Sensitized Guinea Pigs Research Articles

20S-Ginsenoside Rh2, the major bioactive saponin in Panax notoginseng flowers, ameliorates cough by inhibition of NaV1.7 and TRPV1 channel currents and downregulation of TRPV1 expression

Ethnopharmacological relevancePanax notoginseng flowers, which are the buds of the traditional Chinese medicinal herb Sanqi, are widely used in China for their cough-ameliorating properties, with demonstrated therapeutic effects in the treatment of both acute and chronic coughs. However, both the antitussive mechanism and active compound basis of P. notoginseng flowers remain poorly understood. Aim of the studyWe investigated the antitussive effects of P. notoginseng flowers, identified the bioactive constituents responsible for alleviating cough symptoms, and elucidated the underlying pharmacological mechanisms. Materials and methodsWe analyzed the major chemical constituents of aqueous extracts of P. notoginseng flowers using liquid chromatography–mass spectrometry and quantitatively analyzed the key component, 20S-ginsenoside Rh2, using high-performance liquid chromatography. Using a cough reflex model in healthy mice and an ovalbumin-induced, highly sensitive guinea pig cough model, we verified the suppressive effects of P. notoginseng flowers and their saponin constituents on coughing. Furthermore, we explored the mechanisms of action of the key ion channels, NaV1.7 and TRPV1, using whole-cell patch-clamp techniques and molecular docking. Finally, the therapeutic mechanisms of P. notoginseng flowers on pathological cough were revealed using hematoxylin and eosin staining, immunohistochemistry, and western blotting. ResultsThe active components of P. notoginseng flowers were primarily protopanaxadiol-type saponins, among which 20S-ginsenoside Rh2 had the highest content (51.46 mg/g). In the mouse model, P. notoginseng flowers exhibited antitussive effects comparable to those of pentoxyverine citrate. Although its main saponin component, 20S-ginsenoside Rh2, showed slightly weaker effects, it still demonstrated concentration-dependent inhibition of channel activity. The whole-cell patch-clamp technique and virtual molecular docking showed that Rh2 might exert its effects by directly binding to the NaV1.7 and TRPV1 channels. In the guinea pig model, P. notoginseng flowers and their saponin components not only reduced cough frequency and prolonged the latency period before cough onset, but also significantly inhibited tracheal and pulmonary inflammation and the overexpression of TRPV1. Conclusions20S-Ginsenoside Rh2, the major bioactive saponin in P. notoginseng flowers, exhibits potent antitussive effects. The potential mechanism of action of 20S-Ginsenoside Rh2 in the treatment of cough may involve inhibiting NaV1.7 and TRPV1 channel currents through direct binding to core protein active sites and downregulating TRPV1 expression.

In vitro and in vivo burn healing study of standardized propolis: Unveiling its antibacterial, antioxidant and anti-inflammatory actions in relation to its phytochemical profiling.

Natural propolis has been used since decades owing to its broad-spectrum activities. Burn injuries are a global health problem with negative impacts on communities. Bacterial infections usually accompany burns, which demand implementation of antibiotics. Antibiotics abuse led to emergence of microbial drug resistance resulting in poor treatment outcomes. In such instances, the promising alternative would be natural antimicrobials such as propolis. Full chemical profiling of propolis and evaluation of in vitro antibacterial, antioxidant and anti-inflammatory activities as well as in vivo burn healing properties. Chemical profiling of propolis was performed using Liquid chromatography (UHPLC/MS-PDA and HPLC-PDA). In vitro assessment was done using Disc Diffusion susceptibility test against Staphylococcus aureus and infected burn wound mice model was used for in vivo assessment. In vitro antioxidant properties of propolis were assessed using DPPH, ABTS and FRAP techniques. The anti-inflammatory effect of propolis was assessed against lipopolysaccharide/interferon-gamma mediated inflammation. UHPLC/MS-PDA results revealed identification of 71 phytochemicals, mainly flavonoids. Upon flavonoids quantification (HPLC-PDA), Pinocembrin, chrysin and galangin recorded high content 21.58±0.84, 22.73±0.68 and 14.26±0.70 mg/g hydroalcoholic propolis extract, respectively. Propolis showed concentration dependent antibacterial activity in vitro and in vivo burn healing via wound diameter reduction and histopathological analysis without signs of skin irritation in rabbits nor sensitization in guinea pigs. Propolis showed promising antioxidant IC50 values 46.52±1.25 and 11.74±0.26 μg/mL whereas FRAP result was 445.29±29.9 μM TE/mg. Anti-inflammatory experiment results showed significant increase of Toll-like receptor 4 (TLR4), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) mRNA levels. Nitric oxide and iNOS were markedly increased in Griess assay and western blot respectively. However, upon testing propolis against LPS/IFN-γ-mediated inflammation, TLR4, IL-6 and TNF-α expression were downregulated at transcriptional and post-transcriptional levels. Propolis proved to be a promising natural burn healing agent through its antibacterial, antioxidant and anti-inflammatory activities.

