Gypenoside A from Gynostemma pentaphyllum Attenuates Airway Inflammation and Th2 Cell Activities in a Murine Asthma Model

Mediation of the JNC/ILC2 pathway in DBP-exacerbated allergic asthma: A molecular toxicological study on neuroimmune positive feedback mechanism

BACKGROUND

Dibutyl phthalate (DBP), a commonly used plasticizer, has been found to be strongly linked to a consistently high prevalence of allergic diseases, particularly allergic asthma. Previous animal experiments have demonstrated that exposure to DBP can worsen asthma by triggering the production of calcitonin gene-related peptide (CGRP), a neuropeptide in the lung tissue. However, the precise neuroimmune mechanism and pathophysiology of DBP-exacerbated allergic asthma with the assistance of CGRP remain unclear.

OBJECTIVE

The present study was to investigate the potential pathophysiological mechanism in DBP-exacerbated asthma from the perspective of neural-immune interactions.

METHODS AND RESULTS

C57BL/6 mice were orally exposed to different concentrations (0.4, 4, 40 mg/kg) of DBP for 28 days. They were then sensitized with OVA and nebulized with OVA for 7 consecutive excitations. To investigate whether DBP exacerbates allergic asthma in OVA induced mice, we analyzed airway hyperresponsiveness and lung histopathology. To investigate the activation of JNC and TRPV1 neurons and the release of CGRP by JNC cells, we measured the levels of TRPV1 channels, calcium inward flow, and downstream neuropeptide CGRP. Results showed that TRPV1 expression, inward calcium flux, and CGRP levels were significantly elevated in the lung tissues of the 40DBP + OVA group, suggesting the release of CGRP by JNC cells. To counteract the detrimental effects of DBP mediated by CGRP, we employed olcegepant (also known as BIBN-4096), a CGRP receptor specific antagonist. Results revealed that 40DBP + OVA + olcegepant led to notable decreases in TRPV1, calcium inward flow, and CGRP expression in lung tissues compare with 40DBP + OVA, further supporting the efficacy of olcegepant. Additionally, we also conducted ILC2 flow sorting and observed that neuropeptide CGRP-activated ILC2 cells have a crucial role as key effector cells in DBP-induced neuroimmune positive feedback regulation. Finally, we examined the protein expression of CGRP, GATA3 and P-GATA3, and found that significant upregulations of CGRP and P-GATA3 in the 40DBP + OVA group, suggest that GATA3 acted as a key regulator of CGRP-activated ILC2.

CONCLUSION

The aforementioned studies indicate that exposure to DBP can exacerbate allergic asthma, leading to airway inflammation. This exacerbation occurs through the activation of TRPV1 in JNC, resulting in the release of CGRP. The excessive release of CGRP further promotes the release of Th2 cytokines by inducing the activation of ILC2 through GATA phosphorylation. Consequently, this process contributes to the development of airway inflammation and allergic asthma. The increased production of Th2 cytokines also triggers the production of IgE, which interacts with FcεRI on JNC neurons, thereby mediating neuro-immune positive feedback regulation.

Gypenoside XLIX attenuates sepsis-induced splenic injury through inhibiting inflammation and oxidative stress

BACKGROUND

To investigate the effect of Gypenoside XLIX (Gyp-XLIX) on acute splenic injury (ASI) induced by cecal ligation and puncture (CLP) in septic mice, a study was conducted.

METHODS

Sixty healthy mice were randomly divided into six groups: the NC group, the Sham group, the Sham + Gyp-XLIX group, the CLP group, the CLP + Gyp-XLIX group, and the CLP + Dexamethasone (DEX) group. The NC group did not undergo any operation, while the rest of the groups underwent CLP to establish the sepsis model. The Sham group only underwent open-abdominal suture surgery without cecum puncture. After the operation, the groups were immediately administered the drug for a total of 5 days. Various methods such as hematoxylin and eosin (HE) staining, biochemical kits, qRT-PCR, and reactive oxygen species (ROS) were used for analysis.

RESULTS

The results demonstrated that Gyp-XLIX effectively mitigated the splenic histopathological damage, while reducing the malondialdehyde (MDA) lipid peroxidation index and enhancing the antioxidant activities of catalase (CAT), glutathione (GSH) and total antioxidant capacity (T-AOC). The utilization of Dihydroethidium (DHE) fluorescent probe revealed that Gyp-XLIX inhibited the acute splenic accumulation of ROS induced by CLP in septic mice. Further investigations revealed that Gyp-XLIX exhibited a down-regulatory effect on the protein levels of inflammatory mediators iNOS and COX-2, consequently leading to the suppression of pro-inflammatory cytokines such as TNF-α, IL-6, and IL-1β. Additionally, it up-regulated the expression of anti-inflammatory factor IL-10.

CONCLUSION

In conclusion, Gyp-XLIX was significantly effective in attenuating CLP-induced acute splenic inflammation and oxidative stress in septic mice.

Mulberroside F improves airway hyperresponsiveness and inflammation in asthmatic mice

Mulberroside F is isolated from the leaves and roots of Morus alba L. Here, we investigated whether mulberroside F could alleviate airway inflammation and eosinophil infiltration in the lungs of asthmatic mice. We also examined whether mulberroside F attenuated inflammatory responses in human tracheal epithelial BEAS-2B cells. Female BALB/c mice were sensitized and challenged with ovalbumin (OVA), and administered different doses of mulberroside F via intraperitoneal injection. Additionally, tumor necrosis factor (TNF)-α-stimulated BEAS-2B cells were treated with various doses of mulberroside F, followed by detection of the expressions of inflammatory cytokines and chemokines. The results demonstrated that mulberroside F mitigated the levels of proinflammatory cytokines and chemokines, and CCL11, in inflammatory BEAS-2B cells. Mulberroside F also suppressed reactive oxygen species (ROS) production and ICAM-1 expression in TNF-α-stimulated BEAS-2B cells, which effectively suppressed monocyte cell adherence. In an animal model of asthma, mulberroside F treatment attenuated airway hyperresponsiveness, eosinophil infiltration, and goblet cell hyperplasia. Mulberroside F treatment also decreased lung fibrosis and airway inflammation in OVA-sensitized mice. Moreover, mulberroside F significantly reduced expressions of Th2-associated cytokines (including interleukin(IL)-4, IL-5, and IL-13) in bronchoalveolar lavage fluid compared to OVA-sensitized mice. Our results confirmed that mulberroside F is a novel bioactive compound that can effectively reduce airway inflammation and eosinophil infiltration in asthmatic mice via inhibition of Th2-cell activation.

Editorial of Special Issue "Molecular Mechanisms of Natural Products and Phytochemicals in Immune Cells and Asthma"

The Special Issue "Molecular Mechanisms of Natural Products and Phytochemicals in Immune Cells and Asthma" in the International Journal of Molecular Sciences includes original research and reviews on the molecular mechanisms of active, natural products (medicinal plants and animal ones) and phytochemicals in vitro and in vivo [...].