Azaanalogues of ebselen as antimicrobial and antiviral agents: synthesis and properties.

The different analogues of ebselen-unsubstituted benzisoselenazol-3(2H)-one (2a) 2-pyridylbenzisoselenazol-3(2H)-ones (2b-h) and 7-azabenzisoselenazol-3(2H)-ones (3a-j) were designed as new selenium-containing antiviral and antimicrobial agents and synthesized. Some of them were found in the antiviral assay in vitro to be strong inhibitors of cythopatic activity of herpes simplex virus type 1--HSV-1 (compounds 2a,b,f,h, 3a-j) and encephalomyocarditis virus--EMCV (compounds 2a,h, 3a-f,k,l). The compounds 2a,h and 3a-e,j were found to have an appreciable activity against Gram-positive bacteria (Staphylococcus aureus and Bacillus) in vitro, some of them inhibited growth of pathogenic yeasts (Candida albicans) (3a,b) and filamentous fungi (3a-e,f).

Functionalized alkyl and aryl diselenides as antimicrobial and antiviral agents: synthesis and properties.

The different dialkyl and diaryl diselenides with carbamoyl and sulfamoyl moieties 2, 3, 5 and other substituents in the ortho position of benzene ring 4, 7, 8 as well as derivatives of 1,2,4-benzoselenadiazine (6) were designed as antiviral and antimicrobial agents and synthesized. Some of them, particularly 8a and 8b, were found in the antiviral assay in vitro to be strong inhibitors of cytopathic activity encephalomyocarditis virus (EMCV). The compound 4a and 8a were found to have a broad spectrum of acivity against bacteria, yeasts and pathogenic fungi in vitro.

Antifungal activity of 2-(4-chlorophenyl)-1,2-benzisoselenazol-3(2H)-one, the analog of Ebselen.

The antimicrobial activity of 8 selenoorganic compounds (3-benzisoselenazoles, 1-benzisoselenazolone oxide and 4-disaryl diselenides) was investigated. It was found that selenoorganic compounds from benzisoselenazolone group suppress growth of some fungi and bacteria. The growth of Saccharomyces cerevisiae sigma 127-8b and Candida albicans 258 strains was strongly inhibited by the 2-(4-chlorophenyl)-1,2-benzisoselenazol-3(2H)-one. Also Ebselen and 2-acetyl-1,2-benzisoselenazol-3(2H)-one caused strong inhibition of Saccharomyces cerevisiae sigma 127-8b growth but a lower effect was observed in assays with Candida sp. strains. Benzisoselenazolones were also found to have antibacterial activities. They significantly reduced the growth of Gram-negative Escherichia coli K-12 ROW and Gram-positive Staphylococcus aureus 209P (Oxford) bacteria strains.

Seleno-organic compounds as immunostimulants: an approach to the structure-activity relationship.

Our studies on the seleno-organic compounds were focused at their activities as the modest cytokine inducers in human peripheral blood leukocyte cultures. Our bioassays used in the screening methods were based on the quantitative determinations of mainly two types of cytokines: interferons (IFNs) and tumor necrosis factors (TNFs). More recently we have found that several of the compounds have direct immunotropic actions in vitro and in vivo, in mice and in chickens. The paper summarizes the data related to the cytokine-inducing activity of 65 seleno-organic compounds divided into 4 groups according to their chemical structures. The reference compound was ebselen, the well known experimental drug with various biological activities. Approximately 50% of the compounds were found to be active in our bioassays. The selected compounds induced also IL-6 and GM-CSF. Their activities were clearly correlated with defined chemical structures as well as with the presence of selenium. We suggest that some of the selected by us compounds, other than ebselen, are interesting as immunostimulants and potential antiviral agents and cytokine inducers active in humans.

Effect of benzisoselenazolones and organic diselenides on graft versus host reaction and immunoglobulins levels in chickens.

Two week old chickens were treated once daily for 5 days with AE8--1-pyridyl-1,2-benzisoselenazol-3(2H)-one, AE22--bis-2-(N-phenyle-carboxamido) 1 pyridyl diselenide and AE31--bis(phenylo-diselenide with R3 = CONHC18H37). Their whole blood alone or blood mixed with thymus cells were used to generate graft versus host (GvH) reaction in 15 day old chicken embryos. The treatment of the chickens with the compounds stimulated the GvH reaction modifying activity of the donor cells as measured by increase of the spleen weight of the recipient chicken embryos. On the other hand, treatment with these compounds inhibited the IgG or IgM production in chickens immunized with human albumin.

Immunotropic activities of benzisoselenazolones and organic diselenides in mice.