Sex differences in plasma metabolites in a guinea pig model of allergic asthma.

Sex seems to be a contributing factor in the pathogenesis of bronchial asthma. This study aimed to find sex-related differences in metabolome measured by hydrogen-1 nuclear magnetic resonance ((1)H NMR) spectroscopy in healthy and ovalbumin (OVA)-sensitized guinea pigs. Adult male and female animals were divided into controls and OVA-sensitized groups. OVA-sensitization was performed by OVA systemic and inhalational administration within 14 days; on day 15, animals were killed by anesthetic overdose followed by exsanguination. Blood was taken and differential white blood cell count was measured. Left lung was saline-lavaged and differential cell count in the bronchoalveolar lavage fluid (BALF) was measured. After blood centrifugation, plasma was processed for (1)H NMR analysis. Metabolomic data was evaluated by principal component analysis (PCA). Eosinophil counts elevated in the BALF confirming eosinophil-mediated inflammation in OVA-sensitized animals of both sexes. Sex differences for lactate, glucose, and citrate were found in controls, where these parameters were lower in males than in females. In OVA-sensitized males higher glucose and lower pyruvate were found compared to controls. OVA-sensitized females showed lower lactate, glucose, alanine, 3-hydroxy-butyrate, creatine, pyruvate, and succinate concentrations compared to controls. In OVA-sensitized animals, lactate concentration was lower in males. Data from females (healthy and OVA-sensitized) were generally more heterogeneous. Significant sex differences in plasma concentrations of metabolites were found in both healthy and OVA-sensitized animals suggesting that sex may influence the metabolism and may thereby contribute to different clinical picture of asthma in males and females.

New phosphodiesterase-4 inhibitors present airways relaxant activity in a guinea pig acute asthma model.

Asthma is a disease characterized by chronic inflammation and hyper responsiveness of airways. We aimed to assess the relaxant potential of phosphodiesterase-4 (PDE4) inhibitors N-sulfonilhidrazonic derivatives on non-asthmatic and asthmatic guinea pig trachea. Firstly, guinea pigs were sensitized and challenged with ovalbumin, and then morphological, and contractile changes were evaluated resulting from asthma, followed by evaluation of relaxant effect of derivatives on guinea pig trachea and the cAMP levels measurement by ELISA. It has been evidenced hypertrophy of airway smooth muscle, inflammatory infiltrate, and vascular abnormalities. Moreover, only sensitized tracheal rings were responsive to OVA. Contractile response to histamine, but not to carbachol, was greater in sensitized animals, however the relaxant response to aminophylline and isoprenaline were the same in non-asthmatics and asthmatics. N-sulfonilhidrazonic derivatives presented equipotent relaxant action independent of epithelium, with exception of LASSBio-1850 that presented a low efficacy (< 50%) and LASSBio-1847 with a 4-fold higher potency on asthmatics. LASSBio-1847 relaxant curve was impaired in the presence of propranolol and potentiated by isoprenaline in both groups. Furthermore, relaxation was potentiated 54- and 4-fold by forskolin in non-asthmatics and asthmatics, respectively. Likewise, LASSBio-1847 potentiated relaxant curve of aminophylline 147- and 4-fold in both groups. The PKA inhibitor H-89 impaired the relaxant potency of the derivative. Finally, LASSBio-1847 increased tracheal intracellular cAMP levels similarly to rolipram, selective PDE4 inhibitor, in both animals. LASSBio-1847 showed to be promising to relax guinea pig trachea from non-sensitized and sensitized guinea pigs by activation of β2-adrenergic receptors/AC/cAMP pathway.

