Chronic arsenic exposure induces the time-dependent modulation of inflammation and immunosuppression in spleen

Advances in immunology of male reproductive toxicity induced by common environmental pollutants

Humans are exposed to an ever-increasing number of environmental toxicants, some of which have gradually been identified as major risk factors for male reproductive health, even associated with male infertility. Male infertility is usually due to the reproductive system damage, which may be influenced by the exposure to contaminants such as heavy metals, plasticizers, along with genetics and lifestyle. Testicular immune microenvironment (TIM) is important in maintaining normal physiological functions of the testis, whether disturbed TIM after exposure to environmental toxicants could induce reproductive toxicity remains to be explored. Therefore, the current review aims to contribute to the further understanding of exposure and male infertility by characterizing environmental exposures and the effect on TIM. We first summarized the male reproductive toxicity phenotypes induced by common environmental pollutants. Contaminants including heavy metals and plastic additives and fine particulate matter (PM2.5), have been repetitively associated with male infertility, whereas emerging contaminants such as perfluoroalkyl substances and micro(nano)plastics have also been found to disrupt TIM and lead to male reproductive toxicity. We further reviewed the importance of TIM and its homeostasis in maintaining the normal physiological functions of the testis. Most importantly, we discussed the advances in immunology of male reproductive toxicity induced by metals and metalloids, plastic additives, persistent organic pollutants (POPs), micro(nano)plastic and PM2.5 to suggest the importance of reproductive immunotoxicology in the future study of environmental toxicants, but also contribute to the development of effective prevention and treatment strategies for mitigating adverse effects of environmental pollutants on human health.

Short-term immunotoxicity induced by florpyrauxifen-benzyl herbicide exposure in the spleen of male albino mice

Florpyrauxifen-benzyl (FPB) is a new arylpicolinate systemic herbicide that has been used to control or suppress the majority of herbicide-resistant biotype weeds in rice. To our knowledge, the impact of FPB on the immune system remains undetected thus far. Hence, this work aimed to address the toxic effects of FPB and the possible related mechanisms on the spleen of exposed mice. Initially, an acute toxicological test was performed to ascertain the median lethal dose (LD50) of FPB for 24 h which was found to be 371.54 mg/kg b.wt. For mechanistic evaluation of FPB toxicity, three sublethal doses (1/20th, 1/10th, and 1/5th LD50) were orally administered to mice for 21 consecutive days. Changes in spleen relative weight, oxidative status, apoptotic and inflammatory markers, histopathological alterations were evaluated. Following the FPB exposure, significant (p < 0.05) decline in spleen index, apoptotic features, histolopathological changes were observed. Additionally, excessive oxidative stress in spleen tissues was monitored by downregulating antioxidant enzymes and upregulating the oxidant parameters. Furthermore, exposure to FPB resulted in notable activation of the NF-қB signaling pathway, accompanied by elevated levels of pro-inflammatory cytokines (namely, IL-1β and TNF-α) as well as CD3 and CD19 levels have decreased significantly in spleen tissues. Collectively, FPB exposure exhibited apoptosis, oxidative stress, immunosuppression, and inflammatory response in a dose-dependent manner, leading to spleen tissue damage and immunotoxicity. Further studies on FPB is recommended to outstand its hazards on ecosystems.

Co-administration of L-Ascorbic Acid and α-Tocopherol Alleviates Arsenic-Induced Immunotoxicities in the Thymus and Spleen by Dwindling Oxidative Stress-Induced Inflammation

