Synergistic antibacterial and anti-inflammatory activity of temporin A and modified temporin B in vivo

Temporins are antimicrobial peptides secreted by the granular glands of the European red frog (Rana temporaria). They are 10-14 amino acid long polypeptides active prevalently against gram positive bacteria. This study shows that a synthetic temporin B analogue (TB-YK), acquires the capacity to act in synergism with temporin A and to exert antimicrobial and anti-inflammatory activity in vivo against gram positive and gram negative bacteria. Administration of 3.4 mg/Kg of temporin A (TA)+1.6 mg/Kg TB-YK, given to individual mice concurrently with a lethal dose of bacteria (gram positive or negative), rescued 100% of the animals. More importantly, the same doses of temporins, administered one week after experimental infection with a sub lethal dose of bacteria, sterilized 100% of the animals within 3-6 days. Also, it is described an animal model based on the use of sub lethal doses of bacteria, which closely mimics bacterial infection in humans. The model offers the possibility to test in a preclinical setting the true potential of TA and TB-YK in combination as antimicrobial and anti-inflammatory agents

New perspectives for natural antimicrobial peptides: application as antinflammatory drugs in a murine model.

Background: Antimicrobial peptides (AMPs) are an ancient group of defense molecules. AMPs are widely distributed in nature (being present in mammals, birds, amphibians, insects, plants, and microorganisms). They display bactericidal as well as immunomodulatory properties. The aim of this study was to investigate the antimicrobial and anti-inflammatory activities of a combination of two AMPs (temporin B and the royal jellein I) against Staphylococcus epidermidis. Results: The temporin B (TB-KK) and the royal jelleins I, II, III chemically modified at the C terminal (RJI-C, RJII-C, RJIII-C), were tested for their activity against 10 different Staphylococcus epidermidis strains, alone and in combination. Of the three royal jelleins, RJI-C showed the highest activity. Moreover, the combination of RJI-C and TB-KK (MIX) displayed synergistic activity. In vitro, the MIX displayed low hemolytic activity, no NO2- production and the ability to curb the synthesis of the pro-inflammatory cytokines TNF-alpha and IFN-gamma to the same extent as acetylsalicylic acid. In vivo, the MIX sterilized mice infected with Staphylococcus epidermidis in eleven days and inhibited the expression of genes encoding the prostaglandin-endoperoxide synthase 2 (COX-2) and CD64, two important parameters of inflammation. Conclusion: The study shows that the MIX - a combination of two naturally occurring peptides - displays both antimicrobial and anti-inflammatory activities

In vitro intestinal epithelium responses to titanium dioxide nanoparticles

Titanium dioxide (TiO2) is enclosed in many consumer products including pharmaceuticals, cosmetics, and foods. TiO2 (E171) is daily ingested as mixed nano- and submicron-sized particles since it is approved as a white colorant in Europe in a wide variety of food products, Noteworthy, the relevant risk assessment has never been satisfactorily concluded and growing alarms for human hazards deriving from TiO2 exposure are incrementally reported. The objective of the present study was to establish conceivable mechanisms by which nano-sized TiO2 particles affect physiological function of the intestinal epithelium layer. The well-established Caco-2 cell line differentiated for 21 days on permeable supports was used as a predictive model of the human intestinal mucosa to identify the biological response triggered by TiO2 particles. Exposure to 42 μg/mL TiO2 nanoparticles disrupted the tight junctions-permeability barrier with a prompt effect detectable after 4 h incubation time and wide effects on barrier integrity at 24 h. Transport and ultrastructural localization of TiO2 nanoparticles were determined by ICP-OES, TEM and ESI/EELS analysis, respectively. Nano-sized particles were efficiently internalized and preferentially entrapped by Caco-2 monolayers. Storage of TiO2 nanoparticles inside the cells affected enterocytes viability and triggered the production of pro-inflammatory cytokines, including TNF-α and IL-8. Taken together these data indicate that nano-sized TiO2 particles exert detrimental effects on the intestinal epithelium layer

Lactoferrin adsorbed onto biomimetic hydroxyapatite nanocrystals controlling - In vivo - The Helicobacter pylori infection

The resistance of Helicobacter pylori to the antibiotic therapy poses the problem to discover new therapeutic approaches. Recently it has been stated that antibacterial, immunomodulatory, and antioxidant properties of lactoferrin are increased when this protein is surface-linked to biomimetic hydroxyapatite nanocrystals.Based on these knowledge, the aim of the study was to investigate the efficacy of lactoferrin delivered by biomimetic hydroxyapatite nanoparticles with cell free supernatant from probiotic Lactobacillus paracasei as an alternative therapy against Helicobacter pylori infection.Antibacterial and antinflammatory properties, humoral antibody induction, histopathological analysis and absence of side effects were evaluated in both in vitro and in vivo studies.The tests carried out have been demonstrated better performance of lactoferrin delivered by biomimetic hydroxyapatite nanoparticles combined with cell free supernatant from probiotic Lactobacillus paracasei compared to both lactoferrin and probiotic alone or pooled.These findings indicate the effectiveness and safety of our proposed therapy as alternative treatment for Helicobacter pylori infection

Temporins are effective in vivo when given 7 days after experimental infection.

<p>Mice were infected with a sub-lethal dose (10⁵ CFU/mouse) of <i>S.aureus</i> A170 (A) or a sub-lethal dose(10⁵ CFU/mouse) of <i>S.enterica</i> serovar Paratyphi B (B–C) and 6 days later were treated with the 35/75 pool of temporins. A: kidneys from mice infected with <i>S.aureus</i> A170 (closed box) and kidneys from mice infected with <i>S.aureus</i> A170 and treated after 6 days with TA plus TB-YK (open rhomb); B: gastro instestinal tract from mice infected with <i>S.enterica</i> serovar Paratyphi B (closed box ) and gastro intestinal tract from mice infected with <i>S.enterica</i> serovar Paratyphi B and treated after 6 days with TA plus TB-YK (open rhomb); C: liver from mice infected with <i>S.enterica</i> serovar Paratyphi B (10⁵ CFU/mouse) (closed box) and liver from mice infected with <i>S.enterica</i> serovar Paratyphi B (10⁵ CFU/mouse) and treated after 6 days with the TA plus TB-YK (open rhomb).</p