Antioxidant potential of CORM-A1 and resveratrol during TNF-α/cycloheximide-induced oxidative stress and apoptosis in murine intestinal epithelial MODE-K cells

An orally active carbon monoxide-releasing molecule enhances beneficial gut microbial species to combat obesity in mice

Carbon monoxide (CO), a gaseous signaling molecule, has shown promise in preventing body weight gain and metabolic dysfunction induced by high fat diet (HFD), but the mechanisms underlying these effects are largely unknown. An essential component in response to HFD is the gut microbiome, which is significantly altered during obesity and represents a target for developing new therapeutic interventions to fight metabolic diseases. Here, we show that CO delivered to the gut by oral administration with a CO-releasing molecule (CORM-401) accumulates in faeces and enriches a variety of microbial species that were perturbed by a HFD regimen. Notably, Akkermansia muciniphila, which exerts salutary metabolic effects in mice and humans, was strongly depleted by HFD but was the most abundant gut species detected after CORM-401 treatment. Analysis of bacterial transcripts revealed a restoration of microbial functional activity, with partial or full recovery of the Krebs cycle, β-oxidation, respiratory chain and glycolysis. Mice treated with CORM-401 exhibited normalization of several plasma and fecal metabolites that were disrupted by HFD and are dependent on Akkermansia muciniphila's metabolic activity, including indoles and tryptophan derivatives. Finally, CORM-401 treatment led to an improvement in gut morphology as well as reduction of inflammatory markers in colon and cecum and restoration of metabolic profiles in these tissues. Our findings provide therapeutic insights on the efficacy of CO as a potential prebiotic to combat obesity, identifying the gut microbiota as a crucial target for CO-mediated pharmacological activities against metabolic disorders.

Resveratrol alleviates fumonisin-induced intestinal cytotoxicity by modulating apoptosis, tight junction, and inflammation in IPEC-J2 porcine intestinal epithelial cells

Fumonisins are common contaminants in the global food and environment, pose a variety of health risks to humans and animals. However, the method of mitigating fumonisin toxicity is still unclear. Resveratrol is a natural compound with antioxidant and anti-inflammatory properties. In this study, the protective effect of resveratrol against fumonisin-induced intestinal toxicity was investigated by the porcine intestinal epithelial cell line (IPEC-J2). The cells were treated with 0-40 μM fumonisin for 24 or 48 h with or without the 24 h resveratrol (15 μM) pretreatment. The data showed that resveratrol could alleviate the fumonisin B1 (FB1)-induced decrease in cell viability and amplify in membrane permeability. At the same time, it could reduce the accumulation of intracellular reactive oxygen species and increase the expression ranges of Nrf2 and downstream genes (SOD1 and NQO-1), thereby counteracting FB1-induced apoptosis. Furthermore, resveratrol was able to reduce the expression levels of inflammatory factors (TNF-α, IL-1β, and IL-6), increase the expression levels of tight junction proteins (Claudin-1, Occludin, and ZO-1), and the integrity of the IPEC-J2 monolayer. Our data also showed that resveratrol could attenuate the toxicity of the co-occurrence of three fumonisins. It is implied that resveratrol represents a promising protective approach for fumonisin, even other mycotoxins in the future. This provided a new strategy for further blocking and controlling the toxicity of fumonisin, subsequently avoiding adverse effects on the human and animal health.

The Pharmacological Potential of Resveratrol in Reducing Soft Tissue Damage in Osteoarthritis Patients

Osteoarthritis is a degenerative joint disease that causes the cartilage and bone underneath the joint to break down. This causes pain and stiffness. Resveratrol, a polyphenolic compound found in various vegetables, fruits, and red wine, has been studied for its beneficial effects on osteoarthritis. Resveratrol has been shown to target a variety of pathways, including the NF-κB, PI3K/Akt, MAPK/ERK, and AMPK pathways. In particular, resveratrol has been studied for its potential use in treating osteoarthritis, and it has been shown to reduce inflammation, reduce cartilage degradation, and improve joint function. In this review, we discuss the evidence for the pharmacological use of resveratrol in minimizing soft tissue damage associated with osteoarthritis. We summarize the studies on how resveratrol has anti-inflammatory, anti-oxidant, and anti-apoptotic effects, as well as effects on cartilage degradation, osteoblast and synoviocyte proliferation, and cytokine production. We also discuss the possible mechanisms of action of resveratrol in osteoarthritis and its potential as a therapeutic agent. Finally, we discuss the potential risks and adverse effects of long-term resveratrol supplementation. Overall, resveratrol has been found to be a possible treatment for osteoarthritis because of its anti-inflammatory, anti-oxidant, and anti-apoptotic properties, and its ability to control the production of enzymes that break down cartilage, osteoblasts, and synoviocytes. Although numerous clinical studies have demonstrated resveratrol's efficacy as an osteoarthritis management agent, further long-term studies are needed to better understand the safety and potential benefits of using resveratrol for osteoarthritis management.

Chemical Strategies Toward Prodrugs and Fluorescent Probes for Gasotransmitters

Three gaseous molecules are widely accepted as important gasotransmitters in mammalian cells, namely NO, CO and H2S. Due to the pharmacological effects observed in preclinical studies, these three gasotransmitters represent promising drug candidates for clinical translation. Fluorescent probes of the gasotransmitters are also in high demand; however, the mechanisms of actions or the roles played by gasotransmitters under both physiological and pathological conditions remain to be answered. In order to bring these challenges to the attention of both chemists and biologists working in this field, we herein summarize the chemical strategies used for the design of both probes and prodrugs of these three gasotransmitters.

