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.

Reprogramming of arachidonic acid metabolism using α-terpineol to alleviate asthma: insights from metabolomics.

Asthma is a chronic inflammatory disorder in airways with typical pathologic features of airway inflammation and mucus hypersecretion. α-Terpineol is a monocyclic terpene found in many natural plants and foods. It has been reported to possess a wide range of pharmacological activities including anti-inflammatory and expectorant effects. However, the role of α-terpineol in asthma and its potential protective mechanism have not been well elucidated. This study is designed to investigate the pharmacological effect and mechanism of α-terpineol on asthmatic mice using the metabolomics platform. A murine model of asthma was established using ovalbumin (OVA) sensitization and then challenged for one week. The leukocyte count and inflammatory cytokines in the bronchoalveolar lavage fluid (BALF), lung histopathology, inflammatory  infiltrate and mucus secretion were evaluated. An ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS)-based metabolomics study was performed on lung tissues and serum to explore endogenous small molecule metabolites affected by α-terpineol in asthmatic mice. After α-terpineol treatment, leukocyte count, inflammatory cytokines in the BALF, and peribronchial inflammation infiltration were significantly downregulated. Goblet cell hyperplasia and mucus secretion were attenuated, with the level of Muc5ac in BALF decreased. These results proved the protective effect of α-terpineol against airway inflammation, mucus hypersecretion and Th1/Th2 immune imbalance. To further investigate the underlying mechanisms of α-terpineol in asthma treatment, UPLC-MS/MS-based metabolomics analysis was performed. 26 and 15 identified significant differential metabolites were found in the lung tissues and serum of the control, model and α-terpineol groups, respectively. Based on the above differential metabolites, enrichment analysis showed that arachidonic acid (AA) metabolism was reprogrammed in both mouse lung tissues and serum. 5-Lipoxygenase (5-LOX) and cysteinyl leukotrienes (CysLTs) are the key enzyme and the end product of AA metabolism, respectively. In-depth studies have shown that pretreatment with α-terpineol can alleviate asthma by decreasing the AA level, downregulating the expression of 5-LOX and reducing the accumulation of CysLTs in mouse lung tissues. In summary, this study demonstrates that α-terpineol is a potential agent that can prevent asthma via regulating disordered AA metabolism.

Cineole inhibits the biosynthesis of leukotrienes and prostaglandins to alleviate allergic rhinitis: Insights from metabolomics.

Allergic rhinitis (AR) is a common allergic disease characterized by nasal congestion, rhinorrhoea, and sneezing. Cineole, a monoterpenoid compound widely present in various volatile oils, has a wide range of pharmacological activities and is of interest in allergic airway diseases for its anti-inflammatory and anti-mucus production abilities. However, the protective effects of cineole in mice with allergic rhinitis and its mechanisms have not been well investigated. In this study, the protective effect of cineole against ovalbumin-induced (OVA-induced) allergic rhinitis and its molecular mechanism is investigated by metabolomic analysis based on ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). OVA combined with aluminum hydroxide adjuvant is used to sensitize and establish the allergic rhinitis (AR) mouse model. The mice are randomly divided into groups of control, AR, cineole (30 mg/kg), and budesonide (38.83 µg/kg). The pharmacodynamic results show that cineole significantly reduces the levels of Th2-type cytokines and OVA-specific IgE (OVA-sIgE) in AR mice, improves nasal mucosal tissue damage and alleviates nasal symptoms compared to the untreated AR group. Metabolomic results show that arachidonic acid (AA) metabolism and tryptophan (Trp) metabolism are reprogrammed on the basis of 27 significantly altered metabolites. Further studies show that cineole inhibits the biosynthesis of pro-inflammatory lipid mediators leukotrienes (LTs) and prostaglandins (PGs) in mice by inhibiting the activity of 5-lipoxygenase (5-LOX) and cyclooxygenase-2 (COX-2) in the arachidonic acid metabolic (AA metabolic) pathway. It also inhibits the production of Th2 cytokines and inflammatory cell infiltration, thereby alleviating symptoms such as nasal congestion and nasal leakage. These results reveal the action and molecular mechanism of cineole in alleviating AR and provide a theoretical basis for the clinical application of cineole in treating AR.

Hepatoprotective effect of Artemisia Argyi essential oil on bisphenol A-induced hepatotoxicity via inhibition of ferroptosis in mice.

The environmental pollutant bisphenol A (BPA), used in the manufacture of plastic packaging materials for various diets, is widely distributed in the environment and causes severe hepatotoxicity by inducing oxidative stress. Artemisia argyi essential oil (AAEO), a volatile oil component isolated from Artemisia argyi H.Lév. & Vaniot, has pharmacological effects, especially for hepatoprotective actions. However, the potential effect of AAEO in BPA induced hepatotoxicity has not been characterized. First, we analyzed the chemical composition in AAEO by gas chromatography-mass spectrometry. Herein, we investigated the effect of AAEO on hepatic metabolic changes in mice exposed to BPA. Results showed that compared with the BPA group, AAEO could reduce the level of liver function enzymes in BPA mice serum, and ameliorate hepatic lesions and fibrosis. Additionally, 20 differential metabolites screened by metabolomics were mainly involved in the reprogramming of glutathione metabolism, purine metabolism, and polyunsaturated fatty acid synthesis. Moreover, AAEO could reduce hepatic ferroptosis induced by BPA, as demonstrated by reducing xanthine oxidase activity, up-regulating the activities of glutathione peroxidase 4 (GPX4), superoxide dismutase, and catalase and the expression of SLC7A11 to promote the glutathione synthetic, while inhibiting transferrin receptor 1 (TFR1) expression to reduce the accumulation of Fe2+ in cells. Therefore, our study identified AAEO as a hepatic protectant against BPA-induced hepatotoxicity by reversing the occurrence of ferroptosis.

Design of 400 V Miniature DC Solid State Circuit Breaker with SiC MOSFET.

Silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (MOSFETs) have the advantages of high-frequency switching capability and the capability to withstand high temperatures, which are suitable for switching devices in a direct current (DC) solid state circuit breaker (SSCB). To guarantee fast and reliable action of a 400 V DC SSCB with SiC MOSFET, circuit design and prototype development were carried out. Taking 400V DC microgrid as research background, firstly, the topology of DC SSCB with SiC MOSFET was introduced. Then, the drive circuit of SiC MOSFET, fault detection circuit, energy absorption circuit, and snubber circuit of the SSCB were designed and analyzed. Lastly, a prototype of the DC SSCB with SiC MOSFET was developed, tested, and compared with the SSCB with Silicon (Si) insulated gate bipolar transistor (IGBT). Experimental results show that the designed circuits of SSCB with SiC MOSFET are valid. Also, the developed miniature DC SSCB with the SiC MOSFET exhibits faster reaction to the fault and can reduce short circuit time and fault current in contrast with the SSCB with Si IGBT. Hence, the proposed SSCB can better meet the requirements of DC microgrid protection.