Gabapentin alleviated the cough hypersensitivity and neurogenic inflammation in a guinea pig model with repeated intra-esophageal acid perfusion

ObjectiveThe anti-tussive effect of gabapentin and its underlying neuromodulatory mechanism were investigated via a modified guinea pig model of gastroesophageal reflux-related cough (GERC). MethodsIntra-esophageal perfusion with hydrochloric acid (HCl) was performed every other day 12 times to establish the GERC model. High-dose gabapentin (48 mg/kg), low-dose gabapentin (8 mg/kg), or saline was orally administered for 2 weeks after modeling. Cough sensitivity, airway inflammation, lung and esophagus histology, levels of substance P (SP), and neurokinin-1 (NK1)-receptors were monitored. ResultsRepeated intra-esophageal acid perfusion aggravated the cough sensitivity in guinea pigs in a time-dependent manner. The number of cough events was significantly increased after 12 times HCl perfusion, and the hypersensitivity period was maintained for 2 weeks. The SP levels in BALF, trachea, lung, distal esophagus, and vagal ganglia were increased in guinea pigs receiving HCl perfusion. The intensity of cough hypersensitivity in the GERC model was significantly correlated with increased SP expression in the airways. Both high and low doses of gabapentin administration could reduce cough hypersensitivity exposed to HCl perfusion, attenuate airway inflammatory damage, and inhibit neurogenic inflammation by reducing SP expression from the airway and vagal ganglia. ConclusionsGabapentin can desensitize the cough sensitivity in the GERC model of guinea pig. The anti-tussive effect is associated with the alleviated peripheral neurogenic inflammation as reflected in the decreased level of SP.

Protective properties of AgNPs green-synthesized by Camellia sinensis on ovalbumin-induced allergic conjunctivitis

Allergic conjunctivitis is the main usual red eye cause influencing many people. Allergic conjunctivitis is like an umbrella that includes different types of clinical manifestations, from a mild but annoying form of IgE-dependent allergy to inhaled allergens to very severe forms such as keratoconjunctivitis. Cornea involvement in allergic conjunctivitis needs the steroids use, which can cause severe eye complications. Research on allergic conjunctivitis should focus more on more severe forms of eye allergies to gain a better the pathophysiology understanding of the disease, diagnosis methods should be standardized and new treatment methods should be suggested. In the recent study, due to high therapeutic effects of Camellia sinensis, we used its aqueous extract for green-synthesizing of the silver nanoparticles and allergic conjunctivitis treatment in the in vivo condition. UV–Vis spectroscopy, FE-SEM and TEM were used for characterization of nanoparticles. This research therefore evaluated the AgNPs@Camellia sinensis antiallergic potential in ovalbumin-induced allergic conjunctivitis and attempted to predict its mode of action. ELISA determined serum ovalbumin-specific total IgE, IgE and IgG. Clinical scores for allergic conjunctivitis induced by intraperitoneal ovalbumin sensitization and topical conjunctival challenge in Dunkin-Hartley guinea pigs were estimated after treatment with 10, 20, 40 and 80 µg kg−1 AgNPs@Camellia sinensis, 10 mg kg−1 chlorpheniramine, 30 mg kg−1 prednisolone, or 10 mL kg−1 PBS. Serum ovalbumin-specific total IgE, IgE and IgG decreased significantly (p < 0.01). The conjunctival tissue in AgNPs@Camellia sinensis treated guinea pigs had mild mononuclear infiltration compared to the PBS-treated ones, which had intense conjunctival tissue inflammatory infiltration. The 40 and 80 mg kg−1 AgNPs@Camellia sinensis treatment resulted in allergic conjunctivitis low clinical score.

Formulation of a drug for the treatment of allergic conjunctivitis: Copper nanoparticles containing Olea europaea leaf aqueous extract

