Virus inactivation under the photodynamic effect of phthalocyanine zinc(II) complexes.

Various metal phthalocyanines have been studied for their capacity for photodynamic effects on viruses. Two newly synthesized water-soluble phthalocyanine Zn(II) complexes with different charges, cationic methylpyridyloxy-substituted Zn(II)- phthalocyanine (ZnPcMe) and anionic sulfophenoxy-substituted Zn(II)-phthalocyanine (ZnPcS), were used for photoinactivation of two DNA-containing enveloped viruses (herpes simplex virus type 1 and vaccinia virus), two RNA-containing enveloped viruses (bovine viral diarrhea virus and Newcastle disease virus) and two nude viruses (the enterovirus Coxsackie B1, a RNA-containing virus, and human adenovirus 5, a DNA virus). These two differently charged phthalocyanine complexes showed an identical marked virucidal effect against herpes simplex virus type 1, which was one and the same at an irradiation lasting 5 or 20 min (Δlog=3.0 and 4.0, respectively). Towards vaccinia virus this effect was lower, Δlog=1.8 under the effect of ZnPcMe and 2.0 for ZnPcS. Bovine viral diarrhea virus manifested a moderate sensitivity to ZnPcMe (Δlog=1.8) and a pronounced one to ZnPcS at 5- and 20-min irradiation (Δlog=5.8 and 5.3, respectively). The complexes were unable to inactivate Newcastle disease virus, Coxsackievirus B1 and human adenovirus type 5.

Toll-like receptor-mediated anti-inflammatory action of glaucine and oxoglaucine.

Two isochinoline alkaloids, glaucine and oxoglaucine were investigated for their suggested anti-inflammatory influence concerning nitric oxide and cytokine production. Mouse peritoneal macrophages were stimulated with different Toll-like receptor (TLR) ligands such as LPS for TLR4, zymosan for TLR2 and CpG for TLR9. The alkaloids inhibited TNF-alpha and IL-6 production induced by these ligands. In regard to IL-12 suppressive effect was registered in the case of CpG stimulation. Glaucine succeeded to enhance LPS and zymosan-induced IL-10 production. The reduction of pro-inflammatory cytokines and increase of anti-inflammatory IL-10 are indicative for their use in different acute and chronic inflammatory diseases.

Effect of Candida albicans dsDNA in gastrointestinal Candida infection.

Neonates are highly sensitive to infections because they are biased to develop Th2 immune responses. When exposed to certain agents, such as DNA vaccines or CpG DNA motifs, neonates are capable to mount adult-like Th1 protective responses. This study investigates the capacity of Candida albicans (C. albicans) dsDNA to induce host resistance in newborn mice against gastrointestinal C. albicans infection. The protective properties of dsDNA are related to an increased number of spleen CD4+ T cells secreting IFN-gamma. In infected DNA-treated mice, an enhanced production of IFN-gamma by Peyer's patch cells was observed together with reduced colonization and histopathological changes in the stomach. Our results indicated that C. albicans dsDNA administration in neonates elicited the protective immune response against gastrointestinal Candida infection.

Inflammatory response in patients with active and inactive osteoarthritis.

In the present study, we have investigated comparatively the inflammatory response of patients with active and inactive osteoarthritis. The sera from 31 healthy individuals, 37 patients with active OA, and 19 patients with inactive OA were assayed for TNF-alpha, IL-6, sRANKL, RANTES, and MRP8 using ELISA in order to evaluate their potential as markers of disease activity. Also, the spontaneous and LSP-induced release of TNF-alpha and IL-6 by peripheral blood neutrophils was determined. The activation of OA is associated with elevated TNF-alpha, IL-6, and RANTES serum levels while sRANKL and MRP8 appeared to be increased in both active and inactive OA. The neutrophil spontaneous and up-regulated by LPS cytokine release can contribute to the exacerbation of OA.

Anti-herpesvirus activities of Pseudomonas sp. S-17 rhamnolipid and its complex with alginate.

