Hepatoprotective and free radical scavenging actions of quercetin nanoparticles on aflatoxin B1-induced liver damage: in vitro/in vivo studies

Therapeutic detoxification of quercetin for aflatoxin B1-related toxicity: Roles of oxidative stress, inflammation, and metabolic enzymes

Aflatoxins (AFTs), a type of mycotoxin mainly produced by Aspergillus parasiticus and Aspergillus flavus, could be detected in food, feed, Chinese herbal medicine, grain crops and poses a great threat to public health security. Among them, aflatoxin B1 (AFB1) is the most toxic one. Exposure to AFB1 poses various health risks to both humans and animals, including the development of chronic inflammatory diseases, cardiovascular diseases, neurodegenerative diseases, and cancer. The molecular mechanisms underlying these risks are intricate and dependent on specific contexts. This review primarily focuses on summarizing the protective effects of quercetin, a natural phenolic compound, in mitigating the toxic effects induced by AFB1 in both in vitro experiments and animal models. Additionally, the review explores the molecular mechanisms that underlie these protective effects. Quercetin has been demonstrated to not only have the direct inhibitory action on the production of AFTs from Aspergillus, both also possess potent ameliorative effects against AFB1-induced cytotoxicity, hepatotoxicity, and neurotoxicity. These effects are attributed to the inhibition of oxidative stress, mitochondrial dysfunction, mitochondrial apoptotic pathway, and inflammatory response. It could also directly target several metabolic enzymes (i.e., CYP3As and GSTA1) to reduce the production of toxic metabolites of AFB1 within cells, then reduce AFB1-induced cytotoxicity. In conclusion, this review highlights quercetin is a promising detoxification agent for AFB1. By advancing our understanding of the protective mechanisms offered by quercetin, we aim to contribute to the development of effective detoxification agents against AFB1, ultimately promoting better health outcomes.

Therapeutic Effect of Natural Products and Dietary Supplements on Aflatoxin-Induced Nephropathy

Aflatoxins are harmful natural contaminants found in foods and are known to be hepatotoxic. However, recent studies have linked chronic consumption of aflatoxins to nephrotoxicity in both animals and humans. Here, we conducted a systematic review of active compounds, crude extracts, herbal formulations, and probiotics against aflatoxin-induced renal dysfunction, highlighting their mechanisms of action in both in vitro and in vivo studies. The natural products and dietary supplements discussed in this study alleviated aflatoxin-induced renal oxidative stress, inflammation, tissue damage, and markers of renal function, mostly in animal models. Therefore, the information provided in this review may improve the management of kidney disease associated with aflatoxin exposure and potentially aid in animal feed supplementation. However, future research is warranted to translate the outcomes of this study into clinical use in kidney patients.

Some relevant mitigating agents of chronic aflatoxin exposure: a treatise

Aflatoxins, a group of toxic secondary metabolites produced by Aspergillus species, pose significant threats to human health due to their potent carcinogenic, mutagenic, and immunosuppressive properties. Chronic exposure to these contaminants, commonly found in staple foods such as maize and groundnuts, has been linked to an increased risk of liver cancer, growth impairment, and immune dysfunction. Several agents, such as calcium montmorillonite clay and Lactobacillus rhamnosus GG, have shown promise in reducing aflatoxin bioavailability and alleviating its toxic effects. Additionally, dietary supplements such as chlorophyllin, selenium, and N-acetylcysteine have demonstrated potential as adjuvants to counteract aflatoxin-induced oxidative stress and support liver function. In this treatise, some of the most discussed approaches to mitigating aflatoxin effects are explored in terms of their efficacy, safety, and potential mechanisms of action, which include direct aflatoxin binding, detoxification, cellular antioxidative, and hepatocellular protection properties. However, the effectiveness of these strategies can be influenced by various factors, such as dose, duration of exposure, and individual susceptibility. Therefore, further research is needed to optimize these interventions and develop new, targeted therapies for the prevention and treatment of aflatoxin-related diseases. This review aims to provide a comprehensive analysis of 18 pharmaceutical, nutraceutical, supplement, and probiotic strategies currently available for mitigating the deleterious effects of chronic aflatoxin exposure in humans and animal models.

Application of Nanomaterials in the Production of Biomolecules in Microalgae: A Review

Nanomaterials (NMs) are becoming more commonly used in microalgal biotechnology to empower the production of algal biomass and valuable metabolites, such as lipids, proteins, and exopolysaccharides. It provides an effective and promising supplement to the existing algal biotechnology. In this review, the potential for NMs to enhance microalgal growth by improving photosynthetic utilization efficiency and removing reactive oxygen species is first summarized. Then, their positive roles in accumulation, bioactivity modification, and extraction of valuable microalgal metabolites are presented. After the application of NMs in microalgae cultivation, the extracted metabolites, particularly exopolysaccharides, contain trace amounts of NM residues, and thus, the impact of these residues on the functional properties of the metabolites is also evaluated. Finally, the methods for removing NM residues from the extracted metabolites are summarized. This review provides insights into the application of nanotechnology for sustainable production of valuable metabolites in microalgae and will contribute useful information for ongoing and future practice.

Cellular and molecular mechanisms of aflatoxin B1-mediated neurotoxicity: The therapeutic role of natural bioactive compounds

Aflatoxin B1 (AFB1), a dietary toxin from the mold Aspergillus species, is well acknowledged to elicit extra-hepatic toxicity in both animals and humans. The neurotoxicity of AFB1 has become a global public health concern. Contemporary research on how AFB1 enters the brain to elicit neuronal dysregulation leading to noxious neurological outcomes has increased greatly in recent years. The current review discusses several neurotoxic outcomes and susceptible targets of AFB1 toxicity at cellular, molecular and genetic levels. Specifically, neurotoxicity studies involving the use of brain homogenates, neuroblastoma cell line IMR-32, human brain microvascular endothelial cells, microglial cells, and astrocytes, as well as mammalian and non-mammalian models to unravel the mechanisms associated with AFB1 exposure are highlighted. Further, some naturally occurring bioactive compounds with compelling therapeutic effects on AFB1-induced neurotoxicity are reviewed. In conclusion, available data from literature highlight AFB1 as a neurotoxin and its possible pathological contribution to neurological disorders. Further mechanistic studies aimed at discovering and developing effective therapeutics for AFB1 neurotoxicity is warranted.

Quercetin attenuates angiotensin II-induced proliferation of vascular smooth muscle cells and p53 pathway activation in vitro and in vivo

Quercetin is an essential flavonoid mostly found in herbal plants, fruits, and vegetables, which exhibits anti-hypertension properties. However, its pharmacological impact on angiotensin II (Ang II) induced the increase of blood pressure along with in-depth mechanism needs further exploration. The present study pointed out the anti-hypertensive role of quercetin and its comprehensive fundamental mechanisms. Our data showed that quercetin treatment substantially reduced the increase in blood pressure, pulse wave velocity, and aortic thickness of abdominal aorta in Ang II-infused C57BL/6 mice. RNA sequencing revealed that quercetin treatment reversed 464 differentially expressed transcripts in the abdominal aorta of Ang II-infused mice. Moreover, overlapping KEGG-enriched signaling pathways identified multiple common pathways between the comparison of Ang II versus control and Ang II + quercetin versus Ang II. Likewise, these pathways included cell cycle as well as p53 pathways. Transcriptome was further validated by immunohistochemistry, indicating that quercetin treatment significantly decreased the Ang II-induced expression of proliferating cell nuclear antigen (PCNA), cyclin-dependent kinase-4 (CDK4), and cyclin D1, while increased protein expression of p53, and p21 in abdominal aortic tissues of mice. In vitro, quercetin treatment meaningfully decreased the cell viability, arrested cell cycle at G0/G1 phase, and up-regulated the p53 and p21 proteins expression, as well as down-regulated the protein expression of cell cycle-related markers, for example, CDK4, cyclin D1 in Ang II stimulated vascular smooth muscle cells (VSMCs). This study addresses pharmacologic and mechanistic perspectives of quercetin against Ang-II-induced vascular injury and the increase of blood pressure.

