melitten and Edema

Africanized Apis mellifera bees, also known as killer bees, have an exceptional defensive instinct, characterized by mass attacks that may cause envenomation or death. From the years 2000-2013, 77,066 bee accidents occurred in Brazil. Bee venom comprises several substances, including melittin and phospholipase A2 (PLA2). Due to the lack of antivenom for bee envenomation, this study aimed to produce human monoclonal antibody fragments (single chain fragment variable; scFv), by using phage display technology. These fragments targeted melittin and PLA2, the two major components of bee venom, to minimize their toxic effects in cases of mass envenomation. Two phage antibody selections were performed using purified melittin. As the commercial melittin is contaminated with PLA2, phages specific to PLA2 were also obtained during one of the selections. Specific clones for melittin and PLA2 were selected for the production of soluble scFvs, named here Afribumabs: prefix: afrib- (from Africanized bee); stem/suffix: -umab (fully human antibody). Afribumabs 1 and 2 were tested in in vitro and in vivo assays to assess their ability to inhibit the toxic actions of purified melittin, PLA2, and crude bee venom. Afribumabs reduced hemolysis caused by purified melittin and PLA2 and by crude venom in vitro and reduced edema formation in the paws of mice and prolonged the survival of venom-injected animals in vivo. These results demonstrate that Afribumabs may contribute to the production of the first non-heterologous antivenom treatment against bee envenomation. Such a treatment may overcome some of the difficulties associated with conventional immunotherapy techniques.

Topics: Animals; Antivenins; Bee Venoms; Cell Surface Display Techniques; Clone Cells; Drug Design; Drug Therapy, Combination; Edema; Hemolysis; Humans; Insect Bites and Stings; Insect Proteins; Male; Melitten; Mice; Phospholipase A2 Inhibitors; Phospholipases A2, Secretory; Recombinant Proteins; Single-Chain Antibodies; Subcutaneous Tissue; Survival Analysis

Peripheral modulation of wind-up enhancement induced by peripheral tissue injury is investigated in rat spinal wide-dynamic-range (WDR) neurons. After subcutaneous (s.c.) injection of melittin, a pain-related peptidergic component separated from bee venom, the responsiveness of spinal cord WDR neuron to repeated suprathreshold (1.5T, the intensity threshold) electrical stimuli is enhanced. Comparing with the less effects on early response (0-100 ms), melittin significantly increases late response (100 ms to the next stimulus artifact) and after-discharge (starting from 2s after the last stimulus artifact) with 189% and 546%, respectively. Peripheral administration of a specific MEK inhibitor, 1,4-diamino-2,3-dicyano-1,4-bis-[o-aminophenylmercapto] butadiene (U0126, 1 microg) gradually suppresses, but not completely blocks melittin-enhanced wind-up to the similar level of baseline. The inhibitions of U0126 are mainly on late response and after-discharge with 49% and 65%, respectively. Peripheral administration of three doses of U0126 (0.1, 1, 10 microg) has no effects on melittin-induced local paw edema regardless of either pre- or post-treatment of the drug. We conclude that peripheral ERKs pathway in the primary injury site is required to maintain melittin-enhanced wind-up of rat spinal cord wide-dynamic-range neurons.

Topics: Action Potentials; Analysis of Variance; Animals; Butadienes; Edema; Electric Stimulation; Enzyme Inhibitors; Foot; Male; MAP Kinase Signaling System; Melitten; Microelectrodes; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Neurons; Nitriles; Plethysmography; Rats; Rats, Sprague-Dawley; Spinal Cord; Time Factors

1 To investigate anti-inflammatory activity of organic germanium, we measured the effect of germanium-concentrated yeast on arachidonic acid release, prostaglandin E(2) (PGE(2)) production, histamine release, and intracellular H(2)O(2) or hydroperoxide generation in RBL 2H3 cells, and carrageenan-induced paw oedema in rats. 2 Germanium-concentrated yeast dose-dependently inhibited carrageenan-induced paw oedema, suggesting that germanium-concentrated yeast has anti-inflammatory activity in acute inflammation. 3 Germanium-concentrated yeast significantly inhibited melittin-induced arachidonic acid release and PGE(2) production in RBL 2H3 cells. 4 Germanium-concentrated yeast did not affect melittin-induced histamine release and silica-induced intracellular H(2)O(2) or hydroperoxide generation in RBL 2H3 cells. 5 These results suggest that anti-inflammatory activity of germanium-concentrated yeast appears partly to be related to the inhibition of arachidonic acid release and PGE(2) production in RBL 2H3 cells.

