Preventing carbon nanoparticle-induced lung inflammation reduces antigen-specific sensitization and subsequent allergic reactions in a mouse model

Lung proteomic and metabolomic changes induced by carbon black nanoparticles and high humidity in a mouse asthma model

Allergic asthma is a significant international concern in respiratory health, which can be exacerbated by the increasing levels of non-allergenic pollutants. This rise in airborne pollutants is a primary driver behind the growing prevalence of asthma, posing a health emergency. Additionally, climatic risk factors can contribute to the onset and progression of asthma. Understanding the complex interplay between pollution, climate, and asthma induction is crucial to elucidate how environmental changes intensify asthma. In this study, we investigated the proteomic and metabolomic changes in the lungs of a mouse asthma model following co-exposure to carbon black nanoparticles and high humidity, which represent airborne and climatic factors, respectively. An asthma model was established using ovalbumin, and mice were intratracheally instilled with 15 or 30 μg/kg of carbon black and simultaneously exposed to either 70% or 90% relative humidity. Protein and metabolite profiles from the lung were used to analyze the most significantly changed clusters, and potential biomarkers and enriched pathways were identified to dissect the adverse effects of the two risk factors. The lung proteome and metabolome are significantly altered by the co-exposure, with the effects modulated by carbon black concentration and humidity level. This study proposes 10 proteins and 18 metabolites as candidate biomarkers. The significantly enriched KEGG pathways include one protein pathway (primary immunodeficiency) and six metabolic pathways (ABC transporters, nucleotide metabolism, Parkinson's disease, purine metabolism, choline metabolism in cancer, and biosynthesis of cofactors). A joint proteomic and metabolomic analysis identifies five common pathways across both omics, namely, ABC transporters, central carbon metabolism in cancer, EGFR tyrosine kinase inhibitor resistance, glioma, and NF-kappa B signaling pathway, disturbed by the co-exposure. We provide a multi-omic basis for the health risk assessment and management of co-exposures to environmental risk factors.

A molecular toxicological study to explore potential health risks associated with ultrafine particle exposure in cold and humid indoor environments

Environmental pollutants including ultrafine particulate matter (UFPs) and adverse meteorological conditions pose significant public health impacts, particularly affecting respiratory health. This study aims to elucidate the synergistic effects of cold-humid conditions and UFPs exposure on respiratory health, utilizing Carbon Black Nanoparticles (CB-NPs) as surrogates for UFPs. Through comprehensive lung function tests, histopathological examinations, and biomarker analyses, this research focuses on the modulation of oxidative stress signaling pathways and NF-κB activation. Male Balb/c mice were exposed to specific concentrations of CB-NPs (30-50 nm in diameter, 0.184 mg/(kg·day)) in a controlled environmental chamber mimicking cold (10°C/14°C) and humid (90 % RH) conditions over three weeks. The results indicate that exposure to CB-NPs alone increased lung function, oxidative stress (ROS, GSH, MDA), inflammation (IL-6, TNF-α, IL-1β), apoptosis (Caspase 3, Caspase 8, Caspase 9), and histopathological alterations in lung tissue. Furthermore, these effects were notably more severe under combined exposure with cold-humid conditions. These results suggest that the adverse effects of pollutants are not solely concentration-dependent but are exacerbated by specific environmental contexts. It is evident that Vitamin E (100 mg/kg/day) can attenuate these adverse effects, underscoring its potential as a protective agent against environmental stressor-induced air pollutants and cold humid conditions. Our findings suggest that the synergistic effects of environmental factors and pollutant exposure significantly impact respiratory health, providing valuable insights for the design of healthier indoor environments and the development of strategies to mitigate these risks.

Sugar beet molasses: a sweet solution for ectoine production by Nesterenkonia sp

Ectoine, a biologically significant compound, was successfully produced by a strain of bacteria capable of utilizing sucrose. In a ground-breaking approach, we harnessed the potential of sugar beet molasses, a by-product rich in sucrose, amino acid, and vitamins, as a growth medium for this purpose. Through meticulous investigation, we identified the ideal conditions for maximizing ectoine synthesis. This remarkable milestone was reached by introducing only 1 g of (NH₄)₂SO₄ and 5 mL of molasses per liter, maintaining a pH level of 8.0, upholding a 7.5% NaCl concentration, employing agitation at 120 rpm, and sustaining a temperature of 30 °C. This study marks a pioneering endeavour as it represents the first instance where molasses has been effectively employed to produce ectoine through the cultivation of Nesterenkonia sp. We showcased the production of 75.56 g of the valuable compound ectoine utilizing 1 L of waste molasses with this specific bacterial strain. These findings hold tremendous promise, not only in terms of resource utilization but also for the potential applications of ectoine in various biological contexts.

