Inhibition of human neutrophil elastase by pentacyclic triterpenes

Sivelestat (Neutrophil Elastase Inhibitor) as an Anti-inflammatory and Anti-viral Agent: An In Silico Study

Background Sivelestat is a potent and specific neutrophil elastase inhibitor. It is clinically used in treating lung injury and respiratory distress syndrome. This engaged us to undertake the present study in which sivelestat was studied as an anti-inflammatory and anti-viral agent. Methodology The docking study of sivelestat on matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9), chikungunya virus nonstructural protein-2 (CVnsP2) protease, and influenza A (H1N9) virus neuraminidase was assessed using the Chemistry at Harvard Macromolecular Mechanics (CHARMM) Dock (CDOCK) method. Furthermore, molecular physicochemical; bioactivity; absorption, distribution, metabolism, and excretion (ADME); toxicity; and Search Tool for Interacting Chemicals (STITCH) analyses were performed by using the Molinspiration (Molinspiration Cheminformatics, Slovensky Grob, Slovak Republic), SwissADME SwissADME (Swiss Institute of Bioinformatics, Quartier Sorge - Bâtiment Amphipôle, Switzerland), pkCSM (University of Melbourne, Melbourne, Australia), and STITCH-free online tools. Results The molecular physicochemical assessment of the ligand (sivelestat) showed no (zero) violation and agreed with the thumb rule of five, otherwise known as Lipinski's rule of five. ADME prediction of the ligand (sivelestat) is shown to possess a low gastrointestinal absorption (GIA) property. Similarly, toxicity analysis of the ligand (sivelestat) is predicted to have a hepatotoxicity effect. STITCH analysis reveals that the ligand (sivelestat) has exhibited interactions with the three human proteins. Conclusions The present molecular docking studies showed that the ligand (sivelestat) has successfully docked with all four enzymes of interest. Hence, the current finding has provided a good understanding of sivelestat as an effective suppressor activity against all four enzymes: MMP-2, MMP-9, CVnsP2 protease, and influenza neuraminidase.

Plant In Vitro Culture Factories for Pentacyclic Triterpenoid Production

Pentacyclic triterpenoids are a diverse subclass of naturally occurring terpenes with various biological activities and applications. These compounds are broadly distributed in natural plant resources, but their low abundance and the slow growth cycle of plants pose challenges to their extraction and production. The biosynthesis of pentacyclic triterpenoids occurs through two main pathways, the mevalonic acid (MVA) pathway and the 2-C-methyl-D-erythritol-4-phosphate (MEP) pathway, which involve several enzymes and modifications. Plant in vitro cultures, including elicited and hairy root cultures, have emerged as an effective and sustainable system for pentacyclic triterpenoid production, circumventing the limitations associated with natural plant resources. Bioreactor systems and controlling key parameters, such as media composition, temperature, light quality, and elicitor treatments, have been optimized to enhance the production and characterization of specific pentacyclic triterpenoids. These systems offer a promising bioprocessing tool for producing pentacyclic triterpenoids characterized by a low carbon footprint and a sustainable source of these compounds for various industrial applications.

Neutrophil extracellular traps in influenza infection

Despite recent progress in developing novel therapeutic approaches and vaccines, influenza is still considered a global health threat, with about half a million mortality worldwide. This disease is caused by Influenza viruses, which are known for their rapid evolution due to different genetical mechanisms that help them develop new strains with the ability to evade therapies and immunization. Neutrophils are one of the first immune effectors that act against pathogens. They use multiple mechanisms, including phagocytosis, releasing the reactive oxygen species, degranulation, and the production of neutrophil extracellular traps. Neutrophil extracellular traps are used to ensnare pathogens; however, their dysregulation is attributed to inflammatory and infectious diseases. Here, we discuss the effects of these extracellular traps in the clinical course of influenza infection and their ability to be a potential target in treating influenza infection.

