Efficacy and mechanism of essential oil from Abies holophylla leaf on airway inflammation in asthma: Network pharmacology and in vivo study

Artemisia argyi essential oil alleviates asthma by regulating 5-LOX-CysLTs and IDO-1-KYN pathways: Insights from metabolomics

ETHNOPHARMACOLOGICAL RELEVANCE

Artemisia argyi essential oil (AAEO) is a traditional herbal remedy for asthma. However, the potential effect of AAEO on asthma has not been elucidated.

AIM OF THE STUDY

To investigate the protective properties of AAEO upon asthma and elucidate its mechanism.

MATERIALS AND METHODS

The effects of AAEO in asthma were assessed by histology and biochemical analysis. Then, we integrated real-time reverse transcription-quantitative polymerase chain reaction, enzyme-linked immunosorbent assay, immunohistochemistry and metabolomics analysis to reveal its mechanism.

RESULTS

In vivo, AAEO reduced the counts of white blood cells (WBCs) and cytokines in bronchoalveolar lavage fluid (BALF), ameliorated pathologic alterations in lung tissues, and inhibited secretion of OVA-sIgE and muc5ac. Metabolomics results showed that AAEO can exert therapeutic effects on asthmatic mice by regulating disordered arachidonic acid metabolism and tryptophan metabolism. Further studies shown that AAEO inhibited the expression of 5-LOX and reduced the accumulation of CysLTs in mice. Meanwhile, AAEO promoted the activity of IDO-1, facilitated the conversion of tryptophan to kynurenine, and regulated the imbalance of Treg/Th17 immunity. Immunohistochemical results showed that AAEO promoted the expression of IDO-1. RT-qPCR results showed that AAEO promoted the expression of IL-10 and Foxp3 mRNA, and inhibited the expression of IL-17A and RORγt mRNA, thus regulated the imbalance of Treg/Th17 immunity and exerted its therapeutic effects.

CONCLUSION

AAEO treatment not only attenuates the clinical symptoms of asthma but is also involved in regulating lung tissue metabolism. The anti-asthmatic activity of AAEO may be achieved by reprogramming 5-LOX-CysLTs and IDO-1-KYN pathways.

Combination of HPLC–orbitrap‐MS/MS and network pharmacology to identify the anti‐inflammatory phytochemicals in the coffee leaf extracts

In this study, we investigated the phytochemical compositions and the associated anti‐inflammatory activity of coffee leaf fractions prepared by sequential solvent extraction using high‐performance liquid chromatography–orbitrap‐tandem mass spectrometry (HPLC–orbitrap‐MS/MS) combined with network pharmacology. The results showed that the ethyl acetate fraction (EAC‐L) had the highest nitric oxide (NO), ABTS, and DPPH free radical scavenging abilities due to the higher concentrations of mangiferin, rutin, 3,5‐dicaffeoylquinic acid (3,5‐diCQA), and 4,5‐diCQA. The extraction solvents had the greatest impact on the anti‐inflammatory activity of coffee leaf fractions, whereas the processing method had the most significant effect on the antioxidant activity of these fractions. Untargeted metabolomics analysis using HPLC–orbitrap‐MS/MS indicated that palmitic acid, 3,4‐dihydroxybenzaldehyde, and caffeic acid may be involved in the anti‐inflammatory activity of EAC‐L fraction obtained from fresh coffee leaves. On the other hand, processed coffee leaf fraction exhibited anti‐inflammatory activity that was attributed to the presence of 9S,13R‐12‐oxophytodienoic acid, pinocembrin, and quercetin, which have high degree values associated with the inflammation network. Gene ontology and Kyoto encyclopedia of genes and genomes enrichment of network pharmacology analysis showed that these 35 differential compounds in the coffee leaf fractions affect cell transcription, apoptosis, phosphorylation, NO synthesis, phosphatidylinositide 3‐kinases‐protein kinase B (PI3K‐Akt) signaling pathway, focal adhesion, hypoxia‐inducible factor‐1, hepatitis, cancer, and so on. This result indicated that coffee leaf extract may also function as an inhibitor for inflammation‐related cancers. The findings of our research are valuable in guiding the extraction of anti‐inflammatory components from coffee leaves.

