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Rhodium(I) complexes bearing N-heterocyclic carbene (NHC) ligands have been widely used in catalytic chemistry, but there are very few reports of biological properties of these types of complexes. A series of benzimidazolium salts and their [RhCl(NHC)(COD)] complexes were synthesized. The obtained complexes were synthesized and characterized by elemental analysis, FT-IR, 1H and 13C NMR. All compounds were screened for in vitro cytotoxic activities against a panel of human cancer cells (HT-29 colon, Ishikawa endometrial, and U-87 glioblastoma) using the MTT assay for 48 h of incubation time. Mouse fibroblast cells (L-929) were used as healthy cells. Complexes had exhibited significantly higher cytotoxic activity towards cancer cells than their ligands and complex 2b showed the most selective cytotoxic activity against HT-29 cancer cells (SI;7.05) and Ishikawa cancer cells (SI; more than 9.8). The complexes showed strong in vitro cytotoxic activity against cancer cells, with IC50 values of lower than 10 μM (except 2a against HT-29 (12.8 μM) and 2b against U-87 (11.1 μM)). All complexes (2a–d) showed the highest in vitro cytotoxic activity against Ishikawa endometrial cancer cells with IC50 values of 2.93 ± 0.06

Seven novel naphthalen-1-ylmethyl substituted silver N-heterocyclic carbene (Ag–NHC) complexes (1–7) were synthesized by the interaction of benzimidazolium salts with silver carbonate in dry dichloromethane at room temperature and characterized by means of spectroscopic methods and elemental analysis techniques. The Ag–NHC compounds were tested for their in vitro antibacterial and antifungal activity against Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Enterococcus faecalis, Candida albicans and Candida tropicalis and showed high antimicrobial activities. The synthesized complexes, in particular, demonstrated better results against both fungi and gram-positive bacteria. Keywords: Benzimidazol-2-ylidene, N-Heterocyclic carbene, Silver complex, Antibacterial activity, Antifungal activity

Diisopropilamine-tethered benzimidazolium salts have been prepared as precursors for Ag(I)-NHC and Au(I)-NHC complexes. These NHC ligands were metallated with Ag2O on moderate conditions to give novel silver-NHC complexes. Gold-NHC complexes have been obtained by transmetalation using the silver-NHC precursor. The structures of all compounds were characterized by H-1 NMR, C-13 NMR, IR and elemental analysis techniques. The cytotoxic properties of the silver(I) and gold(I) complexes have been assessed in various human cancer lines, including cisplatin-sensitive and resistant cell. IC50 values of these four complexes were determined by the MTS based assay on three human cancer cell lines (SHSY5Y, HTC116 and HEP3B) and human healthy cell line (HF). These silver and gold N-heterocyclic carbene complexes have been highlighted metal-based cancer therapeutic agent with unique structures and functions. These strategies provide exciting opportunities for discovering new type metalodrug. (C) 2019 Elsevier B.V. All rights reserved.

A series of novel silver(I)-N-heterocyclic carbene complexes have been prepared and fully characterized by spectroscopic methods and X-ray crystallographic analyses. The biological capacity of the synthesized compounds was evaluated in vitro for their anti-microbial, anti-cholinesterase, anti-lipase, anti-diabetic activities in search of potent inhibitors compound. All compounds were tested against two types of fungi and three bacterias. The results proved that most compounds indicated moderate to excellent activity against all types of bacteria and fungi except compound 2f that didn’t show any antibacterial activity. The synthesized compound's capacity to inhibit the enzymes AChE, BChE, Lipase, and α-amylase were evaluated. The results showed that silver(I)–NHC complexes 3a-f are effective against all types of enzymes. The highest activity was reported toward AChE, BChE, and α-amylase enzymes, and at a lower rate against Lipase enzyme compared to the references drug. In contrast, benzimidazolium salts 2a-f, which showed significant inhibitory activity against AChE and BChE enzymes, while all salts were not active against both Lipase and α-amylase enzymes. Molecular docking simulations using AutoDock, have been performed of the new compounds as a representative set of our molecules into AChE and BChE enzymes for lead optimization of the binding interaction template of the most active inhibitors docked into the active site of their relevant AChE and BChE enzymes inhibitors.

It is known that TCDD, one of the most toxic dioxin compounds, causes oxidative damage by forming free radical in human and animal tissues. In this study, the protective effect of PCA, an important phenolic compound, was examined in rat kidney and liver tissues with TCDD-induced toxicity. For this purpose, 28 Wistar Albino rats (3- 4 months old and weighing 280-310 g) were used. Rats were randomly divided into 4 equal groups (control, TCDD, PCA and TCDD+PCA). TCDD and PCA were dissolved in corn oil at doses of 2 µg/kg and 100 mg/kg, respectively. Subsequently, the substances were administered to the rats by oral gavage for 45 days. The test results showed that in both kidney and liver tissues, TCDD increased the level of malondialdehyde (MDA) but inhibited the level of glutathione (GSH) and the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px). PCA administration was found to increase the enzyme activities and GSH levels, whereas it decreased the TCDD and MDA levels. In conclusion, it was observed that PCA decreased the TCDD-induced lipid peroxidation, increasing the antioxidant activity. Therefore, it might be suggested that PCA is a potential reducing agent for the toxicity caused by TCDD. En toksik dioksin bileşiklerinden biri olan TCDD'nin insan ve hayvan dokularında serbest radikal oluşturarak oksidatif hasara neden olduğu bilinmektedir. Bu çalışmada, TCDD tarafından toksisite oluşturulan sıçan karaciğeri ve böbreğinde önemli bir fenolik bileşik olan PCA’nın koruyucu etkileri araştırıldı. Bu amaçla 28 adet Wistar Albino cinsi sıçanlar (3-4 aylık ve 280-310 g ağırlığında) kullanıldı. Sıçanlar kontrol, TCDD, PCA ve TCDD + PCA olmak üzere rastgele 4 eşit gruba ayrıldı. TCDD ve PCA mısır yağı içinde çözüldü ve sırasıyla 2 µg / kg ve 100 mg / kg dozunda 45 gün boyunca gavaj yolu ile sıçanlara uygulandı. Çalışmanın sonunda TCDD'nin malondialdehit (MDA) seviyesini arttırdığı, ancak glutatyon (GSH) seviyesini ve süperoksit dismutaz (SOD), katalaz (CAT) ve glutatyon peroksidaz (GSH Px) aktivitelerini azalttığı gözlendi. PCA uygulamasının TCDD'nin aksine enzim aktivitelerini ve GSH seviyelerini arttırdığı ve MDA seviyelerini düşürdüğü tespit edildi. Sonuç olarak, PCA'nın TCDD'nin neden olduğu lipid peroksidasyonunu azalttığı ve antioksidan aktivitesini desteklediği görülmüştür. Bu nedenle PCA’nın, TCDD'nin neden olduğu toksisiteye karşı potansiyel bir indirgeyici madde olduğu öne sürülebilir.