Antifungal Activity of Juglans-regia-Mediated Silver Nanoparticles (AgNPs) against Aspergillus-ochraceus-Induced Toxicity in In Vitro and In Vivo Settings

Aflatoxins produced by some species of Aspergillus are considered secondary toxic fungal by-products in feeds and food. Over the past few decades, many experts have focused on preventing the production of aflatoxins by Aspergillus ochraceus and also reducing its toxicity. Applications of various nanomaterials in preventing the production of these toxic aflatoxins have received a lot of attention recently. The purpose of this study was to ascertain the protective impact of Juglans-regia-mediated silver nanoparticles (AgNPs) against Aspergillus-ochraceus-induced toxicity by exhibiting strong antifungal activity in in vitro (wheat seeds) and in vivo (Albino rats) settings. For the synthesis of AgNPs, the leaf extract of J. regia enriched with high phenolic (72.68 ± 2.13 mg GAE/g DW) and flavonoid (18.89 ± 0.31 mg QE/g DW) contents was used. Synthesized AgNPs were characterized by various techniques, including TEM, EDX, FT-IR, and XRD, which revealed that the particles were spherical in shape with no agglomeration and fine particle size in the range of 16-20 nm. In vitro antifungal activity of AgNPs was tested on wheat grains by inhibiting the production of toxic aflatoxins by A. ochraceus. According to the results obtained from High-Performance Liquid Chromatography (HPLC) and Thin-Layer Chromatography (TLC) analyses, there was a correlation between the concentration of AgNPs and a decrease in the production of aflatoxin G1, B1, and G2. For in vivo antifungal activity, Albino rats were administrated with different doses of AgNPs in five groups. The results indicated that the feed concentration of 50 µg/kg feed of AgNPs was more effective in improving the disturbed levels of different functional parameters of the liver (alanine transaminase (ALT): 54.0 ± 3.79 U/L and aspartate transaminase (AST): 206 ± 8.69 U/L) and kidney (creatinine 0.49 ± 0.020 U/L and BUN 35.7 ± 1.45 U/L), as well as the lipid profile (LDL 22.3 ± 1.45 U/L and HDL 26.3 ± 2.33 U/L). Furthermore, the histopathological analysis of various organs also revealed that the production of aflatoxins was successfully inhibited by AgNPs. It was concluded that the harmful effects of aflatoxins produced by A. ochraceus can be successfully neutralized by using J. regia-mediated AgNPs.

Protective efficacy of luteolin against aflatoxinB1-induced toxicity, oxidative damage, and apoptosis in the rat liver

One particularly harmful mycotoxin, aflatoxin B1 (AFB₁), usually triggers liver toxicity and oxidative stress in both humans and other mammals. Luteolin (LUTN), a popular active phytochemical molecule, exhibits a strong antioxidant potential. The purpose of this investigation was to explore the potential molecular mechanism in rats and determine if LUTN exhibits protective benefits against AFB₁-induced hepatotoxicity. Random selection was used to determine the four treatment groups, each consisting of 24 rats (n = 6). Physiological saline was administered to group 1 (CONT); group 2 received LUTN for a dosage of 50-mg/kg BW. AFB₁ was administered to group 3 for a dosage of 0.75-mg/kg BW, and AFB₁ with LUTN was given to group 4 at the same dosages mentioned in the previous groups. Rats intoxicated with AFB₁ alterations of hepatic transaminases, aspartate aminotransferase (AST) and alanine aminotransferase (ALT), displayed periportal mononuclear cell infiltrations, disorganized lobular architecture, and dispersed necrotic cells in their liver tissues. By reducing serum biochemical levels of the hepatic transaminases ALT and AST brought on by AFB₁ exposure, our results demonstrated that LUTN treatment considerably restored liver injury. Through lowering the production of malondialdehyde (MDA) and reactive oxygen species (ROS), as well as by boosting the activity of the antioxidant enzyme catalase (CAT) and superoxide dismutase (SOD), LUTN mitigated the oxidative stress brought on by AFB₁. Our findings showed that LUTN significantly reversed the liver damage caused by AFB₁. When considered as a whole, LUTN may protect the liver from damage brought on by AFB₁ by acting as a potential mitigator and may aid in the creation of cutting-edge therapies to treat liver illnesses in humans and/or animals.

Hepatic-Targeted Nano-enzyme with Resveratrol Loading for Precise Relief of Nonalcoholic Steatohepatitis

Nonalcoholic steatohepatitis (NASH) is characterized by massive lipid deposition in hepatocytes and is often associated with hepatic inflammation and other severe metabolic syndromes. The intervention of NASH can prevent its further progression into hepatocarcinoma. In this study we have successfully constructed liver-targeted Ce-based hollow mesoporous nanocarriers loaded with bioactive drugs. This may provide an effective approach for eliminating NASH. Liver-section-specific targeting was realized by covalently linked galactose (Gal), which can be specifically recognized by receptors in the membranes of hepatocytes. Meanwhile, resveratrol (Res), a drug used to treat NASH, was efficiently loaded into the pores and cavity of CeO₂ (Res@H-CeO₂ -Gal). In steatotic HepG2 cells (free fatty acid induction), this nanosystem was found to enhance cellular Res internalization for improved anti-lipogenesis activity. In mice with NASH, Res@H-CeO₂ -Gal increased Res delivery to liver sections for a reduction in lipid accumulation and enhanced anti-inflammatory activity from the antioxidant capacity of Ce-based nanocarriers. This effectively recovered NASH mice to the normal state. These findings show that the hepatic targeting and Res delivery nanoplatform could act as a safe and promising strategy for the elimination of NASH and other liver diseases.

Dental Implants and Implant Coatings: A Focus on Their Toxicity and Safety

Dental implants are medical devices that are surgically inserted into the patient's jawbone by an orthodontist to act as roots of missing teeth. After the implantation, the maxilla or mandible integrates with the surface of the dental implant. This process, called "osseointegration," is an important period to ensure the long-term use of dental implants and prevent implant failures. Metal implants are the most used implant materials. However, they have disadvantages such as corrosion, metal ion release from metal implant surfaces and associated toxicity. To avoid these adverse effects and improve osseointegration, alternative dental implant materials such as ceramics, polymers, composites, and novel surface modification technologies have been developed. The safety of these materials are also of concern for toxicologists. This review will give general information about dental implant materials, osseointegration and successful implantation process. Moreover, we will focus on the new surface coatings materials for of dental implants and their toxicity and safety concerns will be discussed.

The Dual Role of Oxidative-Stress-Induced Autophagy in Cellular Senescence: Comprehension and Therapeutic Approaches

The contemporary lifestyle of the last decade has undeniably caused a tremendous increase in oxidative-stress-inducing environmental sources. This phenomenon is not only connected with the rise of ROS levels in multiple tissues but is also associated with the induction of senescence in different cell types. Several signaling pathways that are associated with the reduction in ROS levels and the regulation of the cell cycle are being activated, so that the organism can battle deleterious effects. Within this context, autophagy plays a significant role. Through autophagy, cells can maintain their homeostasis, as if it were a self-degradation process, which removes the "wounded" molecules from the cells and uses their materials as a substrate for the creation of new useful cell particles. However, the role of autophagy in senescence has both a "dark" and a "bright" side. This review is an attempt to reveal the mechanistic aspects of this dual role. Nanomedicine can play a significant role, providing materials that are able to act by either preventing ROS generation or controllably inducing it, thus functioning as potential therapeutic agents regulating the activation or inhibition of autophagy.

Stability and Function of Extracellular Vesicles Derived from Immortalized Human Corneal Stromal Stem Cells: A Proof of Concept Study

With significant advancement and development of extracellular vesicle (EV)-based therapies, there is a growing need to understand how their storage affects their physical and functional characteristics. EVs were isolated from the conditioned medium of a corneal stromal stem cell line (imCSSC) using Total Exosome isolation kit (TEI) and ultracentrifugation (UC) combined protocol. Purified EVs were stored at 4°C, - 80°C, room temperature (RT) after lyophilization with or without trehalose for 4 weeks. EVs stored at - 80°C and RT (lyophilization with trehalose) demonstrated a comparable morphology, while the freeze-dried samples without trehalose showed aggregation and degradation under a transmission electron microscope (TEM). Lyophilized samples without trehalose demonstrated a decreased particle concentration, recovery rate and protein concentration, which was remediated by the addition of trehalose. EVs stored at - 80℃ showed no change in the protein expression of CD9, CD63, and CD81. Regardless of the storage condition, all EV samples investigated reduced inflammation, as well as inhibited expression of fibrotic markers in vitro. Lyophilization of EVs with trehalose was a feasible storage method that retained the physical property and in vitro biological activities of EVs after 4 weeks of storage, while - 80°C offered the best retention of imCSSC-derived EV physical properties. For the first time, this data demonstrated a practical and translatable method for the storage of CSSC-derived EVs for clinical use.