CORM-A1 Alleviates Pro-Atherogenic Manifestations via miR-34a-5p Downregulation and an Improved Mitochondrial Function

Atherogenesis involves multiple cell types undergoing robust metabolic processes resulting in mitochondrial dysfunction, elevated reactive oxygen species (ROS), and consequent oxidative stress. Carbon monoxide (CO) has been recently explored for its anti-atherogenic potency; however, the effects of CO on ROS generation and mitochondrial dysfunction in atherosclerosis remain unexplored. Herein, we describe the anti-atherogenic efficacy of CORM-A1, a CO donor, in in vitro (ox-LDL-treated HUVEC and MDMs) and in vivo (atherogenic diet-fed SD rats) experimental models. In agreement with previous data, we observed elevated miR-34a-5p levels in all our atherogenic model systems. Administration of CO via CORM-A1 accounted for positive alterations in the expression of miR-34a-5p and transcription factors/inhibitors (P53, NF-κB, ZEB1, SNAI1, and STAT3) and DNA methylation pattern, thereby lowering its countenance in atherogenic milieu. Inhibition of miR-34a-5p expression resulted in restoration of SIRT-1 levels and of mitochondrial biogenesis. CORM-A1 supplementation further accounted for improvement in cellular and mitochondrial antioxidant capacity and subsequent reduction in ROS. Further and most importantly, CORM-A1 restored cellular energetics by improving overall cellular respiration in HUVECs, as evidenced by restored OCR and ECAR rates, whereas a shift from non-mitochondrial to mitochondrial respiration was observed in atherogenic MDMs, evidenced by unaltered glycolytic respiration and maximizing OCR. In agreement with these results, CORM-A1 treatment also accounted for elevated ATP production in both in vivo and in vitro experimental models. Cumulatively, our studies demonstrate for the first time the mechanism of CORM-A1-mediated amelioration of pro-atherogenic manifestations through inhibition of miR-34a-5p expression in the atherogenic milieu and consequential rescue of SIRT1-mediated mitochondrial biogenesis and respiration.

TNF-α Inhibitors from Natural Compounds: An Overview, CADD Approaches, and their Exploration for Anti-inflammatory Agents

Inflammation is a natural process that occurs in the organism in response to harmful external agents. Despite being considered beneficial, exaggerated cases can cause severe problems for the body. The main inflammatory manifestations are pain, increased temperature, edema, decreased mobility, and quality of life for affected individuals. Diseases such as arthritis, cancer, allergies, infections, arteriosclerosis, neurodegenerative diseases, and metabolic problems are mainly characterized by an exaggerated inflammatory response. Inflammation is related to two categories of substances: pro- and anti-inflammatory mediators. Among the pro-inflammatory mediators is Tumor Necrosis Factor-α (TNF-α). It is associated with immune diseases, cancer, and psychiatric disorders which increase its excretion. Thus, it becomes a target widely used in discovering new antiinflammatory drugs. In this context, secondary metabolites biosynthesized by plants have been used for thousands of years and continue to be one of the primary sources of new drug scaffolds against inflammatory diseases. To decrease costs related to the drug discovery process, Computer-Aided Drug Design (CADD) techniques are broadly explored to increase the chances of success. In this review, the main natural compounds derived from alkaloids, flavonoids, terpene, and polyphenols as promising TNF-α inhibitors will be discussed. Finally, we applied a molecular modeling protocol involving all compounds described here, suggesting that their interactions with Tyr⁵⁹, Tyr¹¹⁹, Tyr¹⁵¹, Leu⁵⁷, and Gly¹²¹ residues are essential for the activity. Such findings can be useful for research groups worldwide to design new anti-inflammatory TNF-α inhibitors.

Role of Carbon Monoxide in Oxidative Stress-Induced Senescence in Human Bronchial Epithelium

Prolonged or excessive stimulation from inhaled toxins may cause oxidative stress and DNA damage that can lead to stress-induced senescence in epithelial cells, which can contribute to several airway diseases. Mounting evidence has shown carbon monoxide (CO) confers cytoprotective effects. We investigated the effects of CO on oxidative stress-induced senescence in human airway epithelium and elucidated the underlying molecular mechanisms. Here, CO pretreatment reduced H₂O₂-mediated increases in total reactive oxygen species (ROS) production and mitochondrial superoxide in a human bronchial epithelial cell line (BEAS-2B). H₂O₂ treatment triggered a premature senescence-like phenotype with enlarged and flattened cell morphology accompanied by increased SA-β-gal activity, cell cycle arrest in G0/G1, reduced cell viability, and increased transcription of senescence-associated secretory phenotype (SASP) genes. Additionally, exposure to H₂O₂ increased protein levels of cellular senescence markers (p53 and p21), reduced Sirtuin 3 (SIRT3) and manganese superoxide dismutase (MnSOD) levels, and increased p53 K382 acetylation. These H₂O₂-mediated effects were attenuated by pretreatment with a CO-containing solution. SIRT3 silencing induced mitochondrial superoxide production and triggered a senescence-like phenotype, whereas overexpression decreased mitochondrial superoxide production and alleviated the senescence-like phenotype. Air-liquid interface (ALI) culture of primary human bronchial cells, which becomes a fully differentiated pseudostratified mucociliary epithelium, was used as a model. We found that apical and basolateral exposure to H₂O₂ induced a vacuolated structure that impaired the integrity of ALI cultures, increased goblet cell numbers, decreased SCGB1A1+ club cell numbers, increased p21 protein levels, and increased SASP gene transcription, consistent with our observations in BEAS-2B cells. These effects were attenuated in the apical presence of a CO-containing solution. In summary, we revealed that CO has a pivotal role in epithelial senescence by regulating ROS production via the SIRT3/MnSOD/p53/p21 pathway. This may have important implications in the prevention and treatment of age-associated respiratory pathologies.

Effect of Resveratrol Supplementation on Intestinal Oxidative Stress, Immunity and Gut Microbiota in Weaned Piglets Challenged with Deoxynivalenol

(1) Background: Deoxynivalenol (DON) is a general mycotoxin that induces severe intestinal barrier injury in humans and animals. Resveratrol (RES) efficiently exerts anti-inflammatory and antioxidant effects. However, the information regarding RES protecting against DON-induced oxidative stress and intestinal inflammation in piglets is limited. (2) Methods: A total of 64 weaned piglets (Duroc × (Landrace × Yorkshire), 21-d-old, barrow) were randomly allocated to four groups (eight replicate pens per group, each pen containing two piglets) for 28 d. The piglets were fed a control diet (CON) or the CON diet supplemented with 300 mg RES/kg diet (RES group), 3.8 mg DON/kg diet (DON) or both (DON+RES) in a 2 × 2 factorial design. (3) Compared with unsupplemented DON-challenged piglets, RES supplementation in DON-challenged piglets increased ileal villus height and the abundance of ileal SOD1, GCLC and PG1-5 transcripts and Muc2 protein (p < 0.05), while decreasing the mRNA and proteins expression of ileal IL-1β, IL-6 and TNF-α, and malondialdehyde (MDA) levels in plasma and ileum in DON-challenged piglets (p < 0.05). Moreover, the abundances of class Bacilli, order Lactobacillales, family Lactobacillaceae and species Lactobacillus gasseri were increased in DON-challenged piglets fed a RES-supplemented diet compared with those in DON-challenged piglets(p ≤ 0.05). (4) Conclusions: our results indicated that RES supplementation in DON-challenged piglets efficiently attenuated intestinal inflammation and oxidative stress and improved gut microbiota, thereby alleviating DON-induced intestinal barrier injury.

