Chlorite-oxidized Oxyamylose Research Articles

Chlorite-Oxidized Oxyamylose (COAM) Has Antibacterial Activity and Positively Affects Skin Wound Healing.

PurposeTo verify the antibacterial and immunomodulatory effects of the amylose derivative – chlorite-oxidized oxyamylose (COAM) – in a skin wound setting.MethodsIn vitro antibacterial effects of COAM against opportunistic bacterial pathogens common to skin wounds, including Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA), were determined by cultivation methods. The effects of COAM on myeloid cell infiltration into full thickness skin wounds were investigated in wild-type and in transgenic CX3CR1-GFP mice.ResultsOn the basis of in vitro experiments, an antibacterial effect of COAM against Staphylococcus species including MRSA was confirmed. The minimum inhibitory concentration of COAM was determined as 2000 µg/mL against these bacterial strains. Control full thickness skin wounds yielded maximal neutrophil influxes and no additive effect on neutrophil influx was observed following topical COAM-treatment. However, COAM administration increased local CX3CR1 macrophage counts at days 3 and 4 and induced a trend towards better wound healing.ConclusionAside from its known broad antiviral impact, COAM possesses in vitro antibacterial effects specifically against Gram-positive opportunistic pathogens of the skin and modulates in vivo macrophage contents in mouse skin wounds.

Chlorite oxidized oxyamylose differentially influences the microstructure of fibrin and self assembling peptide hydrogels as well as dental pulp stem cell behavior

Tailored hydrogels mimicking the native extracellular environment could help overcome the high variability in outcomes within regenerative endodontics. This study aimed to evaluate the effect of the chemokine-binding and antimicrobial polymer, chlorite-oxidized oxyamylose (COAM), on the microstructural properties of fibrin and self-assembling peptide (SAP) hydrogels. A further goal was to assess the influence of the microstructural differences between the hydrogels on the in vitro behavior of human dental pulp stem cells (hDPSCs). Structural and mechanical characterization of the hydrogels with and without COAM was performed by atomic force microscopy and scanning electron microscopy to characterize their microstructure (roughness and fiber length, diameter, straightness, and alignment) and by nanoindentation to measure their stiffness (elastic modulus). Then, hDPSCs were encapsulated in hydrogels with and without COAM. Cell viability and circularity were determined using confocal microscopy, and proliferation was determined using DNA quantification. Inclusion of COAM did not alter the microstructure of the fibrin hydrogels at the fiber level while affecting the SAP hydrogel microstructure (homogeneity), leading to fiber aggregation. The stiffness of the SAP hydrogels was sevenfold higher than the fibrin hydrogels. The viability and attachment of hDPSCs were significantly higher in fibrin hydrogels than in SAP hydrogels. The DNA content was significantly affected by the hydrogel type and the presence of COAM. The microstructural stability after COAM inclusion and the favorable hDPSCs' response observed in fibrin hydrogels suggest this system as a promising carrier for COAM and application in endodontic regeneration.

Increase in Sialylation and Branching in the Mouse Serum N-glycome Correlates with Inflammation and Ovarian Tumour Progression

Ovarian cancer is the most lethal gynaecological cancer and is often diagnosed in late stage, often as the result of the unavailability of sufficiently sensitive biomarkers for early detection, tumour progression and tumour-associated inflammation. Glycosylation is the most common posttranslational modification of proteins; it is altered in cancer and therefore is a potential source of biomarkers. We investigated the quantitative and qualitative effects of anti-inflammatory (acetylsalicylic acid) and pro-inflammatory (thioglycolate and chlorite-oxidized oxyamylose) drugs on glycosylation in mouse cancer serum. A significant increase in sialylation and branching of glycans in mice treated with an inflammation-inducing compound was observed. Moreover, the increases in sialylation correlated with increased tumour sizes. Increases in sialylation and branching were consistent with increased expression of sialyltransferases and the branching enzyme MGAT5. Because the sialyltransferases are highly conserved among species, the described changes in the ovarian cancer mouse model are relevant to humans and serum N-glycome analysis for monitoring disease treatment and progression might be a useful biomarker.

