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

The role of melatonin in preventing amiodarone-induced rat liver damage

Long-term exposure to amiodarone, an antiarrhythmic drug, can induce different organ damage, including liver. Cell damage included by amiodarone is a consequence of mitochondrial damage, reactive oxygen species production, and cell energy depletion leading to programmed cell death. In the present study, hepatoprotective potential of neurohormone melatonin (50 mg/kg/day) was evaluated in a chronic experimental model of liver damage induced by a 4-week application of amiodarone (70 mg/kg/day). The obtained results indicate that amiodarone induces an increase in xanthine oxidase activity, as well as the content of the lipid and protein oxidatively modified products and p53 levels. Microscopic analysis further corroborated the biochemical findings revealing hepatocyte degeneration, apoptosis, and occasional necrosis, with the activation of Kupffer cells. Coadministration of melatonin and amiodaron prevented an increase in certain damage associated parameters, due to its multiple targets. In conclusion, the application of melatonin together with amiodarone prevented an increase in tissue oxidative damage parameters and moderately prevented liver cell apoptosis, indicating that the damage of hepatocytes provoked by amiodarone supersedes the protective properties of melatonin in a given dose.

Marrubiin Inhibits Peritoneal Inflammatory Response Induced by Carrageenan Application in C57 Mice

Marrubiin is a diterpene with a long history of a wide range of biological activities. In this study, the anti-inflammatory effects of marrubiin were investigated using several in vitro and in vivo assays. Marrubiin inhibited carrageenan-induced peritoneal inflammation by preventing inflammatory cell infiltration and peritoneal mast cell degranulation. The anti-inflammatory activity was further demonstrated by monitoring a set of biochemical parameters, showing that the peritoneal fluid of animals treated with marrubiin had lower levels of proteins and lower myeloperoxidase activity compared with the fluid of animals that were not treated. Marrubiin exerted the most pronounced cytotoxic activity towards peripheral mononuclear cells, being the main contributors to peritoneal inflammation. Additionally, a moderate lipoxygenase inhibition activity of marrubiin was observed.

Melatonin as a Promising Anti-Inflammatory Agent in an In Vivo Animal Model of Sepsis-Induced Rat Liver Damage

Melatonin (MLT), earlier described as an effective anti-inflammatory agent, could be a beneficial adjunctive drug for sepsis treatment. This study aimed to determine the effects of MLT application in lipopolysaccharide (LPS)-induced sepsis in Wistar rats by determining the levels of liver tissue pro-inflammatory cytokines (TNF-α, IL-6) and NF-κB as well as hematological parameters indicating the state of sepsis. Additionally, an immunohistological analysis of CD14 molecule expression was conducted. Our research demonstrated that treatment with MLT prevented an LPS-induced increase in pro-inflammatory cytokines TNF-α and IL-6 and NF-κB levels, and in the neutrophil to lymphocyte ratio (NLR). On the other hand, MLT prevented a decrease in the blood lymphocyte number induced by LPS administration. Also, treatment with MLT decreased the liver tissue expression of the CD14 molecule observed after sepsis induction. In summary, in rats with LPS-induced sepsis, MLT was shown to be a significant anti-inflammatory agent with the potential to change the liver's immunological marker expression, thus ameliorating liver function.

Melatonin treatment prevents carbon-tetrachloride induced rat brain injury

Introduction

Herein the neuroprotective properties of melatonin, a highly effective antioxidant, administered in a single dose 50 mg/kg intraperitoneally, were investigated in the brain tissue of Wistar rats acutely exposed to the toxin carbon-tetrachloride (1 mL/kg, intraperitoneally).

Methods

To assess the degree of whole encephalic mass damage, biochemical parameters related to lipid and protein oxidation, antioxidant enzymes (catalase and superoxide dismutase), glutathione and inducible nitric oxide/arginase pathways were determined.