Adaptation to oxidative stress at cellular and tissue level

Several in vitro and in vivo investigations have already proved that cells and tissues, when pre-exposed to low oxidative stress by different stimuli such as chemical, physical agents and environmental factors, display more resistance against subsequent stronger ischaemic injuries, resulting in an adaptive response known as ischaemic preconditioning (IPC). The aim of this review is to report the most recent knowledge about the complex adaptive mechanisms, including signalling transduction pathways, antioxidant systems, apoptotic and inflammation pathways, underlying cell protection against oxidative damage. In addition, an update about in vivo adaptation strategies in response to ischaemic/reperfusion episodes and brain trauma is also given.

Carbon Monoxide Releasing Molecule A1 Reduces Myocardial Damage After Acute Myocardial Infarction in a Porcine Model

ABSTRACT

Infarct size is a major determinant of outcomes after acute myocardial infarction (AMI). Carbon monoxide-releasing molecules (CORMs), which deliver nanomolar concentrations of carbon monoxide to tissues, have been shown to reduce infarct size in rodents. We evaluated efficacy and safety of CORM-A1 to reduce infarct size in a clinically relevant porcine model of AMI. We induced AMI in Yorkshire White pigs by inflating a coronary angioplasty balloon to completely occlude the left anterior descending artery for 60 minutes, followed by deflation of the balloon to mimic reperfusion. Fifteen minutes after balloon occlusion, animals were given an infusion of 4.27 mM CORM-A1 (n = 7) or sodium borate control (n = 6) over 60 minutes. Infarct size, cardiac biomarkers, ejection fraction, and hepatic and renal function were compared amongst the groups. Immunohistochemical analyses were performed to compare inflammation, cell proliferation, and apoptosis between the groups. CORM-A1-treated animals had significant reduction in absolute infarct area (158 ± 16 vs. 510 ± 91 mm2, P < 0.001) and infarct area corrected for area at risk (24.8% ± 2.6% vs. 45.2% ± 4.0%, P < 0.0001). Biochemical markers of myocardial injury also tended to be lower and left ventricular function tended to recover better in the CORM-A1 treated group. There was no evidence of hepatic or renal toxicity with the doses used. The cardioprotective effects of CORM-A1 were associated with a significant reduction in cell proliferation and inflammation. CORM-A1 reduces infarct size and improves left ventricular remodeling and function in a porcine model of reperfused MI by a reduction in inflammation. These potential cardioprotective effects of CORMs warrant further translational investigations.

The protective role of resveratrol against sulfoxaflor-induced toxicity in testis of adult male rats

This work was designed to explore the protective role of resveratrol (RES) against sulfoxaflor (Sulfx)-induced reproductive toxicity in adult male rats. The animals were divided into six groups: Control group, Sulfx treated groups (79.5 and 205 mg/kg/day), RES treated group (20 mg/kg/day), RES + Sulfx treated groups (20 mg/kg Res + 79.5 or 205 mg/kg Sulfx) orally for 28 consecutive days. Testicular samples were collected from all groups at the end of the treatment period. Tissue supernatants were isolated for oxidative stress and cellular energy parameters; tissue samples were prepared for histopathological examination. In addition, caspase-3 activity was calculated to assess spermatogenesis. Finally, DNA laddering assay was performed to detect DNA fragmentation as a hallmark of apoptosis. Our results showed that Sulfx treatment induced a significant increase in testicular levels of MDA, NOx, GSSG and reduced GSH level and cellular energy parameters in a dose-dependent manner compared to the control group. The results were confirmed by histopathological study which showed pathological changes in Sulfx treated groups. A significant increase in caspase 3 and DNA fragmentation was also observed. However, concomitant administration of RES to Sulfx -treated rats showed significant modulation against Sulfx-induced reproductive toxicity and attenuated the biochemical, apoptotic and histopathological changes. In conclusion, our results suggest that exposure to Sulfx at the two selected doses induces testicular toxicity and these effects can be ameliorated by supplementation of RES.

Walnut oil alleviates LPS-induced intestinal epithelial cells injury by inhibiting TLR4/MyD88/NF-κB pathway activation

In this study, we investigated the protective effects of walnut oil (WO) on mouse intestinal epithelial cells using used MODE-K cells as a model and explored the underlying mechanisms. Our data suggested that WO attenuated lipopolysaccharide (LPS)-induced pathological changes and inhibited the rate of LPS-induced apoptosis in MODE-K cells. Furthermore, WO down-regulated LPS-induced gene and protein expression of toll-like receptor 4 (TLR4), myeloid differentiation primary response gene 88 (MyD88), nuclear factor-κB (NF-κB), tumor necrosis factor-α, and interleukin-6. In conclusion, this study shows that WO exerts an anti-inflammatory effect on LPS-induced MODE-K cells injury by inhibiting the TLR4/MyD88/NF-κB pathway activation. Based on our data, a prominent functional food candidate can be provided for inflammatory bowel disease treatment. PRACTICAL APPLICATIONS: Walnut oil (WO) has excellent anti-inflammatory properties and is widely used in traditional dietary supplements. However, whether WO causes anti-lipopolysaccharide (LPS)-induced intestinal injury remains unclear. In this study, we investigated the protective effects of WO on mouse intestinal epithelial cells using MODE-K cells as a model and explored their potential mechanisms. Our data showed that WO ameliorated the pathological morphology, inhibited the apoptosis of LPS-induced MODE-K cell injury, decreased the release of pro-inflammatory cytokines, and down-regulated the related genes and proteins expression of the LPS-TLR4/MyD88/NF-κB inflammatory pathway. The results of this study would enhance the utilization of WO in the prevention of gastrointestinal diseases in animals and humans inflammatory bowel disease as well as in functional foods formulations.

