Chlorogenic acid protects mice against lipopolysaccharide-induced acute lung injury

Mechanism of Jizhi syrup's prevention and treatment of acute bronchitis based on LPS-iNOS inflammatory mediators' signalling

ETHNOPHARMACOLOGICAL RELEVANCE

Jizhi syrup (JZTJ) is composed of eight medicinal herbs, including Houttuynia cordata, Fagopyrum dibotrys, Ilex chinensis, Ephedra sinica, Aster tataricus, Peucedanum praeruptorum, Citrus aurantium and Glycyrrhiza uralensis. It is mainly used for coughing caused by exogenous wind heat. Symptoms include fever, aversion to cold, chest and diaphragm tightness, cough and sore throat; and acute bronchitis and acute exacerbation of chronic bronchitis with the above symptoms.

PURPOSE

This study aimed to preliminary analyse the chemical components in the liposoluble part of JZTJ, evaluate the anti-inflammatory effect of JZTJ by using six animal and cell models and predict the target and mechanism of acute bronchitis prevention and treatment with JZTJ.

METHODS

The chemical components in the liposoluble fraction of JZTJ (extracted by cyclohexane) were quantitatively analysed using gas chromatography-mass spectrometry (GC-MS). Classic non-specific inflammation models and acute bronchitis models were established to systematically evaluate the anti-inflammatory effect of JZTJ. The anti-inflammatory intensity and characteristics of three doses of JZTJ were comprehensively compared on the basis of principal component analysis method at the cellular and overall animal levels. By using lipopolysaccharides (LPSs) as modelling factors, a RAW264.7 macrophage inflammatory response model and a rat acute bronchitis model were created to study the effect of JZTJ on the in-vitro and - vivo LPS-iNOS-inflammatory mediators' inflammatory signalling pathway to reveal the mechanism of acute bronchitis prevention and treatment by JZTJ at the levels of genes, proteins, and inflammatory mediators.

RESULTS

Seventeen alkane and ester compounds were preliminarily qualitatively identified from the lipid soluble fraction of JZTJ: dibutyl phthalate, tetradecane, ridecane, n-hexadecanoic acid, pentadecane, n-decanoic acid, 2,6,10,14,18,22-tetracosahexaene, 2,6,10,15,19,23-hexamethyl-(all-E)-; phenol, 2,2'-methylenebis[6-(1,1-dimethylethyl)-4-methyl-; hexadecane. JZTJ has a significant inhibitory effect on acute non-specific inflammation, specifically inhibiting 'xylene-induced ear swelling in mice', 'acetic acid-induced increased permeability of abdominal capillaries in mice' and 'egg white-induced foot swelling in rats'. The above effects are most evident in high doses, followed by medium doses, whereas low doses have poorer or no effects. JZTJ can prevent and treat acute bronchitis induced by LPS in mice and rats, significantly improve the pathological changes in patchy interstitial and alveolar bleeding with excessive neutrophil infiltration and inhibit the release of inflammatory mediators by LPS-induced RAW264.7 macrophages. Its mechanism of action may be by downregulating the phosphorylation level of p-ERK1/2 protein, thereby inhibiting inducible nitric oxide synthase (iNOS) mRNA, tumour necrosis factor (TNF)-α mRNA and IL-1β. The expression levels of genes, such as mRNA and IL-6 mRNA, thereby reducing iNOS, TNF-α and IL-1β. The expression of proteins in the cytoplasm of lung and bronchial tissue cells reduced the release of downstream inflammatory mediators NO and IL-6.

CONCLUSION

Preliminary analysis of the chemical components in the lipid soluble fraction of JZTJ can lay the foundation for subsequent research on its effective components. Evaluating the anti-inflammatory effect of JZTJ is helpful for further research on its mechanism of action. The anti-inflammatory effects are exerted by regulating the inflammatory signalling pathway of LPS-iNOS inflammatory mediators, providing a scientific basis for their clinical application.

Evidence that a Novel Chalcone Derivative, Compound 27, Acts on the Epithelium Via the PI3K/AKT/Nrf2-Keap1 Signaling Pathway, to Mitigate LPS-Induced Acute Lung Injury in Mice

Acute lung injury (ALI) is a highly heterogeneous clinical syndrome and an important cause of mortality in critically ill patients, with limited treatment options currently available. Chalcone, an essential secondary metabolite found in edible or medicinal plants, exhibits good antioxidant activity and simple structure for easy synthesis. In our study, we synthesized a novel chalcone derivative, compound 27 (C27). We hypothesized that C27 could be a potential treatment for acute respiratory distress syndrome (ARDS). Therefore, the protective effects of C27 on lung epithelial cells during ALI and the underlying molecular mechanisms were investigated. In vivo, Intratracheal instillation of LPS (10 mg/kg) was used to induce acute lung injury in mice. In vitro, the bronchial epithelial cell line (Beas-2b) was treated with 30 μM tert-butyl hydroperoxide (t-BHP) to simulate oxidative stress. Our findings demonstrate that pretreatment with C27 reduces LPS-induced oxidative destruction and cellular apoptosis in lung tissues of mice. Furthermore, it significantly attenuates t-BHP-induced cellular reactive oxygen species (ROS) generation, mitochondrial damage, and apoptosis in vitro. Mechanistically, the signaling pathway involving Nrf2-Keap1 and the downstream antioxidative proteins were activated by C27 in vivo. Additionally, PI3K inhibitor LY294002 and Nrf2 inhibitor ML385 abolished the effect of C27 in vitro, indicating that the protective effect of C27 is mediated via the PI3K/AKT/Nrf2-Keap1 pathway. Our study provides evidence that C27 protects against LPS-induced ALI by mitigating oxidative stress via activation of the PI3K/AKT/Nrf2-Keap1 signaling pathway. Therefore, we hypothesize that C27 represents a viable alternative for ALI therapy.

Geniposidic acid alleviates osteoarthritis progression through inhibiting inflammation and chondrocytes ferroptosis

Osteoarthritis is one of the common diseases that seriously affects the quality of life of middle-aged and elderly people worldwide. Geniposidic acid (GPA) is extracted from Eucommia ulmoides that exhibits various pharmacological effects. This study investigated the function of GPA on osteoarthritis (OA) in IL-1β-stimulated mouse chondrocytes and mouse OA model. Mouse OA model was established by destabilization of the medial meniscus (DMM) and GPA was given intraperitoneal injection. The results demonstrated that GPA could alleviate DMM-induced OA in mice. In vitro, IL-1β-induced PGE2, NO, MMP1 and MMP3 were suppressed by GPA. Furthermore, IL-1β-induced ferroptosis was inhibited by GPA, as confirmed by the inhibition of MDA, iron, and ROS, as well as the upregulation of GSH, GPX4, and Ferritin. In addition, GPA was found to increase the expression of Nrf2 and HO-1. And the inhibition of GPA on IL-1β-induced inflammation and ferroptosis were prevented by Nrf2 inhibitor. In conclusion, GPA alleviates OA progression through inhibiting inflammation and chondrocytes ferroptosis via Nrf2 signalling pathway.

Chlorogenic Acid: A Systematic Review on the Biological Functions, Mechanistic Actions, and Therapeutic Potentials

Chlorogenic acid (CGA) is a type of polyphenol compound found in rich concentrations in many plants such as green coffee beans. As an active natural substance, CGA exerts diverse therapeutic effects in response to a variety of pathological challenges, particularly conditions associated with chronic metabolic diseases and age-related disorders. It shows multidimensional functions, including neuroprotection for neurodegenerative disorders and diabetic peripheral neuropathy, anti-inflammation, anti-oxidation, anti-pathogens, mitigation of cardiovascular disorders, skin diseases, diabetes mellitus, liver and kidney injuries, and anti-tumor activities. Mechanistically, its integrative functions act through the modulation of anti-inflammation/oxidation and metabolic homeostasis. It can thwart inflammatory constituents at multiple levels such as curtailing NF-kB pathways to neutralize primitive inflammatory factors, hindering inflammatory propagation, and alleviating inflammation-related tissue injury. It concurrently raises pivotal antioxidants by activating the Nrf2 pathway, thus scavenging excessive cellular free radicals. It elevates AMPK pathways for the maintenance and restoration of metabolic homeostasis of glucose and lipids. Additionally, CGA shows functions of neuromodulation by targeting neuroreceptors and ion channels. In this review, we systematically recapitulate CGA's pharmacological activities, medicinal properties, and mechanistic actions as a potential therapeutic agent. Further studies for defining its specific targeting molecules, improving its bioavailability, and validating its clinical efficacy are required to corroborate the therapeutic effects of CGA.

