Casticin inhibits lipopolysaccharide-induced acute lung injury in mice

Casticin ameliorates osteoarthritic cartilage damage in rats through PI3K/AKT/HIF-1α signaling

Knee osteoarthritis (KOA) is a chronic, disabling knee joint lesion in which degeneration and defects in articular cartilage are the most important features. Casticin (CAS) is a flavonoid extracted from the Chinese herb Vitex species that has anti-inflammatory and antitumor effects. The aim of this study was to investigate the therapeutic and mechanistic effects of CAS on cartilage damage in KOA. A KOA rat model was established by anterior cruciate ligament transection (ACLT), and cartilage morphological changes were assessed by histological analysis and micro-CT scans. Subsequently, chondrocytes were treated with 10 ng/mL IL-1β to establish an OA model. CCK-8 assays and EdU assays were performed to assess the viability of CAS-treated chondrocytes. Western blotting, flow cytometry and Hoechst 33342/PI Double Stain were used to detect chondrocyte apoptosis. Western blotting, qRT‒PCR and ELISA were used to detect changes in inflammatory mediators. In addition, cartilage matrix-related indices were detected by Western blotting, qRT‒PCR and immunofluorescence (IF) analysis. Immunohistochemistry (IHC) and Western blotting were performed to detect the expression of p-PI3K, p-AKT and HIF-1α in vivo and in vitro. Micro-CT, pathological sections and related scores showed that CAS improved the alterations in bony structures and reduced cartilage damage and osteophyte formation in the ACLT model. In vivo, CAS attenuated IL-1β-induced cartilage matrix degradation, apoptosis and the inflammatory response. In addition, CAS inhibited the expression of the PI3K/AKT/HIF-1α signaling pathway in the ACLT animal model and IL-1β cell model. CAS may ameliorate cartilage damage in OA by inhibiting the PI3K/AKT/HIF-1α signaling pathway, suggesting that CAS is a potential strategy for the treatment of OA.

Identification of a novel role for TL1A/DR3 deficiency in acute respiratory distress syndrome that exacerbates alveolar epithelial disruption

Alveolar epithelial barrier is a potential therapeutic target for acute respiratory distress syndrome (ARDS). However, an effective intervention against alveolar epithelial barrier has not been developed. Here, based on single-cell RNA and mRNA sequencing results, death receptor 3 (DR3) and its only known ligand tumor necrosis factor ligand-associated molecule 1A (TL1A) were significantly reduced in epithelium from an ARDS mice and cell models. The apparent reduction in the TL1A/DR3 axis in lungs from septic-ARDS patients was correlated with the severity of the disease. The examination of knockout (KO) and alveolar epithelium conditional KO (CKO) mice showed that TL1A deficiency exacerbated alveolar inflammation and permeability in lipopolysaccharide (LPS)-induced ARDS. Mechanistically, TL1A deficiency decreased glycocalyx syndecan-1 and tight junction-associated zonula occludens 3 by increasing cathepsin E level for strengthening cell-to-cell permeability. Additionally, DR3 deletion aggravated barrier dysfunction and pulmonary edema in LPS-induced ARDS through the above mechanisms based on the analyses of DR3 CKO mice and DR3 overexpression cells. Therefore, the TL1A/DR3 axis has a potential value as a key therapeutic signaling for the protection of alveolar epithelial barrier.

Traditional uses, phytochemistry, and pharmacology of genus Vitex (Lamiaceae)

Vitex, the genus of the family Lamiaceae, comprises of about 230 species mostly distributed in the warm regions of Europe and temperate regions of Asia. Several Vitex species have been used as folk medicine in different countries for the treatment of various kinds of diseases and ailments. The main aim of this review is to collect and analyze the scientific information available about the Vitex species regarding their chemical constituents and pharmacological activities. The phytochemical investigation of various Vitex species has resulted in the isolation of about 556 chemical constituents belong to various chemical category viz. iridoids, diterpenoids, triterpenoids, flavonoids, lignans, sesquiterpenoids, monoterpenoids, ecdysteroids, and others. The crude extracts of different Vitex species as well as pure phytochemicals exhibited a wide spectrum of in-vitro and in-vivo pharmacological activities. In the present review, the scientific literature data on the ethnopharmacological, phytochemical, and pharmacological investigations on the genus Vitex are summarized. More attention should be given in future research to evaluate the pharmacological potential with detailed mechanism of actions for the pure compounds, extracts of plants from this genus. Moreover, their clinical study is needed to justify their use in modern medicine and to further exploring this genus for new drug discovery.

