Chlorogenic acid, quercetin, coenzyme Q10 and silymarin modulate Keap1-Nrf2/heme oxygenase-1 signaling in thioacetamide-induced acute liver toxicity

Hepatoprotective effects of the xanthine oxidase inhibitor Febuxostat against thioacetamide-induced liver injury in rats: The role of the Nrf2/ HO-1 and TLR4/ NF-κB pathways

Experimental models of liver injury have been established utilizing thioacetamide (TAA), a classic liver toxic chemical that causes organ damage via oxidative stress and inflammatory induction. This study examined the impact of Febuxostat (a xanthine oxidase inhibitor; Febu, 10-15 mg/kg, orally) against TAA (500 mg/kg, i.p.) -induced liver injury in rats. Febu significantly attenuated TAA-induced alterations in liver function parameters, in addition to promoting hepatic antioxidant effects through a significant elevation of Heme-oxygenase-1(HO-1), nuclear factor erythroid 2-related factor2 (Nrf2), reduced glutathione (GSH) and superoxide dismutase (SOD) levels and reduction in hepatic malondialdehyde (MDA) content. Moreover, Febu improved the hepatic anti-inflammatory status by increasing the anti-inflammatory cytokine Interleukin (IL-10) level and reducing the levels of the pro-inflammatory cytokines (Nuclear factor kappa B (NF-κB), IL-1β, high-mobility group box1 (HMGB1), receptor for advanced glycation end products (RAGE), and toll-like receptor4 (TLR4) levels, in addition to suppressing the increased protein and mRNA expression levels of tumor necrosis factor alpha (TNF-α) and IL-6, hepatic expression of TNF-α and activated mitogen-activated protein kinases (p-JNK/p-p38 MAPK). Histopathologically, Febu markedly normalized TAA-induced alteration in liver sections. In conclusion, Febu, in a dose-dependent fashion, refines TAA-induced hepatotoxicity by enhancing antioxidant capabilities and decreasing inflammatory signals.

Apocynin alleviates thioacetamide-induced acute liver injury: Role of NOX1/NOX4/NF-κB/NLRP3 pathways

The liver has a distinctive capacity to regenerate, yet severe acute injury can be life-threatening if not treated appropriately. Inflammation and oxidative stress are central processes implicated in the pathophysiology of acute livery injury. NOX isoforms are important enzymes for ROS generation, NF-κB and NLRP3 activation, its inhibition could be vital in alleviating acute liver injury (ALI). Here in our study, we used apocynin, a natural occurring potent NOX inhibitor, to exploreits potential protective effect against thioacetamide (TAA)-induced ALI through modulating crucial oxidative and inflammatory pathways. Rats were injected once with TAA (500 mg/kg/i.p) and treated with apocynin (10 mg/kg/i.p) twice before TAA challenge. Sera and hepatic tissues were collected for biochemical, mRNA expression, western blot analysis and histopathological assessments. Pretreatment with apocynin improved liver dysfunction evidenced by decreased levels of aminotransferases, ALP, GGT and bilirubin. Apocynin reduced mRNA expression of NOX1 and NOX4 which in turn alleviated oxidative stress, as shown by reduction in MDA and NOx levels, and elevation in GSH levels andcatalase and SOD activities. Moreover, apocynin significantly reduced MPO gene expression. We also demonstrate that apocynin ameliorated inflammation through activating IκBα and suppressing IKKα, IKKβ, NF-κBp65 and p-NF-κBp65, IL-6 andTNF-α. Additionally, apocynin potentiated the gene expression of anti-inflammatory IL-10 and reduced levels of hepatic NLRP3, Caspase-1 and IL-1β. These results suggest that apocynin protects against ALI in association with the inhibition of NOX1 and NOX4 and regulating oxidative and inflammatory pathways.

Multimodal modulation of hepatic ischemia/reperfusion-induced injury by phytochemical agents: A mechanistic evaluation of hepatoprotective potential and safety profiles

BACKGROUND

Hepatic ischemia-reperfusion (I/R) injury is a clinically fundamental phenomenon that occurs through liver resection surgery, trauma, shock, and transplantation.

AIMS OF THE REVIEW

This review article affords an expanded and comprehensive overview of various natural herbal ingredients that have demonstrated hepatoprotective effects against I/R injury through preclinical studies in animal models.

MATERIALS AND METHODS

For the objective of this investigation, an extensive examination was carried out utilizing diverse scientific databases involving PubMed, Google Scholar, Science Direct, Egyptian Knowledge Bank (EKB), and Research Gate. The investigation was conducted based on specific identifiable terms, such as hepatic ischemia/reperfusion injury, liver resection and transplantation, cytokines, inflammation, NF-kB, interleukins, herbs, plants, natural ingredients, phenolic extract, and aqueous extract.

RESULTS

Bioactive ingredients derived from ginseng, curcumin, resveratrol, epigallocatechin gallate, quercetin, lycopene, punicalagin, crocin, celastrol, andrographolide, silymarin, and others and their effects on hepatic IRI were discussed. The specific mechanisms of action, signaling pathways, and clinical relevance for attenuation of liver enzymes, cytokine production, immune cell infiltration, oxidative damage, and cell death signaling in rodent studies are analyzed in depth. Their complex molecular actions involve modulation of pathways like TLR4, NF-κB, Nrf2, Bcl-2 family proteins, and others.