Herein, we investigated whether L-ascorbic acid (L-AA) and α-tocopherol (α-T) co-administration has the potential to alleviate arsenic-induced immunotoxicities in the thymus, spleen, and circulating leukocytes. Forty-eight adult male Wistar rats were randomly divided into four groups before the treatment: group I (control); group II (sodium arsenite, 3 mg/kg/day/rat); group III (sodium arsenite + L-AA (200 mg/kg/day/rat) and α-T (400 mg/kg/day/rat)); group IV (L-AA and α-T). The result showed that sodium arsenite exposure (consecutive 30 days) caused weight reduction, structural alterations in the thymus and spleen, accompanied by a decrease in thymocyte and splenocyte count. Decreased superoxide dismutase and catalase activity, increased malondialdehyde and protein-carbonyl content, reduced Nrf2 and Bcl2 expression, and increased p-ERK, NF-kβ, Bax, and cleaved-caspase-3 expression were also observed in the thymus and spleen of arsenic-exposed rats. Enhanced plasma ACTH and corticosterone, ROS-induced apoptosis of lymphocytes were also observed. L-AA and α-T co-administration has the potential to abrogate the deleterious impact of arsenic on the thymus, spleen, and circulating lymphocytes. Whole transcriptome analysis of leukocytes revealed that arsenic treatment augmented the expression of Itga4, Itgam, and MMP9 genes, which might help in transient migration of the leukocytes through the endothelial cell layer. Co-administration with L-AA and α-T maintained Itga4, Itgam, and MMP9 gene expression within leukocytes at a lower level.

Gene expression analyses reveal potential mechanism of inorganic arsenic-induced apoptosis in zebrafish

Our previous study showed that sodium arsenite (200 mg/L) affected the nervous system and induced motor neuron development via the Sonic hedgehog pathway in zebrafish larvae. To gain more insight into the effects of arsenite on other signaling pathways, including apoptosis, we have performed quantitative polymerase chain reaction array-based gene expression analyses. The 96-well array plates contained primers for 84 genes representing 10 signaling pathways that regulate several biological functions, including apoptosis. We exposed eggs at 5 h postfertilization until the 72 h postfertilization larval stage to 200 mg/L sodium arsenite. In the Janus kinase/signal transducers and activators of transcription, nuclear factor κ-light-chain-enhancer of activated B cells, and Wingless/Int-1 signaling pathways, the expression of only one gene in each pathway was significantly altered. The expression of multiple genes was altered in the p53 and oxidative stress pathways. Sodium arsenite induced excessive apoptosis in the larvae. This compelled us to analyze specific genes in the p53 pathway, including cdkn1a, gadd45aa, and gadd45ba. Our data suggest that the p53 pathway is likely responsible for sodium arsenite-induced apoptosis. In addition, sodium arsenite significantly reduced global DNA methylation in the zebrafish larvae, which may indicate that epigenetic factors could be dysregulated after arsenic exposure. Together, these data elucidate potential mechanisms of arsenic toxicity that could improve understanding of arsenic's effects on human health.

Maternal Exposure to Arsenic and Its Impact on Maternal and Fetal Health: A Review

Arsenic exposure is a significant public health issue, with harmful effects caused by its use in commercial products such as car batteries, pesticides, and herbicides. Arsenic has three main compounds: inorganic, organic, and arsine gas. Inorganic arsenic compounds in water are highly toxic. The daily intake of arsenic from food and beverages is between 20 and 300 mcg/day. Arsenic is known for its carcinogenic properties and is classified as a human carcinogen by different institutions. Exposure can lead to oxidative stress, DNA damage, and epigenetic deregulation, which can cause endocrine disorders, altered signal transduction pathways, and cell proliferation. In addition, arsenic can easily cross the placenta, making it a critical concern for maternal and fetal health. Exposure can lead to complications such as gestational diabetes, anemia, low birth weight, miscarriage, and congenital anomalies. Female babies are particularly vulnerable to the negative impact of arsenic exposure, with a higher risk of low weight for gestational age and congenital cardiac anomalies. Therefore, it is crucial to monitor and regulate the levels of arsenic in drinking water and food sources to prevent these adverse health outcomes. Further research is necessary to fully understand the impact of arsenic exposure on human health, especially during pregnancy and infancy, by implementing preventative measures and monitoring the levels of arsenic in the environment.