Promise of the NLRP3 Inflammasome Inhibitors in In Vivo Disease Models

Nucleotide-binding oligomerization domain NOD-like receptors (NLRs) are conserved cytosolic pattern recognition receptors (PRRs) that track the intracellular milieu for the existence of infection, disease-causing microbes, as well as metabolic distresses. The NLRP3 inflammasome agglomerates are consequent to sensing a wide spectrum of pathogen-associated molecular patterns (PAMPs) and danger-associated molecular patterns (DAMPs). Certain members of the NLR family have been documented to lump into multimolecular conglomerates called inflammasomes, which are inherently linked to stimulation of the cysteine protease caspase-1. Following activation, caspase-1 severs the proinflammatory cytokines interleukin (IL)-1β and IL-18 to their biologically active forms, with consequent commencement of caspase-1-associated pyroptosis. This type of cell death by pyroptosis epitomizes a leading pathway of inflammation. Accumulating scientific documentation has recorded overstimulation of NLRP3 (NOD-like receptor protein 3) inflammasome involvement in a wide array of inflammatory conditions. IL-1β is an archetypic inflammatory cytokine implicated in multiple types of inflammatory maladies. Approaches to impede IL-1β’s actions are possible, and their therapeutic effects have been clinically demonstrated; nevertheless, such strategies are associated with certain constraints. For instance, treatments that focus on systemically negating IL-1β (i.e., anakinra, rilonacept, and canakinumab) have been reported to result in an escalated peril of infections. Therefore, given the therapeutic promise of an NLRP3 inhibitor, the concerted escalated venture of the scientific sorority in the advancement of small molecules focusing on direct NLRP3 inflammasome inhibition is quite predictable.

Flavonoids as potential phytotherapeutics to combat cytokine storm in SARS-CoV-2

Emergence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection, COVID-19, has become the global panic since December 2019, which urges the global healthcare professionals to identify novel therapeutics to counteract this pandemic. So far, there is no approved treatment available to control this public health issue; however, a few antiviral agents and repurposed drugs support the patients under medical supervision by compromising their adverse effects, especially in emergency conditions. Only a few vaccines have been approved to date. In this context, several plant natural products-based research studies are evidenced to play a crucial role in immunomodulation that can prevent the chances of infection as well as combat the cytokine release storm (CRS) generated during COVID-19 infection. In this present review, we have focused on flavonoids, especially epicatechin, epigallocatechin gallate, hesperidin, naringenin, quercetin, rutin, luteolin, baicalin, diosmin, ge nistein, biochanin A, and silymarin, which can counteract the virus-mediated elevated levels of inflammatory cytokines leading to multiple organ failure. In addition, a comprehensive discussion on available in silico, in vitro, and in vivo findings with critical analysis has also been evaluated, which might pave the way for further development of phytotherapeutics to identify the potential lead candidatetoward effective and safe management of the SARS-CoV-2 disease.

Casticin Inhibits In Vivo Growth of Xenograft Tumors of Human Oral Cancer SCC-4 Cells

BACKGROUND/AIM

Casticin, one of the active components of Vitex rotundifolia L., presents biological and pharmacological activities including inhibition of migration, invasion and induction of apoptosis in numerous human cancer cells in vitro. This study aimed to assess the effects of casticin on tumor growth in a human oral cancer SCC-4 cell xenograft mouse model in vivo.

MATERIALS AND METHODS

Twenty-four nude mice were injected subcutaneously with SCC-4 cells and when palpable tumors reached a volume of 100-120 mm³ the mice were randomly divided into three groups. The control (0.1% dimethyl sulfoxide), casticin (0.2 mg/kg), and casticin (0.4 mg/kg) groups were intraperitoneally injected every two days for 18 days. Tumor volume and body weights were measured every two days.

