An insight into the antibiofilm properties of Costa Rican stingless bee honeys.

Objective: There is an increasing search for antibiofilm agents that either have specific activity against biofilms or may act in synergy with antimicrobials. Our objective is to examine the the antibiofilm properties of stingless bee honeys.

Method: Meliponini honeys from Costa Rica were examined along with Medihoney as a reference.

A proteinaceous fraction of wheat bran may interfere in the attachment of enterotoxigenic E. coli K88 (F4+) to porcine epithelial cells.

Wheat bran (WB) from Triticum aestivum has many beneficial effects on human health. To the best of our knowledge, very little has been published about its ability to prevent pathogenic bacterial adhesion in the intestine. Here, a WB extract was fractionated using different strategies, and the obtained fractions were tested in different in vitro methodologies to evaluate their interference in the attachment of enterotoxigenic Escherichia coli (ETEC) K88 to intestinal porcine epithelial cells (IPEC-J2) with the aim of identifying the putative anti-adhesive molecules.

New properties of wheat bran: anti-biofilm activity and interference with bacteria quorum-sensing systems.

Some plant extracts, have been demonstrated to interfere with the microbial metabolism of several pathogenic bacteria. Within this antimicrobial properties it has been described the potential to inhibit or destroy biofilms or to interfere in quorum-sensing (QS) systems. However, to our knowledge, no study exploring this potential of wheat-bran (WB) has been published.

An in vitro examination of the antioxidant and anti-inflammatory properties of buckwheat honey.

Objective: Hydroxyl radical and hypochlorite anion formed at the wound site from superoxide anion produced by activated polymorphonuclear neutrophils (PMNs) are considered important factors in impaired wound healing. Superoxide anion may also react with nitric oxide produced by macrophages to form peroxynitrite, a third strong oxidant that damages surrounding tissue. In order to select honey for use in wound-healing products, different samples were compared for their capacity to reduce levels of reactive oxygen species (ROS) in vitro.

Anti-inflammatory properties of a liposomal hydrogel with povidone-iodine (Repithel) for wound healing in vitro.

A liposomal hydrogel with 3% povidone-iodine (PVP-ILH, Repithel) has shown clinical benefit in settings where inflammation and/or reactive oxygen species are thought to impede wound healing (e.g., burns, chronic wounds and in smokers).

The natural prenylated flavone artelastin is an inhibitor of ROS and NO production.

Artelastin, a prenylated flavone previously isolated from Artocarpus elasticus, was evaluated for its effect on the production of reactive oxygen species (ROS) by human polymorphonuclear neutrophils (PMNs) and nitric oxide (NO) by J774 murine macrophage cell line. Artelastin showed to be an inhibitor of ROS production due to a strong O2- scavenging activity. No effect was observed on the activity of myeloperoxidase (MPO).

Complement-Inhibiting Constituents of Bridelia ferruginea Stem Bark.

A bioassay-guided fractionation of an 80% acetone extract from BRIDELIA FERRUGINEA stem bark showing a dose-dependent inhibitory effect towards both the classical and the alternative pathways of the complement system resulted in the isolation of a biflavanol (gallocatechin-(4'- O-7)-epigallocatechin) ( 1), 3,5-dicaffeoylquinic acid ( 2), 1,3,4,5-tetracaffeoylquinic acid ( 3), and a series of 3-methoxyflavone derivatives, including quercetin 3-methyl ether ( 4), quercetin 3,7,3',4'-tetramethyl ether ( 5), myricetin 3',4',5'-trimethyl ether ( 6; new compound) named ferrugin, myricetin 3,3',4',5'-tetramethyl ether ( 7), myricetin ( 8), and quercetin 3- O-glucoside ( 9) as the active constituents. Especially the biflavanol 1 and the caffeoyl esters of quinic acid 2 and 3 showed a strong inhibitory effect (IC (50) < 10 microM) on the classical pathway, compared to rosmarinic acid. Also on the alternative pathway, the biflavanol 1, the quinic acid derivatives 2 and 3, and some of the 3-methoxyflavones 5, 7 and 8 were more active than rosmarinic acid.

A novel formulation of metal ions and citric acid reduces reactive oxygen species in vitro.

Objective: Reactive oxygen species, including superoxide anions, are thought to play an important role in impairing wound healing. Additionally, superoxide anions react with nitric oxide produced by macrophages to form peroxynitrite, another strong oxidant with detrimental effects on surrounding tissue. This in vitro study investigated whether samples of metal ions and citric acid are able to reduce levels of reactive oxygen species.

Clionasterol: a potent inhibitor of complement component C1.

Clionasterol (1a), clionasterol monoacetate (1b) and 5alpha,8alpha-epidioxy-24alpha-ethylcholest-6-en-3-ol (2), isolated from the marine sponge Xestospongia exigua, and beta-sitosterol (3) were tested for their influence on the classical (CP) and alternative (AP) pathways of activation of the human complement system in vitro. All the sterols inhibited the CP in a dose-dependent manner but no detectable effect was observed in the AP even at concentrations of 400 microM. Clionasterol was found to be a potent inhibitor of CP (IC50 = 4.

Effects of methoxylation of apocynin and analogs on the inhibition of reactive oxygen species production by stimulated human neutrophils.

Owing to their multiple side effects, the use of steroidal drugs is becoming more and more controversial, resulting in an increasing need for new and safer anti-inflammatory agents. In the inflammatory process, reactive oxygen species produced by phagocytic cells are considered to play an important role. We showed that apocynin (4'-hydroxy-3'-methoxy-acetophenone or acetovanillone), a non-toxic compound isolated from the medicinal plant Picrorhiza kurroa, selectively inhibits reactive oxygen species production by activated human neutrophils.

