Natural Products for the Management of Asthma and COPD.

Chronic airway inflammatory diseases like asthma, chronic obstructive pulmonary disease (COPD), and their associated exacerbations cause significant socioeconomic burden. There are still major obstacles to effective therapy for controlling severe asthma and COPD progression. Advances in understanding the pathogenesis of the two diseases at the cellular and molecular levels are essential for the development of novel therapies. In recent years, significant efforts have been made to identify natural products as potential drug leads for treatment of human diseases and to investigate their efficacy, safety, and underlying mechanisms of action. Many major active components from various natural products have been extracted, isolated, and evaluated for their pharmacological efficacy and safety. For the treatment of asthma and COPD, many promising natural products have been discovered and extensively investigated. In this chapter, we will review a range of natural compounds from different chemical classes, including terpenes, polyphenols, alkaloids, fatty acids, polyketides, and vitamin E, that have been demonstrated effective against asthma and/or COPD and their exacerbations in preclinical models and clinical trials. We will also elaborate in detail their underlying mechanisms of action unraveled by these studies and discuss new opportunities and potential challenges for these natural products in managing asthma and COPD.

Erratum: Closing the gap for cervical cancer research in Vietnam: current perspectives and future opportunities: a report from the 5th Gynecologic Cancer InterGroup (GCIG) Cervical Cancer Research Network (CCRN) Education Symposium.

This corrects the article on p. e88 in vol. 34, PMID: 37668081.

Degradation of MK2 with natural compound andrographolide: A new modality for anti-inflammatory therapy.

The p38MAPK-MK2 signaling axis functions as an initiator of inflammation. Targeting the p38MAPK-MK2 signaling axis represents a direct therapeutic intervention of inflammatory diseases. We described here a novel role of andrographolide (AG), a small-molecule ent-labdane natural compound, as an inhibitor of p38MAPK-MK2 axis via MK2 degradation. AG was found to bind to the activation loop of MK2, located at the interface of the p38MAPK-MK2 biomolecular complex. This interaction disrupted the complex formation and predisposed MK2 to proteasome-mediated degradation. We showed that AG induced MK2 degradation in a concentration- and time-dependent manner and exerted its anti-inflammatory effects by enhancing the mRNA-destabilizing activity of tristetraprolin, thereby inhibiting pro-inflammatory mediator production (e.g., TNF-α, MCP-1). Administration of AG via intratracheal (i.t.) route to mice induced MK2 downregulation in lung alveolar macrophages, but not lung tissues, and prevented macrophage activation. Our study also demonstrated that the anti-inflammatory effects achieved by AG via MK2 degradation were more durable and sustained than that achieved by the conventional MK2 kinase inhibitors (e.g., PF-3644022). Taken together, our findings illustrated a novel mode of action of AG by modulating the p38MAPK-MK2 signaling axis and would pave the way for the development of a novel class of anti-inflammatory agents targeting MK2 for degradation by harnessing the privileged scaffold of AG.

Angiotensin II type-2 receptor activation in alveolar macrophages mediates protection against cigarette smoke-induced chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death globally. Cumulative evidence has implicated renin-angiotensin system (RAS) in the pathogenesis of COPD. Alveolar macrophages (AMs) are the first line immune defense in the respiratory system and play a critical role in the lung homeostasis. This study aimed to investigate the role of AMs in contributing to the protective effects of angiotensin II type-2 receptor (AT2R) activation in cigarette smoke (CS)-induced COPD. The AM polarization, phagocytosis and metabolism, and the underlying biochemical mechanisms of compound 21 (C21), a selective and potent non-peptide small molecule AT2R agonist, were evaluated in a two-week CS-induced COPD mouse model. C21 restored AM phagocytosis ability, reversing CS-induced AM phagocytosis impairment. CS exposure polarized AMs towards M1 phenotype, whereas, C21 skewed the CS-exposed AMs towards M2 phenotype. C21 reprogrammed CS-exposed AM metabolism from a high glycolysis-driven process to support inflammation energy demand to a high mitochondrial respiration process to limit inflammation. Besides, C21 upregulated AT2R and Mas receptor levels in CS-exposed AMs, favoring the anti-inflammatory Ang II/AT2R axis and Ang 1-7/Mas axis in the RAS. C21 restored the normal levels of sirtuin 1 (SIRT1) and MAPK phosphatase 1 (MKP1) in CS-exposed AMs, leading to the reduction of phospho-p38, phospho-ERK and p65 subunit of NF-κB levels in CS-exposed AMs. We report here for the first time that AT2R agonist C21 acts by boosting the protective functions of AMs against CS-induced COPD, and our results support the development of AT2R agonist for the treatment of COPD.

