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

Melatonin effects on oxidative stress and on TLR4/NF-kβ inflammatory pathway in the right ventricle of rats with pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is characterised by an increase in mean pulmonary arterial pressure and a compromised the right ventricle (RV), together with progression to heart failure and premature death. Studies have evaluated the role of melatonin as a promising therapeutic strategy for PAH. The objective of this study was to evaluate melatonin's effects on oxidative stress and on the TLR4/NF-kβ inflammatory pathway in the RV of rats with PAH. Male Wistar rats were divided into the following groups: control, monocrotaline (MCT), and monocrotaline plus melatonin groups. These two last groups received one intraperitoneal injection of MCT (60 mg/kg) on the first day of experimental protocol. The monocrotaline plus melatonin group received 10 mg/kg/day of melatonin by gavage for 21 days. Echocardiographic analysis was performed, and the RV was collected for morphometric analysis oxidative stress and molecular evaluations. The main findings of the present study were that melatonin administration attenuated the reduction in RV function that was induced by monocrotaline, as assessed by TAPSE. In addition, melatonin prevented RV diastolic area reduction caused by PAH. Furthermore, animals treated with melatonin did not show an increase in ROS levels or in NF-kβ expression. In addition, the monocrotaline plus melatonin group showed a reduction in TLR4 expression when compared with control and monocrotaline groups. To our knowledge, this is the first study demonstrating a positive effect of melatonin on the TLR4/NF-kβ pathway in the RV of rats with PAH. In this sense, this study makes it possible to think of melatonin as a possible ally in mitigating RV alterations caused by PAH.

Elucidating ascorbate and aldarate metabolism pathway characteristics via integration of untargeted metabolomics and transcriptomics of the kidney of high-fat diet-fed obese mice

Obesity is a major independent risk factor for chronic kidney disease and can activate renal oxidative stress injury. Ascorbate and aldarate metabolism is an important carbohydrate metabolic pathway that protects cells from oxidative damage. However the effect of oxidative stress on this pathway is still unclear. Therefore, the primary objective of this study was to investigate the ascorbate and aldarate metabolism pathway in the kidneys of high-fat diet-fed obese mice and determine the effects of oxidative stress. Male C57BL/6J mice were fed on a high-fat diet for 12 weeks to induce obesity. Subsequently, non-targeted metabolomics profiling was used to identify metabolites in the kidney tissues of the obese mice, followed by RNA sequencing using transcriptomic methods. The integrated analysis of metabolomics and transcriptomics revealed the alterations in the ascorbate and aldarate metabolic pathway in the kidneys of these high-fat diet-fed obese mice. The high-fat diet-induced obesity resulted in notable changes, including thinning of the glomerular basement membrane, alterations in podocyte morphology, and an increase in oxidative stress. Metabolomics analysis revealed 649 metabolites in the positive-ion mode, and 470 metabolites in the negative-ion mode. Additionally, 659 differentially expressed genes (DEGs) were identified in the obese mice, of which 34 were upregulated and 625 downregulated. Integrated metabolomics and transcriptomics analyses revealed two DEGs and 13 differential metabolites in the ascorbate and aldarate metabolic pathway. The expression levels of ugt1a9 and ugt2b1 were downregulated, and the ascorbate level in kidney tissue of obese mice was reduced. Thus, renal oxidative stress injury induced by high-fat diet affects metabolic regulation of ascorbate and aldarate metabolism in obese mice. Ascorbate emerged as a potential marker for predicting kidney damage due to high-fat diet-induced obesity.

Melatonin Prevents NaAsO2-Induced Developmental Cardiotoxicity in Zebrafish through Regulating Oxidative Stress and Apoptosis

Melatonin is an indoleamine hormone secreted by the pineal gland. It has antioxidation and anti-apoptosis effects and a clear protective effect against cardiovascular diseases. Our previous studies demonstrated that embryonic exposure to sodium arsenite (NaAsO₂) can lead to an abnormal cardiac development. The aim of this study was to determine whether melatonin could protect against NaAsO₂-induced generation of reactive oxygen species (ROS), oxidative stress, apoptosis, and abnormal cardiac development in a zebrafish (Danio rerio) model. We found that melatonin decreased NaAsO₂-induced zebrafish embryonic heart malformations and abnormal heart rates at a melatonin concentration as low as 10⁻⁹ mol/L. The NaAsO₂-induced oxidative stress was counteracted by melatonin supplementation. Melatonin blunted the NaAsO₂-induced overproduction of ROS, the upregulation of oxidative stress-related genes (sod2, cat, gpx, nrf2, ho-1), and the production of antioxidant enzymes (Total SOD, SOD1, SOD2, CAT). Melatonin attenuated the NaAsO₂-induced oxidative damage, DNA damage, and apoptosis, based on malonaldehyde and 8-OHdG levels and apoptosis-related gene expression (caspase-3, bax, bcl-2), respectively. Melatonin also maintained the control levels of heart development-related genes (nkx2.5, sox9b) affected by NaAsO₂. In conclusion, melatonin protected against NaAsO₂-induced heart malformations by inhibiting the oxidative stress and apoptosis in zebrafish.