CONCLUSION

The natural ingredients have promising values in the protection and treatment of various chronic aggressive clinical conditions, and that need to be evaluated on humans by clinical studies.

Attenuation of chromium (VI) and arsenic (III)-induced oxidative stress and hepatic apoptosis by phloretin, biochanin-A, and coenzyme Q10 via activation of SIRT1/Nrf2/HO-1/NQO1 signaling

Heavy metal contamination is an alarming concern on a global scale, as drinking tainted water significantly increases human susceptibility to heavy metals. In a realistic scenario, humans are often exposed to a combination of harmful chemicals rather than a single toxicant. Phloretin (PHL), biochanin-A (BCA), and coenzyme Q10 (CoQ10) are bioactive compounds owning plentiful pharmacological properties. Henceforth, the current research explored the putative energizing effects of selected nutraceuticals in combined chromium (Cr) and arsenic (As) intoxicated Swiss albino mice. Potassium dichromate (75 ppm) and sodium meta-arsenite (100 ppm) were given in the drinking water to induce hepatotoxicity, conjugated with PHL and BCA (50 mg/kg each), and CoQ10 (10 mg/kg) intraperitoneally for 2 weeks. After the statistical evaluation, it was observed that the hepato-somatic index, metal load, and antioxidant activity (lipid peroxidation and protein carbonyl content) increased along with the concomitant decrease in the antioxidants (catalase, glutathione-S-transferase, superoxide dismutase, reduced glutathione, and total thiol) in the Cr and As intoxicated mice. Additionally, light microscopy observations, DNA breakages, decreased silent information regulator 1 (SIRT1), nuclear factor (erythroid-derived 2)-like 2 (Nrf2), heme oxygenase (HO-1), and NAD(P)H quinone dehydrogenase 1 (NQO1) gene expressions, together with stimulated apoptotic cell death manifested by the increased expressions of caspase 8 and caspase 3, thus, proved consistency with the aforementioned outcomes. Importantly, the treatment with nutraceuticals not only restored the antioxidant activity but also favorably altered the expressions of SIRT1, Nrf2, HO-1, and NQO1 signaling and apoptosis markers. These findings highlight the crucial role of the PHL, BCA, and CoQ10 combination in reducing Cr and As-induced hepatotoxicity in mice. By averting the triggered apoptosis in conjunction with oxidative stress, this combination increases the SIRT1, Nrf2, HO-1, and NQO1 signaling, thereby reassuringly maintaining the cellular equilibrium.

New perspectives on the therapeutic potential of quercetin in non-communicable diseases: Targeting Nrf2 to counteract oxidative stress and inflammation

Non-communicable diseases (NCDs), including cardiovascular diseases, cancer, metabolic diseases, and skeletal diseases, pose significant challenges to public health worldwide. The complex pathogenesis of these diseases is closely linked to oxidative stress and inflammatory damage. Nuclear factor erythroid 2-related factor 2 (Nrf2), a critical transcription factor, plays an important role in regulating antioxidant and anti-inflammatory responses to protect the cells from oxidative damage and inflammation-mediated injury. Therefore, Nrf2-targeting therapies hold promise for preventing and treating NCDs. Quercetin (Que) is a widely available flavonoid that has significant antioxidant and anti-inflammatory properties. It modulates the Nrf2 signaling pathway to ameliorate oxidative stress and inflammation. Que modulates mitochondrial function, apoptosis, autophagy, and cell damage biomarkers to regulate oxidative stress and inflammation, highlighting its efficacy as a therapeutic agent against NCDs. Here, we discussed, for the first time, the close association between NCD pathogenesis and the Nrf2 signaling pathway, involved in neurodegenerative diseases (NDDs), cardiovascular disease, cancers, organ damage, and bone damage. Furthermore, we reviewed the availability, pharmacokinetics, pharmaceutics, and therapeutic applications of Que in treating NCDs. In addition, we focused on the challenges and prospects for its clinical use. Que represents a promising candidate for the treatment of NCDs due to its Nrf2-targeting properties.

Metabolic Composition of Methanolic Extract of the Balkan Endemic Species Micromeria frivaldszkyana (Degen) Velen and Its Anti-Inflammatory Effect on Male Wistar Rats