Polypharmacology of andrographolide: beyond one molecule one target.

Covering: 1951 to 2020Andrographolide is one of the most widely studied plant secondary metabolites, known to display diverse pharmacological actions. Current literature has documented a sizeable list of pharmacological targets for andrographolide, suggesting its multi-targeting nature. Many of these targets are central to the pathophysiology of highly prevalent diseases such as cardiovascular diseases, neurodegenerative disorders, autoimmunity, and even cancer. Despite its well-documented therapeutic efficacy in various disease models, for years, the discrepancies between in vivo bioavailability and bioactivity of andrographolide and the debate surrounding its multi-targeting properties (polypharmacology or promiscuity?) have hindered the development of this versatile molecule into a potential therapeutic agent. Is andrographolide a valuable lead for therapeutic development or a potential invalid metabolic panacea (IMP)? This perspective article aims to discuss this by considering various contributing factors to the polypharmacology of andrographolide.

From irreversible to reversible covalent inhibitors: Harnessing the andrographolide scaffold for anti-inflammatory action.

Covalent drugs with prolonged actions often show superior potency, yet integrated strategies for optimizing their structural and electronic features are lacking. Herein, we present our effort directed towards understanding the contribution of chemical reactivity to biological potency to rationally design new covalent inhibitors based on the ent-ladane andrographolide scaffold for anti-inflammatory action. Specifically, a series of andrographolide derivatives comprising various Michael acceptors was developed and their thiol reactivity was assayed under various chemical and biological conditions. The cell-based SAR studies permitted the assessment of the inhibitor efficacy in more complex systems, which were often limited in traditional covalent drug development using isolated proteins or peptides. Our in vitro study identified enone 17 as the most promising candidate which demonstrated potent anti-inflammatory activity and superior safety profiles as compared to the lead compound andrographolide. Its reversibility following a Michael addition reaction with biological thiols resulted in more predictable pharmacological responses. In addition, 17 exhibited good in vivo efficacy at doses as low as 0.3 mg/kg when tested in LPS-induced acute lung injury model. Given a good balance of chemical reactivity and biological potency, enone 17 potentially offers a new therapeutic option based on natural product chemistry for the management of inflammatory conditions.

Male Partner Linkage to Clinic-Based Services for Sexually Transmitted Infections and Human Immunodeficiency Virus Services Following Couple Home-Based Education and Testing.

BACKGROUND: Home-based human immunodeficiency virus (HIV) testing and education has increased HIV test uptake and access to health services among men. We studied how a home-based antenatal intervention influenced male partner utilization of clinic-based HIV and sexually transmitted infection (STI) services, linkage to HIV care and medical circumcision. METHODS: We conducted a secondary analysis within a randomized controlled trial of pregnant women attending antenatal care in Kenya. Women and their male partners received either a home-based couple intervention or an invitation letter for clinic-based couple HIV testing. The home-based intervention included education on STI symptoms, STI and HIV treatment and male circumcision for HIV prevention. Male self-reported outcomes were compared using relative risks at 6 months postpartum. RESULTS: Among 525 women, we reached 487 (93%) of their male partners; 247 men in the intervention arm and 240 men in the control arm. Men who received the intervention were more likely to report an STI consultation (n = 47 vs. 16; relative risk, 1.59; 95% confidence interval, 1.33-1.89). Among 23 men with newly diagnosed HIV, linkage to HIV care was reported by 4 of 15 in the intervention (3 men had missing linkage data) and 3 of 5 men in the control arms (relative risk, 0.66; 95% confidence interval, 0.34-1.29). Although the intervention identified 3 times more men with new HIV infection, the study lacked power to find significant differences in linkage to HIV care. Few eligible men sought medical circumcision (4 of 72 intervention and 2 of 88 control). CONCLUSIONS: Home-based couple education and testing increased STI consultations among male partners of pregnant women, but appeared insufficient to overcome the barriers involved in linkage to HIV care and medical circumcision.

The identification of naturally occurring labdane diterpenoid calcaratarin D as a potential anti-inflammatory agent.