Ectoine production from a novel bacterial strain and high-purity purification with a cost-effective and single-step method

This study marks the exploration into the production of ectoine, a valuable compound with significant potential as an antioxidant, osmoprotectant, anti-inflammatory agent, and stabilizer of cell membranes, proteins, and DNA integrity. Our focus centred on investigating the presence of ectoine and optimizing its production by the novel ectoine producer bacterial strain, Piscibacillus halophilus. For the optimization of ectoine production the effects of carbon and nitrogen sources, salt, pH, agitation and incubation period were optimized by one-factor-at-a-time. We started with an initial ectoine content of 46.92 mg/L, and through a series of optimization processes, we achieved a remarkable increase, resulting in an ectoine content of 1498.2 mg/L. The bacterial species P. halophilus achieved its highest ectoine production after 48 h of incubation, with conditions set at 10 % (w/v) salinity, pH of 7.50, and an agitation speed of 160 rpm. These precise conditions were found to be the most favourable for maximizing ectoine production by this strain. Besides, we have achieved successful purification of ectoine from the crude extract through a streamlined single-step process. This purification method has delivered an exceptional level of purity, surpassing 99.15 %, and an impressive yield of over 99 %. Importantly, we accomplished this using readily available and cost-effective strong acids (HCl) and strong bases (NaOH) to arrange pH gradients. The use of acid and base in the purification process of ectoine reflects an innovative and sustainable methodology.

Recent advances in production and applications of ectoine, a compatible solute of industrial relevance

Extremophilic bacteria growing in saline ecosystems are potential producers of biotechnologically important products including compatible solutes. Ectoine/hydroxyectoine are two such solutes that protect cells and associated macromolecules from osmotic, heat, cold and UV stress without interfering with cellular functions. Since ectoine is a high value product, overviewing strategies for improving yields become relevant. Screening of natural isolates, use of inexpensive substrates and response surface methodology approaches have been used to improve bioprocess parameters. In addition, genome mining exercises can aid in identifying hitherto unreported microorganisms with a potential to produce ectoine that can be exploited in the future. Application wise, ectoine has various biotechnological (protein protectant, membrane modulator, DNA protectant, cryoprotective agent, wastewater treatment) and biomedical (dermatoprotectant and in overcoming respiratory and hypersensitivity diseases) uses. The review summarizes current updates on the potential of microorganisms in the production of this industrially relevant metabolite and its varied applications.

Toxicity and Mechanisms of Engineered Nanoparticles in Animals with Established Allergic Asthma

Asthma is a chronic respiratory disease that is highly sensitive to environmental pollutants, including engineered nanoparticles (NPs). Exposure to NPs has become a growing concern for human health, especially for susceptible populations. Toxicological studies have demonstrated strong associations between ubiquitous NPs and allergic asthma. In this review, we analyze articles that focus on adverse health effects induced by NPs in animal models of allergic asthma to highlight their critical role in asthma. We also integrate potential mechanisms that could stimulate and aggravate asthma by NPs. The toxic effects of NPs are influenced by their physicochemical properties, exposure dose, duration, route, as well as the exposure order between NPs and allergens. The toxic mechanisms involve oxidative stress, various inflammasomes, antigen presenting cells, immune cells, and signaling pathways. We suggest that future research should concentrate on establishing standardized models, exploring mechanistic insights at the molecular level, assessing the combined effects of binary exposures, and determining safe exposure levels of NPs. This work provides concrete evidence of the hazards posed by NPs in animals with compromised respiratory health and supports the modifying role of NPs exposure in allergic asthma.

Effect of NO2 exposure on airway inflammation and oxidative stress in asthmatic mice

Nitrogen dioxide (NO₂) is a widespread air pollutant. Epidemiological evidence indicates that NO₂ is associated with an increase of incidence rate and mortality of asthma, but its mechanism is still unclear. In this study, we exposed mice to NO₂ (5 ppm, 4 h per day for 30 days) intermittently to investigate the development and potential toxicological mechanisms of allergic asthma. We randomly assigned 60 male Balb/c mice to four groups: saline control, ovalbumin (OVA) sensitization, NO₂ alone, and OVA+NO₂ groups. The involved mechanisms were found from the perspective of airway inflammation and oxidative stress. The results showed that NO₂ exposure could aggravate lung inflammation in asthmatic mice, and airway remodeling was characterized by significant thickening of the airway wall and infiltration of inflammatory cells. Moreover, NO₂ would aggravate the airway hyperresponsiveness (AHR), which is characterized by significantly elevated inspiratory resistance (Ri) and expiratory resistance (Re), as well as decreased dynamic lung compliance (Cldyn). In addition, NO₂ exposure promoted pro-inflammatory cytokines (IL-6 and TNF-α) and serum immunoglobulin (IgE) production. The imbalance of Th1/Th2 cell differentiation (IL-4 increased, IFN-γ reduced, IL-4/IFN-γ significantly increased) played a key role in the inflammatory response of asthma under NO₂ exposure. In a nutshell, NO₂ exposure could promote allergic airway inflammation and increase asthma susceptibility. The levels of ROS and MDA among asthmatic mice exposed to NO₂ increased significantly, while GSH levels sharply decreased. These findings may provide better toxicological evidence for the mechanisms of allergic asthma risk due to NO₂ exposure.