Rescue from acute neuroinflammation by pharmacological chemokine-mediated deviation of leukocytes

BackgroundNeutrophil influx is an important sign of hyperacute neuroinflammation, whereas the entry of activated lymphocytes into the brain parenchyma is a hallmark of chronic inflammatory processes, as observed in multiple sclerosis (MS) and its animal models of experimental autoimmune encephalomyelitis (EAE). Clinically approved or experimental therapies for neuroinflammation act by blocking leukocyte penetration of the blood brain barrier. However, in view of unsatisfactory results and severe side effects, complementary therapies are needed. We have examined the effect of chlorite-oxidized oxyamylose (COAM), a potent antiviral polycarboxylic acid on EAE.MethodsEAE was induced in SJL/J mice by immunization with spinal cord homogenate (SCH) or in IFN-γ-deficient BALB/c (KO) mice with myelin oligodendrocyte glycoprotein peptide (MOG35-55). Mice were treated intraperitoneally (i.p.) with COAM or saline at different time points after immunization. Clinical disease and histopathology were compared between both groups. IFN expression was analyzed in COAM-treated MEF cell cultures and in sera and peritoneal fluids of COAM-treated animals by quantitative PCR, ELISA and a bioassay on L929 cells. Populations of immune cell subsets in the periphery and the central nervous system (CNS) were quantified at different stages of disease development by flow cytometry and differential cell count analysis. Expression levels of selected chemokine genes in the CNS were determined by quantitative PCR.ResultsWe discovered that COAM (2 mg i.p. per mouse on days 0 and 7) protects significantly against hyperacute SCH-induced EAE in SJL/J mice and MOG35-55-induced EAE in IFN-γ KO mice. COAM deviated leukocyte trafficking from the CNS into the periphery. In the CNS, COAM reduced four-fold the expression levels of the neutrophil CXC chemokines KC/CXCL1 and MIP-2/CXCL2. Whereas the effects of COAM on circulating blood and splenic leukocytes were limited, significant alterations were observed at the COAM injection site.ConclusionsThese results demonstrate novel actions of COAM as an anti-inflammatory agent with beneficial effects on EAE through cell deviation. Sequestration of leukocytes in the non-CNS periphery or draining of leukocytes out of the CNS with the use of the chemokine system may thus complement existing treatment options for acute and chronic neuroinflammatory diseases.

Glycosaminoglycan mimicry by COAM reduces melanoma growth through chemokine induction and function

Chlorite-oxidized oxyamylose (COAM), a glycosaminoglycan mimetic and potent antiviral agent, provided significant growth reduction of syngeneic murine B16-F1 melanoma tumors. A single early dose (100 μg, into the site of tumor cell inoculation) was sufficient to establish a persistent effect over 17 days (resected tumor volume of 78.3 mm(3) in COAM-treated mice compared to 755.2 mm(3) in the control cohort, i.e., 89.6% reduction of tumor volumes). COAM was a much better antitumoral agent than the polyanionic glycosaminoglycan heparin. COAM retained its antitumoral effect in lymphopenic mice, reinforcing the idea of myeloid cell involvement. Massive recruitment of myeloid cells into dermal air pouches in response to COAM and their increased presence in early-treated tumors indicated that mainly CD11b(+) GR-1(+) myeloid cells were attracted by COAM to exert antitumoral effects. Leukocyte chemotaxis was mediated by the chemokine system through the induction in B16-F1 cells of mouse granulocyte chemotactic protein-2/CXCL6 upon COAM treatment. Thus, COAM constitutes a novel tool to study the role of innate immune cells in the initial stages of tumor development and an example that innate immunostimulating glycosaminoglycan mimicry may be exploited therapeutically.

Virus entry inhibition by chlorite-oxidized oxyamylose versus induction of antiviral interferon by poly(I:C)

Unlike polyribonucleotides, such as poly(I:C), chlorite-oxidized oxyamylose (COAM) has been poorly characterized as a polyanionic antiviral. COAM possesses a controversial interferon (IFN)-inducing capacity and its mechanism of action has not been elucidated. In this study, COAM was biochemically characterized and fractionated according to molecular mass. In comparison with a strong IFN induction and upregulation of the helicase RIG-I and MDA-5 mRNAs by poly(I:C), COAM did not enhance IFN-α or -β and IFN-inducible RNA helicases in mouse fibroblastoid cells. Instead, COAM inhibited virus entry by blocking the attachment to the cells. These results suggest that COAM can alter the outcome of infection, not by IFN induction and in turn modifying the cellular antiviral state, but through inhibition of virus entry into cells.

