Idebenone Protects against Acute Murine Colitis via Antioxidant and Anti-Inflammatory Mechanisms

Hypoxia-associated autophagy flux dysregulation in human cancers

A general feature of cancer is hypoxia, determined as low oxygen levels. Low oxygen levels may cause cells to alter in ways that contribute to tumor growth and resistance to treatment. Hypoxia leads to variations in cancer cell metabolism, angiogenesis and metastasis. Furthermore, a hypoxic tumor microenvironment might induce immunosuppression. Moreover, hypoxia has the potential to impact cellular processes, such as autophagy. Autophagy refers to the catabolic process by which damaged organelles and toxic macromolecules are broken down. The abnormal activation of autophagy has been extensively recorded in human tumors and it serves as a regulator of cell growth, spread to other parts of the body, and resistance to treatment. There is a correlation between hypoxia and autophagy in human malignancies. Hypoxia can regulate the activity of AMPK, mTOR, Beclin-1, and ATGs to govern autophagy in human malignancies. Furthermore, HIF-1α, serving as an indicator of low oxygen levels, controls the process of autophagy. Hypoxia-induced autophagy has a crucial role in regulating the growth, spread, and resistance to treatment in human malignancies. Hypoxia-induced regulation of autophagy can impact other mechanisms of cell death, such as apoptosis. Chemoresistance and radioresistance have become significant challenges in recent years. Hypoxia-mediated autophagy plays a crucial role in determining the response to these therapeutic treatments.

Coenzyme Q10 and Autoimmune Disorders: An Overview

Some 90 autoimmune disorders have been described in medical literature, affecting most of the tissues within the body. Autoimmune disorders may be difficult to treat, and there is a need to develop novel therapeutic strategies for these disorders. Autoimmune disorders are characterised by mitochondrial dysfunction, oxidative stress, and inflammation; there is therefore a rationale for a role for coenzyme Q10 in the management of these disorders, on the basis of its key role in normal mitochondrial function, as an antioxidant, and as an anti-inflammatory agent. In this article, we have therefore reviewed the potential role of CoQ10, in terms of both deficiency and/or supplementation, in a range of autoimmune disorders.

Anti-Inflammatory Effects of Idebenone Attenuate LPS-Induced Systemic Inflammatory Diseases by Suppressing NF-κB Activation

Inflammation is a natural protective process through which the immune system responds to injury, infection, or irritation. However, hyperinflammation or long-term inflammatory responses can cause various inflammatory diseases. Although idebenone was initially developed for the treatment of cognitive impairment and dementia, it is currently used to treat various diseases. However, its anti-inflammatory effects and regulatory functions in inflammatory diseases are yet to be elucidated. Therefore, this study aimed to investigate the anti-inflammatory effects of idebenone in cecal ligation puncture-induced sepsis and lipopolysaccharide-induced systemic inflammation. Murine models of cecal ligation puncture-induced sepsis and lipopolysaccharide-induced systemic inflammation were generated, followed by treatment with various concentrations of idebenone. Additionally, lipopolysaccharide-stimulated macrophages were treated with idebenone to elucidate its anti-inflammatory effects at the cellular level. Idebenone treatment significantly improved survival rate, protected against tissue damage, and decreased the expression of inflammatory enzymes and cytokines in mice models of sepsis and systemic inflammation. Additionally, idebenone treatment suppressed inflammatory responses in macrophages, inhibited the NF-κB signaling pathway, reduced reactive oxygen species and lipid peroxidation, and normalized the activities of antioxidant enzyme. Idebenone possesses potential therapeutic application as a novel anti-inflammatory agent in systemic inflammatory diseases and sepsis.

The protective effect of Schisandra chinensis (Turcz.) Baill. polysaccharide on DSS-induced ulcerative colitis in mice via the modulation of gut microbiota and inhibition of NF-κB activation

BACKGROUND

Schisandra chinensis (Turcz.) Baill, a fruit utilized in traditional Chinese medicine (TCM), has a long history of medical application. It has been used to treat diseases of the gastrointestinal tract. Schisandra chinensis (Turcz.) Baill polysaccharide (SACP) is an important biologically active ingredient that has been shown to have a variety of beneficial effects including immune regulation and anti-oxidative properties. Ulcerative colitis (UC) is a complicated gastrointestinal inflammatory disease. We explore the protective effect of SACP against UC.

RESULTS

Schisandra chinensis (Turcz.) Baill polysaccharide significantly reduced the disease activity index (DAI) and levels of myeloperoxidase(MPO) and malondialdehyde (MDA) in colonic tissue. It also alleviated weight loss and histopathological damage of mice. The expression of MUC2 and occludin proteins was increased and the barrier function of the colonic mucosa was enhanced by SACP treatment. NF-κB pathway activation was also inhibited and the production of pro-inflammatory cytokines was decreased whereas anti-inflammatory cytokines were increased. 16SrDNA sequencing of fecal flora showed that SACP increased the abundance of Muribaculaceaeunclassified, LachnospiraceaeNK4A136group and reduced the abundance of Bacteroides and Erysipelatoclostridium.

CONCLUSION

Schisandra chinensis (Turcz.) Baill polysaccharide can protect against Dextran Sulfate Sodium Salt (DSS)-induced ulcerative colitis in mice. © 2023 Society of Chemical Industry.

