Preventive and Therapeutic Effects of Thymol in a Lipopolysaccharide-Induced Acute Lung Injury Mice Model

Modulation of innate immunity related genes resulting in prophylactic antimicrobial and antiviral properties

BACKGROUND

The innate immunity acts during the early phases of infection and its failure in response to a multilayer network of co-infections is cause of immune system dysregulation. Epidemiological SARS-CoV-2 infections data, show that Influenza Virus (FLU-A-B-C) and Respiratory Syncytial Virus (RSV) are co-habiting those respiratory traits. These viruses, especially in children (mostly affected by 'multi-system inflammatory syndrome in children' [MIS-C] and the winter pandemic FLU), in the aged population, and in 'fragile' patients are causing alteration in immune response. Then, bacterial and fungal pathogens are also co-habiting the upper respiratory traits (e.g., Staphylococcus aureus and Candida albicans), thus contributing to morbidity in those COVID-19 affected patients.

METHODS

Liquid chromatography coupled with high-resolution mass spectrometry using the quadrupole orbital ion trap analyser (i.e., UHPLC-Q-Orbitrap HRMS) was adopted to measure the polyphenols content of a new nutraceutical formula (Solution-3). Viral infections with SARS-CoV-2 (EG.5), FLU-A and RSV-A viruses (as performed in BLS3 authorised laboratory) and real time RT-PCR (qPCR) assay were used to test the antiviral action of the nutraceutical formula. Dilution susceptibility tests have been used to estimate the minimum inhibitory and bactericidal concentration (MIC and MBC, respectively) of Solution-3 on a variety of microorganisms belonging to Gram positive/ negative bacteria and fungi. Transcriptomic data analyses and functional genomics (i.e., RNAseq and data mining), coupled to qPCR and ELISA assays have been used to investigate the mechanisms of action of the nutraceutical formula on those processes involved in innate immune response.

RESULTS

Here, we have tested the combination of natural products containing higher amounts of polyphenols (i.e., propolis, Verbascum thapsus L., and Thymus vulgaris L.), together with the inorganic long chain polyphosphates 'polyPs' with antiviral, antibacterial, and antifungal behaviours, against SARS-CoV-2, FLU-A, RSV-A, Gram positive/ negative bacteria and fungi (i.e., Candida albicans). These components synergistically exert an immunomodulatory action by enhancing those processes involved in innate immune response (e.g., cytokines: IFNγ, TNFα, IL-10, IL-6/12; chemokines: CXCL1; antimicrobial peptides: HBD-2, LL-37; complement system: C3).

CONCLUSION

The prophylactic antimicrobial success of this nutraceutical formula against SARS-CoV-2, FLU-A and RSV-A viruses, together with the common bacteria and fungi co-infections as present in human oral cavity, is expected to be valuable.

Bioactive compounds from nature: Antioxidants targeting cellular transformation in response to epigenetic perturbations induced by oxidative stress

Oxidative stress results from a persistent imbalance in oxidation levels that promotes oxidants, playing a crucial role in the early and sustained phases of DNA damage and genomic and epigenetic instability, both of which are intricately linked to the development of tumors. The molecular pathways contributing to carcinogenesis in this context, particularly those related to double-strand and single-strand breaks in DNA, serve as indicators of DNA damage due to oxidation in cancer cases, as well as factors contributing to epigenetic instability through ectopic expressions. Oxidative stress has been considered a therapeutic target for many years, and an increasing number of studies have highlighted the promising effectiveness of natural products in cancer treatment. In this regard, we present significant research on the therapeutic targeting of oxidative stress using natural molecules and underscore the essential role of oxidative stress in cancer. The consequences of stress, especially epigenetic instability, also offer significant therapeutic prospects. In this context, the use of natural epi-drugs capable of modulating and reorganizing the epigenetic network is beginning to emerge remarkably. In this review, we emphasize the close connections between oxidative stress, epigenetic instability, and tumor transformation, while highlighting the role of natural substances as antioxidants and epi-drugs in the anti-tumoral context.

Effects of Lamiaceae family plants and their bioactive ingredients on coronavirus-induced lung inflammation

Coronaviruses (CoVs) are a family of viruses that cause infection in respiratory and intestinal systems. Different types of CoVs, those responsible for the SARS-CoV and the new global pandemic of coronavirus disease 2019 in people, have been found. Some plants were used as food additives: spices and dietary and/or medicinal purposes in folk medicine. We aimed to provide evidence about possible effects of two Lamiaceae family plants on control or treatment of CoVs-induced inflammation. The keywords including coronaviruses, Thymus vulgaris, Zataria multiflora, thymol, carvacrol, antivirus, and anti-inflammatory and antioxidant effects were searched in various databases such as PubMed, Web of Sciences (ISI), and Google Scholar until September 2022. The medicinal herbs and their main ingredients, thymol and carvacrol, showed antiviral properties and reduced inflammatory mediators, including IL-1β; IL-6, and TNF-α, at both gene and protein levels but increased the levels of IFN-γ in the serum as anti-inflammatory cytokine. These medicinal herbs and their constituents also reduce oxidative stress and enhance antioxidant capacity. The results of molecular docking analyses also indicated that polyphenol components such as thymol, carvone, and carvacrol could inhibit the entry of the viruses into the host cells in molecular docking analyses. The antiviral, anti-inflammatory, and antioxidant effects of these plants may be due to actions of their phenolic compounds that modulate immune response and may be useful in the control and treatment of CoV-induced lung disorder.

Mesenchymal stem cell conditioned medium alleviates acute lung injury through KGF-mediated regulation of epithelial sodium channels

Acute lung injury (ALI) is a progressive inflammatory injury, and mesenchymal stem cells (MSCs) can be used to treat ALI. MSC-conditioned medium (MSC-CM) contains many cytokines, in which keratinocyte growth factor (KGF) is a soluble factor that plays a role in lung development. We aim to explore the protective effects of MSCs secreted KGF on ALI, and investigate the involvement of epithelial sodium channel (ENaC), which are important in alveolar fluid reabsorption. Both lipopolysaccharides (LPS)-induced mouse and alveolar organoid ALI models were established to confirm the potential therapeutic effect of MSCs secreted KGF. Meanwhile, the expression and regulation of ENaC were determined in alveolar type II epithelial (ATII) cells. The results demonstrated that MSC-CM and KGF could alleviate the extent of inflammation-related pulmonary edema in ALI mice, which was abrogated by a KGF neutralizing antibody. In an alveolar organoid ALI model, KGF in MSC-CM could improve the proliferation and decrease the differentiation of ATII cells. At the cellular level, the LPS-inhibited protein expression of ENaC could be reversed by KGF in MSC-CM. In addition, bioinformatics analysis and our experimental data provided the evidence that the NF-κB signaling pathway may be involved in the regulation of ENaC. Our research confirmed that the therapeutic effect of MSC-CM on edematous ALI was closely related to KGF, which may be involved in the proliferation and differentiation of ATII cells, as well as the upregulation of ENaC expression by the inhibition of NF-κB signaling pathway.

