Melatonin prevents changes in microsomal membrane fluidity during induced lipid peroxidation

Melatonin Administration Enhances Testicular Volume, Testicular Blood Flow, Semen Parameters and Antioxidant Status during the Non-Breeding Season in Bafra Rams

Our objectives were to investigate the effects of exogenous melatonin on testicular volume (TV), testicular blood flow (TBF), and semen quality in Bafra rams during the non-breeding season. One group of rams (MEL, n = 5) received a 36 mg melatonin implant twice, with 30 days in between, while the other group (CON, n = 5) served as the control. TBF, TV, and semen quality parameters were determined at three-week intervals starting three weeks before until twelve weeks after the first melatonin implant. Testicular blood flow was determined in the supratesticular (STA) and marginal testicular artery (MA) using color Doppler ultrasound. Semen was collected and evaluated, and the total oxidative status (TOS) and total antioxidative status (TAS) was determined using an ELISA. The MEL group had increased (p < 0.05) TV between the sixth and twelfth week after the start of treatment. Overall, the MEL group had lower resistance and pulsatility indexes (p < 0.05) between the third and ninth week, although there was no difference (p > 0.05) between the two groups in most semen quality parameters. However, TAS concentrations increased (p < 0.05) in the MEL group compared with the CON. The results of this study show that exogenous melatonin in the non-breeding season significantly increased both TBF and TV in Bafra rams. Therefore, giving rams implants with 36 mg melatonin twice at least one month prior to the non-breeding season is expected to improve testicular size and function and reproductive capacity.

Does exposure to moonlight affect day/night changes in melatonin and metabolic parameters in Amazonian fish?

Lunar cycle modulates the rhythmic activity patterns of many animals, including fish. The effect of the moonlight cycle on daily melatonin and metabolic parameters was evaluated in matrinxã (Brycon amazonicus) subjected to external natural lighting. Eighty juvenile were distributed in 4 tanks of 1m3 (20 fish/tank) and divided into two groups. One group was exposed to the full moon and the other group to the new moon for 30 days, which corresponds to the duration of the lunar period. At the end of the lunar phase, 6 fish from each group were anesthetized to collect blood, tissue and eye samples at midday and midnight. The comparison between the light and dark periods revealed a significant increase in plasma and ocular melatonin in the last period. However, there was no significant difference for plasma melatonin between moons. Ocular melatonin presented higher concentrations during the new moon. Glucose, total proteins, cortisol, liver glutathione and gill lipid peroxidation were higher in the full moon compared to in the new moon. Plasma triglyceride was higher during the night for the full moon, and the opposite was found for the new moon. Total cholesterol values were higher at night regardless the moon phase. Glutathione in the gills and lipid peroxidation in the liver showed no significant differences. These results highlight the importance of considering both the day and lunar cycles for melatonin and metabolic parameters in species of commercial interest and susceptible to stressful situations in rearing conditions.

Cardioprotective effect of Justicia gendarussa on doxorubicin induced toxicity in mice

Justicia gendarussa Burm.f, belonging to the family Acanthaceae, is widely used for various ailments traditionally. Antioxidant, anti-arthritic, anti-inflammatory, analgesic, anticancerous, properties of the plant have been widely reported. The present study analyzed the cardioprotective effect of J. gendarussa on doxorubicin (DOX) induced toxicity in mice. Ethanolic extract of J. gendarussa was administered orally for 7 consecutive days. The alterations in oxido-reduction status, biochemical and histopathological parameters were analyzed in heart tissue. DOX increased superoxide dismutase (SOD) and catalase activities to 3.4 ± 0.5 and 3.68 ± 1 from their normal values 2.43 ± 0.8 and 2.72 ± 0.88, respectively. The increased activities of both the enzymes were found reduced to 3.12 ± 0.24 and 3.41 ± 0.65 by the treatment of the extract. Similarly, DOX elevated glutathione peroxidase (GPx) activity to 44.6 ± 3.71 from the normal level 32.33 ± 3.41. DOX decreased the glutathione (GSH) level to 15.66 ± 2.51 from the normal values 31.66 ± 4.05. Upon treatment, GPx activity and GHS level found restored. The increased lipid peroxidation 2.53 ± 0.25 of DOX was also decreased to 2.0 ± 0.34 by the extract. Histopathology observations substantiate the protective effect of J. gendarussa extract. In conclusion, DOX-induced disturbance of oxido-reduction status and histopathology of heart attenuated closer to the normal indicating the protective effect of J. gendarussa against DOX-induced toxicity in cardiomyocytes.

Insight into the molecular mechanism of phosphine toxicity provided by functional analysis of cytochrome b5 fatty acid desaturase and dihydrolipoamide dehydrogenase in the red flour beetle, Tribolium castaneum

Phosphine is the dominant chemical used in postharvest pest control. Widespread and highly frequent use of phosphine has been selected for pest insects, including Tribolium castaneum, which is highly resistant. Lipid peroxidation and reactive oxygen species (ROS) are two major factors determining phosphine toxicity; however, the mechanisms of production of these two factors in phosphine toxicity are still unknown. Here, we first determined the time course of phosphine-induced lipid peroxidation and ROS production in T. castaneum. Our results showed that lipid peroxidation occurs before ROS in the process of phosphine toxicity, and fumigated beetles with higher resistance levels were associated with weaker activity on lipid peroxidation and ROS. A significant decline in lipid peroxidation was observed in fumigated individuals after knockdown of cytochrome b5 fatty acid desaturase (Cyt-b5-r) via RNA interference (RNAi), indicating that Cyt-b5-r is critical for triggering phosphine-induced lipid peroxidation. Moreover, significant decreases in both ROS and mortality were detected in fumigated T. castaneum adults fed melatonin for 7 days, an inhibitor of lipid peroxidation. Cyt-b5-r RNAi also inhibited ROS production and mortality in phosphine-treated beetles. Meanwhile, a significant decrease in ROS production (68.4%) was detected in dihydrolipoamide dehydrogenase (DLD) knockdown individuals with phenotypes susceptible to phosphine, suggesting that lipid peroxidation initiates ROS with the expression of DLD. However, a significant increase in ROS (122.1%) was detected in the DLD knockdown beetles with strongly resistant phenotypes, indicating that the DLD-involved pathway may not be the only mechanism of ROS generation in phosphine toxicity and the existence of a moonlighting role in downregulating ROS in strongly resistant T. castaneum.

Melatonin Preserves Fluidity in Cell and Mitochondrial Membranes against Hepatic Ischemia-Reperfusion

We evaluated the in vivo effects of melatonin treatment on oxidative damage in the liver in an experimental model of ischemia-reperfusion. A total of 37 male Sprague-Dawley rats were randomly divided into four groups: control, ischemia, ischemia + reperfusion, and ischemia + reperfusion + melatonin. Hepatic ischemia was maintained for 20 min, and the clamp was removed to initiate vascular reperfusion for 30 min. Melatonin (50 mg/kg body weight) was intraperitoneally administered. Fluidity was measured by polarization changes in 1-(4-trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatriene-p-toluene sulfonate). After 20 min of ischemia, no significant changes were observed in cell and mitochondrial membrane fluidity levels, lipid peroxidation, and protein carbonylation. However, after 30 min of reperfusion, membrane fluidity decreased compared to controls. Increases in lipid and protein oxidation were also seen in hepatic homogenates of animals exposed to reperfusion. Melatonin injected 30 min before ischemia and reperfusion fully prevented membrane rigidity and both lipid and protein oxidation. Livers from ischemia-reperfusion showed histopathological alterations and positive labeling with antibodies to oxidized lipids and proteins. Melatonin reduced the severity of these morphological changes and protected against in vivo ischemia-reperfusion-induced toxicity in the liver. Therefore, melatonin might be a candidate for co-treatment for patients with hepatic vascular occlusion followed by reperfusion.