Traditional Tibetan medicine: therapeutic potential in lung diseases

Lung diseases have become a major threat to human health worldwide. Despite advances in treatment and intervention in recent years, effective drugs are still lacking for many lung diseases. As a traditional natural medicine, Tibetan medicine has had a long history of medicinal use in ethnic minority areas, and from ancient times to the present, it has a good effect on the treatment of lung diseases and has attracted more and more attention. In this review, a total of 586 Tibetan medicines were compiled through literature research of 25 classical works on Tibetan medicine, drug standards, and some Chinese and English databases. Among them, 33 Tibetan medicines have been studied to show their effectiveness in treating lung diseases. To investigate the uses of these Tibetan medicines in greater depth, we have reviewed the ethnomedicinal, phytochemical and pharmacological properties of the four commonly used Tibetan medicines for lung diseases (rhodiola, gentian, sea buckthorn, liexiang dujuan) and the five most frequently used Tibetan medicines (safflower, licorice, sandalwood, costus, myrobalan). It is expected to provide some reference for the development of new drugs of lung diseases in the future.

Illumination of Hydroxyl Radical in Kidney Injury and High-Throughput Screening of Natural Protectants Using a Fluorescent/Photoacoustic Probe

The hydroxyl radical (•OH) is shown to play a crucial role in the occurrence and progression of acute kidney injury (AKI). Therefore, the development of a robust •OH probe holds great promise for the early diagnosis of AKI, high-throughput screening (HTS) of natural protectants, and elucidating the molecular mechanism of intervention in AKI. Herein, the design and synthesis of an activatable fluorescent/photoacoustic (PA) probe (CDIA) for sensitive and selective imaging of •OH in AKI is reported. CDIA has near-infrared fluorescence/PA channels and fast activation kinetics, enabling the detection of the onset of •OH in an AKI model. The positive detection time of 12 h using this probe is superior to the 48-hour detection time for typical clinical assays, such as blood urea nitrogen and serum creatinine detection. Furthermore, a method is established using CDIA for HTS of natural •OH inhibitors from herbal medicines. Puerarin is screened out by activating the Sirt1/Nrf2/Keap1 signaling pathway to protect renal cells in AKI. Overall, this work provides a versatile and dual-mode tool for illuminating the •OH-related pathological process in AKI and screening additional compounds to prevent and treat AKI.

Modulation of MAPK/NF-κB Pathway and NLRP3 Inflammasome by Secondary Metabolites from Red Algae: A Mechanistic Study

The pharmacological properties of seaweeds are diverse. No studies have been conducted on the protective effect of Galaxaura oblongata (GOE) against lippopolysaccharide (LPS)-induced inflammation in the brain. This study is divided into three phases, the first of which is the initial phase. In vitro study includes antioxidant, radical scavenging, and anti-inflammatory activities, including cyclooxygenase-1 (COX1), COX2, NO, acetylcholine inhibition, sphingosine kinase 1, tumor necrosis factor α (TNF-α), and interleukin-6, as well as antioxidant and radical-scavenging activities, including 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azinobis(3-ethylbenzothiazoline)-6-sulfonic acid. Using LPS-induced acute inflammation, the second phase was conducted in vivo. Antioxidant and anti-inflammatory assays were performed to investigate the protective role of GOE. In addition to the phytochemical analysis, the bioactive content of GOE was also investigated. In vitro results demonstrated the potential of GOE as an antioxidant, anti-inflammatory, and neuroprotective agent. A study using LPS as an induced lung injury and neuroinflammation model confirmed the in vitro results. The GOE significantly reduced inflammatory, oxidative, and neurodegenerative biomarkers based on histopathological and immuno-histochemistry results. Based on computational drug design, four target proteins were approved: nuclear factor κB, mitogen-activated protein kinases, TNF-α, and NLRP3. Using polyphenolic compounds in GOE as ligands demonstrated good alignment and affinity against the three proteins. Finally, the current study offers a new approach to developing drug leads considering GOE's protective and curative roles.

Targeting TLR4/3 using chlorogenic acid ameliorates LPS+POLY I:C-induced acute respiratory distress syndrome via alleviating oxidative stress-mediated NLRP3/NF-κB axis

Acute lung injury (ALI) or acute respiratory distress syndrome (ARDS) is a life-threatening condition caused due to significant pulmonary and systemic inflammation. Chlorogenic acid (CGA) has been shown to possess potent antioxidant, anti-inflammatory, and immunoprotective properties. However, the protective effect of CGA on viral and bacterial-induced ALI/ARDS is not yet explored. Hence, the current study is aimed to evaluate the preclinical efficacy of CGA in lipopolysaccharide (LPS) and polyinosinic:polycytidylic acid (POLY I:C)-induced ALI/ARDS models in vitro and in vivo. Human airway epithelial (BEAS-2B) cells exposed to LPS+POLY I:C significantly elevated oxidative stress and inflammatory signaling. Co-treatment with CGA (10 and 50 µM) prevented inflammation and oxidative stress mediated by TLR4/TLR3 and NLRP3 inflammasome axis. BALB/c mice, when chronically challenged with LPS+POLY I:C showed a significant influx of immune cells, up-regulation of pro-inflammatory cytokines, namely: IL-6, IL-1β, and TNF-α, and treatment with intranasal CGA (1 and 5 mg/kg) normalized the elevated levels of immune cell infiltration as well as pro-inflammatory cytokines. D-Dimer, the serum marker for intravascular coagulation, was significantly increased in LPS+ POLY I:C challenged animals which was reduced with CGA treatment. Further, CGA treatment also has a beneficial effect on the lung and heart, as shown by improving lung physiological and cardiac functional parameters accompanied by the elevated antioxidant response and simultaneous reduction in tissue damage caused by LPS+POLY I:C co-infection. In summary, these comprehensive, in vitro and in vivo studies suggest that CGA may be a viable therapeutic option for bacterial and viral-induced ALI-ARDS-like pathology.

Effects of Herbs and Derived Natural Products on Lipopolysaccharide-Induced Toxicity: A Literature Review

Introduction

Oxidative stress (OS) during inflammation can increase inflammatory responses and damage tissue. Lipopolysaccharide (LPS) can induce oxidative stress and inflammation in several organs. Natural products have several biological activities including anti-inflammatory, antioxidant, and immunoregulatory properties. The aims of the study are to study the possible therapeutic effects of natural products on LPS inducing toxicity on the nervous system, lung, liver, and immune system.

Methods

The in vitro and in vivo research articles that were published in the last 5 years were included in the current study. The keywords included "lipopolysaccharide," "toxicity," "natural products," and "plant extract" were searched in different databases such as Scopus, PubMed, and Google Scholar until October 2021.

Results

The results of most studies indicated that some medicinal herbs and their potent natural products can help to prevent, treat, and manage LPS-induced toxicity. Medicinal herbs and plant-derived natural products showed promising effects on managing and treating oxidative stress, inflammation, and immunomodulation by several mechanisms.

Conclusion

However, these findings provide information about natural products for the prevention and treatment of LPS-induced toxicity, but the scientific validation of natural products requires more evidence on animal models to replace modern commercial medicine.

Integrated Proteomics and Metabolomics Analysis to Explore the Amelioration Mechanisms of Rosa roxburghii Tratt Fruit Polyphenols on Lipopolysaccharide-Induced Acute Lung Injury Mice

Acute lung injury (ALI) is the main cause of death for the elderly and children due to its high morbidity and mortality rates. Plant-derived functional foods are becoming increasingly important to the healthcare and food industries for adjunctive and alternative treatments of ALI. Polyphenols have been regarded to be beneficial to the prevention and amelioration of ALI. Rosa roxburghii Tratt fruit polyphenols (RRTP) has potential to prevent ALI, but mechanism remains unclear. This study was set up to systematically analyze the RRTP extract active ingredients, comprehensively evaluate its protective effects via lung histopathological examination, protein concentration, and cytokines production in ALI mice induced by lipopolysaccharide (LPS), and finally revealed alleviation mechanisms of the regulatory effects of RRTP by proteomics and metabolomics approach. The results demonstrated RRTP could synergistically exert significant preventive effects against ALI by notably ameliorating lung histopathological damage and pulmonary capillary permeability in ALI mice, inhibiting lung tissue inflammatory response and acute phase proteins and S-100 calcium binding proteins, suppressing excessive activation of complement and coagulation cascades, and regulating disordered lipids metabolism and amino acid metabolism. This study illustrated that RRTP has obvious advantages in ALI adjunctive therapy and revealed the complicated amelioration mechanisms, which provides a breakthrough for the development and demonstration of RRTP as a nutritional compound additive for complementary therapy of ALI.

Sichen Formula Ameliorates Lipopolysaccharide-Induced Acute Lung Injury via Blocking the TLR4 Signaling Pathways

Purpose

Sichen (SC) formula is a classic prescription of Tibetan medicine. Due to its potential anti-inflammatory effect, the SC formula has been clinically used to treat respiratory diseases for many years in the Chinese Tibet region. The present study aimed to investigate the anti-inflammatory effect of SC and explore the underlying mechanisms.