RESULTS

Casticin significantly decreased tumor volume and weight in SCC-4 cell xenograft mice but there was no statistically significant difference between the body weights of control mice and mice treated with 0.2 mg/kg or 0.4 mg/kg casticin. Therefore, the growth of SCC-4 cells in athymic nude mice can be inhibited by casticin in vivo.

CONCLUSION

These findings support further investigations in the potential use of casticin as an oral anti-cancer drug in the future.

Casticin protected against neuronal injury and inhibited the TLR4/NF-κB pathway after middle cerebral artery occlusion in rats

Although stroke is a major human neurological disease, there is a paucity of effective neuroprotectants that can improve its treatment. Casticin is a natural monomer drug with many biological effects such as anti-inflammatory and anti-tumor actions. However, it is not clear whether it has a neuroprotective effect in ischemic stroke. In this study, the neuroprotective effect of casticin in a rat middle cerebral artery occlusion (MCAO) model was investigated. Results showed that casticin reduced the volume of the cerebral infarction, mNSS scores, swimming distance, time to find the submerged platform, and serum concentrations of TNF-α, TGF-β, IL-6 in MCAO rats. Moreover, casticin also decreased the expression of TLR4, NF-κB p65, and NF-κB p50 proteins and reversed the reduced expression of IκB protein in the brain tissue of MCAO rats. The in vitro study revealed that casticin decreased apoptosis of OGD/R-PC12 cells, reduced the expression of TLR4, NF-κB p65, and NF-κB p50, while increased IκB protein expression. In conclusion, casticin improved the neurological functions of MCAO rats via inhibiting the TLR4/NF-κB pathway and might have the potential to be developed into a neuroprotective agent for stroke patients.

Potential mechanism and key genes involved in mechanical ventilation and lipopolysaccharide‑induced acute lung injury

Mechanical ventilation (MV) and lipopolysaccharide (LPS) infection are common causes of acute lung injury. The aim of the present study was to identify the key genes and potential mechanisms involved in mechanical ventilation (MV) and lipopolysaccharide (LPS)-induced acute lung injury (ALI). Gene expression data of adult C57BL/6 mice with ALI induced by inhaling LPS, MV and LPS + MV were downloaded from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) associated with MV, LPS and LPS + MV were screened, followed by functional enrichment analysis, protein-protein interaction network construction, and prediction of transcription factors and small molecule drugs. Finally, the expression of key genes was verified in vivo using reverse transcription-quantitative PCR. A total of 63, 538 and 1,635 DEGs were associated with MV, LPS and LPS + MV, respectively. MV-associated genes were significantly enriched in the ‘purine ribonucleotide metabolic process’. LPS and LPS + MV-associated genes were significantly enriched in ‘cellular response to cytokine stimulus’ and ‘cell chemotaxis’. All three conditions were enriched in ‘TNF signaling pathway’ and ‘IL-17 signaling pathway’. Expression levels of C-X-C motif chemokine ligand (CXCL)2, CXCL3 and CXCL10 were upregulated in the LPS and LPS + MV groups. Adenosine A2b receptor, zinc finger and BTB domain-containing 16 and hydroxycarboxylic acid receptor 2 were identified as DEGs in the MV group. Compared with the control group, Early growth response 1 and activating TF 3 was upregulated in all three groups. Similarities and differences were observed among the MV- and LPS-induced ALI, and MV may enhance the effects of LPS on gene expression. MV may affect urine ribonucleotide metabolic-related processes, whereas LPS may cause cell chemotaxis and cytokine stimulus responses in ALI progression. The inflammatory response was shared by MV and LPS. The results of the present study may provide insight into a theoretical basis for the study and treatment of ALI.