Terpenoids as Human Neutrophil Elastase (HNE) Inhibitors: A Comprehensive Review of Natural Anti-inflammatory Isoprenoids

Human neutrophil elastase (HNE) is an enzyme that plays a key role in the body's inflammatory response. It has been linked to several diseases such as chronic obstructive pulmonary disease (COPD), emphysema, and cystic fibrosis. As potential treatments for these diseases, HNE inhibitors are of great interest. Metabolites derived from plants, particularly terpenoids such as β-caryophyllene found in black pepper and other plants, and geraniol present in several essential oils, are recognized as significant sources of inhibitors for HNE. Because of their ability to inhibit HNE, terpenoids are considered promising candidates for developing novel therapies to treat inflammatory conditions such as COPD and emphysema. Furthermore, nature can serve as an excellent designer, and it may offer a safer drug candidate for inhibiting HNE production and activity in the future. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses were searched to get relevant and up-to-date literature on terpenoids as human neutrophil elastase inhibitors. This review focuses on the isolation, chemical diversity, and inhibition of human neutrophil elastase (HNE) of various terpenoids reported from natural sources up to 2022. A total of 251 compounds from various terpenoids classes have been reported. Further, it also provides a summary of HNE inhibitors and includes a thorough discussion on the structure-activity relationship.

Protective effect of soloxolone derivatives in carrageenan- and LPS-driven acute inflammation: Pharmacological profiling and their effects on key inflammation-related processes

The anti-inflammatory potential of three cyanoenone-containing triterpenoids, including soloxolone methyl (SM), soloxolone (S) and its novel derivative bearing at the C-30 amidoxime moiety (SAO), was studied in murine models of acute inflammation. It was found that the compounds effectively suppressed the development of carrageenan-induced paw edema and peritonitis as well as lipopolysaccharide (LPS)-driven acute lung injury (ALI) with therapeutic outcomes comparable with that of the reference drugs indomethacin and dexamethasone. Non-immunogenic carrageenan-stimulated inflammation was more sensitive to the transformation of C-30 of SM compared with immunogenic LPS-induced inflammation: the anti-inflammatory properties of the studied compounds against carrageenan-induced paw edema and peritonitis decreased in the order of SAO > S > > SM, whereas the efficiency of these triterpenoids against LPS-driven ALI was similar (SAO ≈ S ≈ SM). Further studies demonstrated that soloxolone derivatives significantly inhibited a range of immune-related processes, including granulocyte influx and the expression of key pro-inflammatory cytokines and chemokines in the inflamed sites as well as the functional activity of macrophages. Moreover, SM was found to prevent inflammation-associated apoptosis of A549 pneumocytes and effectively inhibited the protease activity of thrombin (IC₅₀ = 10.3 µM) tightly associated with rodent inflammatome. Taken together, our findings demonstrate that soloxolone derivatives can be considered as novel promising anti-inflammatory drug candidates with multi-targeted mechanism of action.

Anti-Inflammatory and Antioxidant Properties of β-Sitosterol in Copper Sulfate-Induced Inflammation in Zebrafish (Danio rerio)

β-Sitosterol, which is used extensively in pharmaceuticals, nutraceuticals, and cosmetics, has high nutritional value along with immunomodulatory and anti-inflammatory properties. In this study, we investigated the antioxidant and anti-inflammatory effects of β-sitosterol in zebrafish and explored the associated molecular mechanisms. In an in vivo antioxidant experiment, zebrafish (Danio rerio) larvae were treated with different concentrations of β-sitosterol and then exposed to a nonlethal concentration of CuSO₄ to induce oxidative stress. Treatment with β-sitosterol at 70 or 100 μg/mL significantly reduced CuSO₄-induced oxidative stress in the zebrafish, demonstrating the strong antioxidant activity of β-sitosterol. Treatment with β-sitosterol protected zebrafish larvae against oxidative damage from CuSO₄ by upregulating the expressions of sod and gpx4b. In a zebrafish model of inflammation, pretreatment with β-sitosterol before CuSO4 exposure inhibited neutrophil recruitment and damage to lateral line neuromasts, indicating a potent anti-inflammatory effect derived from reductions in the expressions of il-8 and myd88. The results demonstrate the antioxidative and anti-inflammatory activities of β-sitosterol and suggest that β-sitosterol may be useful for the treatment of various inflammatory diseases.

