A Plant Proteinase Inhibitor from Enterolobium contortisiliquum Attenuates Pulmonary Mechanics, Inflammation and Remodeling Induced by Elastase in Mice

Abstract

Proteinase inhibitors have been associated with anti-inflammatory and antioxidant activities and may represent a potential therapeutic treatment for emphysema. Our aim was to evaluate the effects of a plant Kunitz proteinase inhibitor, Enterolobium contortisiliquum trypsin inhibitor (EcTI), on several aspects of experimental elastase-induced pulmonary inflammation in mice. C57/Bl6 mice were intratracheally administered elastase (ELA) or saline (SAL) and were treated intraperitoneally with EcTI (ELA-EcTI, SAL-EcTI) on days 1, 14 and 21. On day 28, pulmonary mechanics, exhaled nitric oxide (ENO) and number leucocytes in the bronchoalveolar lavage fluid (BALF) were evaluated. Subsequently, lung immunohistochemical staining was submitted to morphometry. EcTI treatment reduced responses of the mechanical respiratory system, number of cells in the BALF, and reduced tumor necrosis factor-α (TNF-α), matrix metalloproteinase-9 (MMP-9), matrix metalloproteinase-12 (MMP-12), tissue inhibitor of matrix metalloproteinase (TIMP-1), endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS)-positive cells and volume proportion of isoprostane, collagen and elastic fibers in the airways and alveolar walls compared with the ELA group. EcTI treatment reduced elastase induced pulmonary inflammation, remodeling, oxidative stress and mechanical alterations, suggesting that this inhibitor may be a potential therapeutic tool for chronic obstructive pulmonary disease (COPD) management.

The Plant Proteinase InhibitorCrataBLPlays a Role in Controlling Asthma Response in Mice

“…Slides containing tissue sections from the lungs were first deparaffinized and hydrated (Xylene 60°C Xylene 1, 2, and 3, first and second absolute ethanol, 96% ethanol, and 70% ethanol) followed by preparation with 3-aminopropyl triethoxysilane Silane (Sigma Aldrich, Missouri, USA). Slides were then washed with tap water and distilled water and subjected to the following procedures: antigen recovery; endogenous peroxidase blocking and nonspecific connections, incubation with primary antibody, incubation with secondary antibody, and peroxidase complex; visualization and counter-staining and mounting of slides [ 27 , 28 ].…”

“…We measured the fractional area of the bronchial wall (BW), blood vessel wall (BVW), and alveolar wall (AW) as the number of points that fell in either the BW, BVW, or AW divided by the total number of points that fell within the strip tissue. Measurements were performed in 10 fields per slide at 400× magnification, and we calculated the mean values for each animal [ 27 , 28 ].…”

“…This calculation was performed for each analyzed field. Area considered positive, according to the predetermined threshold color tones, was divided by the total area [ 27 , 28 ].…”

Efeitos do inibidor específico para serinoprotease rBmTI-A em modelo experimental de inflamação pulmonar alérgica crônica em camundongos Balb/c

“…Em modelos de doenças respiratórias, alguns inibidores de proteases foram testados e seus potenciais efeitos anti-inflamatórios nas vias aéreas foram demonstrados (Chen et al, 2006;Lin et al, 2014;Pigati et al, 2015;Martins-Olivera et al, 2016;Almeida-Reis et al, 2017;Theodoro-Junior et al, 2017 (Tanaka et al, 1999;Sasaki et al, 2004 (Lourenco et al, 2017).…”

“…Outro inibidor de serinoprotease, EcTI, além de atenuar a deposição de fibras colágenas e elásticas em modelo de enfisema pulmonar (Theodoro-Junior et al, 2017), também atuou no bloqueio da ativação de prometaloprotease-9 (proMMP-9) (Nakahata et al, 2011).…”