Nanoparticle formulations: A smart era of advanced treatment with nanotoxicological imprints on the human body

In the modern era, nanoparticles are the preferred dosage form, and maximum research is going on in the field of nanoparticle formulations. But as they are so small, nanoparticles are able to slip through the body's defenses and cause damage to the organs and tissues deep inside. In recent years, most researchers have focused solely on the therapeutic value of drugs or, at times, the performance of dosage forms, but few have given toxicity studies equal weight in their research. This review demonstrates that nanoparticle formulations are not suitable from a safety standpoint. So, researchers should be focused on alternative formulations like nanoemulsion, nanogel, and other liquids as well as semisolid formulations.

Nanomaterial-induced toxicity in pathophysiological models representative of individuals with pre-existing medical conditions

The integration of nanomaterials (NMs) into an ever-expanding number of daily used products has proven to be highly desirable in numerous industries and applications. Unfortunately, the same "nano" specific physicochemical properties, which make these materials attractive, may also contribute to hazards for individuals exposed to these materials. In 2021, it was estimated that 7 out of 10 deaths globally were accredited to chronic diseases, such as chronic liver disease, asthma, and cardiovascular-related illnesses. Crucially, it is also understood that a significant proportion of global populace numbering in the billions are currently living with a range of chronic undiagnosed health conditions. Due to the significant number of individuals affected, it is important that people suffering from chronic disease also be considered and incorporated in NM hazard assessment strategies. This review examined and analyzed the literature that focused on NM-induced adverse health effects in models which are representative of individuals exhibiting pre-existing medical conditions with focus on the pulmonary, cardiovascular, hepatic, gastrointestinal, and central nervous systems. The overall objective of this review was to outline available data, highlighting the important role of pre-existing disease in NM-induced toxicity with the aim of establishing a weight of evidence approach to inform the public on the potential hazards posed by NMs in both healthy and compromised persons in general population.

Identification of novel halophilic/halotolerant bacterial species producing compatible solutes

Ectoine and hydroxyectoine are compatible solutes with enormous potential for use in the medical and cosmetic industries. Considering the excellent osmoprotective properties of these compatible solutes, we investigate the presence of four compatible solutes (ectoine, hydroxyectoine, proline, and glutamic acid) quantitatively by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in forty-five halophilic/halotolerant bacterial isolates. We determined ectoine production by Marinibacillus sp., Nesterenkonia xinjiangensis, Halobacillus sp., Bacillus patagoniensis, Virgibacillus picturae, Halomonas neptunia, Bacillus patagoniensis, Gracilibacillus sp., Thalassobacillus devorans, Microbacterium sp., Nesterenkonia sp., and Bacillus agaradhaerens, and this production was NaCl dependent. Additionally, the production of hydroxyectoine was observed in six bacterial isolates (Nesterenkonia xinjiangensis, Halobacillus sp., Halomonas neptunia, Thalassobacillus devorans, Nesterenkonia sp., and Bacillus agaradhaerens) which was NaCl and temperature dependent. The study identified new bacterial isolates producing ectoine or hydroxyectoine. While the ectoine production in many different Bacillus members and a few Nesterenkonia have been documented before, ectoine production by Bacillus patagoniensis and Nesterenkonia xinjiangensis has not been shown so far. Further, ectoine production by a member of the genus Thalassobacillus (Thalassobacillus devorans) was demonstrated experimentally for the first time. The findings reported in the study may serve as a basis for the large-scale production of ectoine and hydroxyectoine in the future.

Effects of carbon black nanoparticles and high humidity on the lung metabolome in Balb/c mice with established allergic asthma

In respiratory diseases, the induction of allergic asthma has gradually aroused public concerns. Co-exposures of environmental risk factors such as nanoparticles and high humidity could play important roles in the development of allergic asthma. However, the relevant researches are still lacking and the involved mechanisms, especially metabolic changes, remain unclear. We took the lead in studying the combined induction effect and underlying mechanisms of carbon black nanoparticles (CB NPs) and high humidity on allergic asthma. In this work, murine models of allergic asthma were established with ovalbumin under the single and combined exposures of 15 μg/kg CB NPs and 90% relative humidity. The two risk factors, particularly their co-exposure, exhibited adjuvant effect on airway hyperresponsiveness, remodeling, and inflammation in Balb/c mice. Untargeted metabolomics identified the potential biomarkers in lung for asthma occurrence and for asthma exacerbation caused by CB NPs and high humidity. The significantly dysregulated metabolic pathways in asthmatic mice were proposed, and the disturbed metabolic pathways under the exposures of CB NPs and/or high humidity were mainly implicated in asthma symptoms. This work sheds light on the understanding for health risks of NP pollutions and high environmental humidity and contributes to useful biomarker identification and asthma control.

