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The COVID-19 pandemic emerged in 2019, bringing with it the need for greater stores of effective antiviral drugs. This paper deals with the conformation-independent, QSAR model, developed by employing the Monte Carlo optimization method, as well as molecular graphs and the SMILES notation-based descriptors for the purpose of modeling the SARS-CoV-3CLpro enzyme inhibition. The main purpose was developing a reproducible model involving easy interpretation, utilized for a quick prediction of the inhibitory activity of SAR-CoV-3CLpro. The following statistical parameters were present in the best-developed QSAR model: (training set)The online version contains supplementary material available at 10.1007/s11696-022-02170-8.

Diabetes and obesity are very common associated metabolic disorders that are linked to chronic inflammation. The development of insulin resistance is driven by multiple factors including an increase in levels of pro-inflammatory cytokines such as tumor necrosis factoralpha (TNF-a). This study aimed to explore the links between TNF-a -mediated inflammation, insulin sensitivity, and body weight gain in the rat model of type 2 diabetes mellitus (T2DM). The experiment was performed on 10 weeks old Wistar rats randomized into 2 groups. T2DM was induced by intraperitoneal injection of streptozotocin, administered 15 minutes after an intraperitoneal injection of nicotinamide. After 6 weeks, the animals were euthanized. Insulin and TNF-a were determined by using an enzyme-linked immunosorbent assay kit. Insulin sensitivity indices were calculated. The concentration of TNF-a was significantly higher in animals with T2DM when compared to controls (p < 0.001). Quantitative Insulin Sensitivity Check Index (QIUCKI) had significantly lower values in animals with T2DM when compared to controls (p < 0.001), whereas values calculated for homeostatic model assessment of insulin resistance (HOMA-IR) were significantly higher (p < 0.001). TNF-a correlated positively with HOMA-IR (r = 0.562, p < 0.01) and negatively with QIUCKI (r =-0.332, p < 0.05). Additionally, TNF-a correlated positively with specific rate of the body weight gain (r = 0.667, p < 0.01) in the observed period. The results suggest that an increase in circulating TNF-a concentration might be associated with an increase in body weight gain and reduced insulin sensitivity in rats with T2DM.

The aim of this study was to analyze injuries to the primary teeth and adjacent soft tissues in relation to the gender and age of injured children, type of injury, place, and mechanism of injury. The study enrolled 115 children (71 boys and 44 girls) managed at the Dentistry Clinic, Faculty of Medicine, University of Niš, in the period 2009-2019. The information about the type of injury, place, and mechanism of injury were obtained from the medical records of the patients aged 1-5 years. Our analysis established that there were statistically significantly (p < 0.05) more injured boys (61.74%) than girls (38.26%). Subluxation was the most common primary teeth injury, present in 60 (52.17%) children and was statistically significantly more prevalent compared to other injuries (p < 0.001). Of the injuries to the adjacent soft tissues, laceration was statistically significantly more common than other soft tissue injuries (p < 0.001). Children were most commonly injured at their homes (52.17%), and rarely in their day nurseries (3.48%). Falling was the most common cause of injuries (63.48%). Based on the obtained results, a conclusion may be drawn that boys were more commonly injured compared to girls, and that falls were the most common cause. Injuries usually occurred at the age of about 2 years. Subluxation was the most common injury, and children usually got injured at their own home.

Both oxidative and psychological (mental) stress are the likely culprits for several acute and chronic health disturbances, and adequate tests mimicking that are needed. Herein, in controlled laboratory surroundings, a PEBL (Psychology Experiment Building Language) test battery was used to evoke stress-related biological responses followed by tracking changes in saliva parameters. The study objectives were to determine the impact of psychological stress on selected salivatory parameters and to assess the correlation between the determined oxidative and stress parameters. The study was conducted on 36 healthy young subjects, mainly females ( n = 24 ). Before and following the completion of a battery of four PEBL tests, subjects’ saliva samples were collected. Stress-evoking changes in total antioxidant capacity and nitrite/nitrate levels, as oxidative stress parameters, and cortisol and immunoglobulin A (IgA), as parameters of psychological stress, were established and mutually correlated by comparing the values of the evaluated parameters pre- and post-PEBL test. The results showed that there is no change in the total salivary antioxidant capacity ( p > 0.05 ); however, there was a significant increase in nitrites/nitrates levels after the PEBL test ( p = 0.007 ). On the other hand, the determined cortisol levels after the test battery were found to be statistically significantly increased ( p = 0.025 ) when compared to the values obtained before the test, while the levels of IgA were found to be statistically significantly decreased ( p < 0.001 ). The only statistically significant correlation between the changes in the studied parameters was found to be the one between cortisol and IgA levels (Spearman’s Rö = -0.4). These results suggest that the short-term stress induced by the PEBL test does evoke changes in the salivary mental stress-related parameters (an increase in cortisol and nitrite/nitrate levels, and a decrease in IgA), but not in the total antioxidant capacity. They also indicate that the constructed PEBL four-test battery might represent an adequate laboratory stress-inducing paradigm.

