Effect of pollution on allergy/immunology

Biological Activities, Pharmacokinetics and Toxicity of Nootkatone: A Review

Abstract:

Plant-based drugs have a significant impact on modern therapeutics due to their vast array of pharmacological activities. The integration of herbal plants in the current healthcare system has emerged as a new field of research. It can be used for the identification of novel lead compound candidates for future drug development. Nootkatone is a sesquiterpene derivative and an isolate of grapefruit. Shreds of evidence illustrate that nootkatone targets few molecular mechanisms to exhibit its pharmacological activity and yet needs more exploration to be established. The current review is related to nootkatone, drafted through a literature search using research articles and books from different sources, including Science Direct, Google Scholar, Elsevier, PubMed, and Scopus. It has been reported to possess a wide range of pharmacological activities such as anti-inflammatory, anticancer, antibacterial, hepatoprotective, neuroprotective, and cardioprotective. Although preclinical studies in experimental animal models suggest that nootkatone has therapeutic potential, it is further warranted to evaluate its toxicity and pharmacokinetic parameters before being applied to humans. Hence in the present review, we have summarized the scientific knowledge on nootkatone with a particular emphasis on its pharmacological properties to encourage researchers for further exploration in preclinical and clinical settings.

Alpha-linolenic acid inhibits IgE-mediated anaphylaxis by inhibiting Lyn kinase and suppressing mast cell activation

Excessive reactions to allergens can induce systemic, life-threatening physiological dysfunction (anaphylaxis) in humans. The surface of mast cells expresses high-affinity IgE receptors that play a vital role during anaphylaxis. Alpha-linolenic acid (ALA) is an essential non-toxic fatty acid in humans. Since it has been reported having potential to regulate pro-inflammatory reactions, we postulated that ALA could inhibit anaphylaxis by down-regulating Lyn kinase phosphorylation. We found that local and systematic inflammation induced by albumin from chicken egg white (OVA) were attenuated by ALA in vivo. Furthermore, ALA inhibited IgE-mediated Ca²⁺ mobilization, degranulation, and cytokine release in Laboratory of Allergic Disease 2 (LAD2) cells. The western blot results showed that ALA down-regulate the FcεRI/Lyn/Syk signaling pathway by suppressing Lyn kinase activity. Therefore, ALA could serve as a therapeutic drug candidate for preventing IgE-mediated anaphylaxis.

RNA viruses in the house dust mite Dermatophagoides pteronyssinus, detection in environmental samples and in commercial allergen extracts used for in vivo diagnosis

BACKGROUND

Allergy to house dust mites (HDM), the most important source of indoor allergens worldwide, is diagnosed and treated using natural extracts from cultures that can contain immunoactive components from the HDM microbiome, including mite-infecting viruses. This study aimed to contribute to the discovery and characterization of RNA viruses from Dermatophagoides pteronyssinus, followed by their detection in different mite-derived sources.

METHODS

Viruses were assembled after in silico metatranscriptomic analysis of D. pteronyssinus RNA samples, visualized by electron microscopy, and RNA detected by direct RT-PCR or data mining. Mite culture performance was evaluated in vivo.

RESULTS

Seven RNA viruses were identified in our laboratory stock colony. Picornavirus-like viral particles were detected in epithelial cells of the digestive system and in fecal pellets. Most of these viruses could be persistently transmitted to an inbred virus-free colony by inoculating fecal material from the stock colony. Upon viral infection, no significant effect could be seen on mite population growth. Transcriptomic screening confirmed the presence of homolog sequences to these viruses in independent laboratory stocks of D. pteronyssinus and in other Astigmata mites. Noteworthy, RNA from most of the viruses could be detected by RT-PCR on house dust samples, reference standards, and/or commercial diagnostic D. pteronyssinus extracts.

CONCLUSIONS

Our results show that viral infections are common and widespread in D. pteronyssinus, both in natural and culture-based growth conditions. Potential effects on the mites themselves and consequences toward allergenicity in humans whether exposed naturally or after immunotherapy are discussed.

Glutathione S-transferases and their implications in the lung diseases asthma and chronic obstructive pulmonary disease: Early life susceptibility?