Development of allergic asthma and changes of intestinal microbiota in mice under high humidity and/or carbon black nanoparticles

In respiratory diseases, the induction of allergic asthma is one of the hottest issues of international concern. The adjuvant effect of air pollutants including nanoparticles (NPs) has be pointed out to facilitate the occurrence and development of allergic asthma. This work studied the development of allergic asthma upon exposures of carbon black nanoparticles (CB NPs, 30-50 nm) and/or high environmental humidity (90% relative humidity). The mechanisms involved were investigated from perspectives of the activation of oxidative stress and transient receptor potential vanilloid 1 (TRPV1) pathways and the alteration in intestinal microbiota. Both high humidity and CB NPs aggravated the airway hyperreactivity, remodeling, and inflammation in Balb/c mice sensitized by ovalbumin. The co-exposure of these two risk factors exhibited adjuvant effect on the development of asthma likely through activating oxidative stress pathway and TRPV1 pathway and then facilitating type I hypersensitivity. Additionally, exposures of high humidity and/or CB NPs reduced the richness of intestinal microbes, altered microbial community composition, and weakened corresponding biological functions, which may interact with the development of asthma. The findings will add new toxicological knowledge to the health risk assessment and management of co-exposures of NPs and other risk factors in the environment.

Topical Ectoine Application in Children and Adults to Treat Inflammatory Diseases Associated with an Impaired Skin Barrier: A Systematic Review

Introduction

Inflammatory skin diseases are a significant burden on affected patients. Inflammation is caused by various stress factors to the epidermis resulting in, e.g., dryness, redness, and pruritus. Emollients are used in basic therapy to restore the natural skin barrier and relieve symptoms. A systematic review was performed to evaluate the efficacy and safety of ectoine-containing topical formulations in inflammatory skin diseases characterized by an impaired skin barrier.

Methods

A systematic review was carried out in PubMed, the Cochrane Library, and Microsoft Academic up to October 2021. Inclusion criteria were ectoine-containing topical formulations (creams, emollients) used for (adjuvant) therapy of inflammatory skin diseases. Clinical studies of any design published in any language were included.

Results

A total of 230 references were screened for eligibility, of which six were selected for inclusion in the review (five studies on atopic dermatitis and one study on prevention and management of retinoid dermatitis). The application of topical formulations containing 5.5–7.0% ectoine positively influenced skin dryness and, consequently, pruritus and dermatitis-specific scores in patients with atopic dermatitis. Especially in infants and children, who belong to the most frequently affected group, the formulations were well-tolerated when applied for up to 4 weeks. In studies where ectoine was used as an adjuvant therapy, application was associated with a decreased need for pharmacological therapy and also improved the effectiveness of, e.g., topical corticosteroids. In patients undergoing isotretinoin therapy, ectoine was as effective as dexpanthenol in reducing retinoid dermatitis or improving symptoms.

Conclusion

Ectoine is an effective natural substance with an excellent tolerability and safety profile, representing a beneficial alternative as basic therapy or to increase the efficacy of the pharmacological treatment regimen for patients with inflammatory skin diseases, including infants and children.

The Effectiveness of the Bacteria Derived Extremolyte Ectoine for the Treatment of Allergic Rhinitis

Nonpharmacological therapies with a good tolerability and safety profile are of interest to many patients with allergic rhinitis, as a relevant proportion of them have reservations about guideline-concordant pharmacological therapies due to their local irritations and side effects. Ectoine is a bacterial-derived extremolyte with an ability to protect proteins and biological membranes against damage caused by extreme conditions of salinity, drought, irradiation, pH, and temperature. Evidence from preclinical and clinical studies attests its effectiveness in the treatment of several inflammatory diseases, including allergic rhinitis. In this review, we analyzed 14 recent clinical trials investigating ectoine nasal spray in patients with allergic rhinitis and/or conjunctivitis, including sensitive patient groups like children or pregnant women. Some studies investigated monotherapy with ectoine; others investigated combination therapy of ectoine and an antihistamine or a corticosteroid. Analysis of the study results demonstrated that patients with mild-to-moderate symptoms of allergic rhinitis can be successfully treated with ectoine-containing nasal spray. When applied as monotherapy, ectoine exerted noninferior effects compared to first-line therapies such as antihistamines and cromoglicic acid. Using ectoine as an add-on therapy to antihistamines or intranasal glucocorticosteroids accelerated symptom relief by days and improved the level of symptom relief. Importantly, concomitant treatment with ectoine was proven beneficial in a group of difficult-to-treat patients suffering from moderate-to-severe rhinitis symptoms. Taken together, the natural substance ectoine represents a viable alternative for allergic rhinitis and conjunctivitis patients who wish to avoid local reactions and side effects associated with pharmacological therapies.