Background/Aims The interstitial cells of Cajal (ICC) are located within and around the digestive tract’s muscle layers. They function as intestinal muscle pacemakers and aid in the modification of enteric neurotransmission. The appendix’s unique position requires an appropriate contraction pattern of its muscular wall to adequately evacuate its contents. We investigated the development and distribution of nervous structures and ICC in the human fetal appendix. Methods Specimens were exposed to anti-c-kit (CD117) antibodies to investigate ICC differentiation. Enteric plexuses were examined using anti-neuron-specific enolase, and the differentiation of smooth muscle cells was studied with anti-desmin antibodies. Results During weeks 13-14, numerous myenteric plexus ganglia form an almost uninterrupted sequence throughout the body and apex of the appendix. Fewer ganglia were present at the submucosal border of the circular muscle layer and within this layer. A large number of ganglia appear within the circular and longitudinal muscle layers in a later fetal period. The first ICC subtypes noted were of the myenteric plexus and the submucous plexus. In the later fetal period, the number of intramuscular ICC markedly rises, and this subtype becomes predominant. Conclusions The ICC and nervous structure distribution in the human fetal appendix are significantly different from all other parts of the small and large intestine. The organization of ICC and the enteric nervous system provides the basis for the specific contraction pattern of the muscular wall of the appendix. (J Neurogastroenterol Motil 2021;27:127-133)

Introduction: Antioxidants such as lycopene (LCP) and caffeic acid phenethyl ester (CAPE) represent ideal molecules for the treatment of different reactive oxygen species (ROS) associated disorders. Cisplatin is a chemotherapeutic agent, causing an increase in ROS and DNA damage, with numerous side effects, which include lung toxicity. In the presents study, we evaluated and mutually compared the potential of LCP and CAPE in preventing cisplatin-induced rat lung damage. Methods: The study was done using pathohistological analysis and a panel of biochemical parameters that reflect lung oxidative tissue damage, inflammation, and apoptosis. Results: The obtained results suggest that cisplatin (10 mg/kg) causes significant disturbances in the lung tissue morphology, followed by an increase in lipid peroxidization and protein modification. Also, a pronounced inflammatory response and cell apoptosis cascade activation was noted. Both LCP and CAPE were able to mitigate the changes, to a different extent, in oxidative damage and apoptosis progression induced by cisplatin. However, they both had limited effect on inflammation since they only prevented an increase in myeloperoxidase activity but had not been able to prevent the NO generation. Conclusion: It is hard to be exact in saying whether LCP or CAPE is better in preventing cis­platin-induced lung damage since they obviously possess different mechanisms of action.

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.

The aim of our study was to investigate if green tea and bilberry have protective effect on gentamicin-induced kidney damage, when applied together, and to make a connection between their effects. GM group of rats received only gentamicin, GT group received green tea only, B group received only bilberry, whereas control (C) group received saline only. GT+GM group received green tea together with gentamicin, and B+GM group received bilberry together with gentamicin. Biochemical analysis showed significantly increased urea and creatinine levels in GM group when compared to groups that also received bilberry or green tea. Histological analysis showed complete disruption of glomerular basal membrane as well as basal membranes of both proximal and distal tubules in GM group. These destructive effects were significantly milder and limited only to proximal tubules when bilberry or green tea was applied simultaneously with gentamicin. Both green tea and bilberry protective effect on gentamicin-induced nephrotoxicity is manifested because of their strong antioxidant activity. Since they are strong antioxidants, widely distributed in nature, they can offer available and inexpensive adjuvant therapy in Gram-negative infections, which can relieve gentamicin nephrotoxicity, but will not affect its bactericidal effect.

