5-Hydroxymethylfurfural Alleviates Inflammatory Lung Injury by Inhibiting Endoplasmic Reticulum Stress and NLRP3 Inflammasome Activation

Anti-inflammatory, Antioxidative, and Moisturizing Effects of Oxyceros horridus Lour. Ethanol Extract in Human Keratinocytes via the p38 Signaling Pathway

Skin is the largest and outermost organ in the human body; it serves as a vital defense mechanism against various external threats. Therefore, it is crucial to maintain its health through protection against harmful substances and adequate moisture levels. This study investigates the anti-inflammatory, antioxidant, and moisturizing properties of Oxyceros horridus Lour. (Oh-EE) in human keratinocytes. Oh-EE demonstrates potent antioxidant activity and effectively protects against oxidative stress induced by external stimuli such as UVB radiation and H2O2. Additionally, it exhibits significant anti-inflammatory effects proven by its ability to downregulate the expression of pro-inflammatory cytokines, namely COX-2 and IL-6. The study also explores the involvement of the AP-1 pathway, highlighting the ability of Oh-EE to suppress the expression of p38 and its upstream regulator, MKK3/6, under UVB-induced conditions. Interestingly, Oh-EE can activate the AP-1 pathway in the absence of external triggers. Furthermore, Oh-EE enhances skin moisture by upregulating the expression of key genes involved in skin hydration, namely HAS3 and FLG. These findings underscore the potential of Oh-EE as a versatile ingredient in skincare formulations, providing a range of skin benefits. Further research is warranted to comprehensively understand the underlying mechanisms through which Oh-EE exerts its effects.

Gracilaria chorda subcritical water ameliorates hepatic lipid accumulation and regulates glucose homeostasis in a hepatic steatosis cell model and obese C57BL/6J mice

ETHNOPHARMACOLOGICAL RELEVANCE

Red seaweed, known as Rhodophyta, has a long history of use in traditional Asian medicine, including Traditional Chinese Medicine and Ayurveda. It is believed to have cooling and detoxification properties. Red seaweed species, such as Gracilaria, have been used in traditional remedies to address various conditions, such as inflammation, thyroid disorders, and digestive issues.

AIM OF THE STUDY

Obesity is a risk factor of hepatic steatosis, a hallmark of non-alcoholic fatty liver disease (NAFLD) that affects nearly 25% of the worldwide population. Gracilaria chorda (GC) contains bioactive peptides that may be applicable in the prevention of metabolic syndrome diseases. This study investigated the effects of GC subcritical water extract at 210 °C (GCSW210) on preventing liver injury and lipid and glucose dysregulation in an oleic acid (OA)-induced hepatic steatosis cell model (HepG2) and high-fat diet (HFD)-induced obese animal model (C57BL/6J mice).

MATERIALS AND METHODS

Human hepatoma HepG2 cells were exposed to 0.1 mM OA for 24 h to induce hepatic steatosis and C57BL/6J mice were fed a HFD for 13 weeks. For lipid accumulation, triglyceride (TG) content was measured in both models, along with free fatty acid (FFA), plasma glucose, and insulin levels in HFD-fed mice. Protein expression of master regulators of adipogenesis and lipogenesis, as well as cholesterol and mitochondrial biosynthesis, was studied via western blotting in hepatic steatosis-induced in vitro and in vivo models. In addition, protein expression of the insulin signaling cascade in skeletal muscle tissues of HFD-fed mice was studied.

RESULTS

GCSW210 significantly decreased lipid accumulation in HepG2 cells exposed to OA and suppressed the expression of lipogenic factors, such as sterol regulatory element-binding protein (SREBP)-1c and fatty acid synthase. In addition, GCSW210 abrogated transcription factors related to cholesterol biosynthesis, such as SREBP-2 and low-density lipoprotein receptor. Similarly, FFA, TG, serum glutamic acid, aspartate transaminase, alanine transferase, plasma glucose, and insulin levels were also significantly reduced in GCSW210-treated HFD-fed mice, which were comparable to the positive control mice treated with Garcinia cambogia extract. Additionally, GCSW210 enhanced the phosphorylation of AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase in the hepatic tissues of HFD-fed mice. Moreover, GCSW210 treatment improved insulin signal transduction by reducing insulin receptor substrate 1 Ser307 phosphorylation and elevated phosphatidylinositol 3-kinase/protein kinase B and glucose transporter type 4 protein expression in muscle tissue. 5-Hdroxymethylfufural (5-HMF) was confirmed to be active substances isolated from GCSW210 through LC-PDA and LC-MS.