Methods

SC formula was characterized by HPLC analysis. The acute lung injury (ALI) mouse model was induced by direct intratracheal lipopolysaccharide (LPS) instillation, and bronchoalveolar lavage fluid (BALF) and lung tissues were collected. Meanwhile, RAW264.7 macrophages were stimulated by LPS. The contents of inflammatory mediators in the culture medium were determined by ELISA. Protein levels were determined by immunohistochemical staining or Western blotting. Nuclear localization of NF-κB, AP-1, and IRF3 was performed using immunofluorescence and Western blotting.

Results

In the LPS-induced ALI mouse model, SC treatment suppressed the secretion of inflammatory mediators (TNF-α, IL-6, IL-1β, MCP-1, MIP-1α, and RANTES) in BALF. SC treatment hindered the recruitment of macrophages. SC treatment also inhibited the expression of CD68, p-p65, and TLR4 in the lung tissue. In the LPS-exposed RAW264.7 cells, the cell viability was not changed up to 400 μg/mL of SC. SC concentration-dependently suppressed the production of nitric oxide, prostaglandin E2, TNF-α, IL-6, MCP-1, MIP-1α, and RANTES in LPS-challenged RAW264.7 cells. The expression levels of iNOS, COX-2, p-p38, p-JNK, p-ERK, p-TBK1, p-IKKα/β, p-IκB, p-p65, p-c-Jun, and p-IRF3 were decreased after SC treatment. Moreover, the nuclear translocation of p65, c-Jun, and IRF3 was also blocked by SC treatment.

Conclusion

SC treatment inhibited the inflammatory responses in LPS-induced ALI mouse model/RAW264.7 macrophages. The underlying mechanism of this action may be closely associated with the suppression of TLR4 signaling pathways. These research findings provide further pharmacological justifications for the medicinal use of SC in the management of respiratory diseases.

Systematic characterization of components of Makyo-kanseki-to granule and serum metabolomics for exploring its protective mechanism against acute lung injury in lipopolysaccharide-induced rats

Makyo-kanseki-to has been used for the treatment of pneumonia, becoming a basic formula for coronavirus disease 2019. However, the chemical profile of Makyo-kanseki-to granule and its possible mechanism against acute lung injury from terminal metabolic regulation have been unclear. The aim of this study was to characterize the constituents in Makyo-kanseki-to granule and reveal the potential related mechanism of Makyo-kanseki-to granule treatment for acute lung injury using a rat model of lipopolysaccharide-induced acute lung injury. Totally, 78 constituents were characterized based on ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. Makyo-kanseki-to granule could alleviate acute lung injury through modulating rectal temperature, pulmonary edema, histopathology, and processes of inflammatory and oxidative stress. Twenty-two potential biomarkers in acute lung injury rats were identified by metabolomics based on ultra-performance liquid chromatography coupled with quadrupole exactive high-field mass spectrometry. They were mainly involved in amino acids and glycerophospholipid metabolism, which were regulated by Makyo-kanseki-to granule. The present results not only increase the understanding of the chemical profile and molecular mechanism of Makyo-kanseki-to granule mediated protection against acute lung injury but also provide an experimental basis and new ideas for further development and clinical application of Makyo-kanseki-to granule.

Optimization of Glycerol Extraction of Chlorogenic Acid from Honeysuckle by Response Surface Methodology

Using honeysuckle as raw material, chlorogenic acid (CGA) was extracted with different alcohols. Based on the single-factor experiment design, the relationship between each parameter and the response value was explored by Box–Behnken method to optimize the process conditions. Best extraction results were obtained under the conditions of solid-to-liquid ratio of 1:20, the ultrasonic time of 40 min, the ultrasonic vibrator power of 240 w, and the CGA extraction rate of 2.98%. The experimental data show that the extraction rate of CGA is related to the length of the alcohol carbon chain and the number of hydroxyl groups in the extractant. The results from this work can provide technical basis for the safe and efficient production of CGA from honeysuckle.

Chlorogenic acid enhances alveolar macrophages phagocytosis in acute respiratory distress syndrome by activating G protein-coupled receptor 37 (GPR 37)

BACKGROUND

Impaired alveolar macrophages phagocytosis can contribute to pathogenesis of acute respiratory distress syndrome (ARDS) and negatively impacts clinical outcomes. Chlorogenic acid (CGA) is a naturally occurring polyphenolic compound with potential anti-inflammatory and antioxidant bioactivities. Studies have shown that CGA plays a protective role in ARDS, however, the precise protective mechanism of CGA against ARDS, is still unclear.

PURPOSE

The aim of this study was to investigate whether CGA enhances alveolar macrophages phagocytosis to attenuate lung injury during ARDS.

METHODS

RAW264.7 cells were stimulated with lipopolysaccharides (100 μg/ml for 24 h) and treated with CGA (100, 200, and 400 μM CGA for 1 h) to measure pro-inflammatory cytokine levels, GPR37 expression and macrophages phagocytosis. Mouse models of ARDS induced by cecal ligation and perforation (CLP) surgery were treated with CGA (100 or 200 mg/kg) to investigate lung inflammatory injury and alveolar macrophages phagocytosis. Computational modeling was performed to examine potential binding sites of G protein-coupled receptor 37 (GPR37) with CGA, and the results were validated by interfering with the binding sites.

RESULT

In vitro, CGA notably ameliorated inflammatory response and increased phagocytosis in lipopolysaccharides-induced RAW264.7 cells. In vivo, CGA administration significantly alleviated lung inflammatory injury, decreased the bacteria load in the lung, promoted alveolar macrophages phagocytosis and improved the survival rate in mice with CLP-induced ARDS. Moreover, CGA markedly upregulated the expression of GPR37 in vivo and in vitro. However, the protective effect of CGA against ARDS were reversed after silencing the expression of GPR37.

CONCLUSION

CGA has a protective effect against ARDS and may enhance alveolar macrophages phagocytosis and attenuate lung inflammatory injury by upregulating GPR37 expression.

Combination therapy with budesonide and N-acetylcysteine ameliorates LPS-induced ALI by attenuating neutrophil recruitment through the miR-196b-5p/Socs3 molecular axis

Background

Neutrophil infiltration accelerates the inflammatory response and is highly correlated to the development of acute lung injury (ALI). Budesonide (BUD) and N-acetylcysteine (NAC) both inhibit the inflammatory response to alleviate ALI, so we further investigated whether their combination is better for ALI.

Methods

In this study, we investigated the effect and mechanism of Combined BUD and NAC therapy on LPS-induced ALI. Rat ALI model and neutrophil abnormal activation model were established by lipopolysaccharide (LPS). BUD and NAC were treated alone or in combination, or cells were transfected with miR-196b-5p mimic or si-Socs3 to evaluate the efficacy and mechanism of BUD and NAC alone or in combination. Histopathological observation of lungs was performed by Hematoxylin Eosin (HE) staining. The quantity of neutrophils and inflammatory factors level in bronchoalveolar lavage fluid (BALF) were determined by Richter-Gimza complex stain and Enzyme-Linked Immunosorbnent Assay (ELISA), respectively. ReverseTranscription-PolymeraseChainReaction (RT–qPCR) was utilized to assess miR-196b-5p and inflammatory factor mRNA levels. The expression level of Socs3 was detected by immunohistochemistry or Western Blot.

Results

BUD and NAC combined treatment had a better effect on neutrophil recruitment and inflammatory response in LPS-induced ALI than did BUD and NAC alone. Transfection of the miR-196b-5p mimic reversed the effect of combined BUD and NAC. In conclusion, the combination of BUD and NAC is a better treatment for ALI.

Conclusions

Combination therapy with BUD and NAC ameliorates LPS-induced ALI by attenuating neutrophil recruitment through the miR-196b-5p/Socs3 molecular axis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-02185-7.

A review of the protective effects of chlorogenic acid against different chemicals

Chlorogenic acid (CGA) is a naturally occurring non-flavonoid polyphenol found in green coffee beans, teas, certain fruits, and vegetables, that exerts antiviral, antitumor, antibacterial, and antioxidant effects. Several in vivo and in vitro studies have demonstrated that CGA can protect against toxicities induced by chemicals of different classes such as fungal/bacterial toxins, pharmaceuticals, metals, pesticides, etc., by preservation of cell survival via reducing overproduction of nitric oxide and reactive oxygen species and suppressed pro-apoptotic signaling. CGA antioxidant effects mediated through the Nrf2-heme oxygenase-1 signaling pathway were shown to enhance the levels of antioxidant enzymes such as superoxide dismutase, catalase, glutathione-S-transferases, glutathione peroxidase, and glutathione reductase as well as glutathione content. Also, CGA could suppress inflammation via inhibition of toll-like receptor 4 and MyD88, and the phosphorylation of inhibitor of kappa B and p65 subunit of NF-κB, resulting in diminished levels of downstream inflammatory factors including interleukin (IL)-1 β, IL-6, tumor necrosis factor-α, macrophage inflammatory protein 2, cyclooxygenase-2, and prostaglandin E2. Moreover, CGA inhibited apoptosis by reducing Bax, cytochrome C, and caspase 3 and 9 expression while increasing Bcl-2 levels. The present review discusses several mechanisms through which CGA may exert its protective role against such agents. Chemical and natural toxic agents affect human health. Phenolic antioxidant compounds can suppress free radical production and combat these toxins. Chlorogenic acid is a plant polyphenol present in the human diet and exerts strong antioxidant properties that can effectively help in the treatment of various toxicities.