Olea europaea or Olive is the main ingredient of the Mediterranean diet. They are associated with many health benefits, especially for heart health and cancer prevention. Olive is rich in antioxidants and its health benefits range from fighting inflammation to reducing the growth of microorganisms. Recently, metallic nanoparticles green-formulated by ethnomedicinal plants have been used due to the antioxidant and anti-inflammatory potentials. Present research discloses the CuNPs biosynthesizing capability of the leaves of pharmacologically important Olea europaea. In addition, we investigated the Olea europaea green-formulated copper nanoparticles for the treatment of ovalbumin-induced allergic conjunctivitis. For determining the physicochemical properties of the recent nanoparticles, FT-IR, FE-SEM, UV-Vis and TEM were used. ELISA test was applied to measure the serum ovalbumin-specific IgG and IgE and total IgE. Clinical scores for allergic conjunctivitis induced by intraperitoneal ovalbumin sensitization and topical conjunctival challenge in guinea pigs were determined after a week’s daily treatment with 30 mg kg−1 prednisolone, 10 mg kg−1 chlorpheniramine, 2, 4, 8 and 16 µg kg−1 copper nanoparticles, or 10 mL kg−1 PBS. Ovalbumin-specific IgG and IgE as well as total serum IgE also decreased significantly (p<0.01). All doses of copper nanoparticles treatment resulted in a significantly (p<0.01) low clinical score of allergic conjunctivitis. The conjunctival tissue in copper nanoparticles treated guinea pigs had mild mononuclear infiltration compared to the PBS-treated ones, which had intense conjunctival tissue inflammatory infiltration.

Berberine Improves Histopathological Changes of Allergic Airway Inflammation in Guinea Pigs

&lt;p&gt;&lt;strong&gt;Background and Objective:&lt;/strong&gt; Berberine has anti-inflammatory properties through pathways that are also involved in asthma. Therefore, it is postulated that it will be effective in reducing airway inflammation in the allergic asthmatic model. The objective of the current study was to observe the effects of berberine on the histopathology of lungs in sensitized Guinea pigs and compare the changes with that of the standard drug, dexamethasone.&lt;/p&gt;&#x0D; &lt;p&gt;&lt;strong&gt;Methods:&lt;/strong&gt; This experimental study was conducted at the Postgraduate Medical Institute, Lahore, Pakistan, from February 2016 to April 2016. Twenty-four healthy Guinea pigs were divided randomly into four groups: normal control, Ovalbumin (OVA ) group, OVA + berberine group, and OVA + dexa group. The last three groups were sensitized on days 0 and 14 and challenged on days 25, 26, and 27 with OVA. Berberine and dexamethasone were administered intraperitoneally to the respective groups before each challenge. The animals were then sacrificed on day 28 under anesthesia, lungs were dissected, and tissue samples were assessed microscopically for morphology and status of inflammation in each group. Data were analyzed by applying the Kruskal-Wallis analysis of variance test followed by the Mann Whitney U test using SPSS 20.&lt;/p&gt;&#x0D; &lt;p&gt;&lt;strong&gt;Results:&lt;/strong&gt; The comparison of histopathological changes revealed that the infiltration of inflammatory cells in the lung airways was significantly higher (p-value &amp;le;0.01) in the OVA group as compared to the normal control group. Both OVA + berberine and OVA + dexa groups showed a reduction in total lung inflammation (p-value &amp;le;0.01 vs. OVA group) equally. The effect of berberine on epithelial changes was nonsignificant (p-value 0.206 vs. OVA group), while dexamethasone showed significant improvement as compared to the OVA group (p-value 0.007). However, the difference between berberine and dexamethasone treatment was nonsignificant (p-value &amp;le;0.05).&lt;/p&gt;&#x0D; &lt;p&gt;&lt;strong&gt;Conclusion: &lt;/strong&gt;It was concluded that berberine improved the histopathological score of lung inflammation in sensitized Guinea pigs, equivalent to that of dexamethasone, with lesser effects on epithelial changes.&lt;/p&gt;

Green formulation and characterization of Camellia azalea synthesized copper nanoparticles and its application in the treatment of ovalbumin-induced allergic conjunctivitis

Camellia azalea can treat many stubborn and malignant diseases, according to traditional Chinese medicine. In addition, it has been indicated that copper nanoparticles containing the plant have many therapeutic effects. Recently, metallic nanoparticles have been used due to the antioxidant and anti-inflammatory potentials. Present research discloses the CuNPs biosynthesizing capability of the leaves of pharmacologically important Camellia azalea. For determining the physicochemical properties of the recent nanoparticles, FE-SEM, FT-IR, TEM and UV-Vis were used. This study therefore assessed the antiallergic potential of copper nanoparticles in ovalbumin-induced allergic conjunctivitis and attempted to predict its action mode. ELISA test was applied to measure the serum ovalbumin-specific IgG and IgE and total IgE. Clinical scores for allergic conjunctivitis induced by intraperitoneal ovalbumin sensitization and topical conjunctival challenge in Dunkin-Hartley guinea pigs were determined after a week’s daily treatment with 10 mg kg−1 chlorpheniramine, 30 mg kg−1 prednisolone, 15 and 80 µg kg−1 copper nanoparticles, or 10 mL kg−1 PBS. The 15 and 60 mg kg−1 copper nanoparticles treatment resulted in a significantly (p < 0.01) low clinical score of allergic conjunctivitis. Ovalbumin-specific IgG and IgE as well as total serum IgE also decreased significantly (p < 0.01). The conjunctival tissue in copper nanoparticles treated guinea pigs had mild mononuclear infiltration compared to the PBS-treated ones, which had intense conjunctival tissue inflammatory infiltration.