Daphnetin attenuates intestinal inflammation, oxidative stress, and apoptosis in ulcerative colitis via inhibiting REG3A-dependent JAK2/STAT3 signaling pathway

Daphnetin is a natural coumarin compound with anti-inflammatory, anti-oxidant, and anti-apoptotic effects, which has been previously demonstrated to ameliorate DSS-induced ulcerative colitis (UC). However, the molecular mechanism involved in the daphnetin-mediated pathological process of UC remains unclarified. The current study used DSS-induced mice and LPS-challenged Caco-2 cells as UC models. Bodyweight, disease activity index (DAI) score, and colon length were used to evaluate the severity of colitis. The histological changes in colon tissues were observed using H&E and PAS staining. Protein levels were detected by western blot. The malondialdehyde (MDA) and superoxide dismutase (SOD) activities were used to assess oxidative stress. Inflammatory responses were evaluated by detecting the levels of inflammatory cytokines (IFN-r, IL-1β, IL-6, and TNF-α) using flow cytometry. CCK-8 and TUNEL assay were employed to determine cell growth and cell death, respectively. The results showed that daphnetin could ameliorate the severity of colitis and attenuate the damage to intestinal structure in DSS-induced mice. Compared with the DSS group, the expression of ZO-1, occludin, and anti-apoptotic protein (BCL-2) was increased while the level of pro-apoptotic proteins (Bax and cleaved caspase 3) was decreased in DSS + daphnetin group. The activity of MDA and SOD, as well as the levels of inflammatory cytokines were substantially suppressed by daphnetin. In consistency, in vitro assays indicated that daphnetin protected Caco-2 cells from LPS-stimulated viability impairment, apoptosis, oxidative stress, and inflammation. Furthermore, daphnetin suppressed the activity of JAK2/STAT signaling in LPS-induced Caco-2 cells in a REG3A-dependent manner. REG3A overexpression abated the ameliorative effects of daphnetin while JAK2/STAT signaling inhibition functioned synergically with daphnetin in LPS-stimulated Caco-2 cells. Collectively, this study deepened the understanding of the therapeutic effects of daphnetin on UC and uncovered for the first time that daphnetin functioned through REG3A-activated JAK2/STAT3 signaling in UC, which may provide novel insights for the treatment of UC.

Paris polyphylla extract attenuates colitis in mice by regulating PPAR-γ mediated Treg/Th17 balance

ETHNOPHARMACOLOGICAL RELEVANCE

Paris polyphylla Sm. (P.P), is a widely-used traditional Chinese medicine (TCM) in the treatment of wound, throat sores and snakebites. Furthermore, P.P was recorded as an anti-inflammatory drug by the Chinese Pharmacopoeia.

AIM OF THE STUDY

We sought to decipher the anti-inflammatory effect of P.P on ulcerative colitis (UC); specifically, to explore whether P.P attenuates colitis by restoring the regulatory T cells (Tregs) and T helper 17 (Th17) cells balance and its mechanism.

MATERIAL AND METHODS

We treated experimental colitis mice with extracts of Paris polyphylla (EPP). The percentage of Tregs and Th17 cells were measured using flow cytometry, and their secreted cytokines levels were evaluated employing ELISA. The expression of peroxisome proliferator-activated receptor gamma (PPAR-γ) in colon tissues was detected using immunofluorescence. Furthermore, GW9662, a PPAR-γ antagonist, was used to validate the mechanism of EPP in restoring the Treg/Th17 balance.

RESULTS

The EPP effectively alleviated the clinical symptoms and inflammatory cytokine levels in mice with colitis. EPP treatment also restored the impaired Treg/Th17 balance in mice. Furthermore, EPP treatment promoted PPAR-γ expression and reduced HIF-1α and p-STAT3 expression in colon tissues, whereas PPAR-γ inhibition blocked the effects of EPP in mice models.

CONCLUSION

Our study indicates that EPP exhibit excellent anti-inflammatory properties via restoring PPAR-γ/STAT3/HIF-1α axis-mediated Treg/Th17 balance in colitis mice. Hence, P. polyphylla is a promising medicinal plant-based alternative for managing colitis that requires further clinical validation.

Idebenone attenuates ferroptosis by inhibiting excessive autophagy via the ROS-AMPK-mTOR pathway to preserve cardiac function after myocardial infarction

Cardiovascular diseases (CVDs) are the leading causes of mortality worldwide. As a type of CVDs, myocardial infarction (MI) induces ischemia hypoxia, which leads to excessive reactive oxygen species (ROS), resulting in multiple cell deaths and contributing to the subsequent development of heart failure or premature death. Recent evidence indicates that ROS-induced lipid peroxidation promotes autophagy and ferroptosis, leading to the loss of healthy myocardium and resulting in the dysfunction of cardiac tissue. Theoretically, cardiac function would be preserved after MI by inhibiting autophagy and ferroptosis. As an analog of coenzyme Q10 (CoQ10) and a clinically approved drug, idebenone would be used to inhibit ferroptosis and preserve cardiac function due to its capacity to improve mitochondrial physiology with antioxidant and anti-inflammatory properties. Here, we confirmed that the addition of idebenone inhibited H₂O₂-induced and RSL3-induced ferroptosis. Furthermore, the ROS-AMPK-mTOR pathway axis was identified as the signaling pathway that idebenone stimulated to prevent excessive autophagy and consequent ferroptosis. In the MI animal model, idebenone demonstrated a cardioprotective role by regulating ROS-dependent autophagy and inhibiting ferroptosis, which paves the way for the future clinical translation of idebenone in MI management.