Effects of Ottonia anisum plant extract on local anesthetic, analgesic, anti-inflammatory and HCl‑induced acute lung injury activities: a study in animal models

Ottonia anisum (O. anisum), belonging to the family Piperaceae, is renowned for its medicinal properties. The plant is rich in alkaloids, terpenoids and flavonoids with recorded bioactivities. The stems, roots, and leaves, of the O. anisum have been extensively used in the folk medicine. Therefore, the present study was conducted to examine the pharmacological activities of O. anisum root extract. Methanolic root extract of O. anisum was assessed for local anesthetic, analgesic, anti-inflammatory and HCl-induced acute lung injury activities in animal models. Local anesthetic activity assessed in frog and guinea pigs through foot withdrawal reflex and intradermal wheal method, respectively, revealed the dose-dependent onset time of anesthesia response. In the case of HCl-induced ALI, the mice group orally administered with O. anisum extract were assessed for bronchoalveolar lavage fluid (BLF) contents, oxidative stress, and proinflammatory molecules. The analysis revealed the reduction in inflammatory molecules, neutrophils, and oxidative stress in the extract treated mice group. In addition, the redox homeostasis, reduced GSH and the catalase activity was found to be restored in the treated groups. Intriguingly, the genes associated with the NFkB expression was found to be downregulated in O. anisum extract treated groups. Moreover, the extract unveiled the significant analgesic and anti-inflammatory activities. Overall, the findings emphasize the clinical applicability of O. anisum extract in the treatment of ALI as well as the potential usage in local anesthetic, analgesic, and anti-inflammatory agents during the treatments.

Oxidative stress, hormones, and effects of natural antioxidants on intestinal inflammation in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic, relapsing gastrointestinal (GI) disorder characterized by intestinal inflammation. The etiology of IBD is multifactorial and results from a complex interplay between mucosal immunity, environmental factors, and host genetics. Future therapeutics for GI disorders, including IBD, that are driven by oxidative stress require a greater understanding of the cellular and molecular mechanisms mediated by reactive oxygen species (ROS). In the GI tract, oxidative stressors include infections and pro-inflammatory responses, which boost ROS generation by promoting the production of pro-inflammatory cytokines. Nuclear factor kappa B (NF-κB) and nuclear factor erythroid 2-related factor 2 (Nrf2) represent two important signaling pathways in intestinal immune cells that regulate numerous physiological processes, including anti-inflammatory and antioxidant activities. Natural antioxidant compounds exhibit ROS scavenging and increase antioxidant defense capacity to inhibit pro-oxidative enzymes, which may be useful in IBD treatment. In this review, we discuss various polyphenolic substances (such as resveratrol, curcumin, quercetin, green tea flavonoids, caffeic acid phenethyl ester, luteolin, xanthohumol, genistein, alpinetin, proanthocyanidins, anthocyanins, silymarin), phenolic compounds including thymol, alkaloids such as berberine, storage polysaccharides such as tamarind xyloglucan, and other phytochemicals represented by isothiocyanate sulforaphane and food/spices (such as ginger, flaxseed oil), as well as antioxidant hormones like melatonin that target cellular signaling pathways to reduce intestinal inflammation occurring with IBD.

RNF128 regulates neutrophil infiltration and myeloperoxidase functions to prevent acute lung injury

Acute lung injury (ALI) is characterised by severe pulmonary inflammation, alveolar-capillary barrier disruption, and pulmonary oedema. Therefore, establishing effective therapeutic targets for ALI prevention is crucial. The present study reports a novel function of RNF128 in regulating LPS-induced ALI. Severe lung damage and increased immune cell infiltration were detected in RNF128-deficient mice. In vitro experiments revealed that RNF128 inhibits neutrophil activation by binding to myeloperoxidase (MPO) and reducing its levels and activity. Moreover, RNF128 regulates alveolar macrophage activation and neutrophil infiltration by interacting with TLR4, targeting it for degradation, and inhibiting NF-κB activation, hence decreasing pro-inflammatory cytokines. Our results demonstrate for the first time that RNF128 is a negative regulator of MPO and TLR4 in neutrophils and alveolar macrophages, respectively. However, AAV9-mediated RNF128 overexpression alleviated lung tissue damage and reduced inflammatory cell infiltration. Thus, RNF128 is a promising therapeutic candidate for pharmacological interventions in ALI.

Pharmacologic effects approach of essential oils and their components on respiratory diseases

ETHNOPHARMACOLOGICAL RELEVANCE

Essential oils (EOs) are concentrated hydrophobic liquids with volatility and a unique aroma. Formed by aromatic plants as secondary metabolites, EOs have been used as traditional medicines to treat various health problems worldwide. Historical records show that herbs rich in EOs have been widely used to treat respiratory diseases in China, Europe, and many other regions.

AIM OF THE REVIEW

This review summarizes the traditional applications and modern pharmacological mechanisms of EOs derived from aromatic herbs and their active ingredients in respiratory diseases in preclinical and clinical trials through multitarget synergy.

MATERIALS AND METHODS

Information about EOs and respiratory diseases was collected from electronic databases, such as ScienceDirect, Web of Science, PubMed, Google Scholar, Baidu Scholar, and the China National Knowledge Infrastructure (CNKI).

RESULTS

This review presents the preventive and therapeutic effects of EOs on respiratory diseases, including chronic obstructive pulmonary disease, bronchial asthma, acute lung injury, pulmonary infection, and pulmonary fibrosis. The molecular mechanisms of EOs in treating different lung diseases are summarized, including anti-inflammation, anti-oxidation, mucolytic, and immune regulatory mechanisms.

CONCLUSIONS

EOs show potential as supplements or substitutes for treating lung diseases.

Anti-Inflammatory Activities of Arnica montana Planta Tota versus Flower Extracts: Analytical, In Vitro and In Vivo Mouse Paw Oedema Model Studies

Arnica montana is well known for its anti-inflammatory properties. While the anti-inflammatory activity of Arnica flowers (Arnicae flos) has been extensively studied, that of the whole plant (Arnicae planta tota) is less characterized. We compared the ability of Arnicae planta tota and Arnicae flos extracts to inhibit the pro-inflammatory NF-κB-eicosanoid pathway, using several in vitro and in vivo assays. We showed that Arnicae planta tota inhibited NF-κB reporter activation, with an IC₅₀ of 15.4 μg/mL (vs. 52.5 μg/mL for Arnicae flos). Arnicae planta tota also inhibited LPS-induced expression of ALOX5 and PTGS2 genes in human differentiated macrophages. ALOX5 and PTGS2 encode the 5-lipoxygenase (5-LO) and cyclooxygenase-2 (COX-2) enzymes that initialize the conversion of arachidonic acid into leukotrienes and prostaglandins, respectively. Arnicae planta tota inhibited 5-LO and COX-2 enzymatic activity in vitro and in human primary peripheral blood cells, with lower IC₅₀ compared to Arnicae flos. Finally, Arnicae planta tota applied topically reduced carrageenan-induced mouse paw oedema more efficiently than Arnicae flos. Altogether, Arnicae planta tota displayed a superior anti-inflammatory activity compared to Arnicae flos, suggesting that Arnicae-planta-tota-containing products might be more effective in alleviating the manifestations of acute inflammation than those based on Arnicae flos alone.