3-[5-(1H-Indol-3-ylmethylene)-4-oxo-2-thioxothiazolidin-3-yl]-propionic Acid as a Potential Polypharmacological Agent

Searching for new types of biological activities among preliminarily identified hit compounds is a key challenge in modern medicinal chemistry. In our study, a previously studied 3-[5-(1H-indol-3-ylmethylene)-4-oxo-2-thioxothiazolidin-3-yl]-propionic acid (Les-6614) was screened for antimicrobial, antifungal, anti-allergic, and antitumor activities. Moreover, cytotoxicity, molecular docking, and SwissAdme online target screening were accomplished. It was determined that the Les-6614 has slight antimicrobial and antitumor activity. However, the studied compound decreased IgE levels in sensitized guinea pigs by 33–86% and reduced IgA, IgM, IL-2, and TNF-α, indicating anti-inflammatory and anti-allergic aactivities. According to the SwissADME web tool, target predictions for Les-6614 potentially have an affinity for lysosomal protective protein, Thromboxane-A synthase, and PPARγ. The molecular docking confirmed that the studied 2-thioxo-4-thiazolidinone derivative showed good bonding with LLP and TXAS, leading to stable protein–ligand complexes. Additionally, Les-6614 is a potential PPARγ modulator, which is important in the pathogenesis of allergy, cancer, and cardiovascular diseases.

Role of 5-HT2 receptors family in the allergy-induced increased aorta contractile responses to 5-HT.

Asthma poses an increased risk for cardiovascular disorders, suggesting that allergy, which is an underlying process in asthma, causes atypical functioning of organs other than lungs. In a previous study in a guinea pig asthma model, we concluded that allergic sensitization increased aorta contractile responses to 5-HT. To further characterize these responses, here we explored the role of the 5-HT2 receptors family. We found that TCB-2 (5-HT2A agonist) and WAY161503 (5-HT2C agonist) induced aorta contractions resembling those elicited by 5-HT but less intense (~43 % and ~25 %, respectively). In these experiments, aortas from sensitized guinea pigs showed increased contractions to TCB-2, but not to WAY161503. In turn, MDL 100907 (5-HT2A antagonist) and RS-102221 (5-HT2C antagonist) caused a notably and a mild reduction of the 5-HT-induced contractions, respectively, with no differences seen between sensitized and non-sensitized tissues. BW723C86 (5-HT2B agonist) did not induce contractile responses and RS-127445 (5-HT2B antagonist) did not modify the contractile responses to 5-HT. In non-sensitized aortas, the pattern of protein expression of receptors was 5HT2B>5-HT2A=5-HT2C, which did not change in sensitized animals. In conclusion, we found that allergic sensitization increased the aorta contractile responses to 5-HT, partly mediated by enhanced responses of 5-HT2A receptors, which was unrelated to changes in the expression of these receptors.

Electroacupuncture Reduces Ocular Surface Neuralgia in Dry-Eyed Guinea Pigs by Inhibiting the Trigeminal Ganglion and Spinal Trigeminal Nucleus Caudalis P2X3R-PKC Signaling Pathway