A Medicinal Halophyte Ipomoea pes-caprae (Linn.) R. Br.: A Review of Its Botany, Traditional Uses, Phytochemistry, and Bioactivity

Ipomoea pes-caprae (Linn.) R. Br. (Convolvulaceae) is a halophytic plant that favorably grows in tropical and subtropical countries in Asia, America, Africa, and Australia. Even though this plant is considered a pan-tropical plant, I. pes-caprae has been found to occur in inland habitats and coasts of wider areas, such as Spain, Anguilla, South Africa, and Marshall Island, either through a purposeful introduction, accidentally by dispersal, or by spreading due to climate change. The plant parts are used in traditional medicine for treating a wide range of diseases, such as inflammation, gastrointestinal disorders, pain, and hypertension. Previous phytochemical analyses of the plant have revealed pharmacologically active components, such as alkaloids, glycosides, steroids, terpenoids, and flavonoids. These phytoconstituents are responsible for the wide range of biological activities possessed by I. pes-caprae plant parts and extracts. This review arranges the previous reports on the botany, distribution, traditional uses, chemical constituents, and biological activities of I. pes-caprae to facilitate further studies that would lead to the discovery of novel bioactive natural products from this halophyte.

Artemisia gmelinii Attenuates Lung Inflammation by Suppressing the NF-κB/MAPK Pathway

Cigarette smoke (CS) is the main cause of chronic obstructive pulmonary disease (COPD), and continuous CS exposure causes lung inflammation and deterioration. To investigate the protective effects of Artemisia gmelinii against lung inflammation in this study, cigarette smoke extract (CSE)/lipopolysaccharide (LPS)-treated alveolar macrophages (AMs) and mice stimulated with CSE/porcine pancreas elastase (PPE) were used. Artemisia gmelinii ethanol extract (AGE) was effective in decreasing the levels of cytokines, chemokine, inducible nitric oxide synthase, and cyclooxygenase-2 by inhibiting mitogen-activated protein (MAP) kinases/nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathway in AMs. Additionally, oral administration of AGE suppressed inflammatory cells’ infiltration and secretion of inflammatory cytokines, chemokines, matrix metallopeptidase 9, and neutrophil extracellular traps in bronchoalveolar lavage fluid from the COPD model. Moreover, the obstruction of small airways, the destruction of the lung parenchyma, and expression of IL-6, TNF-α, IL-1β, and MIP-2 were suppressed by inhibiting NF-κB activation in the lung tissues of the AGE group. These effects are associated with scopolin, chlorogenic acid, hyperoside, 3,4-di-O-caffeoylquinic acid, 3,5-di-O-caffeoylquinic acid, and 4,5-di-O-caffeoylquinic acid, which are the main components of AGE. These data demonstrate the mitigation effect of AGE on lung inflammation via inhibition of MAPK and NF-κB pathways, suggesting that AGE may be instrumental in improving respiratory and lung health.

Coffea arabica extracts and their chemical constituents in a murine model of gouty arthritis: How they modulate pain and inflammation

ETHNOPHARMACOLOGICAL RELEVANCE

Coffea arabica is commonly known for its cardiotonic and neurotonic activities, but in some places' folk medicine, like in Arabia and Africa, C. arabica is used to treat headache, migraine, the flu, anemia, oedema, asthenia, asthma, inflammation and wounds.

AIMS OF THE STUDY

The aims were to evaluate if the aqueous extracts of Coffea arabica, prepared from beans with different degrees of roasting, and their main chemical constituents could exert an in vivo anti-gouty effect.

MATERIALS AND METHODS

Coffea extracts were obtained from the beans of not roasted, light, medium and dark roasted coffee and from decaffeinated and traditional coffees and were prepared with water at 25°C and at 98°C. C57BL/6 mice were induced to gout by an injection of monosodium urate crystals and treated with coffee extracts at doses of 25, 75 and 225 mg/kg and their chemical constituents at a dose of 10 mg/kg. The antinociceptive and anti-inflammatory effects were evaluated.

RESULTS

Treatments with Coffea extracts prepared with water at 98°C were more effective to exert antinociceptive and anti-inflammatory activities than the ones prepared with water at 25°C. Caffeic and chlorogenic acids reduced hypernociception in animals when compared with negative control group (7.79 and 5.69 vs 18.53; P < 0.05 and P < 0.001, respectively), inhibited neutrophil migration (1.59 × 104 and 0.38 × 104 vs 9.47 × 104; P < 0.0001 both) and decreased pro-inflammatory cytokines concentration (IL-1β, IL-6 and TNF-α).

CONCLUSIONS

We have demonstrated that our treatments attenuated gout, and this effect could be attributed to a reducement in hypernociception, neutrophil migration and cytokines concentration. These results suggest coffee as a potential candidate for studies in acute gout therapy.

Ginger and 6-gingerol prevent lipopolysaccharide-induced intestinal barrier damage and liver injury in mice

BACKGROUND

Inflammation-related diseases present a significant public health problem. Ginger is a flavoring spice and medicinal herb with anti-inflammatory activity. This study investigated the preventive effects of ginger extract (GE) and its main bioactive component, 6-gingerol (6G), on lipopolysaccharide (LPS)-induced intestinal barrier dysfunction and liver injury in mice.

RESULTS

GE and 6G were orally administered to mice for seven consecutive days before LPS administration. After 24 h, the mice were sacrificed. GE and 6G were found to significantly reverse LPS-induced inflammation in the mouse ileum by modifying the NF-κB pathway. They also alleviated apoptosis in the ileum by downregulating Bax and cytochrome c gene expression and by inhibiting the caspase-3 pathway. Through the aforementioned mechanisms, GE and 6G restored the intestinal barrier by increasing ZO-1 and claudin-1 protein expressions. Gut-derived LPS induced inflammation and apoptosis in the liver; these effects were markedly reversed through GE and 6G treatment. 6G was the most abundant component in GE, as evidenced through liquid chromatography-mass spectrometry, and accounted for >50% of total gingerols and shogaols in GE.

CONCLUSION

The current results support the use of GE and 6G as dietary supplements to protect against gut-derived endotoxemia-associated inflammatory response and disorders. © 2021 Society of Chemical Industry.

Qingwenzhike Prescription Alleviates Acute Lung Injury Induced by LPS via Inhibiting TLR4/NF-kB Pathway and NLRP3 Inflammasome Activation

Background: Acute lung injury (ALI) is characterized by dysfunction of the alveolar epithelial membrane caused by acute inflammation and tissue injury. Qingwenzhike (QWZK) prescription has been demonstrated to be effective against respiratory viral infections in clinical practices, including coronavirus disease 2019 (COVID-19) infection. So far, the chemical compositions, protective effects on ALI, and possible anti-inflammatory mechanisms remain unknown.

Methods: In this study, the compositions of QWZK were determined via the linear ion trap/electrostatic field orbital trap tandem high-resolution mass spectrometry (UHPLC-LTQ-Orbitrap MS). To test the protective effects of QWZK on ALI, an ALI model induced by lipopolysaccharide (LPS) in rats was used. The effects of QWZK on the LPS-induced ALI were evaluated by pathological changes and the number and classification of white blood cell (WBC) in bronchoalveolar lavage fluid (BALF). To investigate the possible underlying mechanisms, the contents of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein (MCP-1), interleukin-1β (IL-1β), interleukin-18 (IL-18), and immunoregulatory-related factors interferon-γ (IFN-γ) were detected by ELISA. Furthermore, the expression of Toll-like receptor 4 (TLR4), p-IKKα/β, IKKα, IKKβ, p-IκBα, IκBα, p-NF-κB, nuclear factor-κB (NF-κB), NOD-like receptor family pyrin domain containing 3 (NLRP3), cleaved caspase-1, pro-caspase-1, apoptosis-associated speck-like protein containing CARD (ASC), and β-actin were tested by Western blot.

Results: A total of 99 compounds were identified in QWZK, including 33 flavonoids, 23 phenolic acids, 3 alkaloids, 3 coumarins, 20 triterpenoids, 5 anthraquinones, and 12 others. ALI rats induced by LPS exhibited significant increase in neutrophile, significant decrease in lymphocyte, and evidently thicker alveolar wall than control animals. QWZK reversed the changes in WBC count and alveolar wall to normal level on the model of ALI induced by LPS. ELISA results revealed that QWZK significantly reduced the overexpression of proinflammatory factors IL-6, TNF-α, MCP-1, IL-1β, IL-18, and IFN-γ induced by LPS. Western blot results demonstrated that QWZK significantly downregulated the overexpression of TLR4, p-IKKα/β, p-IκBα, p-NF-κB, NLRP3, cleaved caspase-1, and ASC induced by LPS, which suggested that QWZK inhibited TLR4/NF-κB signaling pathway and NLRP3 inflammasomes.