Bioactive Saponins of Primula vulgaris Huds. Promote Wound Healing through Inhibition of Collagenase and Elastase Enzymes: in Vivo, in Vitro and in Silico Evaluations

Primula vulgaris Huds. leaves and roots were used to treat skin damage and inflammation in Anatolian Folk Medicine. This study aimed to assess the ethnopharmacological use of the plant using in vivo, in vitro, and in silico test models. Linear incision and circular excision wound models were used to determine the in vivo wound-healing potential of the plant extracts and fractions. In vitro assays including hyaluronidase, collagenase, and elastase inhibitory activities were carried out for the active compounds to discover their activity pathways. Structure-based molecular modeling was performed to understand inhibitory mechanisms regarding collagenase and elastase at the molecular level. The butanol fraction of the roots of P. vulgaris showed the highest wound-healing activity. Through activity-guided fractionation and isolation techniques, primulasaponin I (1) and primulasaponin I methyl ester (2) were stated as the major active compounds. These compounds exerted their activities through the inhibition of collagenase and elastase enzymes. Primulasaponin I methyl ester isolated from butanol fraction was found to be the strongest agent, especially with the values of 29.65 % on collagenase and 38.92 % on elastase inhibitory activity assays, as well as molecular docking studies. The present study supports scientific data for the traditional use of P. vulgaris and the wound healing properties of the plant can be referred to secondary metabolites as especially saponins found in the roots.

ANTIAGE-DB: A Database and Server for the Prediction of Anti-Aging Compounds Targeting Elastase, Hyaluronidase, and Tyrosinase

Natural products bear a multivariate biochemical profile with antioxidant, anti-inflammatory, antibacterial, and antitumoral properties. Along with their natural sources, they have been widely used both as anti-aging and anti-melanogenic agents due to their effective contribution in the elimination of reactive oxygen species (ROS) caused by oxidative stress. Their anti-aging activity is mainly related to their capacity of inhibiting enzymes like Human Neutrophil Elastase (HNE), Hyaluronidase (Hyal) and Tyrosinase (Tyr). Herein, we accumulated literature information (covering the period 1965–2020) on the inhibitory activity of natural products and their natural sources towards these enzymes. To navigate this information, we developed a database and server termed ANTIAGE-DB that allows the prediction of the anti-aging potential of target compounds. The server operates in two axes. First a comparison of compounds by shape similarity can be performed against our curated database of natural products whose inhibitory potential has been established in the literature. In addition, inverse virtual screening can be performed for a chosen molecule against the three targeted enzymes. The server is open access, and a detailed report with the prediction results is emailed to the user. ANTIAGE-DB could enable researchers to explore the chemical space of natural based products, but is not limited to, as anti-aging compounds and can predict their anti-aging potential. ANTIAGE-DB is accessed online.

Sequence Preference and Scaffolding Requirement for the Inhibition of Human Neutrophil Elastase by Ecotin Peptide

Human neutrophil elastase (hNE) is an abundant serine protease that is a major constituent of lung elastolytic activity. However, when secreted in excess, if not properly attenuated by selective inhibitor proteins, it can have detrimental effects on host tissues, leading to chronic lung inflammation and non-small cell lung cancer. To improve upon the design of inhibitors against hNE for therapeutic applications, here, we report the crystal structure of hNE in complex with an ecotin-derived peptide inhibitor. We show that the peptide binds in the non-prime substrate binding site. Unexpectedly, compared with full-length ecotin, we find that our short linear peptides and circular amide-backbone-linked peptides of ecotin are incapable of efficient hNE inhibition. Our structural insights point to a preferred amino acid sequence and the potential benefit of a scaffold for optimal binding and function of the peptide inhibitor, both of which are retained in the full-length ecotin protein. These findings will aid in the development of effective peptide-based inhibitors against hNE for targeted therapy. This article is protected by copyright. All rights reserved.

Advances in Anti-inflammatory Activity, Mechanism and Therapeutic Application of Ursolic Acid

In vivo and in vitro studies reveal that Ursolic Acid (UA) is able to counteract endogenous and exogenous inflammatory stimuli and has favorable anti-inflammatory effects. The antiinflammatory mechanisms mainly include decreasing the release of histamine in mast cells, suppressing the activities of lipoxygenase, cyclooxygenase and phospholipase, and reducing the production of nitric oxide and reactive oxygen species, blocking the activation of the signal pathway, downregulating the expression of inflammatory factors, and inhibiting the activities of elastase and complement. These mechanisms can open up new avenues for the scientific community to develop or improve novel therapeutic approaches to tackle inflammatory diseases, such as arthritis, atherosclerosis, neuroinflammation, liver diseases, kidney diseases, diabetes, dermatitis, bowel diseases, cancer. The anti-inflammatory activity, the anti-inflammatory mechanism of ursolic acid and its therapeutic applications are reviewed in this paper.