Theabrownin from Fu Brick Tea Improves Ulcerative Colitis by Shaping the Gut Microbiota and Modulating the Tryptophan Metabolism

Fu brick tea theabrownin (FBTB) is a kind of biomacromolecule produced by oxidative polymerization of tea polyphenols. Although a variety of diseases can be alleviated by TB, its ability to treat ulcerative colitis (UC) is still worth exploring. A dextran sulfate sodium (DSS)-induced chronic UC mouse model was designed to first explore the alleviatory effect of FBTB on UC and its underlying mechanism by the sequencing of fecal 16S rRNA genes, metabolomics, and fecal microbiota transplantation (FMT). Administration of FBTB at 400 mg/kg bw in DSS-damaged mice could effectively reduce colonic damage and inflammation and improve colonic antioxidant capacity to relieve the UC-caused symptoms. FBTB could correct the disrupted gut microbiota caused by UC and contribute to the proliferation of Lactobacillus and Parasutterella. FMT in combination with antibiotic treatment showed that FBTB could elevate the levels of microbial tryptophan metabolites, including indole-3-acetaldehyde (IAld) and indole-3-acetic acid (IAA), by selectively promoting the growth of Lactobacillus. Importantly, FBTB-elevated IAld and IAA could activate aromatic hydrocarbon receptors (AhRs) and enhance interleukin-22 production to repair the intestinal barrier. These findings demonstrated that FBTB alleviated UC mainly by targeting the gut microbiota involved in the AhR pathway for prophylactic and therapeutic treatment of UC.

Protection of dystrophic muscle cells using Idebenone correlates with the interplay between calcium, oxidative stress and inflammation

There is strong cross-talk between abnormal intracellular calcium concentration, high levels of reactive oxygen species (ROS) and an exacerbated inflammatory process in the dystrophic muscles of mdx mice, the experimental model of Duchenne muscular dystrophy (DMD). In this study, we investigated effects of Idebenone, a potent anti-oxidant, on oxidative stress markers, the anti-oxidant defence system, intracellular calcium concentrations and the inflammatory process in primary dystrophic muscle cells from mdx mice. Dystrophic muscle cells were treated with Idebenone (0.05 μM) for 24 h. The untreated mdx muscle cells were used as controls. The MTT assay showed that Idebenone did not have a cytotoxic effect on the dystrophic muscle cells. The Idebenone treatment was able to reduce the levels of oxidative stress markers, such as H2 O2 and 4-HNE, as well as decreasing intracellular calcium influx in the dystrophic muscle cells. Regarding Idebenone effects on the anti-oxidant defence system, an up-regulation of catalase levels, glutathione reductase (GR), glutathione peroxidase (GPx) and superoxide dismutase (SOD) activity was observed in the dystrophic muscle cells. In addition, the Idebenone treatment was also associated with reduction in inflammatory molecules, such as nuclear factor kappa-B (NF-κB) and tumour necrosis factor (TNF) in mdx muscle cells. These outcomes supported the use of Idebenone as a protective agent against oxidative stress and related signalling mechanisms involved in dystrophinopathies, such as DMD.

Impact of Plasticizer on the Intestinal Epithelial Integrity and Tissue-Repairing Ability within Cells in the Proximity of the Human Gut Microbiome

Toxicological research into the impact of plasticizer on different organs has been reported in the past few decades, while their effects on shifting the gut microbiota and immune cells homeostasis in zebrafish were only studied recently. However, studies on the impact of plasticizer on human gut microbiota are scarce. In this study, we co-incubated healthy human fecal microbiota with different concentrations of Di(2-ethylhexyl) phthalate (DEHP) and di-iso-nonyl phthalate (DINP), analyzed microbial composition by 16S rDNA sequencing, and compared the influence of their derived microbiomes on the human enterocyte (HT-29) and murine macrophage (RAW264.7) cell lines. Microbial diversity is reduced by DEHP treatment in a dose-dependent manner. DEHP treatment reduced the phyla Firmicutes/Bacteroidetes ratio, while DINP treatment promoted Proteobacteria. Expressions of tight/adherens junction genes in HT-29 and anti-inflammatory genes in RAW264.7 were down-regulated by plasticizer-co-incubated microbiota derived metabolites. Overall, it is observed that selected plasticizers at high dosages can induce compositional changes in human microbiota. Metabolites from such altered microbiota could affect the tight junction integrity of the intestinal epithelium and upset macrophage differentiation homeostasis in proximity. Chronic exposure to these plasticizers may promote risks of dysbiosis, leaky gut or the exacerbation of intestinal inflammation.

Idebenone-loaded wound dressings promote diabetic wound healing through downregulation of Il1b, Nfkb genes and upregulation of Fgf2 gene

Reactive oxygen species (ROS) are overproduced in diabetic wounds and retard the healing response. Considering the antioxidative function of idebenone, its exogenous administration may quench excessive ROS and promote diabetic wound healing. In the current study, idebenone was loaded into polyvinyl alcohol (PVA) /calcium alginate scaffolds at three different concentrations of 1 w/w%, 2 w/w%, and 3 w/w%. Various in vitro experiments were performed to characterize the developed wound dressings. Cell viability assay showed that scaffolds loaded with 1 w/w% idebenone had significantly better protection under oxidative stress and exhibited higher cell viability. Therefore, the dressings containing 1% drug was chosen to treat diabetic wounds in rat model. Wound healing assay showed that the dressings loaded with 1% drug had significantly higher rate of wound size reduction, collagen deposition, and epithelial thickness. Gene expression study showed that wound healing was accompanied by modulation of inflammatory response, protection against oxidative stress, and increasing angiogenesis-related genes. This preliminary research suggests that PVA/calcium alginate/1% idebenone scaffolds can be considered as a potential treatment modality to treat diabetic wounds in the clinic. However, more extensive studies at gene and protein expression levels are required to understand its exact mechanism of healing effects.