Skeletal muscle tissue is known to be susceptible to oxidative tissue damage that accompanies different disorders. Carbon tetrachloride (CCl4) is dangerous chemical that is used to mimic disorders, in experimental animals, related to reactive oxygen species induced tissue damage. It is well established that antioxidants, both natural and synthetic ones, are able to alleviate tissue damage caused by reactive oxygen species. The aim of the present study was to determine the effects of melatonin (MLT), a strong naturally occurring antioxidant, on changes in Wistar rat skeletal muscle catalase activity acutely induced by CCl4. Gastrocnemius muscle tissue, in which catalase activity was determined, was obtained from three groups of animals i.e. control (untreated), CCl4 treated and MLT and CCl4 group. The results revealed statistically significant decrease in muscle tissue catalase activity in rats exposed to CCl4, while in the group that received MLT and CCl4 this decrease was insignificant. The protective activity of MLT could be contributed to its different mechanisms since it is known to directly scavenge free radicals, increase tissue antioxidant capacity and to up-regulate antioxidant enzyme gene expression.

Carvacrol (5-isopropyl-2-methylphenol) is a biologically active monoterpene phenol abundantly present in the essential oils of many Lamiaceae aromatic/ethnomedicinal plants. Herein, we aimed to evaluate the damaging effect of carvacrol to rat pancreatic tissue, but also to assess its possible ameliorative impact on pancreatic damage induced by L-arginine. The toxic and beneficial (in a dose of 10 mg/kg) properties of carvacrol were assessed by measuring serum α-amylase and lipase activities, tissue malondialdehyde (MDA) content, and pathohistological changes in pancreatic tissue. Application of 100/500 mg/kg of carvacrol produced a significant increase in α-amylase activity, followed by inflammatory-cell infiltration and patchy interlobular edema in the pancreas. In the L-arginine-induced pancreatitis model, a dose of 10 mg/kg of carvacrol prevented an increase in α-amylase and lipase activities, and MDA formation, when compared to the animals that received L-arginine only. Animals treated with carvacrol prior to L-arginine administration displayed mild edema and inflammatory infiltration with few necrotic areas. Contrary to that, animals that received only L-arginine showed a massive leukocyte infiltrate with edema and substantial necrotic areas. In our study carvacrol showed significant protective effects and a potential to modulate leukocyte recruitment in pancreatic tissue after L-arginine injection.

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

We aimed to evaluate whether two methionine-related compounds, S-adenosylmethionine (SAM), and selenomethionine (SM), could lessen liver damage induced by regurgitated bile in a model of rat bile duct ligation (BDL). Hepatoprotective potentials of S-adenosylmethionine and selenomethionine were estimated based on the changes of serum liver damage parameters (aminotransferases, alkaline phosphatase, gamma-glutamyltranspeptidase and lactate dehydrogenase activity, and bilirubin concentration), tissue oxidative [xanthine oxidase (XO) and catalase activity, thiobarbituric acid reactive substances (TBARS) levels] and inflammatory [tumor necrosis factor-alfa (TNF-α) concentration] parameters, and morphological liver tissue alterations that follow cholestasis. The treatment regimens proved themselves able to prevent significant liver damage induced by cholestasis. Both SAM and SM decreased XO activity and TBARS levels and increased catalase activity, while only SM significantly reduced TNF-α concentration. Morphological changes related to bile-induced liver damage were also found to be partially diminished by SAM and SM. In view of the mechanisms of action of the two tested methionine-derived compounds, one might say that SM predominantly acted as an antioxidant, while SAM exerted its activity by potentially modulating different gene expression and protein structures. It is also worth mentioning that this is the first study (to the best of our knowledge) that dealt with the effects of SM on BDL-induced liver injury in rats and of the findings that speak favorably of this powerful antioxidant.

Aim Carbon tetrachloride (CCl4) is an organic chemical that produces different tissue‑damaging effects when ingested or inhaled. Present study aims to determine whether the application of exogenous melatonin, a neurohormone with numerous biological properties, can prevent disturbances in lung tissue antioxidative capacities and arginine metabolism, tissue inflammation and oxidative damage induced by exposure to CCl4 in rats. Methods The effects of melatonin on the changes occurring in rat lung tissue after an acute exposure to CCl4 were studied by monitoring alterations in antioxidant capacities, inflammatory parameters, parameters of arginine metabolism, and lipid and protein oxidative damage. Results The results indicated that melatonin prevents CCl4-induced lung damage by mitigating tissue antioxidant capacity and preventing nitric oxide production through a shift from nitric oxide synthase to arginase. Also, melatonin partially prevented tissue inflammation and molecules' oxidative modification seen after exposure to CCl4. Conclusions The protective activity of melatonin can be attributed to its ability to scavenge both free radicals, as well as to its potential to increase tissue antioxidant capacity. The modulation of inflammatory response through both decrease in tissue inflammatory parameters and influence on arginine-nitric oxide metabolism might be an additional mechanism of action (Tab. 1, Fig. 2, Ref. 33).

