Hepatoprotective effects of zingerone on sodium arsenite-induced hepatotoxicity in rats: Modulating the levels of caspase-3/Bax/Bcl-2, NLRP3/NF-κB/TNF-α and ATF6/IRE1/PERK/GRP78 signaling pathways.

OBJECTIVE: Long-term exposure to arsenic has been linked to several illnesses, including hypertension, diabetes, hepatic and renal diseases and cardiovascular malfunction. The aim of the current investigation was to determine whether zingerone (ZN) could shield rats against the hepatotoxicity that sodium arsenite (SA) causes. METHODS: The following five groups of thirty-five male Sprague Dawley rats were created: I) Control; received normal saline, II) ZN; received ZN, III) SA; received SA, IV) SA + ZN 25; received 10 mg/kg body weight SA + 25 mg/kg body weight ZN, and V) SA + ZN 50; received 10 mg/kg body weight SA + 50 mg/kg body weight ZN. The experiment lasted 14 days, and the rats were sacrificed on the 15th day. While oxidative stress parameters were studied by spectrophotometric method, apoptosis, inflammation and endoplasmic reticulum stress parameters were measured by RT-PCR method. RESULTS: The SA disrupted the histological architecture and integrity of the liver and enhanced oxidative damage by lowering antioxidant enzyme activity, such as those of glutathione peroxidase (GPx), catalase (CAT), superoxide dismutase (SOD), glutathione (GSH) level and increasing malondialdehyde (MDA) level in the liver tissue. Additionally, SA increased the mRNA transcript levels of Bcl2 associated x (Bax), caspases (-3, -6, -9), apoptotic protease-activating factor 1 (Apaf-1), p53, tumor necrosis factor-α (TNF-α), nuclear factor kappa B (NF-κB), interleukin-1ß (IL-1ß), interleukin-6 (IL-6), c-Jun NH2-terminal kinase (JNK), mitogen-activated protein kinase 14 (MAPK14), MAPK15, receptor for advanced glycation endproducts (RAGE) and nod-like receptor family pyrin domain-containing 3 (NLRP3) in the liver tissue. Also produced endoplasmic reticulum stress by raising the mRNA transcript levels of activating transcription factor 6 (ATF-6), protein kinase RNA-like ER kinase (PERK), inositol-requiring enzyme 1 (IRE1), and glucose-regulated protein 78 (GRP-78). These factors together led to inflammation, apoptosis, and endoplasmic reticulum stress. On the other hand, liver tissue treated with ZN at doses of 25 and 50 mg/kg showed significant improvement in oxidative stress, inflammation, apoptosis and endoplasmic reticulum stress. CONCLUSIONS: Overall, the study's data suggest that administering ZN may be able to lessen the liver damage caused by SA toxicity.

Arsenite-Induced Drug-Drug Interactions in Rats.

Arsenite is an important heavy metal. Some Chinese traditional medicines contain significant amounts of arsenite. The aim of this study was to investigate subacute exposure of arsenite on activities of cytochrome P450 enzymes and pharmacokinetic behaviors of drugs in rats. Midazolam, tolbutamide, metoprolol, omeprazole, caffeine, and chlorzoxazone, the probe substrates for cytochrome P450 (CYP) s3A, 2C6, 2D, 2C11, 1A, and 2E, were selected as probe drugs for the pharmacokinetic study. Significant decreases in areas under the curves of probe substrates were observed in rats after consecutive 30-day exposure to As at 12 mg/kg. Microsomal incubation study showed that the subacute exposure to arsenite resulted in little change in effects on the activities of P450 enzymes examined. However, everted gut sac study demonstrated that such exposure induced significant decreases in intestinal absorption of these drugs by both passive diffusion and carrier-mediated transport. In addition, in vivo study showed that the arsenite exposure decreased the rate of peristaltic propulsion. The decreases in intestinal permeability of the probe drugs and peristaltic propulsion rate most likely resulted in the observed decreases in the internal exposure of the probe drugs. Exposure to arsenite may lead to the reduction of the efficiencies of pharmaceutical agents coadministered resulting from the observed drug-drug interactions. SIGNIFICANCE STATEMENT: Exposure to arsenite may lead to the reduction of the efficiencies of pharmaceutical agents coadministered resulting from the observed drug-drug interactions. The present study, we found that P450 enzyme probe drug exposure was reduced in arsenic-exposed animals (areas under the curve) and the intestinal absorption of the drug was reduced in the animals. Subacute arsenic exposure tends to cause damage to intestinal function, which leads to reduced drug absorption.

