Ameliorative efficacy of tetrahydrocurcumin against arsenic induced oxidative damage, dyslipidemia and hepatic mitochondrial toxicity in rats

Arsenic and metabolic diseases: New insights from mesenchymal stem cells

Arsenic is a common toxic metal contaminant in the environment. Humans are exposed to arsenic through drinking water, air, food, and medical treatment. Chronic exposure to arsenic is a well-documented risk factor of type 2 diabetes and a potential risk factor of osteoporosis and obesity. Mesenchymal stem cells (MSCs) are adult stem cells with multiple differentiation potential and immunomodulatory capacity. These cells have shown therapeutic potential in experimental studies of metabolic diseases by differentiating into parenchymal cells of damaged tissues, such as islet-like cells and osteoblasts, and resisting chronic inflammation. Meanwhile, when key functional genes were suppressed in MSCs, experimental animals showed metabolic disease-related changes, such as insulin resistance and obesity. Arsenic exposure inhibits the differentiation capacity of MSCs, leads to changes in the synthesis and secretion of immunomodulatory factors, and induces cellular senescence and apoptosis. Therefore, dysfunction and death of MSCs may be important pathogenesis of arsenic-related metabolic diseases. Future studies on the functional changes of MSCs in arsenic-related metabolic diseases and the role of MSCs in arsenic pathogenesis are worthwhile. In addition, the mechanism of arsenic-induced dysfunction in MSCs needs to be explored in depth.

Therapeutic Potential of Cannabidiol Cyclodextrin Complex in Polymeric Micelle and Tetrahydrocurcumin Cyclodextrin Complex Loaded in Hydrogel to Treat Lymphedema

Cannabidiol (CBD) and tetrahydrocurcumin (THC) have demonstrated anti-inflammatory activity as well as generating new lymph vessels. We present the formulations and evaluations of CBD and THC loaded in hydrogels for the treatment of lymphedema to promote angiogenesis of lymph vessels and an anti-inflammatory response. Six CBD-THC hydrogel formulations were prepared and evaluated. The hydrodynamic particle sizes were 302.0-545.1 nm and the zeta potentials were from -58.80 to -33.63 mV. The hydrogel pHs were 6.43-6.54. The hydrogel formulations were non-toxic for both CBD (<25 µg/mL) and THC (<12.5 µg/mL). It was observed that high-molecular-weight hyaluronic acid in hydrogel affected collagen production. Hydrogel formulations at 2 µg/mL of CBD and 1 µg/mL of THC induced human dermal lymphatic endothelial cell tube formation. CBD-THC hydrogel formulations showed a notable ability to induce angiogenesis, which suggested its potential effectiveness in promoting new lymphatic vessel formation. Moreover, CBD-THC hydrogels showed anti-inflammatory properties. Further research is needed to ensure these treatments effectively enhance lymphatic repair.

Hepatotoxicity induced by arsenic trioxide: clinical features, mechanisms, preventive and potential therapeutic strategies

Arsenic trioxide (ATO) has shown substantial efficacy in the treatment of patients with acute promyelocytic leukemia, and the utilization of ATO as a potential treatment for other tumors is currently being investigated; thus, its clinical application is becoming more widespread. However, the toxicity of ATO has prevented many patients from receiving this highly beneficial treatment. The clinical features, mechanisms, and preventive measures for ATO hepatotoxicity, as well as potential curative strategies, are discussed in this review. This review not only discusses existing drugs for the treatment of hepatotoxicity but also focuses on potential future therapeutic agents, providing forward-looking guidance for the clinical use of small molecule extracts, trace elements, antidiabetic drugs, and vitamins.

Exploring the role of curcumin in mitigating oxidative stress to alleviate lipid metabolism disorders

Lipid metabolism plays a crucial role in maintaining homeostasis and overall health, as lipids are essential molecules involved in bioenergetic processes. An increasing body of research indicates that disorders of lipid metabolism can contribute to the development and progression of various diseases, including hyperlipidemia, obesity, non-alcoholic fatty liver disease (NAFLD), diabetes mellitus, atherosclerosis, and cancer, potentially leading to poor prognoses. The activation of the oxidative stress pathway disrupts lipid metabolism and induces cellular stress, significantly contributing to metabolic disorders. A well-documented crosstalk and interconnection between these metabolic disorders exists. Consequently, researchers have sought to identify antioxidant-rich substances in readily accessible everyday foods for potential use as complementary therapies. Curcumin, known for its anti-inflammatory and antioxidant properties, has been shown to enhance cellular antioxidant activity, mitigate oxidative stress, and alleviate lipid metabolism disorders by reducing reactive oxygen species (ROS) accumulation. These effects include decreasing fat deposition, increasing fatty acid uptake, and improving insulin sensitivity. A review of the existing literature reveals numerous studies emphasizing the role of curcumin in the prevention and management of metabolic diseases. Curcumin influences metabolic disorders through multiple mechanisms of action, with the oxidative stress pathway playing a central role in various lipid metabolism disorders. Thus, we aimed to elucidate the role of curcumin in various metabolic disorders through a unified mechanism of action, offering new insights into the prevention and treatment of metabolic diseases. Firstly, this article provides a brief overview of the basic pathophysiological processes of oxidative stress and lipid metabolism, as well as the role of oxidative stress in the pathogenesis of lipid metabolism disorders. Notably, the article reviews the role of curcumin in mitigating oxidative stress and in preventing and treating diseases associated with lipid metabolism disorders, including hyperlipidemia, non-alcoholic fatty liver disease (NAFLD), atherosclerosis, obesity, and diabetes, thereby highlighting the therapeutic potential of curcumin in lipid metabolism-related diseases.

Long-term arsenic exposure decreases mice body weight and liver lipid droplets

Arsenic (As) is a widespread global pollutant, and there is significant controversy surrounding its complex relationship with obesity, primarily focused on short-term exposure. Recognizing the prolonged nature of dietary arsenic exposure, this study involved feeding mice with arsenic-contained food for 14 months. The results showed that mice exposed to arsenic developed a non-alcoholic fatty liver condition, characterized by a light-yellow hue on the liver surface and various pathological alterations in the liver cells, including enlarged nuclei, cellular necrosis, inflammatory infiltration, dysfunctional mitochondria, and endoplasmic reticulum disorganization. There were also disruptions in biochemistry indices, with a significant increase in total cholesterol (TC) level and a decrease in high-density lipoprotein (HDL) level. However, some contradictory observations occurred, such as a significant decrease in body weight, triglyceride (TG) level, and the numbers of lipid droplets. Several genes related to lipid metabolism were tested, and a model was used to explain these discrepancies. Besides, examinations of the colon revealed compromised intestinal barrier function and signs of inflammation. Fecal 16S rRNA sequencing and pseudo-targeted metabolomics revealed disruptions in internal homeostasis, such as modules, nodes, connections, and lipid-related KEGG pathways. Fecal targeted metabolomics analyses of short-chain fatty acids (SCFAs) and bile acids (BAs) demonstrated a significant upregulation in three primary bile acids (CA, CDCA, TCDCA), four secondary bile acids (TUDCA, DCA, LCA, GUDCA), and total SCFAs level. Oxidative stress and inflammation were also evident. Additionally, based on correlation analysis and mediation analysis, it was assumed that changes in the microbiota (e.g., Dubosiella) can impact the liver metabolites (e.g., TGs) through alterations in fecal metabolites (e.g., LPCs). These findings provide a theoretical reference for the long-term effect of arsenic exposure on liver lipid metabolism.