Quercetin Protected from Aluminum Phosphide-induced Acute and Subacute Cardio- and Hepatotoxicity in Rats

BACKGROUND

Aluminum phosphide (ALP) intoxication either accidentally or intentionally, is one of the major health concerns in developing countries. Its poisoning causes severe damage to organs including the heart and liver.

OBJECTIVES

This study aimed to investigate the hepato- and cardioprotective effects of quercetin (QCN) on the acute/subacute toxicity of ALP in rodent models.

METHODS

Acute (single dose, 12.5 mg/kg, orally) and subacute (2 mg/kg, orally and 7 days) intoxication of ALP were induced in rats and the protective effects of QCN on altered hepatic/cardiac functional enzyme concentrations, myeloperoxidase activity, oxidative stress biomarkers, and histopathological changes were studied at three doses of 10, 50 and 100 mg/kg BW. To record any heart abnormality, an electrocardiogram (ECG) was recorded 3 h after the last treatment.

RESULTS

Quercetin reduced the ALP-increased hepatic and cardiac functional enzyme concentrations and myeloperoxidase activity. Moreover, QCN improved remarkably the ALP-induced ECG abnormalities (T inversion, bigeminy in R waves) and arrhythmias. QCN attenuated significantly (p < 0.05) the ALP-induced oxidative/ nitrosative stress and histopathological injuries in the liver and heart.

CONCLUSION

Our results suggest that QCN is able to protect the ALP-induced cardiac and hepatic injuries in both acute and subacute models and its effects attribute to its antioxidant and anti-inflammatory properties.

May phytophenolics alleviate aflatoxins-induced health challenges? A holistic insight on current landscape and future prospects

The future GCC-connected environmental risk factors expedited the progression of nCDs. Indeed, the emergence of AFs is becoming a global food security concern. AFs are lethal carcinogenic mycotoxins, causing damage to the liver, kidney, and gastrointestinal organs. Long-term exposure to AFs leads to liver cancer. Almost a variety of food commodities, crops, spices, herbaceous materials, nuts, and processed foods can be contaminated with AFs. In this regard, the primary sections of this review aim to cover influencing factors in the occurrence of AFs, the role of AFs in progression of nCDs, links between GCC/nCDs and exposure to AFs, frequency of AFs-based academic investigations, and world distribution of AFs. Next, the current trends in the application of PPs to alleviate AFs toxicity are discussed. Nearly, more than 20,000 published records indexed in scientific databases have been screened to find recent trends on AFs and application of PPs in AFs therapy. Accordingly, shifts in world climate, improper infrastructures for production/storage of food commodities, inconsistency of global polices on AFs permissible concentration in food/feed, and lack of the public awareness are accounting for a considerable proportion of AFs damages. AFs exhibited their toxic effects by triggering the progression of inflammation and oxidative/nitrosative stress, in turn, leading to the onset of nCDs. PPs could decrease AFs-associated oxidative stress, genotoxic, mutagenic, and carcinogenic effects by improving cellular antioxidant balance, regulation of signaling pathways, alleviating inflammatory responses, and modification of gene expression profile in a dose/time-reliant fashion. The administration of PPs alone displayed lower biological properties compared to co-treatment of these metabolites with AFs. This issue might highlight the therapeutic application of PPs than their preventative content. Flavonoids such as quercetin and oxidized tea phenolics, curcumin and resveratrol were the most studied anti-AFs PPs. Our literature review clearly disclosed that considering PPs in antioxidant therapies to alleviate complications of AFs requires improvement in their bioavailability, pharmacokinetics, tissue clearance, and off-target mode of action. Due to the emergencies in the elimination of AFs in food/feedstuffs, further large-scale clinical assessment of PPs to decrease the consequences of AFs is highly required.

Progress on the detoxification of aflatoxin B1 using natural anti-oxidants

Aflatoxins are toxic secondary metabolites produced by Aspergillus fungi. The most toxic among them is Aflatoxin B1 (AFB1) which is known to have genotoxic, immunotoxic, teratogenic, carcinogenic, and mutagenic toxic effects (amongst others). The mechanisms responsible for its toxicity include the induction of oxidative stress, cytotoxicity, and DNAdamage. Studies have found that natural anti-oxidants can reduce the damage that AFB1 inflicts on the body by alleviating oxidative stress and inhibiting the biotransformation of AFB1. Therefore, this review outlines the latest progress in research on the use of natural anti-oxidants as antidotes to aflatoxin poisoning and their detoxification mechanisms. It also considers the problems that may possibly arise from their use and their application prospects. Our aim is to provide a useful reference for the prevention and treatment of AFB1 poisoning.

Galangin Nanoparticles Protect Acetaminophen-Induced Liver Injury: A Biochemical and Histopathological Approach

One of the main causes of acute liver failure is overdose with acetaminophen. Excessive consumption of acetaminophen leads to the production of NAPQI (N-acetyl-p-benzoquinone imine) through the activity of the enzyme cytochrome c oxidase. For this purpose, the effect of galangin nanoparticles with antioxidant activities will be evaluated for the treatment of acetaminophen-induced hepatotoxicity. In this study, after the synthesis of galangin nanoparticles and particle size determination, mice were divided into six groups. Before treatment, a single dose (350 mg/kg) of acetaminophen was administered by gavage in all groups. The activity of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), as well as biochemical factors FRAP and MDA in serum were measured and a histopathological study was performed. The prepared nanoparticles produced in this research were characterized by the SEM, DLS, and ZETA potential, and the average particle size was obtained in the range of 150 nm. Serum levels of liver enzymes (AST and ALT) in the nanoparticle group decreased significantly compared with the control group ( $P<0.05$ ). In the group without treatment, the activity of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) enzymes increased significantly compared with the treatment groups. Also, galangin nanoparticles, at a dose of 20 mg/kg, improve cell damage in hepatocytes and preserve the tissue structure of the liver. Galangin nanoparticles reduce the acetaminophen-induced hepatotoxicity by reducing the number of liver function indices. According to our findings, the liver-protective effects of the nanoparticle may be due to its antioxidant properties.

Engineered exosome-mediated delivery of circDIDO1 inhibits gastric cancer progression via regulation of MiR-1307-3p/SOCS2 Axis

Background

Our previous study has identified a novel circRNA (circDIDO1) that is down-regulated in gastric cancer (GC) and significantly inhibits GC progression. The purpose of this study is to identify the molecular mechanism for circDIDO1 and to evaluate the therapeutic effect of circDIDO1 in GC.

Methods

By combining bioinformatic analysis with RNA sequencing data, we predicted the potential target of circDIDO1 and further validated the regulatory mechanisms for its tumor suppressor function in GC. RIP assay, luciferase reporter assay and in vitro cell function assays were performed to analyze circDIDO1-regulated downstream target genes. For the therapeutic study, circDIDO1-loaded, RGD-modified exosomes (RGD-Exo-circDIDO1) were constructed and its anti-tumor efficacy and biological safety were evaluated in vitro and in vivo.

Results

CircDIDO1 inhibited GC progression by regulating the expression of the signal transducer inhibitor SOSC2 through sponging miR-1307-3p. Overexpression of circDIDO1 or SOSC2 antagonized the oncogenic role of miR-1307-3p. RGD-Exo-circDIDO1 could efficiently deliver circDIDO1 to increase SOCS2 expression in GC cells. Compared with PBS and RGD-Exo-vector treatment, RGD-Exo-circDIDO1 treatment significantly inhibited the proliferation, migration and invasion of GC cells while promoted cell apoptosis. The therapeutic efficacy of RGD-Exo-circDIDO1 was further confirmed in a mouse xenograft tumor model. In addition, major tissues including the heart, liver, spleen, lungs and kidneys showed no obvious histopathological abnormalities or lesions in the RGD-Exo-circDIDO1 treated group.

Conclusion

Our findings revealed that circDIDO1 suppressed the progression of GC via modulating the miR-1307-3p/SOSC2 axis. Systemic administration of RGD modified, circDIDO1 loaded exosomes repressed the tumorigenicity and aggressiveness of GC both in vitro and in vivo, suggesting that RGD-Exo-circDIDO1 could be used as a feasible nanomedicine for GC therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03527-z.