Potential mechanisms of Lian-Zhi-Fan solution for TNBS-induced ulcerative colitis in rats via a metabolomics approach

Lian-Zhi-Fan (LZF) decoction is a hospital-prescribed traditional Chinese medicine botanical drug prepared by the fermentation of decocted Coptidis Rhizome (Huanglian), Gardeniae Fructus (Zhizi), and alum (Baifan). It has been used clinically in China for the treatment of anal fistula, perianal abscess, ulcerative colitis (UC), and other anorectal diseases for hundreds of years. However, due to the complexity of traditional Chinese medicine, the potential mechanisms of LZF in the treatment of UC have remained unknown. This study primarily investigated the remarkable pharmacological effects of LZF on TNBS-induced UC rats. To explore the complex targets and regulatory mechanisms of metabolic networks under LZF intervention, a metabolomics approach mediated by HPLC/Q-TOF-MS analysis was used to screen the different metabolites and their metabolic pathways in the serum in order to characterize the possible anti-UC mechanisms of LZF. After rectal administration of LZF for seven consecutive days, significant amelioration effects on body weight loss, DAI score, and colon inflammation were found in UC rats. Based on this, further metabolomics identified 14 potential biomarkers in the treatment of UC with LZF, of which five possessed diagnostic significance: L-alanine, taurocholic acid, niacinamide, cholic acid, and L-valine. These metabolites are mainly involved in 12 metabolic pathways, including nicotate and nicotinamide metabolism, glycospholipid metabolism, arginine and proline metabolism, primary bile acid biosynthesis, and pantothenate and CoA biosynthesis. These metabolic pathways suggest that LZF ameliorates UC by regulating amino acid metabolism, fat metabolism, and energy production. This study provides a useful approach for exploring the potential mechanisms of herbal prescription in UC treatment mediated by metabolomics.

Network pharmacology and in vivo experiment-based strategy to investigate mechanisms of JingFangFuZiLiZhong formula for ulcerative colitis

BACKGROUND

Ulcerative colitis (UC), a chronic inflammatory disease, often cause carcinogenesis, disability, and intestinal perforation. The JingFangFuZiLiZhong formula (JFFZLZ) shows a good effect against UC in the clinic. Hence, we aim to investigate the mechanisms between JFFZLZ and UC via network pharmacology data mining and in vivo experiments.

METHODS

We obtained active constituents and related targets from public databases. The overlapped genes between JFFZLZ and UC targets were further analysed by enrichment analysis. The active constituents and hub targets were used to construct molecule docking analysis. We finally screened out nine hub targets and their expressions were verified in the Gene Expression Omnibus database and UC rats' colon tissues after JFFZLZ treatment.

RESULTS

The results implied that JFFZLZ mainly regulated signal transduction, metabolites production, and inflammation pathways. The expression of STAT3, CXCL8, IL6, CXCL12, TNF, TP53, and PTPN11 were both upregulated in colon tissues of UC patients and UC rats. While RELA, EGFR, and TP53 were downregulated in UC patients, but upregulated in UC rats. Furthermore, JFFZLZ could repair UC rats' colon mucosal damage and promote the healing of ulcers via regulating the hub targets.

CONCLUSION

These results elucidated that the anti-UC effect of JFFZLZ was closely related to the inhibition of inflammatory response, inhibition of oxidative stress, and repairing colon mucosal damage through different signal pathways. The findings could contribute to a better understanding of the regulation mechanisms in JFFZLZ against UC.Key messagesJFFZLZ could reduce the inflammatory infiltration and repair UC rats' colon mucosal damage.Through the network pharmacology-based strategy and public database mining, we obtained the hub targets and key pathways between JFFZLF and UC.The mechanism of JFFZLZ against UC was inhibition of inflammatory response and oxidative stress by regulating the expression of the hub targets.

Oral Macrocystis pyrifera Fucoidan Administration Exhibits Anti-Inflammatory and Antioxidant Properties and Improves DSS-Induced Colitis in C57BL/6J Mice

Inflammatory bowel disease (IBD) is a complex and multifactorial disorder characterised by relapsing and remitting inflammation of the intestinal tract. Oxidative stress (OS) is the result of an imbalance between production and accumulation of reactive oxygen species (ROS), which has been associated with inflammatory responses and implicated in the exacerbation of IBD. Fucoidan, a sulfated polysaccharide from brown seaweed, is a well-known anti-inflammatory agent and emerging evidence indicates that fucoidan extracts from Macrocystis pyrifera (MPF and DP-MPF) may also modulate oxidative stress. This study investigated the impact of fucoidan extracts, MPF and DP-MPF in a dextran sodium sulphate (DSS)-induced mouse model of acute colitis. 3% DSS was administered in C57BL/6J male mice over a period of 7 days, and MPF and DP-MPF were co-administered orally at a dose of 400 mg/kg body weight. Our results indicated that MPF and DP-MPF significantly prevented body weight loss, improved the disease activity index (DAI), restored colon lengths, reduced the wet colon weight, reduced spleen enlargement, and improved the overall histopathological score. Consistent with the reported anti-inflammatory functions, fucoidan extracts, MPF and DP-MPF significantly reduced the colonic levels of myeloperoxidase (MPO), nitric oxide (NO), malondialdehyde (MDA) and increased the levels of antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT). In addition, MPF and DP-MPF significantly inhibited levels of pro-inflammatory cytokines in colon-derived tissues. Collectively, our results indicate that MPF and DP-MPF exhibited anti-inflammatory and antioxidant effects representing a promising therapeutic strategy for the cure of IBD.

Protective effect of traditional Korean fermented soybean foods (doenjang) on a dextran sulfate sodium-induced colitis mouse model

Objective: The cause of ulcerative colitis (UC) is unknown, and the use of anti-inflammatory and immunosuppressive drugs with certain side effects is currently replacing treatment. Therefore, it is important to find new healthy foods or ingredients that exhibit potential protective and anti-inflammatory effects on UC. This study investigated the potential protective effect of doenjang on dextran sulfate sodium (DSS)-induced colitis in a mouse model. Materials and methods: Four doenjang samples (TCD21-51-1, TCD21-55-1, TMD21-16-1, and TFD21-1-1) were used. To examine the effects of the four doenjang samples on UC caused by DSS in a mouse model, the clinical symptoms of UC, such as body weight, disease activity index (DAI), and colon macroscopic damage index (CMDI) were analyzed. Moreover, immune-related blood cell counts, serum levels and protein expression of tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6), and nitric oxide (NO) production were measured in DSS-induced UC in mice for analysis. Results: The four doenjang samples increased the colon length shortened by DSS, reduced DAI (diarrhea and hemoccult), CMDI (ulceration, inflammation, and hemorrhage) and the content of immune-related cells in the blood. Moreover, the levels of TNF-α, IL-6, and NO increased by DSS were decreased by doenjang, and tissue damage was significantly reduced. Conclusions: These findings confirmed that doenjang exerts protective effects against UC, suggesting its possible use in developing therapeutic strategies or functional products.

