Grape skin extract mitigates tissue degeneration, genotoxicity, and oxidative status in multiple organs of rats exposed to cadmium

Arsenic intake-induced gastric toxicity is blocked by grape skin extract by modulating inflammation and oxidative stress in a mouse model

Arsenic (As) is known to induce toxic responses in many organs of human beings and animals. However, research concerning toxicity in the stomach is limited. In this study, arsenic-induced gastric toxicity was investigated in a mouse model, and grape skin extract (GSE) was confirmed to have protective effects against arsenic toxicity. Our experimental results showed that exposure to 10 mg/l arsenic via drinking water for 56 days caused oxidative damage and inflammatory responses. The H₂O₂ and malondialdehyde (MDA) contents were significantly increased, accompanied by significant decreases in total superoxide dismutase (T-SOD) activity and glutathione (GSH) content in the gastric tissue of arsenic-treated mice. Two inflammatory signalling pathways, i.e., TLR2/MyD88/NF-κB and IL-6/STAT-3, were activated, along with inflammatory cell infiltration and the elevated mRNA expression of pro-inflammatory cytokines (TNF-α, IL-1β and IFN-γ) and myeloperoxidase (MPO) in the gastric tissue of mice exposed to arsenic. Meanwhile, the mRNA levels of the ZO-1, ZO-2 and occludin genes, which encode the key components of tight junction (TJ) complexes, were downregulated. However, the application of GSE (300 mg/kg bw) significantly inhibited the arsenic-induced increases in H₂O₂ and MDA contents and the decreases in T-SOD activity and GSH content. The arsenic-mediated gene expression of pro-inflammatory cytokines (TNF-α, IL-1β and IFN-γ), MPO and IL-6/STAT3 and TLR2/MyD88/NF-κB pathways was found down-regulated. Moreover, the arsenic-induced inflammatory cell infiltration and inhibition of TJ genes transcription were markedly attenuated in the As+GSE (300 mg/kg bw) group. Based on the present findings, arsenic intake appears to cause gastric toxicity via oxidative stress and inflammation, and the application of GSE offers significant protection against arsenic toxicity in a mouse model by attenuating the oxidative stress and inflammatory response. Our results suggest that GSE by oral administration might function as a candidate therapeutic supplement to antagonize arsenic toxicity.

Plant Extracts and Isolated Compounds Reduce Parameters of Oxidative Stress Induced by Heavy Metals: An up-to-Date Review on Animal Studies

BACKGROUND

Heavy metals are elements that are naturally found in the earth. They are used in many modern-day applications in agriculture, medicine, and industry. Heavy metal poisoning occurs when the body's soft tissues absorb too much of a particular metal. The heavy metals of interest for this review paper were cadmium, arsenic, mercury, and lead since these are the most common metals that the human body can absorb in toxic amounts. Different plant species were investigated in recent years for their effect on oxidative stress parameters after intoxication with heavy metals.

OBJECTIVES

This review paper is focused on the current update to research on heavy metals induced oxidative stress in animal models and improvement of the oxidative stress parameters upon/co-/after treatment with different plant extracts and isolated compounds.

METHODS

The available literature was screened for the novel data regarding the influence of plant extracts and compounds on heavy metals induced oxidative stress. For that purposes Scopus database was used, looking for the publications in the last 5-10 years with the key terms: plant extracts, oxidative stress, in vivo, cadmium, lead, mercury and arcenic.

RESULTS

Various parameters of oxidative stress were investigated, and their improvement with plant extracts/ compounds was observed in the brain, lungs, kidneys, liver, uterus, testis, thymus, spleen, heart, skin and blood of experimental animals. Common parameters used to determine oxidative stress in animals were: superoxide dismutase; catalase; reduced glutathione; glutathione reductase; glutathione-S-transferase; glutathione peroxidase; lipid peroxidation; oxidized glutathione; malondialdehyde; xanthine oxidase; nonprotein-soluble thiol; thioredoxin reductase; total sulphydryl group; nitric oxide; γ-glutamyl cysteine synthetase.

CONCLUSION

The most investigated species for antioxidant effects upon intoxication with heavy metals seem to be Allium sp., Bacopa monniera, Camellia sinensis, Moringa oleifera, Vitis vinifera and Zingiber officinale. According to literature data, the most promising effect to alleviate symptoms of intoxication was achieved with proanthocyanidins obtained from Vitis vinifera.

Therapeutical properties of Mimosa caesalpiniifolia in rat liver intoxicated with cadmium