CONCLUSIONS

GCSW210 significantly regulated glucose metabolism, alleviated insulin resistance (IR) induced by high fatty acid synthesis and lipid accumulation, and elevated de novo lipogenesis by activating AMPK phosphorylation in both the liver and muscle tissues of HFD-fed mice. GCSW210 may be a potential functional food for preventing HFD-induced metabolic diseases, such as IR, NAFLD, and type 2 diabetes mellitus.

Xuanbai Chengqi Decoction alleviates acute lung injury by inhibiting NLRP3 inflammasome

ETHNOPHARMACOLOGICAL RELEVANCE

Acute lung injury/acute respiratory distress syndrome (ALI/ARDS) is a prevalent critical respiratory disorder caused mostly by infection and other factors. However, effective drug therapies are currently lacking. Xuanbai Chengqi Decoction (XCD), a traditional Chinese medicine (TCM) prescription, is commonly employed to treat lung diseases. It has been recommended by Chinese health authorities as one of the TCM prescriptions for COVID-19. Nonetheless, its underlying mechanism for the treatment of ALI has not been fully understood.

AIM OF THE STUDY

The study aims to investigate the therapeutic effect of XCD on lipopolysaccharide (LPS) -induced ALI in mice and explore its anti-inflammatory mechanism involving pyroptosis.

MATERIALS AND METHODS

Ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) was employed to identify the active compounds of XCD, and quantitative analysis of the main compounds was conducted. Male C57BL/6J mice were given different doses of XCD (4.5 and 9.0 g/kg/day) or dexamethasone (5 mg/kg/day) by oral gavage for 5 consecutive days. Subsequently, ALI was induced by injecting LPS (20 mg/kg) intraperitoneally 2 h after the last administration, and serum and lung tissues were collected 8 h later. J774A.1 cells were pretreated with different doses of XCD (100, 200, 400 μg/ml) for 12 h, then incubated with LPS (1 μg/ml) for 4 h and ATP (1 mM) for 2 h to induce pyroptosis. Supernatant and cells were collected. Moreover, J774A.1 cells were transfected with an NLRP3 overexpression plasmid for 24 h, followed by subsequent experiments with XCD (400 μg/ml). Lung histopathological changes were evaluated using hematoxylin and eosin (HE) staining. To assess the efficacy of XCD on ALI/ARDS, the levels of inflammatory factors, chemokines, and proteins associated with NLRP3 inflammasome signaling pathway were evaluated.

RESULTS

XCD was found to ameliorate lung inflammation injury in ALI mice, and reduce the protein expression of TNF-α, IL-1β, and IL-6 in both mouse serum and J774A.1 cell supernatant. Meanwhile, XCD significantly decreased the mRNA levels of IL-1β, pro-IL-1β, CXCL1, CXCL10, TNF-α, NLRP3, NF-κB P65, and the protein expression of NLRP3, Cleaved-Caspase1, and GSDMD-N in the lung and J774A.1 cells. These effects were consistent with the NLRP3 inhibitor MCC950. Furthermore, overexpression of NLRP3 reversed the anti-inflammatory effect of XCD.

CONCLUSION

The therapeutic mechanism of XCD in ALI treatment may involve alleviating inflammatory responses in lung tissues by inhibiting the activation of the NLRP3 inflammasome-mediated pyroptosis in macrophages.