Extracts from medicinal plants are widely used in the treatment and prevention of different diseases. Micromeria frivaldszkyana is a Balkan endemic species with reported antioxidant and antimicrobial characteristics; however, its phytochemical composition is not well defined. Here, we examined the metabolome of M. frivaldszkyana by chromatography-mass spectrometry (GC-MS), ultra-performance liquid chromatography-mass spectrometry (UPLC-MS-MS), and inductively coupled plasma mass spectrometry (ICP-MS). Amino acids, organic acids, sugars, and sugar alcohols were the primary metabolites with the highest levels in the plant extract. Detailed analysis of the sugar content identified high levels of sucrose, glucose, mannose, and fructose. Lipids are primary plant metabolites, and the analysis revealed triacylglycerols as the most abundant lipid group. Potassium (K), magnesium (Mg), zinc (Zn), and calcium (Ca) were the elements with the highest content. The results showed linarin, 3-caffeoil-quinic acid, and rosmarinic acid, as well as a number of polyphenols, as the most abundant secondary metabolites. Among the flavonoids and polyphenols with a high presence were eupatorin, kaempferol, and apigenin-compounds widely known for their bioactive properties. Further, the acute toxicity and potential anti-inflammatory activity of the methanolic extract were evaluated in Wistar rats. No toxic effects were registered after a single oral application of the extract in doses of between 200 and 5000 mg/kg bw. A fourteen-day pre-treatment with methanolic extract of M. frivaldszkyana in doses of 250, 400, and 500 mg/kg bw induced anti-inflammatory activity in the 1st, 2nd, and 3rd hours after carrageenan injection in a model of rat paw edema. This effect was also present in the 4th hour only in the group treated with a dose of 500 mg/kg. In conclusion, M. frivaldszkyana extract is particularly rich in linarin, rosmarinic acid, and flavonoids (eupatorin, kaempferol, and apigenin). Its methanolic extract induced no toxicity in male Wistar rats after oral application in doses of up to 5000 mg/kg bw. Additionally, treatment with the methanolic extract for 14 days revealed anti-inflammatory potential in a model of rat paw edema on the 1st, 2nd, and 3rd hours after the carrageenan injection. These results show the anti-inflammatory potential of the plant, which might be considered for further exploration and eventual application as a phytotherapeutic agent.

Mitochondrial dysfunction: A promising therapeutic target for liver diseases

The liver is an important metabolic and detoxification organ and hence demands a large amount of energy, which is mainly produced by the mitochondria. Liver tissues of patients with alcohol-related or non-alcohol-related liver diseases contain ultrastructural mitochondrial lesions, mitochondrial DNA damage, disturbed mitochondrial dynamics, and compromised ATP production. Overproduction of mitochondrial reactive oxygen species induces oxidative damage to mitochondrial proteins and mitochondrial DNA, decreases mitochondrial membrane potential, triggers hepatocyte inflammation, and promotes programmed cell death, all of which impair liver function. Mitochondrial DNA may be a potential novel non-invasive biomarker of the risk of progression to liver cirrhosis and hepatocellular carcinoma in patients infected with the hepatitis B virus. We herein present a review of the mechanisms of mitochondrial dysfunction in the development of acute liver injury and chronic liver diseases, such as hepatocellular carcinoma, viral hepatitis, drug-induced liver injury, alcoholic liver disease, and non-alcoholic fatty liver disease. This review also discusses mitochondrion-centric therapies for treating liver diseases.

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

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

Silymarin and Inflammation: Food for Thoughts

Inflammation is a vital defense mechanism, creating hostile conditions for pathogens, preventing the spread of tissue infection and repairing damaged tissues in humans and animals. However, when inflammation resolution is delayed or compromised as a result of its misregulation, the process proceeds from the acute phase to chronic inflammation, leading to the development of various chronic illnesses. It is proven that redox balance disturbances and oxidative stress are among major factors inducing NF-κB and leading to over-inflammation. Therefore, the anti-inflammatory properties of various natural antioxidants have been widely tested in various in vitro and in vivo systems. Accumulating evidence indicates that silymarin (SM) and its main constituent silibinin/silybin (SB) have great potential as an anti-inflammation agent. The main anti-inflammatory mechanism of SM/SB action is attributed to the inhibition of TLR4/NF-κB-mediated signaling pathways and the downregulated expression of pro-inflammatory mediators, including TNF-α, IL-1β, IL-6, IL-12, IL-23, CCL4, CXCL10, etc. Of note, in the same model systems, SM/SB was able to upregulate anti-inflammatory cytokines (IL-4, IL-10, IL-13, TGF-β, etc.) and lipid mediators involved in the resolution of inflammation. The inflammatory properties of SM/SB were clearly demonstrated in model systems based on immune (macrophages and monocytes) and non-immune (epithelial, skin, bone, connective tissue and cancer) cells. At the same time, the anti-inflammatory action of SM/SB was confirmed in a number of in vivo models, including toxicity models, nonalcoholic fatty liver disease, ischemia/reperfusion models, stress-induced injuries, ageing and exercising models, wound healing and many other relevant model systems. It seems likely that the anti-inflammatory activities of SM/SB are key elements on the health-promoting properties of these phytochemicals.

Dimethyl Bisphenolate Ameliorates Carbon Tetrachloride-Induced Liver Injury by Regulating Oxidative Stress-Related Genes

Liver disease accounts for millions of deaths per year all over the world due to complications from cirrhosis and liver injury. In this study, a novel compound, dimethyl bisphenolate (DMB), was synthesized to investigate its role in ameliorating carbon tetrachloride (CCl4)-induced liver injury through the regulation of oxidative stress-related genes. The structure of DMB was confirmed based on its hydrogen spectrum and mass spectrometry. DMB significantly reduced the high levels of ALT, AST, DBIL, TBIL, ALP, and LDH in a dose-dependent manner in the sera of CCl4-treated rats. The protective effects of DMB on biochemical indicators were similar to those of silymarin. The ROS fluorescence intensity increased in CCl4-treated cells but significantly weakened in DMB-treated cells compared with the controls. DMB significantly increased the content of oxidative stress-related GSH, Nrf2, and GCLC dose-dependently but reduced MDA levels in CCl4-treated cells or the liver tissues of CCl4-treated rats. Moreover, DMB treatment decreased the expression levels of P53 and Bax but increased those of Bcl2. In summary, DMB demonstrated protective effects on CCl4-induced liver injury by regulating oxidative stress-related genes.