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.

IntroductionLiver inflammatory response occurring after toxic chemicals injection, such as cisplatin, causes the aggravation in liver damage. Lycopene, a carotenoid, has previously been proven to possess antioxidant, antiinflammatory and antiapoptotic properties. This study objective was to evaluate for the first time the protective effects of lycopene in cisplatin-induced liver damage based on the disturbances in serum and tissue inflammatory parameters. Also, to confirm the extent of changes in inflammation of the studied tissue, a microscopic analysis will be performed.Material and methodsWistar rats were divided into four experimental groups: (I) control; (II) lycopene (2 mg/kg); (III) cisplatin (10 mg/kg) and (IV) lycopene and cisplatin-treated (2 and 10 mg/kg, respectively) animals. After the experiment, we studied changes in serum liver tissue damage associated parameters (ALT, AST, and γ-GT) and liver inflammatory parameters (NO and TNF-α concentrations, myeloperoxidase and iNOS activity, as well as CD68 expression).ResultsApplication of lycopene prevented a rise in evaluated serum parameters induced by cisplatin, while at the same time it did not cause any harmful effect by itself. Lycopene, alone or in combination with cisplatin, decreased the values of all studied liver inflammatory parameters.ConclusionsWe can conclude that lycopene does not prevent liver tissue inflammatory decalin seen after cisplatin application, however, it prevents tissue damage arising from this cytostatic application.

Excessive everyday use of mobile phones and wireless communication systems has produced life in electromagnetic fields and growing public concern about possible effects on human health. All these devices operate close to the head and body and electromagnetic waves leave part of their energy in the matter through which they pass. There has been a lot of research on the toxic effects of amalgam fillings that are believed to be the main source of human total mercury body burden but there is not sufficient knowledge about the influence of electromagnetic radiation from mobile phone on amalgam filling and how that affects human health. Electrical engineering has the task to produce devices that improve the quality of human life without any negative effects, and to ensure the safety of new products and technologies. Using electromagnetic simulation to obtain electromagnetic quantities in the head and teeth and linking these results to physical and physical-chemical processes in the matter has led to advances in clarifying these issues. In general, the conclusion is that the use of mobile phones can lead to increased absorption of energy and other electromagnetic quantities in teeth and filling of teeth and cause increased release of mercury and toxicological effects to health associated with the intake of mercury in the human organism.

Prostate cancer (PC) is one of the most frequent malignancies. Better biomarkers are constantly wanted, such as those which can help with the prediction of cancer behavior. What is also needed is a marker which may serve as a possible therapeutic target. Oxidative stress (OS), which is a hallmark of cancer, is included in the pathogenesis and progression of PC. We have conducted the present study to determine whether xanthine oxidase/dehydrogenase activity is the source of OS in prostate tissue. We have also determined the concentration of TBA-reactive substances (TBARS) and advanced oxidation protein products (AOPP), as well as the activity of catalase. Xanthine oxidase (XO) activity is significantly higher (p &lt, 0.001) in tumor tissue when compared to the control healthy tissue. The concentration of TBARS (p &lt, 0.001) and AOPP (p &lt, 0.05) are also higher in tumor tissue. Catalase has raised its activity (p &lt, 0.05) versus the control. There is also a strong correlation between XO activity and prostate-specific antigen (PSA) levels in the serum. These results indicate a significant role of XO activity in OS in prostate carcinogenesis, and it could be a possible theranostic biomarker, which can be important for a better understanding of the disease, its evolution, and prognosis. A promising treatment may be using XO inhibitors such as allopurinol as adjuvant therapy.

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.