In this study, two novel benzimidazolium salts consisting propane sulfonate order were integrated in high yields as N-heterocyclic carbene (NHC) precursors. The silver-NHC buildings were set up by responding 1-(2,2-dimethoxyethyl)-3-(propyl-3-sulfonate)benzimidazolium and 1-(2,2-diethoxyethyl)-3-(propyl-3-sulfonate)benzimidazolium with silver oxide on average state. Gold-NHC edifices were acquired by means of transmetallation of their silver precursors with [AuCl{S(CH3)2}]. The structures of all mixes were completely portrayed by spectroscopic techniques (1H NMR, 13C{1H} NMR, IR and elemental and further analyzed by DFT/TDDFT strategies. IC50 values and cytotoxic impacts of these four complexes were controlled by the MTS put together examine with respect to three human cancer cell lines neuroblastoma (SHSY5Y), adenocarcinoma (HEP3B), and human fibroblasts (HF).

Platinum (II) complexes bearing N-heterocyclic carbene (NHC) ligands have been widely used in catalytic chemistry, but there are very few reports of biological properties of this type of complexes. A series of [PtCl2(NHC)(PEt3)] complexes were synthesized. The structures of all compounds were characterized by H-1-NMR, C-13-NMR, IR and elemental analysis techniques, which supported the proposed structures. The single crystal structures of complexes 1a and 1e were determined. The title complexes show slightly distorted square-planar coordination around the platinum (II) metal center. The cytotoxic properties of the platinum (II)-NHC complexes have been assessed in various human cancer lines, including cisplatin-sensitive and resistant cells. IC50 values of these four complexes were determined by the MTS-based assay on three human cell lines-brain (SHSY5Y), colon (HTC116) and liver (HEP3B). These complexes have been highlighted cancer therapeutic agent with unique structures and functions.

We focused our study for the conception and the synthesis of a new series of Silver (I) N-heterocyclic carbene complexes which were obtained from the corresponding N-heterocyclic carbene (NHC) precursors and their unsymmetrical benzimidazolium salts. These new Ag-NHC complexes were screened for their antibacterial, antifungal, and anti-cholinesterase activities. The biological activities of synthesized products were compared with standard drugs. N-heterocyclic carbenes 2a-f and complexes 3a-f exhibited moderate antibacterial and antifungal activities. The results proved that the compounds indicated moderate to excellent activity against both AChE and BuChE. It was found that most of the complexes displayed good AChE and BuChE inhibitory activities. In particular, compounds 3c and 3e were the most potent inhibitors in the series with IC50 values of 8.56 +/- 1.17 mu M and 5.05 +/- 0.30 mu M against AChE and BChE, respectively. Docking studies revealed that compounds 3c and 3e bind manly to the catalytic anionic site (CAS) of the AChE, and BChE respectively. (C) 2021 Elsevier B.V. All rights reserved.

Six new silver complexes containing symmetrical N-heterocyclic carbene (NHC) ligands were synthesized by the reaction of azolium salts with Ag2O in CH2Cl2 . These complexes were tested against Gram-negative bacterial strains (Escherichia coli and Pseudomonas aeruginosa), Gram-positive bacterial strains (Enterococcus faecalis and Staphylococcus aureus), and fungal strains (Candida albicans and Candida tropicalis), and all tested complexes showed good activity against the different microorganisms.

WOS: 000355532300006, PubMed ID: 25931353, Background. The blocking of nitric oxide synthase (NOS) activity may cause vasoconstriction with formation of reactive oxygen species. Propolis is a natural product collected from plants by honeybees. Propolis has biological and pharmacological properties. Objectives. This study was designed to investigate the effects of propolis on catalase (CAT) activity, nitric oxide (NO) and malondialdehyde (MDA) levels in the liver tissues of NOS inhibited rats by N omega-Nitro-L-arginine methyl ester (L-NAME). Material and Methods. Rats were given a NOS inhibitor (L-NAME, 40 mg/kg, intraperitoneally) for 15 days to provoke hypertension and propolis (200 mg/kg, by gavage) the last 5 of the 15 days. Results. Nitric oxide levels in the liver tissue of the rats given L-NAME significantly decreased (p < 0.01). That parameter did not significantly alter in the liver of rats treated with propolis compared to the control group. CAT activity and MDA levels in the liver of the rats administrated L-NAME significantly increased compared to the control group (p < 0.01). These parameters significantly decreased in the liver of the rats given L-NAME + propolis compared to the L-NAME group (p < 0.01). Conclusions. The present data shows that L-NAME in the liver may enhance oxidative stress via inhibited nitric oxide synthase. Our results also suggest that this effect is suppressed by the antioxidant properties of propolis in the liver tissue of NOS inhibited rats, Nigde University Research Fund [BAP 2008/25], The Nigde University Research Fund (BAP 2008/25) is gratefully acknowledged for supporting this work.