Interactive effects of cadmium and titanium dioxide nanoparticles on hepatic tissue in rats: Ameliorative role of coenzyme 10 via modulation of the NF-κB and TNFα pathway

This study investigated the effect of oral dosing of titanium dioxide nanoparticles (TNPs) and cadmium (Cd2+) on rat liver and the potential protective role of coenzyme Q10 (CQ10) against TNPs and Cd2+-induced hepatic injury. Seventy male Sprague Dawley rats were divided into seven groups and orally given distilled water, corn oil, CQ10 (10 mg/kg b.wt), TNPs (50 mg/kg b.wt), Cd2+ (5 mg/kg b.wt), TNPs + Cd2+, or TNPs + Cd2++CQ10 by gastric gavage for 60 successive days. The results showed that individual or mutual exposure to TNPs and Cd2+ significantly increased the serum levels of various hepatic enzymes and lipids, depleted the hepatic content of antioxidant enzymes, and increased malondialdehyde. Moreover, the hepatic titanium and Cd2+ content were increased considerably in TNPs and/or Cd2+-exposed rats. Furthermore, marked histopathological perturbations with increased immunoexpression of tumor necrosis factor-alpha and nuclear factor kappa B were evident in TNPs and/or Cd2+-exposed rats. However, CQ10 significantly counteracted the damaging effect of combined exposure of TNPs and Cd2+ on the liver. The study concluded that TNPs and Cd2+ exposure harm hepatic function and its architecture, particularly at their mutual exposure, but CQ10 could be a candidate protective agent against TNPs and Cd2+ hepatotoxic impacts.

Chlorogenic acids: A pharmacological systematic review on their hepatoprotective effects

BACKGROUND

Liver diseases have a negative impact on global health and are a leading cause of death worldwide. Chlorogenic acids (CGAs), a family of esters formed between certain trans-cinnamic acids and quinic acid, are natural polyphenols abundant in coffee, tea, and a variety of traditional Chinese medicines (TCMs). They are reported to have good hepatoprotective effects against various liver diseases.

PURPOSE

This review aims to analyze the available literature on the hepatoprotective effect of CGAs, with particular emphasis on their mechanisms.

METHODS

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. PubMed and Web of Science databases were adopted to retrieve all relevant literature on CGAs for liver disease from 2013 to March 2023.

RESULTS

Research has indicated that CGAs play a crucial role in improving different types of liver diseases, including drug-induced liver injury (DILI), alcoholic liver disease (ALD), metabolic (dysfunction)-associated fatty liver disease (MAFLD), cholestatic liver disease (CLD), liver fibrosis, and liver cancer. CGAs display remarkable antioxidant and anti-inflammatory effects by activating erythroid 2-related factor 2 (Nrf2) and inhibiting toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) signaling pathways. Some important molecules such as AMP-activated protein kinase (AMPK) and extracellular signal-regulated kinases 1 and 2 (ERK1/2), and other key physiological processes like intestinal barrier and gut microbiota have also been discovered to participate in CGAs-provided amelioration on various liver diseases.

CONCLUSION

In this review, different studies indicate that CGAs have an excellent protective effect against various liver diseases associated with various signaling pathways.

Advances in Understanding the Role of NRF2 in Liver Pathophysiology and Its Relationship with Hepatic-Specific Cyclooxygenase-2 Expression

Oxidative stress and inflammation play an important role in the pathophysiological changes of liver diseases. Nuclear factor erythroid 2-related factor 2 (NRF2) is a transcription factor that positively regulates the basal and inducible expression of a large battery of cytoprotective genes, thus playing a key role in protecting against oxidative damage. Cyclooxygenase-2 (COX-2) is a key enzyme in prostaglandin biosynthesis. Its expression has always been associated with the induction of inflammation, but we have shown that, in addition to possessing other benefits, the constitutive expression of COX-2 in hepatocytes is beneficial in reducing inflammation and oxidative stress in multiple liver diseases. In this review, we summarized the role of NRF2 as a main agent in the resolution of oxidative stress, the crucial role of NRF2 signaling pathways during the development of chronic liver diseases, and, finally we related its action to that of COX-2, where it appears to operate as its partner in providing a hepatoprotective effect.

