Menthone Inhalation Alleviates Local and Systemic Allergic Inflammation in Ovalbumin-Sensitized and Challenged Asthmatic Mice

Impact of Methyl Jasmonate on Terpenoid Biosynthesis and Functional Analysis of Sesquiterpene Synthesis Genes in Schizonepeta tenuifolia

This study investigates the impact of methyl jasmonate (MeJA) on the volatile oil composition of Schizonepeta tenuifolia and elucidates the function of the StTPS45 gene, a key player in terpenoid biosynthesis. The effect of different concentrations of MeJA (0, 50, 100, 200, and 300 μmol/L) on the growth of S. tenuifolia adventitious bud clusters was analyzed over a 20 d period. Using gas chromatography-mass spectrometry (GC-MS), 17 compounds were identified from the adventitious bud clusters of S. tenuifolia. Significant changes in the levels of major monoterpenes, including increased contents of (+)-limonene and (+)-menthone, were observed, particularly at higher concentrations of MeJA. Analysis of transcriptome data from three groups treated with 0, 100, and 300 μmol/L MeJA revealed significant changes in the gene expression profiles following MeJA treatment. At 100 μmol/L MeJA, most terpene synthase (TPS) genes were overexpressed. Additionally, gene expression and functional predictions suggested that StTPS45 acts as germacrene D synthase. Therefore, StTPS45 was cloned and expressed in Escherichia coli, and enzyme activity assays confirmed its function as a germacrene D synthase. Molecular docking and structural prediction of StTPS45 further suggested specific interactions with farnesyl diphosphate (FPP), aligning with its role in the terpenoid synthesis pathway. These findings provide valuable insights into the modulation of secondary metabolite pathways by jasmonate signaling and underscore the potential of genetic engineering approaches to enhance the production of specific terpenoids in medicinal plants.

Phytochemicals as treatment for allergic asthma: Therapeutic effects and mechanisms of action

BACKGROUND

Allergic asthma is an inflammatory disease caused by the immune system's reaction to allergens, inflammation and narrowing of the airways, and the production of more than normal mucus. One of the main reasons is an increased production of inflammatory cytokines in the lungs that leads to the appearance of symptoms of asthma, including inflammation and shortness of breath. On the other hand, it has been proven that phytochemicals with their antioxidant and anti-inflammatory properties can be useful in improving allergic asthma.

PURPOSE

Common chemical treatments for allergic asthma include corticosteroids, which have many side effects and temporarily relieve symptoms but are not a cure. Therefore, taking the help of natural compounds to improve the quality of life of asthmatic patients can be a valuable issue that has been evaluated in the present review.

STUDY DESIGN AND METHODS

In this study, three databases (Scopus, PubMed, and Cochrane) with the keywords: allergic asthma, phytochemical, plant, and herb were evaluated. The primary result was 5307 articles. Non-English, repetitive, and review articles were deleted from the study.

RESULTS AND DISCUSSION

Finally, after carefully reading the articles, 102 were included in the study (2006-2022). The results of this review state that phytochemicals suppress the inflammatory pathways via inhibition of inflammatory cytokines production/secretion, genes, and proteins involved in the inflammation process, reducing oxidative stress indicators and symptoms of allergic asthma, such as cough and mucus production in the lungs.

CONCLUSION

With their antioxidant effects, this study concluded that phytochemicals suppress cytokines and other inflammatory indicators and thus can be considered an adjunctive treatment for improving allergic asthma.

Proposed mechanisms of action of herbal drugs and their biologically active constituents in the treatment of coughs: an overview

Various medicinal plants find their use in cough treatment, based on traditions and long-term experience. Pharmacological principles of their action, however, are much less known. Herbal drugs usually contain a mixture of potentially active compounds, which can manifest diverse effects. Expectorant or antitussive effects, which can be accompanied by others, such as anti-inflammatory or antibacterial, are probably the most important in the treatment of coughs. The aim of this review is to summarize the current state of knowledge of the effects of medicinal plants or their constituents on cough, based on reliable pharmacological studies. First, a comprehensive description of each effect is provided in order to explain the possible mechanism of action in detail. Next, the results related to individual plants and substances are summarized and critically discussed based on pharmacological in vivo and in vitro investigation.

Menthone supplementation protects from allergic inflammation in the lungs of asthmatic mice

To screen potent terpenoid compounds against allergic inflammation in vitro and in vivo, five terpenoid compounds including menthone, farnesol, oridonin, β-escin and lupeol, were first selected to compare their anti-allergic inflammation potential using mouse lung mast cells in vitro. Among five selected terpenoid compounds, just menthone treatment decreased TNF-α/IL-10 secretion ratios in lipopolysaccharide -stimulated mast cells in vitro. As a result, menthone was further chosen to treat ovalbumin (OVA)-sensitized and challenged BALB/c mice by gavage for 5 weeks. There were six groups including dietary control (DC group, 0 mg menthone/kg b.w./day), 8 (ML group), 40 (MM group) as well as 200 mg menthone/kg b.w./day (MH group) by gavage, positive control (PC group, 3 mg dexamethasone/kg b.w. by gavage before OVA challenge) and non-treatment control (NTC group, normal mice without treatment) in the experiment. Changes of inflammatory mediators, cell distribution, Th1/Th2 and pro-/anti-inflammatory cytokines secretion as well as relative gene expression amounts of six receptors related to allergic inflammation in the lungs and airways were measured. The results showed that middle menthone supplementation (40 mg menthone/kg b.w./day) in vivo decreased protein and eotaxin, but increased Th1 cytokine levels in the bronchoalveolar lavage fluid. Menthone supplementation inhibited eosinophilia, mast cell degranulation, chemokine (C-C motif) receptor 3 (CC receptor 3) and chemokine (C-X-C motif) receptor 1 (CXC receptor 1) gene expression amounts in the lungs, but restored the percentage of monocytes/macrophages. Our results suggest that menthone supplementation may alleviate allergic asthma through regulating airway allergic inflammation, protein overproduction, eosinophils infiltration, Th1/Th2 immune balance, CC receptor 3 and CXC receptor 1 gene expression amounts in the lungs but restoring the percentage of monocytes/macrophages in allergic asthmatic mice.