A series of novel benzimidazolium bromides containing bulky 3,5-di-tert-butyl group were synthesized in high yields as N-heterocyclic carbene (NHC) ligands. These NHC ligands were metallated with Ag2O under moderate conditions to give novel silver–NHC complexes. The structures of all compounds were characterized using 1H NMR, 13CNMR, infrared and elemental analysis techniques, which supported the proposed structures. The silver–NHC complexes were screened for their in vitro antimicrobial activities against the standard bacterial strains Enterococcus faecalis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa and the fungal strains Candida albicans and C. tropicalis. The results showed that most of the silver–NHC complexes inhibited the growth of all bacterial strains and fungal strains and were found to display effective antimicrobial activity against different microorganisms.

Six new 2-morpholinoethyl and 2-diethylaminoethyl substituted N-heterocyclic carbene (NHC) silver complexes (2a-f) were synthesized from the reaction 1-(2-morpholinoethyl)-3-napthalenomethlbenzimidazolium chloride (1a), 1-(2-morpholinoethyl)-3-(2-methylbenzyl)benzimidazolium chloride (1b), 1-(2-morpholinoethyl)-3-(2,3,5,6-tetramethylbenzyl)benzimidazolium chloride (1c), [1-(2-diethylaminoethyl)-3-(3-methylbenzyl)benzimidazolium chloride (1d), [1-(2-diethylaminoethyl)-3-(2,3,5,6-tetramethylbenzyl)benzimidazolium chloride (1e), [1-(N,N-diethylethane)-3-(2,3,4,5,6-pentamethylbenzyl)benzimidazolium chloride (1f) with silver oxide (Ag2O) in dichloromethane at room temperature. These silver complexes were characterized by means of 1H NMR, 13C NMR, FT-IR spectroscopy and elemental analysis techniques. Also, [1-(N,N-diethylethane)-3-(2,3,4,5,6-pentamethylbenzyl)benzimidazol-2-ylidene]chlorosilver(I) complex (2f) was characterized by means of LC-MS and Maldi-MS methods. All silver complexes (2a-f) were screened fo...

2-Methoxyethyl, 2-diethylaminoethyl, and 2-phenylethyl-substituted N-heterocyclic carbene (NHC) precursors were treated with Ag2CO3 to yield silver(I)-NHC complexes (1a--g) in dichloromethane as a solvent at room temperature. The 7 new silver-NHC complexes were fully characterized by means of 1H NMR, 13C NMR, and elemental analysis techniques. Using the agar dilution procedure recommended by the Laboratory and Clinical Standards Institute, the antimicrobial activities of all the silver-NHC complexes were studied against 2 gram-negative bacterial strains (Pseudomonas aeruginosa and Escherichia coli), 2 gram-positive bacterial strains (Enterococcus faecalis and Staphylococcus aureus), and 2 fungi (Candida tropicalis and Candida albicans).

This study reports the synthesis, characterisation and antimicrobial activity of five novel silver N-heterocyclic carbene (Ag–NHC) complexes obtained by N-propylphthalimide and N-methyldioxane substituted benzimidazolium salts with silver oxide. The reactions were performed at room temperature for 24 h in the absence of light. The obtained complexes were identified and characterised by 1H and 13C NMR, FT-IR and elemental analysis techniques. The minimum inhibitory concentration (MIC) of the complexes was determined for E. coli, P. aeruginosa, E. faecalis, S. aureus, C. tropicalis and C. albicans in vitro through agar and broth dilution. The results indicated that these complexes exhibit antimicrobial activity. In particular, complex 3 presented the significant broad spectrum antimicrobial activity.

Benzimidazolium salts and six anionic gold-NHC complexes (NHC = N,N'-dialkylbenzimidazol-2-ylidene) were prepared and characterized. Novel [Au(NHC)(2)]AuCl2-type complexes were prepared in good yields from silver-NHC complexes by treatment with [AuCl(PPh3)], following the commonly used silver carbene transfer route. All compounds were characterized using H-1 and C-13 NMR spectroscopy, elemental analysis, and IR. The gold complexes showed antimicrobial activity against Gram-positive/negative and fungal strains.

WOS: 000317523000007, PubMed ID: 22287620, Objective: The aim of this study was to evaluate the chemopreventive potential of organoselenium compounds (Se I and Se II) in the well-established rat model treated with 7,12-dimethylbenz[a]anthracene (DMBA), by monitoring the extent of tyrosine hydroxylase (TH) activity, adrenomedullin (ADM) level and total RNA level in adrenal medulla. Organic pollutants are the most important environmental factor for the biologic systems. DMBA exposure appears to be associated with a number of physiological disease processes. Methods: The effects of Se I and Se II compounds were investigated on TH activity, ADM and total RNA levels in adrenal medulla of rats exposed to DMBA. Results: TH activity, ADM and total RNA levels were found to be increased significantly due to the effect of DMBA (p < 0.05). This increase was restricted in the Se I-and Se II-treated groups (p < 0.05). Conclusion: The present data showed that the organoselenium compounds may have important effects in the maintainance of homeostasis against stress induced by DMBA., Inonu University [BAP 2005/60], This work was supported by Inonu University Research Fund (BAP 2005/60).