Conclusions: The chemical compositions of QWZK were first identified. It was demonstrated that QWZK showed protective effects on ALI induced by LPS. The possible underlying mechanisms of QWZK on ALI induced by LPS was via inhibiting TLR4/NF-kB signaling pathway and NLRP3 inflammasome activation. This work suggested that QWZK is a potential therapeutic candidate for the treatments of ALI and pulmonary inflammation.

Glutamine Supplementation Attenuates the Inflammation Caused by LPS-Induced Acute Lung Injury in Mice by Regulating the TLR4/MAPK Signaling Pathway

Bacterial infection is one of the main causes of bovine respiratory disease (BRD), which can cause tremendous losses for the herd farming industry worldwide. L-Glutamine (GLN), a neutral amino acid, has been reported to have anti-inflammatory properties. This study aims to explore the potential protective effects and mechanisms of GLN on acute lung injury (ALI) induced by lipopolysaccharide (LPS) in mice. Forty ICR mice were randomly divided into four groups (n = 10): a PBS intratracheal instillation group, a LPS intratracheal instillation group, a GLN gavage group, and a LPS+GLN group (GLN was given 1 h before the LPS stimulation). Twelve hours after LPS administration, the lung tissue and blood were collected. The results showed that the concentrations of IL-6, IL-8, and IL-1β; the protein abundance of the toll-like receptor 4 (TLR4), phosphorylated p38 (p-p38), phosphorylated ERK1/2 (p-ERK1/2), and phosphorylated JNK (p-JNK); and the expression level of genes associated with inflammation, such as IL-1β, IL-8, TNF-α, IL-6, TLR4, p38, ERK1/2, and JNK, were significantly increased in the LPS group compared with those in the PBS group. However, these increases were attenuated by GLN pretreatment in the LPS+GLN group. Furthermore, the pathological change of the structure of lung tissue from the LPS group was obvious compared to that from the PBS group; however, with GLN administration, these pathological changes were alleviated. Additionally, the secretion level of mucus and the percentage of positive MUC5AC staining on the epithelial surface area of the airway increased dramatically in the LPS group; however, GLN pretreatment in the LPS+GLN group markedly decreased these phenomena compared with that of the LPS group. These results indicate that GLN supplementation ameliorates LPS-induced ALI in mice and this effect may be mediated by the TLR4/MAPK signaling pathway.

Inhibitory Effect of Chlorogenic Acid Analogues Comprising Pyridine and Pyrimidine on α-MSH-Stimulated Melanogenesis and Stability of Acyl Analogues in Methanol

In continuation of studies for α-MSH stimulated melanogenesis inhibitors, we have evaluated the design, synthesis, and activity of a new series of chlorogenic acid (CGA) analogues comprising pyridine, pyrimidine, and diacyl derivatives. Among nineteen synthesized compounds, most of them (fifteen) exhibited better inhibitions of melanin formation in B16 melanoma cells. The results illustrated that a pyridine analogue 6f and a diacyl derivative 13a of CGA showed superior inhibition profiles (IC50: 2.5 ± 0.7 μM and 1.1 ± 0.1 μM, respectively) of α-MSH activities than positive controls, kojic acid and arbutin (IC50: 54 ± 1.5 μM and 380 ± 9.5 μM, respectively). The SAR studies showed that both -CF3 and -Cl groups exhibited better inhibition at the meta position on benzylamine than their ortho and para positions. In addition, the stability of diacyl analogues of CGA in methanol monitored by HPLC for 28 days indicated the steric bulkiness of acyl substituents as a key factor in their stability.

Antiviral effect of fufang yinhua jiedu (FFYH) granules against influenza A virus through regulating the inflammatory responses by TLR7/MyD88 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Fufang-Yinhua-Jiedu Granules (FFYH) optimized from a Yin-Qiao-San, as traditional Chinese medicine (TCM), was used to treat influenza and upper respiratory tract infection and was recommended for the prevention and treatment of SARS in 2003 and current COVID-19 in Anhui Province in 2020.

AIM OF STUDY

In the clinical studies, FFYH was very effective for the treatment of influenza, but the mechanism of action against influenza A virus remains unclear. In the present study, we investigated the antiviral effect of FFYH against influenza A virus in vitro and vivo. Moreover, the potential mechanism of FFYH against influenza A virus in vivo was investigated for the first time.

MATERIALS AND METHODS

CPE inhibition assay and HA assay were used to evaluate the in vitro antiviral effects of FFYH against influenza A virus H1N1, H3N2, H5N1, H7N9 and H9N2. Mice were used to evaluate the antiviral effect of FFYH in vivo with ribavirin and lianhuaqingwen as positive controls. RT-PCR was used to quantify the mRNA transcription of TNF-α, IL-6, IFN-γ, IP10, and IL-1β mRNA. ELISA was used to examine the expression of inflammatory factors such as TNF-α, IL-6, IFN-γ, IP10, and IL-1β in sera. The blood parameters were analyzed with auto hematology analyzer. Moreover, the potential mechanism of FFYH against influenza A virus in vivo was also investigated.

RESULTS

FFYH showed a broad-spectrum of antiviral activity against H1N1, H3N2, H5N1, H7N9, and H9N2 influenza A viruses. Furthermore, FFYH dose-dependently increased the survival rate, significantly prolonged the median survival time of mice, and markedly reduced lung injury caused by influenza A virus. Also, FFYH significantly improve the sick signs, food taken, weight loss, blood parameters, lung index, and lung pathological changes. Moreover, FFYH could markedly inhibit the inflammatory cytokine expression of TNF-α, IL-6, IFN-γ, IP10, IL-10, and IL-1β mRNA or protein via inhibition of the TLR7/MyD88/NF-κB signaling pathway in vivo.

CONCLUSION

FFYH not only showed a broad-spectrum of anti-influenza virus activity in vitro, but also exhibited a significant protective effect against lethal influenza virus infection in vivo. Furthermore, our results indicated that the in vivo antiviral effect of FFYH against influenza virus may be attributed to suppressing the expression of inflammatory cytokines via regulating the TLR7/MyD88/NF-κB signaling pathway. These findings provide evidence for the clinical treatment of influenza A virus infection with FFYH.

Simvastatin attenuates acute lung injury by activation of A2B adenosine receptor

To explore the protective mechanism of simvastatin in acute lung injury (ALI), the lipopolysaccharide (LPS) induced (5 mg/kg) ALI rat model was used to examine the effects of simvastatin. Following simvastatin treatment, the histopathological evaluation of lung tissues was made using hematoxylin and eosin (H&E) staining. Also, myeloperoxidase (MPO) activity and the levels of tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), and IL-10 were determined by ELISA. Blood gas analyses of arterial blood samples were performed to assess the pulmonary gas exchange. Moreover, the neutrophil count and total protein content were determined in the bronchoalveolar lavage (BAL) fluid. The ratio of wet lung to dry lung (W/D) and the alveolar fluid clearance (AFC) were calculated to estimate the severity of edema. Lastly, the levels of A2BAR, CFTR, claudin4, and claudin18 were also measured by qRT-PCR and Western blotting. Simvastatin treatment, in a dose-related manner, markedly improved the lung histological injury and decreased the levels of TNF-α, IL-1β, and increased IL-10 in LPS induced ALI. Also, pulmonary neutrophil count was alleviated. Besides, a decreased ratio of W/D lung also confirmed the simvastatin intervention. Notably, simvastatin reduced the levels of A2BAR, CFTR, and claudin18 but upregulated claudin4 in lung tissues. Additionally, treatment with PSB1115, an antagonist of A2BAR, countered the protective effect of simvastatin in ALI. Our study demonstrates that simvastatin has a protective effect against LPS-induced ALI by activating A2BAR and should be exploited as a novel therapeutic target for the treatment of ALI.

Neuroprotective effects of Levisticum officinale on LPS-induced spatial learning and memory impairments through neurotrophic, anti-inflammatory, and antioxidant properties

Levisticum officinale (Apiaceae) has been identified as a medicinal plant in traditional medicine, with the anti-inflammatory, antioxidant, and anticholinesterase activities. The present study aims to evaluate the effects of Levisticum officinale extract (LOE) on lipopolysaccharide (LPS)-induced learning and memory deficits and to examine its potential mechanisms. LOE was administered to adult male Wistar rats at doses of 100, 200, and 400 mg kg-1 for a week. Later, LPS was intraperitoneally injected at a dose of 1 mg kg-1 to induce neuroinflammation, and treatment with LOE continued for 3 more weeks. Behavioral, biochemical, and molecular analyses were performed at the end of the experiment. Moreover, quantitative immunohistochemical assessments of the expression of Ki-67 (intracellular proliferation marker) in the hippocampus were performed. The results revealed that LPS injection caused spatial memory impairment in the rats. Daily LOE treatment at applied doses for 4 weeks attenuated spatial learning and memory deficits in LPS-injected rats. Furthermore, LPS significantly increased the mRNA expression level of interleukin-6 in the hippocampus, which was accompanied by decreased brain-derived neurotrophic factor (BDNF) mRNA expression levels. Moreover, LPS increased the levels of malondialdehyde, reduced the antioxidant enzyme activities of catalase and superoxide dismutase in the hippocampus, and impaired neurogenesis. However, pre-treatment with LOE at a dose of 100 mg kg-1 significantly reversed the LPS-induced changes, and improved neurogenesis. In conclusion, the beneficial effect of LOE on the improvement of learning and memory could be attributed to its anti-inflammatory and antioxidant activities, along with its ability to increase BDNF expression and neurogenesis in the hippocampus.