Arsenic exposure and lung function decline in chronic obstructive pulmonary disease patients: The mediating influence of systematic inflammation and oxidative stress

Lung tissue is one of the target sites of arsenic (As). The goal of this investigation was to assess the associations of blood As concentration with pulmonary function indicators in patients with chronic obstructive pulmonary disease (COPD), as well as the roles of systemic inflammation and oxidative stress in this relationship. All 791 COPD patients were selected. Blood As concentration, and tumour necrosis factor-α (TNF-α) and 8-iso-prostaglandin-F2α (8-iso-PGF2α) were detected in the serum of COPD cases. Blood As was robustly related to pulmonary function parameters in an inverse dose-dependent manner. Multivariate linear regression analyses verified that a 1-unit increase of blood As was linked to declines of 0.263 L in FVC, 0.288 L in FEV1, 3.454 in FEV1/FVC%, and 0.538 in predicted FEV1%, respectively. The potential for pulmonary function decline gradually increased across the elevated tertiles of blood As. Nonsmokers were susceptible to As-induced pulmonary function reduction. Blood As was positively linked to the levels of TNF-α and 8-iso-PGF2α. Increased TNF-α and 8-iso-PGF2α partially mediated As-induced the reductions in FEV1 and FVC among COPD patients. As exposure is intensely linked to pulmonary function reduction. Systematic inflammation and oxidative stress partially mediate such associations in COPD patients.

Zingerone reduces sodium arsenite-induced nephrotoxicity by regulating oxidative stress, inflammation, apoptosis and histopathological changes

Arsenic is widely available in the environment and arsenic toxicity is a public health problem of serious concern worldwide. Zingerone is a promising phytochemical with various pharmacological effects. In this study, the potential protective effect of zingerone against sodium arsenite (NaAsO₂, SA) induced nephrotoxicity was investigated. Thirty-five male Sprague-Dawley rats were divided into five different groups as control, zingerone, SA, SA + zingerone 25, SA + zingerone 50. SA was administered alone at a dose of 10 mg/kg for 14 days or given 30 min before zingerone (25 mg/kg or 50 mg/kg) treatment. At the end of the experiment, the kidney tissues was examined biochemically, molecularly and microscopically. SA toxicity was associated with increased malondialdehyde level, whereas glutathione, superoxide dismutase, catalase, and glutathione peroxidase were decreased. Administration of SA caused inflammation in the kidney tissue by upregulation of NF-κB and IL-1β, TNF-α, IL-6, iNOS, COX-2, MAPK14, MAPK15, JNK. SA administration caused apoptosis in the kidney by upregulating caspase-3 and Bax levels and downregulating Bcl-2, and autophagy by activating beclin-1. Also, SA administration showed a suppressive effect on AKT2 and FOXO1 mRNA transcript levels. All these factors impair kidney function and increase creatinine and urea levels, resulting in pathological changes and a decrease in nephrin. Treatment with zingerone at doses of 25 and 50 mg/kg significantly reduced oxidative stress, inflammation, apoptosis and autophagy in kidney tissue. In addition, it was confirmed by histological evaluation as well as serum urea and creatinine levels that kidney damage due to SA toxicity can be modulated by zingerone administration.

Spleen Toxicity of Organophosphorus Flame Retardant TDCPP in Mice and the Related Mechanisms

Tris(1,3-dichloro-2-propyl) phosphate (TDCPP) is an organophosphorus flame retardant that has been utilized in recent years as a primary replacement for polybrominated diphenyl ethers (PBDEs) in a wide variety of fire-sensitive applications. However, the impact of TDCPP on the immune system has not been fully determined. As the largest secondary immune organ in the body, the spleen is considered to be an important study endpoint for determining immune defects in the body. The aim of this study is to investigate the effect of TDCPP toxicity on the spleen and its possible molecular mechanisms. In this study, for 28 consecutive days, TDCPP was administered intragastrically (i.g), and we assessed the general condition of mice by evaluating their 24 h water and food intake. Pathological changes in spleen tissues were also evaluated at the end of the 28-day exposure. To measure the TDCPP-induced inflammatory response in the spleen and its consequences, the expression of the critical players in the NF-κB pathway and mitochondrial apoptosis were detected. Lastly, RNA-seq was performed to identify the crucial signaling pathways of TDCPP-induced splenic injury. The results showed that TDCPP intragastric exposure triggered an inflammatory response in the spleen, likely through activating the NF-κB/IFN-γ/TNF-α/IL-1β pathway. TDCPP also led to mitochondrial-related apoptosis in the spleen. Further RNA-seq analysis suggested that the TDCPP-mediated immunosuppressive effect is associated with the inhibition of chemokines and the expression of their receptor genes in the cytokine-cytokine receptor interaction pathway, including four genes of the CC subfamily, four genes of the CXC subfamily, and one gene of the C subfamily. Taken together, the present study identifies the sub-chronic splenic toxicity of TDCPP and provides insights on the potential mechanisms of TDCPP-induced splenic injury and immune suppression.