Results

The results showed that carbon-tetrachloride impaired the function of antioxidant enzymes (reduced catalase and superoxide dismutase activities) and reduced glutathione-metabolizing enzymes (reduced glutathione, glutathione S-transferase and peroxidase activity). Furthermore, carbon-tetrachloride increased lipid peroxidation and protein oxidative damage in the brain tissue, as well as myeloperoxidase and inducible nitric oxide synthase content/activities.

Conclusions

The application of a single dose of melatonin post intoxication has been able to reverse the disturbance in the function of antioxidant enzymes and alleviate the tissue damage caused by oxidative stress, indicating that melatonin could be a potential therapeutic agent in oxidative-damage related neurodegenerative disorders.

Melatonin modulates acute cardiac muscle damage induced by carbon tetrachloride - involvement of oxidative damage, glutathione, and arginine and nitric oxide metabolism

The present study was designed to evaluate the cardioprotective effects of melatonin (a single dose of 50 mg·kg-1), a naturally occurring polypharmacological molecule, in Wistar rats acutely exposed to carbon tetrachloride (CCl4). This was done for the first time by tracking different biochemical parameters that reflect rat heart antioxidative and oxidative capacities, nitric oxide and arginine metabolism, and the glutathione cycle. Additionally, the extrinsic apoptosis pathway related parameters were studied. Acute exposure to CCl4 led to an increase in the studied tissue oxidant parameters (hydrogen peroxide, malondialdehyde, and carbonylated protein content), as well as the activity alteration of antioxidant (catalase, superoxide dismutase, and peroxidase) and glutathione-metabolizing (glutathione peroxidase, S-transferase, and reductase) enzymes. Furthermore, CCl4 caused a disturbance in the tissue myeloperoxidase, nitric oxide, citrulline, arginase, and inducible nitric oxide synthase content and activities and in two apoptosis-related parameters, caspase-3 and FAS ligand. Melatonin as a post-treatment prevented the changes induced by CCl4 to a differing extent, and in some cases, it was so potent that it completely abolished any tissue disturbances. This study is a promising starting point for further research directed to the development of melatonin treatment in cardiac tissue associated diseases.

Hepatoprotection of Lycii Fructus Polysaccharide against Oxidative Stress in Hepatocytes and Larval Zebrafish

Scavenging of oxidative stress by antioxidants may provide a therapeutic strategy for nonalcoholic fatty liver disease (NAFLD). Increasing evidence is supporting the potential application of natural resourced polysaccharides as promising prevention or treatment strategies against NAFLD. In the current study, an acidic heteropolysaccharide, LFP-a1, was isolated and purified from Lycii fructus with successively hot water refluxing extraction, alcohol precipitation, protein removal, and DEAE-52 cellulose chromatographic separation. LFP-a1 was a complicated structured polysaccharide with an average MW of 4.74 × 104 Da and composed of 6 monosaccharides and 1 uronic acid. Preexposure of LFP-a1 could increase the cell viability and reverse the abnormal oxidative stress though inhibition of mitochondrial-mediated apoptotic pathway and correction of cell cycle progression against H₂O₂ hepatoxicity in NAFLD model L02 cells. Consistently, in vivo study in thioacetamide- (TAA-) induced NAFLD model zebrafish larvae showed LFP-a1 preserved the liver integrity and alleviated TAA-induced oxidative stress through downregulation of abnormal apoptosis. These observations indicated the hepatoprotective activity of LFP-a1, which may be applied for the prevention or treatment of NAFLD or other oxidative stress-related diseases.

Hepatoprotective Impact of Geraniol Against CCl₄-Induced Liver Fibrosis in Rats

BACKGROUND AND OBJECTIVE

Numerous experimental studies have shown various pharmacological activities including geraniol's cancer prevention agent and antioxidant capacity. The goal of this investigation is to mark the prospective defensive role of geraniol in rat's carbon tetrachloride (CCl4) instigated in liver fibrosis.

