoxylin and eosin, periodic acid-Schiff, and Alcian blue and viewed with a Leica DFC 280 light microscope.

RESULTS

Tracheal sections showed that, in group 2 (cigarette smoke group), there was desquamation of epithelial cells into the tracheal lumen, loss of cilia in the epithelial layer, an increase of goblet cells, activation of serous glands at the submucosa, and cell infiltration. In group 4 (cigarette smoke + resveratrol group), all these findings also existed but only a few sections were affected. It was observed that cigarette smoking caused morphological changes such as epithelial degeneration in the upper airway. These morphological changes were correlated with the amount of toxic substances in the cigarette smoke.

CONCLUSION

We found that resveratrol had a preventive role in the histopathological changes caused by cigarette smoking in the rat trachea.

Effect of resveratrol on tubular damage and interstitial fibrosis in kidneys of rats exposed to cigarette smoke

The aim of this study was to evaluate the effect of resveratrol on kidney tissue of rats exposed to cigarette smoke. Forty adult male Wistar Albino rats were divided into four groups. Animals in group 1 was the control group. For 6 weeks, group 2 was exposed to cigarette smoke; group 3 received daily intraperitoneal injections of resveratrol (10 mg/kg/d); and group 4 was exposed to both cigarette smoke and intraperitoneal resveratrol. All rats were sacrificed with cervical dislocation. The kidney tissues were obtained, fixed in Bouin's fixative and embeded in paraffin blocks. Samples were sectioned to 4-5 microns thickness, stained with hematoxylin/eosin (H/E), Masson's trichromic, periodic acid-schiff (PAS) and were examined by light microscopy for tubular injury and interstitial fibrosis. Results were compared by non-parametric tests. Hydropic degeneration, tubular atrophy, tubulo-interstitial fibrosis, interstitial cell infiltration, vacuolar degeneration and desquamation were prominent in group 2. In group 4, hydropic degeneration, epithelial cell vacuolization and desquamation was not observed, but occasional tubular atrophy and dilation were observed. Our study suggests that, some morphological alterations in the rat kidney, due to cigarette smoke may be prevented by resveratrol.

Effect of melatonin and vitamin C on expression of endothelial NOS in heart of chronic alcoholic rats

The aim of this study was to investigate the effects of melatonin and vitamin C on expression of endothelial nitric oxide synthase (NOS) in heart tissue of chronic alcoholic rats. Twenty-four adult male Wistar rats weighing 200-250 g were used in this study. Rats were divided into four groups. The first group served as control (n = 6). The second group was treated with ethanol (%7.2) for 28 days (n = 6), which was administered in artificial isocaloric diets. The third group was given ethanol and supplemented with 40 mg/kg vitamin C [intraperitoneally (i.p.)] (n = 6). The fourth group was given ethanol and supplemented with 4 mg/kg melatonin (i.p.) (n = 6). At the end of the experiment, rats were sacrificed and heart tissues were processed for immunohistochemistry analysis to endothelial NOS (eNOS). eNOS immunoreactivity showed heterogeneous distribution in control group. eNOS immunoreactivity was (+) in some myocytes and (++) in some others. Expression of eNOS in alcohol group was heterogeneous like control group but also stronger than that. Immunoreactivity was (+++) in myocytes near the epicardial zone and (++) in myocytes near the endocardium border. In melatonin and vitamin C-treated groups, eNOS immunoreactivity was diffuse and the intensity of reaction was (+++) in subepicardial region. However, eNOS immunoreactivity scores were weaker in these groups when compared with the alcohol group. Our results indicate that alleviation of oxidative stress by antioxidant therapy reduces reactive oxygen species-mediated nitric oxide inactivation.

Individual susceptibility to cadmium toxicity and metallothionein gene polymorphisms: with references to current status of occupational cadmium exposure

The incidence of serious poisoning caused by occupational cadmium exposure has declined over the past four decades due to improvements in the work environment. However, long-term low-level exposure to cadmium needs to be addressed. For workers in industries that handle cadmium, it is necessary to consider the daily cadmium intake from contaminated foods such as cereals and rice in addition to the occupational exposure, since workers might be exposed to higher levels of cadmium from a combination of these sources. Cadmium accumulates in the renal cortex by the long-term exposure along with increased concentrations of metallothionein, an important protein for protection from cadmium toxicity. However, some individuals have lower metallothionein levels despite increased cadmium accumulation in the kidneys. This article describes the strategy method for analyzing individual susceptibility to cadmium toxicity and genetic polymorphisms of metallothionein, with reference to the current status of occupational cadmium exposure.