MicroRNA‑93 contributes to the suppression of lung inflammatory responses in LPS‑induced acute lung injury in mice via the TLR4/MyD88/NF‑κB signaling pathway

Acute lung injury (ALI) is a severe inflammatory lung disease with a rapid onset. The anti-inflammatory functions of microRNA-93 (miRNA/miR-93) have been described in various types of tissue injury and disease. However, the biological role of miR-93 and its molecular mechanisms underlying the initiation and progression of ALI have not yet been reported, at least to the best of our knowledge. The present study aimed to investigate the regulatory effects exerted by miR-93 in ALI. Using an in vivo murine model of ALI induced by lipopolysaccharide (LPS), miR-93 expression was found to be downregulated in the lung tissues and bronchoalveolar lavage fluid (BALF) compared with the control group. Following agomiR-93 injection, it was observed that agomiR-93 attenuated lung injury, as evidenced by decreased lung permeability, a reduced lung wet/dry weight ratio and an increased survival rate of the mice. Concomitantly, agomiR-93 significantly reduced LPS-induced the interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF)-α levels in BALF. Of note, Toll-like receptor 4 (TLR4), an upstream regulator of the nuclear factor (NF)-κB signaling pathway, was directly suppressed by miR-93 in RAW 264.7 cells. Importantly, agomiR-93 induced a significant suppression of the TLR4/myeloid differentiation primary response 88 (MyD88)/NF-κB signaling pathway, as demonstrated by the downregulation of MyD88, and the phosphorylation of IκB-α and p65 in the lung tissues of mice with ALI. Taken together, the findings of the present study indicate that miR-93 attenutes LPS-induced lung injury by regulating the TLR4/MyD88/NF-κB signaling pathway, suggesting that miR-93 may prove to be a potential therapeutic target for ALI.

Fraxin Alleviates LPS-Induced ARDS by Downregulating Inflammatory Responses and Oxidative Damages and Reducing Pulmonary Vascular Permeability

Acute respiratory distress syndrome (ARDS) is a severe acute disease that threatens human health, and few drugs that can effectively treat this disease are available. Fraxin, one of the main active ingredients of Cortex Fraxini, a Chinese herbal medicine, has presented various pharmacological and biological activities. However, the effects of fraxin on ARDS have yet to be reported. In the present study, the protective effect of fraxin in lipopolysaccharide (LPS)-induced ARDS in a mouse model was analyzed. Results from the hematoxylin and eosin staining showed that fraxin might alleviate pathological changes in the lung tissues of mice with ARDS. ELISA and Western blot results revealed that fraxin might inhibit the production of inflammatory factors, namely, IL-6, TNF-α, and IL-1β, and the activation of NF-κB and MAPK signaling pathways in the lungs. Thus, the inflammatory responses were reduced. Fraxin might inhibit the increase in reactive oxygen species (ROS) and malondialdehyde (MDA), a product of lipid peroxidation in lung tissues. Fraxin might increase the superoxide dismutase (SOD) activity to avoid oxidative damage. Vascular permeability was also assessed through Evans blue dye tissue extravasation and fluorescein isothiocyanate-labeled albumin (FITC-albumin) leakage. Fraxin might inhibit the increase in pulmonary vascular permeability and relieve pulmonary edema. Fraxin was also related to the inhibition of the increase in matrix metalloproteinase-9, which is a glycocalyx-degrading enzyme, and the relief of damages to the endothelial glycocalyx. Thus, fraxin elicited protective effects on mice with LPS-induced ARDS and might be used as a drug to cure ARDS induced by Gram-negative bacterial infection.

Casticin Induces DNA Damage and Affects DNA Repair Associated Protein Expression in Human Lung Cancer A549 Cells (Running Title: Casticin Induces DNA Damage in Lung Cancer Cells)

Casticin was obtained from natural plants, and it has been shown to exert biological functions; however, no report concerns the induction of DNA damage and repair in human lung cancer cells. The objective of this study was to investigate the effects and molecular mechanism of casticin on DNA damage and repair in human lung cancer A549 cells. Cell viability was determined by flow cytometric assay. The DNA damage was evaluated by 4',6-diamidino-2-phenylindole (DAPI) staining and electrophoresis which included comet assay and DNA gel electrophoresis. The protein levels associated with DNA damage and repair were analyzed by western blotting. The expression and translocation of p-H2A.X were observed by confocal laser microscopy. Casticin reduced total viable cell number and induced DNA condensation, fragmentation, and damage in A549 cells. Furthermore, casticin increased p-ATM at 6 h and increased p-ATR and BRCA1 at 6-24 h treatment but decreased p-ATM at 24-48 h, as well as decreased p-ATR and BRCA1 at 48 h. Furthermore, casticin decreased p-p53 at 6-24 h but increased at 48 h. Casticin increased p-H2A.X and MDC1 at 6-48 h treatment. In addition, casticin increased PARP (cleavage) at 6, 24, and 48 h treatment, DNA-PKcs and MGMT at 48 h in A549 cells. Casticin induced the expressions and nuclear translocation of p-H2AX in A549 cells by confocal laser microscopy. Casticin reduced cell number through DNA damage and condensation in human lung cancer A549 cells.