The aim of this study was to evaluate the therapeutic properties of Mimosa caesalpiniifolia in liver of rats exposed to cadmium under morphological, oxidative, inflammatory, and mutagenic parameters. A total of 40 Wistar rats (90 days, ~ 250 g) were distributed into eight groups (n = 5) as follows: (i) control; (ii) cadmium: cadmium chloride injection at 1.2 mg/kg; (iii) Mimosa extract: treatment with Mimosa extract at 250 mg/kg; (iv) Mimosa fraction: treatment with Mimosa acetate fraction at 62.5 mg/kg; (v) cadmium and Mimosa extract 62.5: submitted to cadmium chloride at 1.2 mg/kg injection and treatment with Mimosa extract at 62.5 mg/kg; (vi) cadmium and Mimosa extract 125: subjected to cadmium chloride at 1.2 mg/kg injection and treatment with Mimosa extract at 125 mg/kg; (vii) cadmium and Mimosa 250 extract: submitted to cadmium chloride 1.2 mg/kg injection and treatment with Mimosa extract at 250 mg/kg; (viii) cadmium treated with fraction of Mimosa acetate: submitted to cadmium chloride 1.2 mg/kg injection and treatment with acetate fraction of Mimosa extract at 62.5 mg/kg. In the animals intoxicated with cadmium and treated with fraction [62.5], increased expression of SOD-Mn reduced frequency of binucleated hepatocytes, karyolysis, and karyorrhexis, besides the antimutagenic and antioxidant action. The extract [62.5] was cytoprotective, antimutagenic, and reduced karyolysis. The extract [125] was cytoprotective, antioxidant, antifibrotic, anti-inflammatory, and reduced frequency of binucleated hepatocytes, while extract [250] was cytotoxic and mutagenic. In summary, the extract of Mimosa exerts some therapeutic properties in hepatic tissue after Cd intoxication, but only when it is administrated at intermediate doses. Probably, a high content of polyphenols in the EHM [250] and Fr-EtOAc groups exert pro-oxidant activities in the liver particularly when associated with Cd.

The Role of Natural Antioxidants Against Reactive Oxygen Species Produced by Cadmium Toxicity: A Review

Cadmium (Cd) is a significant ecotoxic heavy metal that adversely affects all biological processes of humans, animals and plants. Exposure to acute and chronic Cd damages many organs in humans and animals (e.g. lung, liver, brain, kidney, and testes). In humans, the Cd concentration at birth is zero, but because the biological half-life is long (about 30 years in humans), the concentration increases with age. The industrial developments of the last century have significantly increased the use of this metal. Especially in developing countries, this consumption is higher. Oxidative stress is the imbalance between antioxidants and oxidants. Cd increases reactive oxygen species (ROS) production and causes oxidative stress. Excess cellular levels of ROS cause damage to proteins, nucleic acids, lipids, membranes and organelles. This damage has been associated with various diseases. These include cancer, hypertension, ischemia/perfusion, cardiovascular diseases, chronic obstructive pulmonary disease, diabetes, insulin resistance, acute respiratory distress syndrome, idiopathic pulmonary fibrosis, asthma, skin diseases, chronic kidney disease, eye diseases, neurodegenerative diseases (amyotrophic lateral sclerosis, Parkinson's disease, Alzheimer's disease, and Huntington disease). Natural antioxidants are popular drugs that are used by the majority of people and have few side effects. Natural antioxidants play an important role in reducing free radicals caused by Cd toxicity. Our goal in this review is to establish the relationship between Cd and oxidative stress and to discuss the role of natural antioxidants in reducing Cd toxicity.

Genetic toxicity assessment using liver cell models: past, present, and future

Genotoxic compounds may be detoxified to non-genotoxic metabolites while many pro-carcinogens require metabolic activation to exert their genotoxicity in vivo. Standard genotoxicity assays were developed and utilized for risk assessment for over 40 years. Most of these assays are conducted in metabolically incompetent rodent or human cell lines. Deficient in normal metabolism and relying on exogenous metabolic activation systems, the current in vitro genotoxicity assays often have yielded high false positive rates, which trigger unnecessary and costly in vivo studies. Metabolically active cells such as hepatocytes have been recognized as a promising cell model in predicting genotoxicity of carcinogens in vivo. In recent years, significant advances in tissue culture and biological technologies provided new opportunities for using hepatocytes in genetic toxicology. This review encompasses published studies (both in vitro and in vivo) using hepatocytes for genotoxicity assessment. Findings from both standard and newly developed genotoxicity assays are summarized. Various liver cell models used for genotoxicity assessment are described, including the potential application of advanced liver cell models such as 3D spheroids, organoids, and engineered hepatocytes. An integrated strategy, that includes the use of human-based cells with enhanced biological relevance and throughput, and applying the quantitative analysis of data, may provide an approach for future genotoxicity risk assessment.

The protective effect of grape skin or purple carrot extracts against cadmium intoxication in kidney of rats

The aim of this study was to evaluate the protective effect of grape skin or purple carrot extracts against cadmium-induced intoxication in rats' kidneys. For this purpose, 30 male Wistar rats were distributed into six groups (n = 5), as follows: control group; cadmium group and groups treated with grape skin at 175 or 350 mg / L doses; or purple carrot extract at 400 mg / L or 800 mg / L doses, by drinking water. In the group exposed to cadmium, histopathological analysis revealed severe tissue injury as a result of coagulation necrosis, congested vessels and inflammatory infiltrate. Animals treated with grape skin or purple carrot extracts improved the histopathological changes induced by cadmium. 8-OHdG immunoexpression and catalase gene expression decreased in rats treated with purple carrot or grape skin extracts. Grape skin extract was able to increase SOD-CuZn gene expression as well. Toll-like signaling pathway (TLR2, PIKK and TRAF6) and cytochrome c expressions were not altered after the treatment with grape skin or purple carrot extracts. Taken together, we conclude that grape skin and purple carrot extracts had a protective effect on the rats' kidneys after cadmium intoxication, by means of tissue regenerating tissue regeneration and antioxidant properties, grape skin extract being more effective for this purpose.