MATERIALS AND METHODS

Liver fibrosis was prompted by subcutaneous injections of CCl4, twice week by week and for about a month. Simultaneously, geraniol (200 mg kg-1) was orally regulated every day. Post-Hoc-Test were carried out where p<0.05 has been established as a significant value.

RESULTS

The biochemical results showed that geraniol reduced liver damage just as manifestations of liver fibrosis. The administration of geraniol diminished the CCl4-initiated the elevation in serum aminotransferase activities and alkaline phosphatase activity. Geraniol diminished the levels of TNF-α, NO and myeloperoxidase activity which were prompted by the CCl4 treatment. The rise of serum hyaluronidase activity and hepatic hydroxyproline content was also curtailed by geraniol treatment. Besides, geraniol fundamentally declined hepatic malondialdehyde (MDA) formation and increased reduced glutathione (GSH) in CCl4-treated rats. Geraniol has also increased the activity of hepatic antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione-S-transferase (GST) and glutathione peroxidase (GPx) in the rats treated with CCl4. Finally, the histological analysis of the liver bolstered the biochemical results.

CONCLUSION

Our study has demonstrated that geraniol has a hepatoprotective upshot on liver fibrosis caused by CCl4, supposedly due to its free radical scavenging, antioxidant and anti-inflammatory characteristics.

Caffeic acid phenethyl ester attenuates changes in pancreatic tissue damage biomarkers induced by cisplatin

Application of cisplatin (CP) for the treatment of different cancers is known to cause pancreatitis through an increase in reactive oxygen species production and promotion of inflammation. Caffeic acid phenethyl ester (CAPE), the main activity carrier of propolis extracts, was previously found to possess numerous beneficial properties. This study aims to determine for the first time the potential of CAPE in preventing CP-induced pancreatic tissue damage by studying the changes occurring on both biochemical and microscopic levels. The levels of serum α-amylase and a panel of pancreatic tissue biomarkers related to tissue injury (reduced glutathione, xanthine oxidase, malondialdehyde, and protein carbonylated concentration) and inflammation (myeloperoxidase, nitric oxide, and umor necrosis factor alpha) were studied in male Wistar rats treated with either CP alone or with CP and CAPE. Additionally, microscopic analysis of pancreatic tissue would be conducted as well. Application of CAPE together with CP statistically significantly prevented the disturbance in all here-studied pancreatic tissue damage and inflammation-related biomarkers. The changes in pancreas biochemical status was followed by morphological disturbance. The results of the present study suggest that CAPE could act as a protective agent in pancreatic damage that arises after CP application.

Melatonin and circadian rhythms in liver diseases: Functional roles and potential therapies

Circadian rhythms and clock gene expressions are regulated by the suprachiasmatic nucleus in the hypothalamus, and melatonin is produced in the pineal gland. Although the brain detects the light through retinas and regulates rhythms and melatonin secretion throughout the body, the liver has independent circadian rhythms and expressions as well as melatonin production. Previous studies indicate the association between circadian rhythms with various liver diseases, and disruption of rhythms or clock gene expression may promote liver steatosis, inflammation, or cancer development. It is well known that melatonin has strong antioxidant effects. Alcohol drinking or excess fatty acid accumulation produces reactive oxygen species and oxidative stress in the liver leading to liver injuries. Melatonin administration protects these oxidative stress-induced liver damage and improves liver conditions. Recent studies have demonstrated that melatonin administration is not limited to antioxidant effects and it has various other effects contributing to the management of liver conditions. Accumulating evidence suggests that restoring circadian rhythms or expressions as well as melatonin supplementation may be promising therapeutic strategies for liver diseases. This review summarizes recent findings for the functional roles and therapeutic potentials of circadian rhythms and melatonin in liver diseases.