Thymus vulgaris, a natural pharmacy against COVID-19: A molecular review

Introduction

A worldwide pandemic infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of a deadly disease called COVID-19. Interaction of the virus and the Angiotensin converting-enzyme 2 (ACE2) receptor leads to an inflammatory-induced tissue damage. Thymus vulgaris L. (TvL) is a plant with a long history in traditional medicine that has antimicrobial, antiseptic, and antiviral properties. Thymol and Carvacrol are two important biological components in Thyme that have anti-inflammatory, antioxidant, and immunomodulatory properties. This study is a molecular review on the potential effects of TvL and its active compounds on SARS-COV2 infection.

Method

This is a narrative review in which using PubMed, Scopus, ISI, Cochrane, ScienceDirect, Google scholar, and Arxiv preprint databases, the molecular mechanisms of therapeutic and protective effects of TvL and its active compounds have been discussed regarding the molecular pathogenesis in COVID-19.

Results

Thyme could suppress TNF-alpha, IL-6, and other inflammatory cytokines. It also enhances the anti-inflammatory cytokines like TGF-beta and IL-10. Thyme extract acts also as an inhibitor of cytokines IL-1-beta and IL-8, at both mRNA and protein levels. Thymol may also control the progression of neuro-inflammation toward neurological disease by reducing some factors. Thyme and its active ingredients, especially Thymol and Carvacrol, have also positive effects on the renin-angiotensin system (RAS) and intestinal microbiota.

Conclusions

Accordingly, TvL and its bioactive components may prevent COVID-19 complications and has a potential protective role against the deleterious consequences of the disease.

Shufeng Jiedu capsule inhibits inflammation and apoptosis by activating A2AAR and inhibiting NF-κB to alleviate LPS-induced ALI

ETHNOPHARMACOLOGICAL RELEVANCE

Shufeng Jiedu capsule (SFJDC) is a pure form of traditional Chinese medicine (TCM) that contains eight medicinal plants. Known for its anti-inflammatory and antipyretic effects, it is mostly used to treat upper respiratory tract infections and other infectious diseases, such as colds, pharyngitis, laryngitis, and tonsillitis. Both acute lung injury (ALI) and COVID-19 are closely related to lung damage, primarily manifesting as lung inflammation and epithelial cell damage. However, whether SFJDC can improve ALI and by what mechanism remain unclear. The purpose of this study was to explore whether SFJDC could be used as a prophylactic treatment for COVID-19 by improving acute lung injury.

AIM OF THE STUDY

The purpose of this study was to determine whether SFJDC could protect against ALI caused by lipopolysaccharide (LPS), and we wanted to determine how SFJDC reduces inflammation and apoptosis pharmacologically and molecularly.

MATERIALS AND METHODS

Preadministering SFJDC at 0.1 g/kg, 0.3 g/kg, or 0.5 g/kg for one week was followed by 5 mg/kg LPS to induce ALI in mice. Observations included the study of lung histomorphology, tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) secretion, as well as the ratio of lung wet/dry weights. In addition, RAW264.7 cells were treated for 24 h with 1 μg/mL LPS after being pretreated for 1 h with 0.5 mg/mL SFJDC. In the samples, we detected TNF-α, IL-1β, and IL-6. Cell apoptosis was detected by stimulating A549 cells for 24 h with RAW264.7 supernatant. Both in vitro and in vivo, the levels of A2A adenosine receptor (A2AAR), PKA, IκB, p-IκB, NF-κB P65 (P65), p-NF-κB P65 (p-P65), cleaved caspases-3 (Cc3), Bcl-2 associated X protein (Bax), and B-cell lymphoma-2 (Bcl-2) proteins were determined using Western blot analysis.

RESULTS

Lung tissue morphology was improved as SFJDC decreased cytokine secretion, the ratio of lung wet/dry weights, and lung tissue secretion of proinflammatory cytokines. The expression of A2AAR was increased by SFJDC, and the phosphorylation of NF-κB was inhibited. TUNEL staining and flow cytometry showed that SFJDC inhibited apoptosis by reducing the expression of Cc3 and the ratio of Bax/Bcl-2.

CONCLUSIONS

According to the results of this study, SFJDC can reduce inflammation and inhibit apoptosis. A2AAR activation and regulation of NF-κB expression are thought to make SFJDC anti-inflammatory and anti-apoptotic. A wide range of active ingredients may result in an anti-inflammatory and antipyretic effect with SFJDC.

Hydrogen gas alleviates lipopolysaccharide-induced acute lung injury and inflammatory response in mice

Background

Chronic inflammation and oxidant/antioxidant imbalance are two main pathological features associated with lipopolysaccharide (LPS)-induced acute lung injury (ALI). The following study investigated the protective role of hydrogen (H₂), a gaseous molecule without known toxicity, in LPS-induced lung injury in mice and explored its potential molecular mechanisms.

Methods

Mice were randomly divided into three groups: H₂ control group, LPS group, and LPS + H₂ group. The mice were euthanized at the indicated time points, and the specimens were collected. The 72 h survival rates, cytokines contents, pathological changes, expression of Toll-like receptor 4 (TLR4), and oxidative stress indicators were analyzed. Moreover, under different culture conditions, RAW 264.7 mouse macrophages were used to investigate the potential molecular mechanisms of H₂ in vitro. Cells were divided into the following groups: PBS group, LPS group, and LPS + H₂ group. The cell viability, intracellular ROS, cytokines, and expression of TLR4 and nuclear factor kappa-B (NF-κB) were observed.

Results

Hydrogen inhalation increased the survival rate to 80%, reduced LPS-induced lung damage, and decreased inflammatory cytokine release in LPS mice. Besides, H₂ showed remarked anti-oxidative activity to reduce the MDA and NO contents in the lung. In vitro data further indicated that H₂ down-regulates the levels of ROS, NO, TNF-α, IL-6, and IL-1β in LPS-stimulated macrophages and inhibits the expression of TLR4 and the activation of nuclear factor kappa-B (NF-κB).

Conclusion

Hydrogen gas alleviates lipopolysaccharide-induced acute lung injury and inflammatory response most probably through the TLR4-NF-κB pathway.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12950-022-00314-x.

A systematic review and meta-analysis of the effect of thymol as an anti-inflammatory and wound healing agent: A review of thymol effect on inflammation and wound healing: A review of thymol effect on inflammation and wound healing

Thymol (THY) exhibits antibacterial and antioxidant properties. Recent studies have also shown that THY presents anti-inflammatory and healing properties. This review focused on in vitro and in vivo investigations related to THY utilization, as an anti-inflammatory and/or wound healing agent. PubMed, WebOfScience, and Scopus were examined. Independent reviewers conducted all diagram steps. PRISMA was followed for data extraction. RoB 2 and SYRCLE were utilized to assess the risk of bias for in vitro and animal studies. Meta-analysis was performed for in vitro and in vivo articles that investigated THY as an anti-inflammatory agent. Thirty-six and 15 articles were included in the qualitative analysis and meta-analysis, respectively. Studies showed high risk of bias related to sampling, allocation procedures, randomization, and blinding. Even so, for in vitro studies, significant result was observed for IL-2. For in vivo studies, significant results were found for IL-1, IL-17, TNF-α, AST, MPO, and CRP, with higher levels noticed in control groups. THY presents significant properties as anti-inflammatory, ameliorating affections of the digestive system, cardiovascular problems, respiratory system and dermal damages, and burns. Researches are needed to clarify THY dose-response relationship and its mechanism of action, especially in the application of THY as a healing agent.