The effects of IGF-1 and erythropoietin on apoptosis and telomerase activity in necrotizing enterocolitis model

BACKGROUND

Apoptosis that occurs after hypoxia/reoxygenation (H/R) has an important role in the pathogenesis of necrotizing enterocolitis (NEC). Telomerase activity, showing the regeneration capacity, may also be important in the recovery process. Therefore, we aimed to investigate the effects of insulin-like growth factor-1 (IGF-1) and erythropoietin (EPO) on apoptosis and telomerase activity in an H/R model.

METHODS

Young mice were divided into four groups each containing ten Balb/c mice. Group 1 (H/R) were exposed to H/R; group 2 and group 3 were pretreated with IGF-1 and EPO, respectively, for 7 days before H/R. Group 4 served as control. Intestinal injury was evaluated by histological scoring and assessment of apoptosis was performed by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) test. Proapoptotic and antiapoptotic gene expressions and telomerase activity were analyzed by real-time PCR.

RESULTS

IGF-1- and EPO-treated animals had decreased histological damage and apoptosis, confirmed by TUNEL test and caspase activity. Telomerase activity was increased in these animals in addition to increased expression of antiapoptotic genes. However, proapoptotic gene expressions were not statistically different.

CONCLUSIONS

The protective effects of IGF-1 and EPO in H/R damage may be through increased expression of antiapoptotic genes and increased telomerase activity, especially for IGF-1.

IMPACT

This is a comprehensive study measuring various variables, namely IGF-1, EPO, apoptosis, apoptotic and antiapoptotic genes, and telomerase activity in the NEC model. The intestinal protective effects of IGF-1 and EPO in H/R damage may occur through increased expression of antiapoptotic genes and increased telomerase activity. To the best of our knowledge, telomerase activity has not been investigated in the NEC model before. Regarding our results, novel strategies may be implemented for the early definitive diagnosis, robust preventive measures, and effective treatment modalities for NEC.

Dietary resveratrol attenuation of intestinal inflammation and oxidative damage is linked to the alteration of gut microbiota and butyrate in piglets challenged with deoxynivalenol

Background

Deoxynivalenol (DON) is a widespread mycotoxin that induces intestinal inflammation and oxidative stress in humans and animals. Resveratrol (RES) effectively exerts anti-inflammatory and antioxidant effects. However, the protective effects of RES on alleviating DON toxicity in piglets and the underlying mechanism remain unclear. Therefore, this study aimed to investigate the effect of RES on growth performance, gut health and the gut microbiota in DON-challenged piglets. A total of 64 weaned piglets [Duroc × (Landrace × Yorkshire), 21-d-old, 6.97 ± 0.10 kg body weight (BW)] were randomly allocated to 4 treatment groups (8 replicate pens per treatment, each pen containing 2 males; n = 16 per treatment) for 28 d. The piglets were fed a control diet (CON) or the CON diet supplemented with 300 mg RES/kg diet (RES group), 3.8 mg DON/kg diet (DON) or both (DON+RES) in a 2 × 2 factorial design.

Results

DON-challenged piglets fed the RES-supplemented diet had significantly decreased D-lactate concentrations and tumor necrosis factor alpha (TNF-α) and interleukin 1 beta (IL-1β) mRNA and protein expression, and increased zonula occludens-1 (ZO-1) mRNA and protein expression compared with those of DON-challenged piglets fed the unsupplemented diet (P < 0.05). Compared with unsupplemented DON-challenged piglets, infected piglets fed a diet with RES showed significantly decreased malondialdehyde (MDA) levelsand increased mRNA expression of antioxidant enzymes and antioxidant genes (i.e., GCLC, GCLM, HO-1, SOD1 and NQO-1) and glutamate-cysteine-ligase modulatory subunit (GCLM) protein expression (P < 0.05). Moreover, RES supplementation significantly abrogated the increase in the proportion of TUNEL-positive cells and the protein expression of caspase3 in DON-challenged piglets (P < 0.05). Finally, RES supplementation significantly increased the abundance of Roseburia and butyrate concentrations, while decreasing the abundances of Bacteroides and unidentified-Enterobacteriaceae in DON-challenged piglets compared with DON-challenged piglets alone (P < 0.05).

Conclusions

RES supplementation improved gut health in DON-challenged piglets by strengthening intestinal barrier function, alleviating intestinal inflammation and oxidative damage, and positively modulating the gut microbiota. The protective effects of RES on gut health may be linked to increased Roseburia and butyrate concentrations, and decreased levels of Bacteroides and unidentified-Enterobacteriaceae.

Heme Oxygenase-1 Signaling and Redox Homeostasis in Physiopathological Conditions

Heme-oxygenase is the enzyme responsible for degradation of endogenous iron protoporphyirin heme; it catalyzes the reaction’s rate-limiting step, resulting in the release of carbon monoxide (CO), ferrous ions, and biliverdin (BV), which is successively reduced in bilirubin (BR) by biliverdin reductase. Several studies have drawn attention to the controversial role of HO-1, the enzyme inducible isoform, pointing out its implications in cancer and other diseases development, but also underlining the importance of its antioxidant activity. The contribution of HO-1 in redox homeostasis leads to a relevant decrease in cells oxidative damage, which can be reconducted to its cytoprotective effects explicated alongside other endogenous mechanisms involving genes like TIGAR (TP53-induced glycolysis and apoptosis regulator), but also to the therapeutic functions of heme main transformation products, especially carbon monoxide (CO), which has been shown to be effective on GSH levels implementation sustaining body’s antioxidant response to oxidative stress. The aim of this review was to collect most of the knowledge on HO-1 from literature, analyzing different perspectives to try and put forward a hypothesis on revealing yet unknown HO-1-involved pathways that could be useful to promote development of new therapeutical strategies, and lay the foundation for further investigation to fully understand this important antioxidant system.