Arsenic and Diabetes Mellitus: A Putative Role for the Immune System

Diabetes mellitus (DM) is an enormous public health issue worldwide. Recent data suggest that chronic arsenic exposure is linked to the risk of developing type 1 and type 2 DM, albeit the underlying mechanisms are unclear. This review discusses the role of the immune system as a link to possibly explain some of the mechanisms of developing T1DM or T2DM associated with arsenic exposure in humans, animal models, and in vitro studies. The rationale for the hypothesis includes: (1) Arsenic is a well-recognized modulator of the immune system; (2) arsenic exposures are associated with increased risk of DM; and (3) dysregulation of the immune system is one of the hallmarks in the pathogenesis of both T1DM and T2DM. A better understanding of DM in association with immune dysregulation and arsenic exposures may help to understand how environmental exposures modulate the immune system and how these effects may impact the manifestation of disease.

Arsenic exposure and prevalence of human papillomavirus in the US male population

Arsenic is a known carcinogen and is naturally available in earth's crust. Inorganic arsenic is an environmental pollutant with immunosuppressive properties. Human papillomavirus (HPV) is considered one of the most common sexually transmitted diseases in the United States. HPV is linked to several types of cancers in males, including oral, anal, and penile cancer. However, limited information is available on the effect of arsenic on HPV in males. The purpose of this study was to examine the association of urinary arsenic species (speciated and total) and the prevalence of HPV infection in the male population. HPV prevalence in males was analyzed using the 2013-2014 and 2015-2016 National Health and Nutrition Examination Survey (NHANES) dataset. Logistic regression analysis was used to examine associations of seven types of urinary arsenic species (arsenous acid, arsenic acid, arsenobetaine, arsenocholine, dimethylarsinic acid (DMA), monomethylarsonic acid (MMA), total arsenic acid) with HPV risk for male participants aged 18-59 years (N = 1516). Demographic characteristics were included in the logistic regression model for each arsenic variable. All statistical analyses were conducted by using the software R (version 4.2.0). Increasing DMA was positively associated with the prevalence of low-risk HPV (odds ratio (OR): 1.075, 95% confidence interval (CI): 1.025, 1.128) in addition to the sum of total toxic arsenic species (TUA1) including arsenous acid, arsenic acid, DMA, and MMA (OR: 1.068, 95% CI: 1.022, 1.116). High-risk HPV strains were found to be positively associated with arsenic acid (OR: 1.806, 95% CI: 1.134, 2.876) and total arsenic minus the sum of the two organic arsenic species arsenobetaine and arsenocholine (TUA2) at quartile 3 (Q3) level (OR: 1.523, 95% CI: 1.102, 2.103). The logistic regression models also showed that race and marital status were significant factors related to high-risk HPV. Our study reported that DMA and TUA1 are associated with low-risk HPV and arsenic acid is associated with high-risk HPV infections in males. Future research is required to confirm or refute this finding.

Association between arsenic exposure and inflammatory cytokines and C-reaction protein: A systematic review and meta-analysis

BACKGROUND

Previous studies have reported controversial results on levels of inflammatory cytokines in patients with arsenic exposure. This study aims to evaluate the associations between arsenic exposure and inflammatory cytokines and C-reaction protein (CRP).