Ivermectin-induced toxicity in HepG2 cells and the protective effect of tetrahydrocurcumin and vitamin C

Ivermectin (IVM) is a semi-synthetic antiparasitic derived from abamectin, one of the natural avermectins. The liver promotes metabolism and excretion of IVM, representing a risk of toxicity to this organ. The use of antioxidants to alleviate damage caused by chemicals has been increasingly studied. Thus, the aim of this study was to evaluate the effects of IVM on HepG2 cells to elucidate the mechanisms related to its toxicity and the possible protection provided by tetrahydrocurcumin (THC) and vitamin C. HepG2 cells were treated with IVM (1-25 μM) for 24 and 48 h. IVM was cytotoxic to HepG2 cells, denoted by a dose-dependent decrease in cell proliferation and metabolic activity. In addition, IVM induced damage to the cell membrane at all tested concentrations and for both incubation times. IVM significantly decreased the mitochondrial membrane potential from concentrations of 5 μM (24 h) and 1 μM (48 h). Additionally, IVM showed a time- and dose-dependent decrease in cellular adenosine triphosphate levels. The levels of reduced glutathione were decreased in a time- and dose-dependent manner, while IVM stimulated the production of reactive oxygen and nitrogen species (RONS) at all tested doses, reaching rates above 50% following treatment at 7.5 μM (24 h) or 5 μM (48 h). Treatment with THC (50 μM) and vitamin C (50 μM) protected against IVM-induced cytotoxicity and RONS production. These results suggest that oxidative damage is involved in IVM-induced toxicity in HepG2 cells, and that THC and vitamin C can mitigate the toxic effects caused by the compound.

N-acetylcysteine attenuates sodium arsenite-induced oxidative stress and apoptosis in embryonic fibroblast cells

In recent years, the increase in environmental pollutants has been one of the most important factors threatening human and environmental health. Arsenic, a naturally occurring element found in soil, water, and air, easily enters the human body and leads to many metabolic disorders. In this study, we focused on the possible protective effects of N-acetylcysteine (NAC) against sodium arsenite (As)-induced toxic effects on embryonic fibroblast cells. The effects of As and NAC treatment on cells were evaluated, including cytotoxicity, oxidative stress, and apoptosis. Embryonic fibroblast cells were exposed to As (ranging from 0.01 μM to 10 μM) and NAC (at a concentration of 2 mM) for 24 h. The assessment of cytotoxicity markers, such as cell viability and lactate dehydrogenase (LDH), showed that As significantly reduced cell viability and increased LDH levels. Furthermore, we observed that As increased the amount of reactive oxygen species (ROS) in the cell, decreased the activity of antioxidant enzymes, and triggered apoptosis in cells. Additionally, our research revealed that the administration of NAC mitigates the detrimental effects of As. The results showed that As exerted hazardous effects on embryonic fibroblast cells through the induction of oxidative stress and apoptosis. In this context, our study provides evidence that NAC may have a protective effect against the toxicity of As in embryonic fibroblast cells.

The role of tetrahydrocurcumin in disease prevention and treatment

In recent decades, natural compounds derived from herbal medicine or dietary sources have played important roles in prevention and treatment of various diseases and have attracted more and more attention. Curcumin, extracted from the Curcumae Longae Rhizoma and widely used as food spice and coloring agent, has been proven to possess high pharmacological value. However, the pharmacological application of curcumin is limited due to its poor systemic bioavailability. As a major active metabolite of curcumin, tetrahydrocurcumin (THC) has higher bioavailability and stability than curcumin. Increasing evidence confirmed that THC had a wide range of biological activities and significant treatment effects on diseases. In this paper, we reviewed the research progress on the biological activities and therapeutic potential of THC on different diseases such as neurological disorders, metabolic syndromes, cancers, and inflammatory diseases. The extensive pharmacological effects of THC involve the modulation of various signaling transduction pathways including MAPK, JAK/STAT, NF-κB, Nrf2, PI3K/Akt/mTOR, AMPK, Wnt/β-catenin. In addition, the pharmacokinetics, drug combination and toxicology of THC were discussed, thus providing scientific basis for the safe application of THC and the development of its dietary supplements and drugs.

Promotion of transcription factor EB-dependent autophagic process by curcumin alleviates arsenic-caused lung oxidative stress and inflammation in mice

Arsenic is a human carcinogen widely distributed in the environment, and arsenic exposure from drinking water has received widespread attention as a global public health problem. Curcumin is a natural bioactive substance with high efficiency and low toxicity extracted from turmeric, which has a variety of biological properties such as antioxidation, anti-inflammation, anticancer, and immuno-modulatory activities. Curcumin is widely used in daily life as a food additive and dietary supplement. However, its protective effects in lung injuries by chronic arsenic exposure orally remain unexplored. In this study, curcumin treatment not only significantly accelerated arsenic elimination and improved lung tissue morphology, but also decreased arsenic-generated ROS by activating Nrf2 and its down-stream antioxidants. Further, curcumin alleviated inflammatory changes in mice exposed to arsenic for 6 and 12 weeks, as manifested by lung MPO levels, total protein and cellular levels in bronchoalveolar lavage fluid (BALF), serum IL-4 levels, and MAPK/NF-κB expression in lung tissue. Notably, our study also confirmed that curcumin could promote the expression and nuclear translocation of the transcription factor EB (TFEB), as well as activate TFEB-regulated autophagy in lung tissue of arsenic-treated mice, accompanied by inhibition of the AKT-mTOR signaling pathway. Overall, our study here suggests that natural bioactive compound curcumin could alleviate arsenic-induced pulmonary oxidative stress and inflammation in vivo, which is closely related to enhanced TFEB activity and induction of the autophagic process.

Association between blood arsenic concentration and dyslipidemia: Mediating effect of lipid peroxidation in the elderly

BACKGROUND

The earlier investigations have revealed heavy metals exposure is implicated in the pathogenesis of dyslipidemia. The goal was to evaluated the relationship of blood arsenic (As) concentration with dyslipidemia in the elderly through a cross-sectional study.

METHODS

The entire 360 elderly population were selected. Fasting blood specimens, demographic information, and clinical characteristics were obtained. The concentration of blood As was detected using ICP-MS. Serum 8-iso-PGF2α, a biomarker of lipid peroxidation, was measured by ELISA.

RESULTS

Pearson correlative analysis hinted there were strong relationships of blood As with liver function indices in the elderly. Besides, blood As was positively associated with total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL-C), and apolipoprotein A-I (ApoA I). Further multivariate linear and logistic regression suggested that the incidences of TC and LDL-C elevation were upregulated with the rising tertiles of blood As. Blood As was positively related with the prevalence of dyslipidemia (OR=3.609; 95%CI: 1.353, 6.961). Additionally, serum 8-iso-PGF2α was dramatically and positively linked to the levels of blood As and lipid profiles. Mediation analyses verified that 8-iso-PGF2α partially mediated the correlations between blood As with TC (36.63%) and LDL-C (34.03%).

CONCLUSION

Blood As concentration is positively related to lipid profiles in the elderly. Higher blood As concentration elevates the prevalence of dyslipidemia. Lipid peroxidation partially mediates the correlation of As exposure with dyslipidemia.