Role of Olive Bioactive Compounds in Respiratory Diseases

Respiratory diseases recently became the leading cause of death worldwide, due to the emergence of COVID-19. The pathogenesis of respiratory diseases is centred around inflammation and oxidative stress. Plant-based alongside synthetic drugs were considered as therapeutics due to their proven nutraceutical value. One such example is the olive, which is a traditional symbol of the MedDiet. Olive bioactive compounds are enriched with antioxidant, anti-inflammatory, anticancer and antiviral properties. However, there are few studies relating to the beneficial effect of olive bioactive compounds on respiratory diseases. A vague understanding of its molecular action, dosage and bioavailability limits its usefulness for clinical trials about respiratory infections. Hence, our review aims to explore olive bioactive compound's antioxidant, anti-inflammatory and antiviral properties in respiratory disease defence and treatment. Molecular insight into olive compounds' potential for respiratory system protection against inflammation and ensuing infection is also presented. Olive bioactive compounds mainly protect the respiratory system by subsiding proinflammatory cytokines and oxidative stress.

Protection of taraxasterol against acetaminophen-induced liver injury elucidated through network pharmacology and in vitro and in vivo experiments

BACKGROUND

Drug-induced liver injury (DILI) is primarily caused by drugs or their metabolites. Acetaminophen (APAP) is an over-the-counter antipyretic analgesic that exhibits high hepatotoxicity when used for long-term or in overdoses. Taraxasterol is a five-ring triterpenoid compound extracted from traditional Chinese medicinal herb Taraxacum officinale. Our previous studies have demonstrated that taraxasterol exerts protective effects on alcoholic and immune liver injuries. However, the effect of taraxasterol on DILI remains unclear.

HYPOTHESIS/PURPOSE

This study aimed to elucidate the effects and mechanisms of action of taraxasterol on APAP-induced liver injury using network pharmacology and in vitro and in vivo experiments.

METHODS

Online databases of drug and disease targets were used to screen the targets of taraxasterol and DILI, and a protein-protein interaction network (PPI) was constructed. Core target genes were identified using the tool of Analyze of Cytoscape, gene ontology (GO) and Kyoto Encyclopaedia of Genes and Genomes (KEGG) enrichment analyses were performed. Oxidation, inflammation and apoptosis were evaluated to determine the effect of taraxasterol on APAP-stimulated liver damage in AML12 cells and mice. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blotting were used to explore the potential mechanisms of taraxasterol against DILI.

RESULTS

Twenty-four intersection targets for taraxasterol and DILI were identified. Among them, 9 core targets were identified. GO and KEGG analysis showed that core targets are closely related to oxidative stress, apoptosis, and inflammatory response. The in vitro findings showed that taraxasterol alleviated mitochondrial damage in AML12 cells treated with APAP. The in vivo results revealed that taraxasterol alleviated pathological changes in the livers of mice treated with APAP and inhibited the activity of serum transaminases. Taraxasterol increased the activity of antioxidants, inhibited the production of peroxides, and reduced inflammatory response and apoptosis in vitro and in vivo. Taraxasterol promoted Nrf2 and HO-1 expression, suppressed JNK phosphorylation, and decreased the Bax/Bcl-2 ratio and caspase-3 expression in AML12 cells and mice.

CONCLUSION

By integrating network pharmacology with in vitro and in vivo experiments, this study indicated that taraxasterol inhibits APAP-stimulated oxidative stress, inflammatory response and apoptosis in AML12 cells and mice by regulating the Nrf2/HO-1 pathway, JNK phosphorylation, and apoptosis-related protein expression. This study provides a new evidence for the use of taraxasterol as a hepatoprotective drug.

Abies holophylla Leaf Essential Oil Alleviates Allergic Rhinitis Based on Network Pharmacology

Abies holophylla is an evergreen coniferous species that has been widely used for treating pulmonary diseases and colds. Previous research has demonstrated the anti-inflammatory effect of Abies species and the anti-asthmatic activities of Abies holophylla leaf essential oil (AEO). As asthma and allergic rhinitis (AR) share pathophysiology and pharmacotherapeutic interventions, AEO inhalation can also ameliorate upper respiratory allergic diseases. This study explored the protective effects of AEO on AR with network pharmacological pathway prediction. The potential target pathways of AEO were analyzed by a network pharmacological approach. The BALB/c mice were sensitized by ovalbumin (OVA) and 10 μm particular matter (PM₁₀) to induce allergic rhinitis. Aerosolized AEO 0.0003% and 0.03% were delivered by nebulizer for 5 min a day, 3 times a week for 7 weeks. Nasal symptoms (sneezing and rubbing), histopathological changes in nasal tissues, serum IgE, and zonula occludens-1 (ZO-1) expressions on nasal tissues were analyzed. After AR induction with OVA+PM₁₀ and inhalation of AEO 0.0003% and 0.03% treatment, AEO significantly decreased allergic symptoms (sneezing and rubbing), hyperplasia of nasal epithelial thickness, goblet cell counts, and serum IgE level. The network analysis demonstrated that the possible molecular mechanism of AEO is highly associated with the IL-17 signaling pathway and tight junction. The target pathway of AEO was investigated in RPMI 2650 nasal epithelial cells. Treatment of AEO on PM₁₀-treated nasal epithelial cells significantly reduced the production of inflammatory mediators related to the IL-17 signaling pathway, NF-κB, and the MAPK signaling pathway and prevented the reduction in TJ-related factors. When taken together, AEO inhalation may be considered as a potential treatment for AR by alleviating nasal inflammation and recovering the tight junction.

