Oral microbe-host interactions: influence of ß-glucans on gene expression of inflammatory cytokines and metabolome profile.

BACKGROUND: The aim of this study was to evaluate the effects of ß-glucan on the expression of inflammatory mediators and metabolomic profile of oral cells [keratinocytes (OBA-9) and fibroblasts (HGF-1) in a dual-chamber model] infected by Aggregatibacter actinomycetemcomitans. The periodontopathogen was applied and allowed to cross the top layer of cells (OBA-9) to reach the bottom layer of cells (HGF-1) and induce the synthesis of immune factors and cytokines in the host cells. ß-glucan (10 µg/mL or 20 µg/mL) were added, and the transcriptional factors and metabolites produced were quantified in the remaining cell layers and supernatant. RESULTS: The relative expression of interleukin (IL)-1-α and IL-18 genes in HGF-1 decreased with 10 µg/mL or 20 µg/mL of ß-glucan, where as the expression of PTGS-2 decreased only with 10 µg/mL. The expression of IL-1-α increased with 20 µg/mL and that of IL-18 increased with 10 µg/mL in OBA-9; the expression of BCL 2, EP 300, and PTGS-2 decreased with the higher dose of ß-glucan. The production of the metabolite 4-aminobutyric acid presented lower concentrations under 20 µg/mL, whereas the concentrations of 2-deoxytetronic acid NIST and oxalic acid decreased at both concentrations used. Acetophenone, benzoic acid, and pinitol presented reduced concentrations only when treated with 10 µg/mL of ß-glucan. CONCLUSIONS: Treatment with ß-glucans positively modulated the immune response and production of metabolites.

The Effects of Topical Application of Polycal (a 2:98 (g/g) Mixture of Polycan and Calcium Gluconate) on Experimental Periodontitis and Alveolar Bone Loss in Rats.

The aim of this study was to observe whether Polycal has inhibitory activity on ligation-induced experimental periodontitis and related alveolar bone loss in rats following topical application to the gingival regions. One day after the ligation placements, Polycal (50, 25, and 12.5 mg/mL solutions at 200 µL/rat) was topically applied to the ligated gingival regions daily for 10 days. Changes in bodyweight, alveolar bone loss index, and total number of buccal gingival aerobic bacterial cells were monitored, and the anti-inflammatory effects were investigated via myeloperoxidase activity and levels of the pro-inflammatory cytokines IL-1ß and TNF-α. The activities of inducible nitric oxide synthase (iNOS) and lipid peroxidation (MDA) were also evaluated. Bacterial proliferation, periodontitis, and alveolar bone loss induced by ligature placements were significantly inhibited after 10 days of continuous topical application of Polycal. These results indicate that topical application of Polycal has a significant inhibitory effect on periodontitis and related alveolar bone loss in rats mediated by antibacterial, anti-inflammatory, and anti-oxidative activities.

Beta-glucan-loaded nanofiber dressing improves wound healing in diabetic mice.

The increased prevalence of chronic wounds requires novel treatment options. The aim of this study was to develop a beta-glucan (ßG)-loaded nanofiber wound dressing. Nanofibers were prepared using the needle-free Nanospider™ technology, an electrospinning method which enables the production of nanofibers at an industrial scale. The ßG was selected as active ingredient based on its confirmed wound healing potential in both animals and humans. Hydroxypropyl methylcellulose (HPMC) and polyethylene oxide (PEO) were included as copolymers. Rheological profiles of spinning solutions containing HPMC, PEO, ßG, ethanol and water, were optimized. The nanofiber formation was confirmed by Field Emission Scanning Electron Microscopy (FE-SEM), and both nanofibers with (ßG-nanofibers) or without ßG (NoßG-nanofibers) were evaluated by their swelling index and FT-IR spectroscopy. The formulations, active ingredient and excipients were tested for their possible in vitro toxicity in keratinocytes. Finally, the wound healing potential of the nanofibers was tested in externally induced excisional wounds in male diabetic db/db mice. Three different doses of ßG-nanofibers and the ßG-free, NoßG-nanofibers, were evaluated for their in vivo wound healing efficacy. All nanofiber-treatments provided improved wound healing as compared to the negative control (water). All ßG-nanofiber treated groups exhibited significantly improved wound healing as compared to the NoßG-nanofiber treated group, indicating the potential of ßG-nanofibers as wound dressing.

[Effect of anthelmintic therapy supplemented with glucan in experimental toxocarosis]. / Efekt terapii przeciwrobaczej wspomaganej glukanem w doswiadczalnej toksokarozie.

