Antiasthmatic Compounds Targeting β2-Adrenergic Receptor from Perilla frutescens Improved Lung Inflammation by Inhibiting the NF-κB Signaling Pathway

Respiratory Protective Effects of Perilla Leave Varieties (Perilla frutescens) Against Fine Particulate Matter (PM2.5)-induced Damage in Human Nasal Cells

Fine particulate matter (PM2.5) is known to exacerbate chronic respiratory disorders, primarily by inducing inflammatory responses and mucus overproduction. Perilla leaves are reported to have significant health benefits, such as antioxidant, antibacterial, and antiallergic properties, attributed to phenolic compounds that vary depending on genetic diversity. In this study, flavonoid-rich extracts (FRE) from 56 perilla leaf varieties and genetic resources were prepared and screened using a mass screening system. The screening focused on evaluating their anti-inflammatory, mucus-reducing, and respiratory protective effects against PM2.5-induced damage in human nasal cells (RPMI2650). Parameters such as cell viability, nitric oxide (NO) levels, and mucus secretion factor (MUC5AC) concentrations were assessed. Among the 56 varieties, Perilla frutescens var. crispa (YCPL706), sourced from Ulleung Island, Korea, exhibited the highest cell viability (112.50%, 100 μg/mL), lowest NO concentration (9.98 μM, 100 μg/mL), and MUC5AC level (78.65 ng/mL, 100 μg/mL). Further evaluation of YCPL706 FRE demonstrated significant respiratory protective effects, including the inhibition of pro-inflammatory cytokines (TNF-α, IL-6, and IL-1β), MUC5AC, and oxidative stress factors (MDA and ROS), compared to the control cultivar Namcheon. YCPL706 also showed strong antibacterial activity against Pseudomonas aeruginosa (minimum inhibitory concentration: 5 mg/mL). These findings suggest that the genetic resource YCPL706 is a promising candidate for combating PM2.5-induced respiratory damage due to its potent anti-inflammatory, antioxidant, and antibacterial properties.

Qingke Pingchuan granules alleviate airway inflammation in COPD exacerbation by inhibiting neutrophil extracellular traps in mice

BACKGROUND

Chronic obstructive pulmonary disease (COPD) imposes a significant global health and socioeconomic burden. Exacerbations of COPD (ECOPD), characterized by heightened airway inflammation and mucus hypersecretion, adversely affect patient health and accelerate disease progression. Qingke Pingchuan (QKPC) granules, a formulation from Traditional Chinese Medicine initially prescribed for acute bronchitis, have shown unexplored potential in ECOPD management, with mechanisms of action yet to be clarified.

PURPOSE

This study investigates the therapeutic effects of QKPC in a mouse model of ECOPD, focusing on underlying molecular mechanisms.

METHODS

COPD was induced in mice through chronic cigarette smoke (CS) exposure, followed by intratracheal administration of Pseudomonas aeruginosa lipopolysaccharide (LPS) to trigger exacerbation, after which mice were treated with QKPC granules. Major compounds in QKPC were identified via UHPLC-QE-MS, and high-throughput RNA sequencing of lung tissue samples identified differentially expressed genes. Transcriptomic data were integrated with network pharmacology analysis to pinpoint potential pathways, bioactive compounds, and target genes through which QKPC might attenuate ECOPD. Molecular docking, protein-small molecule binding assays, and in vitro analyses further validated interactions between key compounds and target genes, shedding light on plausible signaling pathways.