Melatonin: Regulation of Viral Phase Separation and Epitranscriptomics in Post-Acute Sequelae of COVID-19

The relentless, protracted evolution of the SARS-CoV-2 virus imposes tremendous pressure on herd immunity and demands versatile adaptations by the human host genome to counter transcriptomic and epitranscriptomic alterations associated with a wide range of short- and long-term manifestations during acute infection and post-acute recovery, respectively. To promote viral replication during active infection and viral persistence, the SARS-CoV-2 envelope protein regulates host cell microenvironment including pH and ion concentrations to maintain a high oxidative environment that supports template switching, causing extensive mitochondrial damage and activation of pro-inflammatory cytokine signaling cascades. Oxidative stress and mitochondrial distress induce dynamic changes to both the host and viral RNA m6A methylome, and can trigger the derepression of long interspersed nuclear element 1 (LINE1), resulting in global hypomethylation, epigenetic changes, and genomic instability. The timely application of melatonin during early infection enhances host innate antiviral immune responses by preventing the formation of "viral factories" by nucleocapsid liquid-liquid phase separation that effectively blockades viral genome transcription and packaging, the disassembly of stress granules, and the sequestration of DEAD-box RNA helicases, including DDX3X, vital to immune signaling. Melatonin prevents membrane depolarization and protects cristae morphology to suppress glycolysis via antioxidant-dependent and -independent mechanisms. By restraining the derepression of LINE1 via multifaceted strategies, and maintaining the balance in m6A RNA modifications, melatonin could be the quintessential ancient molecule that significantly influences the outcome of the constant struggle between virus and host to gain transcriptomic and epitranscriptomic dominance over the host genome during acute infection and PASC.

Excess DHA Induces Liver Injury via Lipid Peroxidation and Gut Microbiota-Derived Lipopolysaccharide in Zebrafish

Being highly unsaturated, n-3 long-chain polyunsaturated fatty acids (LC-PUFAs) are prone to lipid peroxidation. In this study, zebrafish were fed with low-fat diet (LFD), high-fat diet (HFD), or 2% DHA-supplemented HFD (HFDHA2.0). To study the possible negative effects of the high level of dietary DHA, growth rates, blood chemistry, liver histology, hepatic oxidative stress, apoptosis, and inflammatory processes were assessed. The cell studies were used to quantify the effects of DHA and antioxidant on cellular lipid peroxidation and viability. The possible interaction between gut microbiota and zebrafish host was evaluated in vitro. HFDHA2.0 had no effect on hepatic lipid level but induced liver injury, oxidative stress, and hepatocellular apoptosis, including intrinsic and death receptor-induced apoptosis. Besides, the inclusion of 2% DHA in HFD increased the abundance of Proteobacteria in gut microbiota and serum endotoxin level. In the zebrafish liver cell model, DHA activated intrinsic apoptosis while the antioxidant 4-hydroxy-Tempo (tempo) inhibited the pro-apoptotic negative effects of DHA. The apoptosis induced by lipopolysaccharide (LPS) was unaffected by the addition of tempo. In conclusion, the excess DHA supplementation generates hepatocellular apoptosis-related injury to the liver. The processes might propagate along at least two routes, involving lipid peroxidation and gut microbiota-generated LPS.

The Protective Role of Melatonin in Sperm Cryopreservation of Farm Animals and Human: Lessons for Male Fish Cryopreservation

Simple Summary

In recent years, cryopreservation of fish sperm has been a rapidly evolving technique that contributes both to the improvement of genetic reproduction programs and the proper management of broodstock as well as to ensuring the viability of endangered species. However, this technique can cause significant damage to sperm, making the use of cryoprotectants and antioxidants in cryopreservation solutions imperative. The hormone melatonin has demonstrated positive effects on the cryopreservation of sperm in both farm animals and humans. Therefore, the plethora of research that has been conducted on animals and humans could be expanded to fish cryopreservation, making melatonin potentially a very promising alternative cryoprotectant.

Abstract

Cryopreservation is a technique that offers various advantages, especially in fish, among others, that makes the reproduction of species easier through a constant supply of sperm, synchronization of the gamete availability of both sexes, storage of semen for genetic improvement programs, reduction in the cost by eliminating the need to maintain male broodstock, and conserving the gametes of endangered species. However, freezing and warming procedures for cryopreservation lead to a reduction in the quality and viability of cryopreserved sperm because of oxidative stress. For this reason, the enrichment of extender media with antioxidants is a common method of cryopreservation of the semen of several fish species. Recently, many studies have been published for the protective role of antioxidants and especially of melatonin on male fertility preservation both in farm animals and humans, demonstrating the beneficial effects of melatonin as a sperm cryoprotectant. On the other hand, very few studies were conducted using melatonin as an antioxidant in different male fish species for semen cryopreservation. We conclude that the use of moderate concentrations of melatonin are beneficial to semen preservation, and the mechanisms through which melatonin acts positively on spermatozoa need to be further investigated to establish improvement protocols for cryopreservation in fish species.

Molecular insight on the formation structure and dynamics of melatonin in an aqueous solution and at the Water-Air interface: A molecular dynamics study

Melatonin is a natural hormone that has been shown highly antioxidant effects. Consequently, it has been extensively studied for its therapeutic potential in several diseases such as insomnia, cardiovascular, Alzheimer, and certain types of cancers. Recently, it has been used to adjuvant treatment for COVID-19 patients. It is well-known that melatonin is highly hydrophobic, resulting in lower solubility. However, the molecular structure and dynamic behavior of the formation of melatonin in an aqueous solution and at the water-air interface have not yet been clearly explained. This information is necessary for the melatonin formulation in drug delivery systems. The present work focuses on the molecular structure and dynamics of melatonin molecules in the aqueous solution and at the water-air interface based on using a molecular dynamics simulation study. The results showed that most melatonin molecules were aggregated in an aqueous solution while they were formed a self-assembled monolayer with the ordered structure at the water-air interface. The strong interaction of melatonin depends on their functional group which showed a similar trend for both systems and was sequenced as follows: carbonyl O > indole NH > amide NH > methoxy OA, respectively. However, the carbonyl O and the indole NH groups exhibit strong interactions with water molecules at the interface. Consequently, the two preferred orientations of the melatonin head group can be observed at the water-air interface (i.e., one is to turn the head group to the water surface with the tilted angle of ~40°-60° and the second one is to turn the head group away from the water surface with the tilted angle of ~130°). The longer lifetime of hydrogen bonds formed between melatonin themselves in the bulk water reveals that the stability of melatonin aggregation in an aqueous solution is more stable. Therefore, melatonin has less soluble in an aqueous solution.

Melatonin improves heat tolerance in Actinidia deliciosa via carotenoid biosynthesis and heat shock proteins expression

The whole-genome molecular mechanisms of melatonin (MT)-mediated enhancement of thermotolerance in plants has rarely been studied. In this study, the genome-wide gene expression profiles of kiwifruit seedlings primed with MT and non-MT at 45°C were analyzed by RNA-Seq. A total of 3299 differentially expressed genes (DEGs) were screened between MT and non-MT treatment, in which carotenoid biosynthesis was one of the high-enrichment pathways revealed by Kyoto Encyclopedia of Genes and Genomes analysis. Further, qRT-PCR verified that MT significantly induced the upregulated expression of the carotenoid biosynthesis gene, which was consistent with the increase of carotenoid content. In addition, 10 heat shock proteins (HSPs) were identified to have a highly upregulated expression by MT. These findings provide a set of informative and fundamental data on the role of MT in heat resistance.