Immunomodulatory properties of triterpenes

The immune system is one of the main defence mechanisms of the human body. Inadequacy of this system or immunodeficiency results in increased risk of infections and tumours, whereas over-activation of the immune system causes allergic or autoimmune disorders. A well-balanced immune system is important for protection and for alleviation of these diseases. There is a growing interest to maintain a well-balanced immune system, especially after the Covid-19 pandemic. Many biological extracts, as well as natural products, have become popular due to their wide array of immunomodulatory effects and influence on the immune system. Triterpenes, one of the secondary metabolite groups of medicinal plants, exhibit immunomodulatory properties by various mechanisms. Different triterpenes, including components of commonly consumed plants, can promote some protection and alleviation of disease symptoms linked with immune responses and thus enhance overall well-being. This review aims to highlight the efficacy of triterpenes in light of the available literature evidence regarding the immunomodulatory properties of triterpenes. We have reviewed widely investigated immunomodulatory triterpenes; oleanolic acid, glycyrrhizin, glycyrrhetinic acid, pristimerin, ursolic acid, boswellic acid, celastrol, lupeol, betulin, betulinic acid, ganoderic acid, cucumarioside, and astragalosides which have important immunoregulatory properties. In spite of many preclinical and clinical trials were conducted on triterpenes related to their immunoregulatory actions, current studies have several limitations. Therefore, especially more clinical studies with optimal design is essential.

Two triterpenoids from Rubus fraxinifolius leaves and their tyrosinase and elastase inhibitory activities

Numerous therapeutic compounds have been isolated from naturally abundant organic resources, which may offer economical and sustainable sources of compounds with safe and efficacious biological activities. In the cosmetics industry, natural compounds with anti-aging activities are eagerly sought. Thus, we prepared various extracts from Rubus fraxinifolius leaves and used enzyme inhibition assays to isolate compounds with protective effects against skin aging. Two triterpenoids were isolated from Rubus fraxinifolius Poir. leaves. The structures were characterized by spectroscopic analyses (LC-ESI-MS, 1D/2D NMR) and comparison to reported data. Compound 1 and 2 were determined as 2,3-O-ethyleneglycol, 19-hydroxyurs-12-en-23,28-dioic acid and 2,3-O-propanediol,19-hydroxyurs-12-en-28-oic acid. Methanol extract and isolates were assessed for their inhibitory effects on elastase and tyrosinase. Compounds 1 and 2 inhibited elastase with IC₅₀ 122.199 µg/mL and 98.22 µg/mL, and also inhibited tyrosinase with IC₅₀ 207.79 µg/mL and 221.51 µg/mL, respectively. The molecular docking proved that both compounds have affinities toward the enzymes.

Ursolic Acid and Related Analogues: Triterpenoids with Broad Health Benefits

Ursolic acid (UA) is a well-studied natural pentacyclic triterpenoid found in herbs, fruit and a number of traditional Chinese medicinal plants. UA has a broad range of biological activities and numerous potential health benefits. In this review, we summarize the current data on the bioavailability and pharmacokinetics of UA and review the literature on the biological activities of UA and its closest analogues in the context of inflammation, metabolic diseases, including liver and kidney diseases, obesity and diabetes, cardiovascular diseases, cancer, and neurological disorders. We end with a brief overview of UA’s main analogues with a special focus on a newly discovered naturally occurring analogue with intriguing biological properties and potential health benefits, 23-hydroxy ursolic acid.

Bioengineering of an elastase inhibitor from Caesalpinia echinata (Brazil wood) seeds