The effects of carbon monoxide releasing molecules on paraquat-induced pulmonary interstitial inflammation and fibrosis

Paraquat, an herbicide used extensively worldwide, can cause severe toxicity in humans and animals, leading to irreversible, lethal lung fibrosis. The potential of CO-releasing molecules (CORMs), substances that release CO (Carbon monoxide) within animal tissues, for treating paraquat-induced ROS generation and inflammation is investigated here. Our results show that the fast CO releaser CORM-3 (4-20 μM) acts as a potential scavenger of free radicals and decreases fibrosis progression by inhibiting paraquat-induced overexpression of connective tissue growth factor and angiotensin II in MRC-5 cells. The slow CO releaser CORM-A1 (5 mg/kg) clearly decreased expression of the lung profibrogenic cytokines COX-2, TNF-α, and α-SMA and serum hydroxyproline, resulting in a lower mortality rate in paraquat-treated mice. Mice treated with higher-dose CORM-A1 (10 mg/kg) had relatively intact lung lobes and fewer fibrotic patches by gross observation, with less collagen deposition, mesangial matrix accumulation, and pulmonary fibrosis resulting from the mitigation of TGF-β overexpression. In conclusion, our data demonstrate for the first time that CORM-A1 alleviated the development of the fibrotic process and improved survival rate in mice exposed to PQ, would be an attractive therapeutic approach to attenuate the progression of pulmonary fibrosis following PQ exposure.

Gly-Pro-Ala peptide and FGSHF3 exert protective effects in DON-induced toxicity and intestinal damage via decreasing oxidative stress

Deoxynivalenol (DON), a common mycotoxin, usually induces oxidative stress and intestinal injury of humans and animals. This study aims to investigate the protective effect of Gly-Pro-Ala (GPA) peptide, isolated from fish skin gelatin hydrolysate fraction 3 (FGSHF3), on alleviating the toxicity and oxidative stress induced by DON in the mice and IPEC-J2 cells. DON treatment decreases average daily gain and feeds intake, which causes enlargement of the liver and spleen. FGSHF3 (200 mg/kg) and GPA (200 mg/kg) treatment significantly increase average daily gain and inhibits enlargement of the liver and spleen. Furthermore, FGSHF3 and GPA treatment significantly alleviates intestinal injury and maintains tight junction in mice and IPEC-J2 cells. FGSHF3 and GPA treatment significantly inhibits ROS and MDA production and enhances antioxidant enzyme activity, such as CAT, SOD-1, GCLM, GCLC, and GSH-PX. Furthermore, FGSHF3 and GPA treatment promote Nrf2 migration from the cytoplasm to the nucleus, resulting in exerting antioxidant effects. And its effects are abolished after Nrf2 is knockdown by siRNA. Overall, our results suggest GPA peptide may be a promising candidate for the alleviation of DON-induced toxicity in humans and animals.

Anti-Inflammatory Action and Mechanisms of Resveratrol

Resveratrol (3,4',5-trihy- droxystilbene), a natural phytoalexin polyphenol, exhibits anti-oxidant, anti-inflammatory, and anti-carcinogenic properties. This phytoalexin is well-absorbed and rapidly and extensively metabolized in the body. Inflammation is an adaptive response, which could be triggered by various danger signals, such as invasion by microorganisms or tissue injury. In this review, the anti-inflammatory activity and the mechanism of resveratrol modulates the inflammatory response are examined. Multiple experimental studies that illustrate regulatory mechanisms and the immunomodulatory function of resveratrol both in vivo and in vitro. The data acquired from those studies are discussed.

Ferulic acid protects cardiomyocytes from TNF-α/cycloheximide-induced apoptosis by regulating autophagy

Acute myocardial infarction (AMI) results in irreversible cardiac cell damage or death because of decreased blood flow to the heart. Apoptosis plays an important role in the process of tissue damage after myocardial infarction (MI), which has pathological and therapeutic implications. Ferulic acid (FA) is a phenolic acid endowed with strong antioxidative and cytoprotective activities. The present study aimed to investigate whether FA protects cardiomyocytes from apoptosis by regulating autophagy, which is a cellular self-digestion process, and one of the first lines of defense against oxidative stress. Apoptosis was induced by TNF-α (10 ng/mL) and cycloheximide (CHX, 5 μg/mL) in rat H9c2 cardiomyocytes. FA-inhibited TNF-α/CHX-induced apoptosis was determined by the quantification of TUNEL-positive cells, and the effect was associated with decreased ROS production and inhibited caspase3 activation. FA treatment enhanced autophagy and increased autophagy-associated protein expression, leading to an inhibition of mTOR signaling. When co-treated with 3-methyladenine (3-MA), an autophagy inhibitor, the anti-apoptotic effect of FA was attenuated. In an in vivo mouse MI model, FA treatment decreased the apoptotic cell number, reduced infarct size, and improved cardiac performance, as determined by histological and echocardiographic assessments. Taken collectively, these results suggest that FA could protect cardiomyocytes from apoptosis by enhancing autophagy.

Heme is required for carbon monoxide activation of mitochondrial BKCa channel

Carbon monoxide (CO) is an endogenously synthesized gaseous mediator and is involved in the regulation of numerous physiological processes. Mitochondria, in which hemoproteins are abundant, are among the targets for CO action. Large-conductance calcium-activated (mitoBK_Ca) channels in the inner mitochondrial membrane share multiple biophysical similarities with the BK_Ca channels of the plasma membrane and could be a potential target for CO. To test this hypothesis, the activity of the mitoBK_Ca channels in human astrocytoma U-87 MG cell mitochondria was assessed with the patch-clamp technique. The effects of CO-releasing molecules (CORMs), such as CORM-2, CORM-401, and CORM-A1, were compared to the application of a CO-saturated solution to the mitoBK_Ca channels in membrane patches. The applied CORMs showed pleiotropic effects including channel inhibition, while the CO-containing solution did not significantly modulate channel activity. Interestingly, CO applied to the mitoBK_Ca channels, which were inhibited by exogenously added heme, stimulated the channel. To summarize, our findings indicate a requirement of heme binding to the mitoBK_Ca channel for channel modulation by CO and suggest that CORMs might have complex unspecific effects on mitoBK_Ca channels.