Tissue-, Region-, and Gene-Specific Induction of Microsomal Epoxide Hydrolase Expression and Activity in the Mouse Intestine by Arsenic in Drinking Water.

This study aimed to characterize the effects of arsenic exposure on the expression of microsomal epoxide hydrolase (mEH or EPHX1) and soluble epoxide hydrolase (sEH or EPHX2) in the liver and small intestine. C57BL/6 mice were exposed to sodium arsenite in drinking water at various doses for up to 28 days. Intestinal, but not hepatic, mEH mRNA and protein expression was induced by arsenic at 25 ppm, in both males and females, whereas hepatic mEH expression was induced by arsenic at 50 or 100 ppm. The induction of mEH was gene specific, as the arsenic exposure did not induce sEH expression in either tissue. Within the small intestine, mEH expression was induced only in the proximal, but not the distal segments. The induction of intestinal mEH was accompanied by increases in microsomal enzymatic activities toward a model mEH substrate, cis-stilbene oxide, and an epoxide-containing drug, oprozomib, in vitro, and by increases in the levels of PR-176, the main hydrolysis metabolite of oprozomib, in the proximal small intestine of oprozomib-treated mice. These findings suggest that intestinal mEH, playing a major role in converting xenobiotic epoxides to less reactive diols, but not sEH, preferring endogenous epoxides as substrates, is relevant to the adverse effects of arsenic exposure, and that further studies of the interactions between drinking water arsenic exposure and the disposition or possible adverse effects of epoxide-containing drugs and other xenobiotic compounds in the intestine are warranted. SIGNIFICANCE STATEMENT: Consumption of arsenic-contaminated water has been associated with increased risks of various adverse health effects, such as diabetes, in humans. The small intestinal epithelial cells are the main site of absorption of ingested arsenic, but they are not well characterized for arsenic exposure-related changes. This study identified gene expression changes in the small intestine that may be mechanistically linked to the adverse effects of arsenic exposure and possible interactions between arsenic ingestion and the pharmacokinetics of epoxide-containing drugs in vivo.

Response of petroleum-contaminated soil to chemical oxidation combined with biostimulation.

In this study, a microcosm experiment was conducted to investigate the effects of Na2S2O8 preoxidation combined with biostimulation on petroleum-contaminated soil remediation. The response of microbial community during this process was explored using BIOLOG ECO microplate carbon utilization method and 16 s rDNA high-throughput sequencing. The results showed that use of 10 mg/g Na2S2O8 removed 19.8 % of the petroleum hydrocarbons, reduced soil biotoxicity and did not affect soil microbial activity compared to other concentrations. Therefore, sodium persulfate of ca. 10 mg/g was used to oxidize petroleum in soil before the biostimulation experiment with organic and inorganic fertilizers. Our finding showed that the content of total petroleum hydrocarbons (TPHs) in soil was reduced by 43.3 % in inorganic fertilizer treatment after 60 days. The results of BIOLOG ECO microplate carbon utilization analysis and 16 S rDNA high-throughput sequencing further confirmed that biostimulation quickly restored the microbial activities in oxidant treated soil. The main marker bacteria in chemical oxidation combined with biostimulation remediation were Arthrobacter and Paenarthrobacter, and their relative abundances were both significantly negatively correlated with the content of petroleum hydrocarbons in soil.

Sodium arsenite induces hepatic stellate cells activation by m6A modification of TGF-ß1 during liver fibrosis.