The synthesis and antimicrobial studies of 1-methyl-2-dimethylaminoethyl-substituted carbene precursors and silver complexes are reported. The carbene precursors (1a–d) have been prepared from 1-methyl-2-dimethylaminoethyl-substituted benzimidazole and various alkyl halides. The silver–NHC complexes (2a–d) were synthesized from the benzimidazolium salts and Ag2O in dichloromethane at room temperature. The new compounds were characterized by 1H NMR, 13C NMR, FT-IR, and elemental analyses. The new carbene precursors and Ag-complexes were tested for their in vitro antimicrobial activity against a variety of Gram-positive and Gram-negative bacteria, as well as for their antifungal activities against Candida albicans and Candida tropicalis.

The aim of this study is to investigate the beneficial effects of the quercetin (Q) and chrysin (CH) against nephrotoxicity induced by 2,3,7,8-tetrachlorodibenzo- p-dioxin (TCDD), a persistent environmental contaminant, in rats. Rats were divided randomly into six equal groups. TCDD, Q and CH were administered by gavages dissolved in corn oil at the doses of 2 µg/kg/week, 20 mg/kg/day and 50 mg/kg/day, respectively. The kidney samples were taken from all rats on day 60 for the determination of thiobarbituric acid reactive substances (TBARS), glutathione (GSH), catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD) levels by spectrophotometric method. The results indicated that TCDD significantly induced lipid peroxidation and reduced antioxidant activities in rats. In contrast, Q and CH significantly prevented toxic effects of TCDD via increased GSH, CAT, GPx and SOD levels but decreased formation of TBARS. Also, it was determined that exposure to TCDD leads to significant histological damage in kidney tissue, and these effects can be eliminated with Q and CH treatment. In conclusion, the current study showed that exposure to TCDD can exert nephrotoxicity in rats. When Q and CH were given together with TCDD, they prevented nephrotoxic effects of TCDD. Their preventive effect lends more support to the role of oxidative and histological damage in the overall toxicity of TCDD.

The objective of current study is to investigate the effects of the administration of chrysin (CH) and quercetin (Q) on rat liver in which oxidative and histological damage had been induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Rats were randomly divided into six equal groups. TCDD was orally administered at the dose of 2 μg/kg/week, and Q and CH were orally administered at the doses of 20 mg/kg day and 50 mg/kg/day, respectively, by gavages dissolved in corn oil. The liver samples to be analyzed for the determination of oxidative and histological alternations were taken from rats at 60 days. The results indicated that although 2,3,7,8-TCDD significantly induced (P ≤ 0.01) lipid peroxidation (increase of MDA levels), it positively affected oxidant/antioxidant system (a decline in the levels of GSH, CAT, GSH-Px, and CuZn-SOD) in rats significantly. The histological changes observed in the liver correlated with the biochemical findings. However, these effects of TCDD on oxidative and histological changes were eliminated by Q and CH treatment. In conclusion, TCDD caused an adverse effect on rat's liver. When Q and CH were given together with TCDD, they prevented hepatotoxicty induced by TCDD. Thus, it is thought that Q and CH may be useful as a new category of anti-TCDD toxicity agent. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2013.

The aim of this study was to investigate the effectiveness of curcumin, β-myrcene (myrcene) and 1,8-cineole (cineole) on antioxidant defense system in rats given a persistent environmental pollutant (2,3,7,8-tetrachlorodibenzo-p-dioxin, TCDD). Rats (n = 112) were divided randomly into 8 equal groups. One group was kept as control and given corn oil as carrier. TCDD was orally administered at the dose of 2 μg/kg/week. Curcumin, myrcene and cineole were orally administered at the doses of 100 mg/kg/day, 200 mg/kg/day and 100 mg/kg/ day, respectively, by gavages dissolved in corn oil with and without TCDD. The liver samples were taken from half of all rats on day 30 and from the remaining half on day 60 for the determination of thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH), catalase (CAT), glutathione peroxidase (GSH-Px) and CuZn-SOD levels by spectrophotometric method. The results indicated that although TCDD significantly (p ≤ 0.01) increased formation of TBARS, it caused a significant decline in the levels of GSH, CAT, GSH-Px and CuZn-SOD in rats. In contrast, curcumin, myrcene and cineole significantly increased GSH, CAT, GSH-Px and CuZn-SOD levels but decreased formation of TBARS. Additionally, the antioxidative effects of curcumin, myrcene and cineole were increased at day 60 compared to day 30. In the TCDD groups given curcumin, myrcene and cineole, oxidative stress decreased by time. In conclusion, curcumin, myrcene and cineole showed antioxidant activity and eliminated TCDD-induced oxidative stress in rats in a time-dependent manner.

The aim of this study is to investigate the effects of the quercetin (Q) and chrysin (CH) on oxidative stress, cytokines levels and body weights in rats induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Rats were divided randomly into six equal groups. TCDD, Q and CH were administered by gavages dissolved in corn oil at the doses of 2 µg/kg/week, 20 mg/kg/day and 50 mg/kg/day, respectively. The blood samples were taken from all rats at 60th days to be analyzed for the determination of thiobarbituric acid reactive substances (TBARS), tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ). The results indicated that although TCDD increased significantly TBARS and TNF-α levels, it caused a decline in the levels of IFN-γ and body weight. In contrast, these effects of TCDD on TBARS, TNF-α, IFN-γ levels and body weight were significantly prevented by treatments of Q and CH. In conclusion, it was determined that TCDD caused the adverse effects on immune functions, body weight and oxidative stress in rats. However, Q and CH administered with TCDD eliminated these adverse effects. These results suggest that Q and CH may play a protective role against TCDD toxicity.