We have investigated the immunotropic effects of 23 seleno-organic compounds (8 benzisoselenazolones, 3 benzisoselenazolone oxides and 12 organic diselenides). All of the compounds increased the rosette formation of sheep red blood cells (SRBC) with spleen cells obtained from thymectomized C53BL/6 mice and incubated in vitro in the presence of imuran. Furthermore, 16 of the compounds were also assayed in vitro in the hydrocortisone test performed with C57BL/6 mouse thymocytes. It was found that all of them significantly protected the cells against hydrocortisone induced cytotoxicity. Also in the Jerne's assay, performed in 129Ao/Boy mice pretreated in vivo with 3 selected compounds 5 days before immunization with SRBC, the stimulation of plaque forming cells (PFC) was observed. Only one compound (AE22, an analog of piroxicam) was found to be inhibitory in this assay. In contrast, in the graft versus host (GvH) assay performed in hybrid mice the donor lymphoid cells obtained from C57BL/6 mice pretreated with 9 selected seleno-organic compounds, suppressed the GvH reaction in the recipient hybrid mice. Thus, in all of the immunotropic assays except the GvH reaction in adult mice, the seleno-organic compounds were found to have immunostimulating activities.

Carboxyebselen a potent and selective inhibitor of endothelial nitric oxide synthase.

Ebselen (Ebs) a glutathione peroxidase like agent has been recently described as an inhibitor of nitric oxide synthase (NOS). Presently, we report that carboxyebselen (HOOC-Ebs), a hydrophyllic derivative of Ebs inhibits NOS present in enzymatic preparations from bovine endothelium, porcine cerebella, and murine spleen, however, it is both more potent and more selective for the constitutive endothelial NOS than Ebs. Unlike Ebs, HOOC-Ebs (0.1-30 microM) causes a concentration-dependent endothelium-independent relaxations of rings of rabbit aorta. The mechanism of this relaxation remains unknown and it is attenuated by glutathione (GSH, 30-300 microM) and N-acetyl-L-cysteine (NAC, 30-300 microM). The vasorelaxant activity of acetylcholine (Ach, 0.1-1 microM) in aortic rings exposed to low concentrations of HOOC-Ebs (0.1-1 microM) or rings exposed to 10 microM HOOC-Ebs after their pretreatment with GSH or NAC (30-300 microM) remained unchanged. The lack of activity of HOOC-Ebs as a NOS inhibitor in intact endothelial cells contrasts the effectiveness of Ebs in this respect.

Simultaneous induction of interferon gamma and tumor necrosis factor alpha by different seleno-organic compounds in human peripheral blood leukocytes.

Ebselen is known as anti-inflammatory and anti-oxidant selenium containing drug. We have synthetized 13 seleno-organic compounds, analogs of ebselen. Seven of them were found to be inducers of interferon gamma (IFN-gamma) and/or tumor necrosis factor alpha (TNF-alpha) in human peripheral blood leukocytes (PBL) cultures. The most active cytokine inducers were: 2-phenyl-1,2-benzisoselenazol-3(2H)-one (1, ebselen), bis [2-(N-phenylcarbamoyl)]phenyl diselenide (7) and bis (2-[N-(2-pyridyl)carbamoyl])phenyl diselenide (8). The amounts of IFN and TNF produced by PBL cultures in response to the seleno-organic compounds were found to be similar to that induced by phytohemagglutinin (PHA). The activities of the seleno-organic compounds were dose-dependent and related to the chemical structure of the drugs suggesting involvement of the specific cytokine-inducer receptor. The simultaneous inductions of IFN-gamma and TNF-alpha were highly correlated, but independent on each other.

Effects of some lipophilic carboxylic acid on release of interferon gamma from the human peripheral blood leukocytes.

Lipophilic carboxylic acids and their salts were tested for the ability of interferon induction in the cultures of human peripheral blood leukocytes. Of 13 tested organic compounds, two were selected: decyl-malonic acid and sodium salt of octylmethane-tri-(2-oxabutanoic)acid--which stimulated the synthesis of low amounts of gamma interferon.

Organoselenides as potential immunostimulants and inducers of interferon gamma and other cytokines in human peripheral blood leukocytes.

A number of organoselenium compounds have been described as anti-inflammatory, antioxidant, glutathione peroxidase-like agents and inhibitors of prostaglandin synthesis. Here we report that bis [2-(N-phenyl-carboxamido)]phenyl diselenide, 2-phenyl-1,2-benzisoselenazol-3(2H)-one (Ebselen) and related compounds are inducers of interferon gamma (IFN-gamma) and tumor necrosis factor (TNF) in human peripheral blood leukocytes. The IFN and TNF response was rapid, occurring within 20 h, and high--up to 1000 and 2000 units ml-1--and was clearly related to the dosage and the structure of the compounds. The action of the compounds and phytohemagglutinin was synergistic. The IFN gamma and TNF production was reduced after removing adherent cells. Although the mode of action of the compounds is not known, they appear to interact directly or indirectly with both adherent and non-adherent leukocytes, and stimulate the synthesis of a set of different cytokines including factors controlling the cell proliferation. Therefore, organoselenides may be regarded as the biological response modifiers.

