title: New properties of the soybean trypsin inhibitor: Inhibition of human neutrophil elastase and its effect on acute pulmonary injury.
abstract: Seeds from legumes including the Gilcine max are known to be a rich source of protease inhibitors. The soybean Kunitz trypsin inhibitors (SKTIs) have been well characterised and have been found to exhibit many biological activities. However their effects on inflammatory diseases have not been studied to date. In this study, SKTI was purified using anion exchange chromatography using a Resource Q column. The purified protein was able to inhibit human neutrophil elastase (HNE) and bovine trypsin. Purified SKTI inhibited HNE with an IC(50) value of 8mug or 0.3nM. At this concentration SKTI showed neither cytotoxic nor haemolytic effects on human blood cell populations. SKTI showed no deleterious effects on organs, blood cells or the hepatic enzymes ALT and AST in the mouse model of acute systemic toxicity. Human neutrophils incubated with SKTI released less HNE than control neutrophils when stimulated with PAF or fMLP (83.1% and 70% respectively). These results showed that SKTI affected both pathways of elastase release by PAF and fMLP stimuli, suggesting that SKTI is an antagonist of fMLP/PAF receptors. In an in vivo mouse model of LPS acute lung injury, SKTI significantly suppressed the inflammatory effects caused by elastase in a dose-dependent manner. Histological sections stained by hematoxylin/eosin confirmed this decrease in inflammation. These results showed that SKTI could be used as a pharmacological agent for the therapy of many inflammatory diseases.
authors.affiliation: Laboratório de Química e Função de Proteínas Bioativas, Departamento de Bioquímica, Centro de Biociências, Universidade Federal do Rio Grande do Norte 59072-970 Natal, RN, Brazil.
authors.forename: Jannison K C
authors.initials: JK
authors.lastname: Ribeiro
authors.forename: Dayse D S
authors.initials: DD
authors.lastname: Cunha
authors.forename: Jacy M S L L
authors.initials: JM
authors.lastname: Fook
authors.forename: Mauricio P
authors.initials: MP
authors.lastname: Sales
mesh_terms: D055371:Acute Lung Injury / Q000188:drug therapy* / Q000503:physiopathology; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000494:pharmacology* / Q000633:toxicity; D002417:Cattle; D002852:Chromatography, Ion Exchange / Q000379:methods; D004195:Disease Models, Animal; D006801:Humans; D007249:Inflammation / Q000188:drug therapy / Q000503:physiopathology; D020128:Inhibitory Concentration 50; D019272:Leukocyte Elastase / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D051379:Mice; D010980:Platelet Membrane Glycoproteins / Q000037:antagonists & inhibitors; D044042:Receptors, Formyl Peptide / Q000037:antagonists & inhibitors; D043562:Receptors, G-Protein-Coupled / Q000037:antagonists & inhibitors; D012639:Seeds; D013025:Glycine max / Q000737:chemistry; D023382:Toxicity Tests, Acute; D014357:Trypsin / Q000187:drug effects / Q000378:metabolism; D014360:Trypsin Inhibitor, Kunitz Soybean / Q000008:administration & dosage / Q000494:pharmacology* / Q000633:toxicity
chemical_list: D000893:Anti-Inflammatory Agents; D010980:Platelet Membrane Glycoproteins; D044042:Receptors, Formyl Peptide; D043562:Receptors, G-Protein-Coupled; C039351:platelet activating factor receptor; D014360:Trypsin Inhibitor, Kunitz Soybean; D019272:Leukocyte Elastase; D014357:Trypsin