NMR-Based Metabolomic Analyses to Identify the Effect of Harvesting Frequencies on the Leaf Metabolite Profile of a Moringa oleifera Cultivar Grown in an Open Hydroponic System

Moringa oleifera Lam. is one of the world’s most useful medicinal plants. Different parts of the M. oleifera tree contain a rich profile of important minerals, proteins, vitamins, and various important bioactive compounds. However, there are differences in the phytochemical composition of the medicinal plant’s raw materials due to seasonal variation, cultivation practices, and post-harvest processing. The main objective of this study was therefore to determine the effect of harvesting frequencies on selected bioactive compounds of a M. oleifera cultivar (PKM1) grown in a hydroponic system under a shade net structure. Three harvesting frequency treatments were applied in the study, with the plants harvested at every 30 days (high frequency), 60 days (intermediate frequency), and 90 days (low frequency) respectively. ¹H-NMR was used for data acquisition, and multivariate data analysis by means of principal component analysis (PCA), partial least square discriminatory analysis (PLS-DA), and orthogonal partial least square discriminatory analysis (OPLS-DA) were applied to determine the changes in the leaf metabolite profile, and also to identify the spectral features contributing to the separation of samples. Targeted metabolite analysis was used to match the NMR peaks of the compounds with the NMR chemical shifts of the contribution plot. The contribution plot showed that the increase in concentration of some compounds in aliphatic, sugar and aromatic regions contributed to the separation of the samples. The results revealed that intermediate and low harvesting frequencies resulted in a change in the leaf metabolite profile. Compounds such as chlorogenic acid, ferulic acid, vanillic acid, wogonin, esculetin, niazirin, and gamma-aminobutyric acid (GABA) showed an increase under intermediate and low harvesting frequencies. These results provide insight into the effect of harvesting frequencies on the metabolite profile and associated medicinal activity of M. oleifera.

Acidic preconditioning reduces lipopolysaccharide-induced acute lung injury by upregulating the expression of angiotensin-converting enzyme 2

Acid preconditioning (APC) through carbon dioxide inhalation can exert protective effects during acute lung injury (ALI) triggered by ischemia-reperfusion. Angiotensin-converting enzyme 2 (ACE2) has been identified as a receptor for severe acute respiratory syndrome coronavirus and the novel coronavirus disease-19. Downregulation of ACE2 plays an important role in the pathogenesis of severe lung failure after viral or bacterial infections. The aim of the present study was to examine the anti-inflammatory mechanism through which APC alleviates lipopolysaccharide (LPS)-induced ALI in vivo and in vitro. The present results demonstrated that LPS significantly downregulated the expression of ACE2, while APC significantly reduced LPS-induced ALI and provided beneficial effects. In addition, bioinformatics analysis indicated that microRNA (miR)-200c-3p directly targeted the 3'untranslated region of ACE2 and regulated the expression of ACE2 protein. LPS exposure inhibited the expression of ACE2 protein in A549 cells by upregulating the levels of miR-200c-3p. However, APC inhibited the upregulation of miR-200c-3p induced by LPS, as well as the downregulation of ACE2 protein, through the NF-κB pathway. In conclusion, although LPS can inhibit the expression of ACE2 by upregulating the levels of miR-200c-3p through the NF-κB pathway, APC inhibited this effect, thus reducing inflammation during LPS-induced ALI.

A synthetic chalcone derivative, compound 39, alleviates lipopolysaccharide-induced acute lung injury in mice

Our research group has previously synthesized various chalcone analogues. Of these analogues, compound 39 has been shown to exhibit potent antioxidative activities but its anti-inflammatory and anti-apoptosis effects remain unclear. Thus, the present study investigated the in vivo and in vitro effects and mechanisms of compound 39 in lipopolysaccharide (LPS)-induced acute lung injury (ALI). To induce ALI, the mice received LPS via a tracheal instillation 6 h after intragastric administration of compound 39 or vehicle. Histological changes, the lung wet/dry weight ratio, and the amounts of protein and inflammatory cells in the broncho-alveolar lavage (BAL) fluid were assessed after 24 h. Additionally, to determine its underlying mechanisms, Western blot and immunofluorescence analyses were used. Moreover, the in vitro effects of compound 39 were also investigated. In the in vivo experiment, compound 39 markedly alleviated histopathological alterations, lung edema, and protein leakage, and exhibited potent anti-inflammatory effects. In the in vitro experiments, compound 39 dose-dependently reduced the levels of pro-inflammatory cytokines and reactive oxygen species. The results suggested that the anti-inflammatory effects of compound 39 were due to suppression of the mitogen-activated protein kinase (MAPK)/nuclear factor κB (NF-κB) pathway. Compound 39 also enhanced the protein levels of Bcl-2 and reduced the protein levels of Bax and cleaved caspase-3. The present study confirmed the anti-inflammatory, oxy-radical prohibitive, and anti-apoptosis activities of compound 39 against LPS-induced tissue and cell damage, and revealed the mechanisms underlying those processes.

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.

Pharmacologic Overview of Chlorogenic Acid and its Metabolites in Chronic Pain and Inflammation

BACKGROUND

Natural phenolic compounds in medicinal herbs and dietary plants are antioxidants which play therapeutic or preventive roles in different pathological situations, such as oxidative stress and inflammation. One of the most studied phenolic compounds in the last decade is chlorogenic acid (CGA), which is a potent antioxidant found in certain foods and drinks.

OBJECTIVE

This review focuses on the anti-inflammatory and antinociceptive bioactivities of CGA, and the putative mechanisms of action are described. Ethnopharmacological reports related to these bioactivities are also reviewed.

MATERIALS AND METHODS

An electronic literature search was conducted by authors up to October 2019. Original articles were selected.

RESULTS

CGA has been shown to reduce inflammation and modulate inflammatory and neuropathic pain in animal models.

CONCLUSION

The consensus of the literature search was that systemic CGA may facilitate pain management via bolstering antioxidant defenses against inflammatory insults.

Protective effects of HY1702 on lipopolysaccharide-induced mild acute respiratory distress syndrome in mice

Acute respiratory distress syndrome is an inflammatory disease with no effective pharmacological treatment. We investigated the therapeutic effect of HY1702, a new small molecule diterpene obtained from the processing and modification of Glaucocalyxin A and may exhibit anti-inflammatory activity. Specifically, we studied the anti-inflammatory effects of HY1702 on lipopolysaccharide-induced inflammatory responses in RAW264.7 and THP-1 cells in vitro and its protective efficacy on lipopolysaccharide-induced mild acute respiratory distress syndrome in mice.

Our results showed that HY1702 significantly decreased lipopolysaccharide-induced inflammatory cytokine expression in RAW264.7 and THP-1 cells and attenuated the secretion of nitric oxide and prostaglandin E2 by down-regulating the expression of inducible nitric oxide synthase and cyclooxygenase 2 in RAW264.7 cells. In mice with lipopolysaccharide-induced mild acute respiratory distress syndrome, HY1702 alleviated histological alterations in the lungs and reduced the alveolar cavity protein leakage and inflammatory cytokine expression in murine bronchial alveolar lavage fluid. HY1702 decreased the myeloperoxidase activity and lung wet to dry weight ratio. In our mechanism studies in lipopolysaccharide-exposed RAW264.7 cells, HY1702 suppressed the inflammation stimulated by lipopolysaccharide through inhibiting phosphorylation of inhibitor of nuclear factor κB kinase subunit α/β (IKKα/β) and inhibitor of nuclear factor κB subunit α (IκBα), further affecting the nuclear transfer of phosphorylated p65. Meanwhile, phosphorylation of p38 mitogen-activated protein (MAP) kinase and extracellular signal-regulated kinase (ERK) was inhibited. These data suggest that HY1702 can reduce inflammation on lipopolysaccharide-stimulated macrophages and attenuate the symptoms of mild acute respiratory distress syndrome in a murine model by regulating the nuclear factor κB and MAP kinase signalling pathways.