Sivelestat sodium alleviated lipopolysaccharide-induced acute lung injury by improving endoplasmic reticulum stress

Acute lung injury (ALI) is a common inflammatory respiratory disorder characterized by a high incidence and mortality rate. This study aimed to investigate the potential therapeutic effects of the neutrophil elastase inhibitor Sivelestat sodium (SIV) in improving endoplasmic reticulum stress (ERS) while treating lipopolysaccharide (LPS)-induced ALI. An ALI model was established using LPS induction. The effects of SIV on ALI were observed both in vivo and in vitro, along with its impact on ERS. Lung tissue damage was assessed using Hematoxylin-eosin (H&E) staining. Lung edema was measured by the lung wet/dry weight ratio. The expression levels of protein kinase R-like ER kinase (PERK), Phospho-protein kinase R-like ER kinase (p-PERK), activating transcription factor 4 (ATF4), eukaryotic translation initiation factor 2α (EIF2a), phosphorylated α subunit of eukaryotic initiation factor 2α (P-EIF2a), and C/EBP homologous protein (CHOP) were analyzed by Western blotting in vivo and in vitro. The levels of tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) in Lung tissue samples supernatants were measured by ELISA. Oxidative stress markers were measured by ELISA. Apoptosis was measured using the TUNEL assay. Apoptosis-associated proteins B-cell lymphoma-2 (Bcl-2)、Bcl2-associated × (Bax)、caspase-3 were evaluated through Western blotting in vivo and in vitro. The expression levels of ERS-related proteins, including p-PERK, ATF4, P-EIF2a, and CHOP, were significantly increased in the LPS-induced ALI model. However, SIV markedly reduced the expression levels of these proteins, suppressing the LPS-induced ERS response. Further investigations revealed that SIV exerted a protective effect on ALI by alleviating lung tissue damage and apoptosis, improving lung function, and reducing inflammation and oxidative stress levels. However, when SIV was co-administered with Tunicamycin (TUN), TUN blocked the beneficial effects of SIV on ERS and reversed the protective effects of SIV on ALI. In conclusion, SIV alleviated lung tissue damage and apoptosis, improving lung function, and reducing inflammation and oxidative stress in LPS-induced ALI by improving ERS.

5-Hydroxymethylfurfural Ameliorates Allergic Inflammation in HMC-1 Cells by Inactivating NF-κB and MAPK Signaling Pathways

Allergic inflammation is the foundation of multiple allergic disorders, such as allergic rhinitis and asthma. Mast cells are effector cells that initiate inflammatory response. 5-hydroxymethylfurfural (5-HMF), a furfural compound, is the heat-processed product of various fruit, foods, drinks, as well as some Chinese herbal medicines. 5-HMF was previously reported to inhibit mast cell activation. Our study aimed to explore the functions of 5-HMF in both phorbol 12-mystate 13-acetate (PMA) plus calcium ionophore (A23187)-induced allergic inflammation in human mast cell line HMC-1 and ovalbumin (OVA)-induced asthma mouse models. HMC-1 cells were pretreated with 5-HMF and then stimulated by PMA+A23187. The cytotoxicity of 5-HMF on HMC-1 cells was evaluated by MTT assay. Histamine content in cell supernatants was measured by the o-phthaldialdehyde spectrofluorometric procedure. Intracellular calcium was determined using the fluorescent dye Fura-2AM. The production and expression of pro-inflammatory cytokines were detected by ELISA and RT-qPCR. Caspase-1 colorimetric assay was employed to examine the enzymatic activity of caspase-1. Asthma mouse models were induced by OVA sensitization. The bronchoalveolar lavage fluid (BALF) and blood samples were collected for the detection of total and differential cell count as well as aspartate aminotransferase (AST), alanine aminotransferase (ALT), OVA-immunoglobulin E (OVA-IgE), OVA-immunoglobulin G1 (OVA-IgG1), and pro-inflammatory cytokine levels. The left lung of mouse was dissected for histopathological examination by hematoxylin and eosin (H&E) staining. The protein expression of pro-caspase-1 and the phosphorylation of NF-κB and MAPK pathway-associated molecules were assessed by Western blotting. Our findings revealed that 5-HMF efficiently suppressed the PMA+A23187-induced enhancement in histamine production and intracellular calcium in HMC-1 cells. Pro-inflammatory cytokine production and expression in HMC-1 cells were elevated after PMA plus A23187 stimulation, which, however, were inhibited by pretreatment of 5-HMF. Additionally, 5-HMF suppressed the activity of caspase-1 and the phosphorylation of NF-κB and MAPK-associated molecules including p65 NF-κB, p38 MAPK, ERK, and JNK in HMC-1 cells. In vivo experiments demonstrated that 5-HMF treatment reduced the lung/body weight index and total and differential (macrophages, neutrophils, lymphocytes, and eosinophils) cell counts in BALF of asthmatic mice, but exerted no influence on serum AST and ALT levels. Besides, 5-HMF reduced serum OVA-IgE and OVA-IgG1 levels, mitigated lung inflammation, and inhibited the NF-κB and MAPK signaling pathways in asthma mouse models. 5-HMF mitigates allergic inflammation in asthma by inactivating caspase-1 and NF-κB and MAPK signaling pathways.