Attenuation of chronic arsenic neurotoxicity via melatonin in male offspring of maternal rats exposed to arsenic during conception: Involvement of oxidative DNA damage and inflammatory signaling cascades

Prenatal exposure to arsenic is demonstrated to elevate the risk of brain damage and neurological disorders in the fetus, mainly due to its ability for crossing through the placental barriers. Increase in oxidative stress, inflammation, and DNA damage is main mechanisms of arsenic-induced neurotoxicity. Therefore, this study aimed to evaluate the neuroprotective effects of melatonin, as a potent anti-oxidant and anti-inflammatory agent against arsenic toxicity in the brains of male offspring rats. Pregnant mother rats were randomly assigned into four groups including group I, as control, group II received 10 mg/kg melatonin, group III received arsenic at 50 mg/kg, and group IV received melatonin and arsenic. After a two-month period, oxidative stress, DNA damage, inflammation and apoptosis were assessed in the male offspring rats. Exposure to arsenic significantly increased the pro-inflammatory and oxidative factors resulting in DNA damage and apoptosis in the brain tissues of offspring rats in comparison to controls (p < 0.05). Exogenous administration of melatonin showed a significant increase in the tissue levels of acetylcholine esterase, decrease in the lactate dehydrogenase and myeloperoxidase, when compared to arsenic group (p < 0.05). Melatonin also overcame the arsenic-induced oxidative stress and suppressed inflammation, DNA damage and apoptosis. Our results suggested that melatonin may be a promising neuro-protective agent and momentous therapy for the treatment of arsenic-toxicity in clinical conditions.

Melatonin Alters Fluid Phase Coexistence in POPC/DPPC/Cholesterol Membranes

The structure and biophysical properties of lipid membranes are important for cellular functions in health and disease. In Alzheimer's disease, the neuronal membrane is a target for toxic amyloid-β (Aβ). Melatonin is an important pineal gland hormone that has been shown to protect against Aβ toxicity in cellular and animal studies, but the molecular mechanism of this protection is not fully understood. Melatonin is a small membrane-active molecule that has been shown to interact with model lipid membranes and alter the membrane biophysical properties, such as membrane molecular order and dynamics. This effect of melatonin has been previously studied in simple model bilayers with one or two lipid components. To make it more relevant to neuronal membranes, we used a more complex ternary lipid mixture as our membrane model. In this study, we used ²H-NMR to investigate the effect of melatonin on the phase behavior of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), and cholesterol lipid membranes. We used deuterium-labeled POPC-d₃₁ and DPPC-d₆₂,separately to probe the changes in hydrocarbon chain order as a function of temperature and melatonin concentration. We find that POPC/DPPC/cholesterol at molar proportions of 3:3:2 is close to liquid-disordered/liquid-ordered phase separation and that melatonin can induce phase separation in these ternary mixtures by preferentially incorporating into the disordered phase and increasing its level of disorder. At 5 mol% melatonin, we observed phase separation in samples with POPC-d₃₁, but not with DPPC-d₆₂, whereas at 10 mol% melatonin, phase separation was observed in both samples with either POPC-d₃₁ or DPPC-d₆₂. These results indicate that melatonin can have a strong effect on membrane structure and physical properties, which may provide some clues to understanding how melatonin protects against Aβ, and that choice of chain perdeuteration is an important consideration from a technical point of view.

Is Antioxidant Therapy a Useful Complementary Measure for Covid-19 Treatment? An Algorithm for Its Application

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) causes the corona virus disease-19 which is accompanied by severe pneumonia, pulmonary alveolar collapses and which stops oxygen exchange. Viral transmissibility and pathogenesis depend on recognition by a receptor in the host, protease cleavage of the host membrane and fusion. SARS-CoV-2 binds to the angiotensin converting enzyme 2 receptor. Here, we discuss the general characteristics of the virus, its mechanism of action and the way in which the mechanism correlates with the comorbidities that increase the death rate. We also discuss the currently proposed therapeutic measures and propose the use of antioxidant drugs to help patients infected with the SARS-CoV-2. Oxidizing agents come from phagocytic leukocytes such as neutrophils, monocytes, macrophages and eosinophils that invade tissue. Free radicals promote cytotoxicity thus injuring cells. They also trigger the mechanism of inflammation by mediating the activation of NFkB and inducing the transcription of cytokine production genes. Release of cytokines enhances the inflammatory response. Oxidative stress is elevated during critical illnesses and contributes to organ failure. In corona virus disease-19 there is an intense inflammatory response known as a cytokine storm that could be mediated by oxidative stress. Although antioxidant therapy has not been tested in corona virus disease-19, the consequences of antioxidant therapy in sepsis, acute respiratory distress syndrome and acute lung injury are known. It improves oxygenation rates, glutathione levels and strengthens the immune response. It reduces mechanical ventilation time, the length of stay in the intensive care unit, multiple organ dysfunctions and the length of stay in the hospital and mortality rates in acute lung injury/acute respiratory distress syndrome and could thus help patients with corona virus disease-19.

Oxidative stress and mitochondrial dysfunction in organophosphate pesticide-induced neurotoxicity and its amelioration: a review

Organophosphorus pesticides (OPs) are widely used for controlling pests worldwide. The inhibitory effects of these pesticides on acetylcholinesterase lead to neurotoxic damages. The oxidative stress is responsible for several neurological diseases, including Parkinson's disease, seizure, depression, and Alzheimer's disease. Strong evidence suggests that dysfunction of mitochondria and oxidative stress are involved in neurological diseases. OPs can disturb the function of mitochondria by inducing oxidative stress. In the present study, we tried to highlight the role of dysfunction of mitochondria and the induction of oxidative stress in the neurotoxicity induced by OPs. Additionally, the amelioration of OP-induced oxidative damage and mitochondrial dysfunctional through the chemical and natural antioxidants have been discussed.

Melatonin reduces aggressiveness and improves oxidative status of matrinxã (Brycon amazonicus) subjected to social challenge

Melatonin is a hormone that can modulate aggressive interactions in fish, stimulate antioxidant enzymes, and neutralize the biological damage caused by high free radical production. Fish, especially those kept in artificial environments, are subject to damage caused by free radicals resulting from stressful conditions, such as a social challenge. The matrinxã (Brycon amazonicus) arouses great commercial interest and has been widely used in farming systems. However, these animals have a high frequency of aggressive behavior and cannibalism, which is considered a limiting factor for the production system. Thus, we evaluated the influence of melatonin on aggressiveness and oxidative stress parameters in matrinxã juveniles, testing whether melatonin increases glutathione concentrations and reduces lipid peroxidation (thiobarbituric acid-reactive substances) during social challenge. For this, 24 fish were subjected to three concentrations of melatonin in water: control (0 μmol/L), low MEL (1 μmol/L), and high MEL (10 μmol/L), with eight replicates each. The fish were isolated for 96 h, subjected to the mirror test (social challenge), and then euthanized and dissected to remove the liver. Melatonin reduced total aggressive interactions in animals treated with melatonin (P = 0.036), increased glutathione concentrations (P = 0.002), and decreased levels of lipid peroxidation (P = 0.001). We concluded that melatonin reduces aggressiveness and acts as a potent antioxidant in matrinxã juveniles, contributing to the reduction in stress levels and thus improving the maintenance conditions of animals in production systems.