Resveratrol protects against PM2.5-induced heart defects in zebrafish embryos as an antioxidant rather than as an AHR antagonist

Resveratrol (RSV), a natural polyphenolic compound commonly found in food, has antioxidant and aryl hydrocarbon receptor (AHR) antagonist effects. We have recently demonstrated that AHR mediated reactive oxygen species (ROS) generation contributes to the cardiac developmental toxicity of ambient fine particle matter (PM2.5). Thus, we hypothesized that RSV protects against the cardiac developmental toxicity of PM2.5 by inhibiting ROS generation and AHR activity. To test this concept, we exposed zebrafish embryos to extractable organic matter (EOM) from PM2.5 in the presence or absence of RSV. We found that RSV significantly counteracted EOM-induced cardiac malformations in zebrafish embryos. The EOM-induced ROS production, DNA damage and apoptosis in the heart of zebrafish embryos were also counteracted by RSV supplementation. Furthermore, RSV attenuated EOM-induced changes in the expression of genes involved in cardiac development (nkx2.5, sox9b, axin2), oxidative stress (nrf2a, nrf2b, gstp1, gstp2, sod1, sod2, cat) and apoptosis (p53, bax). However, RSV did not suppress EOM-induced AHR activity. In conclusion, our data indicates that RSV protects against the PM2.5-induced heart malformations by inhibiting oxidative stress rather than through AHR antagonism.

Carbon Monoxide Being Hydrogen Sulfide and Nitric Oxide Molecular Sibling, as Endogenous and Exogenous Modulator of Oxidative Stress and Antioxidative Mechanisms in the Digestive System

Oxidative stress reflects an imbalance between oxidants and antioxidants in favor of the oxidants capable of evoking tissue damage. Like hydrogen sulfide (H₂S) and nitric oxide (NO), carbon monoxide (CO) is an endogenous gaseous mediator recently implicated in the physiology of the gastrointestinal (GI) tract. CO is produced in mammalian tissues as a byproduct of heme degradation catalyzed by the heme oxygenase (HO) enzymes. Among the three enzymatic isoforms, heme oxygenase-1 (HO-1) is induced under conditions of oxidative stress or tissue injury and plays a beneficial role in the mechanism of protection against inflammation, ischemia/reperfusion (I/R), and many other injuries. According to recently published data, increased endogenous CO production by inducible HO-1, its delivery by novel pharmacological CO-releasing agents, or even the direct inhalation of CO has been considered a promising alternative in future experimental and clinical therapies against various GI disorders. However, the exact mechanisms underlying behind these CO-mediated beneficial actions are not fully explained and experimental as well as clinical studies on the mechanism of CO-induced protection are awaited. For instance, in a variety of experimental models related to gastric mucosal damage, HO-1/CO pathway and CO-releasing agents seem to prevent gastric damage mainly by reduction of lipid peroxidation and/or increased level of enzymatic antioxidants, such as superoxide dismutase (SOD) or glutathione peroxidase (GPx). Many studies have also revealed that HO-1/CO can serve as a potential defensive pathway against oxidative stress observed in the liver and pancreas. Moreover, increased CO levels after treatment with CO donors have been reported to protect the gut against formation of acute GI lesions mainly by the regulation of reactive oxygen species (ROS) production and the antioxidative activity. In this review, we focused on the role of H₂S and NO molecular sibling, CO/HO pathway, and therapeutic potential of CO-releasing pharmacological tools in the regulation of oxidative stress-induced damage within the GI tract with a special emphasis on the esophagus, stomach, and intestines and also two solid and important metabolic abdominal organs, the liver and pancreas.

FSGHF3 and peptides, prepared from fish skin gelatin, exert a protective effect on DSS-induced colitis via the Nrf2 pathway

Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), is a chronic inflammatory disease affecting the colon, and its incidence is rising worldwide.

Heme Catabolic Pathway in Inflammation and Immune Disorders

In recent years, the heme catabolic pathway is considered to play an important regulatory role in cell protection, apoptosis, inflammation, and other physiological and pathological processes. An appropriate amount of heme forms the basic elements of various life activities, while when released in large quantities, it can induce toxicity by mediating oxidative stress and inflammation. Heme oxygenase (HO) -1 can catabolize free heme into carbon monoxide (CO), ferrous iron, and biliverdin (BV)/bilirubin (BR). The diverse functions of these metabolites in immune systems are fascinating. Decades work shows that administration of degradation products of heme such as CO and BV/BR exerts protective activities in systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), multiple sclerosis (MS) and other immune disorders. This review elaborates the molecular and biochemical characterization of heme catabolic pathway, discusses the signal transduction and immunomodulatory mechanism in inflammation and summarizes the promising therapeutic strategies based on this pathway in inflammatory and immune disorders.

Protection of Porcine Intestinal-Epithelial Cells from Deoxynivalenol-Induced Damage by Resveratrol via the Nrf2 Signaling Pathway

Deoxynivalenol (DON), a common mycotoxin, usually induces oxidative stress and affects the intestinal health of humans and animals. This study investigated the protective effect of resveratrol (RES), a natural antioxidant, on alleviating the cytotoxicity induced by DON in the porcine intestinal-epithelial cell line (IPEC-J2). Cells were incubated with RES for 24 h and then exposed to DON for another 24 h. Cell viability, proliferation, apoptosis, and oxidative-stress indicators were determined. In comparison with DON-only-treated cells, pretreatment with RES (15 μM) increased the cell viability (79.74 ± 2.02 vs 90.98 ± 2.66%, P < 0.01), improved proliferation (EdU-positive cells, 26.42 ± 1.12 vs 32.05 ± 0.78%, P < 0.01), decreased accumulation of intracellular reactive oxygen species (ROS, 1.68 ± 0.05 vs 1.29 ± 0.06, P < 0.01), stabilized mitochondrial-membrane potential (MMP, 8.98 ± 1.40 vs 2.29 ± 0.76, P < 0.001), and prevented apoptosis induced by DON (13.91 ± 1.20 vs 6.83 ± 0.52%, P < 0.01). RES activated the Nrf2 signaling pathway, and transfection with Nrf2 siRNA abrogated the protection of RES against DON-induced cytotoxicity, accumulation of intracellular ROS, and mitochondria-dependent apoptosis. Collectively, RES protects IPEC-J2 cells against DON-induced damage at least partly via the Nrf2 signaling pathway.