Experimental and Clinical Studies on the Effects of Natural Products on Noxious Agents-Induced Lung Disorders, a Review

The harmful effects of various noxious agents (NA) are well-known and there are reports regarding the induction of various lung disorders due to exposure to these agents both in animal and human studies. In addition, various studies have shown the effects of natural products (NP) on NA-induced lung disorders. The effects of various NP, including medicinal plants and their derivatives, on lung injury induced by NA, were reviewed in this study. The improving effects of various NP including medicinal plants, such as Aloe vera, Anemarrhena asphodeloides, Avena sativa, Crocus sativus, Curcuma longa, Dioscorea batatas, Glycyrrhiza glabra, Gentiana veitchiorum, Gentiopicroside, Houttuynia cordata, Hibiscus sabdariffa, Hochu-ekki-to, Hippophae rhamnoides, Juglans regia, Melanocarpa fruit juice, Mikania glomerata, Mikania laevigata, Moringa oleifera, Myrtus communis L., Lamiaceae, Myrtle, Mosla scabra leaves, Nectandra leucantha, Nigella sativa, Origanum vulgare L, Pulicaria petiolaris, Paulownia tomentosa, Pomegranate seed oil, Raphanus sativus L. var niger, Rosa canina, Schizonepeta tenuifolia, Thymus vulgaris, Taraxacum mongolicum, Tribulus Terrestris, Telfairia occidentalis, Taraxacum officinale, TADIOS, Xuebijing, Viola yedoensis, Zataria multiflora, Zingiber officinale, Yin-Chiao-San, and their derivatives, on lung injury induced by NA were shown by their effects on lung inflammatory cells and mediators, oxidative stress markers, immune responses, and pathological changes in the experimental studies. Some clinical studies also showed the therapeutic effects of NP on respiratory symptoms, pulmonary function tests (PFT), and inflammatory markers. Therefore, the results of this study showed the possible therapeutic effects of various NP on NA-induced lung disorders by the amelioration of various features of lung injury. However, further clinical studies are needed to support the therapeutic effects of NP on NA-induced lung disorders for clinical practice purposes.

Plant-Derived Natural Products as Lead Agents against Common Respiratory Diseases

Never has the world been more challenged by respiratory diseases (RDs) than it has witnessed in the last few decades. This is evident in the plethora of acute and chronic respiratory conditions, ranging from asthma and chronic obstructive pulmonary disease (COPD) to multidrug-resistant tuberculosis, pneumonia, influenza, and more recently, the novel coronavirus (COVID-19) disease. Unfortunately, the emergence of drug-resistant strains of pathogens, drug toxicity and side effects are drawbacks to effective chemotherapeutic management of RDs; hence, our focus on natural sources because of their unique chemical diversities and novel therapeutic applications. This review provides a summary on some common RDs, their management strategies, and the prospect of plant-derived natural products in the search for new drugs against common respiratory diseases.

ROCK inhibitor fasudil reduces the expression of inflammatory factors in LPS-induced rat pulmonary microvascular endothelial cells via ROS/NF-κB pathway

Background

Inflammation plays a major role in the pulmonary artery hypertension (PAH) and the acute lung injury (ALI) diseases. The common feature of these complications is the dysfunction of pulmonary microvascular endothelial cells (PMVECs). Fasudil, the only Rho kinase (ROCK) inhibitor used in clinic, has been proved to be the most promising new drug for the treatment of PAH, with some anti-inflammatory activity. Therefore, in the present study, the effect of fasudil on lipopolysaccharide (LPS)-induced inflammatory injury in rat PMVECs was investigated.

Methods

LPS was used to make inflammatory injury model of rat PMVECs. Thereafter, the mRNA and protein expression of pro-inflammatory factors was evaluated by reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) assay respectively. Intracellular reactive oxygen species (ROS) levels were measured by the confocal laser scanning system. The activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and the content of malondialdehyde (MDA) were determined by using commercial kits according to the manufacturer’s instructions. Western blot assay was used to detect the protein expression of nuclear factor kappa B (NF-κB) p65.

Results

Fasudil effectively prevented inflammatory injury induced by LPS, which is manifested by the decrease of pro-inflammatory cytokines interleukin-6 (IL-6) and monocyte chenotactic protein-1 (MCP-1). Meanwhile, fasudil dramatically reduced the levels of ROS and MDA, and also elevated the activities of SOD and GSH-Px. Furthermore, the nuclear translocation of NF-κB p65 induced by LPS was also suppressed by fasudil. Additionally, the ROS scavengers N-Acetylcysteine (N-Ace) was also found to inhibit the nuclear translocation of NF-κB and the mRNA expression of IL-6 and MCP-1 induced by LPS, which suggested that ROS was essential for the nuclear translocation of NF-κB.

Conclusions

The present study revealed that fasudil reduced the expression of inflammatory factors, alleviated the inflammatory and oxidative damage induced by LPS in rat PMVECs via ROS-NF-κB signaling pathway.

Physalin B ameliorates inflammatory responses in lipopolysaccharide-induced acute lung injury mice by inhibiting NF-κB and NLRP3 via the activation of the PI3K/Akt pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Physalin B (PB) is an active constituent of Physalis alkekengi L. var. Franchetii, which is a traditional medicine for clearing heat and detoxification, resolving phlegm, and diuresis. It has been commonly applied to treat sore throat, phlegm-heat, cough, dysuria, pemphigus, and eczema.

AIM OF STUDY

Physalin B has shown efficacy as an anti-acute lung injury (ALI) agent previously; however, its mechanisms of action remain unclear. In the present study, we established a lipopolysaccharide-induced septic ALI model using BALB/c mice to further confirm the therapeutic potential of PB and to assess the underlying molecular mechanisms.

MATERIALS AND METHODS

We used 75% ethanol and macroporous resin for extraction, separation, and enrichment of PB. The LPS-induced ALI mouse model was used to determine anti-inflammatory effects of PB. The severity of acute lung injury was evaluated by hematoxylin and eosin staining, wet/dry lung ratio, and myeloperoxidase (MPO) activity in lung tissue. An automatic analyzer was used to measure the arterial blood gas index. Protein levels of pro-inflammatory cytokines in serum, bronchoalveolar lavage fluid (BALF), and lung tissue was measured using an ELISA. Quantitative RT-PCR was used to measure changes in RNA levels of pro-inflammatory cytokines in the lungs. A fluorometric assay kit was used for determination of apoptosis-related factors to assess anti-apoptotic effects of PB. Western blotting was used to assess levels of key pathway proteins and apoptosis-related proteins. Connections between the pathways were tested through inhibitor experiments.

RESULTS

Pretreatment with PB (15 mg kg^-1 d^-1, i.g.) significantly reduced lung wet/dry weight ratios and MPO activity in blood and BALF of ALI mice, and it alleviated LPS-induced inflammatory cell infiltration in lung tissue. The levels of pro-inflammatory factors TNF-α, IL-6, and IL-1β and their mRNA levels in blood, BALF, and lung tissue were reduced following PB pretreatment. PB pretreatment also downregulated the apoptotic factors caspase-3, caspase-9, and apoptotic protein Bax, and it upregulated apoptotic protein Bcl-2. The NF-κB and NLRP3 pathways were inhibited through activation of the PI3K/Akt pathway due to PB pretreatment, whereas administration of PI3K inhibitors increased activation of these pathways.