Protease inhibitors have been widely used in several therapeutic applications such as in the treatment of bleeding disorders, hypertension, cancer and pulmonary diseases. In a previous work, we demonstrated that a Kunitz-type serine protease inhibitor isolated from the seeds of Caesalpinia echinata (CeEI) exhibits pharmacological potential in lung inflammatory diseases in which neutrophil elastase plays a crucial role. However, an important challenge in the use of natural products is to ensure a commercially viable production. In this work, we report the cloning, expression and purification of two recombinant CeEI isoinhibitors with 700 base pairs encoding two proteins with 181 amino acid residues (rCeEI-4 and rCeEI-5). After the expression, each yielding 22 mg/L of active protein, both isoinhibitors presented a molecular mass of about 23.0 kDa, evaluated by SDS-PAGE. The inhibition constants for human neutrophil elastase (HNE) were 0.67 nM (rCeEI-4) and 0.57 nM (rCeEI-5), i.e., similar to the native inhibitor (1.90 nM). Furthermore, rCeEI-4 was used as a template to design smaller functional peptides flanking the inhibitor reactive site: rCeEI-36, delimited between the amino acid residues N³⁶ and S⁸⁸ containing a disulfide bond in the reactive-site loop, and rCeEI-46, delimited between S⁴⁶ and L⁷⁵ without the disulfide bond. The yields were 18 mg/L (rCeEI-36) and 12 mg/L (rCeEI-46). Both peptides inhibit HNE in the nanomolar range (K_i 0.30 ± 0.01 and 8.80 ± 0.23, respectively). Considering their size and the inhibitory efficiency, these peptides may be considered in strategies for the development of drugs targeting pulmonary disorders where elastase is involved.

Potential use of medicinal plants from Argentinean highland as agent anti-photoaging

BACKGROUND

The overexposure to sun ultraviolet (UV) radiation produce photoaging by effect of free radicals on lipid, protein, and nucleic acid or by direct activation of responsible enzymes of cleavage of extracellular matrix components (EMC).

AIMS

To develop new anti-photoaging agents, the anti-aging activity of four "jarillas" standardized extracts from Argentina (Zuccagnia punctata Cav.,Larrea divaricata Cav.,Larrea cuneifolia Cav., and Larrea nitida Cav.) were examined.

METHODS

The effect on the activity and expression of enzymes related to photoaging (collagenase, hyaluronidase, elastase, tyrosinase) and the antioxidant capacity of four "jarillas" extracts were examined.

RESULTS

The results suggest that "jarillas" extracts could protect EMC by inhibition of skin aging-related enzymes and suppression of the expression of metalloproteinases (MMP-1) in human skin fibroblasts from photoinduced damage. Modulation of MMP-1 expression induced by UV radiation in human skin cells could be associated, at least in part, with the ROS scavenging capacity of "jarilla" extracts. The extract of Z punctata was more active than Larrea species extracts in all the trials. The activity of Z punctata and Larrea extracts could be ascribed to chalcones and lignans, major constituents of "jarillas," respectively.

CONCLUSIONS

The results obtained would indicate the potential of these adapted species to live in arid zones of Argentina, exposed to high ultraviolet radiation in production of cosmetic products and justify the promotion of their sustainable use and the development of crops.

Novel Sulfonamide Analogs of Sivelestat as Potent Human Neutrophil Elastase Inhibitors

Human neutrophil elastase (HNE) is involved in a number of essential physiological processes and has been identified as a potential therapeutic target for treating acute and chronic lung injury. Nevertheless, only one drug, Sivelestat, has been approved for clinical use and just in Japan and the Republic of Korea. Thus, there is an urgent need for the development of low-molecular-weight synthetic HNE inhibitors, and we have developed a wide variety of HNE inhibitors with various chemical scaffolds. We hypothesized that substitution of the active fragment of Sivelestat into these HNE inhibitor scaffolds could modulate their inhibitory activity, potentially resulting in higher efficacy and/or improved chemical stability. Here, we report the synthesis, biological evaluation, and molecular modeling studies of novel compounds substituted with the 4-(sulfamoyl)phenyl pivalate fragment necessary for Sivelestat activity. Many of these compounds were potent HNE inhibitors with activity in the nanomolar range (IC50 = 19-30 nM for compounds 3a, 3b, 3f, 3g, and 9a), confirming that the 4-(sulfamoyl)phenyl pivalate fragment could substitute for the N-CO group at position 1 and offer a different point of attack for Ser195. Results of molecular docking of the these pivaloyl-containing compounds into the HNE binding site supported the mechanism of inhibitory activity involving a nucleophilic attack of Ser195 from the catalytic triad onto the pivaloyl carbonyl group. Furthermore, some compounds (e.g., 3a and 3f) had a relatively good stability in aqueous buffer (t1/2 > 9 h). Thus, this novel approach led to the identification of a number of potent HNE inhibitors that could be used as leads for the further development of new therapeutics.

