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.

Design and development of novel therapeutics for brucellosis treatment based on carbonic anhydrase inhibition.

Carbonic anhydrase is a metalloprotein, an enzyme with strong inhibition in antibacterial treatment. This study presents QSAR modeling for a series of 41 chemical compounds, 40 sulfonamides and one sulfamate, including 13 clinically tested drugs as carbonic anhydrase inhibitors based on the Monte Carlo optimization with molecular descriptors based on the SMILES notation and local invariants of the molecular graph, and field 3D based methods. Conformation independent QSAR models were developed for three random splits and a 3D QSAR model for one random split into the training and test sets. The statistical quality of the developed models, including robustness and predictability, was tested using various statistical approaches and the results that were obtained were very good. An excellent correlation between the results from the conformation independent and the 3D QSAR model was obtained. A novel statistical metric known as the index of ideality of correlation was used for the final assessment of the model, and the obtained results were good. Molecular fragments responsible for the increases and decreases of a studied activity were defined and further used for the computer-aided design of new compounds as potential carbonic anhydrase inhibitors. Molecular docking was applied for the final assessment of the developed QSAR model and designed inhibitors, and an excellent correlation between the results from QSAR modeling and molecular docking studies was obtained.Communicated by Ramaswamy H. Sarma.

Anthocyanins Protect Hepatocytes against CCl4-Induced Acute Liver Injury in Rats by Inhibiting Pro-inflammatory mediators, Polyamine Catabolism, Lipocalin-2, and Excessive Proliferation of Kupffer Cells.

: This study examined the hepatoprotective and anti-inflammatory effects of anthocyanins from Vaccinim myrtillus (bilberry) fruit extract on the acute liver failure caused by carbon tetrachloride-CCl4 (3 mL/kg, i.p.). The preventive treatment of the bilberry extract (200 mg anthocyanins/kg, orally, 7 days) prior to the exposure to the CCl4 resulted in an evident decrease in markers of liver damage (glutamate dehydrogenase, sorbitol dehydrogenase, malate dehydrogenase), and reduced pro-oxidative (conjugated dienes, lipid hydroperoxide, thiobarbituric acid reactive substances, advanced oxidation protein products, NADPH oxidase, hydrogen peroxide, oxidized glutathione), and pro-inflammatory markers (tumor necrosis factor-alpha, interleukin-6, nitrite, myeloperoxidase, inducible nitric oxide synthase, cyclooxygenase-2, CD68, lipocalin-2), and also caused a significant decrease in the dissipation of the liver antioxidative defence capacities (reduced glutathione, glutathione S-transferase, and quinone reductase) in comparison to the results detected in the animals treated with CCl4 exclusively. The administration of the anthocyanins prevented the arginine metabolism's diversion towards the citrulline, decreased the catabolism of polyamines (the activity of putrescine oxidase and spermine oxidase), and significantly reduced the excessive activation and hyperplasia of the Kupffer cells. There was also an absence of necrosis, in regard to the toxic effect of CCl4 alone. The hepatoprotective mechanisms of bilberry extract are based on the inhibition of pro-oxidative mediators, strong anti-inflammatory properties, inducing of hepatic phase II antioxidant enzymes (glutathione S-transferase, quinone reductase) and reduced glutathione, hypoplasia of Kupffer cells, and a decrease in the catabolism of polyamines.

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.

In silico studies and the design of novel agents for the treatment of systemic tuberculosis.

Tuberculosis (TB) is an ancient infectious disease, which re-emerged with the appearance of multidrug-resistant strains and acquired immune deficiency syndrome. Enoyl-acyl-carrier protein reductase (InhA) has emerged as a promising target for the development of anti-tuberculosis therapeutics. This study aims to develop quantitative structure-activity relationship (QSAR) models for a series of arylcarboxamides as InhA inhibitors. The QSAR models were calculated on the basis of optimal molecular descriptors based on the simplified molecular-input line-entry system (SMILES) notation with the Monte Carlo method as a model developer. The molecular docking study was used for the final assessment of the developed QSAR model and designed novel inhibitors. Methods used for the validation indicated that the predictability of the developed model was good. Structural indicators defined as molecular fragments responsible for increases and decreases of the studied activity were defined. The computer-aided design of new compounds as potential InhA inhibitors was presented. The Monte Carlo optimization was capable of being an efficient in silico tool for developing a model of good statistical quality. The predictive potential of the applied approach was tested and the robustness of the model was proven using different methods. The results obtained from molecular docking studies were in excellent correlation with the results from QSAR studies. This study can be useful in the search for novel anti-tuberculosis therapeutics based on InhA inhibition. Communicated by Ramaswamy H. Sarma.

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.

Oxidative stress, NOx/l-arginine ratio and glutathione/glutathione S-transferase ratio as predictors of 'sterile inflammation' in patients with alcoholic cirrhosis and hepatorenal syndrome type II.

Continuous intake of alcohol leads to liver cirrhosis because of imbalance of oxidative stress/antioxidative defense and chronic 'sterile inflammation'. Hepatorenal syndrome (HRS) is the most severe complication of liver cirrhosis. The aim of our study was to assess: (1) the oxidative stress/antioxidative defense markers such as malondialdehyde (MDA), oxidative glutathione (GSH) and glutathione S-transferase (GST), (2) inflammation [C-reactive protein (CRP)], and (3) nitrate/nitrite levels (NOx) and its substrate L-arginine level. The study enrolled three groups: a group with cirrhosis and HRS (48 patients), a group with cirrhosis without HRS (32 patients), and a control group (40 healthy blood donors). All the patients with cirrhosis and HRS had type II HRS. MDA concentration was significantly higher in the groups with cirrhosis with and without HRS. Significant positive correlation was documented between the MDA level and de Ritis coefficient (AST/ALT), a marker of liver damage severity; between MDA and inflammation (CRP); between MDA and NOx concentration in the groups with cirrhosis with and without HRS. The correlation between MDA and creatinine level was significant in the group with HRS. The levels of GSH and GST were significantly lower in the groups with cirrhosis with and without HRS. The results of the study revealed that an increase in MDA and NOx concentration, along with decreased values of antioxidative defense and L-arginine, may indicate that liver damage can have an influence on progression to renal failure.