Chlorogenic acid: A comprehensive review of the dietary sources, processing effects, bioavailability, beneficial properties, mechanisms of action, and future directions

Chlorogenic acids (CGAs), a group of hydroxycinnamates, are generally abundant in everyday foods and beverages, most prominently in certain coffee drinks. Among them, the chlorogenic acid (CGA), also termed as 5-O-caffeoylquinic acid (5-CQA), is one of the most abundant, highly functional polyphenolic compounds in the human diet. The evidence of its health benefits obtained from clinical studies, as well as basic research, indicates an inverse correlation between 5-CQA consumption and a lower risk of metabolic syndromes and chronic diseases. This review focuses on the beneficial properties for health and mechanisms of action of 5-CQA, starting with its history, isomers, dietary sources, processing effects, preparation methods, pharmacological safety evaluation, and bioavailability. It also provides the possible molecular mechanistic bases to explain the health beneficial effects of 5-CQA including neuroprotective, cardiovascular protective, gastrointestinal protective, renoprotective, hepatoprotective, glucose and lipid metabolism regulatory, and anticarcinogenic effects. The information summarized here could aid in the basic and clinical research on 5-CQA as a natural dietary additive, potential drug candidate, as well as a natural health promoter.

Chlorogenic acid prevents vancomycin-induced nephrotoxicity without compromising vancomycin antibacterial properties

Vancomycin (VCM) is an effective chemotherapeutic agent commonly used against gram-positive microorganisms but has serious nephrotoxic side effects that limit its effectiveness. New therapeutics and strategies are urgently needed to combat VCM associated nephrotoxicity. In this study, we determined the protective effect of chlorogenic acid (CA) in a rat model of VCM-induced nephrotoxicity. VCM administration led to markedly elevated blood urea nitrogen and serum creatinine levels that could be prevented with CA co-administration. VCM-mediated oxidative stress was also significantly attenuated by CA as reflected by decreased malondialdehyde and nitric oxide in VCM-treated kidneys. CA administration also prevented the VCM-mediated decrease in the renal antioxidative enzyme activities of glutathione reductase, glutathione peroxidase, and catalase and led to increased levels of reduced glutathione that had been depleted by VCM. Moreover, CA administration clearly inhibited VCM-induced expression of nuclear factor-kappa B, inducible nitric oxide synthase and the downstream pro-inflammatory mediators tumor necrosis factor-α and interleukins 1β and 6. Apoptotic markers were also markedly down-regulated with CA. Overall, CA treatment mitigated VCM-induced oxidative and nitrosative stresses and countered the apoptotic and inflammatory effects of VCM. Notably, CA did not affect the antibacterial activity of VCM in vitro.

Aloin suppresses lipopolysaccharide-induced acute lung injury by inhibiting NLRP3/NF-κB via activation of SIRT1 in mice

OBJECTIVE

The purpose of this study was to explore the protective effects and potential mechanisms of aloin on lipopolysaccharide (LPS)-induced acute lung injury (ALI).

METHODS

Mice were pretreatment with aloin 1 h before LPS administration. The number of inflammatory cells and the levels of TNF-α and IL-1β was detected. The lung histopathological changes, wet/dry ratio, MPO activity, GSH, MDA, SOD, and the expression of NF-κB and NLRP3 inflammasome were measured.

RESULTS

The results showed that aloin significantly inhibited the number of total cells, neutrophils, and macrophages, as well as the levels of TNF-α and IL-1β in BALF induced by LPS. In addition, pretreatment with aloin also inhibited LPS-induced lung histopathological injuries, lung wet/dry ratio, MPO activity, and MDA content. The levels of GSH and SOD were decreased by LPS and treatment of aloin could increase the levels of GSH and SOD. To study the protective mechanisms of alion on LPS-induced ALI, the expression of SIRT1, NF-κB and NLRP3 inflammasome were tested. We found that aloin significantly inhibited the activation of NF-κB and NLRP3 inflammasome in ALI induced by LPS. Meanwhile, aloin was found to increase the expression of SIRT1 and inhibition of SIRT1 by EX-527 reversed the protective effects of aloin.

CONCLUSIONS

These results suggest that aloin exerts its protective effects on LPS-induced ALI by activation SIRT1, which subsequently results in the suppression of NF-κB and NLRP3 inflammasome.

Functional Ingredients based on Nutritional Phenolics. A Case Study against Inflammation: Lippia Genus

Epidemiological studies have reported convincing evidence that natural dietary compounds may modify inflammation, it being an important event described in the pathophysiology of age-related infirmity. Among different dietary components, nutritional phenolics have demonstrated links to a lower risk of inflammation in the most common degenerative and chronic diseases. In this way, the healthy potential of phenolics against inflammation and the emergence of new functional ingredients have caused an enhancement of nutraceutical and functional food formulation. The present review focuses on: (a) nutritional phenolics and their effects on inflammation and (b) functional ingredients based on phenolic compounds with anti-inflammatory properties. Furthermore, the emerging interest in health-promoting products by consumers has caused an increase in the demand for functional products and nutraceuticals. Additionally, this review includes a case study of the Lippia genus, which has shown anti-inflammatory effects claiming to be a natural alternative for the management of this physiological disorder. This report is a practical tool for healthcare providers.

Bardoxolone treatment alleviates lipopolysaccharide (LPS)-induced acute lung injury through suppressing inflammation and oxidative stress regulated by Nrf2 signaling

Nuclear factor-erythroid 2 related factor 2 (Nrf2) plays critical roles in attenuating various inflammation- and oxidative stress-induced diseases, including acute lung injury (ALI). Bardoxolone (Bard), a synthetic triterpenoid based on natural product oleanolic acid, is one of the most potent Nrf2 activator. However, if Bard could prevent lipopolysaccharide (LPS)-induced ALI by inducing Nrf2 activation and its down-streaming signals, is still poorly understood. In this study, we attempted to explore the protective effect of Bard on ALI and the underlying molecular mechanisms. The results indicated that Bard significantly attenuated ALI through reducing the lung wet/dry weight ratio and protein concentration, neutrophil infiltration, malondialdehyde (MDA) and myeloperoxidase (MPO) levels, and improving superoxide dismutase (SOD) and glutathione (GSH) activities. In addition, Bard effectively ameliorated histopathological alterations, reactive oxygen species (ROS) production, pro-inflammatory cytokines release, and the expression of inducible NO synthase (iNOS), cyclooxygenase-2 (COX2) and high mobility group box 1 (HMGB1). Moreover, the inhibitory role of Bard in inflammation was also attributed to its suppression of nuclear factor-κB (NF-κB) signaling. Furthermore, the activation of mitogen-activated protein kinases (MAPKs) signaling, including p38, extracellular signal-regulated kinase 1/2 (ERK1/2) and c-Jun N-terminal kinase (JNK), induced by LPS was substantially ameliorated by Bard. The beneficial effects of Bard on ALI were confirmed in LPS-incubated cells in vitro. Meanwhile, the in vitro studies also demonstrated that Bard-improved ALI was largely due to its role in inducing Nrf2 signaling through a dose-dependent manner. Importantly, we found that Bard-attenuated histological changes, inflammation, ROS production, NF-κB and MAPKs signaling in Nrf2^+/+ mice were significantly abolished in mice with Nrf2 knockout. Therefore, our study for the first time provided evidence that Bard could effectively ameliorate LPS-induced ALI by reducing oxidative stress and inflammation mainly through the activation of Nrf2 signaling.

Regulation of the levels of health promoting compounds: lupeol, mangiferin and phenolic acids in the pulp and peel of mango fruit: a review

There is a demand for feasible methodologies that can increase/maintain the levels of health-promoting phytochemicals in horticultural produce, due to strong evidence that these compounds can reduce risk of chronic diseases. Mango (Mangifera indica L.), ranks fifth among the most cultivated fruit crops in the world, is naturally rich in phytochemicals such as lupeol, mangiferin and phenolic acids (e.g. gallic acid, chlorogenic acid and vanillic acid). Yet, there is still much scope for up-regulating the levels of these compounds in mango fruit through manipulation of different preharvest and postharvest practices that affect their biosynthesis and degradation. The process of ripening, harvest maturity, physical and chemical elicitor treatments such as low temperature stress, methyl jasmonate (MeJA), salicylic acid (SA) and nitric oxide (NO) and the availability of enzyme cofactors (Mg²⁺ , Mn²⁺ and Fe²⁺ ) required in terpenoid biosynthesis were identified as potential determinants of the concentration of health-promoting compounds in mango fruit. The effectiveness of these preharvest and postharvest approaches in regulating the levels of lupeol, mangiferin and phenolic acids in the pulp and peel of mango fruit will be discussed. In general spray application of 0.2% iron(II) sulphate (FeSO₄ ) 30 days before harvest, harvest at sprung stage, storage of mature green fruit at 5 °C for 12 days prior to ripening, fumigation of mature green fruit with 10^-5  mol L^-1 and/or 10^-4  mol L^-1 MeJA for 24 h or 20 and/or 40 µL L^-1 NO for 2 h upregulate the levels of lupeol, mangiferin and phenolic acids in pulp and peel of ripe mango fruit. © 2019 Society of Chemical Industry.