Novel benzimidazol-2-ylidene carbene complexes of Ag(I) were prepared by interaction of the corresponding benzimidazolium salt with Ag2O in dichloromethane. Their structures were characterized by elemental analyses, 1H-NMR, 13C-NMR and IR spectroscopy techniques. All compounds studied in this work were screened for their in vitro antimicrobial activities against the standard strains: Enterococcus faecalis (ATCC 29212), Staphylococcus aureus (ATCC 29213), Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853) and the fungi Candida albicans and Candida tropicalis. The new complexes were found to be effective antimicrobial activity against a series of bacteria and fungi. Copyright © 2010 John Wiley & Sons, Ltd.

A series of imidazolidinium ligand precursors are metallated with Ag2O to give silver(I) N-heterocyclic carbene complexes. All compounds were fully characterized by elemental analyses, 1H-NMR, 13C-NMR and IR spectroscopy techniques. All compounds studied in this work were screened for their in vitro antimicrobial activities against the standard strains: Enterococcus faecalis (ATCC 29212), Staphylococcus aureus (ATCC 29213), Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853) and the fungi Candida albicans and Candida tropicalis. The new imidazolidin-2-ylidene silver complexes have been found to display effective antimicrobial activity against a series of bacteria and fungi.

Gold(I) N-heterocyclic carbene (NHC) complexes were obtained in good yields from the corresponding silver complexes by treatment with [AuCl(PPh3)] following the commonly used silver carbene transfer route. The silver complexes were synthesized from the benzimidazolium halide salts by the in situ reactions with Ag2O in dichloromethane as a solvent at room temperature. All gold complexes have been characterized by H-1-NMR, C-13-NMR and IR spectroscopy and elemental analysis. Au-NHC complexes were evaluated for their in vitro antimicrobial activity against a variety of Gram-positive and Gram-negative bacteria and fungal species.

WOS: 000258550400009, PubMed: 17920681, Chemical toxic pollutants (especially heavy metals) are important sources of reactive oxygen species (ROS) in biological systems. Membrane phospholipids of aerobic organisms are continually subjected to oxidant challenges from endogenous and exogenous sources, while peroxidized membranes and lipid peroxidation products represent constant threats to aerobic cells. The primary antioxidant protection against free radical and ROS is provided by the enzymes glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase (CAT), respectively. The trace element selenium has been implicated in chemo-prevention and drug-resistance through reduction of oxidative stress. Selenium could prevent damage to the unsaturated fatty acid Of subcellular membranes by lipid peroxidation induced by free radicals. The results reported here show that sodium selenite has an important contribution to antioxidative defense for the spleen and heart of rainbow trout. The ability of sodium selenite to prevent the oxidative stress induced by heavy metals (Cd2+, Cr3+) in fish was rationalized. (C) 2007 Elsevier Inc. All rights reserved., Inonu University Research Fund [BAP 2004/27], This work was supported by Inonu University Research Fund (BAP 2004/27).

Novel benzimidazolium salts were synthesized as N-heterocyclic carbene (NHC) precursors, these NHC precursors were metallated with Ag2O in dichloromethane at room temperature to give novel silver (I)-NHC complexes. Structures of these benzimidazolium salts and silver(I)-NHC complexes were characterized on the basis of elemental analysis, H-1 NMR, C-13 NMR, IR and LC-MS spectroscopic techniques. A series of benzimidazolium salts and silver(I)-NHC complexes were tested against standard bacterial strains: Enterococcus faecalis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and the fungal strains: Candida albicans and Candida tropicalis. The results showed that benzimidazolium salts inhibited the growth of all bacteria and fungi strains and all silver(I)-NHC complexes performed good activities against different microorganisms. (C) 2016 Elsevier Ltd. All rights reserved.

Eight new coumarin substituted silver(I) N-heterocyclic carbene (NHC) complexes were synthesized by the interaction of the corresponding imidazolium or benzimidazolium chlorides and Ag2O in dichloromethane at room temperature. Structures of these complexes were established on the basis of elemental analysis, (1)H NMR, (13)C NMR, IR and mass spectroscopic techniques. The antimicrobial activities of carbene precursors and silver NHC complexes were tested against standard strains: Enterococcus faecalis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and the fungi Candida albicans and Candida tropicalis. Results showed that all the compounds inhibited the growth of the all bacteria and fungi strains and some complexes performed good activities against different microorganisms. Among all the compounds, the most lipophilic complex bis[1-(4-methylene-6,8-dimethyl-2H-chromen-2-one)-3-(naphthalene-2-ylmethyl)benzimidazol-2-ylidene]silver(I) dichloro argentate (5e) was found out as the most active one.

The aim of this study is synthesis of two different series of organoselenium compounds and available in vitro antioxidant and antimicrobial properties of these synthetic compounds. The synthetic compounds were identified by (1)H-NMR (300 MHz), (13)C-NMR (75.5 MHz), FT-IR spectroscopic techniques and micro analysis. Antioxidant properties of two synthetic organoselenium compounds were determined by 1,1- diphenyl-2-picrylhydrazyl (DPPH) radical method, reducing power assay and β-carotene bleaching method as in vitro. Antimicrobial effects of samples were assessed by the agar dilution procedure and using gram positive and gram-negative bacteria and yeast strains. Although 1,3-di-p-methoxybenzylpyrimidine-2-selenone showed better antiradical activity in DPPH test and higher protective activity on β-carotene, 1-isopropyl-3-methylbenzimidazole-2-selenone was found to be better in reducing power and antimicrobial activity.