Effect of melatonin on bovine sperm characteristics and ultrastructure changes following cryopreservation

The production of reactive oxygen species (ROS) during cryopreservation of semen alters the sperm motion and mobility characteristics, resulting in poor or failure of conception rate after artificial insemination (AI). Melatonin an antioxidant is able to modulate the effect of ROS and prevents spermatozoa by reducing the oxidative stress during freezing process. Eight ejaculates from eight healthy HF bulls diluted with Tris egg yolk glycerol extender were divided into five equal aliquots. The Computer Assisted Semen Analyser (CASA) results showed no significant difference between the control-post- thaw samples and melatonin-treated samples; however, the velocity of spermatozoa with regard to the VAP, VSL showed highest increase in the 0.25 mM MLT-treated semen followed by 0.1 mM MLT treated semen except for VCL where velocity increased with increase in the concentration of melatonin. The vigour of spermatozoa regard to BCF, STR and LIN recorded highest increase in the 0.25 mM MLT treated semen followed by 0.1 mM MLT-treated semen except for the ALH where vigour increased with increase in the concentration of melatonin. The electron micrography images illustrated that the addition of 0.1 mM melatonin protected the plasma membrane and acrosome region and maintained the ultrastructure integrity of the cryopreserved spermatozoa when compared to control group, whereas the electron micrography of spermatozoa treated with 0.2 and 0.25 mM melatonin illustrated highest damage to the plasma and acrosome membrane. Thus concluding that inclusion of melatonin to sperm extender can improve the post-thaw quality of cryopreserved bull spermatozoa.

Melatonin ameliorates the drug induced nephrotoxicity: Molecular insights

BACKGROUND

Drug-induced nephrotoxicity is a frequent adverse event that can lead to acute or chronic kidney disease and increase the healthcare expenditure. It has high morbidity and mortality incidence in 40-70% of renal injuries and accounts for 66% cases of renal failure in elderly population.

OBJECTIVE

Amelioration of drug-induced nephrotoxicity has been long soughed to improve the effectiveness of therapeutic drugs. This study was conducted to review the melatonin potential to prevent the pathogenesis of nephrotoxicity induced by important nephrotoxic drugs.

METHODS

We analyzed the relevant studies indexed in Pubmed, Medline, Scielo and Web of science to explain the molecular improvements following melatonin co-administration with special attention to oxidative stress, inflammation and apoptosis as key players of drug-induced nephrotoxicity.

RESULTS

A robust consensus among researchers of these studies suggested that melatonin efficiently eradicate the chain reaction of free radical production and induced the endogenous antioxidant enzymes which attenuate the lipid peroxidation of cellular membranes and subcellular oxidative stress in drug-induced nephrotoxicity. This agreement was further supported by the melatonin role in disintegration of inflammatory process through inhibition of principle pro-inflammatory or apoptotic cytokines such as TNF-α and NF-κB. These studies highlighted that alleviation of drug-induced renal toxicity is a function of melatonin potential to down regulate the cellular inflammatory and oxidative injury process and to stimulate the cellular repair or defensive mechanisms.

CONCLUSION

The comprehensive nephroprotection and safer profile suggests the melatonin to be a useful adjunct to improve the safety of nephrotoxic drugs.

Anti-inflammatory and antioxidant properties of jervine, a sterodial alkaloid from rhizomes of Veratrum album

BACKGROUND

Veratrum, hellebore is an important plant species of the Liliaceae family and jervine is the characteristic steroidal alkaloid constituent of Veratrum album.

PURPOSE

In the current study, anti-inflammatory and antioxidant effects of jervine isolated from NH₄OH-benzene extract of V. album rhizomes were investigated on CAR induced paw edema in rats.

METHODS/STUDY DESIGN

In inflammatory study, 50, 100, 200 and 400  mg/kg doses of jervine, 25  mg/kg doses of DIC and IND were orally administered, and the volume of the foots were measured up to their knee arthrosis by plethismometer. After one hour of the oral administration of the all treatments, 0.1 ml of CAR solution (1%) was injected into the foot of the all rat groups and the volume of the foots were measured during 5 h after CAR injection. GPx, SOD, GR, MPO, CAT enzymes activities and GSH, LPO levels of the supernatants of paw homogenates and inflammation biomarkers such as TNF-α and IL-1β in the rats serums were also estimated.

RESULTS

According to the present results, jervine exerted 50.4-73.5% anti-inflammatory effects in carrageenan induced paw edema. Inflammation biomarkers such as TNF-α, IL-1β and MPO that increased by CAR injection were suppressed by the administrations of all doses of jervine, IND and DIC. In all paw tissues, LPO levels as indicator of oxidative tissue damage were found to be high in CAR-treated group and it was found to be decreased in all doses of jervine.

CONCLUSION

Jervine, DIC and IND reduced the negative effects of CAR due to increasing effects on the SOD, CAT, GSH, GPx and GR antioxidants.

Exogenous melatonin trigger biomass accumulation and production of stress enzymes during callogenesis in medicinally important Prunella vulgaris L. (Selfheal)

The objective of the current study was to monitor the variations caused by the application of exogenous melatonin on growth kinetics and production of stress enzymes in Prunella vulgaris. Leaf and petiole explants were used for callogenesis. These explants were inoculated on Murashige and Skoog media containing various concentrations of melatonin alone or in combination with 2.0 mg/l naphthalene acetic acid. Herein, a maximum of 3.18-g/100 ml fresh biomass accumulation was observed on day 35 during log phase of growth kinetics at 1.0 mg/l melatonin concentration from leaf explants. While 0.5 and 1.0 mg/l melatonin enhanced the biomass accumulation from petiole explants. Moreover, the synergistic combination of melatonin and naphthalene acetic acid also promoted growth from leaf and petiole explants. Leaf derived callus cultures treated with 1.0 mg/l melatonin induced the production of total protein content (90.47 μg BSAE/mg FW) and protease activity (4.77 U/g FW). While the calli obtained from petiole explants have shown highest content of total protein (160.8 μg BSAE/mg FW) and protease activity (5.35 U/g FW) on media containing 0.5 mg/l melatonin. Similarly, 0.5 mg/l melatonin enhanced superoxide dismutase (3.011 nM/min/mg FW) and peroxidase (1.73 nM/min/mg FW) enzymes from leaf derived callus cultures. The combination of 1.0 and 1.5 mg/l naphthalene acetic acid enhanced content of total protein and protease activity in leaf and petiole derived cultures. These results suggested that the application of melatonin play a positive role in biomass accumulation and production of stress enzymes in P. vulgaris.

Feeding mitochondria: Potential role of nutritional components to improve critical illness convalescence

Persistent physical impairment is frequently encountered after critical illness. Recent data point towards mitochondrial dysfunction as an important determinant of this phenomenon. This narrative review provides a comprehensive overview of the present knowledge of mitochondrial function during and after critical illness and the role and potential therapeutic applications of specific micronutrients to restore mitochondrial function. Increased lactate levels and decreased mitochondrial ATP-production are common findings during critical illness and considered to be associated with decreased activity of muscle mitochondrial complexes in the electron transfer system. Adequate nutrient levels are essential for mitochondrial function as several specific micronutrients play crucial roles in energy metabolism and ATP-production. We have addressed the role of B vitamins, ascorbic acid, α-tocopherol, selenium, zinc, coenzyme Q10, caffeine, melatonin, carnitine, nitrate, lipoic acid and taurine in mitochondrial function. B vitamins and lipoic acid are essential in the tricarboxylic acid cycle, while selenium, α-tocopherol, Coenzyme Q10, caffeine, and melatonin are suggested to boost the electron transfer system function. Carnitine is essential for fatty acid beta-oxidation. Selenium is involved in mitochondrial biogenesis. Notwithstanding the documented importance of several nutritional components for optimal mitochondrial function, at present, there are no studies providing directions for optimal requirements during or after critical illness although deficiencies of these specific micronutrients involved in mitochondrial metabolism are common. Considering the interplay between these specific micronutrients, future research should pay more attention to their combined supply to provide guidance for use in clinical practise. REVISION NUMBER: YCLNU-D-17-01092R2.