METHODS

We searched the databases including PubMed, Embase, Web of Science, and China national knowledge infrastructure (CNKI) for studies reporting levels of cytokines and CRP in patients with arsenic exposure compared to the controls. The retrieval time was from January 2000 to September 2022.

RESULTS

13 observational studies involving 1665 arsenic exposed and 1091 unexposed individuals were included. Among these studies, 6 from China, 4 from India, 2 from Bangladesh and 1 from Turkey. Our result showed that interleukin (IL)-6, IL-8, and IL-12 levels were significantly higher in arsenic-exposed individuals compared to the control group, IL-2 level was significantly lower, and Tumor necrosis factor-α, Interferon-γ, CRP, and IL-10 levels were not changed. After sensitivity analyses, tumor necrosis factor-α and Interferon-γ levels were significantly higher in arsenic-exposed individuals compared to the control group. High heterogeneity was detected in most studies.

CONCLUSION

Many cytokines (such as IL-6, IL-8, and IL-12) have altered in individuals with arsenic exposure, this indicates arsenic exposure could trigger the cell-mediated inflammatory response. Regular examining immune function (such as inflammatory cytokines) in individuals with the risk of arsenic exposure is important to human health.

Systemic maternal inflammation promotes ASD via IL-6 and IFN-γ

Autism spectrum disorder (ASD) is a neurological disorder that manifests during early development, impacting individuals through their ways of communicating, social behaviors, and their ability to perform day-to-day activities. There have been different proposed mechanisms on how ASD precipitates within a patient, one of which being the impact cytokines have on fetal development once a mother's immune system has been activated (referred to as maternal immune activation, MIA). The occurrence of ASD has long been associated with elevated levels of several cytokines, including interleukin-6 (IL-6) and interferon gamma (IFN-γ). These proinflammatory cytokines can achieve high systemic levels in response to immune activating pathogens from various extrinsic sources. Transfer of cytokines such as IL-6 across the placental barrier allows accumulation in the fetus, potentially inducing neuroinflammation and consequently altering neurodevelopmental processes. Individuals who have been later diagnosed with ASD have been observed to have elevated levels of IL-6 and other proinflammatory cytokines during gestation. Moreover, the outcome of MIA has been associated with neurological effects such as impaired social interaction and an increase in repetitive behavior in animal models, supporting a mechanistic link between gestational inflammation and development of ASD-like characteristics. The present review attempts to provide a concise overview of the available preclinical and clinical data that suggest cross-talk between IL-6 and IFN-γ through both extrinsic and intrinsic factors as a central mechanism of MIA that may promote the development of ASD.

Curcumin antagonizes inflammation and autophagy induced by arsenic trioxide through immune protection in duck spleen

Arsenic is a toxic heavy metal widely found in the natural environment and has adverse effects on the health of waterfowl and human. Curcumin (CUR), a natural pigment of the golden spice turmeric, exhibits excellent anti-tumor, anti-inflammatory and anti-oxidant activities. But the effects of CUR on duck spleen exposed to arsenic remain largely unknown. In this study, 75 ducks were divided randomly into Control, L-ATO, M-ATO, H-ATO and CUR + H-ATO groups to systematically analyze the underlying role of CUR. The results showed that arsenic trioxide (ATO) led to growth retardation of ducks, hyaline degeneration and sparse cell arrangement on their spleen. And in the ATO-exposed ducks, the levels of immunoglobulins (Ig; IgA, IgG, IgM) in the serum and the expression of autophagy-related genes (Atg5, P62, LC3I, LC3II, LC3II/I, Beclin-1) were significantly upregulated compared with the control ducks. Moreover, ATO also activated NF-κB signal pathway and upregulated the expression of pro-inflammatory cytokines (TNF-α, IFN-γ, IL-1β, IL-2, IL-18). Meanwhile, application of CUR alleviated the ATO toxicity with the release of growth inhibition, and the reduced hyaline degeneration and distortion of the spleen capsule. CUR also suppressed ATO-induced NF-κB activation, pro-inflammatory cytokine addition and expression of autophagy-related genes. Overall, these results suggested that CUR might exert a protective effect against ATO-induced immunosuppression in ducks via anti-inflammation and autophagy restoring.