CONCLUSIONS

Taken together, our results suggest that the anti-ALI properties of PB are closely associated with the inactivation of NF-κB and NLRP3 by altering the PI3K/Akt pathway. Furthermore, our findings provide a novel strategy for application of PB as a potential agent for treating patients with ALI. To the best of our knowledge, this is the first study to elucidate the underlying mechanism of action of PB against ALI.

Preclinical and Clinical Antioxidant Effects of Natural Compounds against Oxidative Stress-Induced Epigenetic Instability in Tumor Cells

ROS (reactive oxygen species) are produced via the noncomplete reduction in molecular oxygen in the mitochondria of higher organisms. The produced ROS are placed in various cell compartments, such as the mitochondria, cytoplasm, and endoplasmic reticulum. In general, there is an equilibrium between the synthesis of ROS and their reduction by the natural antioxidant defense system, called the redox system. Therefore, when this balance is upset, the excess ROS production can affect different macromolecules, such as proteins, lipids, nucleic acids, and sugars, which can lead to an electronic imbalance than oxidation of these macromolecules. Recently, it has also been shown that ROS produced at the cellular level can affect different signaling pathways that participate in the stimulation of transcription factors linked to cell proliferation and, consequently, to the carcinogenesis process. Indeed, ROS can activate the pathway of tyrosine kinase, MAP kinase, IKK, NF-KB, phosphoinositol 3 phosphate, and hypoxia-inducible factor (HIF). The activation of these signaling pathways directly contributes to the accelerated proliferation process and, as a result, the appearance of cancer. In addition, the use of antioxidants, especially natural ones, is now a major issue in the approach to cancer prevention. Some natural molecules, especially phytochemicals isolated from medicinal plants, have now shown interesting preclinical and clinical results.

Thyme oil alleviates Ova-induced bronchial asthma through modulating Th2 cytokines, IgE, TSLP and ROS

Bronchial asthma (BA) is a heterogeneous allergic respiratory disease with diverse inflammatory symptoms, pathology, and responses to treatment. Thyme is a natural product which is consisted of multiple phenolic compounds of therapeutic significance for treatment of cough and bronchitis. This study evaluated the efficacy of thyme oil against ovalbumin (OVA)-induced BA in an experimental rabbit model. Forty male rabbits were divided into four equal groups [control group (G1), OVA (G2), thyme oil (G3), and OVA plus thyme oil (G4)]. Animals were treated for 30 days, and clinical, histopathological (HP), histochemical (HC), immunohistochemical (IHC), morphometric, biochemical and flow cytometry methods were performed, followed by statistical analysis. All used methods revealed normal structure of the lung tissues in rabbits of G1 and G3. In contrast, the clinical examination of G2 rabbits revealed an obvious increase in the respiratory rate, sneezing and wheezing, whereas the HP, HC and IHC techniques exhibited substantial inflammatory changes in the peribronchio-vascular lung tissues with thinning, degeneration, apoptosis (using the TUNEL assay), necrosis, and shedding of the airway epithelium. Furthermore, the morphometric results confirmed significant increases in the numbers of inflammatory cells, goblet cells, eosinophils and apoptotic cells from (12, 0, 2, 2 cells) to (34,10, 16, 18 cells) respectively, as well as the area percentage of collagen fiber deposition and immunoexpression of eotaxin-1/10 high power fields. Additionally, the biochemical results revealed significant increases in the serum levels of TSLP, IL-4, IL-5, IL-9, IL-13, IgE and eotaxin-1 cytokines from (140, 40, 15, 38, 120, 100, 48) pg./ml to (360, 270, 130, 85, 365, 398, 110) pg./ml respectively, while analysis of ROS by flow cytometry revealed remarkable oxidative stress effects in G2 rabbits. On the other hand, treatment of rabbits with thyme oil in G4 substantially alleviated all OVA-induced alterations. Overall, our findings indicate for the first time that thyme oil can ameliorate OVA-induced BA via its immunomodulatory, anti-inflammatory, antiapoptotic, and antioxidant effects on the lung tissues of rabbits.

Thymol alleviates AGEs-induced podocyte injury by a pleiotropic effect via NF-κB-mediated by RhoA/ROCK signalling pathway

Advanced glycation end products (AGE) are those of the most powerful pathogenic factors that related to diabetic complications. In our study, we investigated the beneficial effects of thymol on AGE induced cell injury and apoptosis in human podocytes (HPCs) and attempted to clarify its mechanisms. Our results revealed that stimulation with AGE could significantly activate RhoA/NF-κB pathway. Results showed thymol could markedly suppress inflammatory responses, cell apoptosis and disordered cytoskeleton. Also thymol restored the expression of podocin, restrained migration capacity. Western blot analysis indicated that it could restore the expression of RhoA, ROCK and vimentin, nephrin, podocin and p65 and IκBα phosphorylation. Moreover, si-RhoA also suppressed the expression of pro-inflammatory cytokines, ROCK, and vimentin and the phosphorylation of p65 and IκBα. In conclusion, thymol inhibits AGE-induced cell injury in HPCs by suppressing the RhoA-NF-κB pathway and may be apromising therapeutic agent.

Targeting Multiple Signal Transduction Pathways of SARS-CoV-2: Approaches to COVID-19 Therapeutic Candidates

Due to the complicated pathogenic pathways of coronavirus disease 2019 (COVID-19), related medicinal therapies have remained a clinical challenge. COVID-19 highlights the urgent need to develop mechanistic pathogenic pathways and effective agents for preventing/treating future epidemics. As a result, the destructive pathways of COVID-19 are in the line with clinical symptoms induced by severe acute coronary syndrome (SARS), including lung failure and pneumonia. Accordingly, revealing the exact signaling pathways, including inflammation, oxidative stress, apoptosis, and autophagy, as well as relative representative mediators such as tumor necrosis factor-α (TNF-α), nuclear factor erythroid 2-related factor 2 (Nrf2), Bax/caspases, and Beclin/LC3, respectively, will pave the road for combating COVID-19. Prevailing host factors and multiple steps of SARS-CoV-2 attachment/entry, replication, and assembly/release would be hopeful strategies against COVID-19. This is a comprehensive review of the destructive signaling pathways and host-pathogen interaction of SARS-CoV-2, as well as related therapeutic targets and treatment strategies, including potential natural products-based candidates.

Effect of gut microbiota on LPS-induced acute lung injury by regulating the TLR4/NF-kB signaling pathway

Acute lung injury (ALI) is a common acute respiratory disease treated in the clinic. Intestinal microflora disorder affect lung diseases through the gut-lung axis. In this study, we explored the regulatory mechanism of the gut flora in the host defense against lipopolysaccharide (LPS)-induced ALI through the TLR4/NF-kB pathway by constructing a gut microflora dysbiosis-model with antibiotic administration and reconstruction of the intestinal microecology. Then, high-throughput sequencing was performed, and the levels of secreted IgA (sIgA), β-defensins, and Muc2 were measured to assess the gut flora and mucosal barrier. The expression of TLR4, NF-kB, TNF-α, IL-1β, oxidative stress and the lung wet/dry (W/D) ratio were evaluated to assess lung damage. Hematoxylin and eosin (HE) staining was performed to evaluate the damage to the gut and lung tissues. Accordingly, gut microbiota imbalance may regulate the TLR4/NF-kB signaling pathway in the lung immune system, activating oxidative stress in the lung and mediating lung injury through the regulation of the gut barrier. However, fecal microbiota transplantation (FMT) impairs the activity of the TLR4/NF-kB signaling pathway in the lung and decreases oxidative stress in animals with ALI by restoring the gut microecology. CONCLUSIONS: Our results indicated the protective effect of gut flora in regulating immunity of LPS-induced ALI by modulating the TLR4/NF-kB signaling pathway which may induce inflammation and oxidative stress.