Fish Skin Gelatin Hydrolysate Production by Ginger Powder Induces Glutathione Synthesis To Prevent Hydrogen Peroxide Induced Intestinal Oxidative Stress via the Pept1-p62-Nrf2 Cascade

Gelatin hydrolysate was reported to contain large amounts of biologically active peptides with excellent antioxidant properties. However, its inducement of antioxidant response within cells and the underlying molecular mechanism are far from clear. Here, gelatin from Nile tilapia skin was hydrolyzed by ginger protease to produce antioxidant hydrolysate, and three fish skin gelatin hydrolysate fractions (FSGHFs) were obtained by ultrafiltration. Fractionation of the hydrolysate increased the free radical scavenging capacity of the FSGHFs, particularly FSGHF3, which showed the lowest molecular weight (below 1000 Da). Furthermore, FSGHF3 treatment prior to H2O2 exposure increased cell viability and membrane integrity in IPEC-J2 cells. H2O2-induced ROS production and epithelial barrier damage were suppressed by FSGHF3 pretreatment. FSGHF3 stimulated the nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2), along with increases in the mRNA and protein expression of catalytic and modulatory subunits of γ-glutamylcysteine ligase as well as in the level of glutathione. Silencing of Nrf2 or p62 (an upstream regulator of Nrf2) suppressed FSGHF3-induced Nrf2 activation and its protection against H2O2-induced oxidative stress. Moreover, oligopeptides in FSGHF3 may mediate the cytoprotective effect against oxidative stress, which was confirmed by the result that FSGHF3 failed to inhibit the ROS production in H2O2-exposed cells with the knockdown of Pept1 (an oligopeptide transporter). Therefore, FSGHF3 can induce glutathione synthesis and prevent oxidative stress through the Pept1-p62-Nrf2 cascade and thus may be a functional food for gastrointestinal dysfunction.

AMP-activated protein kinase protects against necroptosis via regulation of Keap1-PGAM5 complex

BACKGROUND

The AMP-activated protein kinase (AMPK) plays critical roles in growth regulation and metabolism reprogramming. AMPK activation protects cells against apoptosis from injury in different cell and animal models. However, its function in necroptosis remains largely unclear.

METHODS AND RESULTS

In the current study, we demonstrated that AMPK was activated upon necroptosis induction and protected mouse embryonic fibroblasts (MEFs) and cardiomyocytes from N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and reactive oxygen species (ROS) induced necroptosis. Activation of AMPK with chemicals A-769662, 2-deoxyglucose (2-DG), and metformin or constitutively active (CA) AMPK markedly decreased necroptosis and cytotoxicity induced by MNNG. In contrast, AMPK inhibitor compound C, dominant negative (DN) AMPK, as well as AMPK shRNAs increased necroptosis and cytotoxicity induced by MNNG. We further showed that AMPK physically associated with a protein complex containing PGAM5 and Keap1 whereby facilitating Keap1-mediated PGAM5 ubiquitination upon necroptosis induction. The AMPK agonist metformin ameliorated myocardial ischemia and reperfusion (IR) injury and reduced necroptosis through down-regulating the expression of PGAM5 in the Langendorff-perfused rat hearts.

CONCLUSION

Activation of AMPK protects against necroptosis via promoting Keap1-mediated PGAM5 degradation. Metformin may act as a valuable agent for the protection of myocardial ischemia and reperfusion injury by activating AMPK and reducing necroptosis.

Carbon Monoxide Ameliorates 6-Hydroxydopamine-Induced Cell Death in C6 Glioma Cells

Carbon monoxide (CO) is well-known as toxic gas and intrinsic signaling molecule such as neurotransmitter and blood vessel relaxant. Recently, it has been reported that low concentration of CO exerts therapeutic actions under various pathological conditions including liver failure, heart failure, gastric cancer, and cardiac arrest. However, little has been known about the effect of CO in neurodegenerative diseases like Parkinson's disease (PD). To test whether CO could exert a beneficial action during oxidative cell death in PD, we examined the effects of CO on 6-hydroxydopamine (6-OHDA)-induced cell death in C6 glioma cells. Treatment of CO-releasing molecule-2 (CORM-2) significantly attenuated 6-OHDA-induced apoptotic cell death in a dose-dependent manner. CORM-2 treatment decreased Bax/Bcl2 ratio and caspase-3 activity, which had been increased by 6-OHDA. CORM-2 increased phosphorylation of NF-E2-related factor 2 (Nrf2) which is a transcription factor regulating antioxidant proteins. Subsequently, CORM-2 also increased the expression of heme oxygenase-1 and superoxide dismutases (CuZnSOD and MnSOD), which were antioxidant enzymes regulated by Nrf2. These results suggest that CO released by CORM-2 treatment may have protective effects against oxidative cell death in PD through the potentiation of cellular adaptive survival responses via activation of Nrf2 and upregulation of heme oxygenase-1, leading to increasing antioxidant defense capacity.

Resveratrol Ameliorates Experimental Alcoholic Liver Disease by Modulating Oxidative Stress

The aim of this study was to investigate the hepatoprotective effects of resveratrol in alcoholic liver disease (ALD). Alcohol was administered to healthy female rats starting from 6% (v/v) and gradually increased to 20% (v/v) by the fifth week. After 16 weeks of intervention, liver enzymes (aspartate aminotransferase [AST] and alanine aminotransferase [ALT]) were analyzed using a chemistry analyzer, while hepatic antioxidant enzymes, oxidative stress markers, and caspase 3 activity were assessed using ELISA kits. Furthermore, hepatic CYP2E1 protein levels and mRNA levels of antioxidant and inflammation-related genes were determined using western blotting and RT-PCR, respectively. The results showed that resveratrol significantly attenuated alcohol-induced elevation of liver enzymes and improved hepatic antioxidant enzymes. Resveratrol also attenuated alcohol-induced CYP2E1 increase, oxidative stress, and apoptosis (caspase 3 activity). Moreover, genes associated with oxidative stress and inflammation were regulated by resveratrol supplementation. Taken together, the results suggested that resveratrol alleviated ALD through regulation of oxidative stress, apoptosis, and inflammation, which was mediated at the transcriptional level. The data suggests that resveratrol is a promising natural therapeutic agent against chronic ALD.