Arsenic as an immunotoxicant

Arsenic is world-wide contaminant to which millions of people are exposed. The health consequences of arsenic exposure are varied, including cancer, cardiometabolic disease, and respiratory disorders. Arsenic is also toxic to the immune system, which may link many of the pathologies associated with arsenic exposure. The immune system can be classified into two interconnected arms: the innate and the adaptive immune responses. Herein, we discuss the effects of arsenic on key cell types within each of these arms, highlighting both in vitro and in vivo responses. These cells include macrophages, neutrophils, dendritic cells, and both B and T lymphocytes. Furthermore, we will explore data from human populations where altered immune status is implicated in disease and identify several data gaps where research is needed to complete our understanding of the immunotoxic effects of arsenic.

Role of N6-methyladenosine RNA modification in the imbalanced inflammatory homeostasis of arsenic-induced skin lesions

This study aimed to investigate the effect of N6-methyladenosine (m⁶ A) modification in modulating inflammatory homeostasis of arsenic (As)-induced skin lesions. Our bioinformatic analysis revealed abnormal expression of m⁶ A RNA methylation regulators and cytokines in the arsenic-exposed population. In human keratinocytes, arsenite increased the levels of m⁶ A methylation by upregulating the RNA methyltransferase like 3 (METTL3), mediating the disordered secretion of indicators that reflect inflammatory homeostasis (IL-6, IL-17, and IL-10). The indicators reflecting arsenic-induced skin lesions (Krt1 and Krt10) were also significantly elevated, which contributed to the occurrence of skin lesions. Our results also confirmed the association between METTL3 with inflammatory homeostasis and arsenic-induced skin lesions using arsenic-exposed human skin samples. In the arsenic-exposed group, the upregulation of METTL3 exacerbated the increase in cytokine levels (IL-6, IL-17, and IL-10), which was associated with the upregulation of keratins (Krt1 and Krt10). In addition, significant correlations among these factors corroborate the theoretical links. Finally, alteration of the m⁶ A levels via knockdown or enhancement of the METTL3 protein could antagonize or aggravate arsenite-induced imbalanced inflammatory homeostasis and human keratinocyte damage in HaCaT cells. Collectively, our study reveals some evidence that regulation of m⁶ A modification plays an important role in arsenic-induced skin lesions, which provide a new perspective on the mechanism of arsenite-induced imbalanced inflammatory homeostasis in the field of RNA epigenetics.

Phytochemicals in the Management of Arsenic Toxicity

Arsenic toxicity is a major concern due to its deleterious consequences for human health. Rapid industrialization also has weakened the quality of the environment by introducing pollutants that may disrupt balanced ecosystems, adversely and irreversibly impacting humans, plants, and animals. Arsenic, an important toxicant among all environmental hazards, can lead to several detrimental effects on cells and organs, impacting the overall quality of life. Nevertheless, arsenic also has a rich history as a chemotherapeutic agent used in ancient days for the treatment of diseases such as malaria, cancer, plague, and syphilis when other chemotherapeutic agents were yet to be discovered. Arsenicosis-mediated disorders remain a serious problem due to the lack of effective therapeutic options. Initially, chelation therapy was used to metabolically eliminate arsenic by forming a complex, but adverse effects limited their pharmacological use. More recently, plant-based products have been found to provide significant relief from the toxic effects of arsenic poisoning. They act by different mechanisms affecting various cellular processes. Phytoconstituents such as curcumin, quercetin, diallyl trisulfide, thymoquinone, and others act via various molecular pathways, primarily by attenuating oxidative damage, membrane damage, DNA damage, and proteinopathies. Nonetheless, most of the phytochemicals reviewed here protect against the adverse effects of metal or metalloid exposure, supporting their consideration as alternatives to chelation therapy. These agents, if used prophylactically and in conjunction with other chemotherapeutic agents, may provide an effective approach for management of arsenic toxicity. In a few instances, such strategies like coadministration of phytochemicals with a known chelating agent have led to more pronounced elimination of arsenic from the body with lesser off-site adverse effects. This is possible because combination treatment ensures the use of a reduced dose of chelating agent with a phytochemical without compromising treatment. Thus, these therapies are more practical than conventional therapeutic agents in ameliorating arsenic-mediated toxicity. This review summarizes the potential of phytochemicals in alleviating arsenic toxicity on the basis of available experimental and clinical evidence.