The balance between prooxidants and antioxidants is crucial to the survival and functioning of aerobic organisms. Partially reduced derivatives of oxygen, which are produced in aerobic organisms as part of normal physiological and metabolic processes, are toxic species, oxidizing numerous biomolecules, which initiate tissue injury and cell death. DMBA (7,12-dimethylbenz[a]anthracene) is a polycyclic aromatic hydrocarbon (PAH) known to cause tumors in rats. DMBA is known to generate DNA-reactive species, which may enhance oxidative stress in cells, during its metabolism. Besides the formation of DNA adducts, oxidative products derived from mutagen metabolism, such as DMBA, might impair vital cellular functions by damaging proteins and lipid membranes. Synthetic organoselenium compounds inhibit the initiation phase of carcinogenesis by inhibiting DMBA-DNA adduct formation in the target organ in vivo. Because of the health problems induced by many environmental pollutants, many efforts have been undertaken to evaluate the relative antioxidant potential of selenium and synthetic organoselenium compounds. We undertook the present study to evaluate the chemopreventive potential of the novel synthetic organoselenium compounds (1-isopropyl-3-methylbenzimidazole-2-selenone (SeI) and 1,3-di-p-methoxybenzylpyrimidine-2-selenone (SeII)) in the well-established DMBA-treated rat model by monitoring the extent of lipid peroxidation and mammary duct damage. In this study, adult female Wistar rats were treated with DMBA and the novel organoselenium compounds (SeI and SeII) in determined doses. In DMBA-treated rats, the effects of the organoselenium compounds on malondialdehyde (MDA) levels and histological changes in the rat mammary lactiferous duct were studied. The ability of the organoselenium compounds to prevent oxidative damage induced by DMBA in rat mammary ducts was demonstrated. Protection against lipid peroxidation measured as MDA in the SeI and SeII treated groups was provided by the novel synthesized organoselenium compounds. SeI and SeII both provided chemoprevention against DMBA-induced oxidative stress in the rat mammary duct.

WOS: 000344603300009, PubMed ID: 24490594, Nitric oxide (NO), produced by endothelial NO synthase, is recognised as a central antiinflammatory and antiatherogenic principle in the vasculature. Epidemiological and clinical studies have demonstrated that a growing list of natural products, as components of the daily diet or phytomedical preparations, may improve vascular function by enhancing NO bioavailability. In this article, we investigated antioxidant effects of propolis on biochemical parameters in kidney and heart tissues of acute NO synthase inhibited rats by N-omega-nitro-L-arginine methyl ester (L-NAME). There was increase (p < 0.001) in the activities of catalase and malondialdehyde levels in the L-NAME treatment groups when compared with control rats, but NO levels were decreased in both kidney and heart tissues. There were statistically significant changes (p < 0.001) in these parameters of L-NAME + propolis treated rats as compared with L-NAME-treated group. In summary, propolis may influence endothelial NO production., Nigde University Research Fund [BAP 2008/25], The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper. Nigde University Research Fund (BAP 2008/25) is gratefully acknowledged for support of this work.

WOS: 000308422300007, PubMed ID: 22471835, Reduction in the synthesis or bioavailability of nitric oxide plays a significant role in the development of hypertension. Propolis is a resinous product collected by honeybees from various plant sources. Tyrosine hydroxylase (TH) is the rate-limiting enzyme in the biosynthesis of catecholamines. The aim of this study was to examine the effect of propolis on blood pressure (BP), TH, and total RNA levels in the adrenal medulla, heart, and hypothalamus tissues in chronic nitric oxide synthase (NOS)-inhibited rats by N-w-nitro-L-arginine methyl ester (L-NAME). Rats received NOS inhibitor (L-NAME) for 15 days to produce hypertension and propolis for the last 5 days. TH activity and total RNA levels significantly increased in adrenal medulla, heart, and hypothalamus tissues in L-NAME-treated groups (P < .05). TH activity and total RNA levels of L-NAME+propolis-treated rats reduced (P < .05) compared with L-NAME-treated groups. TH activity in propolis-treated rats was reduced to the control values. L-NAME led to a significant increase in BP compared with the control group. Propolis administration to L-NAME-treated rats reduced BP but this was not statistically significant compared to L-NAME-treated groups. These results suggest that propolis decreases TH activity in NOS-inhibited hypertensive rats and thereby may modulate the synthesis of catecholamine and BP., Nigde University [BAP 2008/25], The Nigde University Research Fund (BAP 2008/25) is gratefully acknowledged for supporting this work. The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.

A series of-unsymmetrical N,N-disubstituted benzimidazolium salts were synthesized as N-heterocyclic carbene (NHC) precursors. These compounds were used to synthesize of N-heterocyclic carbene silver(I) complexes. New compounds were characterized by NMR and IR spectroscopies and elemental analyses. The antibacterial activity of all the compounds was tested against Gram (+)/(-) and fungal strains using the agar dilution procedure. (C) 2012 Elsevier B.V. All rights reserved.

In the present study, we aimed to determine the oxidative damage in rat heart tissue induced by ruthenium(II)-NHC (Ru) and gold(I)-NHC (Au) complexes which have anticarcinogenic effects and not used clinically yet. For this purpose, 35 Sprague-Dawley rats were randomly divided into 5 equal groups. In the control group, rats treated with saline, Ru and Au complexes were intraperitoneally given high (10 mg/kg) and low (5 mg/kg) doses as only one administration. The animals were killed, and heart tissues were taken on day 10 of the drug administration for the determination of the biochemical parameters (malondialdehyde, superoxide dismutase, reduced glutathione and catalase levels). It was determined that both Ru and Au complexes treatment significantly caused oxidative damage compared to the control group. Additionally, it was shown that Au treatment caused more adverse effects than Ru treatment. Also, it was clearly found that the occurred effects were generally determined in a dose-dependent manner. In conclusion, when these compounds synthesized for the treatment of cancer were used, they caused oxidative damage in heart tissue. However, Ru complex could be preferred for cancer treatment in terms of user safety.

