Lophirones B and C prevent aflatoxin B1-induced oxidative stress and DNA fragmentation in rat hepatocytes

Effects of long-term Ailanthus altissima extract supplementation on fear, cognition and brain antioxidant levels

Introduction

Ailanthus altissima is an indigenous plant known for various remedial properties. The present study aimed to evaluate the neuroprotective potential of methanolic extract Ailanthus altissima (AA) bark as current scientific trend is searching plant for neurodegenerative diseases, worldwide.

Methodology

In in-vitro experiments, the AA was analyzed for phenols, flavonoids, antioxidative and cholinesterase inhibitory properties with subsequent detailed characterization for secondary metabolites. The in-vivo neurological effects were evaluated in rats through behavioral assessment for anxiety and memory after chronic administration (28 days) of 50-200 mg/kg of AA. At the end of behavior studies, isolated brains were biochemically tested to determine antioxidant enzyme activity.

Results

AA was found rich in phenols/flavonoids and active in radical scavenging with the presence of 13 secondary metabolites in UHPLC-MS analysis. The AA yielded anxiolytic effects dose-dependently in the open field, light/dark and elevated-plus maze tests as animals significantly (P < 0.05 vs control group) preferred open arena, illuminated zone and exposed arms of maze. Similarly, the animals treated with AA showed significant (P < 0.05 vs amnesic group) increase in spontaneous alternation, discrimination index in y-maze, novel object recognition tests. Further, AA.Cr treated rats showed noticeably shorter escape latencies in Morris water maze tests.In biochemical analysis, the dissected brains AA treated rats showed reduced levels of AChE and malondialdehyde with increased levels of first-line antioxidant enzymes i.e. glutathione peroxidase and superoxide dismutase. These observed biological effects might be attributed to phenols and flavonoids constituents owned by AA. -The in-silico studies showed thatconessine and lophirone J phytocompounds have good blood-brain barrier permeability and interaction with AChE.

Conclusion

The outcomes of this study validate that bark of Ailanthus altissima might work as a source of bioactive phytochemicals of neuroprotective potential.

Protective effect of copper II-albumin complex against aflatoxin B1- induced hepatocellular toxicity: The impact of Nrf2, PPAR-γ, and NF-kB in these protective effects

Copper II-Albumin complex (Cu-II-Albumin complex) is a novel therapeutic target that has been used as anti-inflammatory, antioxidant, and anti-gastrointestinal toxicity. In this study, 40 rats were divided into four groups, normal control (NC), aflatoxicosed group (AF) that received Aflatoxin B1 (AFB1) (50 μg/kg of the AFB1 daily for 3 weeks), AFB1-Cu-II-Albumin prophylactic group (AF/CUC-P) that subjected to intermittent treatment between AFB1 and Cu-II-Albumin complex (0.05 g/kg Cu-II-Albumin complex) day after day for 3 weeks and AFB1-Cu-II-albumin treatment group (AF/CUC-T) that received AFB1 for 3 weeks and Cu-II-albumin complex for another 3 weeks. The hepatocellular protective effect of the Cu-II-albumin complex was assessed by evaluating the liver functions markers, hepatic histopathology, reactive oxygen species (ROS) levels (Nitric Oxide (NO) and malondialdehyde (MDA)), apoptotic genes (caspase-3 and tumor necrosis factor receptor 1 [TNF-R1]) expressions, and serological and molecular biomarkers of hepatocellular carcinoma (histamine and Glucose-Regulated Protein 78 [GRP78], respectively). Our finding showed that Cu-II-Albumin Complex administration had restored liver function, oxidative stress levels, enhanced liver tissue recovery, and reduced the expression of the apoptotic genes of the aflatoxicosed rats. In conclusion, the current study results demonstrated the protective effect of Cu-II-albumin complex against AFB1-induced hepatocellular toxicity. PRACTICAL APPLICATIONS: The protective effect of Cu-II-Albumin Complex against AFB1-induced hepatocellular toxicity by assessing oxidative stress, liver biomarkers, inflammation, and histological changes of liver tissues. The protective mechanism of the Cu-II-albumin complex was also investigated. More clinical studies are required to evaluate the potential of using the Cu-II-albumin complex as a therapeutic agent against hepatocellular toxicity.