Design and Synthesis of Multipotent Antioxidants for Functionalization of Iron Oxide Nanoparticles

Multipotent antioxidants (MPAO) were synthesized and characterized by FTIR, NMR. The functionalized nanoparticles (IONP@AO) were characterized by FTIR, XRD, Raman, HRTEM, FESEM, VSM, and EDX. IONP@AO1 and IONP@AO2 have average particles size of 10 nm and 11 nm, respectively. The functionalized IONP@AO has a superparamagnetic nature, with saturation magnetization of 45 emu·g−1. Structure-based virtual screening of the designed MPAO was performed by PASS analysis and ADMET studies to discover and predict the molecule’s potential bioactivities and safety profile before the synthesis procedure. The half-maximal inhibitory concentration (IC50) of DPPH analysis results showed a four-fold decrease in radical scavenging by IONP@AO compared to IONP. In addition to antioxidant activity, IONP@AO showed suitable antimicrobial activities when tested on various bacterial and fungal strains. The advantage of the developed nanoantioxidants is that they have a strong affinity towards biomolecules such as enzymes, proteins, amino acids, and DNA. Thus, synthesized nanoantioxidants can be used to develop biomedicines that can act as antioxidant, antimicrobial, and anticancer agents.

Surface Functionalization of Magnetite Nanoparticles with Multipotent Antioxidant as Potential Magnetic Nanoantioxidants and Antimicrobial Agents

Functionalized magnetite nanoparticles (Fe₃O₄) were prepared using the coprecipitation method followed by functionalization with a multipotent antioxidant (MPAO). The MPAO was synthesized and analyzed using FTIR and NMR techniques. In this study, the functionalized nanoparticles (IONP@AO) were produced and evaluated using the FTIR, XRD, Raman, HRTEM, FESEM, VSM, and EDX techniques. The average determined particle size of IONP@AO was 10 nanometers. In addition, it demonstrated superparamagnetic properties. The magnitude of saturation magnetization value attained was 45 emu g⁻¹. Virtual screenings of the MPAO’s potential bioactivities and safety profile were performed using PASS analysis and ADMET studies before the synthesis step. For the DPPH test, IONP@AO was found to have a four-fold greater ability to scavenge free radicals than unfunctional IONP. The antimicrobial properties of IONP@AO were also demonstrated against a variety of bacteria and fungi. The interaction of developed nanoantioxiants with biomolecules makes it a broad-spectrum candidate in biomedicine and nanomedicine.

Quercetin Reduces Oxidative Stress and Apoptosis by Inhibiting HMGB1 and Its Translocation, Thereby Alleviating Liver Injury in ACLF Rats

Background

Acute on chronic liver failure (ACLF) is a syndrome of acute liver failure that occurs on the basis of chronic liver disease, which is characterized by a rapid deterioration in a short period and high mortality. High mobility group box 1 (HMGB1) may be involved in the pathological process of ACLF; its specific role remains to be further elucidated. Our previous studies have shown that quercetin (Que) exerts anti-oxidant and anti-apoptotic effects by inhibiting HMGB1 in vitro. The present study aimed to investigate the effect of Que on liver injury in ACLF rats.

Methods

The contents of ALT, AST, TBiL, and PT time of rats in each group were observed. HE staining was used to detect liver pathology. The levels of oxidative stress indicators such as MDA, GSH, and 4-HNE in the rat liver were detected. TUNEL assay was used to detect apoptosis in rat hepatocytes. Immunofluorescence and western blot analysis were performed to explore the protective effect of Que on ACLF rats and the underlying mechanism.

Results

The results showed that Que could reduce the increase of serum biochemical indices, improve liver pathology, and reduce liver damage in ACLF rats. Further results confirmed that Que reduced the occurrence of oxidative stress and apoptosis of hepatocytes, and these reactions may aggravate the progress of ACLF. Meanwhile, the results of immunofluorescence and western blotting also confirmed that the expression of HMGB1 and extranuclear translocation in ACLF rat hepatocytes were significantly increased, which was alleviated by the treatment of Que. In addition, when cotreated with glycyrrhizin (Gly), an inhibitor of HMGB1, the inhibition of Que on HMGB1 and its translocation, apoptosis and oxidative stress, and the related proteins of HMGB1-mediated cellular pathway have been significantly enhanced.

Conclusion

Thus, Que alleviates liver injury in ACLF rats, and its mechanism may be related to oxidative stress and apoptosis caused by HMGB1 and its translocation.

Luteolin Alleviates AflatoxinB1-Induced Apoptosis and Oxidative Stress in the Liver of Mice through Activation of Nrf2 Signaling Pathway

Aflatoxin B₁ (AFB₁), a threatening mycotoxin, usually provokes oxidative stress and causes hepatotoxicity in animals and humans. Luteolin (LUTN), well-known as an active phytochemical agent, acts as a strong antioxidant. This research was designed to investigate whether LUTN exerts protective effects against AFB₁-induced hepatotoxicity and explore the possible molecular mechanism in mice. A total of forty-eight mice were randomly allocated following four treatment groups (n = 12): Group 1, physiological saline (CON). Group 2, treated with 0.75 mg/kg BW aflatoxin B₁ (AFB₁). Group 3, treated with 50 mg/kg BW luteolin (LUTN), and Group 4, treated with 0.75 mg/kg BW aflatoxin B₁ + 50 mg/kg BW luteolin (AFB₁ + LUTN). Our findings revealed that LUTN treatment significantly alleviated growth retardation and rescued liver injury by relieving the pathological and serum biochemical alterations (ALT, AST, ALP, and GGT) under AFB₁ exposure. LUTN ameliorated AFB₁-induced oxidative stress by scavenging ROS and MDA accumulation and boosting the capacity of the antioxidant enzyme (CAT, T-SOD, GSH-Px and T-AOC). Moreover, LUTN treatment considerably attenuates the AFB₁-induced apoptosis in mouse liver, as demonstrated by declined apoptotic cells percentage, decreased Bax, Cyt-c, caspase-3 and caspase-9 transcription and protein with increased Bcl-2 expression. Notably, administration of LUTN up-regulated the Nrf2 and its associated downstream molecules (HO-1, NQO1, GCLC, SOD1) at mRNA and protein levels under AFB₁ exposure. Our results indicated that LUTN effectively alleviated AFB₁-induced liver injury, and the underlying mechanisms were associated with the activation of the Nrf2 signaling pathway. Taken together, LUTN may serve as a potential mitigator against AFB₁-induced liver injury and could be helpful for the development of novel treatment to combat liver diseases in humans and/or animals.

Hepatotoxicity of food-borne mycotoxins: molecular mechanism, anti-hepatotoxic medicines and target prediction

Mycotoxins are metabolites produced by fungi. The widespread contamination of food and feed by mycotoxins is a global food safety problem and a serious threat to people's health. Most food-borne mycotoxins have strong hepatotoxicity. However, no effective methods have been found to prevent or treat Mycotoxin- Induced Liver Injury (MILI) in clinical and animal husbandry. In this paper, the molecular mechanisms and potential anti-MILI medicines of six food-borne MILI are reviewed, and their targets are predicted by network toxicology, which provides a theoretical basis for further study of the toxicity mechanism of MILI and the development of effective strategies to manage MILI-related health problems in the future and accelerate the development of food safety.

Orphan Nuclear Receptor RORγ Modulates the Genome-Wide Binding of the Cholesterol Metabolic Genes during Mycotoxin-Induced Liver Injury

Maintaining lipid homeostasis is crucial to liver function, the key organ that governs the whole-body energy metabolism. In contrast, lipid dysregulation has been implicated in mycotoxin-induced liver injury, by which the pathophysiological regulation and the molecular components involved remain elusive. Here we focused on the potential roles of orphan nuclear receptor (NR) RORγ in lipid programming, and aimed to explore its action on cholesterol regulation in the liver of mycotoxin-exposed piglets. We found that liver tissues were damaged in the mycotoxin-exposed piglets compared to the healthy controls, revealed by histological analysis, elevated seral ALT, AST and ALP levels, and increased caspase 3/7 activities. Consistent with the transcriptomic finding of down-regulated cholesterol metabolism, we demonstrated that both cholesterol contents and cholesterol biosynthesis/transformation gene expressions in the mycotoxin-exposed livers were reduced, including HMGCS1, FDPS, SQLE, EBP, FDFT1 and VLDLR. Furthermore, we reported that RORγ binds to the cholesterol metabolic genes in porcine hepatocytes using a genome-wide ChIP-seq analysis, whereas mycotoxin decreased the RORγ binding occupancies genome-wide, especially at the cholesterol metabolic pathway. In addition, we revealed the enrichment of co-factors p300 and SRC, the histone marks H3K27ac and H3K4me2, together with RNA Polymerase II (Pol-II) at the locus of HMGCS1 in hepatocytes, which were reduced by mycotoxin-exposure. Our results provide a deep insight into the cholesterol metabolism regulation during mycotoxin-induced liver injury, and propose NRs as therapeutic targets for anti-mycotoxin treatments.