Phenolic Compounds from Five Ericaceae Species Leaves and Their Related Bioavailability and Health Benefits

Some species of the Ericaceae family have been intensively studied because of the beneficial health impact, known since ancient times, of their chemical components. Since most studies focus on the effects of fruit consumption, this review aims to highlight the phenolic components present in the leaves. For this purpose, five species from Ericaceae family (bilberry-Vaccinium myrtillus L., lingonberry-V. vitis-idaea L., bog bilberry-V. uliginosum L., blueberry-V. corymbosum L. and bearberry-Arctostapylos uva-ursi L.) were considered, four of which can be found in spontaneous flora. The chemical composition of the leaves revealed three major phenolic compounds: chlorogenic acid, quercetin and arbutin. The health promoting functions of these compounds, such as antioxidant and anti-inflammatory properties that could have preventive effects for cardiovascular disease, neurodegenerative disorders, cancer, and obesity, have been exemplified by both in vitro and in vivo studies in this review. Furthermore, the importance of bioaccessibility and bioavailability of the phenolic compounds have been summarized. The findings highlight the fact that leaves of some Ericaceae species deserve increased attention and should be studied more profoundly for their biological activities, especially those from spontaneous flora.

Anti-inflammatory effects of ivy leaves dry extract: influence on transcriptional activity of NFκB

EA 575® is an ivy leaves dry extract (DER 5-7.5:1, 30% ethanol) used against diseases of the lower respiratory tract associated with productive cough. EA 575® improves symptoms associated with chronic inflammatory bronchial conditions. Compared to its bronchospasmolytic and secretolytic properties, the anti-inflammatory effects of EA 575® are mostly untried. Therefore, we addressed the question of whether the anti-inflammatory effect of EA 575® is due to an impact on the NFκB pathway. NFκB nuclear translocation was visualized by immunofluorescence in J774.2 as well as HEK293 cells. In the latter, a luciferase-based reporter was used to monitor NFκB transcriptional activity. Phosphorylation of RelA and its inhibitor IκB was measured by Western blot analysis. Additionally, changes in the stability of NFκB:IκB complex were shown by protein fragment complementation. Decreased transcriptional activity of NFκB under treatment with EA 575® was also shown for a human monocytic as well as a human lung epithelial cell line. EA 575® is able to inhibit NFκB transcriptional activity by partially inhibiting its translocation to the nucleus after stimulation with TNFα. Furthermore, phosphorylation of IκBα is reduced while phosphorylation of RelA is enhanced after pre-incubation with EA 575®, leading to an enhanced stability of NFκB:IκBα complex. EA 575® has an regulatory impact on the NFκB pathway, possibly by switching specificity of IKK from IκBα to RelA, resulting in enhanced stability of NFκB:IκBα complex and reduced RelA translocation into the nucleus.

Chlorogenic Acid Ameliorates Colitis and Alters Colonic Microbiota in a Mouse Model of Dextran Sulfate Sodium-Induced Colitis

This study evaluated the mitigating effects of dietary chlorogenic acid (CGA) on colon damage and the bacterial profile in a mouse model of dextran sulfate sodium (DSS)-induced colitis. C57BL/6J mice were randomly assigned to receive one of the following treatments: (i) basal diet; (ii) basal diet with 2% CGA; (iii) basal diet with 2.5% DSS or (iv) basal diet with 2% CGA and 2.5% DSS. Following a 2-week pre-treatment period, mice in the DSS and CGA-DSS groups received 2.5% DSS in drinking water for 5 days, while the other two groups received sterile water. Compared to DSS alone, CGA was found to reduce the disease activity index, myeloperoxidase activity and tumor necrosis factor-α levels in colon tissues (P < 0.05). CGA also ameliorated DSS-induced inflammatory responses, reduced colon shortening and decreased the histological scores (P < 0.05). In an evaluation of the relative abundances of bacteria in the fecal microbiota, we found that CGA reversed the decrease in diversity caused by DSS and improved the relative abundance of organisms in the genus Lactobacillus (P < 0.05). These results indicate that CGA maintains intestinal health and reduces DSS-induced colon injury by decreasing the production of pro-inflammatory cytokines and restoring intestinal microbial diversity.

Protective effect of aqueous extract, fractions and phenolic compounds of Hancornia speciosa fruits on the inflammatory damage in the lungs of mice induced by Tityus serrulatus envenomation

Scorpion envenomation has been considered a public health issue around the world. Tityus serrulatus represents a specie of major medical importance in Brazil due to mortality rates of approximately 1% among children and elderly populations. The aim of this work was to evaluate the in vivo anti-inflammatory potential of aqueous extract from Hancornia speciosa fruits, its fractions and its phenolic compounds against T. serrulatus envenomation. After receiving the T. serrulatus venom (TsV, 0.8 mg/kg) intraperitoneally, the animals were treated intravenously with the aqueous extract (20, 30 and 40 mg/kg), the arachnid antivenom (50 μL/animal), the dichloromethane, ethyl acetate and n-butanol fractions (20 mg/kg) as well as rutin and chlorogenic acid (2, 2.5 and 5 mg/kg). The treatment with the aqueous extract, fractions and phenolic compounds decreased the migration of leukocytes to the peritoneal cavity and reduced the levels of IL-1β, IL-6 and IL-12. Moreover, the pulmonary histopathologic analysis showed a reduction in both interstitial and alveolar edema, as well as in the leukocytes infiltration and vascular ectasia in the mice's lungs, which evidences a protective effect attributed to H. speciosa. This is the first study that demonstrates the inhibitory potential of the aqueous extract from H. speciosa fruits against inflammation induced by TsV. These findings suggest that the bioactive compounds from the aqueous extract, especially chlorogenic acid and rutin, are responsible for the reported anti-inflammatory activity of H. speciosa.

Dietary chlorogenic acid supplementation affects gut morphology, antioxidant capacity and intestinal selected bacterial populations in weaned piglets

Chlorogenic acid (CGA), an ester formed between caffeic acid and quinic acid, is one of the most abundant phenolic acids and is widespread in fruits, vegetables, cereals and tuber crops. Therefore, the present study was conducted to test the hypothesis that dietary supplementation with CGA could improve intestinal health and regulate intestinal selected microbiota in weaned piglets. A total of twenty-four piglets (21 d of age) were randomly assigned to one of four groups according to their initial BW and sex and fed a basal diet (control group) or a basal diet containing 250, 500 and 1000 mg kg-1 CGA, respectively. The whole trial lasted for 28 d. Dietary CGA supplementation increased (P < 0.05) the duodenal villous height and villous height : crypt depth ratio, but decreased (P < 0.05) the F/G ratio and duodenal crypt depth when compared with the control group. Meanwhile, an increase (P < 0.05) in the jejunal villous height and in the ileal villous height : crypt depth ratio were also observed in CGA-fed piglets. Supplementation with CGA significantly increased (P < 0.05) the activity of serum GSH-Px and the activities of duodenal GSH-Px and CAT, upregulated (P < 0.05) the expression of OCLN in the duodenum and jejunum, and decreased (P < 0.05) the ileal MDA content when compared to the control group. In addition, an increase (P < 0.05) in the population of Lactobacillus and a decrease (P < 0.05) in the population of Escherichia coli were observed in the colon of pigs fed CGA diets. Furthermore, pigs fed CGA diets had higher (P < 0.05) propionic and butyric acid concentrations in the colon. Altogether, our results provide evidence that dietary CGA is beneficial for preserving intestinal morphological integrity and selectively regulating intestinal microbiota, which can provide a means to improve gut health and growth performance post-weaning.

Insulin ameliorates pulmonary edema through the upregulation of epithelial sodium channel via the PI3K/SGK1 pathway in mice with lipopolysaccharide‑induced lung injury

Epithelial sodium channel (ENaC) provides the driving force for the removal of edema from the alveolar spaces in acute lung injury (ALI). Our previous study reported that insulin increased the expression of α‑ENaC, possibly via the serum/glucocorticoid‑inducible kinase‑1 (SGK1) pathway in ALI; however, the upstream regulator of SGK1 activity remains unclear. In the current study, C3H/HeN mice were subjected to lipopolysaccharide (LPS)‑induced lung injury without hyperglycemia. Exogenous insulin was administered intravenously using a micro‑osmotic pump, and intratracheal delivery of SGK1 small interfering RNA (siRNA) was performed. Furthermore, alveolar epithelial type II cells transfected with phosphatidylinositol 3‑kinase (PI3K) siRNA or SGK1 siRNA were incubated with insulin. Insulin protected the pulmonary epithelial barrier, reduced the apoptosis of alveolar epithelial cells, attenuated pulmonary edema, improved alveolar fluid clearance, and increased the expression levels of α‑, β‑ and γ‑ENaC in mice. In addition, in alveolar epithelial cells, insulin increased the expression levels of α‑, β‑ and γ‑ENaC, as well as the level of phosphorylated SGK1, which were then inhibited by the selective targeting of PI3K or SGK1 by siRNA. Taken together, the results of the present study demonstrated that insulin protected the lung epithelium and attenuated pulmonary edema through the upregulation of ENaC via the PI3K/SGK1 pathway in LPS‑induced lung injury.