Dissecting the role of cadmium, lead, arsenic, and mercury in non-alcoholic fatty liver disease and non-alcoholic steatohepatitis

The objective of the present study was to review the existing epidemiological and laboratory findings supporting the role of toxic metal exposure in non-alcoholic fatty liver disease (NAFLD). The existing epidemiological studies demonstrate that cadmium (Cd), lead (Pb), arsenic (As), and mercury (Hg) exposure was associated both with an increased risk of NAFLD and altered biochemical markers of liver injury. Laboratory studies demonstrated that metal exposure induces hepatic lipid accumulation resulting from activation of lipogenesis and inhibition of fatty acid β-oxidation due to up-regulation of sterol regulatory element-binding protein 1 (SREBP-1), carbohydrate response element binding protein (ChREBP), peroxisome proliferator-activated receptor γ (PPARγ), and down-regulation of PPARα. Other metabolic pathways involved in this effect may include activation of reactive oxygen species (ROS)/extracellular signal-regulated kinase (ERK) and inhibition of AMP-activated protein kinase (AMPK) signaling. The mechanisms of hepatocyte damage during development of metal-induced hepatic steatosis were shown to involve oxidative stress, endoplasmic reticulum stress, pyroptosis, ferroptosis, and dysregulation of autophagy. Induction of inflammatory response contributing to progression of NAFLD to non-alcoholic steatohepatitis (NASH) upon toxic metal exposure was shown to be mediated by up-regulation of nuclear factor κB (NF-κB) and activation of NRLP3 inflammasome. Moreover, epigenetic effects of the metals, as well as their effect on gut microbiota and gut wall integrity were also shown to mediate their role in NAFLD development. Despite being demonstrated for Cd, Pb, and As, the contribution of these mechanisms into Hg-induced NAFLD is yet to be estimated. Therefore, further studies are required to clarify the intimate mechanisms underlying the relationship between heavy metal and metalloid exposure and NAFLD/NASH to reveal the potential targets for treatment and prevention of metal-induced NAFLD.

In Vitro, In Silico, and In Vivo Studies of Cardamine hirsuta Linn as a Potential Antidiabetic Agent in a Rat Model

Diabetes mellitus (T2DM) is a multifaceted metabolic disorder with no definite treatment. In silico characterization can help to explain the interaction between molecules and predict 3D structures. The aim of the present study was to evaluate the hypoglycemic activities of the hydro-methanolic extract of Cardamine hirsuta in a rat model. In vitro antioxidant and α-amylase inhibitory assays were evaluated in the present study. Phyto-constituents were quantified using RP-UHPLC-MS analysis. Molecular docking of compounds into the binding site of different molecular targets, i.e., tumor necrosis factor (TNF-α), glycogen synthase kinase 3 β (GSK-3β), and AKT, was carried out. Acute toxicity model, in vivo antidiabetic effect, and the influence on biochemical and oxidative stress parameters were also investigated. T2DM was induced in adult male rats by streptozotocin using a high-fat diet model. Three different doses (125, 250, and 500 mg/kg BW) were orally gavaged for 30 days. Mulberrofuran-M and quercetin3-(6″caffeoylsophoroside) have demonstrated remarkable binding affinity toward TNF-α and GSK-3β, respectively. 2,2-Diphenyl-1-picrylhydrazyl and α-amylase inhibition assay exhibited IC50 values of 75.96 and 73.66 μg/mL, respectively. In vivo findings exhibited that 500 mg/kg body weight (BW) dose of the extract significantly decreased the blood glucose level, improved biochemical parameters as well as oxidative stress by reduction of lipid peroxidation, and increased high-density lipoproteins. Moreover, activities of glutathione-s-transferase, reduced glutathione, superoxide dismutase were enhanced, and cellular architecture in the histopathological examination was restored in treatment groups. The present study affirmed the antidiabetic activities of mulberrofuran-M and quercetin3-(6″caffeoylsophoroside) present in the hydro-methanolic extract of C. hirsuta, possibly due to the reduction in oxidative stress and α-amylase inhibition.

Evaluation of the Possible Protective Role of Nobiletin against Arsenic-Induced Liver Damage in Male Albino Rats

Arsenic (As) is a toxic contaminant present in organic and inorganic forms in the environment. Nobiletin (NOB) is a polymethoxy flavone that has recently gained substantial consideration due to its curative impacts. The present experiment was conducted to assess the hepatoprotective efficiency of NOB on As-generated hepatotoxicity. Twenty-four adult rats were equally distributed into four groups and designated as control, As (50 mg/kg)-treated, As + NOB (50 mg/kg and 25 mg/kg, respectively), and NOB (25 mg/kg)-treated groups. After 30 days, experimental animals were decapitated, then blood and tissue samples were collected for further analysis. The group treated with As showed a significant decrease in the activity of antioxidant enzymes, including catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), glutathione (GSH), glutathione reductase (GSR), and total antioxidant status (TAS), and a substantial increase in the accumulation of As in liver tissues, levels of total oxidant status (TOS), hydrogen peroxide (H₂O₂), and lipid peroxidation (TBARS). Significant increases in alanine aminotransferase (ALT), alkaline phosphatase (ALP), and aspartate aminotransferase (AST) levels were observed in As-treated rats. Moreover, nuclear factor (NF)-κB, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, interleukin (IL)-6, and cyclo-oxygenase (COX)-2 activity, as well as the levels of pro-apoptotic markers (Bax, Caspase-3, and Caspase-9) were increased on exposure to As. In contrast, the anti-apoptotic marker (Bcl-2) level was significantly decreased. As administration showed a significant disturbance in hepatic tissue histology. However, cotreatment of NOB with As considerably increased the antioxidant enzyme activity, with a noteworthy reduction in the deposition of As in hepatic tissues, TBARS, and H₂O₂ levels. NOB-administrated rats showed considerable recovery in terms of inflammation, apoptosis, and histological damage. Hence, NOB can be considered a useful curative compound due to its medicinal properties against As-prompted hepatotoxicity.

Role of biotransformation in the diazinon-induced toxicity in HepG2 cells and antioxidant protection by tetrahydrocurcumin

Diazinon (DZN) is an insecticide extensively used to control pests in crops and animals. However, its indicriminated use may lead to liver damage in animals and humans. This study aimed to evaluate the toxicity of DZN (25-150 µM) on human hepatoblastoma (HepG2) cells after 24 and 48 h of exposure and the role of its biotransformation on the toxicological potential. We also tested the protective effect of tetrahydrocurcumin (THC), an antioxidant agent, in the DZN-induced citotoxicity. DZN caused cytotoxicity in the HepG2 cells, inhibiting cell proliferation and reducing cell viability in a dose- and time-dependent manner. The pre-incubation of HepG2 cells with chemical inducers of cytochrome P450 monooxygenase 3-methylcholanthrene and phenobarbital resulted in a further decrease of cell viability associated with DZN exposure. In addition, the metabolite diazoxon was more toxic than DZN. Our results also revealed that THC alleviated DZN-induced cytotoxicity and reactive oxygen and nitrogen species (RONS) generation in HepG2 cells. In conclusion, our data provide novel insights into the involvement of biotransformation in the mechanisms of DZN-induced cytotoxicity and suggest that amelioration of RONS accumulation might be involved in the protective effect of THC on DZN-induced liver injury.

Tamarix articulata Induced Prevention of Hepatotoxicity Effects of In Vivo Carbon Tetrachloride by Modulating Pro-Inflammatory Serum and Antioxidant Enzymes to Reverse the Liver Fibrosis

This study evaluates the hepatoprotective activity of a Tamarix articulata extract against carbon tetrachloride-mediated hepatotoxicity in Wistar rats. Our results demonstrated that the oral administration of Tamarix articulata extract (50 mg/kg b.w.) significantly restored the serum levels of liver enzymes and antioxidant parameters (superoxide dismutase, catalase, glutathione reductase, and thiobarbituric reactive substances). Histopathology analysis revealed that Tamarix articulata extract significantly reduced hepatic fibrosis by inhibiting the necrosis of hepatocytes. Furthermore, serum pro-inflammatory (tumor necrosis factor-alpha, tumor growth factor-beta, and interleukin-6) markers were significantly restored. However, the anti-inflammatory cytokine adiponectin levels increased to normal levels in the group treated with Tamarix articulata extract. Additionally, we observed diminished reactive oxygen species production and the depolarization of mitochondrial membrane potential in hepatocytes extracted from animal livers treated with Tamarix articulata extract. Our findings suggest that Tamarix articulata extract prevents liver fibrosis induced by carbon tetrachloride and decreases the necrotic population of hepatocytes. These events restored the antioxidant enzymatic activity, serum levels of liver enzymes, and pro-inflammatory markers to their normal levels.