Our lungs are exposed daily to airborne pollutants, particulate matter, pathogens as well as lung allergens and irritants. Exposure to these substances can lead to inflammatory responses and may induce endogenous oxidant production, which can cause chronic inflammation, tissue damage and remodeling. Notably, the development of asthma and Chronic Obstructive Pulmonary Disease (COPD) is linked to the aforementioned irritants. Some inhaled foreign chemical compounds are rapidly absorbed and processed by phase I and II enzyme systems critical in the detoxification of xenobiotics including the glutathione-conjugating enzymes Glutathione S-transferases (GSTs). GSTs, and in particular genetic variants of GSTs that alter their activities, have been found to be implicated in the susceptibility to and progression of these lung diseases. Beyond their roles in phase II metabolism, evidence suggests that GSTs are also important mediators of normal lung growth. Therefore, the contribution of GSTs to the development of lung diseases in adults may already start in utero, and continues through infancy, childhood, and adult life. GSTs are also known to scavenge oxidants and affect signaling pathways by protein-protein interaction. Moreover, GSTs regulate reversible oxidative post-translational modifications of proteins, known as protein S-glutathionylation. Therefore, GSTs display an array of functions that impact the pathogenesis of asthma and COPD.

In this review we will provide an overview of the specific functions of each class of mammalian cytosolic GSTs. This is followed by a comprehensive analysis of their expression profiles in the lung in healthy subjects, as well as alterations that have been described in (epithelial cells of) asthmatics and COPD patients. Particular emphasis is placed on the emerging evidence of the regulatory properties of GSTs beyond detoxification and their contribution to (un)healthy lungs throughout life. By providing a more thorough understanding, tailored therapeutic strategies can be designed to affect specific functions of particular GSTs.

Tick Salivary Compounds for Targeted Immunomodulatory Therapy

Immunodeficiency disorders and autoimmune diseases are common, but a lack of effective targeted drugs and the side-effects of existing drugs have stimulated interest in finding therapeutic alternatives. Naturally derived substances are a recognized source of novel drugs, and tick saliva is increasingly recognized as a rich source of bioactive molecules with specific functions. Ticks use their saliva to overcome the innate and adaptive host immune systems. Their saliva is a rich cocktail of molecules including proteins, peptides, lipid derivatives, and recently discovered non-coding RNAs that inhibit or modulate vertebrate immune reactions. A number of tick saliva and/or salivary gland molecules have been characterized and shown to be promising candidates for drug development for vertebrate immune diseases. However, further validation of these molecules at the molecular, cellular, and organism levels is now required to progress lead candidates to clinical testing. In this paper, we review the data on the immuno-pharmacological aspects of tick salivary compounds characterized in vitro and/or in vivo and present recent findings on non-coding RNAs that might be exploitable as immunomodulatory therapies.

Paeoniflorin inhibits IgE-mediated allergic reactions by suppressing the degranulation of mast cells though binding with FcϵRI alpha subunits

Paeoniflorin (PF), a monoterpene glycoside isolated from the aqueous extract of the Chinese herb Radix Paeoniae Alba, has been used for treating various inflammatory diseases. In this study, we aimed to investigate the anti-allergic activities of PF. The anti-anaphylactic activity of PF was investigated using mast cell (MC) degranulation assay as well as Ca²⁺ influx in vitro and skin swelling and extravasation assays in vivo. The results showed that PF inhibited MC degranulation (histamine release from 74.5 ± 4.95 ng/ml to 58.7 ± 6.06 ng/ml) and Ca²⁺ influx challenged by DNP-BSA in vitro. In addition, PF reduced the degree of swelling and Evans blue exudation in mice paws. Furthermore, PF dose-dependently reduced serum inflammatory mediator release in mice sensitized with ovalbumin for 48 h by inhibiting MC degranulation. Molecular docking study revealed that PF bound better with the α subunit of FcϵRI than with the β subunit. SPR revealed that PF had a strong affinity interaction with FcϵRI α subunit and the K_D value was (7.08 ± 0.97) e-6 M. Our findings revealed that PF inhibited anaphylactic responses in vivo and in vitro, and it can be considered a novel FcϵRI inhibitor for preventing MC-related allergic diseases.

Environmental and infrastructural effects on respiratory disease exacerbation: a LBSN and ANN-based spatio-temporal modelling

Owing to the rise in population, lifestyle changes, high traffic rates in urban areas and environmental pollution, respiratory diseases have become much more prevalent on both regional and urban scales. Respiratory diseases affect over 300 million people worldwide and are thus among the major threats to humans' general well-being. The identification of underlying factors and the specification of accompanying risk areas for the temporal exacerbation of respiratory diseases are effective steps in managing the damage caused by such disorders. Here, we demonstrate a strategy for modelling the risk zone of respiratory diseases temporally, using a location-based social network (LBSN) and an artificial neural network (ANN). The main contribution of this paper is to consider the environmental and infrastructural factors and identify their relationships with the geographical locations of respiratory attacks. The study also utilizes Telegram, which is the most popular and conventional social media platform, in order to observe temporal changes in the location of respiratory attacks in Iran, in the form of a developed Telegram bot known as @respiratoryassociation. The relations between the factors behind and the location of respiratory attacks are determined using a multilayer perceptron (MLP) ANN. All the required data have been collected on a daily basis over a 5-year period from December 2013 to December 2018 in Tehran, Iran. The results indicated air pollution, especially pollution from carbon monoxide (CO) and suspended particulate matter (PM) as the most decisive factors. Following air pollution, the amount of exposure to the polluted area was determined as the second most decisive factor, which in turn increased as a result of escalations in traffic jams. Land use was determined as the third most decisive factor. Furthermore, the results revealed that the ANN performed satisfactorily, implying that the model can be used to examine the spatio-temporal behaviour of the time series of respiratory diseases with respect to environmental and infrastructural factors.