Purpose To observe the effects of electroacupuncture on ocular surface neuralgia and the P2X3R-PKC signaling pathway in guinea pigs with dry eye. Methods A dry eye guinea pig model was established by subcutaneous injection of scopolamine hydrobromide. Guinea pigs were monitored for body weight, palpebral fissure height, number of blinks, corneal fluorescein staining score, phenol red thread test, and corneal mechanical perception threshold. Histopathological changes and mRNA expression of P2X3R and protein kinase C in the trigeminal ganglion and spinal trigeminal nucleus caudalis were observed. We performed a second part of the experiment, which involved the P2X3R-specific antagonist A317491 and the P2X3R agonist ATP in dry-eyed guinea pigs to further validate the involvement of the P2X3R-protein kinase C signaling pathway in the regulation of ocular surface neuralgia in dry eye. The number of blinks and corneal mechanical perception threshold were monitored before and 5 min after subconjunctival injection and the protein expression of P2X3R and protein kinase C was detected in the trigeminal ganglion and spinal trigeminal nucleus caudalis of guinea pigs. Results Dry-eyed guinea pigs showed pain-related manifestations and the expression of P2X3R and protein kinase C in the trigeminal ganglion and spinal trigeminal nucleus caudalis was upregulated. Electroacupuncture reduced pain-related manifestations and inhibited the expression of P2X3R and protein kinase C in the trigeminal ganglion and spinal trigeminal nucleus caudalis. Subconjunctival injection of A317491 attenuated corneal mechanoreceptive nociceptive sensitization in dry-eyed guinea pigs, while ATP blocked the analgesic effect of electroacupuncture. Conclusions Electroacupuncture reduced ocular surface sensory neuralgia in dry-eyed guinea pigs, and the mechanism of action may be associated with the inhibition of the P2X3R-protein kinase C signaling pathway in the trigeminal ganglion and spinal trigeminal nucleus caudalis by electroacupuncture.

Monensin inhibits mast cell mediated airway contractions in human and guinea pig asthma models

Asthma is a common respiratory disease associated with airway hyperresponsiveness (AHR), airway inflammation and mast cell (MC) accumulation in the lung. Monensin, an ionophoric antibiotic, has been shown to induce apoptosis of human MCs. The aim of this study was to define the effect of monensin on MC responses, e.g., antigen induced bronchoconstriction, and on asthmatic features in models of allergic asthma. Tracheal segments from house dust mite (HDM) extract sensitized guinea pigs were isolated and exposed to monensin, followed by histological staining to quantify MCs. Both guinea pig tracheal and human bronchi were used for pharmacological studies in tissue bath systems to investigate the monensin effect on tissue viability and antigen induced bronchoconstriction. Further, an HDM-induced guinea pig asthma model was utilized to investigate the effect of monensin on AHR and airway inflammation. Monensin decreased MC number, caused MC death, and blocked the HDM or anti-IgE induced bronchoconstriction in guinea pig and human airways. In the guinea pig asthma model, HDM-induced AHR, airway inflammation and MC hyperplasia could be inhibited by repeated administration of monensin. This study indicates that monensin is an effective tool to reduce MC number and MCs are crucial for the development of asthma-like features.

Evaluation of a Human T Cell-Targeted Multi-Epitope Vaccine for Q Fever in Animal Models of Coxiella burnetii Immunity

T cell-mediated immunity plays a central role in the control and clearance of intracellular Coxiella burnetii infection, which can cause Q fever. Therefore, we aimed to develop a novel T cell-targeted vaccine that induces pathogen-specific cell-mediated immunity to protect against Q fever in humans while avoiding the reactogenicity of the current inactivated whole cell vaccine. Human HLA class II T cell epitopes from C. burnetii were previously identified and selected by immunoinformatic predictions of HLA binding, conservation in multiple C. burnetii isolates, and low potential for cross-reactivity with the human proteome or microbiome. Epitopes were selected for vaccine inclusion based on long-lived human T cell recall responses to corresponding peptides in individuals that had been naturally exposed to the bacterium during a 2007-2010 Q fever outbreak in the Netherlands. Multiple viral vector-based candidate vaccines were generated that express concatemers of selected epitope sequences arranged to minimize potential junctional neo-epitopes. The vaccine candidates caused no antigen-specific reactogenicity in a sensitized guinea pig model. A subset of the vaccine epitope peptides elicited antigenic recall responses in splenocytes from C57BL/6 mice previously infected with C. burnetii. However, immunogenicity of the vaccine candidates in C57BL/6 mice was dominated by a single epitope and this was insufficient to confer protection against an infection challenge, highlighting the limitations of assessing human-targeted vaccine candidates in murine models. The viral vector-based vaccine candidates induced antigen-specific T cell responses to a broader array of epitopes in cynomolgus macaques, establishing a foundation for future vaccine efficacy studies in this large animal model of C. burnetii infection.