Eugenol mitigated acute lung but not spermatic toxicity of C60 fullerene emulsion in mice

C₆₀ fullerene (C₆₀) is a nano-pollutant that can damage the respiratory system. Eugenol exhibits significant anti-inflammatory and antioxidant properties. We aimed to investigate the time course of C₆₀ emulsion-induced pulmonary and spermatic harms, as well as the effect of eugenol on C₆₀ emulsion toxicity. The first group of mice (protocol 1) received intratracheally C₆₀ emulsion (1.0 mg/kg BW) or vehicle and were tested at 12, 24, 72 and 96 h (F groups) thereafter. The second group of mice (protocol 2) received intratracheally C₆₀ emulsion or vehicle, 1 h later were gavaged with eugenol (150 mg/kg) or vehicle, and experiments were done 24 h after instillation. Lung mechanics, morphology, redox markers, cytokines and epididymal spermatozoa were analyzed. Protocol 1: Tissue damping (G) and elastance (H) were significantly higher in F24 than in others groups, except for H in F72. Morphological and inflammatory parameters were worst at 24 h and subsequently declined until 96 h, whereas redox and spermatic parameters worsened over the whole period. Eugenol eliminated the increase in G, H, cellularity, and cytokines, attenuated oxidative stress induced by C60 exposure, but had no effect on sperm. Hence, exposure to C₆₀ emulsion deteriorated lung morphofunctional, redox and inflammatory characteristics and increased the risk of infertility. Furthermore, eugenol avoided those changes, but did not prevent sperm damage.

Natural product derived phytochemicals in managing acute lung injury by multiple mechanisms

Acute lung injury (ALI) and its more severe form, acute respiratory distress syndrome (ARDS) as common life-threatening lung diseases with high mortality rates are mostly associated with acute and severe inflammation in lungs. With increasing in-depth studies of ALI/ARDS, significant breakthroughs have been made, however, there are still no effective pharmacological therapies for treatment of ALI/ARDS. Especially, the novel coronavirus pneumonia (COVID-19) is ravaging the globe, and causes severe respiratory distress syndrome. Therefore, developing new drugs for therapy of ALI/ARDS is in great demand, which might also be helpful for treatment of COVID-19. Natural compounds have always inspired drug development, and numerous natural products have shown potential therapeutic effects on ALI/ARDS. Therefore, this review focuses on the potential therapeutic effects of natural compounds on ALI and the underlying mechanisms. Overall, the review discusses 159 compounds and summarizes more than 400 references to present the protective effects of natural compounds against ALI and the underlying mechanism.

Phytochemicals: Potential Therapeutic Interventions Against Coronavirus-Associated Lung Injury

Since the outbreak of coronavirus disease 2019 (COVID-19) in December 2019, millions of people have been infected and died worldwide. However, no drug has been approved for the treatment of this disease and its complications, which urges the need for finding novel therapeutic agents to combat. Among the complications due to COVID-19, lung injury has attained special attention. Besides, phytochemicals have shown prominent anti-inflammatory effects and thus possess significant effects in reducing lung injury caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Also, the prevailing evidence reveales the antiviral effects of those phytochemicals, including anti-SARS-CoV activity, which could pave the road in providing suitable lead compounds in the treatment of COVID-19. In the present study, candidate phytochemicals and related mechanisms of action have been shown in the treatment/protection of lung injuries induced by various methods. In terms of pharmacological mechanism, phytochemicals have shown potential inhibitory effects on inflammatory and oxidative pathways/mediators, involved in the pathogenesis of lung injury during COVID-19 infection. Also, a brief overview of phytochemicals with anti-SARS-CoV-2 compounds has been presented.

Cardioprotective effect of thymol against adrenaline-induced myocardial injury in rats

Cardiovascular disease represents a vital global disease burden. This study aims to assess the possible cardioprotective effect of thymol against adrenaline-induced myocardial injury (MI) in rats. Furthermore the effect of thymol on cardiac function biomarkers, electrocardiogram (ECG) alterations, oxidative stress, inflammation, apoptosis and histopathological changes was assessed. MI was induced by adrenaline (2 mg/kg, s.c.) injected as a single dose for 2 consecutive days (24 h apart). Normal and control groups received the vehicle for 21 consecutive days. The other 3 groups were orally administered thymol (15, 30, 60 mg/kg) for 21 consecutive days and on day 22, adrenaline was injected as a single dose for 2 consecutive days. Then ECG examination, biochemical, histopathological, immunohistochemical analyses were carried out. Thymol reversed adrenaline-induced reduction of heart rate, prolongation of RR interval and elevation of ST interval. Thymol pretreatment significantly reduced serum aspartate dehydrogenase (AST), lactate dehydrogenase (LDH), and creatine kinase (CK) levels in MI rats. Oral pretreatment with thymol increased reduced glutathione (GSH), reduced malondialdehyde (MDA), nuclear factor-kappa B (NF-κB), and interleukin-1β (IL-1β) cardiac contents in MI rats. Additionally, thymol administration significantly decreased protein expression of caspase-3, increased Bcl-2 protein expression in cardiac tissue and ameliorated histopathological changes. This study reveals that thymol exerted cardioprotective effect against adrenaline-induced MI in rats evidenced by improving cardiac function, attenuating ECG and histopathological changes which may be partly mediated through its anti-oxidant, anti-inflammatory and anti-apoptotic effect.

Plants derived therapeutic strategies targeting chronic respiratory diseases: Chemical and immunological perspective

The apparent predicament of the representative chemotherapy for managing respiratory distress calls for an obligatory deliberation for identifying the pharmaceuticals that effectively counter the contemporary intricacies associated with target disease. Multiple, complex regulatory pathways manifest chronic pulmonary disorders, which require chemotherapeutics that produce composite inhibitory effect. The cost effective natural product based molecules hold a high fervor to meet the prospects posed by current respiratory-distress therapy by sparing the tedious drug design and development archetypes, present a robust standing for the possible replacement of the fading practice of poly-pharmacology, and ensure the subversion of a potential disease relapse. This study summarizes the experimental evidences on natural products moieties and their components that illustrates therapeutic efficacy on respiratory disorders.

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Plant derived therapeutics for managing chronic respiratory disorders.

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Activity of natural product based molecules on key regulatory pathways of COPD.

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Preclinical evidence for the efficacy of natural product moieties.

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Clinical significance of plant derived molecules in pulmonary distress.