The studies demonstrated high larvicidal efficiacy of the combined liposomal anthelmintic therapy supplemented with liposomal (beta-glucan) wchich acted as immunomodulator on the immune system of the infected animals. Therapeutic effect was very high in the treatment of hepatopneumonic toxocarosis as well as in cerebromuscular infection, reaching 94.3 and 89.3 % in the liver, 89.8 and 92.4 % in the lungs, 88.7 and 91.5 % in the muscles, and 91.5 and 90.5 % in the brain, respectively. It should be emphasized that although both anthelmintic combinations had high larvicidal efficacy, the combination 1(DEC+FUBZ+L) was more efficacious in the muscles, while 1(DEC+ABZ+L) was more efficient in the brain, independently of whether the treatment was implemented on 7th day after infection or on 47th infection day. It did not exceed the dose of one of these drugs used in monotherapy, whose larvicidal efficacy was always 2 or 3 times lower. Animals well tolerated the drug doses throughout the whole experimental period.

Early immune responses in Atlantic salmon (Salmo salar L.) after immunization with PLGA nanoparticles loaded with a model antigen and ß-glucan.

Polymeric nanoparticles (NPs) of poly (lactic-co-glycolic) acid (PLGA) possess adjuvant properties. To date, there are few studies exploring their application as antigen carriers for vaccination of fish. This study presents a preclinical assessment of the early innate and adaptive immune responses in Atlantic salmon following immunization with PLGA NPs. A model antigen (TNP-LPH) and an immunostimulant (ß-glucan) were entrapped in NPs of 300-400nm either alone or in combination. Both the antigen and the ß-glucan were efficiently entrapped (>50%) in particles and an antigen release study indicated particle stability up to 50 days at 8°C. Spleen and head kidney were analyzed for pro-inflammatory markers (TNF-α, IL-1ß, IL-8, C3a) and T cell cytokines, effector molecules and transcription factors (IFN-γ, T-bet, GATA-3, granzyme A, IL-10, Foxp3) at mRNA transcription levels 2, 4 and 8 days post i.p. immunization. NPs alone were able to moderately up-regulate pro-inflammatory immune responses. Addition of immunogenic cargo, either an antigen or ß-glucan generally increased the gene expression of pro-inflammatory markers, while administering both resulted in the highest gene expression. These findings were also reflected by concurrently increased levels of IL-10. Comparing the treatment groups injected with antigen and ß-glucan co-administered either in NPs or FCA demonstrated that the magnitude of the acute pro-inflammatory responses was equal between the treatments or highest in the NP injected group. Although elevated expression of granzyme A in the NP injected groups (carrying antigen and/or ß-glucan) was observed, PLGA NPs were unable to induce T cell differentiation on mRNA gene expression levels, as increased levels of the indicating cytokines and transcriptions factors failed to occur. In conclusion, this study demonstrates that PLGA NPs have potential as an adjuvant in salmon vaccines as they enhance the early pro-inflammatory responses to immunization.

Oral administration of beta-1,3/1,6-glucan to dogs temporally changes total and antigen-specific IgA and IgM.

The effect of oral administration of beta-1,3/1,6-glucans from Saccharomyces cerevisiae on humoral immunity in domestic dogs is not known. In this study, 15 beagle dogs were orally given MacroGard tablets, which contain 150 mg of this beta-glucan, daily for 4 weeks. At the end of this period, the total serum immunoglobulin A (IgA) level decreased significantly in the group treated with the glucan compared to that in the control group as well as compared to the concentrations before supplementation. In contrast, the total serum IgM level rose significantly, whereas no effect on the IgG level occurred. Similar changes were seen in Bordetella-specific IgA and IgM titers following vaccination during the supplementation period. The IgA concentration also became significantly lower in the saliva and tears of the glucan group than in the placebo group. The effects disappeared 1 week after the cessation of the supplementation. In conclusion, the results showed a temporary change in the isotype profile during glucan supplementation.

Controlled release biopolymers for enhancing the immune response.