Choline and halogen derivatives of CMA (9-oxo-10-acridine acetic acids) as tools for monitoring the interaction of the interferon inducers via a specific receptor.

New choline and halogen derivatives of CMA (9-oxo-10-acridine acetic acid) were investigated as interferon (IFN) inducers in mice and in the mouse bone marrow-derived macrophage cultures. Two of the choline derivatives, DMCMA and CSCMA, were active IFN inducers presumably because they were hydrolyzed so as to release CMA. The halogen analogues of CMA were inactive or weak IFN inducers in vivo and in vitro. On the contrary, the Br and I derivatives of CMA were potent inhibitors of IFN induction by CMA in vitro. The behavior of the agonists and antagonists of CMA suggests that the induction of interferon may occur indirectly via a specific CMA-receptor complex.

Induction of interferon in mice by sodium salt of 9-oxo-10-acridineacetic acid: specific enhancement by analogs.

9-oxo-10-acridineacetic acid bearing the common name of 10-carboxymethyl-9-acridanone or CMA (6) was found to be a very potent interferon (IFN) inducer in adult Balb/c mice. Seven structural analogs of CMA were synthetized and assayed for the interferon inducing ability. Three of the compounds had new chemical structures. The analogs were shown to be either weak or inactive interferon inducers. However, some of the analogs administered intraperitoneally (i.p.) or orally (p.o.) either 2 h before CMA or together with the active inducer enhanced by 10 to 60-fold the serum interferon response. We suggest that CMA induces interferon indirectly via a specific protein receptor. The specific enhancement of the serum interferon response to CMA by its inactive analogs may be explained in terms of the competition of the compounds for binding sites at the acceptor or transporting protein molecules. In the presence of an analog of CMA greater amount of free CMA may be available for the receptors in the target cells than when CMA acts alone. Only CMA bound to the receptor would be biologically active whereas the complexes of the compounds with the acceptor are biologically inert.

Interaction of sodium salt of 9-oxo-10-acridineacetic acid (CMA) and its analogs with serum albumin. A model for study on binding of the interferon inducer with receptor.

Equilibrium dialysis, gel filtration and SDS polyacrylamide gel electrophoresis were used to study the interaction of sodium salt of 9-oxo-10-acridineacetic acid (CMA) as well as its analogs 7, 8, 11, 13 - 16 with proteins. The compounds were found to bind mainly to serum albumins. Several other proteins had no affinity to the compounds. The close analogs 7 and 8 (sodium salt of 2,7-dibromo-9-oxo-10-acridineacetic acid and sodium salt of 9-oxo-10-acridinebutyric acid) which were inactive as interferon inducers were found to have greater affinity to bovine, mouse or human albumin than the active IFN inducer--CMA. The mechanism of interaction of CMA as well as its close analogs with albumin resembled the first phase of reaction of pharmacologically active ligands with their specific receptor or acceptor proteins. CMA and some of its close analogs were also shown to stabilize the human erythrocyte membrane against hemolysis in the hypotonic solution. However, the activity of the compounds was much weaker than that of other so called membrane active drugs.

Competition of sodium salt of 9-oxo-10-acridineacetic acid with analogs during induction of interferon in the mouse bone marrow-derived macrophages.

Analogs of 9-oxo-10-acridineacetic acid (CMA) including new synthetic compounds, were found to be valuable tools for investigating the mechanism of interferon (IFN) induction. Experiments were performed on the long-term cultures of mouse bone marrow-derived macrophages which are unusually susceptible to IFN induction by CMA. CMA in the optimal nontoxic concentration of 600 micrograms/ml may induce in the macrophages up to 3.500 units of IFN/ml. The response was found to be dose related. The analogs of CMA, compounds 3, 7-16, were found to be inactive as IFN inducers. However, the analogs 3, and 8-16 administered together with the suboptimal doses of CMA enhanced by 10 to 40-fold the interferon response to CMA. On the other hand, the compound 7 was shown to inhibit completely the induction of interferon by CMA. L-tryptophan was inactive as either enhancer or inhibitor of CMA. The mode of action of CMA is explained in terms of the hormonal concept of IFN induction.

[Introduction of a preventive dental care program in an aluminum plant]. / Doswiadczenia uzyskane przy wdrozeniu stomatologicznego programu profilaktycznego w hucie aluminium.

The paper presente experience acquired due to three years' oral prophylaxis programme designed for aluminum plant workers occupationally exposed to various hazards, particularly high concentrations of fluoride compounds. The programme covered oral health education, oral cavity irrigations and antidotum mouth-rinsing. The results indicate improvement of the dental health owing to the programme.