Exploration of plant products and phytochemicals against aflatoxin toxicity in broiler chicken production: Present status

Aflatoxins (AFs) are a class of mycotoxins produced by the toxigenic Aspergillus fungi and are common contaminants of foods and feeds. Aflatoxin B1 (AFB1), the most potent aflatoxin, is well characterized to reduce productive performance and mortality in broilers. This exclusive review summarizes the efficacy of various plant products and phytochemicals to counteract AFB1 toxicity in broilers. The biochemical and molecular mode of action of AFB1 to induce liver damage, genotoxicity, immunosuppression and the protective effect of plant products against such mechanisms and their toxic effects are discussed. The link between antioxidant, immunomodulatory and hepatoprotective functions of plant products; oxidative stress and AFB1 macromolecular adducts mediated AFB1 toxicity are covered. Efficacy of Satureja khuzistanica, Zataria multiflora Boiss, Thymus vulgaris, Sauropsus androgynus, Hemidesmus indicus, Leucas aspera, Moringa oleifera, Eclipta alba, Curcuma longa, Silybum marianum, Urtica dioica, and citrus fruit are summarized. The anti-aflatoxic effect of water-soluble substances of wheat, grape seed proanthocyanidin extract and phytochemicals like thymol, carvarol, piperine, transcinnamaldehyde, resveratrol, curcumin, and silymarin are also discussed. Specific plant products and phytochemicals are shown to be effective against AF toxicity in broilers and could represent an important tool to reduce health and economic losses associated with AFB1 exposure.

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.

Proteomics reveals the alleviation of zinc towards aflatoxin B1-induced cytotoxicity in human hepatocyes (HepG2 cells)

Aflatoxin B1 (AFB1) is a known carcinogen found in contaminated food and designated by the World Health Organization as a class I carcinogenic substance. AFB1 presents with carcinogenicity, teratogenicity, and mutagenicity, and the liver is the human organ most susceptible to AFB1. Zinc (Zn), which is one of the essential nutrient elements that could protect the cells from biological toxins, heavy metals, hydrogen peroxide, metal chelators and radiation, is assessed in this study for its potential to alleviate AFB1-induced cytotoxicity. Samples were divided into three groups, namely CK, AFB1, and AFB1+Zn. Protein expressions were analyzed by two-way electrophoresis combined with flight mass spectrometry, with 41 differentially expressed proteins identified in the results, mainly related to oxidative stress, cell apoptosis, DNA damage, and energy metabolism. Zn was found to regulate the expression of peroxidases (peroxiredoxin-1, peroxiredoxin-5, peroxiredoxin-6) to relieve AFB1-induced oxidative stress. Moreover, Zn could decrease the expression of pro-apoptotic genes (cleaved-caspase-3, caspase-9, and Bax) and increase the expression of anti-apoptotic genes (Bcl-2 and Bcl-xl) to alleviate the cell apoptosis induced by AFB1. In addition, AFB1 reduced intracellular ATP levels, whereas Zn supplementation boosted ATP levels and maintained homeostasis and a steady state of cellular energy metabolism by modulating AMPK-ACC phosphorylation levels, while many zinc finger proteins changed after AFB1 treatment. These results, therefore, indicate that Zn could alleviate AFB1-induced cytotoxicity by changing the expressions of zinc finger proteins in liver hepatocellular carcinoma (HepG2 cells).