The resistive region of pulmonary microvessels in ovalbumin-sensitised guinea pigs: a quantitative and qualitative histological study

This work aimed to study the morphofunctional changes in the resistive region of the pulmonary microcirculatory bed in ovalbumin- sensitised guinea pigs. Using histological, morphometric, and statistical methods, we studied the lungs of 48 male guinea pigs in conditions of the experimental allergic inflammatory process. To assess the structural and functional state of medium (51– 125 μm) and small (25–50 μm) arterioles, the outer and inner diameters, the thickness of the tunica media, and the Kernogan index were determined. The most pronounced changes, such as thickening of their walls and narrowing of the lumen in the late stages of the allergic inflammatory process, consisted in the restructuring of medium arterioles. Compared to control animals, the inner diameter of the medium arterioles decreased three times (p*/**&lt;0.05) in experimental group 4; the thickness of the tunica media of medium arterioles increased two times (p*/**&lt;0.05) in experimental group 3. These changes are the result of the increasing tone and hypertrophy of the smooth muscles of the tunica media and the decreasing capacity of arterioles as evidenced by a statistically significant increase of the Kernogan index-indicated hypertrophy and the increasing tone of the smooth muscles of the tunica media and decreasing vascular throughput.

Dermatitis in Greenhouse Farmers Caused by Acaricide Cyflumetofen - An Interview Study

Pesticides are essentially toxic to living things, and, as they are used openly, it is necessary to monitor them and to prevent their adverse effects. A self-administered questionnaire survey given to a group of the greenhouse farmers told us that some of them developed dermatitis from acaricide cyflumetofen, so we conducted an interview study on dermatitis caused by cyflumetofen. The participants were affiliated with a strawberry producing group, and were interviewed at their annual health checkups in the spring of 2016 and 2017. The questions covered the status of spraying, dermatitis from cyflumetofen, and visitations to clinics/hospitals. Of 108 farmers interviewed, 20 had subjective symptoms of dermatitis from cyflumetofen. Seven of them had visited clinics/hospitals. The most affected body part was the face, especially around the eyes, followed by the hands and forearms. The subjective symptoms varied from slight (rubor and itching) to serious (swelling with aching around the eyes). Three male farmers had visited clinics/hospitals for 3-4 weeks, and had stopped using cyflumetofen. We advised them to continue avoiding the use of cyflumetofen, considering the results of an animal test: a "pesticide abstract" stated that cyflumetofen had caused skin sensitization in guinea pigs. It is necessary, therefore, to mention this skin sensitization in the safety datasheet of cyflumetofen.

Role of airway smooth muscle cell phenotypes in airway tone and obstruction in guinea pig asthma model

BackgroundAirway obstruction (AO) in asthma is driven by airway smooth muscle (ASM) contraction. AO can be induced extrinsically by direct stimulation of ASM with contractile agonists as histamine, or by indirect provocation with antigens as ovalbumin, while the airway tone is dependent on intrinsic mechanisms. The association of the ASM phenotypes involved in different types of AO and airway tone in guinea pigs was evaluated.MethodsGuinea pigs were sensitized to ovalbumin and challenged with antigen. In each challenge, the maximum OA response to ovalbumin was determined, and before the challenges, the tone of the airways. At third challenge, airway responsiveness (AR) to histamine was evaluated and ASM cells from trachea were disaggregated to determinate: (a) by flow cytometry, the percentage of cells that express transforming growth factor-β1 (TGF-β1), interleukin-13 (IL-13) and sarco-endoplasmic Ca2+ ATPase-2b (SERCA2b), (b) by RT-PCR, the SERCA2B gene expression, (c) by ELISA, reduced glutathione (GSH) and, (d) Ca2+ sarcoplasmic reticulum refilling rate by microfluorometry. Control guinea pig group received saline instead ovalbumin.ResultsAntigenic challenges in sensitized guinea pigs induced indirect AO, AR to histamine and increment in airway tone at third challenge. No relationship was observed between AO induced by antigen and AR to histamine with changes in airway tone. The extent of antigen-induced AO was associated with both, TGF-β1 expression in ASM and AR degree. The magnitude of AR and antigen-induced AO showed an inverse correlation with GSH levels in ASM. The airway tone showed an inverse association with SERCA2b expression.ConclusionsOur data suggest that each type of AO and airway tone depends on different ASM phenotypes: direct and indirect AO seems to be sensitive to the level of oxidative stress; indirect obstruction induced by antigen appears to be influenced by the expression of TGF-β1 and the SERCA2b expression level plays a role in the airway tone.