The Potential Effects of Quercetin-Loaded Nanoliposomes on Amoxicillin/Clavulanate-Induced Hepatic Damage: Targeting the SIRT1/Nrf2/NF-κB Signaling Pathway and Microbiota Modulation

Amoxicillin/clavulanate (Co-Amox), a commonly used antibiotic for the treatment of bacterial infections, has been associated with drug-induced liver damage. Quercetin (QR), a naturally occurring flavonoid with pleiotropic biological activities, has poor water solubility and low bioavailability. The objective of this work was to produce a more bioavailable formulation of QR (liposomes) and to determine the effect of its intraperitoneal pretreatment on the amelioration of Co-Amox-induced liver damage in male rats. Four groups of rats were defined: control, QR liposomes (QR-lipo), Co-Amox, and Co-Amox and QR-lipo. Liver injury severity in rats was evaluated for all groups through measurement of serum liver enzymes, liver antioxidant status, proinflammatory mediators, and microbiota modulation. The results revealed that QR-lipo reduced the severity of Co-Amox-induced hepatic damage in rats, as indicated by a reduction in serum liver enzymes and total liver antioxidant capacity. In addition, QR-lipo upregulated antioxidant transcription factors SIRT1 and Nrf2 and downregulated liver proinflammatory signatures, including IL-6, IL-1β, TNF-α, NF-κB, and iNOS, with upregulation in the anti-inflammatory one, IL10. QR-lipo also prevented Co-Amox-induced gut dysbiosis by favoring the colonization of Lactobacillus, Bifidobacterium, and Bacteroides over Clostridium and Enterobacteriaceae. These results suggested that QR-lipo ameliorates Co-Amox-induced liver damage by targeting SIRT1/Nrf2/NF-κB and modulating the microbiota.

SIRT1/Nrf2/NF-κB Signaling Mediates Anti-Inflammatory and Anti-Apoptotic Activities of Oleanolic Acid in a Mouse Model of Acute Hepatorenal Damage

Background and objectives: Oleanolic acid (OA) is a penta-cyclic triterpene with diverse bioactivities such as anticarcinogenic, antiviral, antimicrobial, hepatoprotective, anti-atherosclerotic, hypolipidemic, and gastroprotective. However, its effects on hepatorenal damage remain unclear. The protective activity of OA, separated from Viscum schimperi (Loranthaceae), against TAA (thioacetamide)-produced acute hepatic and renal damage was explored. Materials and Methods: Mice were treated with OA for 7 days before TAA (200 mg/kg, i.p.). Serum indices of hepatorenal injury, pathological lesions, molecular biological indexes, and inflammatory/apoptotic genes were estimated. Results: The tissues of both organs were greatly affected by the TAA injection. That was evident through increased serum markers of hepato-renal injury as well as remarkable histopathological lesions. TAA-induced injury was associated with oxidative and inflammatory responses in both organs as there was an elevation of oxidative stress parameters (4-HNE (4-hydroxy-nonenal), MDA (malondialdehyde), NOx (nitric oxide)), decline of antioxidants (reduced glutathione (GSH), superoxide dismutase (SOD), and total antioxidant capacity (TAC)), and an increase in the gene expression/level of inflammatory mediators (interleukins (1β&6)). The inflammatory response was linked to a significant activation of NF-κB (nuclear-factor kappa-B)/TNF-α (tumor-necrosis factor-alpha) signaling. The inflammatory response in both organs was accompanied by apoptotic changes, including a rise in the gene expression and level of apoptotic parameters (caspase-3 and Bax) along with a decline in Bcl-2 (anti-apoptotic parameter) gene expression and level. These pathogenic events were found to be closely related to the suppression of the antioxidant signaling pathway, Nrf2 (nuclear-factor erythroid 2-related factor-2)/SIRT1 (sirtuin-1)/HO-1 (heme-oxygenase 1). On the other hand, OA significantly ameliorated TAA-induced injury in both organs. On the other hand, OA counterpoised the inflammatory response as it ameliorated NF-κB/TNF-α signaling and cytokine release. OA enhanced Nrf2/SIRT1/HO-1 signaling and counteracted apoptotic damage. Conclusions: OA showed anti-inflammation and antiapoptotic capacities that effectively suppressed TAA-induced acute hepatorenal damage.

Protective effect of quercetin on avermectin induced splenic toxicity in carp: Resistance to inflammatory response and oxidative damage

Avermectin pollution is an important problem that cannot be ignored in aquatic system in recent years. It has brought great trouble to freshwater aquaculture, especially fishery aquaculture. Plant-derived quercetin has anti-inflammatory and antioxidant properties and is widely used as a dietary additive, but its protective effect on immune damage induced by avermectin in freshwater carp remains unclear. This study evaluated the role of dietary additive quercetin supplementation in chronic avermectin exposure of carp spleen. Sixty carp were divided into 4 groups (n = 15/ group), including control group, avermectin treatment group, quercetin treatment group, quercetin and avermectin co-treatment group. Carp were exposed to a 1/10 96 h LC₅₀ dose of avermectin for 30 d and fed a carp diet containing 400 mg/kg quercetin twice a day (3% body weigh/ carp). The results showed that chronic avermectin exposure caused the loose parenchymal structure of carp spleen tissue and the increase of inflammatory cells, accompanied by increased transcription levels of pro-inflammatory il-1β, il-6, tnf-α and decreased levels of anti-inflammatory factors il-10 and tgf-β1, ROS accumulation in spleen tissue. MDA content increased and T-AOC, CAT and GSH levels decreased. Quercetin down-regulates the NF-κB pathway by inhibiting the expression of iNOS and activating p38 MAPK, blocking the transcription of inflammatory factors, and alleviating the inflammation of carp spleen caused by chronic avermectin exposure. In addition, quercetin inhibits the over-activation of Nrf2/Keap-1 signaling axis, blocks ROS accumulation, and restores the spleen REDOX homeostasis. In conclusion, quercetin, as a dietary additive for carp feed, can effectively improve the immune damage caused by avermectin pollution in aquatic environment, resist spleen inflammation and oxidative stress, and provide a theoretical basis for clinical development of freshwater carp feed.