Melatonin Uptake by Cells: An Answer to Its Relationship with Glucose?

Melatonin, N-acetyl-5-methoxytryptamine, is an indole mainly synthesized from tryptophan in the pineal gland and secreted exclusively during the night in all the animals reported to date. While the pineal gland is the major source responsible for this night rise, it is not at all the exclusive production site and many other tissues and organs produce melatonin as well. Likewise, melatonin is not restricted to vertebrates, as its presence has been reported in almost all the phyla from protozoa to mammals. Melatonin displays a large set of functions including adaptation to light: dark cycles, free radical scavenging ability, antioxidant enzyme modulation, immunomodulatory actions or differentiation–proliferation regulatory effects, among others. However, in addition to those important functions, this evolutionary ‘ancient’ molecule still hides further tools with important cellular implications. The major goal of the present review is to discuss the data and experiments that have addressed the relationship between the indole and glucose. Classically, the pineal gland and a pinealectomy were associated with glucose homeostasis even before melatonin was chemically isolated. Numerous reports have provided the molecular components underlying the regulatory actions of melatonin on insulin secretion in pancreatic beta-cells, mainly involving membrane receptors MTNR1A/B, which would be partially responsible for the circadian rhythmicity of insulin in the organism. More recently, a new line of evidence has shown that glucose transporters GLUT/SLC2A are linked to melatonin uptake and its cellular internalization. Beside its binding to membrane receptors, melatonin transportation into the cytoplasm, required for its free radical scavenging abilities, still generates a great deal of debate. Thus, GLUT transporters might constitute at least one of the keys to explain the relationship between glucose and melatonin. These and other potential mechanisms responsible for such interaction are also discussed here.

Administration of slow release exogenous melatonin modulates oxidative stress profiles and in vitro fertilizing ability of the cryopreserved mithun (Bos frontalis) spermatozoa

Mithun (Bos frontalis) is a unique domestic free range bovine species of North Eastern hilly regions of India. The present study was designed to assess the seasonal effect of slow release exogenous melatonin (MT) implant on semen quality parameters (SQP) and in vitro zona binding ability (IVZ) of spermatozoa. The experimental animals were divided into Gr I: Control (n = 5) and Gr II: Treatment (n = 5; melatonin implant @ 18mg/50 kg bwt). A total of 20 semen samples/group in winter, spring, autumn and summer seasons (n = 160), twice per week were collected. Following cryopreservation, samples were evaluated for motility parameters (forward progressive, mobility & velocity by computer assisted sperm analyser (CASA), viability, acrosome integrity, plasma membrane and nuclear abnormality, functional status of mitochondria, enzymatic, antioxidant and oxidative profiles, and IVZ. The study revealed significant (p < 0.05) improvement in total motility, viability, acrosome-, plasma membrane-, and nuclear-integrity, and antioxidant profiles; with highest values in spring and lowest in summer season in the fresh semen in Gr II than the Control. A significant (p < 0.05) improvement in motility parameters, membrane potential of mitochondria, antioxidant profiles and reduction in sperm and nuclear abnormalities, leakage of intracellular enzymes and oxidative stress and IVZ index & binding percentage in post-thaw semen samples in melatonin supplemented than in un-supplemented control group was observed. It can be concluded from the study that slow-release melatonin supplementation can be effectively utilized to improve the antioxidant profiles and reduction of oxidative stress, with cascading beneficial effects on semen quality parameters and fertility status of the mithun bull.

Measuring urinary 8-hydroxy-2'-deoxyguanosine and malondialdehyde levels in women with overactive bladder

Purpose

In this study, we aimed to explain the role of oxidative stress in women with overactive bladder (OAB) by investigating the levels of 8-hydroxy-2′-deoxyguanosine (8-OHdG), a marker of oxidative DNA damage, and malondialdehyde (MDA), an indicator of lipid peroxidation.

Materials and Methods

A total of 90 women were included in the study: 45 female patients diagnosed with OAB at Hopa State Hospital Urology Polyclinic and 45 healthy women without any metabolic or neurologic disease. Levels of MDA and 8-OHdG were measured in 24-hour urine samples for all subjects.

Results

Urinary levels of MDA and 8-OHdG were significantly higher in the OAB group than in the control group (p<0.001). A significant positive correlation (p<0.001) was found between the measurements of 8-OHdG and MDA.

Conclusions

Oxidative stress may be important in the pathophysiology of OAB, because levels of 8-OHdG and MDA are increased. Increased levels of 8-OHdG may be due to damaged nuclear and mitochondrial DNA as a result of oxidative attacks caused by free radicals. Nevertheless, further randomized and prospective studies with larger patient populations are needed.

Pre- vs. post-treatment with melatonin in CCl4-induced liver damage: Oxidative stress inferred from biochemical and pathohistological studies

AIMS

The present study was designed to compare the ameliorating potential of pre- and post-treatments with melatonin, a potent natural antioxidant, in the carbon tetrachloride-induced rat liver damage model by tracking changes in enzymatic and non-enzymatic liver tissue defense parameters, as well as in the occurring pathohistological changes.

MAIN METHODS

Rats from two experimental groups were treated with melatonin before and after CCl₄ administration, while the controls, negative and positive, received vehicle/melatonin and CCl₄, respectively. Serum levels of transaminases, alkaline phosphates, γ-GT, bilirubin, and albumin, as well as a wide panel of oxidative stress-related parameters in liver tissue, were determined in all experimental animals. Liver tissue specimens were stained with hematoxylin and eosin and further evaluated for morphological changes.

KEY FINDINGS

Both pre- and post-treatment with melatonin prevented a CCl₄-induced increase in serum (ALT, AST, and γ-GT) and tissue (MDA and XO) liver damage markers and a decrease in the tissue total antioxidant capacity, in both enzymatic and non-enzymatic systems. The intensity of pathological changes, hepatocyte vacuolar degeneration, necrosis and inflammatory cell infiltration, was suppressed by the treatment with melatonin.

SIGNIFICANCE

In conclusion, melatonin, especially as a post-intoxication treatment, attenuated CCl₄-induced liver oxidative damage, increased liver antioxidant capacities and improved liver microscopic appearance. The results are of interest due to the great protective potential of melatonin that was even demonstrated to be stronger if applied after the tissue damage.

Effect of yeast (Xanthophyllomyces dendrorhous) and plant (Saint John's wort, lemon balm, and rosemary) extract based functional diets on antioxidant and immune status of Atlantic salmon (Salmo salar) subjected to crowding stress

Salmon farming may face stress due to the intensive culture conditions with negative impacts on overall performance. In this aspect, functional feed improves not only the basic nutritional requirements but also the health status and fish growth. However, to date no studies have been carried out to evaluate the effect of functional diets in salmon subjected to crowding stress. Thus, the aim of this study was to evaluate the effect of yeast extract (Xanthophyllomyces dendrorhous; diet A) and the combination of plant extracts (common Saint John's wort, lemon balm, and rosemary; diet B) on the antioxidant and immune status of Atlantic salmon grown under normal cultured conditions and then subjected to crowding stress. Fish were fed with functional diets during 30 days (12 kg/m³) and then subjected to crowding stress (20 kg/m³) for 10 days. The lipid peroxidation in gut showed that both diets induced a marked decrease on oxidative damage when fish were subjected to crowding stress. The protein carbonylation in muscle displayed at day 30 a marked decrease in both functional diets that was more marked on the stress condition. The expression of immune markers (IFNγ, CD4, IL-10, TGF-β, IgM_mb, IgM_sec, T-Bet, and GATA-3) indicated the upregulation of those associated to humoral-like response (CD4, IL-10, GATA-3) when fish were subjected to crowding stress. These results were confirmed with the expression of secreted IgM. Altogether, these functional diets improved the antioxidant status and increased the expression of genes related to Th2-like response suggesting a protective role on fish subjected to crowding stress.