Natural Dietary Compounds in the Treatment of Arsenic Toxicity

Chronic exposure to arsenic (As) compounds leads to its accumulation in the body, with skin lesions and cancer being the most typical outcomes. Treating As-induced diseases continues to be challenging as there is no specific, safe, and efficacious therapeutic management. Therapeutic and preventive measures available to combat As toxicity refer to chelation therapy, antioxidant therapy, and the intake of natural dietary compounds. Although chelation therapy is the most commonly used method for detoxifying As, it has several side effects resulting in various toxicities such as hepatotoxicity, neurotoxicity, and other adverse consequences. Drugs of plant origin and natural dietary compounds show efficient and progressive relief from As-mediated toxicity without any particular side effects. These natural compounds have also been found to aid the elimination of As from the body and, therefore, can be more effective than conventional therapeutic agents in ameliorating As toxicity. This review provides an overview of the recently updated knowledge on treating As poisoning through natural dietary compounds. This updated information may serve as a basis for defining novel prophylactic and therapeutic formulations.

Arsenate and arsenite differential toxicity in Tetrahymena thermophila

A comparative analysis of toxicities of both arsenic forms (arsenite and arsenate) in the model eukaryotic microorganism Tetrahymena thermophila (ciliate protozoa) has shown the presence of various detoxification mechanisms and cellular effects comparable to those of animal cells under arsenic stress. In the wild type strain SB1969 arsenate is almost 2.5 times more toxic than arsenite. According to the concentration addition model used in binary metallic mixtures their toxicities show an additive effect. Using fluorescent assays and flow cytometry, it has been detected that As(V) generates elevated levels of ROS/RNS compared to As(III). Both produce the same levels of superoxide anion, but As(V) also causes greater increases in hydrogen peroxide and peroxynitrite. The mitochondrial membrane potential is affected by both As(V) and As(III), and electron microscopy has also revealed that mitochondria are the main target of both arsenic ionic forms. Fusion/fission and swelling mitochondrial and mitophagy, together with macroautophagy, vacuolization and mucocyst extruction are mainly associated to As(V) toxicity, while As(III) induces an extensive lipid metabolism dysfunction (adipotropic effect). Quantitative RT-PCR analysis of some genes encoding antioxidant proteins or enzymes has shown that glutathione and thioredoxin metabolisms are involved in the response to arsenic stress. Likewise, the function of metallothioneins seems to be crucial in arsenic detoxification processes, after using both metallothionein knockout and knockdown strains and cells overexpressing metallothionein genes from this ciliate. The analysis of the differential toxicity of As(III) and As(V) shown in this study provides cytological and molecular tools to be used as biomarkers for each of the two arsenic ionic forms.

Therapeutic effects of CoenzymeQ10, Biochanin A and Phloretin against arsenic and chromium induced oxidative stress in mouse (Mus musculus) brain

Arsenic and chromium are the most common environmental toxicants prevailing in nature. Hence, the present study endeavors to investigate the salutary effects of Coenzyme Q10 (CoQ10), Biochanin A (BCA), and Phloretin (PHL) on the combined neurotoxic impact of arsenic and chromium in the Swiss albino mice (Mus musculus). Sodium meta-arsenite (100 ppm) and potassium dichromate (75 ppm) were given orally in conjugation with CoQ10 (10 mg/kg), BCA & PHL (50 mg/kg each) in accordance with body weight per day for the 2 weeks experimental duration. Weight reduction was figured out in the exposed toxic group of arsenic and chromium in contrast with the comparison group (control), and with the selected anti-oxidants treatment, it rose significantly to the basal status (p < 0.05). The concentration of arsenic and chromium was reduced significantly (p < 0.001) amidst all the natural compounds co-medicated groups. Anti-oxidant indicators, viz. lipid peroxidation (LPO) and protein carbonyl content (PCC), were found elevated, with reduction observed in the levels of superoxide dismutase (SOD), reduced glutathione (GSH), glutathione s-transferase (GST), and total thiols (TT) in the arsenic and chromium, co-exposed mice. The alterations in redox homeostasis were well corroborated with the estimations of cholinesterase's enzymes (p < 0.05) along with DNA fragmentation assay and altered Nrf2 signaling. The administration of CoQ10, BCA, and PHL ameliorated the effects of arsenic and chromium induced oxidative stress in the exposed mice. Our research unfolds the remedial outcome of these natural compounds contrary to the combined arsenic and chromium associated-neurotoxicity in the experimental model.

Mitochondrial Dysfunction in Arsenic-Induced Hepatotoxicity: Pathogenic and Therapeutic Implications

Mitochondria are vital cellular organelles associated with energy production as well as cell signaling pathways. These organelles, responsible for metabolism, are highly abundant in hepatocytes that make them key players in hepatotoxicity. The literature suggests that mitochondria are targeted by various environmental pollutants. Arsenic, a toxic metalloid known as an environmental pollutant, readily contaminates drinking water and exerts toxic effects. It is toxic to various cellular organs; among them, the liver seems to be most affected. A growing body of evidence suggests that within cells, arsenic is highly toxic to mitochondria and reported to cause oxidative stress and alter an array of signaling pathways and functions. Hence, it is imperative to highlight the mechanisms associated with altered mitochondrial functions and integrity in arsenic-induced liver toxicity. This review provides the details of mechanistic aspects of mitochondrial dysfunction in arsenic-induced hepatotoxicity as well as various ameliorative measures undertaken concerning mitochondrial functions.

Arsenic and weight loss: At a crossroad between lipogenesis and lipolysis

Arsenic is found in soil, food, water and earth crust. Arsenic exposure is associated with chronic diseases such as cancer, cardiovascular disease as well as diabetes. One of complex effects of arsenic is on weight gain or loss. Involvement of arsenic in both weight loss and gain signaling pathways has previously been reported; however, too little attention has been paid to its weight reducing effect. Animal studies exhibited a role of arsenic in weight loss. In this regard, arsenic interference with endocrine system, leptin and adiponectin hormones as well as thermogenesis is more evidence. Apparently, arsenic-induced weight lossis generally meditated by its interaction with thermogenesis. In this review we have discussed the irregularities in metabolic pathways induced by arsenic that can lead to weight loss.

Curcumin functions as an anti-inflammatory and antioxidant agent on arsenic-induced hepatic and kidney injury by inhibiting MAPKs/NF-κB and activating Nrf2 pathways

Chronic arsenic exposure has been associated with various toxic effects, especially to the organs of liver and kidney. As a plant polyphenol, curcumin is the most vital bioactive ingredient of turmeric and has a wide range of pharmacological activities. In the present study, we investigated the potential roles of curcumin against arsenic-induced liver and kidney dysfunctions in mice. Curcumin treatment (200 mg/kg) not only decreased the deposition of arsenic in liver and kidney, but also relieved the hepatic and nephritic biochemical indexes (Glutamic oxaloacetic transaminase [AST], Alanine aminotransferase [ALT], albumin, and creatinine) altered by arsenic at doses of 10 and 25 mg/L via drinking water. What's more, curcumin exerted influences on the activities of myeloperoxidase and on the secretion of inflammatory cytokines in liver and kidney tissues. In addition, the levels of mitogen-activated protein kinases (MAPKs) and nuclear factor kappa B (NF-κB) phosphorylation were declining while NRF2-signaling targets were increasing in mice liver and kidney by curcumin administration. In conclusion, our results here suggest that curcumin could exert both anti-inflammatory and antioxidant functions on arsenic-induced hepatic and kidney injury by inhibiting MAPKs/NF-κB and activating Nrf2 pathways cooperatively.