N-acetyl cysteine treatment mitigates biomarkers of oxidative stress in different tissues of bile duct ligated rats

Cholestasis is a multifaceted clinical complication. Obstructive jaundice induced by bile duct ligation (BDL) is known as an animal model to investigate cholestasis and its associated complications. N-acetyl cysteine (NAC) is an antioxidant, radical scavenger, and thiol reductant widely investigated for its cytoprotective properties. The current investigation was designed to evaluate the role of NAC treatment on biomarkers of oxidative stress and organ histopathological alterations in a rat model of cholestasis/cirrhosis. BDL animals were supplemented with NAC (100 and 300 mg/kg, i.p, 42 consecutive days). Biomarkers of oxidative stress in the liver, brain, heart, skeletal muscle, lung, serum, and kidney tissue, as well as organ histopathological changes, were monitored. A significant increase in reactive oxygen species, lipid peroxidation, and protein carbonylation were detected in different tissues of BDL rats. Moreover, tissue antioxidant capacity was hampered, glutathione (GSH) reservoirs were depleted, and oxidized glutathione (GSSG) levels were significantly increased in the BDL group. Significant tissue histopathological alterations were evident in cirrhotic animals. It was found that NAC treatment (100 and 300 mg/kg, i.p) significantly mitigated biomarkers of oxidative stress and alleviated tissue histopathological changes in cirrhotic rats. These data represent NAC as a potential protective agent with therapeutic capability in cirrhosis and its associated complications.HIGHLIGHTSCholestasis is a multifaceted clinical complication that affects different organsOxidative stress plays a pivotal role in cholestasis-associated complicationsTissue antioxidant capacity is hampered in different tissues of cholestatic animalsAntioxidant therapy might play a role in the management of cholestasis-induced organ injuryNAC alleviated biomarkers of oxidative stress in cholestatic animalsNAC significantly improved tissues histopathological alterations in cholestatic rats.

Angiotensin receptor blocker Losartan inhibits tumor growth of colorectal cancer

The renin-angiotensin system (RAS) is up-regulated in patients with colorectal cancer (CRC) and is reported to be associated with poor prognosis and chemo-resistance. Here we explored the therapeutic potential of targeting RAS in CRC using Losartan, an angiotensin receptor blocker. An integrative-systems biology approach was used to explore a proteome-level dataset of a gene signature that is modulated by Losartan. The anti-proliferative activity of Losartan was evaluated using 2- and 3-dimensional cell culture models. A xenograft model of colon cancer was used to investigate tumor growth with Losartan alone and in combination with 5-FU followed by histological staining (Hematoxylin & Eosin and Masson trichrome staining), biochemical analyses, gene expression analyses by RT-PCR, western blot/IHC, or MMP Gelatin Zymography studies. Effects on cell cycle and cell death were assessed by flow cytometry. Losartan inhibited cell growth and suppressed cell cycle progression, causing an increase in CRC cells in the G1 phase. Losartan significantly reduced tumor growth and enhanced tumor cell necrosis. An impact on the inflammatory response, including up-regulation of pro-inflammatory cytokines and chemokines in CRC cells are potential mechanisms that could partially explain Losartan's anti-proliferative effects. Moreover, metastasis and angiogenesis were reduced in Losartan-treated mice as observed by inhibited matrix metalloproteinase-2 and -9 activities and decreased tumor vasculature. These data demonstrate the therapeutic potential of combining chemotherapeutic regimens with Losartan to synergistically enhance its activity and target the renin-angiotensin system as a new approach in colorectal cancer treatment.

Contamination of Aflatoxins Induces Severe Hepatotoxicity Through Multiple Mechanisms

Aflatoxins (AFs) are commonly contaminating mycotoxins in foods and medicinal materials. Since they were first discovered to cause “turkey X” disease in the United Kingdom in the early 1960s, the extreme toxicity of AFs in the human liver received serious attention. The liver is the major target organ where AFs are metabolized and converted into extremely toxic forms to engender hepatotoxicity. AFs influence mitochondrial respiratory function and destroy normal mitochondrial structure. AFs initiate damage to mitochondria and subsequent oxidative stress. AFs block cellular survival pathways, such as autophagy that eliminates impaired cellular structures and the antioxidant system that copes with oxidative stress, which may underlie their high toxicities. AFs induce cell death via intrinsic and extrinsic apoptosis pathways and influence the cell cycle and growth via microribonucleic acids (miRNAs). Furthermore, AFs induce the hepatic local inflammatory microenvironment to exacerbate hepatotoxicity via upregulation of NF-κB signaling pathway and inflammasome assembly in the presence of Kupffer cells (liver innate immunocytes). This review addresses the mechanisms of AFs-induced hepatotoxicity from various aspects and provides background knowledge to better understand AFs-related hepatoxic diseases.

Quercetin: Its Main Pharmacological Activity and Potential Application in Clinical Medicine

Quercetin is a flavonoid compound widely present in plants and exhibits a variety of biological activities. Research on quercetin has shown its potential for medical application. In this research, we elucidate its antioxidant mechanism and the broad-spectrum antibacterial and antiparasite properties; summarise its potential application in antioncology and cardiovascular protection and anti-immunosuppression treatment; and demonstrate its ability to alleviate the toxicity of mycotoxins. This research is expected to offer some insights and inspirations for the further study of quercetin, its properties, and the scientific basis for its better application in clinical practice.

Glycyrrhizin mediated liver-targeted alginate nanogels delivers quercetin to relieve acute liver failure

Acute liver failure is an uncommon and dramatic clinical syndrome with a high risk of mortality. Previous treatments existed some limitations of poor bioavailability and targeting the efficiency of drugs. In this study, a novel glycyrrhizin mediated liver-targeted alginate nanogels, which can deliver the antioxidant quercetin to the liver for the treatment of acute liver injury. In vitro radical scavenging results showed that the antioxidant activity of quercetin was increased 81-fold. The tissue distribution results indicated that glycyrrhizin-mediated nanogels showed stronger fluorescence intensity in the liver, which improved liver targeting and therapeutic efficacy. Quercetin-glycyrrhizin nanogels were more effective at restoring liver injury as indicated on serum markers, including alanine transaminase, aspartate aminotransferase, and total bilirubin. The histopathology result showed that quercetin-glycyrrhizin nanogels reversed liver damage. Oxidative parameters of malondialdehyde and glutathione s-transferase were decreased, which provided supporting evidence of antioxidation. Moreover, quercetin-glycyrrhizin nanogels were more effective in down-regulating the inflammation-related gene expression of tumor necrosis factor-α, interleukin-6, inducible nitric oxide synthase and monocyte chemotactic protein-1. In conclusion, the novel glycyrrhizin mediated liver-targeted alginate nanogels might be a promising treatment for acute liver failure.

Probing the Mechanism of Hepatotoxicity of Hexabromocyclododecanes through Toxicological Network Analysis

The prediction and mechanism analysis of hepatotoxicity of contaminants, because of their various phenotypes and complex mechanisms, is still a key problem in environmental research. We applied a toxicological network analysis method to predict the hepatotoxicity of three hexabromocyclododecane (HBCD) diastereoisomers (α-HBCD, β-HBCD, and γ-HBCD) and explore their potential mechanisms. First, we collected the hepatotoxicity related genes and found that those genes were significantly localized in the human interactome. Therefore, these genes form a disease module of hepatotoxicity. We also collected targets of α-, β-, and γ-HBCD and found that their targets overlap with the hepatotoxicity disease module. Then, we trained a model to predict hepatotoxicity of three HBCD diastereoisomers based on the relationship between the hepatotoxicity disease module and targets of compounds. We found that 593 genes were significantly located in the hepatotoxicity disease module (Z = 11.9, p < 0.001) involved in oxidative stress, cellular immunity, and proliferation, and the accuracy of hepatotoxicity prediction of HBCD was 0.7095 ± 0.0193 and the recall score was 0.8355 ± 0.0352. HBCD mainly affects the core disease module genes to mediate the adenosine monophosphate-activated kinase, p38MAPK, PI3K/Akt, and TNFα pathways to regulate the immune reaction and inflammation. HBCD also induces the secretion of IL6 and STAT3 to lead hepatotoxicity by regulating NR3C1. This approach is transferable to other toxicity research studies of environmental pollutants.