Antioxidant Activity of Acanthopanax senticosus Flavonoids in H2O2-Induced RAW 264.7 Cells and DSS-Induced Colitis in Mice

The redox reaction is a normal process of biological metabolism in the body that leads to the production of free radicals. Under conditions such as pathogenic infection, stress, and drug exposure, free radicals can exceed normal levels, causing protein denaturation, DNA damage, and the oxidation of the cell membrane, which, in turn, causes inflammation. Acanthopanax senticosus (A. senticosus) flavonoids are the main bioactive ingredients with antioxidant function. H₂O₂-treated RAW 264.7 cells and DSS-induced colitis in mice were used to evaluate the antioxidant properties of A. senticosus flavonoids. The results show that A. senticosus flavonoids can significantly downregulate the levels of ROS and MDA in H₂O₂-treated RAW 264.7 cells and increase the levels of CAT, SOD, and GPx. A. senticosus flavonoids can also increase the body weights of DSS-induced colitis mice, increase the DAI index, and ameliorate the shortening of the colon. ELISA experiments confirmed that A. senticosus flavonoids could reduce the level of MDA in the mouse serum and increase the levels of SOD, CAT, and GPx. Histopathology showed that the tissue pathological changes in the A. senticosus flavonoid group were significantly lower than those in the DSS group. The Western blot experiments showed that the antioxidant capacity of A. senticosus flavonoids was accomplished through the Nrf2 pathway. In conclusion, A. senticosus flavonoids can relieve oxidative stress in vivo and in vitro and protect cells or tissues from oxidative damage.

Aconitate Decarboxylase 1 Deficiency Exacerbates Mouse Colitis Induced by Dextran Sodium Sulfate

Ulcerative colitis is a complex inflammatory bowel disorder disease that can induce rectal and colonic dysfunction. Although the prevalence of IBD in Western countries is almost 0.5% of the general population, genetic causes are still not fully understood. In a recent discovery, itaconate was found to function as an immune-modulating metabolite in mammalian immune cells, wherein it is synthesized as an antimicrobial compound from the citric acid cycle intermediate cis-aconitic acid. However, the association between the Acod1 (Aconitate decarboxylase 1)-itaconate axis and ulcerative colitis has rarely been studied. To elucidate this, we established a DSS-induced colitis model with Acod1-deficient mice and then measured the mouse body weights, colon lengths, histological changes, and cytokines/chemokines in the colon. We first confirmed the upregulation of Acod1 RNA and protein expression levels in DSS-induced colitis. Then, we found that colitis symptoms, including weight loss, the disease activity index, and colon shortening, were worsened by the depletion of Acod1. In addition, the extent of intestinal epithelial barrier breakdown, the extent of immune cell infiltration, and the expression of proinflammatory cytokines and chemokines in Acod1-deficient mice were higher than those in wild-type mice. Finally, we confirmed that 4-octyl itaconate (4-OI) alleviated DSS-induced colitis in Acod1-deficient mice and decreased the expression of inflammatory cytokines and chemokines. To our knowledge, this study is the first to elucidate the role of the Acod1-itaconate axis in colitis. Our data clearly showed that Acod1 deletion resulted in severe DSS-induced colitis and substantial increases in inflammatory cytokine and chemokine levels. Our results suggest that Acod1 may normally play an important regulatory role in the pathogenesis of colitis, demonstrating the potential for novel therapies using 4-OI.

Idebenone Regulates Aβ and LPS-Induced Neurogliosis and Cognitive Function Through Inhibition of NLRP3 Inflammasome/IL-1β Axis Activation

Idebenone is an analogue of coenzyme Q10, an electron donor in the mitochondrial electron transport chain, and thus may function as an antioxidant to facilitate mitochondrial function. However, whether idebenone modulates LPS- and Aβ-mediated neuroinflammatory responses and cognitive function in vivo is unknown. The present study explored the effects of idebenone on LPS- or Aβ-mediated neuroinflammation, learning and memory and the underlying molecular mechanisms in wild-type (WT) mice and 5xFAD mice, a mouse model of Alzheimer’s disease (AD). In male and female WT mice, idebenone upregulated neuroprotective NRF2 expression, rescued LPS-induced spatial and recognition memory impairments, and reduced NLRP3 priming and subsequent neuroinflammation. Moreover, idebenone downregulated LPS-mediated neurogliosis, reactive oxygen species (ROS) levels, and mitochondrial function in BV2 microglial cells and primary astrocytes by inhibiting NLRP3 inflammasome activation. In 5xFAD mice, idebenone increased neuroprotective NRF2 expression and improved amyloid beta (Aβ)-induced cognitive dysfunction. Idebenone downregulated Aβ-mediated gliosis and proinflammatory cytokine levels in 5xFAD mice by modulating the vicious NLRP3/caspase-1/IL-1β neuroinflammation cycle. Taken together, our results suggest that idebenone targets neuroglial NLRP3 inflammasome activation and therefore may have neuroprotective effects and inhibit the pathological progression of neuroinflammation-related diseases.

