Effects of plant protease inhibitors (Pep-3-EcTI, Pep-BbKI, and Pep-BrTI) versus corticosteroids on inflammation, remodeling, and oxidative stress in an asthma-COPD (ACO) model.

The peptide derived from E. contortisiliquum trypsin inhibitor (Pep-3-EcTI), peptide derived from kallikrein inhibitor isolated from B. bauhinioides (Pep-BbKI), and B. rufa peptide modified from B. bauhinioides (Pep-BrTI) peptides exhibit anti-inflammatory and antioxidant activities, suggesting their potential for treating asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO). We compared the effects of these peptides with dexamethasone (DX) treatment in an ACO model. In this study, 11 groups of male BALB/c mice were pre-treated under different conditions, including sensitization with intraperitoneal injection and inhalation of ovalbumin (OVA), intratracheal instillation of porcine pancreatic elastase (ELA), sensitization with intraperitoneal injection, and various combinations of peptide treatments with Pep-3-EcTI, Pep-BbKI, Pep-BrTI, dexamethasone, and non-treated controls (SAL-saline). Respiratory system resistance, airway resistance, lung tissue resistance, exhaled nitric oxide, linear mean intercept, immune cell counts in the bronchoalveolar lavage fluid, cytokine expression, extracellular matrix remodeling, and oxidative stress in the airways and alveolar septa were evaluated on day 28. Results showed increased respiratory parameters, inflammatory markers, and tissue remodeling in the ACO group compared to controls. Treatment with the peptides or DX attenuated or reversed these responses, with the peptides showing effectiveness in controlling hyperresponsiveness, inflammation, remodeling, and oxidative stress markers. These peptides demonstrated an efficacy comparable to that of corticosteroids in the ACO model. However, this study highlights the need for further research to assess their safety, mechanisms of action, and potential translation to clinical studies before considering these peptides for human use.

Investigating the Effects of a New Peptide, Derived from the Enterolobium contortisiliquum Proteinase Inhibitor (EcTI), on Inflammation, Remodeling, and Oxidative Stress in an Experimental Mouse Model of Asthma-Chronic Obstructive Pulmonary Disease Overlap (ACO).

The synthesized peptide derived from Enterolobium contortisiliquum (pep3-EcTI) has been associated with potent anti-inflammatory and antioxidant effects, and it may be a potential new treatment for asthma-COPD overlap-ACO). Purpose: To investigate the primary sequence effects of pep3-EcTI in an experimental ACO. BALB/c mice were divided into eight groups: SAL (saline), OVA (ovalbumin), ELA (elastase), ACO (ovalbumin + elastase), ACO-pep3-EcTI (treated with inhibitor), ACO-DX (treated with dexamethasone), ACO-DX-pep3-EcTI (treated with dexamethasone and inhibitor), and SAL-pep3-EcTI (saline group treated with inhibitor). We evaluated the hyperresponsiveness to methacholine, exhaled nitric oxide, bronchoalveolar lavage fluid (BALF), mean linear intercept (Lm), inflammatory markers, tumor necrosis factor (TNF-α), interferon (IFN)), matrix metalloproteinases (MMPs), growth factor (TGF-ß), collagen fibers, the oxidative stress marker inducible nitric oxide synthase (iNOS), transcription factors, and the signaling pathway NF-κB in the airways (AW) and alveolar septa (AS). Statistical analysis was conducted using one-way ANOVA and t-tests, significant when p < 0.05. ACO caused alterations in the airways and alveolar septa. Compared with SAL, ACO-pep3-EcTI reversed the changes in the percentage of resistance of the respiratory system (%Rrs), the elastance of the respiratory system (%Ers), tissue resistance (%Gtis), tissue elastance (%Htis), airway resistance (%Raw), Lm, exhaled nitric oxide (ENO), lymphocytes, IL-4, IL-5, IL-6, IL-10, IL-13, IL-17, TNF-α, INF-γ, MMP-12, transforming growth factor (TGF)-ß, collagen fibers, and iNOS. ACO-DX reversed the changes in %Rrs, %Ers, %Gtis, %Htis, %Raw, total cells, eosinophils, neutrophils, lymphocytes, macrophages, IL-1ß, IL-6, IL-10, IL-13, IL-17, TNF-α, INF-γ, MMP-12, TGF-ß, collagen fibers, and iNOS. ACO-DX-pep3-EcTI reversed the changes, as was also observed for the pep3-EcTI and the ACO-DX-pep3-EcTI. Significance: The pep3-EcTI was revealed to be a promising strategy for the treatment of ACO, asthma, and COPD.

Effects of a Peptide Derived from the Primary Sequence of a Kallikrein Inhibitor Isolated from Bauhinia bauhinioides (pep-BbKI) in an Asthma-COPD Overlap (ACO) Model.

(1) There are several patients with asthma-COPD overlap (ACO). A peptide derived from the primary sequence of a kallikrein inhibitor isolated from Bauhinia bauhinioides (pep-BbKI) has potent anti-inflammatory and antioxidant effects. Purpose: To investigate the effects of pep-BbKI treatment in an ACO model and compare them with those of corticosteroids. (2) BALB/c mice were divided into groups: SAL (saline), OVA (ovalbumin), ELA (elastase), ACO (ovalbumin + elastase), ACO-pep-BbKI (treated with inhibitor), ACO-DX (dexamethasone treatment), ACO-DX-pep-BbKI (both treatments), and SAL-pep-BbKI (saline group treated with inhibitor). We evaluated: hyperresponsiveness to methacholine, bronchoalveolar lavage fluid (BALF), exhaled nitric oxide (eNO), IL-1ß, IL-4, IL-5, IL-6, IL-10, IL-13, IL-17, IFN-γ, TNF-α, MMP-9, MMP-12, TGF-ß, collagen fibers, iNOS, eNO, linear mean intercept (Lm), and NF-κB in airways (AW) and alveolar septa (AS). (3) ACO-pep-BbKI reversed ACO alterations and was similar to SAL in all mechanical parameters, Lm, neutrophils, IL-5, IL-10, IL-17, IFN-γ, TNF-α, MMP-12 (AW), collagen fibers, iNOS (AW), and eNO (p > 0.05). ACO-DX reversed ACO alterations and was similar to SAL in all mechanical parameters, Lm, total cells and differentials, IL-1ß(AS), IL-5 (AS), IL-6 (AS), IL-10 (AS), IL-13 (AS), IFN-γ, MMP-12 (AS), TGF-ß (AS), collagen fibers (AW), iNOS, and eNO (p > 0.05). SAL was similar to SAL-pep-BbKI for all comparisons (p > 0.05). (4) Pep-BbKI was similar to dexamethasone in reducing the majority of alterations of this ACO model.