The compound known as Sodium arsenite (NaAsO2), which is a prevalent type of inorganic arsenic found in the environment, has been strongly associated with liver fibrosis (LF), a key characteristic of nonalcoholic fatty liver disease (NAFLD), which has been demonstrated in our previous study. Our previous research has shown that exposure to NaAsO2 triggers the activation of hepatic stellate cells (HSCs), a crucial event in the development of LF. However, the molecular mechanism is still unknown. N6-methyladenosine (m6A) modification is the most crucial post-transcriptional modification in liver disease. Nevertheless, the precise function of m6A alteration in triggering HSCs and initiating LF caused by NaAsO2 remains unknown. Here, we found that NaAsO2 induced LF and HSCs activation through TGF-ß/Smad signaling, which could be reversed by TGF-ß1 knockdown. Furthermore, NaAsO2 treatment enhanced the m6A modification level both in vivo and in vitro. Significantly, NaAsO2 promoted the specific interaction of METTL14 and IGF2BP2 with TGF-ß1 and enhanced the TGF-ß1 mRNA stability. Notably, NaAsO2-induced TGF-ß/Smad pathway and HSC-t6 cells activation might be avoided by limiting METTL14/IGF2BP2-mediated m6A modification. Our findings showed that the NaAsO2-induced activation of HSCs and LF is made possible by the METTL14/IGF2BP2-mediated m6A methylation of TGF-ß1, which may open up new therapeutic options for LF brought on by environmental hazards.

Lysine specific demethylase 1 inhibits sodium arsenite activation of HSCs by regulating SESN2/AMPK/ULK1 signaling pathway activity.

Lysine specific demethylase 1 (LSD1) is a histone demethylase that specifically catalyzes the demethylation of histone H3K4 (H3K4me1/2) and regulates gene expression. In addition, it can mediate the process of autophagy through its demethylase activity. Sestrin2 (SESN2) is a stress-induced protein and a positive regulator of autophagy. In NaAsO2-induced mouse fibrotic livers and activated hepatic stellate cells (HSCs), LSD1 expression is decreased, SESN2 expression is increased, and autophagy levels are also increased. Overexpression of LSD1 and silencing of SESN2 decreased the level of autophagy and attenuated the activation of HSCs induced by NaAsO2. LSD1 promoted SESN2 gene transcription by increasing H3K4me1/2 in the SESN2 promoter region. 3-methyladenine (3-MA) and chloroquine were used to inhibit autophagy of HSCs, and the degree of activation was also alleviated. Taken together, LSD1 positively regulates SESN2 by increasing H3K4me1/2 enrichment in the SESN2 promoter region, which in turn increases the level of autophagy and promotes the activation of HSCs. Our results may provide new evidence for the importance of LSD1 in the process of autophagy and activation of HSCs induced by arsenic poisoning. Increasing the expression and activity of LSD1 is expected to be an effective way to reverse the autophagy and activation of HSCs induced by arsenic poisoning.

Sodium arsenite impairs sperm quality via downregulating the ZMYND15 and ZMYND10.

Zinc finger MYND-type containing 15 (ZMYND15) has been documented to play important roles in spermatogenesis, and mutants contribute to recessive azoospermia, severe oligozoospermia, non-obstructive azoospermia, teratozoospermia, even male infertility. ZMYND10 is involved in sperm motility. Whether environmental pollutants impair male fertility via regulating the expression of ZMYND15 and ZMYND10 has not been studied. Arsenic exposure results in poor sperm quality and male infertility. In order to investigate whether arsenic-induced male reproductive toxicity is related to the expression of ZMYND15, ZMYND10 and their target genes, we established a male rat model of sodium arsenite exposure-induced reproductive injury, measured sperm quality, serum hormone levels, mRNA and protein expressions of intratesticular ZMYND15 and ZMYND10 as well as their target genes. The results showed that, in addition to the increased mRNA expression of Tnp1, sodium arsenite exposure reduced sperm quality, serum hormone levels, and mRNA and protein expression of intratesticular ZMYND15 and ZMYND10 and their target genes in male rats compared with the control group (p < .05). Therefore, our study first showed that the environmental pollutant arsenic impairs sperm quality in male rats by reducing the expression of ZMYND10 and ZMYND15 and their regulatory genes, which provides a possible diagnostic marker for environmental pollutants-induced male infertility.

Betaine Protects Mice from Cardiotoxicity Triggered by Sodium Arsenite Through Antioxidative and Anti-inflammatory Pathways.