Taurine mitigates cirrhosis-associated heart injury through mitochondrial-dependent and antioxidative mechanisms

Cirrhosis-induced heart injury and cardiomyopathy is a serious consequence of this disease. It has been shown that bile duct ligated (BDL) animals could serve as an appropriate experimental model to investigate heart tissue injury in cirrhosis. The accumulation of cytotoxic chemicals (e.g., bile acids) could also adversely affect the heart tissue. Oxidative stress and mitochondrial impairment are the most prominent mechanisms of bile acid cytotoxicity. Taurine (Tau) is the most abundant non-protein amino acid in the human body. The cardioprotective effects of this amino acid have repeatedly been investigated. In the current study, it was examined whether mitochondrial dysfunction and oxidative stress are involved in the pathogenesis of cirrhosis-induced heart injury. Rats underwent BDL surgery. BDL animals received Tau (50, 100, and 500 mg/kg, i.p.) for 42 consecutive days. A significant increase in oxidative stress biomarkers was detected in the heart tissue of BDL animals. Moreover, it was found that heart tissue mitochondrial indices of functionality were deteriorated in the BDL group. Tau treatment significantly decreased oxidative stress and improved mitochondrial function in the heart tissue of cirrhotic animals. These data provide clues for the involvement of mitochondrial impairment and oxidative stress in the pathogenesis of heart injury in BDL rats. On the other hand, Tau supplementation could serve as an effective ancillary treatment against BDL-associated heart injury. Mitochondrial regulating and antioxidative properties of Tau might play a fundamental role in its mechanism of protective effects in the heart tissue of BDL animals.

Green Synthesis and Characterization of Copper Nanoparticles and Their Effects on Liver Function and Hematological Parameters in Mice

Objectives

The present investigation is based on the green synthesis of copper nanoparticles (CuNPs) from aqueous extract of Capparis spinosa L. fruit. Their effects on liver function and hematological parameters in mice were evaluated.

Materials and Methods

The green synthesis of CuNPs by means of C. spinosa extract was achieved. Ultraviolet-visible spectroscopy, fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy were used to identify the synthesized nanoparticles. BALB/c mice were orally administrated CuNPs at doses of 1000, 2000, and 5000 μg/kg for 2 weeks. Later, the effects of CuNPs on liver function in the treated mice were evaluated by measuring the serum levels of enzymes such as alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and bilirubin as well as hematological parameters including hemoglobin, hematocrit, white blood cell, red blood cell, and platelet counts.

Results

A maximum peak at wavelength 414 nm confirmed the biosynthesis of CuNPs. FTIR spectrum analysis revealed that the factor groups shaped a coating extract on the surface of the nanoparticles. SEM images demonstrated a particle size between 17 and 41 nm. Although some liver enzymes and hematological parameters increased with increasing dose of extract, there was no significant difference (p>0.05) between oral administrations of CuNPs at doses of 1000, 2000, and 5000 μg/kg and the control group.

Conclusion

The findings revealed that CuNPs biosynthesized from aqueous extract of C. spinosa fruit have no toxic effects on the liver functions and hematological parameters of mice. However, more studies are needed for evaluation of the hepatoprotective effects of CuNPs.

Mitochondrial dysfunction: A hidden trigger of autism?

Autism is a heterogeneous neurodevelopmental and neuropsychiatric disorder with no precise etiology. Deficits in cognitive functions uncover at early stages and are known to have an environmental and genetic basis. Since autism is multifaceted and also linked with other comorbidities associated with various organs, there is a possibility that there may be a fundamental cellular process responsible for this. These reasons place mitochondria at the point of interest as it is involved in multiple cellular processes predominantly involving metabolism. Mitochondria encoded genes were taken into consideration lately because it is inherited maternally, has its own genome and also functions the time of embryo development. Various researches have linked mitochondrial mishaps like oxidative stress, ROS production and mt-DNA copy number variations to autism. Despite dramatic advances in autism research worldwide, the studies focusing on mitochondrial dysfunction in autism is rather minimal, especially in India. India, owing to its rich diversity, may be able to contribute significantly to autism research. It is vital to urge more studies in this domain as it may help to completely understand the basics of the condition apart from a genetic standpoint. This review focuses on the worldwide and Indian scenario of autism research; mitochondrial abnormalities in autism and possible therapeutic approaches to combat it.

Antioxidant Functionalized Nanoparticles: A Combat against Oxidative Stress

Numerous abiotic stresses trigger the overproduction of reactive oxygen species (ROS) that are highly toxic and reactive. These ROS are known to cause damage to carbohydrates, DNA, lipids and proteins, and build the oxidative stress and results in the induction of various diseases. To resolve this issue, antioxidants molecules have gained significant attention to scavenge these free radicals and ROS. However, poor absorption ability, difficulty in crossing the cell membranes and degradation of these antioxidants during delivery are the few challenges associated with both natural and synthetic antioxidants that limit their bioavailability. Moreover, the use of nanoparticles as an antioxidant is overlooked, and is limited to a few nanomaterials. To address these issues, antioxidant functionalized nanoparticles derived from various biological origin have emerged as an important alternative, because of properties like biocompatibility, high stability and targeted delivery. Algae, bacteria, fungi, lichens and plants are known as the producers of diverse secondary metabolites and phenolic compounds with extraordinary antioxidant properties. Hence, these compounds could be used in amalgamation with biogenic derived nanoparticles (NPs) for better antioxidant potential. This review intends to increase our knowledge about the antioxidant functionalized nanoparticles and the mechanism by which antioxidants empower nanoparticles to combat oxidative stress.

The therapeutic potential of losartan in lung metastasis of colorectal cancer

Colorectal cancer (CRC) is a common cancer with a high incidence rate. Components of the renin-angiotensin system (RAS) have been reported to be dysregulated in several malignancies including CRC. Here, we have explored the potential anti-metastatic effects of a RAS inhibitor, losartan, in an experimental model of lung metastasis in CRC. A murine model of lung metastasis of CRC was used, which involved the intravenous injection of CT26 cells via a tail vein. Four experimental groups comprised: an untreated group; a group that received 5-FU which was administered intraperitoneally; a losartan group and a combination group that received 5-FU plus losartan. We evaluated the anti-inflammatory effects of losartan by histopathological method, and the measurement of oxidative or antioxidant markers including malondialdehyde (MDA) and total thiol (T-SH) tissue levels, superoxide dismutase (SOD) and catalase activity. We found that losartan inhibited lung metastasis of CRC and there was a reduction of the IL-6 expression level in the tissue sample. It was also associated with reduced levels of the anti-angiogenic factor vascular endothelial growth factor (VEGF). Furthermore, we found that losartan induced oxidative stress as assessed by an elevation of MDA level, reduction of T-SH, SOD and catalase activities in lung tissue. Our findings demonstrated that losartan ameliorates angiogenesis, inflammation and the induction of oxidative stress via angiotensin II type I receptor (AT1R). This may shine some lights on targeting the RAS pathway as a potential therapeutic approach in the treatment of metastatic CRC patients.

Aflatoxins as a risk factor for liver cirrhosis: a systematic review and meta-analysis

Background

Liver cirrhosis is characterized by fibrosis and nodule formation in the liver, due to a chronic injury, and subsequent alteration of the normal architecture of the liver. Even though there is a huge effort to elucidate the possible etiologic factors of liver cirrhosis, a significant number of cases are cryptogenic, especially in Sub Saharan Africa, where there is a high burden of aflatoxin exposure. Aflatoxins are known to cause hepatocellular carcinoma, which share similar etiologic factors with liver cirrhosis. This study aimed to assess the association between aflatoxin exposure and the risk of liver cirrhosis.

Methods

Relevant studies were identified through systematic searches conducted in Ovid MEDLINE, PubMed and Google Scholar. Also, by searching the references of retrieved articles. The abstracts and full text were screened for eligibility and the risk of bias was assessed for each study using Joanna Briggs Institute (JBI) critical appraisal checklist for observational studies. The extracted data from included studies using Microsoft Excel were exported to Stata software version 15.0 for analyses. The overall pooled estimation of outcomes was calculated using a random-effects model of DerSimonian–Laird method at a 95% confidence level. The heterogeneity of studies was determined using I2 statistics. The presence of publication bias between studies was evaluated using the Begg’s and Egger’s tests and funnel plot. The protocol of this systematic review and meta-analysis was registered in the Prospero database with reference number ID: CRD42019148481.