Ethanolic Extract of Moringa oleifera Leaves Influences NF-κB Signaling Pathway to Restore Kidney Tissue from Cobalt-Mediated Oxidative Injury and Inflammation in Rats

This study aimed to describe the protective efficacy of Moringa oleifera ethanolic extract (MOEE) against the impact of cobalt chloride (CoCl₂) exposure on the rat’s kidney. Fifty male rats were assigned to five equal groups: a control group, a MOEE-administered group (400 mg/kg body weight (bw), daily via gastric tube), a CoCl₂-intoxicated group (300 mg/L, daily in drinking water), a protective group, and a therapeutic co-administered group that received MOEE prior to or following and concurrently with CoCl₂, respectively. The antioxidant status indices (superoxide dismutase (SOD), catalase (CAT), and reduced glutathione (GSH)), oxidative stress markers (hydrogen peroxide (H₂O₂), 8-hydroxy-2-deoxyguanosine (8-OHdG), and malondialdehyde (MDA)), and inflammatory response markers (nitric oxide (NO), tumor necrosis factor (TNF-α), myeloperoxidase (MPO), and C-reactive protein (CRP)) were evaluated. The expression profiles of pro-inflammatory cytokines (nuclear factor-kappa B (NF-kB) and interleukin-6 (IL-6)) were also measured by real-time quantitative polymerase chain reaction (qRT-PCR). The results showed that CoCl₂ exposure was associated with significant elevations of oxidative stress and inflammatory indices with reductions in the endogenous tissue antioxidants’ concentrations. Moreover, CoCl₂ enhanced the activity of the NF-κB inflammatory-signaling pathway that plays a role in the associated inflammation of the kidney. MOEE ameliorated CoCl₂-induced renal oxidative damage and inflammatory injury with the suppression of the mRNA expression pattern of pro-inflammatory cytokine-encoding genes. MOEE is more effective when it is administered with CoCl₂ exposure as a prophylactic regimen. In conclusion, MOEE administration exhibited protective effects in counteracting CoCl₂-induced renal injury in rats.

Hesperetin ameliorates lipopolysaccharide-induced acute lung injury in mice through regulating the TLR4-MyD88-NF-κB signaling pathway

Hesperetin, a major bioflavonoid in sweet oranges and lemons, exerts an anti-inflammatory effect in pulmonary diseases; however, its effect on lipopolysaccharide (LPS)-induced acute lung injury is unclear. This study investigated the effect of hesperetin on LPS-induced lung inflammatory response. Mice were intratracheally instilled with 5 mg/kg body weight LPS, and then were given hesperetin orally (10, 20, and 30 mg/kg body weight) 1 h later. Hesperetin dramatically suppressed the levels of interleukin-6 and tumor necrosis factor-α, as well as the number of inflammatory cells in bronchoalveolar lavage fluid. Besides, it reduced lung injury, wet weight/dry weight ratio, and myeloperoxidase and lactate dehydrogenase activities, and enhanced superoxide dismutase activity. In addition, hesperetin significantly downregulated the Toll-like receptor 4 (TLR4) and myeloid differentiation factor 88 (MyD88) protein expression and suppressed nuclear factor-kappa B (NF-κB) activation in lung tissue. Together, these results indicated that the anti-inflammatory effect of hesperetin is associated with the TLR4-MyD88-NF-κB pathway, and that hesperetin shows therapeutic potential for LPS-induced acute lung injury.

TIPE2 ameliorates lipopolysaccharide-induced apoptosis and inflammation in acute lung injury

Objective

Tumour necrosis factor-α-induced protein 8-like 2 (TIPE2) has strong anti-inflammatory properties. However, it is unknown whether increased TIPE2 is protective against lipopolysaccharide (LPS)-induced ALI. In the current study, we aimed to investigate whether increased TIPE2 can exert protective effects in a mouse model of ALI induced by LPS.

Methods

We administered TIPE2 adeno-associated virus (AAV-TIPE2) intratracheally into the lungs of mice. Three weeks later, ALI was induced by intratracheal injection of LPS into BALB/c mice. Twenty-four hours later, lung bronchoalveolar lavage fluid (BALF) was acquired to analyse cells and protein, arterial blood was collected for arterial blood gas analysis and the determination of pro-inflammatory factor levels, and lung issues were collected for histologic examination, transmission electron microscopy (TEM), TUNEL staining, wet/dry (W/D) weight ratio analysis, myeloperoxidase (MPO) activity analysis and blot analysis of protein expression.

Results

We found that TIPE2 overexpression markedly mitigated LPS-induced lung injury, which was evaluated by the deterioration of histopathology, histologic scores, the W/D weight ratio, and total protein expression in the BALF. Moreover, TIPE2 overexpression markedly attenuated lung inflammation, as evidenced by the downregulation of polymorphonuclear neutrophils (PMNs) in the BALF, lung MPO activity, and pro-inflammatory cytokine levels in the serum. Moreover, TIPE2 overexpression not only dramatically prevented LPS-induced pulmonary cell apoptosis in mice but also blocked LPS-activated JNK phosphorylation and NF-κB p65 nuclear translocation.

Conclusions

Our study shows that the increased expression of AAV-mediated TIPE2 in the lungs of mice inhibits acute inflammation and apoptosis and suppresses the activation of NF-κB and JNK in a murine model of ALI.

Dexmedetomidine ameliorates LPS induced acute lung injury via GSK-3β/STAT3-NF-κB signaling pathway in rats

Acute lung injury (ALI) is a serious complication of sepsis and an important cause of death in intensive care. Studies have shown that DEX can inhibit inflammation. However, the anti-inflammatory effect and protective mechanism of DEX in lipopolysaccharide (LPS) induced ALI are still unclear. ALI model was established by intraperitoneal injection of LPS (10 mg/kg) in Sprague-Dawley (SD) male rats. Firstly, at 4, 6, 8, 12 and 24 h after LPS treatment, lung injury including pathologic histology, lung edema, and inflammation were detected. The optimal time point for lung injury was determined to be 12 h, at which time DEX was added to further test. Furthermore, STAT3 inhibitor (NSC74859) and GSK-3β inhibitor (SB216763) were added to verify the role of STAT3, GSK-3β and NF-κB in ameliorated ALI. Our results show that DEX pretreatment significantly decreased lung Wet-to-Dry weight (W/D) ratio and MPO activity and ameliorated LPS induced lung histopathological alterations. In addition, we confirmed that DEX can increased the phosphorylation of STAT3 and GSK-3β, and inhibit the phosphorylation of nuclear factor-κB (NF-κB) p65 in the inflammatory response induced by LPS. What's more, NSC74859 inhibited the phosphorylation of STAT3 and reversed the protect effect of DEX on LPS. SB216763 inhibited the phosphorylation of NF-κB and reversed the damage effect of LPS and plays the same anti-inflammatory effect as DEX. In summary, our data demonstrated that DEX can ameliorate ALI induced by LPS through GSK-3β/STAT3-NF-κB pathway.