RESULTS

QKPC treatment led to significant reductions in airway leukocyte infiltration and goblet cell metaplasia in CS- and LPS-exposed mice, accompanied by decreased levels of inflammatory cytokines (IL-6, IL-1β, CXCL1, and TNF-α) and mucin MUC5AC in bronchoalveolar lavage fluid. The integrative transcriptomic and network pharmacology analysis identified the neutrophil extracellular trap (NET) formation pathway as a key mechanism underlying QKPC's protective effect against ECOPD. In vitro assays demonstrated that epigallocatechin-3-gallate (EGCG) and quercetin, two important bioactive compounds in QKPC, significantly inhibited NETosis induced by cigarette smoke extract (CSE) plus LPS in human neutrophils. The two compounds were found to interact directly with the reactive oxidative species (ROS)-generating enzyme NOX2 and its regulatory subunit p47phox. Subsequent in vitro studies further confirmed EGCG and quercetin's capacity to reduce ROS production and downregulate NOX2 and p47phox protein levels in neutrophils stimulated with CSE and LPS. Additionally, in vivo studies confirmed QKPC's efficacy in reducing NET formation, oxidative stress, and NOX2/p47phox protein expression in the lung tissue of ECOPD mice.

CONCLUSION

These findings suggest that QKPC granules alleviate airway inflammation in ECOPD, potentially through inhibition of pulmonary NET formation via the NOX2/p47phox-ROS pathway, underscoring their potential therapeutic application for ECOPD management in clinical settings.

Influence of Secondary Metabolites According to Maturation of Perilla (Perilla frutescens) on Respiratory Protective Effect in Fine Particulate Matter (PM2.5)-Induced Human Nasal Cell

Fine particulate matter (PM2.5) exposure worsens chronic respiratory diseases through oxidative stress and inflammation. Perilla frutescens (L.) has potential respiratory protective properties, but the impact of growth stages on its beneficial metabolites is unclear. We aimed to evaluate how different growth stages affect phenolic acids, flavonoids, and polycosanols in perilla seeds and flowers and their efficacy in countering PM2.5-induced damage. Perilla seeds and flowers from five varieties at 10, 20, 30, and 40 days post-flowering were analyzed for metabolite content. Their antioxidant, anti-inflammatory, and respiratory protective effects were tested in RPMI 2650 cells. Our findings indicated that perilla flowers contained higher levels of functional components than seeds and exhibited significant variation with maturation. Phenolic acids of perilla flowers were highest at the early stages of maturation after flowering. However, individual flavones of perilla flowers were the highest at the late maturation stages after flowering. Extracts from perilla flowers harvested 20 days after flowering exhibited significant respiratory protection, effectively inhibiting inflammatory cytokines, mucus secretion, and oxidative stress markers. In conclusion, the flower parts of perilla, particularly those harvested 20 days after flowering, are useful materials for obtaining phenolic compounds, including rosmarinic acid, with high antioxidant and respiratory enhancement effects.

Network pharmacology and experimental evidence: MAPK signaling pathway is involved in the anti-asthma roles of Perilla frutescens leaf

Perilla frutescens (PF) leaf is a traditional Chinese medicine and food with beneficial effects on allergic asthma. We sought to elucidate the active compounds, the targets, and underlying mechanisms of PF leaf in the treatment of allergic asthma by using experimental pharmacology and network pharmacology. An OVA-allergic asthma murine model was constructed to evaluate the effect of PF leaf on allergic asthma. And the network pharmacology and western blotting were performed to evaluate its underlying mechanisms in allergic asthma. PF leaf treatment significantly improved the lung function of OVA model mice and mitigated lung injury by significantly reducing of OVA-specific immunoglobulin E in serum, and interleukin 4, interleukin 5 and tumor necrosis factor alpha in the bronchoalveolar lavage fluid. 50 core targets were screened based on 8 compounds (determined by high performance liquid chromatography) through compound-target- disease network. Furthermore, MAPK signaling pathway was identified as the pathway mediated by PF leaf with the most potential against allergic asthma. And the WB results showed that PF leaf could down-regulate the expression of p-ERK, p-JNK and p-p38, which was highly consistent with the predicted targets and pathway network. In conclusion, this study provides the evidence to support the molecular mechanisms of PF leaf on the treatment of allergic asthma using network pharmacology and in vivo experiments.