Results

A total of 5 studies published between the years 2005 and 2018 that met the pre-defined inclusion and exclusion criteria were included. The meta-analysis showed that a significant increase in the risk of liver cirrhosis is associated with aflatoxin exposure (unadjusted pooled odds ratio (OR) = 3.35, 95% CI: 2.74–4.10, p = 0.000; I² = 88.3%, p = 0.000; adjusted OR = 2.5, 95% CI: 1.84–3.39, p = 0.000; I² = 0%, p = 0.429).

Conclusions

The present meta-analysis suggests that aflatoxin exposure is associated with a higher risk of liver cirrhosis.

Dietary nanoencapsulated quercetin homeostated transcription of redox-status orchestrating genes in zebrafish (Danio rerio) exposed to silver nanoparticles

The present study assessed the protective effect of chitosan-nanoencapsulated quercetin (Qu-ChiNPs) against oxidative stress caused by silver nanoparticles (AgNPs). To this end, the transcription of prime genes regulating hepatic Keap1-Nrf2 pathway as well as downstream antioxidant enzymes were monitored prior to and after oxidative stress by AgNPs. Zebrafish (Danio rerio; n = 225) was assigned into five experimental groups based on feeding with diets supplemented with different additives as follows: negative and positive control groups, without additive; ChiNPs, 400 mg nanochitosan per kg diet; Quercetin, 400 mg free quercetin per kg diet; and Qu-ChiNPs, 400 mg Qu-ChiNPs per kg diet. At the end of the feeding trial (40 days), the experimental groups, except the negative control, were exposed to sublethal concentration of AgNPs (0.15 mg L^-1) for 96h. Before exposure to AgNPs, free quercetin-treated diet significantly upregulated Keap1, Nrf2, Cat, SOD, GPx, and GST genes in the liver tissue when compared with the control diet, whereas Qu-Chi.NPs downregulated their transcription to the lowest levels. After exposure to AgNPs, all genes exhibited different responses in the AgNPs-exposed groups. The highest transcription of Nrf2, Cat, SOD, GPx, and GST was observed in the positive group, with being upregulated about 8, 10, 8, 8, and 7 times, respectively, when compared to the respective ones in the negative control. However, Keap1 showed a reverse response with being transcripted 12 times lower. The quercetin treatments, especially Qu-Chi.NPs, significantly reduced the transcription of Nrf2, Cat, SOD, GPx, and GST genes, yet enhanced Keap1 expression. Qu-Chi.NPs reduced the expression of Nrf2, SOD, Cat, GPx, and GST about 11, 10, 15, 10, and 10 times, respectively, yet increased that of Keap1 about 12 times. Taken together, nanoencapsulation can improve the antioxidant efficacy of quercetin against AgNPs toxicity and might reduce involvement of the cellular antioxidant system through tuning redox status. More broadly, it would be interesting to assess the effects of Qu-Chi.NPs against other metallic and organic oxidative stressors or pollutants.

N-acetyl cysteine treatment preserves mitochondrial indices of functionality in the brain of hyperammonemic mice

AIM OF THE STUDY

Acute or chronic live failure could result in hyperammonemia and hepatic encephalopathy (HE). HE is a clinical complication characterized by severe cognitive dysfunction and coma. The ammonium ion (NH4 +) is the most suspected toxic molecule involved in the pathogenesis of HE. NH4 + is a neurotoxic agent. Different mechanisms, including oxidative/nitrosative stress, inflammatory response, excitotoxicity, and mitochondrial impairment, are proposed for NH4 +-induced neurotoxicity. N-acetyl cysteine (NAC) is a well-known thiol-reductant and antioxidant agent. Several investigations also mentioned the positive effects of NAC on mitochondrial function. In the current study, the effect of NAC treatment on brain mitochondrial indices and energy status was investigated in an animal model of HE.

MATERIAL AND METHODS

Acetaminophen (APAP)-induced acute liver failure was induced by a single dose of the drug (800 mg/kg, i.p.) to C57BL/6J mice. Plasma and brain levels of NH4 + were measured. Then, brain mitochondria were isolated, and several indices, including mitochondrial depolarization, ATP level, lipid peroxidation, glutathione content, mitochondrial permeabilization, and dehydrogenase activity, were assessed.

RESULTS

A significant increase in plasma and brain NH4 + was evident in APAP-treated animals. Moreover, mitochondrial indices of functionality were impaired, and mitochondrial oxidative stress biomarkers were significantly increased in APAP-treated mice. It was found that NAC treatment (100, 200, and 400 mg/kg, i.p.) significantly mitigated mitochondrial impairment in the brain of APAP-treated animals.

CONCLUSIONS

These data suggest the effects of NAC on brain mitochondrial function and energy status as a pivotal mechanism involved in its neuroprotective properties during HE.

Bioactive compounds from Aspergillus niger extract enhance the antioxidant activity and prevent the genotoxicity in aflatoxin B1-treated rats

This study aimed to identify the bioactive compounds of the ethyl acetate extract of Aspergillus niger SH2-EGY using GC-MS and to evaluate their protective role against aflatoxin B₁ (AFB₁)-induced oxidative stress, genotoxicity and cytotoxicity in rats. Six groups of male Sprague-Dawley rats were treated orally for 4 weeks included the control group, AFB₁-treated group (80 μg/kg b.w); fungal extract (FE)-treated groups at low (140) or high dose (280) mg/kg b.w and the groups treated with AFB₁ plus FE at the two tested doses. The GC-MS analysis identified 26 compounds. The major compounds found were 1,2,3,4,6-Penta-trimethylsilyl Glucopyranose, Fmoc-L-3-(2-Naphthyl)-alanine, D-(-)-Fructopyranose, pentakis (trimethylsilyl) ether, bis (2-ethylhexyl) phthalate, trimethylsilyl ether-glucitol, and octadecanamide, N-(2- methylpropyl)-N-nitroso. The in vivo results showed that AFB₁ significantly increased serum ALT, AST, creatinine, uric acid, urea, cholesterol, triglycerides, LDL, carcinoembryonic antigen, alpha-fetoprotein, interleukin-6, Malondialdehyde, nitric oxide, Bax, caspase-3 and P53 mRNA expression, chromosomal aberrations and DNA fragmentation. It decreased serum TP, albumin, HDL, Bcl-2 mRNA expression, hepatic and renal TAC, SOD and GPx content and induced histological changes in the liver and kidney. FE prevented these disturbances in a dosage-dependent manner. It could be concluded that A. niger SH2-EGY extract is safe a promising agent for pharmaceutical and food industries.

Quercetin Loaded Monolaurate Sugar Esters-Based Niosomes: Sustained Release and Mutual Antioxidant-Hepatoprotective Interplay

Flavonoids possess different interesting biological properties, including antibacterial, antiviral, anti-inflammatory and antioxidant activities. However, unfortunately, these molecules present different bottlenecks, such as low aqueous solubility, photo and oxidative degradability, high first-pass effect, poor intestinal absorption and, hence, low systemic bioavailability. A variety of delivery systems have been developed to circumvent these drawbacks, and among them, in this work niosomes have been selected to encapsulate the hepatoprotective natural flavonoid quercetin. The aim of this study was to prepare nanosized quercetin-loaded niosomes, formulated with different monolaurate sugar esters (i.e., sorbitan C12; glucose C12; trehalose C12; sucrose C12) that act as non-ionic surfactants and with cholesterol as stabilizer (1:1 and 2:1 ratio). Niosomes were characterized under the physicochemical, thermal and morphological points of view. Moreover, after the analyses of the in vitro biocompatibility and the drug-release profile, the hepatoprotective activity of the selected niosomes was evaluated in vivo, using the carbon tetrachloride (CCl₄)-induced hepatotoxicity in rats. Furthermore, the levels of glutathione and glutathione peroxidase (GSH and GPX) were measured. Based on results, the best formulation selected was glucose laurate/cholesterol at molar ratio of 1:1, presenting spherical shape and a particle size (PS) of 161 ± 4.6 nm, with a drug encapsulation efficiency (EE%) as high as 83.6 ± 3.7% and sustained quercetin release. These niosomes showed higher hepatoprotective effect compared to free quercetin in vivo, measuring serum biomarker enzymes (i.e., alanine and aspartate transaminases (ALT and AST)) and serum biochemical parameters (i.e., alkaline phosphatase (ALP) and total proteins), while following the histopathological investigation. This study confirms the ability of quercetin loaded niosomes to reverse CCl₄ intoxication and to carry out an antioxidant effect.