Idebenone regulates sirt1/Nrf2/TNF-α pathway with inhibition of oxidative stress, inflammation, and apoptosis in testicular torsion/detorsion in juvenile rats

Testicular torsion is an emergency, mainly in newborn and adolescent males, resulting in testicular ischemia. The current study aimed to evaluate the effect of Idebenone (IDE) on testicular torsion/detorsion (T/D) in juvenile rats. Thirty-two rats were randomized into: (1) the sham group: rats received sham operations with no other interventions; (2) the IDE group: rats received idebenone (100 mg/kg, i. p) without T/D; (3) the T/D group: rats underwent torsion for 2 h and detorsion for 4 h; and (4) the IDE+ T/D group: rats received IDE 1 h before T/D. Testicular malondialdehyde (MDA), total nitrite/nitrate (NOx), total antioxidant capacity (TAC), tumor necrosis factor-α (TNF-α), caspase-3, sirtuin type 1 (Sirt1), serum interleukin-1β (IL-1β), total cholesterol, and testosterone were measured. Histological changes, nuclear factor (erythroid-derived 2)-like-2 factors (Nrf2), and proliferating cell nuclear antigen (PCNA) immuno-expressions were assessed. T/D displayed an increase in MDA, NOx, TNF-α, caspase-3, IL-1β, and total cholesterol with a significant decrease in TAC, Sirt1, and testosterone and strong positive Nrf2 and negative PCNA immuno-expressions. IDE could improve all oxidative, inflammatory, and apoptotic indicators. Therefore, IDE significantly reduced testicular ischemia-reperfusion injury in the juvenile rat testicular T/D model by limiting oxidative stress, inflammation, and apoptosis via the Sirt1/Nrf2/TNF-α pathway.

Licoflavone B, an isoprene flavonoid derived from licorice residue, relieves dextran sodium sulfate-induced ulcerative colitis by rebuilding the gut barrier and regulating intestinal microflora

Ulcerative colitis (UC) is a major inflammatory disease worldwide. We previously demonstrated that licorice residue flavones (LFs) showed satisfactory efficacy in the treatment of UC. Therefore, research into the ingredients of LFs may lead to the discovery of novel anti-UC targets. In the current study, we separated licoflavone B (LB) from LFs and administered it to dextran sodium sulfate (DSS)-exposed C57BL/6 mice for 14 days. Our results demonstrated that high dose LB (120mg/kg) significantly prevented DSS-induced weight loss, disease activity index (DAI) increase, histological damage, and colonic inflammation, indicating that LB has ameliorative effects on UC. We also investigated the composition of the intestinal barrier and microflora in an attempt to explore the mechanisms of LB against UC. As a result, we found that LB preserved the integrity of the colonic barrier by inhibiting colonic cell apoptosis and protecting the expression of occludin, claudin-1, and ZO-1. Moreover, LB reshaped the microflora composition by suppressing harmful bacteria (Enterococcus et al.) and boosting beneficial microorganisms (Bacteroides et al.). Further molecular exploration implied that LB exerted anti-UC activity through blocking the MAPK pathway. Here, we explored anti-UC activity of LB for the first time and clarified its mechanisms. These results will provide valuable clues for the discovery of novel anti-UC agents.

SHARP hydrogel for the treatment of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a relapsing and remitting inflammatory disease affecting millions of people worldwide. The active phase of IBD is characterized by excessive formation of reactive oxygen species (ROS) in the intestinal mucosa, which further accelerates the inflammatory process. A feasible strategy for the IBD treatment is thus breaking the oxidation-inflammation vicious circle by scavenging excessive ROS with the use of a suitable antioxidant. Herein, we have developed a novel hydrogel system for oral administration utilizing sterically hindered amine-based redox polymer (SHARP) incorporating covalently bound antioxidant SHA groups. SHARP was prepared via free-radical polymerization by covalent crosslinking of 2-hydroxyethyl methacrylate (HEMA), poly(ethylene oxide) methyl ether methacrylate (PEGMA) and a SHA-based monomer, N-(2,2,6,6-tetramethyl-piperidin-4-yl)-methacrylamide. The SHARP hydrogel was resistant to hydrolysis and swelled considerably (∼90% water content) under the simulated gastrointestinal tract (GIT) conditions, and exhibited concentration-dependent antioxidant properties in vitro against different ROS. Further, the SHARP hydrogel was found to be non-genotoxic, non-cytotoxic, non-irritating, and non-absorbable from the gastrointestinal tract. Most importantly, SHARP hydrogel exhibited a statistically significant, dose-dependent therapeutic effect in the mice model of dextran sodium sulfate (DSS)-induced acute colitis. Altogether, the obtained results suggest that the SHARP hydrogel strategy holds a great promise with respect to IBD treatment.

Fermented rice bran supplementation attenuates chronic colitis-associated extraintestinal manifestations in female C57BL/6N mice

Patients with inflammatory bowel disease (IBD) have higher incidence of extraintestinal manifestations (EIM), including liver disorders, sarcopenia, and neuroinflammation. Fermented rice bran (FRB), generated from rice bran (RB), is rich in bioactive compounds, and exhibits anti-colitis activity. However, its role in EIM prevention is still unclear. Here, for the first time, we investigated whether EIM in female C57Bl/6N mice is attenuated by FRB supplementation. EIM was induced by repeated administration of 1.5% dextran sulfate sodium (DSS) in drinking water (4 d) followed by drinking water (12 d). Mice were divided into 3 groups-control (AIN93M), 10% RB, and 10% FRB. FRB ameliorated relapsing colitis and inflammation in muscle by significantly lowering proinflammatory cytokines Tnf-α and Il-6 in serum and advanced glycation end product-specific receptor (Ager) in serum and muscle when compared with the RB and control groups. As FRB reduced aspartate aminotransferase levels and oxidative stress, it might prevent liver disorders. FRB downregulated proinflammatory cytokine and chemokine transcripts responsible for neuroinflammation in the hippocampus and upregulated mRNA expression of G protein coupled receptors (GPRs), Gpr41 and Gpr43, in small and large intestines, which may explain the FRB-mediated protective mechanism. Hence, FRB can be used as a supplement to prevent IBD-associated EIM.