Ectoine in the Treatment of Irritations and Inflammations of the Eye Surface

The ocular surface is facing various unspecific stress factors resulting in irritation and inflammation of the epithelia, causing discomfort to the patients. Ectoine is a bacteria-derived extremolyte with the ability to protect proteins and biological membranes from damage caused by extreme environmental conditions like heat, UV-light, high osmolarity, or dryness. Evidence from preclinical and clinical studies attest its effectiveness in treating several epithelium-associated inflammatory diseases, including the eye surface. In this review, we analysed 16 recent clinical trials investigating ectoine eye drops in patients with allergic conjunctivitis or with other unspecific ocular inflammations caused by e.g. ophthalmic surgery. Findings from these studies were reviewed in context with other published work on ectoine. In summary, patients with irritations and unspecific inflammations of the ocular surface have been treated successfully with ectoine-containing eye drops. In these patients, significant improvement was observed in ocular symptoms of allergic rhinoconjunctivitis, postoperative secondary dry eye syndrome, or ocular reepithelisation after surgery. Using ectoine as an add-on therapy to antihistamines, in allergy patients accelerated symptom relief by days, and its use as an add-on to antibiotics resulted in faster wound closure. Ectoine is a natural substance with an excellent tolerability and safety profile thus representing a helpful alternative for patients with inflammatory irritation of the ocular surface, who wish to avoid local reactions and side effects associated with pharmacological therapies or wish to increase the efficacy of standard treatment regimen.

Mechanisms of Particles in Sensitization, Effector Function and Therapy of Allergic Disease

Humans have always been in contact with natural airborne particles from many sources including biologic particulate matter (PM) which can exhibit allergenic properties. With industrialization, anthropogenic and combustion-derived particles have become a major fraction. Currently, an ever-growing number of diverse and innovative materials containing engineered nanoparticles (NPs) are being developed with great expectations in technology and medicine. Nanomaterials have entered everyday products including cosmetics, textiles, electronics, sports equipment, as well as food, and food packaging. As part of natural evolution humans have adapted to the exposure to particulate matter, aiming to protect the individual's integrity and health. At the respiratory barrier, complications can arise, when allergic sensitization and pulmonary diseases occur in response to particle exposure. Particulate matter in the form of plant pollen, dust mites feces, animal dander, but also aerosols arising from industrial processes in occupational settings including diverse mixtures thereof can exert such effects. This review article gives an overview of the allergic immune response and addresses specifically the mechanisms of particulates in the context of allergic sensitization, effector function and therapy. In regard of the first theme (i), an overview on exposure to particulates and the functionalities of the relevant immune cells involved in allergic sensitization as well as their interactions in innate and adaptive responses are described. As relevant for human disease, we aim to outline (ii) the potential effector mechanisms that lead to the aggravation of an ongoing immune deviation (such as asthma, chronic obstructive pulmonary disease, etc.) by inhaled particulates, including NPs. Even though adverse effects can be exerted by (nano)particles, leading to allergic sensitization, and the exacerbation of allergic symptoms, promising potential has been shown for their use in (iii) therapeutic approaches of allergic disease, for example as adjuvants. Hence, allergen-specific immunotherapy (AIT) is introduced and the role of adjuvants such as alum as well as the current understanding of their mechanisms of action is reviewed. Finally, future prospects of nanomedicines in allergy treatment are described, which involve modern platform technologies combining immunomodulatory effects at several (immuno-)functional levels.

Samsum ant venom modulates the immune response and redox status at the acute toxic dose in vivo

BACKGROUND

Ant venoms express surface molecules that participate in antigen presentation involving pro- and anti-inflammatory cytokines. This work aims to investigate the expression of MHC-II, CD80 and CD86 on the polymorphonuclear cells (PMNs) in rats injected with samsum ant venom (SAV).

METHODS

Rats were divided into three groups - control, SAV-treated (intraperitoneal route, 600 μg/kg), and SAV-treated (subcutaneous route, 600 μg/kg). After five doses, animals were euthanized and samples collected for analysis.

RESULTS

The subcutaneous SAV-trated rats presented decreased levels of glutathione with increased cholesterol and triglyceride levels. Intraperitoneal SAV-treated animals displayed significantly reduced concentrations of both IFN-γ and IL-17 in comparison with the control group. However, intraperitoneal and subcutaneous SAV-treated rats were able to upregulate the expressions of MHC-II, CD80 and CD86 on PMNs in comparison with the control respectively. The histological examination showed severe lymphocyte depletion in the splenic white pulp of the intraperitoneal SAV-injected rats.

CONCLUSION

Stimulation of PMNs by SAV leads to upregulation of MHC-II, CD 80, and CD 86, which plays critical roles in antigen presentation and consequently proliferation of T-cells. Subcutaneous route was more efficient than intraperitoneal by elevating MHC-II, CD80 and CD86 expression, disturbing oxidative stability and increasing lipogram concentration.