Assessment of the hyperlipidemia risk for residents exposed to potential emitted metals in the vicinity of a petrochemical complex

Hyperlipidemia, which is associated with certain environmental factors, is a risk factor for cardiovascular disease. Heavy metals are important pollutants from industrial emissions. However, the relationship between the exposure to heavy metals and the occurrence of hyperlipidemia is limited. This study aimed to investigate the association between serum metal levels and the risk of hyperlipidemia in adults living near a petrochemical complex. Our study subjects were 959 residents aged above 35 years in 11 townships near the largest petrochemical complex in central Taiwan. The serum levels of chromium, arsenic, and mercury in the study subjects were measured. The basic characteristics of the study subjects were collected via a questionnaire survey, and the levels of blood lipid biomarkers were analyzed by health examination. The definition of hyperlipidemia was defined in the provided guidelines. Adjusted generalized linear and logistic regression models were applied to evaluate the associations between petrochemical-related metal exposure and hyperlipidemia. The study subjects had chromium, arsenic, and mercury serum levels of 3.24±3.45, 3.45±4.66, and 1.24±1.08 (μg/L), respectively, and close proximity of the study subjects to the petrochemical complex was significantly associated with increased serum metal levels. The results showed that the total cholesterol levels were significantly associated with the increased serum chromium, arsenic, and mercury levels. And, the LDL-C levels were significantly associated with the increased serum mercury levels. In addition, the increased serum arsenic and mercury levels of the study subjects were significantly associated with higher odds ratios for abnormal total cholesterol levels and the risk of hyperlipidemia. Residing in close proximity to a petrochemical complex and high arsenic and mercury exposure were associated with elevated blood lipid levels and an increased risk of hyperlipidemia among the residential population in the vicinity of the petrochemical industry.

Therapeutic effects of biochanin A, phloretin, and epigallocatechin-3-gallate in reducing oxidative stress in arsenic-intoxicated mice

One of the most common toxicant prevailing in our environment is the arsenic. The present study is an attempt to investigate the effects of some of the common flavonoids, such as biochanin A (BCA), phloretin, and epigallocatechin-3-gallate (EGCG), on arsenic toxicity in the Swiss albino mice. For this purpose, mice were orally treated with sodium meta-arsenite (20 mg/kg bw/day), along with co-administration of BCA (50 mg/kg bw/day), phloretin (50 mg/kg bw/day), and EGCG (40 mg/kg bw/day) for the 2-week duration. All the mice were euthanized at the end of the treatment period, and the observations were made in the following parameters. Arsenic reduced the sperm motility as compared with the control (p < 0.05) and was restored back to the normal status with the flavonoids treatment significantly (p < 0.05). The arsenic concentrations in the kidney and liver tissues were found significantly reduced with all the flavonoids co-treatment (p < 0.001). There was a reduction in the levels of superoxide dismutase (SOD), reduced glutathione (GSH), and glutathione S-transferase (GST) antioxidant markers, with the increased lipid peroxidation (LPO), protein carbonyl content (PCC), and catalase (CAT) levels in the arsenic-intoxicated mice performed in the different tissues. The biochemical homeostasis alterations were well correlated with the estimations of cholinesterase enzyme levels in the brain tissues (p < 0.05) along with DNA damage analysis (Comet) carried out in the blood cells (p < 0.05). These above results are well corroborated with the histopathological findings performed in the brain tissue, along with the increased upregulation seen in the Nrf2 signalling, with all the flavonoid co-treatment carried in the kidney tissue. The administration of BCA, phloretin, and EGCG, in a major way, reversed the alterations in the abovementioned parameters in the arsenic-intoxicated mice. Our findings revealed the beneficial effects of the flavonoids against the arsenic-induced toxicity, due to their ability to enhance the intracellular antioxidant response system by modulating the Nrf2 signaling pathway.

Protective efficacy of thymoquinone or ebselen separately against arsenic-induced hepatotoxicity in rat

Arsenic (As) exposure is associated with adverse health outcomes to the living organisms. In the present study, the hepato-protective ability of thymoquinone (TQ), the active principle of Nigella sativa seed, or ebselen (Eb), an organoselenium compound, against As intoxication in female rats was investigated. For this purpose, animals were allocated randomly into control, As (20 mg/kg), TQ (10 mg/kg), Eb (5 mg/kg), As+TQ, and As+Eb groups that were orally administered for 28 consecutive days. Arsenic exposure resulted in hepatic oxidative damage which was evidenced by marked decreases in antioxidant parameters (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione (GSH)) concomitant with high malondialdehyde (MDA) level. Furthermore, As toxicity induced significant elevations in liver accumulation of As, serum hepatic indices (aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), and total bilirubin (TB)), and apoptotic marker (B cell lymphoma 2(Bcl2), Bcl-2-associated X protein (Bax), and caspase 3) levels. Additionally, notable increments in hepatic fibrotic markers (epidermal growth factor (EFG) and transforming growth factor beta 1 (TGF-β1)) associated with high nitric oxide, interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), and myeloperoxidase (MPO) levels were noticed following As intoxication. Biochemical findings were well-supported by hepatic histopathological screening. The co-treatment of As-exposed rats with TQ or Eb considerably improved liver function and antioxidant status together with lessened hepatic As content, inflammation, apoptosis, and fibrosis. The overall outcomes demonstrated that TQ or Eb ameliorates As-induced liver injury through their favorable antioxidant, anti-inflammatory, anti-apoptotic, and fibrolytic properties.

Effects of arsenic exposure on lipid metabolism: a systematic review and meta-analysis

Lipid metabolism dysfunction is a risk factor for cardiovascular diseases. Reportedly, arsenic exposure could affect lipid metabolism, but this finding remains controversial. Herein, we updated and reevaluated evidence regarding the relationship between arsenic exposure and lipid metabolism. Electronic and manual searches were performed to determine the effect of arsenic exposure on lipid metabolism from inception up to 30 November 2019. Overall, five studies were included in our meta-analysis. Two reviewers independently extracted information. Standardized mean difference (SMD) and 95% confidence intervals (CI) were used to analyze the combined effects of four indicators related to lipid metabolism (total cholesterol [TC], triglyceride [TG], high-density lipoprotein [HDL], low-density lipoprotein [LDL]). Afterwards, subgroup and sensitivity analyses were performed to explore the source of heterogeneity. Publication bias was tested using funnel plots and Begg's test. In this study, we observed that arsenic exposure can affect lipid metabolism by reducing serum HDL levels and increasing serum LDL levels. Following subgroup analysis, the arsenic concentration appeared to affect lipid metabolism. Funnel plot and Begg's test suggested no asymmetry. In conclusion, we recommend that potential influencing factors, including age, exposure time, and multiple concentration gradients, should be considered to further explore the relationship between arsenic exposure and lipid metabolism.

Counteracting arsenic toxicity: Curcumin to the rescue?