Review on druggable targets of key age-associated properties regulated by therapeutic agents

Aging is a biological process which accounts for the deterioration of effective physiological functions. The malfunctioning of vital organ systems leads to the onset of neurodegenerative, cardiovascular, and immunomodulatory diseases in the elder population. Age-dependent mitochondrial dysfunctions trigger the production of reactive oxygen species, which serve as a major contributing factor for the onset of age-associated diseases. The increasing burden of age-related pathologies explicates the relevance of identifying novel therapeutic agents with enhanced potency and bioavailability. Key information on the biological mechanisms of significant age-related diseases aids in understanding relevant druggable targets essential for the initiation and progression of the disease. This review provides detailed insights into the druggable targets of key anti-aging properties of therapeutic agents such as anti-oxidant, immunomodulation, cardioprotection, anti-melanogenic, and anti-elastase properties. This information aids in the development of novel therapeutic agents/ supplements with enhanced efficacy.

Neutrophil elastase inhibitory effects of pentacyclic triterpenoids from Eriobotrya japonica (loquat leaves)

ETHNOPHARMACOLOGICAL RELEVANCE

Eriobotrya japonica, a traditional herbal medicine in China and Japan, has long been used to treat chronic bronchitis and coughs.

AIM OF THE STUDY

Pentacyclic triterpenoids (PTs), especially ursolic acid (UA), have been found as reversibly and competitively human neutrophil elastase (HNE) inhibitors. However, the limited solubility and poor bioavailability of PTs hinder their clinical use. Crude plant extracts may have a greater activity than isolated constituents of the equivalent dosage. In this study, an Eriobotrya japonica (loquat leaves) extract (triterpenoid composition of loquat leaves, TCLL) with enriched PTs such as UA was prepared. The study aims to compare the HNE inhibitory (HNEI) effect in vitro and the therapeutic effect on acute lung injury (ALI) in vivo between TCLL and UA.

MATERIALS AND METHODS

An HNEI activity bioassay was performed with Sivelestat sodium hydrate as a positive control. A lipopolysaccharide (LPS)-induced lung inflammatory model was established to evaluate TCLL's therapeutic effect on ALI in vivo. The absorption of UA in TCLL and in UA alone was determined using a Caco-2 cell uptake model and LC-MS.

RESULTS

The IC₅₀ values of TCLL and UA for the HNEI effect were 3.26 ± 0.56 μg/mL and 8.49 ± 0.42 μg/mL (P < 0.01), respectively. TCLL significantly improved the inflammatory cells and inflammatory cytokine production in mice compared with the LPS group (P < 0.05). Additionally, it performed better than the UA alone group (P < 0.05). Moreover, the uptake by Caco-2 cells of UA in TCLL was higher than that in UA alone (P < 0.05).

CONCLUSION

TCLL has a significant HNEI effect in vitro and a therapeutic effect on LPS-induced inflammation in a mouse model. Both the effects are more efficient than UA. Improved absorption of PTs in TCLL may be one explanation for these results.

Safety and efficacy of the human neutrophil elastase inhibitor BAY 85-8501 for the treatment of non-cystic fibrosis bronchiectasis: A randomized controlled trial

BACKGROUND

There are only limited treatment options for patients with non-cystic fibrosis bronchiectasis (non-CF BE). Human neutrophil elastase (HNE) is a mediator of tissue destruction in non-CF BE. BAY 85-8501, a selective and reversible HNE inhibitor, could represent a new treatment option for this disease.

METHODS

This was a phase 2a, randomized, placebo-controlled, double-blind, parallel-group study. The primary objective was to assess the safety and tolerability of 1 mg BAY 85-8501 once daily (OD) for 28 days compared with placebo in patients with non-CF BE. Secondary objectives were to investigate the effects of 4 weeks of treatment with BAY 85-8501 on health-related quality of life, pulmonary function, and inflammatory and tissue damage biomarkers in sputum, blood and/or urine, and to evaluate the pharmacokinetics of BAY 85-8501.