Role of chemical composition and redox modification of poorly soluble nanomaterials on their ability to enhance allergic airway sensitisation in mice

BACKGROUND

Engineered nanoparticles (NPs) have been shown to enhance allergic airways disease in mice. However, the influence of the different physicochemical properties of these particles on their adjuvant properties is largely unknown. Here we investigate the effects of chemical composition and redox activity of poorly soluble NPs on their adjuvant potency in a mouse model of airway hypersensitivity.

RESULTS

NPs of roughly similar sizes with different chemical composition and redox activity, including CeO₂, Zr-doped CeO₂, Co₃O₄, Fe-doped Co₃O₄(using Fe₂O₃ or Fe₃O₄) and TiO₂ NPs, all showed adjuvant activity. OVA induced immune responses following intranasal exposure of BALB/c mice to 0.02% OVA in combination with 200 μg NPs during sensitization (on day 1, 3, 6 and 8) and 0.5% OVA only during challenge (day 22, 23 and 24) were more pronounced compared to the same OVA treatment regime without NPs. Changes in OVA-specific IgE and IgG1 plasma levels, differential cell count and cytokines in bronchoalveolar lavage fluid (BALF), and histopathological detection of mucosa cell metaplasia and eosinophil density in the conducting airways were observed. Adjuvant activity of the CeO₂ NPs was primarily mediated via the Th2 response, while that of the Co₃O₄ NPs was characterised by no or less marked increases in IgE plasma levels, BALF IL-4 and IL-5 concentrations and percentages of eosinophils in BALF and more pronounced increases in BALF IL-6 concentrations and percentages of lymphocytes in BALF. Co-exposure to Co₃O₄ NPs with OVA and subsequent OVA challenge also induced perivascular and peribronchiolar lymphoid cell accumulation and formation of ectopic lymphoid tissue in lungs. Responses to OVA combined with various NPs were not affected by the amount of doping or redox activity of the NPs.

CONCLUSIONS

The findings indicate that chemical composition of NPs influences both the relative potency of NPs to exacerbate allergic airway sensitization and the type of immune response. However, no relation between the acellular redox activity and the observed adjuvant activity of the different NPs was found. Further research is needed to pinpoint the precise physiological properties of NPs and biological mechanisms determining adjuvant activity in order to facilitate a safe-by-design approach to NP development.

Topical Ectoine: A Promising Molecule in the Upper Airways Inflammation-A Systematic Review

To date, topical therapies guarantee a better delivery of high concentrations of pharmacologic agents to the mucosa of the upper airways (UA). Recently, topical administration of ectoine has just been recognized as adjuvant treatment in the Allergic Rhinitis (AR) and Rhinosinusitis (ARS). The aim of this work is to review the published literature regarding all the potential therapeutic effects of ectoine in the acute and chronic inflammatory diseases of UA. Pertinent studies published without temporal limitation were selected searching on MEDLINE the following terms: “ectoine” and “nasal spray,” “oral spray,” “upper respiratory tract infections,” “rhinosinusitis,” “rhinitis,” “rhinoconjunctivitis,” “pharyngitis,” and “laryngitis.” At the end of our selection process, six relevant publications were included: two studies about the effect of ectoine on AR, one study about ARS, one study about rhinitis sicca anterior, and two studies about acute pharyngitis and/or laryngitis. Due to its moisturizing and anti-inflammatory properties, topical administration of ectoine could play a potential additional role in treatment of acute and chronic inflammatory diseases of UA, in particular in the management of sinonasal conditions improving symptoms and endoscopic findings. However, these results should be viewed cautiously as they are based on a limited number of studies; some of them were probably underpowered because of their small patient samples.

Cellular Toxicity and Immunological Effects of Carbon-based Nanomaterials

BACKGROUND

Carbon nanomaterials are a growing family of materials featuring unique physicochemical properties, and their widespread application is accompanied by increasing human exposure.

MAIN BODY

Considerable efforts have been made to characterize the potential toxicity of carbon nanomaterials in vitro and in vivo. Many studies have reported various toxicology profiles of carbon nanomaterials. The different results of the cytotoxicity of the carbon-based materials might be related to the differences in the physicochemical properties or structures of carbon nanomaterials, types of target cells and methods of particle dispersion, etc. The reported cytotoxicity effects mainly included reactive oxygen species generation, DNA damage, lysosomal damage, mitochondrial dysfunction and eventual cell death via apoptosis or necrosis. Despite the cellular toxicity, the immunological effects of the carbon-based nanomaterials, such as the pulmonary macrophage activation and inflammation induced by carbon nanomaterials, have been thoroughly studied. The roles of carbon nanomaterials in activating different immune cells or inducing immunosuppression have also been addressed.

CONCLUSION

Here, we provide a review of the latest research findings on the toxicological profiles of carbon-based nanomaterials, highlighting both the cellular toxicities and immunological effects of carbon nanomaterials. This review provides information on the overall status, trends, and research needs for toxicological studies of carbon nanomaterials.