Lophirones B and C induce oxidative cellular death pathway in Acinetobacter baumannii by inhibiting DNA gyrase

We evaluated the inactivation of DNA gyrase on the oxidative stress response and sensitivity of A. baumannii to lophirones B and C. The sensitivity of parental and the mutant strains of A. baumannii to lophirones B and C was determined using minimum inhibitory concentration (MIC) and time-kill sensitivity. Inactivation of sodB, katG, recA enhanced the sensitivity of A. baumannii to lophirones B and C. Furthermore, this inactivation increased the accumulation of superoxide anion radical and hydrogen peroxide in lophirones B and C-treated A. baumannii, which was reversed in the presence of thiourea. Inactivation of gyrA stalled lophirones B and C-mediated ROS accumulation in A. baumannii. In addition, lophirones B and C raised the Fe²⁺ contents of A. baumannii. Dipyridyl (Fe chelator) reversed the sensitivity of A. baumannii to lophirones B and C. Lophirones significantly lowered the NAD+/NADH ratio of A. baumannii. The results of this study revealed that the impact of DNA gyrase in lophirones B and C-mediated ROS accumulation, Fe²⁺ release and cell death.

DNA damage checkpoint response to aflatoxin B1

Although most countries regulate the aflatoxin levels in food by legislations, high amounts of aflatoxin B1 (AFB1)-DNA adducts can still be detected in normal and tumorous tissue obtained from cancer patients. AFB1 cannot directly interact with DNA unless it is biotransformed to AFB1-8, 9-epoxide via cytochrome p450 enzymes. This metabolite spontaneously and irreversibly attaches to guanine residues to generate highly mutagenic DNA adducts. AFB1-induced mutation of ATM kinase results in the deterioration of the cell cycle checkpoint activation at the G2/M checkpoint site. Genomic instability and increased cancer risk due to A-T mutation is the result of diminished repair of DNA double strand breaks. The major point mutation caused by AFB1 is G-to-T transversion that is related with the high frequency of p53 mutation. Majority of AFB1 associated hepatocellular cancer cases carry TP53 mutant DNA, which is an indicator of AFB1 exposure, as well as hepatocellular cancer risk.

Encapsulation of cinnamon essential oil in whey protein enhances the protective effect against single or combined sub-chronic toxicity of fumonisin B1 and/or aflatoxin B1 in rats

Fumonisin B₁ (FB₁) and aflatoxin B₁ (AFB₁) are fungal metabolites that frequently co-occur in foodstuffs and are responsible for mycotoxicosis and several primary cancers. Cinnamon essential oil (CEO) has a spacious range of benefit effects but also has some limitations owing to its strong taste or its interaction with some drugs. This study aimed to use the cinnamon oil emulsion droplets (COED) for the protection against oxidative stress, cytotoxicity, and reproductive toxicity in male Sprague-Dawley rats sub-chronically exposed to FB₁ and/or AFB₁. The composition of CEO was identified using GC-MS then was encapsulated using whey protein as wall material. Male rats were divided into eight groups and treated orally for 8 weeks as follows: control group, AFB₁-trreated group (80 μg/kg b.w), FB₁-treated group (100 mg/kg b.w), FB₁ plus AFB₁-treated group, and the groups treated with COED plus FB₁ and/or AFB₁. Blood and samples of the kidney, liver, and testis were collected for different analysis and histopathological examination. The GC-MS analysis revealed that cinnamaldehyde, α-copaene, trans-cinnamaldehyde, caryophyllene, and delta-cadinene were the main compounds in COE. The average size of COED was 235 ± 1.4 nm and the zeta potential was - 6.24 ± 0.56. Treatment with FB₁ and/or AFB₁ induced significant disturbances in the serum biochemical analysis, oxidative stress parameters, DNA fragmentation, gene expression, and testosterone and severe pathological changes in the tested organs. Moreover, treatment with both mycotoxins induced synergistic toxic effects. COED did not induce toxic effects and could normalize the majority of the tested parameters and improve the histological picture in rats treated with FB₁ and/or AFB₁. It could be concluded that COED induce potential protective effects against the single or combined exposure to FB₁ and AFB₁.