Topics: Administration, Oral; Animals; Anti-Inflammatory Agents; Arachidonic Acid; Carrageenan; Cell Line, Tumor; Dinoprostone; Dose-Response Relationship, Drug; Edema; Germanium; Mast Cells; Melitten; Organometallic Compounds; Rats; Yeasts

To investigate the molecular mechanisms of the antiarthritic effects of bee venom (BV) and melittin (a major component of BV) in a murine macrophage cell line (Raw 264.7) and in synoviocytes obtained from patients with rheumatoid arthritis.. We evaluated the antiarthritic effects of BV in a rat model of carrageenan-induced acute edema in the paw and in a rat model of chronic adjuvant-induced arthritis. The inhibitory effects of BV and melittin on inflammatory gene expression were measured by Western blotting, and the generation of prostaglandin E(2) (PGE(2)) and nitric oxide (NO) and the intracellular calcium level were assayed. NF-kappaB DNA binding and transcriptional activity were determined by gel mobility shift assay or by luciferase assay. Direct binding of BV and melittin to the p50 subunit of NF-kappaB was determined with a surface plasmon resonance analyzer.. BV (0.8 and 1.6 mug/kg) reduced the effects of carrageenan- and adjuvant-induced arthritis. This reducing effect was consistent with the inhibitory effects of BV (0.5, 1, and 5 mug/ml) and melittin (5 and 10 mug/ml) on lipopolysaccharide (LPS; 1 mug/ml)-induced expression of cyclooxygenase 2, cytosolic phospholipase A(2), inducible NO synthase, generation of PGE(2) and NO, and the intracellular calcium level. BV and melittin prevented LPS-induced transcriptional and DNA binding activity of NF-kappaB via the inhibition of IkappaB release and p50 translocation. BV (affinity [K(d)] = 4.6 x 10(-6)M) and melittin (K(d) = 1.2 x 10(-8)M) bound directly to p50.. Target inactivation of NF-kappaB by directly binding to the p50 subunit is an important mechanism of the antiarthritic effects of BV.

Topics: Animals; Arthritis; Arthritis, Experimental; Arthritis, Rheumatoid; Bee Venoms; Calcium; Carrageenan; Cell Line; Dinoprostone; Edema; Humans; Inflammation Mediators; Intracellular Membranes; Lipopolysaccharides; Luciferases; Macrophages; Male; Melitten; Mice; NF-kappa B; NF-kappa B p50 Subunit; Nitric Oxide; Rats; Rats, Sprague-Dawley; Synovial Membrane

Alminoprofen is a nonsteroidal anti-inflammatory drug (NSAID) of the phenylpropionic acid class. It has anti-inflammatory properties different from the classical NSAID. Using both in vitro systems of cells in culture and in vivo models of inflammation, we report here that alminoprofen possesses both antiphospholipase A2 (PLA2) activity and anti-cycloxygenase (COX) activity. The PLA2 targeted by alminoprofen is likely the secretory phospholipase A2 (sPLA2) while the COX targeted is the COX-2.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Cell Line; Cyclooxygenase 1; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cyclooxygenase Inhibitors; Dinoprostone; Edema; Flurbiprofen; Group II Phospholipases A2; Humans; Indans; Indomethacin; Isoenzymes; Melitten; Membrane Proteins; Phospholipases A; Phospholipases A2; Phospholipids; Propionates; Prostaglandin-Endoperoxide Synthases; Prostaglandins F; Rats; Rats, Wistar

Melittin (MLT) (10 micrograms/paw) and D49 (0.4 micrograms/paw) were injected into the hind paw of male CD-1 mice and elicited 70-80% of maximal paw edema responses at 60 and 30 min after injection, respectively. D49 paw edema was significantly inhibited by anti-histamine/serotonin agents, a PAF antagonist, a PLA2 inhibitor, and some but not all 5-LO and CO inhibitors, indicating that this edema is produced by several classes of inflammatory mediators with mast cell degranulation apparently playing a major role. In contrast, MLT paw edema was not inhibited effectively using the same pharmacological agents except theophylline, suggesting it was elicited via a different sequence of inflammatory events. In summary, D49 and MLT paw edema models were found to be ineffective models to identify experimental PLA2 compounds in our laboratory.

Topics: Animals; Anti-Inflammatory Agents; Cytoplasmic Granules; Disease Models, Animal; Edema; Foot; Histamine Antagonists; Male; Mast Cells; Melitten; Mice; Phospholipases A; Phospholipases A2