Sepsis-Induced Acute Lung Injury Is Alleviated by Small Molecules from Dietary Plants via Pyroptosis Modulation

Sepsis-induced acute respiratory distress syndrome (ARDS) has high morbidity and mortality, and it has three major pathogeneses, namely alveolar-capillary barrier destruction, elevated gut permeability, and reduced neutrophil extracellular traps (NETS), all of which are pyroptosis-involved. Due to limitations of current agents like adverse reaction superposition, inevitable drug resistance, and relatively heavier financial burden, naturally extracted small-molecule compounds have a broad market even though chemically modified drugs have straightforward efficacy. Despite increased understanding of the molecular biology and mechanism underlying sepsis-induced ARDS, there are no specific reviews concerning how small molecules from dietary plants alleviate sepsis-induced acute lung injury (ALI) via regulating pyroptotic cell death. Herein, we traced and reviewed the molecular underpinnings of sepsis-induced ALI with a focus on small-molecule compounds from dietary plants, the top three categories of which are respectively flavonoids and flavone, terpenoids, and polyphenol and phenolic acids, and how they rescued septic ALI by restraining pyroptosis.

Chimaphila umbellata; a biotechnological perspective on the coming-of-age prince's pine

Chimaphila umbellata has been studied for almost two centuries now, with the first paper exploring the phytochemistry of the plant published in 1860. Almost all contemporary studies focus on the biotechnological advances of C. umbellata including its utilization as a natural alternative in the cosmetic, food, biofuel, and healthcare industry, with a special focus on its therapeutic uses. This literature review critically investigates the significance and applications of secondary metabolites extracted from the plant and presses on the biotechnological approaches to improve its utilization. C. umbellata is home to many industrially and medicinally important phytochemicals, the majority of which belong to phenolics, sterols, and triterpenoids. Other important compounds include 5-hydroxymethylfurfural, isohomoarbutin, and methyl salicylate (the only essential oil of the plant). Chimaphilin is the characteristic phytochemical of the plant. This review focuses on the phytochemistry of C. umbellata and digs into their chemical structures and attributes. It further discusses the challenges of working with C. umbellata including its alarming conservation status, problems with in-vitro cultivation, and research and development issues. This review concludes with recommendations based on biotechnology, bioinformatics, and their crucial interface.

Mechanism of miR-338-3p in sepsis-induced acute lung injury via indirectly modulating ATF4