Immunomodulatory and anti-inflammatory activity of Picrorhiza scrophulariiflora.

Extracts of the rhizomes of Picrorhiza scrophulariiflora Pennell (Scrophulariaceae) were investigated for their in vitro and in vivo immunomodulatory properties. Diethyl ether extracts showed potent inhibitory activity towards the classical pathway of the complement system, the respiratory burst of activated polymorphonuclear leukocytes, and mitogen-induced proliferation of T-lymphocytes. Furthermore, such extracts showed anti-inflammatory activity towards carrageenan-induced paw edema.

Inhibition of T-lymphocyte proliferation by cucurbitacins from Picrorhiza scrophulariaeflora.

Two cucurbitacin aglycons were isolated from the dried rhizomes of Picrorhiza scrophulariaeflora and were identified as 25-acetoxy-2,3, 16,20-tetrahydroxy-9-methyl-19-norlanosta-5,23-dien-22-one (picracin, 1) and 2,3,16,20,25-pentahydroxy-9-methyl-19-norlanosta-5, 23-dien-22-one (deacetylpicracin, 2). Both compounds inhibit mitogen-induced T-lymphocyte proliferation at an IC(50) value of 1 microM.

Apocynin inhibits peroxynitrite formation by murine macrophages.

Peroxynitrite (ONOO(-)) the highly reactive coupling product of nitric oxide and superoxide, has been implicated in the pathogenesis of an increasing number of (inflammatory) diseases. At present, however, selective peroxynitrite antagonizing agents with therapeutic potential are not available. Therefore, the NADPH-oxidase inhibitor apocynin (4-hydroxy-3-methoxy-acetophenone) was tested for its ability to inhibit peroxynitrite formation in vitro The murine macrophage cell-line J774A.

Apocynin, a plant-derived, cartilage-saving drug, might be useful in the treatment of rheumatoid arthritis.

Objective: To investigate whether apocynin, 1-(4-hydroxy-3-methoxyphenyl)ethanone, is able to diminish inflammation-induced cartilage destruction in rheumatoid arthritis (RA), studied in a human in vitro model.

Methods: Apocynin was added to cultures of RA peripheral blood mononuclear cells (PBMNC). Cartilage-destructive activity was determined by addition of culture supernatant to tissue samples of human articular cartilage.

Inhibition of human complement by beta-glycyrrhetinic acid.

Licorice, the root extract of Glycyrrhiza glabra I., is used as a medicine for various diseases. Anti-inflammatory as well as anti-allergic activities have been attributed to one of its main constituents, glycyrrhizin.

Podacycline A and B, two cyclic peptides in the latex of Jatropha podagrica.

Two novel cyclic peptides were isolated from the latex of Jatropha podagrica, which we named podacycline A and B. Podacycline A is a cyclic nonapeptide with the sequence Gly1-Leu2-Leu3-Gly4-Ala5-Val6-Trp7-Ala8-Gly9+ ++-Gly1. The sequence of podacycline B, a cyclic heptapeptide, was determined to be Phe1-Ala2-Gly3-Thr4-Ile5-Phe6-Gly7-Phe1.

Curcacycline A--a novel cyclic octapeptide isolated from the latex of Jatropha curcas L.

From the latex of Jatropha curcas L. (Euphorbiaceae) a novel cyclic octapeptide was isolated, which we named curcacycline A. The compound was found to contain one threonine, one valine, two glycine, and four leucine residues.

Trial and error in producing ankylosing-spondylitis-selective antisera according to Andrew Geczy.

Geczy found that rabbit sera raised against Klebsiella strain K43 cross-reacted with the cells from HLA-B27 positive patients with ankylosing spondylitis (AS). Other laboratories failed to reproduce these results. After a series of unsuccessful attempts, however, we managed to prepare one selective antiserum, using E.

Rabbit antisera to enterobacteriaceae isolated from HLA-B27 positive patients with ankylosing spondylitis (AS) are lytic for the mononuclear cells of AS patients.

Vaccines prepared from Gram-negative bacteria isolated from the stools of HLA-B27 positive AS patients were used to immunize rabbits. Three of the sera obtained were lytic in vitro for the mononuclear cells of HLA-B27 positive AS patients. One of these sera discriminated between AS patients and healthy HLA-B27 positive individuals.

House dust extracts contain potent immunological adjuvants.

A crude aqueous extract of house dust and two house dust subfractions were tested for adjuvant activity in a sensitivity assay performed in mice. Evidence is presented that house dust contains at least two potent immunological adjuvants. One of these, present in both subfractions, was probably endotoxin and acted in a complement-independent way.

A one-step isolation procedure for phospholipase A2-free cobra venom factor by fast protein liquid chromatography.

A very rapid and efficient procedure for isolation of cobra venom factor (CoF) from Naja naja venom is presented. The method is based on Mono Q anion exchange chromatography on a system for fast protein liquid chromatography (FPLC). CoF was eluted by a buffer of pH 7.

House dust allergen activates the classical complement pathway in mouse serum.

A house dust fraction was tested for complement activation in mouse serum using a microtitre complement fixation assay. It was observed that the preparation was a potent activator of the classical, but not of the alternative pathway suggesting an analogy with the complement activation in human serum. The activation showed similarity with that by classical complement activators such as aggregated IgG, DNA, lipopolysaccharide (LPS), but some discrepancy with mite allergen was observed.

A new, sensitive assay to determine immunological adjuvant activity based on the immunogenicity of neuraminidase-treated sheep erythrocytes.

A novel, sensitive system to determine immunological adjuvant activity is presented. It is based on the direct haemagglutinin response of mice to neuraminidase-treated sheep red blood cells (asialo-SRBC) seven days after i.p.