Protective effects of propofol on experimental neonatal acute lung injury

The present study aimed to investigate the effects of propofol on neonatal acute lung injury (ALI) in a rat model and to examine the molecular mechanisms underlying propofol function. A rat model of ALI was established by intraperitoneal injection of lipopolysaccharides (LPS). The neonatal rats were treated with various concentrations of propofol and a lung injury score was assessed. The protein expression levels of pro‑inflammatory cytokines was detected using ELISA. In the present study, oxidative stress was determined by measuring the level of malondialdehyde (MDA) and the activity of superoxide dismutase (SOD) in lung tissues. Reverse transcription quantitative‑polymerase chain reaction and western blot analysis were used to examine the mRNA and protein expression levels of the factors downstream to LPS signaling pathway. Treatment with propofol significantly alleviated LPS‑induced lung injury in neonatal rats as suggested by the decreased lung injury score, increased partial pressure of oxygen and decreased lung wet‑dry weight ratio. LPS promoted the upregulation of tumor necrosis factor α (TNF‑α), interleukin (IL)‑6 and IL‑1β in lung tissues and bronchoalveolar lavage fluid from neonatal rats exhibiting ALI. Notably, treatment with propofol decreased the expression levels of these factors. Additionally, LPS caused an increase in the levels of MDA, and a decrease in SOD activity, and treatment with propofol suppressed these effects in a dose‑dependent manner. Furthermore, LPS induced the upregulation of phosphorylated (p‑)p38, nuclear factor κ‑light‑chain‑enhancer of activated B cells (NF‑κB), p‑p65, NLR family pyrin domain containing 3 (NLRP3), apoptosis‑associated speck‑like protein containing CARD and caspase‑1 in lung tissues of neonatal rats, and treatment with propofol was able to downregulate these factors in a dose‑dependent manner. Propofol alleviated lung injury in neonatal rats with LPS‑induced ALI by preventing inflammation and oxidative stress via the regulation of the activity of the p38 mitogen‑activated protein kinase/NF‑κB signaling pathway and the expression levels of the NLRP3 inflammasome.

Protective Effects of Casticin From Vitex trifolia Alleviate Eosinophilic Airway Inflammation and Oxidative Stress in a Murine Asthma Model

Casticin has been isolated from Vitex trifolia and found to have anti-inflammatory and anti-tumor properties. We also previously discovered that casticin can reduce pro-inflammatory cytokines and ICAM-1 expression in inflammatory pulmonary epithelial cells. In the present study, we evaluated whether casticin reduced airway hyper-responsiveness (AHR), airway inflammation, and oxidative stress in the lungs of a murine asthma model and alleviated inflammatory and oxidative responses in tracheal epithelial cells. Female BALB/c mice were randomly divided into five groups: normal controls, ovalbumin (OVA)-induced asthma, and OVA-induced asthma treated with intraperitoneal injection of casticin (5 or 10 mg/kg) or prednisolone (5 mg/kg). Casticin reduced AHR, goblet cell hyperplasia, and oxidative responses in the lungs of mice with asthma. Mechanistic studies revealed that casticin attenuated the levels of Th2 cytokine in bronchoalveolar lavage fluids and regulated the expression of Th2 cytokine and chemokine genes in the lung. Casticin also significantly regulated oxidative stress and reduced inflammation in the lungs of mice with asthma. Consequently, inflammatory tracheal epithelial BEAS-2B cells treated with casticin had significantly suppressed levels of pro-inflammatory cytokines and eotaxin, and reduced THP-1 monocyte cell adherence to BEAS-2B cells via suppressed ICAM-1 expression. Thus, casticin is a powerful immunomodulator, ameliorating pathological changes by suppressing Th2 cytokine expression in mice with asthma.