Cis-platin and other platinum complexes are important chemotherapeutic agents useful in the treatment of several cancers. However, therapeutic usage of cis-platin and other platinum complex are limited by their undesirable side effects including cardiotoxicity. In this context, we aimed to compare the damage caused in heart by cis-platin and novel platinum- N-heterocyclic carbene (Pt-NHC) complex. For this purpose, 35 Sprague-Dawley rats were divided randomly into five equal groups ( n = 7 for each group). Cis-platin and novel Pt-NHC complex were intraperitoneally administered at a single dose of 5 mg/kg and 10 mg/kg and then sacrificed 10 days after this treatment. The heart tissues were taken from all rats for determination of oxidative and myocardial damage. Cis-platin and novel Pt-NHC complex caused oxidative and histological damage in the heart tissue in a dose-dependent manner ( p < 0.05). On the other hand, at the same dose levels, cis-platin caused lower oxidative and histological damage in heart tissue compared to novel Pt-NHC complex. These results suggest that novel Pt-NHC complex is more cardiotoxic than cis-platin.

DMBA (7, 12-dimethylbenz[a]anthracene) is known to generate DNA-reactive species during their metabolism, which may enhance oxidative stress in cells. Since selenium is known as a non-enzymic antioxidant, health problems induced by many environmental pollutants, have stimulated the evaluation of relative antioxidant potential of selenium and synthetic organoselenium compounds. Therefore, we aimed to evaluate chemopreventive potential of synthetic organoselenium compounds by monitoring level of liver nitric oxide. In this study, adult female Wistar rats were treated with DMBA and the novel organoselenium compounds (Se I) and (Se II) in the determined doses. DMBA-induced in rats, the effects of organoselenium compounds on nitric oxide levels in rat liver was studied. In this study it has been observed a statistically significant increase in (Nitric Oxide) levels for the liver of rat exposed to DMBA (p0.05). However with administration of Se I and Se II there was a statistically significant decrease in NO levels (p0.05). The ability of the organoselenium compounds to prevent oxidative damage induced by DMBA in rat livers was rationalized. Protection against nitric oxide measured in Se I and Se II treated groups were provided by synthesized organoselenium compounds. Se I and Se II both provided chemoprevention against DMBA-induced oxidative stress in rat liver.

Synthesis, structure, and antimicrobial studies of silver complexes of N-heterocyclic carbene (NHC) are reported. All the silver-NHC complexes (1a-f) were prepared from the benzimidazolium salts by the reactions with Ag2O in dichloromethane as a solvent at room temperature. The new compounds characterized by H-1 NMR, C-13 NMR, IR and elemental analysis techniques which support the proposed structures. Chloro[1-(2,4,6-trimethylbenzyl)-3-(methoxyethyl) benzimidazol-2-ylidene] silver(I) complex was structurally characterized by single-crystal X-ray diffraction. A series of new Ag-NHC complexes were screened for their in vitro antimicrobial activity against a variety of Gram-positive and Gram-negative bacteria as well as for their antifungal activity against a Candida albicans and Candida tropicalis. (c) 2010 Elsevier B. V. All rights reserved.

WOS: 000273920500021, PubMed ID: 19706312, Synthetic organoselenium compounds can be tailored to achieve greater chemopreventive efficacy with minimal toxic side effects by structural modifications. Two organoselenium compounds (Se I and Se II) were synthesized and evaluated for their antihypertensive and therapeutic properties by adrenomedullin (ADM) levels and tyrosine hydroxylase (TH) activity assays in rat heart tissue. 7,12-Dimethylbenz[a]anthracene (DMBA) is known to generate DNA-reactive species during their metabolism, which may enhance oxidative stress in cells. TH is thought to be a rate-limiting enzyme in the biosynthesis of catecholamines. ADM, a potent endogenous vasodilating and natriuretic peptide, may play an important role in the pathophysiology of chronic heart failure. The effects of Se I and Se II were investigated on TH activity, ADM and total RNA levels in the hearts of albino Wistar rats. TH activity was found to be increased significantly by the effect of DMBA (P < 0.05). This increase was restricted in the Se I and Se H treated groups. ADM level was found to be decreased insignificantly by the effect of DMBA (P > 0.05). Total RNA level was found to be decreased significantly by the effect of DMBA (P < 0.05). This study demonstrates that synthetic organoselenium compounds can regulate DMBA-induced stress related changes in rat heart. (C) 2009 Elsevier B.V. All rights reserved., Inonu University [BAP 2005/60], Inonu University Research Fund (BAP 2005/60) is gratefully acknowledged for support of this work.

WOS: 000263762100036, PubMed ID: 18222543, The effects of environmental chemicals, drugs, and physical agents on the developing lung and kidney are influenced by the state of development and maturation. Selenium is an essential element with physiological nonenzymatic antioxidant properties. Therefore, we undertook the present study to evaluate the antioxidant potential of the novel synthetic organoselenium compounds (Se I and Se II). In this study, adult female Wistar rats were treated with DMBA and the novel organoselenium compounds [1-isopropyl-3-methylbenzimidazole-2-selenone (Se I) and 1,3-di-p-methoxybenzylpyrimidine-2-selenone (Se II)] in the determined doses. The protective effects of novel synthetic organoselenium compounds (Se I and Se II) against DMBA-induced changes in levels of some [superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR) activities and total glutathione (GSH), malonedialdehyde (MDA)] parameters in rat lung and kidney were investigated. As a result, it was found that both Se I and Se II had provided the antioxidant effects against DMBA-induced oxidative stress in rat lung and kidney and lipid peroxidation had also been decreased by these organoselenium compounds. (c) 2007 Elsevier Inc. All rights reserved., Technological and Scientific Research Council of Turkey TUBITAK [TBAG-2259, 102T185], We thank to Technological and Scientific Research Council of Turkey TUBITAK TBAG-2259 (102T185) for financial support of this work.