Controlled release of biologically active compounds in the context of drug and vaccine delivery is an important area of research with broad implications in many areas of medicine. In particular, the challenges of oral delivery are of specific interest to reduce the cost and potential health risks related to parenteral administration of pharmaceuticals and vaccine formulations. We discuss the biological activities of two biopolymers, beta-glucans and emulsans, both of which offer significant potential for individual formulations related to drug impact, while in combination offer synergistic opportunities in terms of formulation and delivery. beta-Glucans have been established as potent immunomodulatory and biologically active compounds with application in a wide range of disease systems. The emulsan family of biopolymers also has significant potential in vaccine and drug delivery based on recent studies. Each of these biopolymers offers exciting opportunities to modulate biological responses via control of chemistry and physical properties achieved during biosynthesis or postsynthesis modifications. When combined into a delivery system for controlled release, synergistic outcomes may be achieved that offer new and exciting opportunities as described in the present paper. These outcomes represent the combined improvements of solubility in physiological environments and immunomodulation due to the specific chemistry and structures involved. Overall, this approach provides a new direction in controlled release wherein the biomaterial carrier, in this case emulsan, and the drug, in this case beta-glucan, play an active role both in biological activation as well as in delivery profiles.

Oral administration of a new soluble branched beta-1,3-D-glucan is well tolerated and can lead to increased salivary concentrations of immunoglobulin A in healthy volunteers.

The soluble branched yeast beta-1,3-D-glucan (SBG) belongs to a group of carbohydrate polymers known to exert potent immunomodulatory effects when administered to animals and humans. A new oral solution of SBG has been developed for local application to the oropharyngeal and oesophageal mucosa in order to strengthen the defence mechanisms against microbial and toxic influences. In the present study oral administration of SBG has been investigated primarily for assessment of safety and tolerability in an early phase human pharmacological study (phase I). Eighteen healthy volunteers were included among non-smoking individuals. The study was an open 1:1:1 dose-escalation safety study consisting of a screening visit, an administration period of 4 days and a follow-up period. Groups of six individuals received SBG 100 mg/day, 200 mg/day or 400 mg/day, respectively, for 4 consecutive days. The dose increase was allowed after a careful review of the safety data of the lower dose group. No drug-related adverse event, including abnormalities in vital signs, was observed. By inspection of the oral cavity only minor mucosal lesions not related to the study medication were seen in seven subjects. Repeated measurements of beta-glucan in serum revealed no systemic absorption of the agent following the oral doses of SBG. In saliva, the immunoglobulin A concentration increased significantly for the highest SBG dose employed. SBG was thus safe and well tolerated by healthy volunteers, when given orally once daily for 4 consecutive days at doses up to 400 mg.

Praziquantel and liposomized glucan-treatment modulated liver fibrogenesis and mastocytosis in mice infected with Mesocestoides vogae (M. corti, Cestoda) tetrathyridia.

Beta-glucans are immunomodulators able to activate innate immunity and to potentiate acquired immune reactions. We investigated the impact of co-administration of liposomized beta-glucan on the larvicidal effect of the anthelmintic praziquantel (PZQ) in the livers and peritoneal cavities in mice infected with Mesocestoides vogae (M. corti). Also, within 2 weeks following therapy (up to day 29 p.i.) we examined collagen synthesis in the livers of mice by means of biochemical determination of hydroxyproline concentration, total mast cell counts and cell proliferative capacity using immunohistochemical and radiometrical methods. After co-administration of liposomized glucan (LG) and PZQ efficacy (%) was significantly higher than after treatment with either compound alone, particularly in the peritoneal cavity compared to the liver. In comparison with the control, more intense collagenesis was found in the B-liver parts (high intensity of infection) and lowering of collagen content in the A-parts (very weak infection). This effect was strongest after LG treatment and co-administration of PZQ abolished the pro-fibrotic effect of LG. In all groups, mast cell counts were higher in the B-liver parts than in the A-parts and the dynamics of mastocytosis was profoundly modulated following therapy. Whereas the effect of PZQ was only moderate, early and very strong onset was seen after LG treatment. Administration of PZQ suppressed LG induced-elevation of mast cells counts in both liver parts. Using DNA S-phase markers (BrdU and 3H-thymidine) the proliferative capacity was shown to be associated with several kinds of liver cells. Therapy significantly stimulated [3H]-thymidine incorporation (cell proliferation) only in the A-parts over that in control, the most after LG administration. In summary (i) the anthelmintic effect of PZQ could be enhanced after simultaneous administration of the immunomodulator beta-glucan entrapped in a liposomal carrier, (ii) intense mastocytosis seen after treatment with LG seems to have a direct role in the glucan's pro-fibrotic activity and can be abolished after co-administration of PZQ in a time-dependent manner, (iii) the pattern of cell proliferation indicates that in the case of PZQ treatment, the reparative processes of liver parenchyma are enhanced in an inverse correlation with the intensity of infection.