Effects of Melatonin, Vitamin E and Octreotide on Lipid Peroxidation during Ischemia-Reperfusion in the Guinea Pig Retina

Purpose

The purpose of this study is to provide evidence that free radical damage is a component of retinal ischemia-reperfusion (I/R) injury, and to determine whether melatonin, vitamin E and octreotide can protect the retina from this injury.

Methods

The right eyes of 50 male guinea pigs weighing 500–600 g were used. The animals were randomly assigned to group 1 (control), group 2 (I/R), group 3 (melatonin + I/R), group 4 (vitamin E + I/R) and group 5 (octreotide + I/R). Groups 3, 4 and 5 received four subcutaneous injections with a 6-h interval for a total daily dose of 10 mg/kg melatonin, 150 mg/kg vitamin E and 22 μg/kg octreotide. The first dose of each substance was administered 5 minutes before retinal ischemia, which was induced for 1.5 hours, followed by reperfusion for 24 hours. All three substances were repeated for 6, 12 and 18 hours during reperfusion. The animals were killed at 24 hours of reperfusion. Retinas were isolated and processed for the quantification of malondialdehyde (MDA).

Results

The compounds had the following relationships: melatonin more than vitamin E more than octreotide in preventing retinal damage by ischemia-reperfusion. All three gave significant protection against the formation of MDA (10.4±2.3, 12.4±2.4, 13.9±1.5 nmol/100 mg tissue wet weight, respectively) compared to the control (3.7±1.3 nmol/100 mg tissue wet weight) and I/R groups (22.7±6.2 nmol/100 mg tissue wet weight).

Conclusions

This study demonstrates the inhibitory effect of melatonin, vitamin E and octreotide on MDA levels during retinal ischemia-reperfusion injury.

Melatonin transport into mitochondria

Melatonin is a well-known, nighttime-produced indole found in bacteria, eukaryotic unicellulars, animals or vascular plants. In vertebrates, melatonin is the major product of the pineal gland, which accounts for its increase in serum during the dark phase, but it is also produced by many other organs and cell types. Such a wide distribution is consistent with its multiple and well-described functions which include from the circadian regulation and adaptation to seasonal variations to immunomodulatory and oncostatic actions in different types of tumors. The discovery of its antioxidant properties in the early 1990s opened a new field of potential protective functions in multiple tissues. A special mention should be made regarding the nervous system, where the indole is considered a major neuroprotector. Furthermore, mitochondria appear as one of the most important targets for the indole's protective actions. Melatonin's mechanisms of action vary from the direct molecular interaction with free radicals (free radical scavenger) to the binding to membrane (MLT1A and MLT1B) or nuclear receptors (RZR/RORα). Receptor binding has been associated with some, but not all of the indole functions reported to date. Recently, two new mechanisms of cellular uptake involving the facilitative glucose transporters GLUT/SLC2A and the proton-driven oligopeptide transporter PEPT1/2 have been reported. Here we discuss the potential importance that these newly discovered transport systems could have in determining the actions of melatonin, particularly in the mitochondria. We also argue the relative importance of passive diffusion vs active transport in different parts of the cell.

Molecular mechanism of doxorubicin-induced cardiomyopathy - An update

Doxorubicin is utilized for anti-neoplastic treatment for several decades. The utility of this drug is limited due to its side effects. Generally, doxorubicin toxicity is originated from the myocardium and then other organs are also ruined. The mechanism of doxorubicin is intercalated with the DNA and inhibits topoisomerase 2. There are various signalling mechanisms involved in doxorubicin cardiotoxicity. First and foremost, the doxorubicin-induced cardiotoxicity is due to oxidative stress. Cardiac mitochondrial damage is supposed after few hours following the revelation of doxorubicin. This has led important new uses for the mechanism of doxorubicin-induced cardiotoxicity and novel avenues of investigation to determine better pharmacotherapies and interventions for the impediment of cardiotoxicity. The idea of this review is to bring up to date the recent findings of the mechanism of doxorubicin cardiomyopathies such as calcium dysregulation, endoplasmic reticulum stress, impairment of progenitor cells, activation of immune, ubiquitous system and some other parameters.

Analysis of Different Melatonin Secretion Patterns in Children With Sleep Disorders: Melatonin Secretion Patterns in Children

The objective of this study was to analyze circadian patterns of urinary 6-sulphatoxymelatonin (aMT6s) excretion in children with primary sleep disorders in comparison with healthy controls. A total of 124 control children and 124 patients (aged 4-14 years) diagnosed with diverse primary sleep disorders were recruited. aMT6s concentrations were measured in diurnal and nocturnal urine, as well as in 24-hour urine. aMT6s levels were significantly higher and showed significantly more evident circadian variations in the control group ( P < .001). Four different melatonin (aMT) production and excretion patterns were distinguished in the group with sleep disorders: (1) standard aMT production pattern, (2) low aMT production pattern, (3) aMT production pattern with absence of circadian variation, and (4) aMT hyperproduction pattern. This study highlights the importance of analyzing specific alterations of aMT secretion in each sleep disorder and provides evidences to explain why not all children with sleep disturbances do respond to aMT treatment.

Melatonin and N- Acetylcysteine as Remedies for Tramadol-Induced Hepatotoxicity in Albino Rats

Purpose: The therapeutic benefit derived from the clinical use of tramadol (TD) has been characterized by hepatotoxicity due to misuse and abuse. The implications of drug-induced hepatotoxicity include socio-economic burden which makes the search for remedy highly imperative. The present study investigated the protective effects of melatonin (MT) and n-acetylcysteine (NAC) on TD-induced hepatotoxicity in albino rats. Methods: Forty five adult rats used for this study were divided into nine groups of five rats each. The rats were pretreated with 10mg/kg/day of NAC, 10mg/kg/day of MT and combined doses of NAC and MT prior to the administration of 15 mg/kg/day of TD intraperitoneally for 7 days respectively. At the termination of drug administration, rats were weighed, sacrificed, and serum was extracted and evaluated for liver function parameters. The liver was harvested, weighed and evaluated for oxidative stress indices and liver enzymes. Results: Alanine aminotransferase, alkaline phosphatase, aspartate aminotransferase, total bilirubin, conjugated bilirubin, and malondialdehyde levels were significantly (P<0.05) increased in rats administered with TD when compared to control. Furthermore, glutathione, superoxide dismutase and catalase levels were decreased significantly (P<0.05) in rats administered with TD when compared to control. The Liver of TD-treated rats showed necrosis of hepatocytes. However, the observed biochemical and liver histological alterations in TD-treated rats were attenuated in NAC and MT pretreated rats. Interestingly, pretreatment with combined doses of NAC and MT produced significant (P<0.05) effects on all evaluated parameters in comparison to their individual doses. Conclusion: Based on the findings in this study, melatonin and n- acetylcysteine could be used clinically as remedies for tramadol associated hepatotoxity.