The rhamnolipid biosurfactant PS-17 and its complex with the polysaccharide alginate, both produced by the Pseudomonas sp. S-17 strain, were studied for their antiviral activity against herpes simplex virus (HSV) types 1 and 2. They significantly inhibited the herpesvirus cytopathic effect (CPE) in the Madin-Darby bovine kidney (MDBK) cell line. The investigations were carried out according to the CPE inhibition assay protocol. The suppressive effect of the compounds on HSV replication was dose-dependent and occurred at concentrations lower than the critical micelle concentration of the surfactant. The 50% inhibitory concentration (IC50) of rhamnolipid PS-17 was 14.5 microg/ml against HSV-1 and 13 microg/ml against HSV-2. The IC50 values of the complex were 435 microg/ml for HSV-1 and 482 microg/ml for HSV-2. The inhibitory effects of the substances were confirmed by measuring the infectious virus yields with the multicycle virus growth experimental design as well: deltalog CCID50 of 1.84-2.0 against the two types of herpes simplex viruses by rhamnolipid PS-17 (20 microg/ml), and a strong reduction of the HSV-2 virus yield under the effect of the alginate complex at a concentration of 450 microg/ml. The results indicate that rhamnolipid PS-17 and its alginate complex may be considered as promising substances for the development of anti-herpetic compounds.

Proteinase inhibitors from Streptomyces with antiviral activity.

An extensive screening study for the production of proteolytic inhibitors has been carried out on 75 Streptomyces strains. It was found that 18 of the strains and/or their variants (24%) produced proteinaceous substances, which belonged to the group of typical serine protease inhibitors. 23 samples were tested for inhibitory activity on the replication of influenza virus A/Germany/34, strain Rostock (H7N1) (A/Rostock) in chicken embryonic fibroblast (CEF) cells. Eleven of the tested samples (52.2%) significantly inhibited viral growth. Further the specific inhibitory effect on the replication of influenza virus A/Aichi/2/68 (H3N2) (A/Aichi) in Madin-Darby canine kidney (MDCK) cells and on the growth of herpes simplex virus type 1, strain DA (HSV-1) in Madin-Darby bovine kidney (MDBK) cells was tested. Nine samples significantly inhibited A/Aichi and four - HSV-1. The most effective inhibitors, produced by Streptomyces sp. 225b (SS 225b) and Streptomyces chromofuscus 34-1 (SS 34-1) protected mice from mortality in the experimental influenza A/Aichi virus infection.

Synergistic combination effect of cidofovir and idoxuridine on vaccinia virus replication.

In view of the potential menace of a terrorism attack with smallpox virus, an intensive search of chemotherapeutic agents active against orthopoxviruses is underway. We comparatively studied the antiviral activity of cidofovir (CDV) and idoxuridine (IUdR) against two vaccinia virus (VV) strains, Bratislava and RIIPD, in cell cultures of chick embryo fibroblasts (CEF). The investigations were carried out according to cytopathic effect (CPE) inhibition assay protocols. To determine the cytotoxicity of the compounds, maximal tolerated concentration (MTC) was calculated in CEF cell monolayers and 50% cell growth inhibitory concentration (CGIC50) was calculated in growing cell cultures. It was found that the antiviral effects were strongly dependent on virus inoculum size. There were no marked differences in the susceptibility to CDV and IUdR between the two VV strains. The individual half maximal inhibitory concentration (IC50) for CDV varied from 7.1-8.5 microM at 10/100 virus 50% infectious dose (ID50) to 13.6-26.5 microM at 10,000 ID50. The CDV selectivity index was also virus dose-dependent with MTC/IC50 and CGIC50/IC50 values ranging between 37.8-141.4 and 33.3-124.6, respectively. For IUdR, IC50 ranged from 0.58 to 0.85 microM, but the selectivity index for monolayer CEF and growing cell cultures produced substantial different results with MTC/IC50 and CGIC50/IC50 values between 117.7-172.4 and 20.4-33.3, respectively. The combination effects of CDV and IUdR against VV Bratislava strain in the CPE inhibition test were also determined. The test design of both combination antiviral effect and combined cytotoxicity followed a three-dimensional model. The combined effect of CDV and IUdR on VV replication in monolayer CEF cultures was characterized as a markedly synergistic one. In contrast, CDV and IUdR together reduced cytotoxicity in both monolayer and growing CEF cells.