Mechanism of Neonicotinoid Toxicity: Impact on Oxidative Stress and Metabolism

Thousands of tons of neonicotinoids are widely used around the world as broad-spectrum systemic insecticides and veterinary drugs. Researchers originally thought that neonicotinoids exhibited low mammalian toxicity. However, following their widespread use, it became increasingly evident that neonicotinoids could have various toxic effects on vertebrates and invertebrates. The primary focus of this review is to summarize the research progress associated with oxidative stress as a plausible mechanism for neonicotinoid-induced toxicity as well as neonicotinoid metabolism. This review summarizes the research conducted over the past decade into the production of reactive oxygen species, reactive nitrogen species, and oxidative stress as aresult of neonicotinoid treatments, along with their correlation with the toxicity and metabolism of neonicotinoids. The metabolism of neonicotinoids and protection of various compounds against neonicotinoid-induced toxicity based on their antioxidative effects is also discussed. This review sheds new light on the critical roles of oxidative stress in neonicotinoid-induced toxicity to nontarget species.

Differential Effects of CORM-2 and CORM-401 in Murine Intestinal Epithelial MODE-K Cells under Oxidative Stress

Carbon monoxide (CO)-releasing molecules (CO-RMs) are intensively studied to provide cytoprotective and anti-inflammatory effects of CO in inflammatory conditions including intestinal inflammation. The water-soluble CORM-A1 reduced apoptosis and NADPH oxidase (NOX)-derived reactive oxygen species (ROS) induced by tumor necrosis factor (TNF)-α/cycloheximide (CHX) in mouse MODE-K intestinal epithelial cells (IECs), without influencing TNF-α/CHX-induced mitochondrial superoxide anion (O2•–). The aim of the present study in the same model was to comparatively investigate the influence of lipid-soluble CORM-2 and water-soluble CORM-401, shown in vitro to release more CO under oxidative conditions. CORM-2 abolished TNF-α/CHX-induced total cellular ROS whereas CORM-401 partially reduced it, both partially reducing TNF-α/CHX-induced cell death. Only CORM-2 increased mitochondrial O2•– production after 2 h of incubation. CORM-2 reduced TNF-α/CHX-, rotenone- and antimycin-A-induced mitochondrial O2•– production; CORM-401 only reduced the effect of antimycin-A. Co-treatment with CORM-401 during 1 h exposure to H₂O₂ reduced H₂O₂ (7.5 mM)-induced ROS production and cell death, whereas CORM-2 did not. The study illustrates the importance of the chemical characteristics of different CO-RMs. The lipid solubility of CORM-2 might contribute to its interference with TNF-α/CHX-induced mitochondrial ROS signaling, at least in mouse IECs. CORM-401 is more effective than other CO-RMs under H₂O₂-induced oxidative stress conditions.

{Ru(CO)x}-Core complexes with benzimidazole ligands: synthesis, X-ray structure and evaluation of anticancer activity in vivo

fac-[Ru^II(CO)₃Cl₂(MBI)] and -[Ru^II(CO)₃Cl₂(DMBI)] are CO-releasing materials able to link histidines of proteins, and the latter showed antitumor effects in murine colon cancer.

Differential Effects of CORM-2 and CORM-401 in Murine Intestinal Epithelial MODE-K Cells under Oxidative Stress

Carbon monoxide (CO)-releasing molecules (CO-RMs) are intensively studied to provide cytoprotective and anti-inflammatory effects of CO in inflammatory conditions including intestinal inflammation. The water-soluble CORM-A1 reduced apoptosis and NADPH oxidase (NOX)-derived reactive oxygen species (ROS) induced by tumor necrosis factor (TNF)-α/cycloheximide (CHX) in mouse MODE-K intestinal epithelial cells (IECs), without influencing TNF-α/CHX-induced mitochondrial superoxide anion ([Formula: see text]). The aim of the present study in the same model was to comparatively investigate the influence of lipid-soluble CORM-2 and water-soluble CORM-401, shown in vitro to release more CO under oxidative conditions. CORM-2 abolished TNF-α/CHX-induced total cellular ROS whereas CORM-401 partially reduced it, both partially reducing TNF-α/CHX-induced cell death. Only CORM-2 increased mitochondrial [Formula: see text] production after 2 h of incubation. CORM-2 reduced TNF-α/CHX-, rotenone- and antimycin-A-induced mitochondrial [Formula: see text] production; CORM-401 only reduced the effect of antimycin-A. Co-treatment with CORM-401 during 1 h exposure to H₂O₂ reduced H₂O₂ (7.5 mM)-induced ROS production and cell death, whereas CORM-2 did not. The study illustrates the importance of the chemical characteristics of different CO-RMs. The lipid solubility of CORM-2 might contribute to its interference with TNF-α/CHX-induced mitochondrial ROS signaling, at least in mouse IECs. CORM-401 is more effective than other CO-RMs under H₂O₂-induced oxidative stress conditions.

Effects of Ru(CO)3Cl-glycinate on the developmental toxicities induced by X-ray and carbon-ion irradiation in zebrafish embryos

The inhibitory effects of carbon monoxide (CO), generated by Ru(CO)₃Cl-glycinate [CO-releasing molecule (CORM-3)], on developmental toxicity in zebrafish embryos induced by ionizing radiation with different linear energy transfer (LET) were studied. Zebrafish embryos at 5h post-fertilization were irradiated with X-ray (low-LET) and carbon-ion (high-LET) with or without pretreatment of CORM-3 1h before irradiation. CORM-3 pre-treatment showed a significant inhibitory effect on X-ray irradiation-induced developmental toxicity, but had little effect on carbon-ion irradiation-induced developmental toxicity. X-ray irradiation-induced significant increase in ROS levels and cell apoptosis could be modified by CORM-3 pretreatment. However, embryos exposed to carbon-ion irradiation showed significantly increase of cell apoptosis without obvious ROS generation, which could not be attenuated by CORM-3 pretreatment. CORM-3 could inhibit apoptosis induced by ionizing radiation with low-LET as an effective ROS scavenger. The expression of pro-apoptotic genes increased significantly after X-ray irradiation, but increased expression was reduced markedly when CORM-3 was applied before irradiation. Moreover, the protein levels of P53 and γ-H2AX increased markedly after X-ray irradiation, which could be modified by the presence of CORM-3. The protective effect of CORM-3 on X-ray irradiation occurred mainly by suppressing ROS generation and DNA damage, and thus inhibiting the activation of P53 and the mitochondrial apoptotic pathway, leading to the attenuation of cell apoptosis and consequently alleviating X-ray irradiation-induced developmental toxicity at lethal and sub-lethal levels.