Sepsis is recognized as an inflammation-related syndrome in response to invading pathogens. Many patients suffer from sepsis including transplant recipients. Lipopolysaccharide (LPS) is known to trigger sepsis-related organ dysfunction. This study expounded on the possible effect of microRNA (miR)-338-3p in sepsis-induced acute lung injury (ALI). Firstly, human bronchial epithelial cell line 16HBE received LPS treatment to establish the cell models of sepsis-induced ALI. The expression patterns of miR-338-3p, long non-coding RNA OPA-interacting protein 5 antisense transcript 1 (lncRNA OIP5-AS1), and activating transcription factor 4 (ATF4) in 16HBE cells were examined. Afterwards, 16HBE cell viability, the apoptosis rate, and the levels of inflammation and lactate dehydrogenase (LDH) were determined to assess the degree of cell injury. We disclosed that LPS treatment triggered 16HBE cell injury, downregulated miR-338-3p, and upregulated OIP5-AS1 and ATF4. miR-338-3p overexpression repressed LPS-induced 16HBE cell injury. miR-338-3p diminished OIP5-AS1 stability via binding to OIP5-AS1 and downregulated OIP5-AS1 expression and OIP5-AS1 can enhance ATF4 mRNA stability and upregulate ATF4 mRNA level. The rescue experiments showed that ATF4 overexpression aggravated LPS-induced 16HBE cell injury. Overall, miR-338-3p overexpression decreased OIP5-AS1 expression and stability and further downregulated ATF4 mRNA level, thereby mitigating LPS-induced 16HBE cell injury.

Antimalarial efficacy and toxicological assessment of medicinal plant ingredients of Prabchompoothaweep remedy as a candidate for antimalarial drug development

BACKGROUND

Drug resistance exists in almost all antimalarial drugs currently in use, leading to an urgent need to identify new antimalarial drugs. Medicinal plant use is an alternative approach to antimalarial chemotherapy. This study aimed to explore potent medicinal plants from Prabchompoothaweep remedy for antimalarial drug development.

METHODS

Forty-eight crude extracts from Prabchompoothaweep remedy and its 23 plants ingredients were investigated in vitro for antimalarial properties using Plasmodium lactate dehydrogenase (pLDH) enzyme against Plasmodium falciparum K1 strain and toxicity effects were evaluated in Vero cells. The plant with promising antimalarial activity was further investigated using gas chromatography-mass spectrometry (GC-MS) to identify phytochemicals. Antimalarial activity in mice was evaluated using a four-day suppressive test against Plasmodium berghei ANKA at dose of 200, 400, and 600 mg/kg body weight, and acute toxicity was analyzed.

RESULTS

Of the 48 crude extracts, 13 (27.08%) showed high antimalarial activity against the K1 strain of P. falciparum (IC₅₀ <  10 μg/ml) and 9 extracts (18.75%) were moderately active (IC₅₀ = 11-50 μg/ml). Additionally, the ethanolic extract of Prabchompoothaweep remedy showed moderate antimalarial activity against the K1 strain of P. falciparum (IC₅₀ = 14.13 μg/ml). Based on in vitro antimalarial and toxicity results, antimalarial activity of the aqueous fruit extract of Terminalia arjuna (IC₅₀ = 4.05 μg/ml and CC₅₀ = 219.6 μg/ml) was further studied in mice. GC-MS analysis of T. arjuna extract identified 22 compounds. The most abundant compounds were pyrogallol, gallic acid, shikimic acid, oleamide, 5-hydroxymethylfurfural, 1,1-diethoxy-ethane, quinic acid, and furfural. Analysis of the four-day suppressive test indicated that T. arjuna extract at dose of 200, 400, and 600 mg/kg body weight significantly suppressed the Plasmodium parasites by 28.33, 45.77, and 67.95%, respectively. In the acute toxicity study, T. arjuna extract was non-toxic at 2000 mg/kg body weight.

CONCLUSIONS

The aqueous fruit extract of T. arjuna exerts antimalarial activity against Plasmodium parasites found in humans (P. falciparum K1) and mice (P. berghei ANKA). Acute toxicity studies showed that T. arjuna extract did not show any lethality or adverse effects up to a dose of 2000 mg/kg.