RESULTS

Overall, 94 patients (mean age, 66 years; 53% male) were randomized (n = 47 per group), and 82 completed the study (BAY 85-8501, n = 37; placebo, n = 45). Treatment-emergent adverse events (TEAEs) occurred in 31 patients (66%) taking BAY 85-8501 and in 36 patients (77%) taking placebo, and were mostly mild or moderate. The serious TEAEs (BAY 85-8501, n = 3; placebo, n = 1) were not considered to be study-drug related. There were no changes in pulmonary function parameters from baseline to end of treatment, and health-related quality of life did not improve in any group. HNE activity in blood after zymosan challenge decreased significantly with BAY 85-8501 treatment (P = 0.0250 versus placebo). There were no significant differences in other biomarkers between treatment groups, with the exception of a small increase in interleukin-8 levels in sputum in the BAY 85-8501 group. Trough plasma concentrations of BAY 85-8501 plateaued after 2 weeks.

CONCLUSIONS

1 mg BAY 85-8501 OD had a favourable safety and tolerability profile when administered for 28 days to patients with non-CF BE. Further studies with a longer treatment duration are needed to evaluate the potential clinical efficacy in this study population.

Simultaneous elastase-, hyaluronidase- and collagenase-capillary electrophoresis based assay. Application to evaluate the bioactivity of the red alga Jania rubens

There have been many efforts to search for affordable and efficient cosmetic ingredients from natural sources and to evaluate their bioactivities using eco-responsible tools. Hyaluronidase, elastase and collagenase are responsible for the degradation of the main components of the extracellular matrix, namely the hyaluronic acid, elastin and collagen, respectively. The aim of this work was to develop a single capillary electrophoresis method to monitor simultaneously the activities of these three enzymes, without reactant immobilization or radioactivity use. The developed approach was used to evaluate the bioactivity of the red alga Jania rubens after microwave- or electrochemical-assisted extraction. For this purpose, the incubation time, the reactant concentrations, the separation buffer and the detection system were carefully chosen. CE with double detection system, LIF and HRMS connected in series, was used to ensure the simultaneous analysis of the substrates and products of the three enzymatic reactions. The optimized enzymatic conditions allowed the use of the same protocol to assess the 3 enzyme activities. These conditions consisted of 10 min pre-incubation of the enzyme (with alga extract) at 37 °C; 10 min incubation with the substrate at 37 °C and 10 min stop-time at 90 °C. 1.4 nL of each reaction mixture were co-injected into a 85 cm total length capillary using short-end injection. Ammonium acetate (50 mM, pH 9.0) was used for electrophoretic separation. All substrates and products were simultaneously detected in less than 10 min with good peak symmetry and efficiency, sufficient intra-day and inter-day repeatabilities (RSD < 4.5%; n = 3) and excellent LOQ (<5 nM). The results obtained using this multiple CE-based enzymatic assay showed the significant effect of Jania rubens ethanolic extracts on elastase, hyaluronidase and the metalloproteinase MMP-1.

Inhibition of Human Kallikrein 5 Protease by Triterpenoids from Natural Sources

Stratum corneum tryptic enzyme kallikrein 5 (KLK5) is a serine protease that is involved in the cell renewal and maintenance of the skin barrier function. The excessive activation of KLK5 causes an exacerbation of dermatoses, such as rosacea and atopic dermatitis. Some triterpenoids are reported to suppress the serine proteases. We aimed to investigate whether bioactive triterpenoids modulate the KLK5 protease. Nineteen triterpenoids occurring in medicinal crude drugs were evaluated using an enzymatic assay to measure the anti-KLK5 activity. The KLK5-dependent cathelicidin peptide LL-37 production in human keratinocytes was examined using immunoprecipitation and Western blotting. Screening assays for evaluating the anti-KLK5 activity revealed that ursolic acid, oleanolic acid, saikosaponin b₁, tumulosic acid and pachymic acid suppressed the KLK5 protease activity, although critical molecular moieties contributing to anti-KLK5 activity were unclarified. Ursolic acid and tumulosic acid suppressed the proteolytic processing of LL-37 in keratinocytes at ≤10 μM; no cytotoxicity was observed. Both triterpenoids were detected in the plasma of rats administered orally with triterpenoid-rich crude drug Jumihaidokuto. Our study reveals that triterpenoids, such as ursolic acid and tumulosic acid, modulate the KLK5 protease activity and cathelicidin peptide production. Triterpenoids may affect the skin barrier function via the regulation of proteases.