IntroductionCisplatin is one of the most frequently used chemotherapeutics, which is known to cause both tumor and normal lung tissue damage through the generation of free radicals and cells apoptosis/necrosis. Melatonin is a neurohormone that regulates numerous physiological processes in the body both through receptor pathways and by maintaining tissue redox homeostasis.Material and methodsThe extent of rat lung damage induced by cisplatin and the effects of melatonin on this process was determined based on the pathohistological changes and biochemical disturbances in tissue lipid peroxidation, protein carbonyl modification and in the activity of xanthine oxidase (XO), caspase-3 and DNases.ResultsHistopathological analysis of rat lung tissue obtained from animals that received cisplatin found them to be edematous, with significant deterioration of alveolar epithelium. These morphological changes are accompanied by a significant increase in all studied oxidative stress-related parameters, as well as with the activity of apoptosis-related enzymes. A five-day treatment with melatonin completely prevented a cisplatin-induced increase in oxidative stress-related parameters and in the activity of XO, caspase-3 and alkaline DNase. Also, the histopathological changes observed during microscopic analysis were much less pronounced than in the group that received cisplatin only.ConclusionsThese results can potentially be connected with the ability of melatonin to inhibit the activity of XO, caspase-3 and alkaline DNase and/or its ability to scavenge free radicals, thus preventing lung damage induced by cisplatin.

The inhibition of GABAA can be used in general anesthesia. Although, barbiturates and thiobarbiturates are used in anesthesia, the mechanism of their action hasn’t been established. QSAR modeling is a wieldy used technique in these cases and this study presents the QSAR modeling for a group of barbiturates and thiobarbiturates with determined anesthetic activity. Developed QSAR models were based on conformation independent and 2D descriptors as well as field contribution. As descriptors used for developing conformation independent QSAR models, (SMILES) notation and local invariants of the molecular graph were used. Monte Carlo optimization method was applied for building QSAR models for two defined activities. Methodology for developing QSAR models capable of dealing with the small dataset that integrates dataset curation, “exhaustive” double cross-validation and a set of optimal model selection techniques including consensus predictions was used. Two-dimensional descriptors with definite physicochemical meaning were used and modeling was done with the application of both partial least squares and multiple linear regression models with three latent variables related to simple and interpretable 2D descriptors. Different statistical methods, including novel method - the index of ideality of correlation, were used to test the quality of the developed models, especially robustness and predictability and all obtained results were good. In this study, obtained results indicate that there is a very good correlation between all developed models. Molecular fragments that account for the increase/decrease of a studied activity were defined and further used for the computer-aided design of new compounds as potential anesthetics.

Since cisplatin-induced nephrotoxicity has very important clinical consequences, the purpose of this study was to determine the potential protective effect of aminoguanidine on the acute kidney injury caused by cisplatin. Experiments were done on 40 Wistar rats divided into four groups. The CIS group received cisplatin in a single dose of 8 mg/kg, while the CISAG group received the same dose of cisplatin and aminoguanidine (100 mg/kg) by intraperitoneal injections. Animals in the AG group received only aminoguanidine (100 mg/kg) and those in the C group received saline. Quantitative evaluation of structural and functional alterations in the kidneys was performed by analysis of biochemical and parameters of oxidative stress and by histological and morphometric analysis of renal sections. Histological sections of kidney showed structural damage of proximal tubules and glomeruli that were induced by cisplatin. Morphometric analysis revealed statistically significant differences in the area of proximal tubules and the size and cellularity of glomeruli between the CIS and CISAG groups. Glomerular basement membrane thickness was increased in the CIS group, while aminoguanidine attenuated these changes in the CISAG group of rats. Our results suggest that aminoguanidine acts protectively and repairs structural and functional damage of kidney by engaging the existent antioxidative potential at the level of renal tissue.

Balkan endemic nephropathy (BEN) represents a chronic tubulointerstitial nephropathy which is followed by the progression of kidney fibrosis to end-stage kidney failure. The critical involvement of poisons in food (aristolochic acid (AA), ochratoxin, and heavy metals) and selenium deficiency are among nutritive factors which contribute to the pathogenesis of BEN, due to reactive oxygen species (ROS) liberation and/or decreased antioxidative defence system. The aim of the study is to distinguish a possible systemic and local origin of ROS through the measurement of xanthine oxidase (XO) activity in urine and plasma, along with the determination of the oxidative changes in lipids and proteins. The study included 50 patients with BEN and 38 control healthy subjects. We noted increased levels of both thiobarbituric acid-reactive substances (TBARS) and advanced oxidation protein products (AOPPs) in the plasma of patients with BEN, compared to the control group (p<0.001). The urinary levels of AOPPs were higher in patients with BEN in comparison to the control (p<0.001). The specific activity of XO was significantly lower in plasma and urine in BEN samples, compared to controls (p<0.005). Based on these results, we hypothesize that XO might not be considered a direct systemic or local contributor to ROS production in BEN, most probably because of the diminished kidney functional tissue mass and/or AA-induced changes in purine nucleotide conformation. The increased AOPP and TBARS level in both plasma and urine in BEN may predict ROS systemic liberation with toxic local effects.