Comparison of the effects of chlorite-oxidized oxyamylose and polyacrylic acid on the multiplication of phytopathogenic viruses

Polyacrylic acid (PAA) and chlorite-oxidized oxyamylose (COAM) inhibit the multiplication of tobacco mosaic virus (TMV) in leaf disks by up to 50%. The reduction in TMV content is time-dependent and decreases with longer time intervals between the virus infection and the application of substances. The multiplication of potato virus X (PVX) in leaf disks is not affected by either PAA or COAM. In intact plants PAA produces a strong antiviral effect on both PVX and red clover mottle virus (RCMV). The effect produced by COAM is much less pronounced, although this substance is less toxic and could be used in a higher concentration than PAA. Neither of these compounds has a significant influence on the development of virus-induced necroses in Nicotiana glutinosa, Gomphrena globosa or Phaseolus vulgaris plants when administered one day before or after virus infection.

Protection of mice against Babesia microti with cord factor, COAM, zymosan, glucan, Salmonella and Listeria.

Cord factor (trehalose 6-6' dimycolate). COAM (chlorite-oxidized oxyamylose), zymosan, glucan, Salmonella enteritidis 11RX and Listeria monocytogenes were found to protect mice against subsequent infection with Babesia microti, an intra-erythrocytic protozoan parasite. This protection was not observed after injection of Staphylococcus epidermidis, a viridans group Streptococcus, thioglycollate, or colloidal carbon. All the agents which protect against B. microti have also been reported to induce non-specific protection against experimental tumours. The parasites appear to die inside circulating red cells. This implies that these can exert non-specific protection against this parasite through the mediation of a soluble factor.

Use of Silica to Identify Host Mechanisms Involved in Suppression of Established Friend Virus Leukemia

Silica, an agent predominantly toxic for macrophages, inoculated i.v. to Friend leukemia virus (FLV)-infected mice, blocks the FLV-leukemosuppressive effects of chlorite-oxidized oxyamylose (COAM)-statolon treatment. FLV-infected, COAM-statolon-treated mice that have received silica and have failed to suppress FLV leukemia produced normal amounts of interferon, but did not make antibodies cytotoxic for FLV leukemic cells. Transfer of untreated spleen cells, splenic T cells, or thymocytes from mice with suppressed FLV erythroleukemia to FLV-infected mice treated with silica and COAM-statolon restores the humoral immune response to FLV antigens and results in leukemosuppression. Thus, T lymphocytes from mice with suppressed erythroleukemia participate in FLV leukemosuppression either directly as effector cells, or indirectly as helper cell in the production of antibodies to FLV antigens.

Intranasal Challenge of Mice with Herpes Simplex Vims: An Experimental Model for Evaluation of the Efficacy of Antiviral Drugs

An experimental model of herpetic infection based on intranasal challenge of 12-day-old mice with herpes simplex virus (type 1) has been developed for assessment of the efficacy of a variety of antiviral compounds with clinical potential: cytosine arabinoside, adenine arabinoside, iododeoxyuridine, ribavirin, chloriteoxidized oxyamylose, polyriboinosinic-polyribocytidylic acid, and interferon. The model employed is reminiscent of herpetic encephalitis in humans in both the portal of entry (nasopharyngeal cavity) and the mode of transmission (nerve route) of the virus to the target organ (brain). The mortality rate from viral infection was significantly reduced (greater than or equal to 30%) by the following treatment regimens: cytosine arabinoside, adenine arabinoside, iododeoxyuridine, and ribavirin, administered daily for seven consecutive days starting immediately after inoculation of virus, at dosage levels of 4-20 mg/kg, 20-100mg/kg, 100mg/kg, and 20-100 mg/kg, respectively; and chlorite-oxidized oxyamylose, polyriboinosinic-polyribocytidylic acid, and mouse interferon, administered 24 hr before viral challenge, as single doses of 100-500 mg/kg, 20mg/kg, and 10(7)-10(8) international reference units/kg respectively. Similar doses of polyriboinosinic-polyribocytidylic acid and mouse interferon administered after inoculation of virus did not alter the final mortality rate.