Human neutrophil elastase inhibition studied by capillary electrophoresis with laser induced fluorescence detection and microscale thermophoresis

Capillary electrophoresis-laser induced fluorescence (CZE-LIF) and microscale thermophoresis (MST) were used for the first time to study the inhibition of human neutrophil elastase (HNE). We recently studied HNE kinetics (Km and Vmax) by developing an in-capillary CZE-LIF assay based on transverse diffusion of laminar flow profiles (TDLFP) for reactant mixing. In this work, the former assay was adapted to monitor HNE inhibition. Two natural well known HNE inhibitors from the triterpene family, ursolic acid and oleanolic acid, were tested to validate the developed assay. Since the solubility of pentacyclic triterpenes in aqueous media where the enzymatic reaction will take place is limited, the effect of DMSO and ethanol on HNE was studied using microscale thermophoresis (MST). An agglomeration of the enzyme was revealed when preparing the inhibitor in 5% (v/v) DMSO. This phenomenon did not occur in the presence of ethanol. Therefore, ethanol was used as inhibitor solvent, at a limited percentage of 20% (v/v). In these conditions and after optimization of the TDLFP approach, the repeatability (RSD on migration times and peak-areas inferior to 2.2%) of the CZE-LIF assay and the sensitivity (LOQ of few nM) were found to be satisfactory for conducting inhibition assays. IC50 values for ursolic and oleanolic acid were successfully determined. They were respectively equal to 5.62±0.10μM (r(2)=0.9807; n=3) and to 8.21±0.23μM (r(2)=0.9887; n=3). Excellent agreement was found between the results obtained by CE and those reported in literature which validates the developed method. Particularly, the CE-based assay is able to rank HNE inhibitors relative to each other. Furthermore, MST technique was used for evaluating HNE interaction with the ursolic acid. Up to 16 capillaries were automatically processed to obtain in one titration experiment the dissociation constant for the HNE-ursolic acid complex. Ki was found to be 2.72±0.66μM (n=3) which is in excellent agreement with the value determined by CE enzyme inhibition studies (Ki=2.81μM) confirming the reliability of the developed CE assay and the competitive inhibition mode of ursolic acid.

Pulmonary Complications of Azanucleoside Therapy in Patients with Myelodysplastic Syndrome and Acute Myelogenous Leukemia

Our primary aim was to identify potential risk factors and clinical outcome of azanucleoside induced pulmonary complications in patients with myelodysplastic syndrome (MDS) and Acute Myelogenous Leukemia (AML). We present an 89-year-old female with MDS derived AML who developed fatigability, hypoxemia, and bilateral lung infiltrates indicating interstitial lung disease after 11 cycles of azanucleoside. In addition, we describe a cohort of six MDS patients with fever, cough, dyspnea, and pulmonary infiltrates at early time point during azanucleoside treatment. Early and late onset of pulmonary manifestations suggest different pathogenic mechanisms. Brief azanucleoside discontinuation and steroids led to rapid improvement in symptoms.

Proteinases and plaque rupture: unblocking the road to translation

PURPOSE OF REVIEW

To review progress over the past 5 years in relating extracellular proteinases to plaque rupture, the cause of most myocardial infarctions, and consider the most promising prospects for developing related treatments.

RECENT FINDINGS

Cysteinyl cathepsins have been implicated in multiple macrophage functions that could promote plaque rupture. Cathepsin K is an attractive target because it is a collagenase and selective inhibitors are already being used in phase III clinical trials. Several serine proteinases clearly influence vascular remodelling and atherogenesis but important, unrelated actions limit their value as therapeutic targets. Among the metalloproteinases, new evidence supports roles for A Disintigrin and Metalloproteinases (ADAMs), including ADAM-10, ADAM-17 and ADAM-33, which suggest that selective inhibitors might be effective treatments. For ADAMs with ThromboSpondin domains (ADAMTSs), there are biological and genome-wide association data linking ADAMTS-7 to incidence of coronary heart disease but not increased risk of myocardial infarctions. In the case of matrix metalloproteinases (MMPs), selective inhibitors of MMP-12 and MMP-13 are available and may be appropriate for development as therapies. Novel targets, including MMP-8, MMP-10, MMP-14, MMP-19, MMP-25 and MMP-28, are also being considered.

SUMMARY

New opportunities exist to exploit proteinases as therapeutic targets in plaque rupture.