Curcumin alleviates arsenic-induced injury in duck skeletal muscle via regulating the PINK1/Parkin pathway and protecting mitochondrial function

Arsenic is a well-known environmental pollutant due to its toxicity, which can do harm to animals and human. Curcumin is a polyphenolic compound derived from turmeric, commonly accepted to have antioxidant properties. However, whether curcumin can ameliorate the damage caused by arsenic trioxide (ATO) in duck skeletal muscle remains largely unknown. Therefore, the present study aims to investigate the potential molecular mechanism of curcumin against ATO-induced skeletal muscle injury. The results showed that treating with curcumin could attenuate body weight loss induced by ATO and reduced arsenic content accumulation in the skeletal muscle of duck. Curcumin was also able to alleviated the oxidative stress triggered by ATO, which was manifested by the increase of T-AOC and SOD, and MDA decrease. Moreover, we observed that curcumin could ease mitochondrial damage and vacuolate degeneration of nucleus. Our further investigation found that ATO disrupted normal mitochondrial fission/fusion (Drp1, OPA1, Mfn1/2) and restrained mitochondrial biogenesis (PGC-1α, Nrf1/2, TFAM), while curcumin could promote mitochondrial fusion and activated PGC-1α pathway. Furthermore, curcumin was found that it could not only reduce the mRNA and protein levels of mitophagy (PINK1, Parkin, LC3, p62) and pro-apoptotic genes (p53, Bax, Caspase-3, Cytc), but also increased the levels of anti-apoptotic genes (Bcl-2). In conclusion, curcumin was able to alleviate ATO-induced skeletal muscle damage by improving mitophagy and preserving mitochondrial function, which can serve as a novel strategy to take precautions against ATO toxicity.

Sub-chronic low-dose arsenic in rice exposure induces gut microbiome perturbations in mice

Long-term consumption of arsenic-contaminated rice has become a public health issue that urgently needs to be addressed. In this study, mice were exposed to arsenic in rice (low dose, 0.91 mg/kg; medium dose, 9.1 mg/kg) for 30 days and 60 days, respectively, and the effects on pathological structures of spleen and skin, as well as the structure of the fecal microbiome were examined. The findings revealed dose/time cumulative effects on pathological changes, with even a low dose exposure for 30 days causing destruction of splenic follicular structure and thickening of dermal keratinized and epidermal layers. The Firmicutes/Bacteroidetes ratio in the community and the positive/negative ratio in network links were higher in arsenic groups, suggesting that arsenic resulted in a less healthy and unstable microbiome for the host. Thus lifetime consumption of arsenic in rice may have potential health effects on humans and must be carefully assessed to safeguard human health. Furthermore, in arsenic groups, arsenic-resistant bacteria or arsenic hazards remediation bacteria changed to be the dominant bacteria and acted as the core bacteria in the network modules. Some microbial arsenic transforming genes (arsC, arsR, arsA, ACR3, and aoxB) differed, indicating that the gut microbiome changed to withstand arsenic stress. Furthermore, Faecalibaculum, Lachnospiraceae_NK4A136_group, Angelakisella, Ruminiclostridium, and Desulfovibrionaceae are positively associated with arsenic dosage and may be useful in the early detection of arsenicals.

Chrysin attenuates sodium arsenite-induced nephrotoxicity in rats by suppressing oxidative stress and inflammation

BACKGROUND

We aimed to study the beneficial property of chrysin (CHR) by targeting its antioxidant and anti-inflammatory effects on nephrotoxicity induced by sodium arsenite (SA).