In this study we report, for the first time, the synthesis of the natural product calcaratarin D via a stereo- and regio-selective aldol condensation with (S)-ß-hydroxy-γ-butyrolactone as key steps. A concise synthetic route (under 10 steps) to a series of structurally related normal-labdane diterpenes was also developed and their anti-inflammatory activities were evaluated in an in vitro model of inflammation. The structure-activity relationships (SARs) pertaining to the labdane scaffold were elucidated and results suggest that an α-alkylidene-ß-hydroxy-γ-butyrolactone system is necessary for potent activity in the labdanes. Our studies identified the natural product calcaratarin D (1) as a promising anti-inflammatory agent, which effectively modulates the production of pro-inflammatory mediators (e.g., TNF-α, IL-6, NO) at both transcriptional and translational levels. These inhibitory effects are likely to occur via the suppression of nuclear factor kappa B (NF-κB) activation by reducing the p65 nuclear translocation but not its phosphorylation or protein expression. Calcaratarin D exhibited significantly greater inhibition of NF-κB activation than andrographolide, a well-known NF-κB inhibitor from the labdane family, suggesting that a normal-configuration labdane ring or the absence of hydroxyl groups at C-3 and C-19 positions is favorable for potent NF-κB inhibition. We further investigated the effects of calcaratarin D on the upstream signalling pathways and found that the compound selectively suppressed the LPS-induced activation of PI3K/Akt pathway without affecting much of the MAPK (i.e., ERK, JNK, and p38) activation. These findings demonstrate that calcaratarin D exerts its anti-inflammatory effects via a selective Akt-NF-κB-mediated mechanism and potentially offers a new therapeutic strategy for the management of inflammatory diseases.

Labdane diterpenoids as potential anti-inflammatory agents.

The search for new anti-inflammatory agents is challenging due to the complexity of the inflammatory process and its role in host defense. Over the past few decades, a significant body of evidence has emerged, supporting the prominent role of labdane diterpenoids in therapeutic interventions of various inflammatory diseases. The anti-inflammatory activity of labdane diterpenoids has been attributed mainly to the inhibition of nuclear factor-κB (NF-κB) activity, the modulation of arachidonic acid (AA) metabolism and the reduction of nitric oxide (NO) production. This article provides extensive coverage of naturally occurring labdane diterpenes, discovered between 1981 and 2016, which have been verified as NF-κB, NO, or AA modulators. Herein, we also discuss the role of Michael acceptor, a common structural feature present in most of the active labdane diterpenes, and its association with NF-κB signaling inhibition. In the cases where a sufficient amount of data exists, structure-activity relationship (SAR) studies and clinical studies performed on the anti-inflammatory labdane diterpenoids are also discussed.

Tuberculosis Treatment Outcomes Among HIV/TB-Coinfected Children in the International Epidemiology Databases to Evaluate AIDS (IeDEA) Network.

INTRODUCTION: Management of tuberculosis (TB) is challenging in HIV/TB-coinfected children. The World Health Organization recommends nucleic acid amplification tests for TB diagnosis, a 4-drug regimen including ethambutol during intensive phase (IP) of treatment, and initiation of antiretroviral therapy (ART) within 8 weeks of TB diagnosis. We investigated TB treatment outcomes by diagnostic modality, IP regimen, and ART status. METHODS: We conducted a retrospective cohort study among HIV/TB-coinfected children enrolled at the International Epidemiology Databases to Evaluate AIDS treatment sites from 2012 to 2014. We modeled TB outcome using multivariable logistic regression including diagnostic modality, IP regimen, and ART status. RESULTS: Among the 386 HIV-infected children diagnosed with TB, 20% had microbiologic confirmation of TB, and 20% had unfavorable TB outcomes. During IP, 78% were treated with a 4-drug regimen. Thirty-one percent were receiving ART at the time of TB diagnosis, and 32% were started on ART within 8 weeks of TB diagnosis. Incidence of ART initiation within 8 weeks of TB diagnosis was higher for those with favorable TB outcomes (64%) compared with those with unfavorable outcomes (40%) (P = 0.04). Neither diagnostic modality (odds ratio 1.77; 95% confidence interval: 0.86 to 3.65) nor IP regimen (odds ratio 0.88; 95% confidence interval: 0.43 to 1.80) was associated with TB outcome. DISCUSSION: In this multinational study of HIV/TB-coinfected children, many were not managed as per World Health Organization guidelines. Children with favorable TB outcomes initiated ART sooner than children with unfavorable outcomes. These findings highlight the importance of early ART for children with HIV/TB coinfection, and reinforce the need for implementation research to improve pediatric TB management.

Can We Accurately Time the Administration of Antenatal Corticosteroids for Preterm Labor?