A bacterial phospholipid phosphatase inhibits host pyroptosis by hijacking ubiquitin

The inflammasome-mediated cleavage of gasdermin D (GSDMD) causes pyroptosis and inflammatory cytokine release to control pathogen infection, but how pathogens evade this immune response remains largely unexplored. Here we identify the known protein phosphatase PtpB from Mycobacterium tuberculosis as a phospholipid phosphatase inhibiting the host inflammasome-pyroptosis pathway. Mechanistically, PtpB dephosphorylated phosphatidylinositol-4-monophosphate and phosphatidylinositol-(4,5)-bisphosphate in host cell membrane, thus disrupting the membrane localization of the cleaved GSDMD to inhibit cytokine release and pyroptosis of macrophages. Notably, this phosphatase activity requires PtpB binding to ubiquitin. Disrupting phospholipid phosphatase activity or the ubiquitin-interacting motif of PtpB enhanced host GSDMD-dependent immune responses and reduced intracellular pathogen survival. Thus, pathogens inhibit pyroptosis and counteract host immunity by altering host membrane composition.

Angiopteris cochinchinensis de Vriese Ameliorates LPS-Induced Acute Lung Injury via Src Inhibition

Growing demand for treatment options against acute lung injury (ALI) emphasizes studies on plant extracts harboring anti-inflammatory effects. According to GC-MS analysis, Angiopteris cochinchinensis de Vriese consists of various flavonoids with anti-inflammatory activities. Thus, in this study, the anti-inflammatory effects of an extract of Angiopteris cochinchinensis de Vriese (Ac-EE) were assessed using RAW264.6 murine macrophages and a lipopolysaccharide (LPS)-induced ALI model. Ac-EE reduced the nitric oxide production in murine macrophages increased by LPS induction. Moreover, protective effects of Ac-EE on lung tissue were demonstrated by shrinkage of edema and lung injury. Reduced neutrophil infiltration and formation of hyaline membranes were also detected in lung tissues after H&E staining. Semiquantitative RT-PCR, quantitative real-time PCR, and ELISA showed that Ac-EE inhibits the production of proinflammatory mediators, including iNOS and COX-2, and cytokines, such as TNF-α, IL-1β, and IL-6. An Ac-EE-mediated anti-inflammatory response was derived from inhibiting the NF-κB signaling pathway, which was evaluated by luciferase reporter assay and Western blotting analysis. A cellular thermal shift assay revealed that the prime target of Ac-EE in alleviating inflammation was Src. With its direct binding with Src, Angiopteris cochinchinensis de Vriese significantly mitigates lung injury, showing possibilities of its potential as an effective botanical drug.

The Human Monocyte-A Circulating Sensor of Infection and a Potent and Rapid Inducer of Inflammation

Monocytes were previously thought to be the precursors of all tissue macrophages but have recently been found to represent a unique population of cells, distinct from the majority of tissue macrophages. Monocytes and intestinal macrophages seem now to be the only monocyte/macrophage populations that originate primarily from adult bone marrow. To obtain a better view of the biological function of monocytes and how they differ from tissue macrophages, we have performed a quantitative analysis of its transcriptome in vivo and after in vitro stimulation with E. coli LPS. The monocytes rapidly responded to LPS by producing extremely high amounts of mRNA for the classical inflammatory cytokines, IL-1α, IL-1β, IL-6 and TNF-α, but almost undetectable amounts of other cytokines. IL-6 was upregulated 58,000 times, from almost undetectable levels at baseline to become one of the major transcripts already after a few hours of cultivation. The cells also showed very strong upregulation of a number of chemokines, primarily IL-8, Ccl2, Ccl3, Ccl3L3, Ccl20, Cxcl2, Cxcl3 and Cxcl4. IL-8 became the most highly expressed transcript in the monocytes already after four hours of in vitro culture in the presence of LPS. A high baseline level of MHC class II chains and marked upregulation of super oxide dismutase (SOD2), complement factor B, complement factor C3 and coagulation factor 3 (F3; tissue factor) at four hours of in vitro culture were also observed. This indicates a rapid protective response to high production of oxygen radicals, to increase complement activation and possibly also be an inducer of local coagulation. Overall, these findings give strong support for monocytes acting primarily as potent mobile sensors of infection and rapid activators of a strong inflammatory response.