Short-Chain Naphthoquinone Protects Against Both Acute and Spontaneous Chronic Murine Colitis by Alleviating Inflammatory Responses

Ulcerative colitis (UC) is characterised by chronic, relapsing, idiopathic, and multifactorial colon inflammation. Recent evidence suggests that mitochondrial dysfunction plays a critical role in the onset and recurrence of this disease. Previous reports highlighted the potential of short-chain quinones (SCQs) for the treatment of mitochondrial dysfunction due to their reversible redox characteristics. We hypothesised that a recently described potent mitoprotective SCQ (UTA77) could ameliorate UC symptoms and pathology. In a dextran sodium sulphate- (DSS-) induced acute colitis model in C57BL/6J mice, UTA77 substantially improved DSS-induced body weight loss, disease activity index (DAI), colon length, and histopathology. UTA77 administration also significantly increased the expression of tight junction (TJ) proteins occludin and zona-occludin 1 (ZO-1), which preserved intestinal barrier integrity. Similar responses were observed in the spontaneous Winnie model of chronic colitis, where UTA77 significantly improved DAI, colon length, and histopathology. Furthermore, UTA77 potently suppressed elevated levels of proinflammatory cytokines and chemokines in colonic explants of both DSS-treated and Winnie mice. These results strongly suggest that UTA77 or its derivatives could be a promising novel therapeutic approach for the treatment of human UC.

The Regulatory Effects of Licochalcone A on the Intestinal Epithelium and Gut Microbiota in Murine Colitis

The gut epithelium is a mechanical barrier that protects the host from the luminal microenvironment and interacts with the gut microflora, which influences the development and progression of ulcerative colitis (UC). Licochalcone A (LA) exerts anti-inflammatory effects against UC; however, whether it also regulates both the gut barrier and microbiota during colitis is unknown. The current study was conducted to reveal the regulatory effects of LA on the intestinal epithelium and gut microflora in C57BL/6 mice subjected to dextran sodium sulfate (DSS). Sulfasalazine (SASP) was used as the positive control. Results of clinical symptoms evaluation, hematoxylin, and eosin (H&E) staining, and enzyme-linked immunosorbent (ELISA) assays showed that LA significantly inhibited DSS-induced weight loss, disease activity index (DAI) increase, histological damage, and gut inflammation. Additionally, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and immunohistochemical (IHC) analysis showed that LA maintained the integrity of the intestinal barrier by suppressing cell apoptosis and preserving the expression of tight junction (TJ) proteins. Notably, the optimal dose of LA for gut barrier preservation was low, while that for anti-inflammatory effects was high, indicating that LA might preserve gut barrier integrity via direct effects on the epithelial cells (ECs) and TJ proteins. Furthermore, 16S rRNA analysis suggested that the regulatory effect of LA on the gut microbiota differed distinctly according to dose. Correlation analysis indicated that a low dose of LA significantly modulated the intestinal barrier-associated bacteria as compared with a moderate or high dose of LA. Western blot (WB) analysis indicated that LA exhibited anti-UC activity partly by blocking the mitogen-activated protein kinase (MAPK) pathway. Our results further elucidate the pharmacological activity of LA against UC and will provide valuable information for future studies regarding on the regulatory effects of LA on enteric diseases.

Novel Models for Chronic Intestinal Inflammation in Chickens: Intestinal Inflammation Pattern and Biomarkers

For poultry producers, chronic low-grade intestinal inflammation has a negative impact on productivity by impairing nutrient absorption and allocation of nutrients for growth. Understanding the triggers of chronic intestinal inflammation and developing a non-invasive measurement is crucial to managing gut health in poultry. In this study, we developed two novel models of low-grade chronic intestinal inflammation in broiler chickens: a chemical model using dextran sodium sulfate (DSS) and a dietary model using a high non-starch polysaccharide diet (NSP). Further, we evaluated the potential of several proteins as biomarkers of gut inflammation. For these experiments, the chemical induction of inflammation consisted of two 5-day cycles of oral gavage of either 0.25mg DSS/ml or 0.35mg DSS/ml; whereas the NSP diet (30% rice bran) was fed throughout the experiment. At four times (14, 22, 28 and 36-d post-hatch), necropsies were performed to collect intestinal samples for histology, and feces and serum for biomarkers quantification. Neither DSS nor NSP treatments affected feed intake or livability. NSP-fed birds exhibited intestinal inflammation through 14-d, which stabilized by 36-d. On the other hand, the cyclic DSS-treatment produced inflammation throughout the entire experimental period. Histological examination of the intestine revealed that the inflammation induced by both models exhibited similar spatial and temporal patterns with the duodenum and jejunum affected early (at 14-d) whereas the ileum was compromised by 28-d. Calprotectin (CALP) was the only serum protein found to be increased due to inflammation. However, fecal CALP and Lipocalin-2 (LCN-2) concentrations were significantly greater in the induced inflammation groups at 28-d. This experiment demonstrated for the first time, two in vivo models of chronic gut inflammation in chickens, a DSS and a nutritional NSP protocols. Based on these models we observed that intestinal inflammation begins in the upper segments of small intestine and moved to the lower region over time. In the searching for a fecal biomarker for intestinal inflammation, LCN-2 showed promising results. More importantly, calprotectin has a great potential as a novel biomarker for poultry measured both in serum and feces.