Background. Accurate timing of antenatal corticosteroids (ACS) has resulted in improved neonatal outcomes. Objectives. Our primary objective was to determine predictors for optimal timing of ACS in women presenting with spontaneous preterm labor. Study Design. A retrospective cohort study of women receiving ACS for spontaneous preterm birth was conducted. Women were included if they presented with preterm labor or preterm premature rupture of membranes. Accurate timing of ACS was defined as administration within 7 days of delivery. Maternal demographic and obstetrics characteristics were compared between the groups receiving ACS ≤7 days and >7 days from delivery. Statistical analyses were performed using parametric and nonparametric tests. P < 0.05 was considered significant. Results. The study included 215 subjects. Median latency from ACS administration to delivery was 6 days (IQR 32). Accurate timing of ACS occurred in 113 (53%) women and was associated with rupture of membranes (OR 13.8, 95% CI 5.9-32.6), cervical change (OR 7.1, 95% CI 3.0-17.1), and cervical dilation ≥ 2 cm (OR 3.9, 95% CI 1.5-10.3). Conclusions. Rupture of membranes, cervical change, and cervical dilation ≥ 2 cm were strong predictors of optimal timing. 53% of women with preterm labor received ACS optimally.

A Potent Anti-influenza Compound Blocks Fusion through Stabilization of the Prefusion Conformation of the Hemagglutinin Protein.

An ultrahigh-throughput screen was performed to identify novel small molecule inhibitors of influenza virus replication. The screen employed a recombinant influenza A/WSN/33 virus expressing Renilla luciferase and yielded a hit rate of 0.5%, of which the vast majority showed little cytotoxicity at the inhibitory concentration. One of the top hits from this screen, designated S20, inhibits HA-mediated membrane fusion. S20 shows potent antiviral activity (IC50 = 80 nM) and low toxicity (CC50 = 40 µM), yielding a selectivity index of 500 and functionality against all of the group 1 influenza A viruses tested in this study, including the pandemic H1N1 and avian H5N1 viruses. Mechanism of action studies proved a direct S20-HA interaction and showed that S20 inhibits fusion by stabilizing the prefusion conformation of HA. In silico docking studies were performed, and the predicted binding site in HA2 corresponds with the area where resistance mutations occurred and correlates with the known role of this region in fusion. This high-throughput screen has yielded many promising new lead compounds, including S20, which will potentially shed light on the molecular mechanisms of viral infection and serve as research tools or be developed for clinical use as antivirals.

Diffuse decapping enzyme DCP2 accumulates in DCP1 foci under heat stress in Arabidopsis thaliana.

The decapping enzymes DCP1 and DCP2 are components of a decapping complex that degrades mRNAs. DCP2 is the catalytic core and DCP1 is an auxiliary subunit. It has been assumed that DCP1 and DCP2 are consistently co-localized in cytoplasmic RNA granules called processing bodies (P-bodies). However, it has not been confirmed whether DCP1 and DCP2 co-localize in Arabidopsis thaliana. In this study, we generated DCP1-green fluorescent protein (GFP) and DCP2-GFP transgenic plants that complemented dcp1 and dcp2 mutants, respectively, to see whether localization of DCP2 is identical to that of DCP1. DCP2 was present throughout the cytoplasm, whereas DCP1 formed P-body-like foci. Use of DCP1-GFP/DCP2-red fluorescent protein (RFP) or DCP1-RFP/DCP2-GFP plants showed that heat treatment induced DCP2 assembly into DCP1 foci. In contrast, cold treatment did not induce DCP2 assembly, while the number of DCP1 foci increased. These changes in DCP1 and DCP2 localization during heat and cold treatments occurred without changes in DCP1 and DCP2 protein abundance. Our results show that DCP1 and DCP2 respond differently to environmental changes, indicating that P-bodies have diverse DCP1 and DCP2 proportions depending on environmental conditions. The localization changes of DCP1 and DCP2 may explain how specific mRNAs are degraded during changes in environmental conditions.

Positive regulation of TRAF6-dependent innate immune responses by protein phosphatase PP1-γ.