Arctium lappa Root Extract Prevents Lead-Induced Liver Injury by Attenuating Oxidative Stress and Inflammation, and Activating Akt/GSK-3β Signaling

Arctium lappa L. (A. lappa) is a popular medicinal plant with promising hepatoprotective activity. This study investigated the protective effect of A. lappa root extract (ALRE) on lead (Pb) hepatotoxicity, pointing to its ability to modulate oxidative stress, inflammation, and protein kinase B/Akt/glycogen synthase kinase (GSK)-3β signaling. Rats received 50 mg/kg lead acetate (Pb(Ac)₂) and 200 mg/kg ALRE or vitamin C (Vit. C) for 7 days, and blood and liver samples were collected. Pb(Ac)₂ provoked hepatotoxicity manifested by elevated serum transaminases and lactate dehydrogenase, and decreased total protein. Histopathological alterations, including distorted lobular hepatic architecture, microsteatotic changes, congestion, and massive necrosis were observed in Pb(II)-induced rats. ALRE ameliorated liver function and prevented all histological alterations. Pb(II) increased hepatic lipid peroxidation (LPO), nitric oxide (NO), caspase-3, and DNA fragmentation, and serum C-reactive protein, tumor necrosis factor-α, and interleukin-1β. Cellular antioxidants, and Akt and GSK-3β phosphorylation levels were decreased in the liver of Pb(II)-induced rats. ALRE ameliorated LPO, NO, caspase-3, DNA fragmentation and inflammatory mediators, and boosted antioxidant defenses in Pb(II)-induced rats. In addition, ALRE activated Akt and inhibited GSK-3β in the liver of Pb(II)-induced rats. In conclusion, ALRE inhibits liver injury in Pb(II)-intoxicated rats by attenuating oxidative injury and inflammation, and activation of Akt/GSK-3β signaling pathway.

A systematic review on hepatoprotective activity of quercetin against various drugs and toxic agents: Evidence from preclinical studies

Quercetin is one of the most abundant flavonoids in human diet that has been reported to exhibit a wide range of pharmacological properties. The biochemical and molecular mechanisms involved in the hepatoprotective activity of quercetin were discussed in this review. Quercetin exhibited hepatoprotective activity against 2-butoxyethanol, acrylamide, acrylonitrile, aflatoxin B1, aroclor-1254, arsenic, sodium arsenite, azathioprine, cadmium chloride, carbon tetrachloride, chlorpyrifos, cyclosporine A, diazinon, dimethylnitrosamine, doxorubicin, epirubicin, ethanol, fenvalerate, isoniazide, rifampicin, lead acetate, lindane, D-galactosamine, methotrexate, methylmercury, nickel sulfate, paracetamol, perfluorooctanoic acid, polychlorinated biphenyls, pyrrolizidine alkaloid clivorine, rotenone, sodium fluoride, streptazotocin, tert-butyl hydroperoxide, thioacetamide, titanium dioxide, tumor necrosis factor-α, tripterygium glycoside, triptolide, ultraviolet A light, concavalin A, bisphenol, and ischemia-induced hepatotoxicity in various animal models due to its antioxidant, free radical-scavenging,anti-inflammatory, antiapoptotic, and cytochrome P450 2E1 (CYP2E1) inhibitory activities. In this review, we provide an overview of the possible mechanisms by which quercetin reduced the hepatotoxicity of different hepatotoxicants. This will help the toxicologists, pharmacologists, and chemists to develop new safer pharmaceutical products with quercetin and other hepatotoxicants.

Effect of curcumin on hippocampus dentate gyrus injury induced by nicotine in rats

Introduction: Nicotine is the most important alkaloid compound in tobacco and is a major risk factor in the development of functional disorder of several organ systems. Some plants produce Curcumin, which has antioxidant and neuroprotective properties. This study was designed to evaluate the therapeutic effects of curcumin against nicotine injury on the hippocampus CA1 region of rats. Methods: In this study, 48 male Wistar rats were randomly assigned to eight groups: Normal control (saline) group, Nicotine control group (0.5 mg/kg); Curcumin groups (10, 30, and 60 mg/kg) and Nicotine + Curcumin groups (10, 30, and 60 mg/kg). Treatments were administered intraperitoneally daily for 28 days. Golgi staining technique investigated the number of dendritic spines. Cresyl violet staining method was used to determine the number of neurons in hippocampal region CA1. Griess technique was assessed to determine serum nitrite oxide level. Also, the Ferric reducing/antioxidant power (FRAP) method was applied to determine the total antioxidant capacity. Results: Nicotine administration significantly increased nitrite oxide level and decreased total antioxidant capacity as well as the number of neuronal dendritic spines and neurons compared to the normal control group (P < 0.01). In all Curcumin and Nicotine + Curcumin groups, the number of neurons, neuronal dendritic spines, and total antioxidant capacity increased significantly compared to the nicotine control group, while nitrite oxide level decreased significantly compared to the nicotine control group (P < 0.01). Conclusion: Curcumin administration can improve hippocampal CA1 region injury induced by nicotine.

Carnosine Mitigates Manganese Mitotoxicity in an In Vitro Model of Isolated Brain Mitochondria

Purpose: Manganese (Mn) is a neurotoxic chemical which induces a wide range of complications in the brain tissue. Impaired locomotor activity and cognitive dysfunction are associated with high brain Mn content. At the cellular level, mitochondria are potential targets for Mn toxicity. Carnosine is a dipeptide abundantly found in human brain. Several pharmacological properties including mitochondrial protecting and antioxidative effects have been attributed to carnosine. The current study aimed to evaluate the effect of carnosine treatment on Mn-induced mitochondrial dysfunction in isolated brain mitochondria.

Methods: Mice brain mitochondria were isolated based on the differential centrifugation method and exposed to increasing concentrations of Mn (10 µM-10 mM). Carnosine (1 mM) was added as the protective agent. Mitochondrial indices including mitochondrial depolarization, reactive oxygen species (ROS) formation, mitochondrial dehydrogenases activity, ATP content, and mitochondrial swelling and permeabilization were assessed.

Results: Significant deterioration in mitochondrial indices were evident in Mn-exposed brain mitochondria. On the other hand, it was found that carnosine (1 mM) treatment efficiently prevented Mn-induced mitochondrial impairment.

Conclusion: These data propose mitochondrial protection as a fundamental mechanism for the effects of carnosine against Mn toxicity. Hence, this peptide might be applicable against Mn neurotoxicity with different etiologies (e.g., in cirrhotic patients).

Time-Course Effects of Acute Aflatoxin B1 Exposure on Hepatic Mitochondrial Lipids and Oxidative Stress in Rats

Aflatoxins are secondary metabolites of certain Aspergillus species, that contaminate staple foods, particularly in developing countries. Aflatoxin B1 (AFB1) is the most toxic and common of the major types of aflatoxins. AFB1 is hepatotoxic and has been implicated in increasing the risk of hepatocellular carcinoma (HCC). We have previously shown that subacute exposure to AFB1 for 7 days disrupts hepatic lipids; therefore, this study determined the time-course effects of acute aflatoxin exposure on hepatic mitochondrial lipids and oxidative stress. To achieve this, thirty male albino rats were randomly assigned to six groups. The groups received an oral dose of 1 mg/kg body weight AFB1 or vehicle only (controls) for one, four, or seven days, respectively. Twenty-four hours after the last dose, the animals were sacrificed and liver excised. Mitochondria and cytosolic fractions were obtained from the liver after which lipids (cholesterol, triacylglycerols) were determined in the mitochondria while biomarkers of oxidative stress (glutathione, glutathione transferase (GST), glutathione peroxidase (GPx), glutathione reductase, nitric oxide (NO), malonaldehyde (MDA), thioredoxin reductase (TR), and superoxide dismutase (SOD) were determined spectrophotometrically in the mitochondria and cytosolic fractions. The expression of genes (Nrf2, Acc, Nqo1, and HmgCoa) were determined using quantitative RT-PCR. Results showed that AFB1 significantly increased mitochondrial cholesterol at day seven (treatment vs. control, p = 0.016). It also increased the concentrations of NO and MDA at day one and day seven while the activity of GPx and concentration of GSH were increased at day seven (p = 0.030) and day one (p = 0.025) alone, respectively, compared to control. The activities of cytosolic GR (p = 0.014), TR (p = 0.046) and GST (p = 0.044) were increased at day seven. AFB1 significantly increased the expression of Nrf2 (p = 0.029) and decreased the expression of Acc (p = 0.005) at day one. This study revealed that AFB1 disrupts hepatic mitochondrial lipids and antioxidant capacity. These changes were dependent on the timing of exposure and did not follow a linear time-course trend. These alterations could be part of the hepatic mitochondria response mechanism to acute AFB1 toxicity.