Mechanism of melatonin protection against copper-ascorbate-induced oxidative damage in vitro through isothermal titration calorimetry

AIMS

Involvement of oxidative stress in cardiovascular diseases is well established. Melatonin's role as an antioxidant and free radical scavenger via its receptor dependent and receptor independent pathways is well known. The aim of this study is to identify and elaborate upon a third mechanism by which melatonin is able to abrogate oxidative stress.

MAIN METHODS

Oxidative stress was induced in vitro, by copper (0.2mM)-ascorbate (1mM) in isolated goat heart mitochondria, cytosol and peroxisomes and they were co-incubated with graded doses of melatonin. Similar experiments in a cell-free chemical system involving two pure antioxidant enzymes, Cu-Zn superoxide dismutase and catalase was also carried out. Biochemical changes in activity of these antioxidant enzymes were analysed. Isothermal titration calorimetric studies with pure Cu-Zn superoxide dismutase and catalase were also carried out.

KEY FINDINGS

Incubation with copper-ascorbate led to alteration in activity of Cu-Zn superoxide dismutase and catalase which were found to be protected upon co-incubation with melatonin (80μM for catalase and 1μM for others). Results of isothermal titration calorimetric studies with pure Cu-Zn superoxide dismutase and catalase along with different combinations of copper chloride, ascorbic acid and melatonin suggest that when melatonin is present in the reaction medium along with copper-ascorbate, it restrains the copper-ascorbate molecules by binding with them physically along with scavenging the free radicals generated by them.

SIGNIFICANCE

The present study suggests that possibly, binding of melatonin with antioxidant enzymes masks the vulnerable sites of these antioxidant enzymes, thus preventing oxidative damage by copper-ascorbate molecules.

Effects of melatonin on seedling growth, mineral nutrition, and nitrogen metabolism in cucumber under nitrate stress

In China, excessive use of nitrogen fertilizers in glasshouses leads to nitrate accumulations in soil and plants, which then limits productivity. Melatonin, an evolutionarily highly conserved molecule, has a wide range of functions in plants. We analyzed the effects of melatonin pretreatment on the growth, mineral nutrition, and nitrogen metabolism in cucumber (Cucumis sativus L. "Jin You No. 1") when seedlings were exposed to nitrate stress. An application of 0.1 mmol/L melatonin significantly improved the growth of plants and reduced their susceptibility to damage due to high nitrate levels (0.6 mol/L) during the ensuing period of stress treatment. Although excess nitrate led to an increase in the concentrations of nitrogen, potassium, and calcium, as well as a decrease in levels of phosphorus and magnesium, exogenous melatonin generally had the opposite effect except for a further rise in calcium concentrations. Pretreatment also significantly reduced the accumulations of nitrate nitrogen and ammonium nitrogen and enhanced the activities of enzymes involved in nitrogen metabolism. Expression of Cs-NR and Cs-GOGAT, two genes that function in that metabolism, was greatly down-regulated when plants were exposed to 0.6 mol/L nitrate, but was up-regulated in plants that had received the 0.1 mmol/L melatonin pretreatment. Our results are the first evidence that melatonin has an important role in modulating the composition of mineral elements and nitrogen metabolism, thereby alleviating the inhibitory effect on growth normally associated with nitrate stress.

Phenolic Melatonin-Related Compounds: Their Role as Chemical Protectors against Oxidative Stress

There is currently no doubt about the serious threat that oxidative stress (OS) poses to human health. Therefore, a crucial strategy to maintain a good health status is to identify molecules capable of offering protection against OS through chemical routes. Based on the known efficiency of the phenolic and melatonin (MLT) families of compounds as antioxidants, it is logical to assume that phenolic MLT-related compounds should be (at least) equally efficient. Unfortunately, they have been less investigated than phenols, MLT and its non-phenolic metabolites in this context. The evidence reviewed here strongly suggests that MLT phenolic derivatives can act as both primary and secondary antioxidants, exerting their protection through diverse chemical routes. They all seem to be better free radical scavengers than MLT and Trolox, while some of them also surpass ascorbic acid and resveratrol. However, there are still many aspects that deserve further investigations for this kind of compounds.

The Role of Nutrition in Periodontal Health: An Update

Periodontal health is influenced by a number of factors such as oral hygiene, genetic and epigenetic factors, systemic health, and nutrition. Many studies have observed that a balanced diet has an essential role in maintaining periodontal health. Additionally, the influences of nutritional supplements and dietary components have been known to affect healing after periodontal surgery. Studies have attempted to find a correlation between tooth loss, periodontal health, and nutrition. Moreover, bone formation and periodontal regeneration are also affected by numerous vitamins, minerals, and trace elements. The aim of this review is to critically appraise the currently available data on diet and maintenance of periodontal health and periodontal healing. The effects of nutritional intervention studies to improve the quality of life and well-being of patients with periodontal disease have been discussed.

Melatonin role preventing steatohepatitis and improving liver transplantation results

Liver steatosis is a prevalent process that is induced due to alcoholic or non-alcoholic intake. During the course of these diseases, the generation of reactive oxygen species, followed by molecular damage to lipids, protein and DMA occurs generating organ cell death. Transplantation is the last-resort treatment for the end stage of both acute and chronic hepatic diseases, but its success depends on ability to control ischemia-reperfusion injury, preservation fluids used, and graft quality. Melatonin is a powerful endogenous antioxidant produced by the pineal gland and a variety of other because of its efficacy in organs; melatonin has been investigated to improve the outcome of organ transplantation by reducing ischemia-reperfusion injury and due to its synergic effect with organ preservation fluids. Moreover, this indolamine also prevent liver steatosis. That is important because this disease may evolve leading to an organ transplantation. This review summarizes the observations related to melatonin beneficial actions in organ transplantation and ischemic-reperfusion models.

Effects of phloretin on oxidative and inflammatory reaction in rat model of cecal ligation and puncture induced sepsis

BACKGROUND

Sepsis is a debilitating systemic disease and described as a severe and irregular systemic inflammatory reaction syndrome (SIRS) against infection. We employed CLP (Cecal Ligation and Puncture) model in rats to investigate anti-inflammatory and antioxidant effects of phloretin, as a natural antioxidant agent, and its protective effect on liver tissue damage caused by sepsis.

METHODS

Male Wistar albino rats were randomly divided into three groups: sham group, CLP induced sepsis group and phloretin treated CLP group. Sepsis was induced by CLP method. 50 mmol/kg Phloretin was administered intraperitoneally in two equal doses immediately after surgery.

RESULTS

It was observed that blood urea nitrogen (BUN) and tumor necrosis factor alpha (TNF-α) levels were dramatically increased in the CLP induced sepsis group (43.88 ± 1.905 mg/dl, 37.63 ± 1.92, respectively) when compared to the sham group. Moreover, tissue Glutathione (GSH) and liver nuclear factor ĸB (NF-ĸB p65) transcription factor values were higher in CLP induced sepsis group. This elevation was considerably reduced in the phloretin treated CLP group. No significant differences were observed in serum creatinine and creatinine phosphokinase levels.

CONCLUSIONS

The present study suggested that phloretin, as a natural protective agent, act against tissue damages introduced following the experimental sepsis induced model, likely caused by free oxygen radicals.

Drug-Induced Liver Toxicity and Prevention by Herbal Antioxidants: An Overview

The liver is the center for drug and xenobiotic metabolism, which is influenced most with medication/xenobiotic-mediated toxic activity. Drug-induced hepatotoxicity is common and its actual frequency is hard to determine due to underreporting, difficulties in detection or diagnosis, and incomplete observation of exposure. The death rate is high, up to about 10% for drug-induced liver damage. Endorsed medications represented >50% of instances of intense liver failure in a study from the Acute Liver Failure Study Group of the patients admitted in 17 US healing facilities. Albeit different studies are accessible uncovering the mechanistic aspects of medication prompted hepatotoxicity, we are in the dilemma about the virtual story. The expanding prevalence and effectiveness of Ayurveda and natural products in the treatment of various disorders led the investigators to look into their potential in countering drug-induced liver toxicity. Several natural products have been reported to date to mitigate the drug-induced toxicity. The dietary nature and less adverse reactions of the natural products provide them an extra edge over other candidates of supplementary medication. In this paper, we have discussed the mechanism involved in drug-induced liver toxicity and the potential of herbal antioxidants as supplementary medication.