Innate immune sensors such as Toll-like receptors (TLRs) differentially utilize adaptor proteins and additional molecular mediators to ensure robust and precise immune responses to pathogen challenge. Through a gain-of-function genetic screen, we identified the gamma catalytic subunit of protein phosphatase 1 (PP1-γ) as a positive regulator of MyD88-dependent proinflammatory innate immune activation. PP1-γ physically interacts with the E3 ubiquitin ligase TRAF6, and enhances the activity of TRAF6 towards itself and substrates such as IKKγ, whereas enzymatically inactive PP1-γ represses these events. Importantly, these activities were found to be critical for cellular innate responses to pathogen challenge and microbial clearance in both mouse macrophages and human monocyte lines. These data indicate that PP1-γ phosphatase activity regulates overall TRAF6 E3 ubiquitin ligase function and promotes NF-κB-mediated innate signaling responses.

Cofactors required for TLR7- and TLR9-dependent innate immune responses.

Pathogens commonly utilize endocytic pathways to gain cellular access. The endosomal pattern recognition receptors TLR7 and TLR9 detect pathogen-encoded nucleic acids to initiate MyD88-dependent proinflammatory responses to microbial infection. Using genome-wide RNAi screening and integrative systems-based analysis, we identify 190 cofactors required for TLR7- and TLR9-directed signaling responses. A set of cofactors were crossprofiled for their activities downstream of several immunoreceptors and then functionally mapped based on the known architecture of NF-κB signaling pathways. Protein complexes and pathways involved in ubiquitin-protein ligase activities, sphingolipid metabolism, chromatin modifications, and ancient stress responses were found to modulate innate recognition of endosomal nucleic acids. Additionally, hepatocyte growth factor-regulated tyrosine kinase substrate (HRS) was characterized as necessary for ubiquitin-dependent TLR9 targeting to the endolysosome. Proteins and pathways identified here should prove useful in delineating strategies to manipulate innate responses for treatment of autoimmune disorders and microbial infection.

Thirty year monitoring of PCBs, organochlorine pesticides and tetrabromodiphenylether in eel from The Netherlands.

Because of their excellent properties as a biomonitor, yellow eels (Anguilla anguilla) have been used for time-trend monitoring of polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and tetrabrominated diphenylether (tetra-BDE). The program has now lasted for thirty years and has delivered valuable information on trends and spatial differences of these compounds in the delta of the rivers Rhine and Meuse and other Dutch canals, rivers and lakes. Specific local PCB, HCH and dieldrin contaminations were identified. Temporal trends show a slow decrease of PCB concentrations since 1977. Eels from the rivers Rhine and Meuse still exceed present European maximum residue limits for dioxin-like PCBs. Apart from some exceptions, OCP and tetra-BDE concentrations have also decreased, and more than those of PCBs. Fat contents of eel have decreased from an average of 21 to ca. 13%. This decrease in fat contents, coincides with the strong reduction of the European eel stock.

[Mechanisms and causes of death in 143 Vietnamese HIV-infected patients hospitalized for tuberculosis]. / Evolutions fatales chez les patients vietnamiens co-infectés par le virus VIH et la tuberculose BAAR (+) au cours ou au décours immédiat de leur hospitalisation.

OBJECTIVE OF THE STUDY: To know the mechanisms and causes of death in Vietnamese VIH-infected patients hospitalized for tuberculosis. METHODS: Retrospective analysis of a monocentric cohort of 143 consecutive co infected patients admitted to Pham Ngoc Thach Hospital, in Ho Chi Minh City, between January 2004 and November 2004. MAIN RESULTS: All the patients were HIV-infected and AFB smear positive. The CD4 T lymphocyte count was 55/mm3 and the body mass index was 15.8 +/- 2 kg/m2. During the first three months after hospital admission and tuberculosis diagnosis, the percentage of deaths was 28.7% (41/143). The mechanisms of deaths were: progressive cachexia, acute respiratory failure, cardiogenic or bacteremic shock, coma and unexpected cardio respiratory arrest. The causes of death were tuberculosis (particularly mechanical complications such as compressive pneumothorax, pericarditis or pleuritis), metabolic disorders (mainly hyponatrémie and dyskaliema) and associated infection. In multivariate analysis, two parameters (available at admission) were predictive of short-term death: anemia (p=0.024) and hyponatrémie (p=0.026). CONCLUSION: The short term mortality of co infected patients with AIDS and tuberculosis remains high in developing countries. However, some causes of death such as compressive pneumothorax-pleuritis-pericarditis, metabolic disorder or even associated opportunistic infection i. e. pneumocystosis may be prevented or cured. Consequently, such patients must be carefully monitored and more particularly those with severe anemia and/or hyponatrémie at admission. Similarly appropriate diagnostic algorithms must be used in case of unfavorable evolution particularly to diagnose curable complication.