Pulmonary IFN-γ Causes Lymphocytic Inflammation and Cough Hypersensitivity by Increasing the Number of IFN-γ-Secreting T Lymphocytes.

Respiratory viral infection increases the number of lung-resident T lymphocytes, which enhance cough sensitivity by producing interferon-γ (IFN-γ). It is poorly understood why IFN-γ-secreting T lymphocytes persist for a long time when the respiratory viruses have been removed. Repeated pulmonary administration of IFN-γ and intraperitoneal injection with different inhibitors were used to study the effects of pulmonary IFN-γ in mice and guinea pigs. IFN-γ administration caused the increasing of IFN-γ-secreting T lymphocytes in both lung and blood, followed by the elevated physiological level of IFN-γ in the lung, the airway inflammation and the airway epithelial damage. IFN-γ administration also enhanced the cough sensitivity of guinea pigs. IFN-γ activated the STAT1 and extracellular signal-regulated kinase (ERK) pathways in lung tissues, released IFN-γ-inducible protein 10 (IP-10), and resulted in F-actin accumulation in lung-resident lymphocytes. The CXC chemokine receptor 3 (CXCR3) inhibitor potently suppressed all the IFN-γ-induced inflammatory changes. The STAT1 inhibitor mitigated IFN-γ-secreting T lymphocytes infiltration by inhibiting T lymphocytes proliferation. F-actin accumulation and the ERK1/2 pathway contributed to pulmonary IFN-γ-induced augmentation of the airway inflammation and increasing of IFN-γ-secreting T lymphocytes in blood. High physiological levels of IFN-γ in the lung may cause pulmonary lymphocytic inflammation and cough hypersensitivity by increasing the number of IFN-γ-secreting T lymphocytes through the IP-10 and CXCR3 pathways.

Study of Local Irritant Action of a Prototype Drug Based on Esters of Fatty Acids

In this article, we have presented studies of the local irritating effect of a prototype wound-healing preparation based on water-based fatty acid esters with allantoin. The study of local irritant action included use of extreme dilutions of the drug for intradermal and local use in the induction and provocative phases. The assessment was carried out in points, in the experimental group it was on average 1 point, in control animals on average it was also equal to 1. These studies indicate that the composition has a mild skin reaction of sensitized guinea pigs and does not cause an allergic reaction.

PM2.5 induces airway hyperresponsiveness and inflammation via the AhR pathway in a sensitized Guinea pig asthma-like model

Exposure to fine particulate matter (PM2.5) induces airway inflammation and hyperreactivity that lead to asthma. The mechanisms involved are still under investigation. We investigated the effect of resveratrol (3,4’,5-trihydroxystilbene) (RES) on airway hyperresponsiveness, inflammation and CYP1A1 protein expression (an aryl hydrocarbon receptor (AhR) target) induced by PM2.5 exposure in an allergic asthma experimental guinea pig model. The polyphenolic compound RES was used due to its antioxidant and anti-inflammatory properties and as an antagonist of the AhR; thus, providing mechanistic insights.Animals were sensitized with aluminum hydroxide and ovalbumin and exposed to filtered air or PM2.5. Exposure to PM2.5 was conducted using a whole-body chamber particle concentrator (5 h/day) for 15 days. Animals received saline solution or RES (10 mg/kg per day) orally for 21 days simultaneously to the OVA challenge or PM2.5 exposure.PM2.5 exposure (mean 433 ± 111 μg/m3 in the exposure chamber) in OVA challenged animals induced an asthma-like phenotype characterized by increased baseline lung resistance (Rrs) and central airway resistance (Rn) in response to acetylcholine (ACh) evaluated using a flexiVent system®. A parallel increase of pro-inflammatory cytokines (IL-6, IL-17, TNF-α and IFN-γ), inflammatory cells (eosinophils and neutrophils) in bronchoalveolar lavage fluid (BALF) and lung CYP1A1 increase also occurred. RES significantly inhibited airway hyperresponsiveness, inflammation, and CYP1A1 protein expression in the OVA-challenged PM2.5 exposed animals.In summary, with the use of RES we demonstrate that PM-induced airway hyperreactivity is modulated by the inflammatory response via the AhR pathway in an allergic asthma guinea pig model.