The Toxicology of Engineered Nanomaterials in Asthma

PURPOSE OF REVIEW

The explosive growth of the nanotechnology industry has necessitated the examination of engineered nanomaterials (ENMs) for their toxicity. The unique properties that make ENMs useful also make them a health risk, and individuals with pre-existing diseases such as asthma are likely more susceptible. This review summarizes the current literature on the ability of ENMs to both exacerbate and directly cause asthma.

RECENT FINDINGS

Recent studies highlight the ability of metal nanoparticles (NPs) and carbon nanotubes (CNTs) to not only exacerbate pre-existing asthma in animal models but also initiate allergic airway disease directly. CNTs alone are shown to cause airway mucus production, elevated serum IgE levels, and increased T_H2 cytokine levels, all key indicators of asthma. The ability of ENMs to modulate the immune response in asthma varies depending on their physicochemical properties and exposure timing. CNTs consistently exacerbate asthma, as do Ni and TiO₂ NPs, whereas some NPs like Au attenuate asthma. Evidence is strong that ENMs can contribute to allergic airway disease; however, more work is required to determine their mechanisms, and more epidemiological studies are needed to validate results from animal models.

Ectoine lozenges in the treatment of acute viral pharyngitis: a prospective, active-controlled clinical study

PURPOSE

Acute pharyngitis is an uncomfortable disorder mostly caused by viruses and for which antibiotics are unwarranted. This study compared lozenges containing ectoine, a natural extremolyte, with hyaluronic acid lozenges and hypertonic saline gargle for symptomatic treatment of acute viral pharyngitis.

METHODS

This prospective, controlled clinical study, recruited 90 patients with moderate-to-severe pharyngitis symptoms who chose to use either ectoine (n = 35), hyaluronic acid (n = 35), or saline gargle (n = 20). Patients applied their 7-day treatment from the inclusion visit (V1) until the end-of-study visit (V2). Patients' pharyngitis symptoms, general health, general treatment effectiveness and tolerability, and patient compliance were assessed by investigators and patients.

RESULTS

The sum score for three primary symptoms (pain on swallowing, urge to cough, and hoarseness) decreased by 79.5% (ectoine), 72.2% (hyaluronic acid), and 44.8% (saline gargle). Both lozenges were significantly superior to saline gargle (P < 0.05). Regarding general health improvement, ectoine was significantly superior to saline gargle (72.5% vs. 45.2%, P < 0.05), but hyaluronic acid (63.3%) was not. At V2, 65.7% of patients receiving ectoine reported "very good" general health vs. 48.6% of those receiving hyaluronic acid and 20.0% using saline gargle. Ectoine was significantly superior (P < 0.05) to both hyaluronic acid and saline gargle in terms of tolerability and patient compliance. No patients taking ectoine reported unpleasant sensations while applying their treatment, whereas almost half of patients using hyaluronic acid lozenges and saline gargle did.

CONCLUSION

Treatment with ectoine lozenges significantly relieves moderate-to-severe symptoms of acute viral pharyngitis and is more effective and tolerable than treatments with hyaluronic acid lozenges and hypertonic saline gargle.

Ectoine-Containing Inhalation Solution versus Saline Inhalation Solution in the Treatment of Acute Bronchitis and Acute Respiratory Infections: A Prospective, Controlled, Observational Study

Purpose

This study investigated an inhalation solution containing ectoine, a bacterial-derived extremolyte, for the treatment of acute bronchitis and acute respiratory infections in comparison with saline inhalation solution.

Methods

This prospective, controlled, observational study comprised an inclusion visit (day 1), a final visit (day 7), and a follow-up questionnaire (day 17). The treatment itself was administered from day 1 to day 7. The Bronchitis Severity Score, patients' general health, general effectiveness of the treatment, tolerability, and adverse events were compared between two groups.

Results

In total, 135 patients were recruited; 79 patients received ectoine inhalation solution and 56 saline inhalation solution. After treatment, symptom scores decreased significantly in both groups (P < 0.05); the reduction in symptom scores was slightly greater in the ectoine group than in the saline group. The first significant reduction in symptom scores (P < 0.05) occurred earlier in the ectoine group than in the saline group. The differences in the area under the curve for the symptoms of dyspnea and auscultation findings were significant in favor of ectoine (P < 0.05). After treatment, more patients and physicians in the ectoine group assessed their or their patients' condition as “completely recovered” or “greatly improved” than those in the saline group. Almost all patients and physicians assessed the tolerability of both treatments as “good” or “very good”.

Conclusions

Ectoine inhalation solution seems to be slightly more effective than saline inhalation solution for the treatment of acute bronchitis and acute respiratory infections.