Arsenicosis leads to various irreversible damages in several organs and is considered to be a carcinogen. The effects of chronic arsenic poisoning are a result of an imbalance between pro- and antioxidant homeostasis, oxidative stress, as well as DNA and protein damage. Curcumin, the polyphenolic pigment extracted from the rhizome of Curcuma longa, is well-known for its pleiotropic medicinal effects. Curcumin has been shown to have ameliorative effects in arsenic-induced genotoxicity, nephrotoxicity, hepatotoxicity, angiogenesis, skin diseases, reproductive toxicity, neurotoxicity, and immunotoxicity. This review aims to summarize the scientific evidence on arsenic toxicity in various organs and the ameliorative effects of curcumin on the arsenic toxicity.

An appraisal on molecular and biochemical signalling cascades during arsenic-induced hepatotoxicity

Arsenic is a ubiquitous metalloid compound commonly found in the environment, and it is usually found in combination with sulphur and metals. Arsenic is considered as a therapeutic as well as poisoning agent since ancient times. It causes toxic effects on different organs, mainly the liver. In this review, we focused on the molecular mechanism of arsenic-induced hepatotoxicity. Here we envisaged the bridge between arsenic and hepatotoxicity with particular focus on the level of hepatic enzymes such as ALT, AST, and ALP. Here, we attempted to elucidate the role of arsenic in redox imbalance on increased oxidative stress (elevated level of ROS, MDA and NO) and decreased antioxidant levels such as reduced GSH, catalase, and SOD. Oxidative stress induces mitochondrial dysfunction via apoptosis (AKT-PKB, MAPK, PI3/AKT, PKCδ-JNK, AKT/ERK, p53 pathways), fibrosis (TGF-β/Smad pathway), and necrosis and inflammation (TNF-α, NF-ĸB, IL-1, and IL-6). Along with that, arsenic activates caspases and Bax, decreases Bcl2 through mitochondrial dysfunction, and induces apoptosis regulatory mechanism. We believe the alteration of all these pathways leads to arsenic-induced hepatotoxicity.

The Cancer Chemopreventive and Therapeutic Potential of Tetrahydrocurcumin

In recent decades, cancer has been one of the leading causes of death worldwide. Despite advances in understanding the molecular basis of tumorigenesis, diagnosis, and clinical therapies, the discovery and development of effective drugs is an active and vital field in cancer research. Tetrahydrocurcumin is a major curcuminoid metabolite of curcumin, naturally occurring in turmeric. The interest in tetrahydrocurcumin research is increasing because it is superior to curcumin in its solubility in water, chemical stability, bioavailability, and anti-oxidative activity. Many in vitro and in vivo studies have revealed that tetrahydrocurcumin exerts anti-cancer effects through various mechanisms, including modulation of oxidative stress, xenobiotic detoxification, inflammation, proliferation, metastasis, programmed cell death, and immunity. Despite the pharmacological similarities between tetrahydrocurcumin and curcumin, the structure of tetrahydrocurcumin determines its distinct and specific molecular mechanism, thus making it a potential candidate for the prevention and treatment of cancers. However, the utility of tetrahydrocurcumin is yet to be evaluated as only limited pharmacokinetic and oral bioavailability studies have been performed. This review summarizes research on the anti-cancer properties of tetrahydrocurcumin and describes its mechanisms of action.

Exposure to arsenic during pregnancy and newborn mitochondrial DNA copy number: A birth cohort study in Wuhan, China

BACKGROUND

Arsenic (As) is a widely distributed environmental chemical with potentially different toxicities. However, little is known about the impact of maternal As exposure on newborn mitochondrial DNA copy number (mtDNAcn), which may lie on the pathway linking As exposure to adverse health impacts.

OBJECTIVES

We aimed to explore whether maternal As exposure was associated with newborn mtDNAcn.

METHODS

We conducted a birth cohort study of 762 mother-infant pairs in Wuhan, China, 2013-2015. Cord blood mtDNAcn was determined using qPCR. Maternal urinary As levels in each trimester were quantified by ICP-MS. Multiple informant models were used to examine the associations of repeated urinary As levels with cord blood mtDNAcn.

RESULTS

The median urinary As levels in the first, second, and third trimesters were 17.2 μg/L, 16.0 μg/L, and 17.0 μg/L, respectively. In the multivariate model, each doubling increase in the first-trimester urinary As level was associated with a 6.6% (95% CI: -12.4%, -0.5%) decrease in cord blood mtDNAcn. The highest versus lowest quintile of first-trimester urinary As level was associated with a 19.0% (95% CI: -32.9%, -2.2%) lower cord blood mtDNAcn. No significant associations of urinary As levels in the second and third trimesters with cord blood mtDNAcn were observed. The inverse relationship between first-trimester urinary As level and cord blood mtDNAcn was more pronounced among female infants.

CONCLUSIONS

First-trimester As exposure was related to decreased cord blood mtDNAcn. The potential health impacts of decreased mtDNAcn in early life need to be further clarified.

Epigallocatechin gallate attenuates arsenic induced genotoxicity via regulation of oxidative stress in balb/C mice

Arsenic is well known genotoxicant which causes the excessive generation of reactive oxygen species (ROS) and inhibition of antioxidant enzyme systems leading to cell damage through the activation of oxidative sensitive signaling pathways. Epigallocatechin gallate (EGCG), the main and active polyphenolic catechin present in green tea, has shown potent antioxidant, free radical scavenging and genoprotective activity in vivo. The present study attempted to investigate antioxidant and geno-protective efficacy of EGCG by regulating arsenic induced oxidative stress in mice. Animals received prophylactic and therapeutic treatments at two different doses (25 and 50 mg/kg b.wt.) of EGCG orally for 15 days and administered arsenic intraperitoneally at dose of 1.5 mg/kg b.wt (1/10th of LD₅₀) for 10 days. Arsenic intoxication revealed enhanced ROS production (114%) in lymphocytes; elevated levels of LPO (2-4 fold); reduced levels of hepato-renal antioxidants (approx. 45%) and augmented genomic fragmentation in hepato-renal tissues; increased chromosomal anomalies (78%) and micronucleation (21.93%) in bone marrow cells and comet tailing (25%) in lymphocytes of mice. Both pre and post treatments of EGCG decreased ROS production, restored lipid peroxidation (LPO) and reduced hepato-renal antioxidants levels, reduced the DNA fragmentation, number of chromosomal aberrations (CA), micronucleation (MN), and comet tailing but prophylactic treatment of 50 mg/kg b.wt was the most effective treatment in regulating arsenic induced oxidative stress. The effectiveness of this dose was furthermore validated by calculating the inhibitory index. Thus, results of present work empirically demonstrate free radical scavenging, anti-oxidative and genoprotective efficacy of EGCG against arsenic toxicity.

Recently highlighted nutraceuticals for preventive management of osteoarthritis

Osteoarthritis (OA) is a chronic degenerative disease of articular cartilage with limited treatment options. This reality encourages clinicians to suggest preventive measures to delay and contain the outbreak of the pathological conditions. Articular cartilage and synovium suffering from OA are characterised by an inflammatory state and by significant oxidative stress, responsible for pain, swelling and loss of mobility in the advanced stages. This review will focus on the ability of olive oil to exert positive effects on the entire joint to reduce pro-inflammatory cytokine release and increase lubricin synthesis, olive leaf extract, since it maintains lubrication by stimulating high molecular weight hyaluronan synthesis in synovial cells, curcumin, which delays the start of pathological cartilage breakdown, sanguinarine, which downregulates catabolic proteases, vitamin D for its capacity to influence the oxidative and pro-inflammatory environment, and carnosic acid as an inducer of heme oxygenase-1, which helps preserve cartilage degeneration. These molecules, considered as natural dietary supplements, appear like a cutting-edge answer to this tough health problem, playing a major role in controlling homeostatic balance loss and slowing down the pathology progression. Natural or food-derived molecules that are able to exert potential therapeutic effects are known as “nutraceutical”, resulting from the combination of the words “nutrition” and “pharmaceutical”. These compounds have gained popularity due to their easy availability, which represents a huge advantage for food and pharmaceutical industries. In addition, the chronic nature of OA implies the use of pharmacological compounds with proven long-term safety, especially because current treatments like nonsteroidal anti-inflammatory drugs and analgesics improve pain relief but have no effect on degenerative progression and can also cause serious side effects.