Thiamethoxam Evoked Neural Oxido-inflammatory Stress in Male Rats Through Modulation of Nrf2/NF-kB/iNOS Signaling and Inflammatory Cytokines: Neuroprotective Effect of Silymarin

Thiamethoxam (TMX), a neonicotinoid insecticide, is a widely used insecticide with neurotoxic potential. Silymarin (SM), a milk thistle-derived flavonoid, is known with its promising biological activities. This study explored the neuroprotective effects of SM against TMX-triggered cortical injury in male rats. Animals were divided into four groups and treated daily either with SM (150mg/kg), TMX (78.15mg/kg), or both at the aforementioned doses for 28 days. Our results revealed marked declines in cortical SOD and CAT activities with elevations in MDA, IL-1b and TNF-α levels in TMX-treated rats. Further, TMX induced down-regulation in the gene expressions of Sod, Cat, Gpx, and Nrf-2, with up-regulation in the gene expressions of IL-1b, IL-6, iNOS, TNF-α and NF-kB. Interestingly, pre-treatment with SM provided a notable neuroprotective action against TMX-mediated cortical damage that indicates its promising antioxidant and anti-inflammatory activities. This effect may be mediated by Nrf2/NF-kB/iNOS signalling and suppression of excess free radicals and production of inflammatory cytokines. In brief, SM could be a promising therapeutic agent against TMX-mediated neural complication via its antioxidant and anti-inflammatory properties. PRACTICAL APPLICATIONS: The using of neonicotinoids as thiamethoxam is recently increased and is associated with brain damage. TMX induced excessive oxidative and inflammatory damage. Therefore, new therapeutic approaches are needed to counteract its adverse effects on the nervous system. SM, a flavonoid, is extracted from the seeds and fruits of milk thistle. Due to its potent antioxidative activity, SM have been applied to mitigate the oxidative stress as well as inflammatory disorders. Herein, we examined the potential therapeutic role of SM against TMX-induced brain oxidative stress and inflammation in rats through evaluating oxidative markers, inflammatory response, and histopathological changes in the brain cortical tissue.

Thymol protects against bleomycin-induced pulmonary fibrosis via abrogation of oxidative stress, inflammation, and modulation of miR-29a/TGF-β and PI3K/Akt signaling in mice

Idiopathic pulmonary fibrosis is a terminal lung ailment that shares several pathological and genetic mechanisms with severe COVID-19. Thymol (THY) is a dietary compound found in thyme species that showed therapeutic effects against various diseases. However, the effect of THY against bleomycin (BLM)-induced lung fibrosis was not previously investigated. The current study investigated the ability of THY to modulate oxidative stress, inflammation, miR-29a/TGF-β expression, and PI3K/phospho-Akt signaling in lung fibrosis. Mice were divided into Normal, THY (100 mg/kg, p.o.), BLM (15 mg/kg, i.p.), BLM + THY (50 mg/kg, p.o.), and BLM + THY (100 mg/kg, p.o.) groups and treated for four weeks. The obtained results showed that BLM + THY (50 mg/kg) and BLM + THY (100 mg/kg) reduced fibrotic markers; α-SMA and fibronectin, inflammatory mediators; TNF-α, IL-1β, IL-6, and NF-kB and oxidative stress biomarkers; MDA, GSH, and SOD, relative to BLM group. Lung histopathological examination by H&E and Masson's trichrome stains confirmed the obtained results. Remarkably, expression levels of TGF-β, PI3K, and phospho-Akt were decreased while miR-29a expression was elevated. In conclusion, THY effectively prevented BLM-induced pulmonary fibrosis by exerting significant anti-oxidant and anti-inflammatory effects. Our novel findings that THY upregulated lung miR-29a expression while decreased TGF-β and PI3K/Akt signaling are worthy of further investigation as a possible molecular mechanism for THY's anti-fibrotic actions.

Silymarin Protects against Acute Liver Injury Induced by Acetaminophen by Downregulating the Expression and Activity of the CYP2E1 Enzyme

Previous studies have shown that silymarin protects against various types of drug-induced liver injury, but whether the protective mechanism of silymarin against acetaminophen-induced liver injury is related to the CYP2E1 enzyme remains unclear. In this study, we investigated the effect of silymarin on the activity and expression of CYP2E1 in vitro and in vivo. The results of in vitro studies showed that silymarin not only inhibited the activity of CYP2E1 in human and rat liver microsomes but also reduced the expression of CYP2E1 in HepG2 cells. In vivo studies showed that silymarin pretreatment significantly reduced the conversion of chlorzoxazone to its metabolite 6-OH-CLX and significantly increased the t1/2, area under the curve (AUC) and mean residence time (MRT) of chlorzoxazone. In addition, silymarin pretreatment significantly inhibited the upregulation of Cyp2e1 expression, reduced the production of 3-cysteinylacetaminophen trifluoroacetic acid salt (APAP-CYS), and restored the liver glutathione level. The results of our study show that silymarin plays an important protective role in the early stage of acetaminophen-induced acute liver injury by reducing the activity and expression of CYP2E1, reducing the generation of toxic metabolites, and alleviating liver injury.