Non-Canonical Activation of the Epidermal Growth Factor Receptor by Carbon Nanoparticles

The epidermal growth factor receptor (EGFR) is an abundant membrane protein, which is essential for regulating many cellular processes including cell proliferation. In our earlier studies, we observed an activation of the EGFR and subsequent signaling events after the exposure of epithelial cells to carbon nanoparticles. In the current study, we describe molecular mechanisms that allow for discriminating carbon nanoparticle-specific from ligand-dependent receptor activation. Caveolin-1 is a key player that co-localizes with the EGFR upon receptor activation by carbon nanoparticles. This specific process mediated by nanoparticle-induced reactive oxygen species and the accumulation of ceramides in the plasma membrane is not triggered when cells are exposed to non-nano carbon particles or the physiological ligand EGF. The role of caveolae formation was demonstrated by the induction of higher order structures of caveolin-1 and by the inhibition of caveolae formation. Using an in vivo model with genetically modified mice lacking caveolin-1, it was possible to demonstrate that carbon nanoparticles in vivo trigger EGFR downstream signaling cascades via caveolin-1. The identified molecular mechanisms are, therefore, of toxicological relevance for inhaled nanoparticles. However, nanoparticles that are intentionally applied to humans might cause side effects depending on this phenomenon.

Mechanistic insight into the impact of nanomaterials on asthma and allergic airway disease

Asthma is a chronic respiratory disease known for its high susceptibility to environmental exposure. Inadvertent inhalation of engineered or incidental nanomaterials is a concern for human health, particularly for those with underlying disease susceptibility. In this review we provide a comprehensive analysis of those studies focussed on safety assessment of different nanomaterials and their unique characteristics on asthma and allergic airway disease. These include in vivo and in vitro approaches as well as human and population studies. The weight of evidence presented supports a modifying role for nanomaterial exposure on established asthma as well as the development of the condition. Due to the variability in modelling approaches, nanomaterial characterisation and endpoints used for assessment in these studies, there is insufficient information for how one may assign relative hazard potential to individual nanoscale properties. New developments including the adoption of standardised models and focussed in vitro and in silico approaches have the potential to more reliably identify properties of concern through comparative analysis across robust and select testing systems. Importantly, key to refinement and choice of the most appropriate testing systems is a more complete understanding of how these materials may influence disease at the cellular and molecular level. Detailed mechanistic insight also brings with it opportunities to build important population and exposure susceptibilities into models. Ultimately, such approaches have the potential to more clearly extrapolate relevant toxicological information, which can be used to improve nanomaterial safety assessment for human disease susceptibility.

Ectoine as a promising protective agent in humans and animals

Ectoine is a compatible water molecule-binding solute (osmoprotectant) produced by several bacterial species in response to osmotic stress and unfavourable environmental conditions. This amino acid derivative can accumulate inside cells at high concentrations without interfering with natural processes and can protect the cell against radiation or osmotic stress. This brief review presents the current state of knowledge about the effects of ectoine on animals and focuses on its practical use for enzyme stabilisation, human skin protection, anti-inflammatory treatment, inhibitory effects in neurodegenerative diseases, and other therapeutic potential in human or veterinary medicine.

Reduction of neutrophilic lung inflammation by inhalation of the compatible solute ectoine: a randomized trial with elderly individuals

Background

Compatible solutes are natural substances that are known to stabilize cellular functions. Preliminary ex vivo and in vivo studies demonstrated that the compatible solute ectoine restores natural apoptosis rates of lung neutrophils and contributes to the resolution of lung inflammation. Due to the low toxicity and known compatibility of the substance, an inhalative application as an intervention strategy for humans suffering from diseases caused by neutrophilic inflammation, like COPD, had been suggested. As a first approach to test the feasibility and efficacy of such a treatment, we performed a population-based randomized trial.

Objective

The objective of the study was to test whether the daily inhalation of the registered ectoine-containing medical device (Ectoin^® inhalation solution) leads to a reduction of neutrophilic cells and interleukin-8 (IL-8) levels in the sputum of persons with mild symptoms of airway disease due to lifelong exposure to environmental air pollution.

Methods

A double-blinded placebo-controlled trial was performed to study the efficacy and safety of an ectoine-containing therapeutic. Prior to and after both inhalation periods, lung function, inflammatory parameters in sputum, serum markers, and quality-of-life parameters were determined.

Results

While the other outcomes revealed no significant effects, sputum parameters were changed by the intervention. Nitrogen oxides (nitrate and nitrite) were significantly reduced after ectoine inhalation with a mean quotient of 0.65 (95% confidence interval 0.45–0.93). Extended analyses considering period effects revealed that the percentage of neutrophils in sputum was significantly lower after ectoine inhalation than in the placebo group (P=0.035) even after the washout phase.

Conclusion

The current study is the first human trial in which the effects of inhaled ectoine on neutrophilic lung inflammation were investigated. Besides demonstrating beneficial effects on inflammatory sputum parameters, the study proves the feasibility of the therapeutic approach in an aged study group.