Protective Effects of Idebenone against Sepsis Induced Acute Lung Damage

BACKGROUND/AIMS

Sepsis is an uncontrolled systemic infection, withcomplex pathophysiology that may result in acute lung organ damage and cause multiple organ failure. Although much research has been conducted to illuminate sepsis's complex pathophysiology, sepsis treatment protocols are limited, and sepsis remains an important cause of mortality andmorbidity in intensive care units.Various studies have shown that idebenone (IDE) possesses strong antioxidant properties, which inhibit lipid peroxidation and protect cells from oxidative damage. The present study aimed to evaluate the protective effects of IDE against lung injury in a cecal ligation and puncture (CLP)-induced sepsis rat model.

METHODS

Male albino Wistar rats were used. The animals were divided into a healthy control (no treatment), CLP, IDE control (200 mg/kg), and CLP + IDE subgroups (50 mg/kg, 100 mg/kg, and 200 mg/kg), with nine rats in each group.IDE was administered 1 h after CLP induction.To evaluate the protective effects of IDE, lung tissues were collected 16 h after sepsis for biochemical, immunohistochemical staining, and histopathological examination.

RESULTS

IDE significantly ameliorated sepsis-induced disturbances in oxidative stress-related factors, with its effects increasing in accordance with the dose.IDE also abolished histopathological changes in lung tissues associated with CLP.Furthermore, interleukin 1 beta (IL-1β)and tumor necrosis factor-alpha (TNF-α) immunopositivity markedly decreased in the septic rats following IDE treatment.

CONCLUSIONS

IDE largely mitigated the inflammatory response in sepsis-induced lung injury by decreasing free radicals and preventing lipid peroxidation. The results suggest that IDE may represent a potential novel therapeutic drug for sepsis treatment.

Self-Nanoemulsifying Drug Delivery System of Genkwanin: A Novel Approach for Anti-Colitis-Associated Colorectal Cancer

PURPOSE

The aim of the present study was to develop an optimized Genkwanin (GKA)-loaded self-nanoemulsifying drug delivery system (SNEDDS) formulation to enhance the solubility, intestinal permeability, oral bioavailability and anti-colitis-associated colorectal cancer (CAC) activity of GKA.

METHODS

We designed a SNEDDS comprised oil phase, surfactants and co-surfactants for oral administration of GKA, the best of which were selected by investigating the saturation solubility, constructing pseudo-ternary phase diagrams, followed by optimizing thermodynamic stability, emulsification efficacy, self-nanoemulsification time, droplet size, transmission electron microscopy (TEM), drug release and intestinal permeability. In addition, the physicochemical properties and pharmacokinetics of GKA-SNEDDS were characterized, and its anti-colitis-associated colorectal cancer (CAC) activity and potential mechanisms were evaluated in AOM/DSS-induced C57BL/6J mice model.

RESULTS

The optimized nanoemulsion formula (OF) consists of Maisine CC, Labrasol ALF and Transcutol HP in a weight ratio of 20:60:20 (w/w/w), in which ratio the OF shows multiple improvements, specifically small mean droplet size, excellent stability, fast release properties as well as enhanced solubility and permeability. Pharmacokinetic studies demonstrated that compared with GKA suspension, the relative bioavailability of GKA-SNEDDS was increased by 353.28%. Moreover, GKA-SNEDDS not only significantly prevents weight loss and improves disease activity index (DAI) but also reduces the histological scores of inflammatory cytokine levels as well as inhibiting the formation of colon tumors via inducing tumor cell apoptosis in the AOM/DSS-induced CAC mice model.

CONCLUSION

Our results show that the developed GKA-SNEDDS exhibited enhanced oral bioavailability and excellent anti-CAC efficacy. In summary, GKA-SNEDDS, using lipid nanoparticles as the drug delivery carrier, can be applied as a potential drug delivery system for improving the clinical application of GKA.

Idebenone: When an antioxidant is not an antioxidant

Idebenone is a well described drug that was initially developed against dementia. The current literature widely portrays this molecule as a potent antioxidant and CoQ₁₀ analogue. While numerous papers seem to support this view, a closer look indicates that the pharmacokinetics of idebenone do not support these claims. A major discrepancy between achievable tissue levels, especially in target tissues such as the brain, and doses required to show the proposed effects, significantly questions our current understanding. This review explains how this has happened and highlights the discrepancies in the current literature. More importantly, based on some recent discoveries, a new framework is presented that can explain the mode of action of this molecule and can align formerly contradictory results. Finally, this new appreciation of the molecular activities of idebenone provides a rational approach to test idebenone in novel indications that might have not been considered previously for this drug.

Idebenone Protects against Spontaneous Chronic Murine Colitis by Alleviating Endoplasmic Reticulum Stress and Inflammatory Response

Endoplasmic reticulum (ER) stress in intestinal secretory goblet cells has been linked to the development of ulcerative colitis (UC). Emerging evidence suggests that the short chain quinone drug idebenone displays anti-inflammatory activity in addition to its potent antioxidant and mitochondrial electron donor properties. This study evaluated the impact of idebenone in Winnie mice, that are characterized by spontaneous chronic intestinal inflammation and ER stress caused by a missense mutation in the mucin MUC2 gene. Idebenone (200 mg/kg) was orally administered daily to 5-6 weeks old Winnie mice over a period of 21 days. Idebenone treatment substantially improved body weight gain, disease activity index (DAI), colon length and histopathology score. Immunohistochemistry revealed increased expression of MUC2 protein in goblet cells, consistent with increased MUC2 mRNA levels. Furthermore, idebenone significantly reduced the expression of the ER stress markers C/EBP homologous protein (CHOP), activating transcription factor 6 (ATF6) and X-box binding protein-1 (XBP-1) at both mRNA and protein levels. Idebenone also effectively reduced pro-inflammatory cytokine levels in colonic explants. Taken together, these results indicate that idebenone could represent a potential therapeutic approach against human UC by its strong anti-inflammatory activity and its ability to reduce markers of ER stress.