NaAsO2 is known as a harmful pollutant all over the world, and many chronic heart diseases can be attributed to its prolonged exposure in NaAsO2-contaminated water. Therefore, considering the anti-inflammatory and antioxidant effects of betaine (BET), in this study, our team investigated the cardioprotective effects of this phytochemical agent on sodium arsenite (NaAsO2)-induced cardiotoxicity. Forty male mice were randomly divided into 4 groups: (I) Control; (II) BET (500 mg/kg); (III) NaAsO2 (50 ppm); and (IV) NaAsO2 + BET. NaAsO2 was given to the animals for 8 weeks, but BET was given in the last two weeks. After decapitation, inflammatory factors and biochemical parameters were measured, and Western blot analyses were performed. BET decrease the activity level of alanine aspartate aminotransferase, creatine kinase MB, thiobarbituric acid reactive substances level, inflammatory factors (tumor necrosis factor-α) content, and nuclear factor kappa B expression. Furthermore, BET increased cardiac total thiol and activity levels of catalase, superoxide dismutase, and glutathione peroxidase and nuclear factor erythroid-2 expression. Hence, the administration of BET ameliorated the deleterious effects stemming from the imbalance of oxidative and antioxidant pathways and histopathological alterations observed in NaAsO2-intoxicated mice, thereby attenuating oxidative stress-induced damage and inflammation.

Ginkgo Biloba Extract Can Antagonize Subchronic Arsenite Exposure-Induced Hepatocyte Senescence by Inhibiting Oxidative Damage and Inflammation in Rats.

A growing body of evidence suggests that long-term arsenic exposure can induce liver injury. Our previous studies have demonstrated that liver injury occurs in arsenic-poisoning patients and arsenic-exposed rats. However, therapeutic targets are still unclear, and there is a lack of effective drugs. This study aimed to investigate the effects of sodium arsenite (arsenite) exposure on hepatocyte senescence and the intervention effect of ginkgo biloba extract in rats. In this study, 24 male Sprague-Dawley rats (weighing 180-200 g) were randomized into three groups. The control group received a normal diet, and the arsenic-exposed group was given 10 mg/L arsenite for 3 months by free drinking along with a normal diet. The ginkgo biloba extract treatment group was consecutively administered EGb761 (10 mg/kg, by gavage) for 1 month following 2 months of arsenite exposure. Our results showed that exposure to 10 mg/L arsenite induced narrowing of the hepatic sinus space, enlargement of hepatocytes, and increased multinucleated hepatocytes and inflammatory cell infiltration in rat liver tissue compared with the normal control group. Moreover, 10 mg/L arsenite also caused abnormal expression of inflammation-related indices (IL1-ß, IL-6, TNF-α), oxidative damage-related indices (SOD, MDA, GPx), and senescence-related proteins (p16, p-p53, E2F1). EGb761 could effectively reduce the pathological damage of liver tissue and antagonize the abnormal expression of liver tissue inflammation and oxidative damage-related indices as well as cellular senescence-related proteins caused by arsenite exposure. Notably, EGb761 reduced the accumulation of arsenic in rat liver tissues. These results suggested that EGb761 could effectively alleviate subchronic arsenic exposure-induced senescence of hepatocytes, which may be achieved partially through inhibiting inflammation and oxidative damage in rats. This study may provide a new therapeutic target for arsenic-induced liver injury.

mTORC1 - TFEB pathway was involved in sodium arsenite induced lysosomal alteration, oxidative stress and genetic damage in BEAS-2B cells.

The mechanistic target of rapamycin (RAPA) complex 1 (mTORC1) - transcription factor EB (TFEB) pathway plays a crucial role in response to nutritional status, energy and environmental stress for maintaining cellular homeostasis. But there is few reports on its role in the toxic effects of arsenic exposure and the related mechanisms. Here, we show that the exposure of bronchial epithelial cells (BEAS-2B) to sodium arsenite promoted the activation of mTORC1 (p-mTORC1) and the inactivation of TFEB (p-TFEB), the number and activity of lysosomes decreased, the content of reduced glutathione (GSH) and superoxide dismutase (SOD) decreased, the content of malondialdehyde (MDA) increased, the DNA and chromosome damage elevated. Further, when mTORC1 was inhibited with RAPA, p-mTORC1 and p-TFEB down-regulated, GSH and SOD increased, MDA decreased, the DNA and chromosome damage reduced significantly, as compared with the control group. Our data revealed for the first time that mTORC1 - TFEB pathway was involved in sodium arsenite induced lysosomal alteration, oxidative stress and genetic damage in BEAS-2B cells, and it may be a potential intervention target for the toxic effects of arsenic.