Suppression of extablished Friend virus leukemia by statolon: potentiation of statolon's leukemosuppressive activity by chlorite-oxidized oxyamylose

Treatment of Friend virus (FV)-infected mice, 3 days after FV inoculation, with statolon, an extract of the mold Penicillium stoloniferum, induces interferon and restores immunocompetence to viral and nonviral antigens such as sheep erythrocytes. Clinical remissions are established in 20 to 70% of the infected mice. Cholorite-oxidized oxyamylose administered intraperitoneally 24 h before, 3 h before, or 3 h after statolon enhanced interferon production, but the increased number of mice protected against FV disease was more closely related to the associated enhanced synthesis of FV cytotoxic antibody. The prolonged selective immunodepression to intraperitoneal sheep erythrocytes after intraperitoneal administration of chlorite-oxidized oxyamylose-statolon appeared to be related to a stimulation in number and erythrocyte-phagocytic capacity of peritoneal macrophages. The marked activation of macrophages in FV leukemic mice after such treatment may also have contributed to the enhanced FV leukemosuppressive effects of chlorite-oxidized oxyamylose-statolon.

Depression of Humoral Immunity to Sheep Erythrocytes in Vitro by Friend Virus Leukemic Spleen Cells: Induction of Resistance by Statolon

The in vitro antibody plaque-forming cell (PFC) response of normal spleen cells exposed to sheep erythrocytes in Marbrook chambers was depressed by the addition of Friend virus (FV) leukemic spleen cells. Fewer than 10-5 leukemic cells inhibited the PFC response of 10-7 normal cells. This immunodepression could not be produced with sonicated, irradiated, or mitomycin C-treated leukemic cells or with cellfree FV. It could be blocked by FV immune serum but was unaffected by high titers of purified interferon. Interferon did not inhibit the immune response of normal spleen cells to sheep erythrocytes. Spleen cells from mice treated with statolon or chlorite-oxidized oxyamylose statolon but not Newcastle disease virus or poly rI:poly rC were resistant to immunodepression in vitro by FV leukemic spleen cells. The unique ability of statolon to prevent immunodepression by leukemic spleen cells may be the basis of its FV leukemo-suppressive activity in vivo.

Increased toxicity of double-stranded ribonucleic acid in virus-infected animals.

Virus-infected mice were significantly more susceptible to the toxic effects of double-stranded ribonucleic acid (RNA) than uninfected mice. A dramatic increase in mortality was observed after injection of either synthetic (polyriboinosinic.polyribocytidylic acid) or natural (mycophage) double-stranded RNA in mice infected with Newcastle disease virus (NDV) or vesicular stomatitis virus (VSV). With the exception of endotoxin, interferon inducers other than double-stranded RNA, such as tilorone-hydrochloride and chlorite-oxidized oxyamylose, did not show this increased toxicity in virus-infected animals. The increased susceptibility of virus-infected animals to the toxic effects of double-stranded RNA appears to be related to the levels of interferon induced by the virus infection, either systemically, in the blood stream (after inoculation of NDV), or locally, in the brain (after infection with VSV).

Effect of chlorite-oxidized oxyamylose on Moloney sarcoma virus-induced tumor formation in mice

Chlorite-oxidized oxyamylose (COAM) effectively inhibited tumor growth in NMRI mice infected neonatally with the Moloney strain of murine sarcoma virus (M-MSV). This protective effect was most pronounced with single doses of the compound administered shortly before or after virus challenge. At the appropriate dosage level, COAM was also effective when it was administered as a single dose at 7 or 13 days after the virus or when it was injected in repeated doses on alternate days from 7 till 19 days or from 13 till 23 days after virus challenge. COAM reduced both tumor incidence and death due to tumor growth. However, with the treatment regimens used, it did not cause a regression of tumors which had already appeared at the time treatment was initiated.

Interferon Production Linked to Toxicity of Polyriboinosinic Acid-Polyribocytidylic Acid

Different procedures have been used in attempts to increase the production of interferon by polyriboinosinic acid-polyribocytidylic acid (poly [rI].poly [rC]) in mice: simultaneous injection of lead acetate, cycloheximide, or actinomycin D and prior injection of Freund's adjuvant, chlorite-oxidized oxyamylose (COAM), endotoxin, or Brucella abortus. In the experimental conditions tested, lead acetate, cycloheximide, Freund's adjuvant, and COAM brought about a parallel increase in interferon production and toxicity (lethality) of poly (rI).poly (rC); actinomycin D, endotoxin, and B. abortus increased the lethality of poly (rI).poly (rC) without a concomitant raise of its interferon-inducing capacity. Our results indicate that no significant increase in interferon production (or antiviral activity, as far as the antiviral activity is accounted for by interferon production) without an accompanying increase in toxicity can be achieved with poly (rI).poly (rC) and that it might be impossible to increase its therapeutic ratio (ratio of maximum tolerated dose to minimum effective dose).