WOS: 000255321300011, PubMed: 18375834, DMBA (7,12-dimethylbenz[a]anthracene) is a polycyclic aromatic hydrocarbon (PAH) known to cause tumors in rats. Selenium is an essential element with physiological nonenzymatic antioxidant properties. Because of the health problems induced by many environmental pollutants, many efforts have been undertaken in evaluating the relative antioxidant potential of selenium and synthetic organoselenium compounds. In this study, adult female Wistar rats were treated with DMBA and the novel organoselenium compounds (1-isopropyl-3-methylbenzimidazole-2-selenone [Sel] and 1,3di-p-methoxybenzylpyrimidine-2-selenone [Sell]) in the determined doses. The protective effects of novel synthetic organoselenium compounds (Sel and Sell) against DMBA-induced changes in superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR) activities and total glutathione (GSH) and malonedialdehyde (MDA) levels of rat heart and brain were investigated. It was determined that Sel and Sell fully or partially restored enzyme activity. It was also found that lipid peroxidation was also decreased in Sel and Sell treated groups. Consequently, it was determined that novel synthetic organoselenium compounds (Sel and Sell) provided protection of antioxidant activity, and protection against lipid peroxidation measured as MDA in Sel and Sell treated groups was provided by novel synthesized organoselenium compounds. The ability of the organoselenium compounds to prevent oxidative damage induced by DMBA in rats was rationalized.

WOS: 000264463000009, PubMed ID: 18974938, Formation of free radicals is not limited to normal cellular process but also occur upon exposure to certain chemicals (polycyclic aromatic hydrocarbon, cadmium, lead, etc.), cigarette smoke, radiation, and high-fat diet. Free-radical damage is an important factor in many pathological and toxicological processes. Selenium, an essential micronutrient, is a associated with antioxidant functions, physiological defense mechanisms against different diseases including several types of cancers. Search for new selenium compounds with more chemopreventive activities and less toxicities are in progress. In addition, there has been a growing interest in the synthesis of organoselenium compounds with respect to their use in enzymology and bioorganic chemistry. In the present study, adult female Wistar rats were treated with 7,12-dimethylbenz[a]anthracene (DMBA) and the organoselenium compounds [1-isopropyl-3-methylbenzimidazole-2-selenone (Se I) and 1, 3-di-p-methoxybenzylpyrimidine-2-selenone (Se II)] in determined doses. The protective effects of synthetic organoselenium compounds (Se I and Se II) against DMBA-induced changes in antioxidant enzyme (superoxide dismutase, glutathione peroxidase (GSH-Px), catalase (CAT), glutathione reductase (GR)) activities, total GSH, and malondialdehyde (MDA) levels of rat erythrocyte were investigated. The DMBA-treated group exhibited significant decreases in the levels of erythrocyte GSH-Px, CAT, and GR activities, an increase in MDA levels, and a decrease in total GSH level compared to the control. Se I and Se II fully or partially restored enzyme activity. Lipid peroxidation was also decreased in Se-I- and Se-II-treated groups.

WOS: 000258086500004, PubMed ID: 18665459, The main purpose of this study is to discuss the effect of Cd+2, Cr+3 and Se metals on biochemical parameters in liver tissue of Oncorhynchus mykiss. The rainbow trout were exposed to heavy metal stress ( Cd+2, Cr+3) at 2 ppm dosage. The present study was undertaken to determine the protective effect of selenium treatment at the same dosage ( 2 ppm) on some biochemical parameters. The activity of catalase ( CAT), glutathione peroxidase ( GSH-Px), superoxide dismutase ( SOD) and the changes in levels of malondialdehyde ( MDA) from biochemical parameters were determined in liver tissue of the fish groups exposed to heavy metals, especially for the selenium-applied groups. Results of this study showed that the activities of CAT, GSH-Px and SOD in the tissues of fish exposed to the stress of Cd+2 and Cr+3 were significantly lower than the control groups ( P < 0.05). Meanwhile, the closer values to the control groups were obtained in selenium-added groups ( Cr+3 + Se+4, Cd+2 + Se+4). For the level of MDA, the last production of lipid peroxidation showed increases ( P < 0.05) in the groups exposed to the metal stress, whereas significant decreases were obtained in selenium-applied groups. The result of the statistical evaluation showed that the negative effects occurring in the biochemical parameters of the applied groups exposed to the toxicity of heavy metal were significantly eliminated ( P < 0.05) as a result of selenium treatment.

Cardiotoxicity is the main complication of adriamycin (ADR), which is a widely used chemotherapeutic agent.To examine the potential cardioprotective effect of melatonin (MEL) on acute ADR cardiotoxicity in a rat model.Cardioprotection was assessed on the basis of myocardial lipid peroxidation and ultrastructure. Rats were given MEL at a daily dose of 5 mg/kg and ADR 15 mg/kg, intraperitoneally. The MEL-1 group rats received one dose and the MEL-7 group rats six daily doses of MEL and were sacrificed at the end of one and seven days, respectively. Rats in the ADR-1 and ADR-7 groups were each given a single dose of ADR, and were then sacrificed 24 h and seven days later, respectively. The MEL+ADR-1 group rats received one dose each of ADR and MEL simultaneously and were sacrificed 24 h later. The MEL+ADR-7 group received a single dose of ADR plus a daily MEL dose for six consecutive days, and were sacrificed seven days after the ADR injection.Lipid peroxidation products were elevated in both ADR-1 and ADR-7 groups, and this elevation was significantly inhibited by MEL treatment. Electron microscopy confirmed that ADR was positively cardiotoxic after one and seven days of exposure. The extent of ADR-induced myocardial damage was markedly reduced when MEL was combined with ADR (MEL+ADR-1 and MEL+ADR-7).The results suggest that MEL is highly efficacious at reducing the acute cardiotoxic effects of high dose ADR, and that it acts by preventing lipid peroxidation.