Even a Chronic Mild Hyperglycemia Affects Membrane Fluidity and Lipoperoxidation in Placental Mitochondria in Wistar Rats

It is known the deleterious effects of diabetes on embryos, but the effects of diabetes on placenta and its mitochondria are still not well known. In this work we generated a mild hyperglycemia model in female wistar rats by intraperitoneal injection of streptozotocin in 48 hours-old rats. The sexual maturity onset of the female rats was delayed around 6–7 weeks and at 16 weeks-old they were mated, and sacrificed at day 19th of pregnancy. In placental total tissue and isolated mitochondria, the fatty acids composition was analyzed by gas chromatography, and lipoperoxidation was measured by thiobarbituric acid reactive substances. Membrane fluidity in mitochondria was measured with the excimer forming probe dipyrenylpropane and mitochondrial function was measured with a Clark-type electrode. The results show that even a chronic mild hyperglycemia increases lipoperoxidation and decreases mitochondrial function in placenta. Simultaneously, placental fatty acids metabolism in total tissue is modified but in a different way than in placental mitochondria. Whereas the chronic mild hyperglycemia induced a decrease in unsaturated to saturated fatty acids ratio (U/S) in placental total tissue, the ratio increased in placental mitochondria. The measurements of membrane fluidity showed that fluidity of placenta mitochondrial membranes increased with hyperglycemia, showing consistency with the fatty acids composition through the U/S index. The thermotropic characteristics of mitochondrial membranes were changed, showing lower transition temperature and activation energies. All of these data together demonstrate that even a chronic mild hyperglycemia during pregnancy of early reproductive Wistar rats, generates an increment of lipoperoxidation, an increase of placental mitochondrial membrane fluidity apparently derived from changes in fatty acids composition and consequently, mitochondrial malfunction.

Melatonin and Its Role in Lower Urinary Tract Function: An Article Review

This article reviewed the results of studies done on animals that assessed effects of melatonin on bladder function. Melatonin does not change strip relaxation on its own. However, pre-treatment with melatonin decreases contractile responses induced by phenylephrine, acetylcholine, bethanechol and KCl in a dose-dependent manner. The contractile responses induced by the direct calcium channel openers are significantly decreased by melatonin pre-treatment. It also binds to Ca(2+)-activated calmodulin, and prevents it from activating myosin light-chain kinase. It may have direct effects on ion channels which are responsible for regulating bladder contraction. Its other mode of action on bladder occurs via the brain GABAA receptor. Melatonin is an antioxidant. In bladder, treatment with melatonin prevents elevations in malondialdehyde levels, reverses changes in glutathione levels, and decreases myeloperoxidase levels compared with oxidative injury. It can normalize age induced bladder dysfunction through its antioxidant effects, inhibiting smooth muscle contractility directly and restoring impaired contractility via normalization of Ca(2+) handling and sensitizations pathways. It attenuates the severity of cystitis and inflammation. Mast cell proliferation and activation are increased in cystitis, but decrease by melatonin treatment. Also, there is a decrease in expression levels of pro-inflammatory cytokines after melatonin treatment.

The organization of melatonin in lipid membranes

Melatonin is a hormone that has been shown to have protective effects in several diseases that are associated with cholesterol dysregulation, including cardiovascular disease, Alzheimer's disease, and certain types of cancers. We studied the interaction of melatonin with model membranes made of dimyristoylphosphatidylcholine (DMPC) at melatonin concentrations ranging from 0.5mol% to 30mol%. From 2-dimensional X-ray diffraction measurements, we find that melatonin induces a re-ordering of the lipid membrane that is strongly dependent on the melatonin concentration. At low melatonin concentrations, we observe the presence of melatonin-enriched patches in the membrane, which are significantly thinner than the lipid bilayer. The melatonin molecules were found to align parallel to the lipid tails in these patches. At high melatonin concentrations of 30mol%, we observe a highly ordered melatonin structure that is uniform throughout the membrane, where the melatonin molecules align parallel to the bilayers and one melatonin molecule associates with 2 lipid molecules. Understanding the organization and interactions of melatonin in membranes, and how these are dependent on the concentration, may shed light into its anti-amyloidogenic, antioxidative and photoprotective properties and help develop a structural basis for these properties.

Manganese superoxide dismutase and oxidative stress modulation

Oxidative stress is characterized by imbalanced reactive oxygen species (ROS) production and antioxidant defenses. Two main antioxidant systems exist. The nonenzymatic system relies on molecules to directly quench ROS and the enzymatic system is composed of specific enzymes that detoxify ROS. Among the latter, the superoxide dismutase (SOD) family is important in oxidative stress modulation. Of these, manganese-dependent SOD (MnSOD) plays a major role due to its mitochondrial location, i.e., the main site of superoxide (O(2)(·-)) production. As such, extensive research has focused on its capacity to modulate oxidative stress. Early data demonstrated the relevance of MnSOD as an O(2)(·-) scavenger. More recent research has, however, identified a prominent role for MnSOD in carcinogenesis. In addition, SOD downregulation appears associated with health risk in heart and brain. A single nucleotide polymorphism which alters the mitochondria signaling sequence for the cytosolic MnSOD form has been identified. Transport into the mitochondria was differentially affected by allelic presence and a new chapter in MnSOD research thus begun. As a result, an ever-increasing number of diseases appear associated with this allelic variation including metabolic and cardiovascular disease. Although diet and exercise upregulate MnSOD, the relationship between environmental and genetic factors remains unclear.

The effect of exogenous oxytocin on streptozotocin (STZ)-induced diabetic adult rat testes

Oxytocin (OXY) plays a crucial role in reproduction. The aim of this study is to investigate the therapeutic and protective effects of oxytocin treatment on streptozotocin (STZ) induced diabetes in testicular tissue. The rats were randomly divided into four experimental groups: (I) Control Group, (II) STZ induced Diabetic Group (STZ Group), (III) STZ induced Diabetic Group with Pre-Oxytocin treatment (Pre-OXY Group) and (IV) STZ induced Diabetic Group with Post-Oxytocin treatment (Post-OXY Group); each group contains six animals. The rats whose blood glucose levels were more than 200mg/dl were included to the experiment. At the end of the 4th week, testes tissue samples were taken to be processed for light microscopy and transmission electron microscopy. Malondialdehyde (MDA), Glutathione (GSH) and Advanced Oxidation Protein Products (AOPP) levels were determined biochemically in blood samples. Testicular tissue samples stained with Hematoxylin and Eosin (H&E) and Periodic acid-Schiff (PAS) reaction were evaluated under light microscope. The histopathological damage score of testicular tissue, which was significantly increased in STZ group, was decreased by oxytocin treatment. According to biochemical data, MDA and AOPP levels have been increased in the blood of STZ Group compared to the Control Group whereas they decreased significantly in Oxytocin-treated Groups compared to STZ Group. GSH levels were significantly decreased in the blood of STZ Group and increased in the blood of Oxytocin-treated Groups compared to STZ Group. In conclusion, oxytocin has a potential protective effect on the testes tissue of STZ-induced diabetic rats.