Phytoprofiling of Sorbus L. Inflorescences: A Valuable and Promising Resource for Phenolics

The leaves and fruits of various Sorbus L. genotypes have long ethnopharmacological and food-usage histories, but inflorescences are still underutilized and neglected materials with scarce phytochemical scientific evidence. The aim of this study was to determine the phenolic profiles of inflorescence extracts of 26 Sorbus species, genotypes, and cultivars. HPLC and UPLS with MS detection were applied, and coupled data revealed unique phytochemical phenolic profiles. Neochlorogenic and chlorogenic acids were the key compounds, reaching up to 5.8 mg/g of dw. Rutin, isoquercitrin, quercetin 3-O-malonylglucoside, isorhamnetin 3-O-rutinoside, sexangularetin derivative, and kaempferol acetyl hexoside were detected in all Sorbus inflorescence samples. Overall, high quantitative heterogeneity across the various Sorbus genotypes was found by profiling. Phenolic fingerprint profiles and sexangularetin derivatives could serve as markers in authenticity studies and quality control schemes. The species S. amurensis, S. arranensis, S. commixta, and S. discolor and the cultivars 'Chamsis Louing', 'Coral Beauty', and 'Edulis' could be used as target genotypes for production of smart and innovative inflorescence matrix-based ingredients.

Molecular mechanisms underlying the renal protective effects of coenzyme Q10 in acute kidney injury

Coenzyme Q10 (CoQ10), an endogenous antioxidant, has been reported frequently to exert an outstanding protective effect on multiple organ injury, including acute kidney injury (AKI). In this study, we aim to summarize all the current evidence of the protective action of CoQ10 against AKI as there are presently no relevant reviews in the literature. After a systematic search, 20 eligible studies, either clinical trials or experimental studies, were included and further reviewed. CoQ10 treatment exhibited a potent renal protective effect on various types of AKI, such as AKI induced by drugs (e.g., ochratoxin A, cisplatin, gentamicin, L-NAME, and nonsteroidal anti-inflammatory drug), extracorporeal shock wave lithotripsy (ESWL), sepsis, contrast media, and ischemia–reperfusion injury. The renal protective role of CoQ10 against AKI might be mediated by the antiperoxidative, anti-apoptotic, and anti-inflammatory potential of CoQ10. The molecular mechanisms for the protective effects of CoQ10 might be attributed to the regulation of multiple essential genes (e.g., caspase-3, p53, and PON1) and signaling cascades (e.g., Nrf2/HO-1 pathway). This review highlights that CoQ10 may be a potential strategy in the treatment of AKI.

A novel anti-atherosclerotic mechanism of quercetin: Competitive binding to KEAP1 via Arg483 to inhibit macrophage pyroptosis

Natural antioxidants represented by quercetin have been documented to be effective against atherosclerosis. However, the related mechanisms remain largely unclear. In this study, we identified a novel anti-atherosclerotic mechanism of quercetin inhibiting macrophage pyroptosis by activating NRF2 through binding to the Arg483 site of KEAP1 competitively. In ApoE-/- mice fed with high fat diet, quercetin administration attenuated atherosclerosis progression by reducing oxidative stress level and suppressing macrophage pyroptosis. At the cellular level, quercetin suppressed THP-1 macrophage pyroptosis induced by ox-LDL, demonstrated by inhibiting NLRP3 inflammasome activation and reducing ROS level, while these effects were reversed by the specific NRF2 inhibitor (ML385). Mechanistically, quercetin promoted NRF2 to dissociate from KEAP1, enhanced NRF2 nuclear translocation as well as transcription of downstream antioxidant protein. Molecular docking results suggested that quercetin could bind with KEAP1 at Arg415 and Arg483. In order to verify the binding sites, KEAP1 mutated at Arg415 and Arg483 to Ser (R415S and R483S) was transfected into THP-1 macrophages, and the anti-pyroptotic effect of quercetin was abrogated by Arg483 mutation, but not Arg415 mutation. Furthermore, after administration of adeno associated viral vector (AAV) with AAV-KEAP1-R483S, the anti-atherosclerotic effects of quercetin were almost abolished in ApoE-/- mice. These findings proved quercetins suppressed macrophage pyroptosis by targeting KEAP1/NRF2 interaction, and provided reliable data on the underlying mechanism of natural antioxidants to protect against atherosclerosis.