Two different melatonin treatment regimens prevent an increase in kidney injury marker-1 induced by carbon tetrachloride in rat kidneys

Acute kidney injury is a frequent disorder that can be mimicked by the application of different nephrotoxic agents, including carbon tetrachloride (CCl₄), where kidney injury marker-1 (KIM-1) has been recognized as a highly specific marker. Melatonin is one of the most powerful natural antioxidants and has numerous beneficial properties. We evaluated the nephroprotective potential of 2 melatonin treatment regimens (pre- and post-intoxication) in a CCl₄-induced acute kidney injury model based on the standard serum parameters, kidney tissue antioxidative capacity, KIM-1 levels, and kidney tissue morphological changes. The two treatment regimens were found to preserve kidney function, as judged from the evaluated standard serum parameters. Only when administered after the intoxication, melatonin preserved total kidney antioxidant capacity; pre-treatment melatonin only preserved reduced glutathione levels. An increase in tissue KIM-1 level was found to be prevented by both treatment regimens, which correlated with the morphological changes seen in the kidney tissues of animals treated with melatonin and CCl₄. The findings of our study are in agreement with the known actions of melatonin in relieving kidney tissue oxidative burden, but also contribute to the understanding of its action by preventing an increase in KIM-1.

Exogenous putrescine affects polyamine and arginine metabolism in rat liver following bile ductus ligation

Rat bile duct ligation (BDL) represents a useful method that mimics obstructive extrahepatic cholestasis, which is known to be a frequent disorder in humans. Polyamines (putrescine, spermidine, and spermine) are one of the key molecules regulating cell proliferation and differentiation. This work aimed to evaluate the potential beneficial properties of putrescine in rat BDL model by studying several biochemical parameters reflecting liver function and polyamine metabolism. Rats that were subjected to BDL were injected with putrescine (150 mg/kg) for 9 days, while in parallel another group with BDL remained untreated. Two control groups were included as well, sham-opened and putrescine-treated group. The following plasma parameters: ALT, AST, γ-GT, ALP, bilirubin, bile acids, as well as liver malondialdehyde and polyamine concentration and the activity of enzymes involved in polyamine metabolism were studied. After BDL, significant alterations in plasma biochemical parameters occurred, where a 9-day putrescine treatment significantly alleviated liver function deterioration. Putrescine also increased liver polyamines’ concentrations and polyamine and diamine oxidase activities in rats submitted to BDL. Our results demonstrated, for the first time, that putrescine plays an important role in preserving liver tissue function in rats with experimentally induced cholestasis.

Effects of melatonin on oxidative stress parameters and pathohistological changes in rat skeletal muscle tissue following carbon tetrachloride application

Animal models demonstrating skeletal muscle (SM) disorders are rarely investigated, although these disorders accompany liver disorders and can occur during prolonged exercise/training. In cases of SM disorders exogenous antioxidants, such as melatonin, could help by generally improving tissues antioxidant capacities. We aimed to analyze the potential of melatonin in preventing biochemical and structural changes in rat biceps muscle (BM) occurring after an acute exposure to carbon tetrachloride (CCl₄). Biceps muscles obtained from male Wistar rats belonging to different experimental groups were biochemically (determination of tissue MDA, total antioxidant capacity, GSH, CAT, SOD and GPx activities) and pathologically analyzed. Also, serum levels of potassium, LHD and CK were analyzed in all experimental animals. The obtained results were statically compared with those from vehicle-treated control group. The applied melatonin prevented potassium and intracellular enzyme leakage (CK and LDH) that was induced by CCl₄, as well as an increase in tissue MDA. From a panel of determined oxidative stress parameters melatonin was able to statistically significantly prevent changes in total antioxidative capacity and in CAT, SOD and GPx activities induced by CCl₄. Microscopic analysis of BM from the animals exposed to CCl₄ revealed significant muscle fiber disorganization and massive inflammatory cell infiltration. All these changes were significantly ameliorated in the group that received melatonin prior to CCl₄. Changes in serum and tissue biochemical parameters accompanied the observed pathological changes, which demonstrated a significant influence of melatonin in preventing skeletal muscle damage induced by CCl₄.