Therapeutic effects of thymoquinone in doxorubicin-induced hepatotoxicity via oxidative stress, inflammation and apoptosis

Cancer is a lethal disease that is characterized by uncontrolled cell division and proliferation, and it results in death in many organisms. Doxorubicin (DOX) is a therapeutic agent used for treatment of many cancer types, but it induces serious hepatotoxicity. In this study, we aimed to determine possible hepato-therapeutic effects of thymoquinone (THQ) on DOX-induced hepatotoxicity in rats. Rats were divided into five groups (n = 8): Control, THQ (10 mg/kg/day/i.p for 14 days), Olive Oil (equal volume with THQ for 14 days), DOX (single dose, 15 mg/kg/i.p on 7th day) and DOX + THQ (10 mg/kg/day/i.p and DOX 15 mg/kg/i.p on 7th day). At the end of the experiment, liver tissues were extracted and evaluated histopathologically. eNOS, iNOS and Cas-3 immunostaining were performed to determine the expression levels. TUNEL method was used to determine apoptotic index. Furthermore, liver tissue total antioxidant status (TAS), total oxidant status (TOS), TNF-α and TGF-β levels were measured by ELISA assay. The DOX group showed histopathological deterioration compared to Control group. Moreover, apoptotic index, eNOS, iNOS and Cas-3 expressions increased in DOX group. While TAS level of the DOX group decreased, TOS level increased. TNF-α and TGF-β levels increased in DOX group. However, there was improvement in DOX + THQ group compared to DOX group. Moreover, apoptotic cell number, eNOS, iNOS and Cas-3 expressions decreased in DOX + THQ group compared to DOX group. We concluded that thymoquinone can be used as a phytotherapeutic for reducing DOX-induced liver damage.

Dietary Sources and Bioactivities of Melatonin

Insomnia is a serious worldwide health threat, affecting nearly one third of the general population. Melatonin has been reported to improve sleep efficiency and it was found that eating melatonin-rich foods could assist sleep. During the last decades, melatonin has been widely identified and qualified in various foods from fungi to animals and plants. Eggs and fish are higher melatonin-containing food groups in animal foods, whereas in plant foods, nuts are with the highest content of melatonin. Some kinds of mushrooms, cereals and germinated legumes or seeds are also good dietary sources of melatonin. It has been proved that the melatonin concentration in human serum could significantly increase after the consumption of melatonin containing food. Furthermore, studies show that melatonin exhibits many bioactivities, such as antioxidant activity, anti-inflammatory characteristics, boosting immunity, anticancer activity, cardiovascular protection, anti-diabetic, anti-obese, neuroprotective and anti-aging activity. This review summaries the dietary sources and bioactivities of melatonin, with special attention paid to the mechanisms of action.

Ameliorative effects of pentoxifylline on NOS induced by diabetes in rat kidney

OBJECTIVES

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease worldwide. The NO system has been implicated in the pathogenesis of DN. In this study, we aimed to evaluate the healing effect of pentoxifylline on NOS in STZ-induced diabetic rat's kidney.

MATERIAL AND METHODS

In this study, 50 Wistar albino male rats were used. The rats were divided into five groups; Group C control; Group D only diabetes; Group D + PI and D + PII diabetes + pentoxifylline; Group P only pentoxifylline. Group DPI rats received just pentoxifylline from the beginning of the experiments. However, Group DPII rats received saline in the first month and 50 mg/kg/day of pentoxifylline for the following month. At the end of two months, NOS expressions in kidney tissue were assessed using qRT-PCR and immunohistochemistry analysis.

RESULTS

At the end of the experiments, desquamation of the epithelial cells of the tubules, clear glycogen-filled distal tubules and increased number of apoptotic cells were seen in Group D. Diabetic rats' nNOS immunoreactivity had increased and eNOS and iNOS immunoreactivity had decreased; nNOS, iNOS and eNOS mRNA levels tended to decrease compared to the control group. PTX ameliorated eNOS, iNOS and nNOS protein levels and apoptotic cells, but did not affect mRNA levels.

CONCLUSION

In conclusion, PTX has a healing effect on this damage by affecting NOS expression.

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.

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.

Ascorbic acid mitigates the myocardial injury after cardiac arrest and electrical shock

PURPOSE

To examine the effects of ascorbic acid (AA) administrated during cardiopulmonary resuscitation (CPR) on the myocardial injury in a rat model of ventricular fibrillation (VF) and electrical shock (ES).

METHODS

VF was induced in male Wistar rats and left untreated for 5 min, followed by 1 min of CPR, and then one ES of 5 J. At the start of CPR, animals received either intravenous administration of AA (100 mg/kg) or Tempol (30 mg/kg), two antioxidants, or 0.9% saline (VF + ES group). After ES, animals were immediately killed. Myocardial lipoxidation was determined by malondialdehyde (MDA) assay. The histology and ultrastructural changes of myocardium were also evaluated. The mitochondrial permeability transition pore (mPTP) opening was measured based on the mitochondrial swelling rate. The complex activities and respiration of mitochondria were assessed, too.

RESULTS

Increased myocardial injury and mitochondrial damage in the VF + ES group were noted. AA and Tempol alleviated such damages. Both AA and Tempol improved accelerated mitochondrial swelling; decreased complex activities and respiratory dysfunction occurred in the VF + ES group. The animals receiving AA and Tempol during CPR had better successful resuscitation rates and 72-h survival than the VF + ES group.

CONCLUSIONS

Intravenous administration of AA and Tempol at the start of CPR may reduce lipid peroxidation and myocardial necrosis, diminish mitochondrial damage, facilitate resuscitation, and improve outcomes after VF + ES.