NJK14047 Suppression of the p38 MAPK Ameliorates OVA-Induced Allergic Asthma during Sensitization and Challenge Periods

p38 MAPK has been implicated in the pathogenesis of asthma as well as pro-allergic Th2 cytokines, orosomucoid-like protein isoform 3 (ORMDL3), regulation of sphingolipid biosynthesis, and regulatory T cell-derived IL-35. To elucidate the role of p38 MAPK in the pathogenesis of asthma, we examined the effect of NJK14047, an inhibitor of p38 MAPK, against ovalbumin (OVA)-induced allergic asthma; we administrated NJK14047 before OVA sensitization or challenge in BALB/c mice. As ORMDL3 regulation of sphingolipid biosynthesis has been implicated in childhood asthma, ORMDL3 expression and sphingolipids contents were also analyzed. NJK14047 inhibited antigen-induced degranulation of RBL-2H3 mast cells. NJK14047 administration both before OVA sensitization and challenge strongly inhibited the increase in eosinophil and lymphocyte counts in the bronchoalveolar lavage fluid. In addition, NJK14047 administration inhibited the increase in the levels of Th2 cytokines. Moreover, NJK14047 reduced the inflammatory score and the number of periodic acid-Schiff-stained cells in the lungs. Further, OVA-induced increase in the levels of C16:0 and C24:1 ceramides was not altered by NJK14047. These results suggest that p38 MAPK plays crucial roles in activation of dendritic and mast cells during sensitization and challenge periods, but not in ORMDL3 and sphingolipid biosynthesis.

Molecular mechanism of the anti-inflammatory effects of plant essential oils: A systematic review

ETHNOPHARMACOLOGICAL RELEVANCE

Plant essential oils (PEOs) extracted from aromatic compounds of the plant contain complex mixtures of volatile and lipophilic bioactive compounds. In ancient Egypt, Arabia, Greece, and China, PEOs were traditional used in aromatherapy for various health disorders, including pain and inflammation.

AIM OF THE STUDY

In this review, we provide an overview of the anti-inflammatory effects of PEOs and the underlying mechanisms associated with anti-inflammatory effects using in vitro and in vivo models. Further, clinical trials associated with PEOs were explored.

MATERIALS AND METHODS

The literature search was performed using various web-based tools and databases like Google Scholar, Web of Science, PubMed, CNKI and SCOPUS. The keywords used for conducting the literature review were general terms like "essential oils" followed by (AND) the subject of interest like "in vitro and/or in vivo anti-inflammatory models," "inflammatory response," "inflammatory indicators," "pro-inflammatory cytokines," "signaling pathway," "anti-inflammatory mechanism," "toxicology and side effects" and "clinical trials." The articles selected were published between 2017 and 2022. The articles prior to 2017 were only considered if they were associated with molecular mechanisms or signaling pathways involved in the inflammatory responses.

RESULTS

In vitro and in vivo inflammation models have been used to study the anti-inflammatory effects of 48 PEOs. Studies have reported that PEOs targets and inhibit multiple dysregulated signaling pathways associated with inflammation, including Toll-like receptors, nuclear transcription factor-κ B, mitogen-activated protein kinases, Nod-like receptor family pyrin domain containing 3, and auxiliary pathways like the nuclear factor erythroid 2-related factor 2/antioxidant response element and Janus kinase/signal transducers and activators of transcription) signaling pathways.

CONCLUSION

PEOs extracted from different plant materials had varied qualitative and quantitative compositions of biologically active compounds. Different anti-inflammatory potentials and different molecular signal transduction have been attributed to PEOs-derived bioactive compounds with different chemical structures. The data on therapeutic efficacy and the long-term side effects of PEOs as an anti-inflammatory drug are still unknown due to the lack of clinical trials on PEOs. There is still insufficient evidence to draw conclusions on anti-inflammatory properties of PEOs without promising outcomes from clinical trials.