Effect of Chlorite-Oxidized Oxyamylose on Influenza Virus Infection in Mice

Intraperitoneally administered chlorite-oxidized oxyamylose (COAM) provided protection of mice against intranasal infection with several influenza virus strains. Treated animals invariably showed a reduced consolidation of the lungs and, in the case of infection with lethal strains of virus, also a delay in mortality. With a small dose of influenza A/PR8 virus, an increase in final survival rate could be observed. The effect of COAM on influenza virus infection lasted for at least 4 to 8 days. Inhibition of lung consolidation was not paralleled by a decrease in virus multiplication in the lung. The significance of this finding in relation to the mechanism of the antiviral action of COAM is discussed.

Effects of oxyamylose and polyacrylic acid on foot-and-mouth disease and hog cholera virus infections.

Two interferon-inducing polycarboxylates were tested for antiviral activity on foot-and-mouth disease (FMD) virus infections in mice, guinea pigs, and swine. Polyacrylic acid, given intraperitoneally, had a protective effect on infection by FMD virus administered in the peritoneal cavity of mice and in the foot pad of guinea pigs. Chlorite-oxidized oxyamylose (COAM) was effective in mice at a dosage of 2 mg/kg. Swine were not protected against naturally transmitted FMD by 120 mg/kg of COAM nor by polyacrylic acid. Swine were not totally unresponsive to COAM since it delayed symptoms of hog cholera. Interferon was not detected in the serum of COAM-treated swine. With FMD virus, an example was found of activity of interferon inducers in experimental hosts and lack of activity in a natural host.

Effects of Oxyamylose and Polyacrylic Acid on Foot-and-Mouth Disease and Hog Cholera Virus Infections

Two interferon-inducing polycarboxylates were tested for antiviral activity on foot-and-mouth disease (FMD) virus infections in mice, guinea pigs, and swine. Polyacrylic acid, given intraperitoneally, had a protective effect on infection by FMD virus administered in the peritoneal cavity of mice and in the foot pad of guinea pigs. Chlorite-oxidized oxyamylose (COAM) was effective in mice at a dosage of 2 mg/kg. Swine were not protected against naturally transmitted FMD by 120 mg/kg of COAM nor by polyacrylic acid. Swine were not totally unresponsive to COAM since it delayed symptoms of hog cholera. Interferon was not detected in the serum of COAM-treated swine. With FMD virus, an example was found of activity of interferon inducers in experimental hosts and lack of activity in a natural host.

Effect of Chlorite-Oxidized Oxyamylose on Influenza Virus Infection in Mice

Intraperitoneally administered chlorite-oxidized oxyamylose (COAM) provided protection of mice against intranasal infection with several influenza virus strains. Treated animals invariably showed a reduced consolidation of the lungs and, in the case of infection with lethal strains of virus, also a delay in mortality. With a small dose of influenza A/PR8 virus, an increase in final survival rate could be observed. The effect of COAM on influenza virus infection lasted for at least 4 to 8 days. Inhibition of lung consolidation was not paralleled by a decrease in virus multiplication in the lung. The significance of this finding in relation to the mechanism of the antiviral action of COAM is discussed.

Antiviral activity of chlorite-oxidized oxyamylose, a polyacetal carboxylic acid.

Intraperitoneal injection of chlorite-oxidized oxyamylose (COAM) protected mice against mengo, vaccinia, Semliki Forest, and influenza APR8 viruses. Topical administration in the eye of rabbits partially inhibited the development of experimental herpetic keratoconjunctivitis. COAM resembled polyacrylic acid in many aspects, but it was markedly less toxic. For systemic administration, the therapeutic index was on the order of magnitude of 1:300 to 1:500. Although the in vivo antiviral effect of COAM wore off faster than that of polyacrylic acid, protection lasted for several weeks. Against mengovirus, such prolonged protection was achieved only when polymer and virus were injected intraperitoneally. Protection against intravenous vaccinia virus was not dependent on the injection route of COAM. Experiments on the mode of action of COAM pointed to macrophages as possible mediators of the antiviral effect. The fact that small amounts of interferon appeared in the serum after administration of high doses of COAM suggests that interferon may play a role in the induction of antiviral resistance by COAM.