ROS Signaling in the Pathogenesis of Acute Lung Injury (ALI) and Acute Respiratory Distress Syndrome (ARDS)

The generation of reactive oxygen species (ROS) plays an important role for the maintenance of cellular processes and functions in the body. However, the excessive generation of oxygen radicals under pathological conditions such as acute lung injury (ALI) and its most severe form acute respiratory distress syndrome (ARDS) leads to increased endothelial permeability. Within this hallmark of ALI and ARDS, vascular microvessels lose their junctional integrity and show increased myosin contractions that promote the migration of polymorphonuclear leukocytes (PMNs) and the transition of solutes and fluids in the alveolar lumen. These processes all have a redox component, and this chapter focuses on the role played by ROS during the development of ALI/ARDS. We discuss the origins of ROS within the cell, cellular defense mechanisms against oxidative damage, the role of ROS in the development of endothelial permeability, and potential therapies targeted at oxidative stress.

Casticin alleviates lipopolysaccharide-induced inflammatory responses and expression of mucus and extracellular matrix in human airway epithelial cells through Nrf2/Keap1 and NF-κB pathways

Asthma is one of the most common chronic inflammatory diseases of childhood, characterized by airway inflammation, mucus hypersecretion, and accumulation of extracellular matrix proteins. Casticin is an active compound that possesses broad biological activities including anti-inflammatory effect. However, the effect of casticin on asthma remains unknown. The aim of the present study was to evaluate the effect and mechanism of casticin on inflammatory responses and expression of mucus and extracellular matrix in human airway epithelial cells. The results showed that lipopolysaccharide induced the mRNA and protein levels of IL-6, IL-8, MUC5AC, collagen type I, and fibronectin in 16-HBE cells, whereas casticin treatment significantly inhibited the induction of lipopolysaccharide. Casticin induced Nrf2/Keap1 and inhibited nuclear factor κB pathways in 16-HBE cells. Knockdown of Nrf2 attenuated the effect of casticin on production of IL-6 and IL-8, expression of MUC5AC, collagen type I, and fibronectin in 16-HBE cells. In conclusion, the results indicated that casticin might be a novel therapeutic strategy for the treatment of asthma.

Casticin from Vitex species: a short review on its anticancer and anti-inflammatory properties

This short review provides an update of the anticancer and anti-inflammatory properties of casticin from Vitex species. Casticin is a polymethylflavone with three rings, an orthocatechol moiety, a double bond, two hydroxyl groups and four methoxyl groups. Casticin has been isolated from various tissues of plants in the Vitex genus: fruits and leaves of V. trifolia, aerial parts and seeds of V. agnus-castus and leaves of V. negundo. Studies have reported the antiproliferative and apoptotic activities of casticin from Vitex species. The compound is effective against many cancer cell lines via different molecular mechanisms. Studies have also affirmed the anti-inflammatory properties of casticin, with several molecular mechanisms identified. Other pharmacological properties include anti-asthmatic, tracheospasmolytic, analgesic, antihyperprolactinemia, immunomodulatory, opioidergic, oestrogenic, anti-angiogenic, antiglioma, lung injury protection, rheumatoid arthritis amelioration and liver fibrosis attenuation activities. Clinical trials and commercial use of the casticin-rich fruit extract of V. agnus-castus among women with premenstrual syndrome were briefly discussed.

Inhibiting Inflammasomes with Small Molecules

Modulation of inflammasomes has tremendous therapeutic potential and is hotly pursued by industry and academia alike. Indeed a growing number of patents are emerging to protect the intellectual property in valuable compound classes. This chapter focusses specifically on the suite of small-molecule NLRP3 inflammasome inhibitors published, as specific modulation of other inflammasomes is not yet well established. Synthetic molecules, known drugs and natural product NLRP3 modulators will be detailed. Some of the molecular classes discussed have been extensively characterised through cell-based screening, pharmacokinetic profiling and therapeutic proof of concept animal models. However, many inhibitors lack rigorous studies and/or have multiple activities of which NLRP3 modulation is only one. While this is not intended as an exhaustive list, it should give an impression of the range of structures and strategies that are being used, alongside challenges encountered, in an effort to exploit the significant therapeutic benefits of targeting inflammasomes.