Urban-associated diseases: Candidate diseases, environmental risk factors, and a path forward

BACKGROUND

Cities are home to over half the global population; that proportion is expected to rise to 70% by mid-century. The urban environment differs greatly from that in which humans evolved, with potentially important consequences for health. Rates for allergic, inflammatory and auto-immune diseases appear to rise with urbanization and be higher in the more urbanized nations of the world which has led some to suggest that cities promote the occurrence of these diseases. However, there are no syntheses outlining what urban-associated diseases are and what characteristics of cities promote their occurrence.

OBJECTIVES

To synthesize the current understanding of "urban-associated diseases", and discover the common, potentially modifiable features of cities that may be driving these associations.

METHODS

We focus on any diseases that have been associated with cities or are particularly prominent in today's urban societies. We draw on expertise across diverse health fields to examine the evidence for urban connections and drivers.

DISCUSSION

We found evidence for urban associations across allergic, auto-immune, inflammatory, lifestyle and infectious disease categories. Some conditions (e.g. obesity and diabetes) have complex relationships with cities that have been insufficiently explored. Other conditions (e.g. allergies and asthma) have more evidence demonstrating their relationship with cities and the mechanisms driving that association. Unsurprisingly, air pollution was the characteristic of cities most frequently associated with disease. Other identified urban risk factors are not as widely known: altered microbial exposure and a disconnect from environmental microbiomes, vitamin D deficiency, noise and light pollution, and a transient, over-crowded, impoverished population. However, many complexities and caveats to these relationships beg clarification; we highlight the current knowledge gaps and outline ways to fill those gaps. Identifying urban-associated diseases and their drivers will allow us to prepare for the urban-disease burden of the future and create healthy cities that mitigate that disease burden.

The "envirome" and what the practitioner needs to know about it

OBJECTIVE

This review on the "envirome" focuses on pollution, microbial, and social stressor elements of the environment that may impact development or expression of allergic diseases.

DATA SOURCES

Peer-reviewed publications on the impact of environmental factors indexed in PubMed were the primary data source for this review.

STUDY SELECTIONS

The primary search strategy for this review employed cross-referencing asthma, atopic dermatitis, and immunoglobulin E (IgE) against pollution (ozone, particulate matter, nitrogen oxides, tobacco smoke), microbial exposures (farm exposure, microbiome, infection, antibiotic use) and psychosocial stressors, with emphasis on results in the past 5 years, with inclusion of key seminal articles or comprehensive reviews.

RESULTS

Air pollution is a clear cause of allergic disease exacerbation, with increasing recognition that pollutant exposure increases risk of allergic disease. Microbial exposures and maternal and child stress also modulate development and expression of allergic disease. Early life exposures are especially critical periods during which all of these factors have notable impacts on allergic disease.

CONCLUSION

Nonallergenic environmental factors are important modulators and adjuvants for development of allergic disease, with early life exposures being especially important. Development and validation of interventions directed toward these factors during early life is a significant opportunity for primary prevention of allergic disease.

Vilnius Declaration on chronic respiratory diseases: multisectoral care pathways embedding guided self-management, mHealth and air pollution in chronic respiratory diseases

Background

Over 1 billion people suffer from chronic respiratory diseases such as asthma, COPD, rhinitis and rhinosinusitis. They cause an enormous burden and are considered as major non-communicable diseases. Many patients are still uncontrolled and the cost of inaction is unacceptable. A meeting was held in Vilnius, Lithuania (March 23, 2018) under the patronage of the Ministry of Health and several scientific societies to propose multisectoral care pathways embedding guided self-management, mHealth and air pollution in selected chronic respiratory diseases (rhinitis, chronic rhinosinusitis, asthma and COPD). The meeting resulted in the Vilnius Declaration that was developed by the participants of the EU Summit on chronic respiratory diseases under the leadership of Euforea.

Conclusion

The Vilnius Declaration represents an important step for the fight against air pollution in chronic respiratory diseases globally and has a clear strategic relevance with regard to the EU Health Strategy as it will bring added value to the existing public health knowledge.