Polyamines, spermine, spermidine, and putrescine are ubiquitous in living cells. Polyamines play important roles in cell growth, proliferation, and survival. Our aim was to determine the concentration of the spermine, spermidine, and putrescine in the rat liver during the first 6 months of postnatal life. A total of 45 albino Wistar rats, maintained under controlled temperature (20±2°C) in the animal room facilities were included in this study. On the day 1, 3.5 months, and 6 months of postnatal life, rats were sacrificed by cervical dislocation. Thr liver was removed and washed in the 0.9% solution of sodium chloride. Concentrations of spermine, spermidine, and putrescine were determined. Concentration of polyamines in the liver tissue of the Wistar albino rats aged 1 day, 3.5 months, and 6 months was respectively: spermine (Sp) (33.81 ± 3.04; 128.15 ± 6.62; 74.34 ± 1.12 mg/g of wet weight); spermidine (Spd) (121.92 ± 6.23; 53.34 ± 3.31; 56.32± 1.41 mg/g wet weight); and putrescine (Put) (8.92 ± 0.98; 9.37 ± 0.98; 20.93 ± 1.15 mg/g wet weight). Polyamine concentration in the rat liver fluctuated during postnatal life. The concentration of the spermidine was highest in the rat liver on the first postnatal day, much higher than spermine, this ratio inverted in 3.5 months old rats. The concentrations of the spermidine and spermine were almost equal at the 6 months of the postnatal life. The concentration of putrescine steadily increases during postnatal life.

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. Keywords: Carbon tetrachloride, Melatonin, Skeletal muscles, Oxidative damage

Hyperglycemia mediated oxidative stress and pro-angiogenic molecules such as vascular endothelial growth factor (VEGF) and matrix metalloproteinase 9 (MMP9) are considered important for diabetic retinopathy onset and progression. Melatonin is a pineal hormone that regulates circadian and seasonal rhythms and most likely is involved in regulating glucose metabolism. We aimed to evaluate the potential benefit of melatonin supplementation to the pre-diabetic retina by assessing melatonin effects on lipid peroxidation (thiobarbituric acid reactive substances, TBARS), protein oxidation (advanced oxidation protein products, AOPP) and concentrations of inducible nitric oxide synthase (iNOS), VEGF and MMP9 in the retina of rats with pre-diabetes. Pre-diabetes was induced by streptozotocin (45 mg/kg, i.p.) following nicotinamide injection (110 mg/kg, i.p.). Beside mild hyperglycemia, lower serum insulin, increased fructosamine and lower HDL cholesterol, the present study demonstrated decreased serum melatonin in pre-diabetic rats, as well as, increased concentration of retinal TBARS, AOPP, iNOS, VEGF, and MMP9. Oral supplementation with melatonin (85 μg/animal/day) caused melatonin and HDL cholesterol levels to rise in treated rats and reduced levels of fasting serum glucose and fructosamine. It also affected serum insulin and quantitative insulin sensitivity check index (QUICKI) in treated groups but had no significant effect on non-fasting glucose. Finally, supplementation with melatonin reduced concentrations of TBARS, AOPP, iNOS, VEGF, and MMP9 in significant level, thereby exerting an overall positive effect on oxidative stress and pro-angiogenic signaling in the pre-diabetic retina. Thus, oral melatonin might be considered in an early treatment or in the prevention of retinal changes associated with pre-diabetes.

Up to this date, there has been an ongoing debate about the mode of action of general anesthetics, which have postulated many biological sites as targets for their action. However, postoperative nausea and vomiting are common problems in which inhalational agents may have a role in their development. When a mode of action is unknown, QSAR modelling is essential in drug development. To investigate the aspects of their anesthetic, QSAR models based on the Monte Carlo method were developed for a set of polyhalogenated ethers. Until now, their anesthetic action has not been completely defined, although some hypotheses have been suggested. Therefore, a QSAR model should be developed on molecular fragments that contribute to anesthetic action. QSAR models were built on the basis of optimal molecular descriptors based on the SMILES notation and local graph invariants, whereas the Monte Carlo optimization method with three random splits into the training and test set was applied for model development. Different methods, including novel Index of ideality correlation, were applied for the determination of the robustness of the model and its predictive potential. The Monte Carlo optimization process was capable of being an efficient in silico tool for building up a robust model of good statistical quality. Molecular fragments which have both positive and negative influence on anesthetic action were determined. The presented study can be useful in the search for novel anesthetics.