Silymarin abrogates acrylamide-induced oxidative stress-mediated testicular toxicity via modulation of antioxidant mechanism, DNA damage, endocrine deficit and sperm quality in rats

Acrylamide (ACR) is a toxic chemical formed in foods processed at high temperature; it is a food-borne toxicant with increasing public health attention due to its carcinogenic, neurotoxic and reproductive toxicities. However, till date, it is unknown whether silymarin (SIL) could attenuate ACR testicular toxicity. Therefore, the present study investigated the effect of SIL on ACR testiculotoxicity in rats. Rats were randomly divided and administered respective agents in Control group, ACR group, SIL group and ACR + SIL group for consecutive 14 days. Rat exposure to ACR resulted in significant reduction in the level of serum testosterone, whereas FSH and LH levels prominently increased compared to control. Acrylamide induced marked decreases in sperm count and sperm motility followed by a considerable increase in sperm abnormality percentage in the ACR-exposed rats in comparison to control. The testicular activities of glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD) were significantly diminished, whereas malondialdehyde (MDA) level considerably increased. Additionally, ACR induced marked DNA fragmentation and histopathological lesions compared to control. Interestingly, the co-treatment of SIL with ACR attenuated the altered reproductive indices and restored antioxidant balance and DNA integrity. Overall, SIL prevents ACR-induced testicular reproductive deficits via modulation of antioxidant mechanism in rats.

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

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

Antioxidant Effects of Irisin in Liver Diseases: Mechanistic Insights

Oxidative stress is a crucial factor in the development of various liver diseases. Irisin, a metabolic hormone discovered in 2012, is mainly produced by proteolytic cleavage of fibronectin type III domain containing 5 (FNDC5) in skeletal muscles. Irisin is induced by physical exercise, and a rapidly growing body of literature suggests that irisin is, at least partially, responsible for the beneficial effects of regular exercise. The major biological function of irisin is believed to be involved in the maintenance of metabolic homeostasis. However, recent studies have suggested the therapeutic potential of irisin against a variety of liver diseases involving its antioxidative function. In this review, we aim to summarize the accumulating evidence demonstrating the antioxidative effects of irisin in liver diseases, with an emphasis on the current understanding of the potential molecular mechanisms.

Chlorogenic acid protects human chondrocyte C28/I2 cells from oxidative stress-induced cell death through activation of autophagy

AIMS

The development of osteoarthritis (OA), the most common form of arthritis, is commonly associated with oxidative stress. Indeed, the lack of antioxidant responses largely increases OA incidence. OA is a leading cause of disability in the elderly, which reduces the quality of life and places high socioeconomic burdens on them. Several polyphenolic compounds, including chlorogenic acid (CGA), have shown cytoprotective effects via their antioxidant activity, but the exact mechanism (s) remain elusive. In this study, we demonstrated how CGA protects human chondrocytes against H₂O₂-induced apoptosis.

MATERIALS AND METHODS

The cytoprotective effect by CGA in 500 μM hydrogen peroxide-treated C28/I2 cells was evaluated by cell viability, TUNEL assay, and Western blotting analyses, and autophagy assessment was further performed by AO and MDC staining and tandem mRFP-GFP fluorescence analyses.

KEY FINDINGS

Treatment of CGA to the human chondrocytes under oxidative stress significantly decreased apoptosis markers, such as cleaved caspase 3 and cleaved PARP, and increased anti-apoptotic marker Bcl-xL and the antioxidant response proteins NRF2 and NF-κB. Furthermore, CGA-dependent activation of antioxidant response proteins NRF2 and NF-κB and its protective effects in chondrocytes depended on autophagy. Indeed, CGA treatment and autophagy induction significantly decreased reactive oxygen species (ROS)-induced apoptosis.

SIGNIFICANCE

CGA exhibited the protective effect to human chondrocyte C28/I2 cells against oxidative stress-induced cell death by activating autophagy. These findings indicate that CGA is a potential therapeutic agent for the development of OA drugs.

Caffeoylquinic acids: chemistry, biosynthesis, occurrence, analytical challenges, and bioactivity

Caffeoylquinic acids (CQAs) are specialized plant metabolites we encounter in our daily life. Humans consume CQAs in mg-to-gram quantities through dietary consumption of plant products. CQAs are considered beneficial for human health, mainly due to their anti-inflammatory and antioxidant properties. Recently, new biosynthetic pathways via a peroxidase-type p-coumaric acid 3-hydroxylase enzyme were discovered. More recently, a new GDSL lipase-like enzyme able to transform monoCQAs into diCQA was identified in Ipomoea batatas. CQAs were recently linked to memory improvement; they seem to be strong indirect antioxidants via Nrf2 activation. However, there is a prevalent confusion in the designation and nomenclature of different CQA isomers. Such inconsistencies are critical and complicate bioactivity assessment since different isomers differ in bioactivity and potency. A detailed explanation regarding the origin of such confusion is provided, and a recommendation to unify nomenclature is suggested. Furthermore, for studies on CQA bioactivity, plant-based laboratory animal diets contain CQAs, which makes it difficult to include proper control groups for comparison. Therefore, a synthetic diet free of CQAs is advised to avoid interferences since some CQAs may produce bioactivity even at nanomolar levels. Biotransformation of CQAs by gut microbiota, the discovery of new enzymatic biosynthetic and metabolic pathways, dietary assessment, and assessment of biological properties with potential for drug development are areas of active, ongoing research. This review is focused on the chemistry, biosynthesis, occurrence, analytical challenges, and bioactivity recently reported for mono-, di-, tri-, and tetraCQAs.