Arsenic-induced oxidative stress, cholinesterase activity in the brain of Swiss albino mice, and its amelioration by antioxidants Vitamin E and Coenzyme Q10

Arsenic toxicity becomes one of the major public health issues in several countries. Chronic and acute exposure to arsenic has been reported to be toxic to various systems of the human body and also observed in controlled experimental studies. The study was conducted to evaluate the neurotoxic effect of arsenic in Swiss albino mice and its amelioration by Vitamin E, Coenzyme Q10 and their combination. Swiss albino mice were treated with arsenic of 136 ppm for 15 days. The daily dose is 1/3 of LD 50 (acute) reported dose of arsenic. Thereafter, the animals were maintained either on drinking water or treated with Vitamin E (50 mg/kg bwt), Coenzyme Q10 (10 mg/kg bwt), and their combination by i.p.daily for 15 days. After the treatment, animals were sacrificed. The weight of the brain was marginally lower (ns), in arsenic-treated group as compared to control and antioxidant-protected groups. The LPO (lipid peroxidation) level was higher in arsenic-treated group, and this elevation was checked to some extent by the selected antioxidants which were statistically significant in combination of antioxidant-protected group. A significant reduction was found in GSH (reduced glutathione) level in the brain of arsenic-treated mice whereas GSH level was considerably higher in antioxidant-protected groups. Further, total thiol and total protein level were lower in arsenic-treated group. However, total thiol was significantly higher in antioxidant-protected groups. CAT (catalase) activity was significantly lower while SOD (superoxide dismutase) activity was marginally lowered in arsenic-treated group, and it was slightly higher in antioxidant-protected groups. Further, reduction in AChE (acetylcholinesterase) and BChE (butyrylcholinesterase) and motor coordination activity were also observed in arsenic-treated groups. Whereas, a higher AChE, BChE, and motor coordination activity was observed in antioxidant-protected group. These data indicate a positive role of selected antioxidant against the toxicity of arsenic in the brain of mice.

Acetyl-L-Carnitine Attenuates Arsenic-Induced Oxidative Stress and Hippocampal Mitochondrial Dysfunction

Augmentation of mitochondrial oxidative stress through activating a series of deadly events has implicated as the main culprit of arsenic toxicity and therapeutic approaches based on improving mitochondrial function hold a great promise for attenuating the arsenic-induced toxicity. Acetyl-L-carnitine (ALC) through balancing the coenzyme A (CoA)/acyl-CoA ratio plays an important role in mitochondrial metabolism and thereby can help protect hippocampal neurons from oxidative damage. In the present study, we aimed to explore the effect of arsenic interactions on the mitochondrial function in the hippocampus of rats. Rats were randomly divided into five groups of control (distilled water), sodium arsenite (NaAsO₂, 20 mg/kg), and co-treatment of NaAsO₂ with various doses of ALC in three groups (100, 200, 300 mg/kg) and were treated orally for 21 consecutive days. Our results point out that arsenic exposure caused oxidative stress in rats' hippocampus, which led to the reactive oxygen species (ROS) generation, mitochondrial swelling, the collapse of the mitochondrial membrane potential, and release of cytochrome c. It also altered Bcl-2/Bax expression ratio and increased caspase-3 and caspase-9 activities. Furthermore, arsenic exposure via activation of NF-κB and microglia increased inflammation. ALC could concentration-dependently counteract the arsenic-induced oxidative stress, modulate the antioxidant defense capacity, and improve mitochondrial functions. In addition, ALC decreased the expression of both death-associated proteins and of inflammatory markers. These findings indicate that ALC improved the arsenic-induced hippocampal mitochondrial dysfunction which underlines the importance of ALC in providing a possible therapeutic strategy for the prevention of arsenic-induced neurodegeneration.

Anxiolytic and anti-inflammatory role of thymoquinone in arsenic-induced hippocampal toxicity in Wistar rats

Arsenic (As) is a widely existing metalloid in the biosphere. Drinking water contamination by arsenic is a major route of human exposure, either by natural means or through industrial pollution. Numerous evidence form earlier reports suggest that arsenic exposure causes cerebral neurodegeneration which initiates behavioral disturbances concomitant to psychiatric disorders. Also, mood disorders in humans as well as in animals correlate with arsenic exposure; the present study is carried out to implore the neuroprotective potential of thymoquinone (TQ) in arsenic-stressed rats. TQ is an active component of Nigella sativa (Kalonji) seed oil. Arsenic exposure in the form of sodium arsenate (10 mg/kg/day; p.o) caused neurobehavioral deficits as evidenced by changes in locomotion and exploratory behavior in open-field and elevated plus maze tasks. Alongside this, arsenate also elevated hippocampal oxidative stress parameters like lipid peroxidation (TBARS) and protein carbonyl formation with a decrease in superoxide dismutase (SOD) and reduced glutathione (GSH) content. Genotoxicity assessment by Comet assay also showed prominent levels of DNA damage. Furthermore, arsenic also elevated hippocampal cytokine levels, TNF-α and INF-γ. However, TQ supplementation (2.5 and 5 mg/kg/day, p.o) preceded three days before arsenic administration, significantly attenuated arsenic-associated anxiogenic changes which majorly attributed to its antioxidant and anxiolytic potential. Also, TQ pre-treated rats expressed positive shifts in the hippocampal oxidative stress and cytokine levels with decreased DNA fragmentation. Thus, this study concludes that TQ might serve as a strong therapeutic agent for management of anxiety and depressive outcomes of arsenic intoxication.

Synthesis and Cytotoxic Activity of Novel Tetrahydrocurcumin Derivatives Bearing Pyrazole Moiety

Tetrahydrocurcumin (THC) is a major metabolite of curcumin and plays an important role in curcumin-induced biological effects. THC is a promising preventive and chemotherapeutic agent for cancer. A series of new pyrazole derivatives of THC have been synthesized as potent anticancer agents. Direct condensation of THC with various substituted hydrazines leads to new pyrazole derivatives of THC (1-18). The prepared compounds have been evaluated via in vitro MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay for their cell proliferation-inhibitory activity against human lung adenocarcinoma (A549), human cervical carcinoma (HeLa) and human breast carcinoma (MCF-7) cells. Most derivatives show significantly higher anticancer activity against all three tested cancer cell lines than the parent compound THC. Several compounds (7, 8, 12, 13 and 15) display promising anticancer activity against MCF-7 cell line with IC₅₀ values ranging from 5.8 to 9.3 µM. The most active compound (8) is substituted with 4-bromophenyl group at the pyrazole ring and inhibits the growth of all three tested cancer cell lines with an IC₅₀ values of (8.0 µM, A549), (9.8 µM, HeLa) and (5.8 µM, MCF-7). The obtained compounds can be a good starting point for the development of new lead molecules in the fight against cancer.