Inhibitory effects of thymol on the cytotoxicity and inflammatory responses induced by Staphylococcus aureus extracellular vesicles in cultured keratinocytes

Staphylococcus aureus extracellular vesicles (EVs) deliver effector molecules to host cells and induce host cell pathology. This study investigated the disruption of S. aureus EVs by thymol along with its inhibitory effects on the cytotoxicity and inflammatory responses induced by EVs derived from two different S. aureus strains in cultured keratinocytes. Membrane disruption of the S. aureus EVs treated with thymol was determined using transmission electron microscopy. Human keratinocyte HaCaT cells were incubated with either intact or thymol-treated S. aureus EVs and then analyzed for cytotoxicity and pro-inflammatory cytokine gene expression. Thymol inhibited the growth of S. aureus strains and disrupted the membranes of the S. aureus EVs. The cytotoxicity and the expression levels of the pro-inflammatory cytokine genes towards HaCaT cells differed between the EVs derived from two S. aureus strains. Thymol-treated S. aureus EVs inhibited the cytotoxicity and the expression of the pro-inflammatory cytokine genes when compared to intact S. aureus EVs. Thymol-treated S. aureus EVs delivered lesser amounts of the EV component to host cells than intact EVs. Our results suggest that the thymol-induced disruption of the S. aureus EVs inhibits the delivery of effector molecules to host cells, resulting in the suppression of cytotoxicity and inflammatory responses in keratinocytes. Thymol may attenuate the host cell pathology induced by an S. aureus infection via both the antimicrobial activity against the bacteria and the disruption of the secreted EVs.

Apigenin C-glycosides of Microcos paniculata protects lipopolysaccharide induced apoptosis and inflammation in acute lung injury through TLR4 signaling pathway

Acute lung injury (ALI) and its more severe form acute respiratory distress syndrome (ARDS) are life-threatening conditions with high morbility and mortality, underscoring the urgent need for novel treatments. Leaves of the medicinal herb Microcos paniculata have been traditionally used for treating upper airway infections, by virtue of its content of flavonoids such as apigenin C-glycosides (ACGs). C-glycosides have been shown to exert strong anti-inflammatory properties, although their mechanism of action remains unknown. Herein, hypothesizing that ACGs from M. paniculata inhibit progression of ALI, we used the experimental model of lipopolysaccharide (LPS)-induced ALI in BALB/c mice to evaluate the therapeutic potential of purified ACGs. Our results showed that M. paniculata ACGs inhibited lung inflammation in animals undergoing ALI. The protective effects of ACGs were assessed by determination of cytokine levels and in situ analysis of lung inflammation. ACGs reduced the pulmonary edema and microvascular permeability, demonstrating a dose-dependent down-regulation of LPS-induced TNF-α, IL-6 and IL-1β expression in lung tissue and bronchoalveolar lavage fluid, along with reduced apoptosis. Moreover, metabolic profiling of mice serum and subsequent Ingenuity Pathway Analysis suggested that ACGs activated protective protein networks and pathways involving inflammatory regulators and apoptosis-related factors, such as JNK, ERK1/2 and caspase-3/7, suggesting that ACGs-dependent effects were related to MAPKs and mitochondrial apoptosis pathways. These results were further supported by evaluation of protein expression, showing that ACGs blocked LPS-activated phosphorylation of p38, ERK1/2 and JNK on the MAPKs signaling, and significantly upregulated the expression of Bcl-2 whilst down-regulated Bax and cleaved caspase-3. Remarkably, ACGs inhibited the LPS-dependent TLR4 and TRPC6 upregulation observed during ALI. Our study shows for the first time that ACGs inhibit acute inflammation and apoptosis by suppressing activation of TLR4/TRPC6 signaling pathway in a murine model of ALI. Our findings provide new evidence for better understanding the anti-inflammatory effects of ACGs. In this regard, ACGs could be exploited in the development of novel therapeutics for ALI and ARDS.

Thymol alleviates lipopolysaccharide-stimulated inflammatory response via downregulation of RhoA-mediated NF-κB signalling pathway in human peritoneal mesothelial cells

Thymol is one of the most important dietary constituents in the thyme species and has been shown to possess anti-inflammatory properties both in vivo and in vitro. We investigated the protective effects of thymol on the lipopolysaccharide (LPS)-induced inflammatory responses in the human peritoneal mesothelial cell line (HMrSV5) to clarify the potential mechanism. HMrSV5 cells were stimulated with LPS in the presence or absence of thymol. Our results showed that thymol markedly suppressed the production of cytokines such as tumour necrosis factor α (TNF-α), interleukin (IL)-6, monocyte chemoattractant protein 1 (MCP-1) and α-smooth muscle actin (α-SMA) in a dose-dependent manner. Western blot analysis indicated that RhoA and ROCK activation; Toll-like receptor 4 (TLR4) expression; and Nuclear factor -kappa B (NF-κB) p65, IKK and IκBα phosphorylation were also inhibited by thymol. Moreover, siRNA knockdown of RhoA suppressed the expression of pro-inflammatory cytokines and phosphorylation of NF-κB p65 and IκBα proteins in LPS-stimulated HMrSV5 cells, but did not affect TLR4 expression. In conclusion, thymol inhibits LPS-induced inflammation in HMrSV5 cells by suppressing TLR4-mediated RhoA-dependent NF-κB signalling pathway. Our study suggests that thymol may be a promising therapeutic agent against peritonitis.

Medicinal Plants of the Family Lamiaceae in Pain Therapy: A Review

Recently, numerous side effects of synthetic drugs have lead to using medicinal plants as a reliable source of new therapy. Pain is a global public health problem with a high impact on life quality and a huge economic implication, becoming one of the most important enemies in modern medicine. The medicinal use of plants as analgesic or antinociceptive drugs in traditional therapy is estimated to be about 80% of the world population. The Lamiaceae family, one of the most important herbal families, incorporates a wide variety of plants with biological and medical applications. In this study, the analgesic activity, possible active compounds of Lamiaceae genus, and also the possible mechanism of actions of these plants are presented. The data highlighted in this review paper provide valuable scientific information for the specific implications of Lamiaceae plants in pain modulation that might be used for isolation of potentially active compounds from some of these medicinal plants in future and formulation of commercial therapeutic agents.

Thymol attenuates the worsening of atopic dermatitis induced by Staphylococcus aureus membrane vesicles

Staphylococcus aureus membrane vesicles (MVs) aggravate atopic dermatitis (AD) through the delivery of bacterial effector molecules to host cells and the stimulation of inflammatory responses. This study investigated the inhibitory effect of thymol, a phenolic monoterpene found in essential oils derived from plants, on the worsening of AD induced by S. aureus MVs both in vitro and in vivo. The sub-minimal inhibitory concentrations of thymol disrupted S. aureus MVs. Intact S. aureus MVs induced the expression of pro-inflammatory cytokine (interleukin (IL)-1β, IL-6, and tumor necrosis factor-α) and chemokine (IL-8 and monocyte chemoattractant protein-1) genes in cultured keratinocytes, whereas thymol-treated S. aureus MVs did not stimulate the expression of these genes. Topical application of thymol-treated S. aureus MVs or treatment with thymol after intact S. aureus MVs to AD-like skin lesions diminished the pathology of AD. This included decreases in epidermal/dermal thickness and infiltration of eosinophils/mast cells, and inhibited expression of pro-inflammatory cytokine and chemokine genes in mouse AD model. Moreover, thymol significantly suppressed the Th1, Th2, and Th17-mediated inflammatory responses in AD-like skin lesions induced by S. aureus MVs, and reduced the serum levels of immunoglobulin (Ig) G2a, mite-specific IgE, and total IgE. In summary, thymol disrupts S. aureus MVs and suppresses inflammatory responses in AD-like skin lesions aggravated by S. aureus MVs. Our results suggest that thymol is a possible candidate for the management of AD aggravation induced by S. aureus colonization or infection in the lesions.