Melatonin protective role in mouse cauda epipidymal spermatozoa damage induced by sodium arsenite / Rol protector de la melatonina en el daño de espermatozoides de cauda epididimaria en ratón producido por arsenito de sodio

We evaluated the sperm parameters such as cauda epididymis weight, sperm count, sperm morphology and sperm DNA stability of adult CF-1 male mice treated daily (oral exposure) with the toxic sodium arsenite (As, 7.0 mg/kg/body weight); Melatonin (Me, 10.0 mg/kg/bw), Me (10.0 mg/kg/bw) plus As (7.0 mg/kg/bw) and Negative Control (NaCl 0.9 percent) to assess acute (8.3 days), chronic (33.2 days) and recovery of testicular damage (66.4 days). Arsenic decreases the number of sperm from chronic treatment (33.2 days) and this effect continued until 66.4 days of treatment. The toxic effect of As also altered the morphology of spermatozoa in all treatment periods when compared to the negative control group. However, Metalonin induced protective effects in periods of 33.2 and 66.4 days of treatment. Additionally, the stability of DNA was significantly affected by arsenic in all periods, but the chronic treatment (33.2 days) in the AsMe revealed increased stability compared to the group treated with arsenic only. Melatonin partially protects sperm toxicity caused by Arsenic, especially during periods of 33.2 and 66.4 days.

Se evaluaron los parámetros espermáticos como peso de la cola del epidídimo, conteo de espermatozoides, morfología de los espermatozoides y estabilidad del ADN de espermatozoides de ratones machos adultos CF-1 tratados diariamente (exposición oral) con el tóxico arsenito de sodio (As, 7,0 mg/kg/peso corporal), melatonina (Me, 10,0 mg/kg/pc, Me (10,0 mg/kg/pc) más As (7,0 mg/kg/pc) y el Control Negativo (NaCl 0,9 por ciento) en evaluación aguda (8,3 días), crónica (33,2 días) y recuperación del daño testicular (66.4 días). El arsénico reduce el número de espermatozoides en el tratamiento crónico (33,2 días) y este efecto continuó hasta 66,4 días. El efecto tóxico de As también altero la morfología de los espermatozoides en todos los períodos de tratamiento cuando se compara con el grupo control negativo. Sin embargo, metalonina indujo efectos protectores en períodos de 33,2 y 66,4 días de tratamiento. La estabilidad del ADN se vio afectada significativamente por el arsénico en todos los periodos, pero en el tratamiento crónico (33,2 días) con AsMe se observa un aumento de la estabilidad em comparación com el grupo tratado con arsénico. Sin embargo, la melatonina protege parcialmente a los espermatozoides del daño causado por arsénico, especialmente durante los períodos de 33,2 y 66,4 días.

In vitro induction of abnormal anaphases by contaminating atmospheric dust from the city of Mexicali, Baja California, Mexico

Mexicali dust (MD) is a mixture of particles of potassium aluminum silicates (98 percent) and sodium dioxide (2 percent) that induces pulmonary damage under experimental conditions, and is capable of inducing in vitro chromosomal alterations in exposed lymphocytes. It has been proposed as an atmospheric contaminant with pathogenic potential. among the chromosomal alterations observed, numeric alterations were predominant. The present study was designed to evaluate the capacity of MD to induce anaphasic changes in the Balb c 3T3 cell line. Chrysotile asbestos was used as a positive control. MD was found to induce abnormal anaphases, and the percentage of abnormalities increased as the dose increased (27.41 percent with 20 mg/mL, 29.60 percent with 40 mg/mL and 37.10 percent with 80 mg/mL). Multipolar anaphases constituted the most frequent altertion (69.1 - 78.8 percent), followed by lagging chromosomes (18.2 -29.5 percent) and anaphasic bridges (1.51 - 5.9 percent). The anaphasic alterations induced by MD showed differences in comparison to those observed with asbestos, especially for anaphasic bridges (10.4 percent vs. 1.51 percent, p<0.05). The capacity of MD to induce alterations resported in the process of chromosomal disjunction could explain the numeric aberrations reported previously by the authors of this paper. Therefore, these data support that MD could act as a clastogenic agent