The involvement of Nrf2 in the protective effects of (-)-Epigallocatechin-3-gallate (EGCG) on NaAsO2-induced hepatotoxicity

Arsenic exposure produces hepatotoxicity. The common mechanism determining its toxicity is the generation of oxidative stress. Oxidative stress induced by arsenic leads to the activation of nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. (-)-Epigallocatechin-3-gallate (EGCG) possesses a potent antioxidant capacity and exhibits extensive pharmacological activities. This study aims to evaluate effects of EGCG on arsenic-induced hepatotoxicity and activation of Nrf2 pathway. Plasma activities of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and lactate dehydrogenase were measured; Histological analyses were conducted to observe morphological changes; Biochemical indexes such as oxidative stress (Catalase (CAT), malonyldialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), reactive oxygen species (ROS)), Nrf2 signaling related genes (Nrf2, Nqo1, and Ho-1) were assessed. The results showed that EGCG inhibited arsenic-induced hepatic pathological damage, liver ROS level and MDA level. Arsenic decreases the antioxidant enzymes SOD, GPX, and CAT activity and the decrease was inhibited by treatment of EGCG. Furthermore, EGCG attenuated the retention of arsenic in liver tissues and improved the expressions of Nrf2 signaling related genes (Nrf2, Nqo1, and Ho-1). These findings provide evidences that EGCG may be useful for reducing hepatotoxicity associated with oxidative stress by the activation of Nrf2 signaling pathway. Our findings suggest a possible mechanism of antioxidant EGCG in preventing hepatotoxicity, which implicate that EGCG may be a potential treatment for arsenicosis therapy.

All-Trans Retinoic Acid Ameliorates Arsenic-Induced Oxidative Stress and Apoptosis in the Rat Uterus by Modulating MAPK Signaling Proteins

Exposure to arsenic leads to inhibition of the anti-oxidant defense mechanism of the body. Reactive oxygen species generated in response to arsenic causes reproductive failures in exposed females and also acts as an inducer of apoptosis. As a prospective remedial agent, all-trans retinoic acid (ATRA) was assessed for reversing arsenic-induced oxidative stress and apoptosis. Rats exposed to arsenic for 28 days were allowed to recover naturally or were treated simultaneously with ATRA for 28 days or up to 56 days. Production of H₂ O₂ was detected using 2',7'-dichlorfluorescein diacetate (DCFCA) by flow cytometry. Catalase, superoxide dismutase, glutathione, ALT, and AST were estimated by biochemical assays and Western blot analyses. Detection of apoptosis was performed using annexin V-FITC/propidium iodide. Expressions of p53, p21, cleaved caspase 3, JNK/pJNK, and ERK/pERK levels were estimated using Western blot analysis. Elemental arsenic deposition in the rat uterus and liver was estimated by atomic absorption spectrophotometry. Our results confirmed that ATRA ameliorated sodium arsenite-induced ROS generation, restored redox balance, and prevented apoptosis. Concomitant recovery was observed to be more prominent for ATRA-treated rats as compared to the rats that were allowed to recover naturally for 56 days. Tissue arsenic deposition was significantly reduced in the uterus upon continuous ATRA treatment. The results revealed that ATRA reversed arsenic-induced free radical generation, activated the anti-oxidant defence system, and subsequently repressed p53-dependent apoptosis through inhibition of the MAPK signaling components. J. Cell. Biochem. 118: 3796-3809, 2017. © 2017 Wiley Periodicals, Inc.

Biological activities of curcuminoids, other biomolecules from turmeric and their derivatives - A review

In recent years, several drugs have been developed deriving from traditional products and current drug research is actively investigating the possible therapeutic roles of many Ayruvedic and Traditional Indian medicinal therapies. Among those being investigated is Turmeric. Its most important active ingredient is curcuminoids. Curcuminoids are phenolic compounds commonly used as a spice, pigment and additive also utilized as a therapeutic agent used in several foods. Comprehensive research over the last century has revealed several important functions of curcuminoids. Various preclinical cell culture and animals studies suggest that curcuminoids have extensive biological activity as an antioxidant, neuroprotective, antitumor, anti-inflammatory, anti-acidogenic, radioprotective and arthritis. Different clinical trials also suggest a potential therapeutic role for curcuminoids in numerous chronic diseases such as colon cancer, lung cancer, breast cancer, inflammatory bowel diseases. The aim of this review is to summarize the chemistry, analog, metal complex, formulations of curcuminoids and their biological activities.

Metabolism disrupting chemicals and metabolic disorders

The recent epidemics of metabolic diseases, obesity, type 2 diabetes(T2D), liver lipid disorders and metabolic syndrome have largely been attributed to genetic background and changes in diet, exercise and aging. However, there is now considerable evidence that other environmental factors may contribute to the rapid increase in the incidence of these metabolic diseases. This review will examine changes to the incidence of obesity, T2D and non-alcoholic fatty liver disease (NAFLD), the contribution of genetics to these disorders and describe the role of the endocrine system in these metabolic disorders. It will then specifically focus on the role of endocrine disrupting chemicals (EDCs) in the etiology of obesity, T2D and NAFLD while finally integrating the information on EDCs on multiple metabolic disorders that could lead to metabolic syndrome. We will specifically examine evidence linking EDC exposures during critical periods of development with metabolic diseases that manifest later in life and across generations.

Selenium Alleviates Oxidative Stress and Lung Damage Induced by Aluminum Chloride in Adult Rats: Biochemical and Histological Approach

Our study pertains to the potential ability of selenium, used as a nutritional supplement, to alleviate oxidative stress induced by aluminum chloride in the lung tissue. Rats have received during 21 days either aluminum chloride (AlCl₃) (400 ppm) via drinking water, AlCl₃ associated with Na₂SeO₃ (0.5 mg/kg of diet), or only Na₂SeO₃. Exposure of rats to AlCl₃ induced lung oxidative stress with an increase of malondialdehyde, hydrogen peroxide, and protein carbonyls levels. An alteration of lactate dehydrogenase activities and antioxidant redox status, enzymatic (catalase, superoxide dismutase, and glutathione peroxidase), and non-enzymatic (non-protein thiols, glutathione, metallothionein, and vitamin C) was also observed. These biochemical modifications were substantiated by histopathological data showing alveolar edema, a large number of hemosiderin-laden macrophages, and emphysema. Se supplementation attenuated the levels of oxidative stress by restoring antioxidant state and improved lung histological damage. Our results revealed that Se, a trace element with antioxidant properties, was effective in preventing lung damage.

Oxidative Damage Induced by Arsenic in Mice or Rats: A Systematic Review and Meta-Analysis

In this meta-analysis, studies reporting arsenic-induced oxidative damage in mouse models were systematically evaluated to provide a scientific understanding of oxidative stress mechanisms associated with arsenic poisoning. Fifty-eight relevant peer-reviewed publications were identified through exhaustive database searching. Oxidative stress indexes assessed included superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), glutathione peroxidase (GPx), glutathione-s-transferase (GST), glutathione reductase (GR), oxidized glutathione (GSSG), malondialdehyde (MDA), and reactive oxygen species (ROS). Our meta-analysis showed that arsenic exposure generally suppressed measured levels of the antioxidants, SOD, CAT, GSH, GPx, GST, and GR, but increased levels of the oxidants, GSSG, MDA, and ROS. Arsenic valence was important and GR and MDA levels increased to a significantly (P < 0.05) greater extent upon exposure to As³⁺ than to As⁵⁺. Other factors that contributed to a greater overall oxidative effect from arsenic exposure included intervention time, intervention method, dosage, age of animals, and the sample source from which the indexes were estimated. Our meta-analysis effectively summarized a wide range of studies and detected a positive relationship between arsenic exposure and oxidative damage. These data provide a scientific basis for the prevention and treatment of arsenic poisoning.