MATERIALS & METHODS

We have used the 35 male Wistar rats in five equal groups (n = 7). Normal saline in (5 ml/kg; p.o.; 21 days) was given to the control group. Sodium arsenite (10 mg/kg; p.o.; 14 days) was given to the SA group. CHR (25, 50 and 100 mg/kg; p.o.; 21 days) and SA (10 mg/kg; p.o.; 14 days from the 7th day of the experiment) was given to the SA + CHR 25, 50 and 100 groups. On the 22nd day of the experiment, the animals' bloods and kidneys were taken, and then we have performed functional, biochemical and histological assessment.

RESULTS

CHR pre- and alongside administration (more potently at dose of 100 mg/kg) with SA reduced the SA-induced alterations in serum creatinine and blood urine nitrogen levels. Increased levels of protein carbonyl, myeloperoxidase, malondialdehyde and nitric oxide in kidney tissue were decreased by CHR treatment. CHR administration increased the levels of glutathione and activities of glutathione peroxidase, catalase and superoxide dismutase in renal tissue. Moreover, treatment with CHR reduced the levels of inflammatory mediators including interleukin 1 beta and tumor necrosis factor alpha in renal tissue. The renal histological lesions induced SA were mitigated by CHR treatment in dose dependent manner.

CONCLUSION

The results of present study suggested that administration of CHR before and alongside with SA attenuated the renal toxic effects of SA via antioxidative stress and anti-inflammatory effects.

6-Gingerol attenuates ventilator-induced lung injury via anti-inflammation and antioxidative stress by modulating the PPARγ/NF-κBsignalling pathway in rats

Although mechanical ventilation (MV) is indispensable to life-support therapy in critically ill patients, it may promote or aggravatelunginjury known asventilator-inducedlunginjury(VILI). 6-Gingerol is the principal ingredient of ginger with potential anti-inflammatory and antioxidant properties in various diseases. Nevertheless, the role and mechanism of 6-gingerol in the process of VILI has not been explicitly investigated. In the study, we found that pre-treatment with 6-gingerol significantly improved the histological changes and pulmonary oedema, inhibited neutrophil accumulation and the release of early pro-inflammatory cytokines and MPO, and reduced oxidative stress reactions after high MV. Moreover, 6-gingerol treatment also increased PPARγ expression and decreased NF-κB activation in rats subjected to high MV. Furthermore, GW9662, a specific PPARγ inhibitor, was demonstrated to activatethe NF-κB pathway and cancele the protective role of 6-gingerol in VILI. This indicates that 6-gingerol exerted anti-inflammatory and antioxidative stress effects in VILI by activating PPARγ and inhibiting the NF-κBsignalling pathway.

Mechanisms involved in the possible protective effect of chrysin against sodium arsenite-induced liver toxicity in rats

Arsenic as a one of the most important toxic metals could induce hepatotoxicity. Previous reports revealed the significance of oxidative stress in promoting of arsenic-induced liver toxicity. The aim of the present investigation is to evaluate the effect of chrysin (CHR), a natural flavonoid with potent antioxidant activity, against sodium arsenite (SA)-induced hepatotoxicity. Thirty male Wistar rats were divided into four groups: Group 1: received normal saline (2 ml/kg/day, orally for 21 days), Group 2: received SA (10 mg/kg/day, orally for 14 days), Group 3, 4 and 5: received CHR (25, 50 and 100 mg/kg/day, respectively, orally for 21 days) and SA (10 mg/kg/day, orally for 14 days) from the 7th day. Serum levels of alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase were evaluated. Moreover, liver glutathione peroxidase and myeloperoxidase activity as well as levels of protein carbonylation, malondialdehyde, glutathione, catalase, nitric oxide, superoxide dismutase, tumor necrosis factor-α and interleukin-1β were evaluated. Moreover, histological evaluation was done. Our results revealed that treatment with CHR (more potentially at the dose of 100 mg/kg/day) before and alongside with SA significantly mitigated the SA-induced hepatotoxicity. Also, the hepatoprotective effect of CHR was verified by the histological evaluation of the liver. The results of current study demonstrated that CHR (100 mg/kg/day) could mitigate the oxidative stress and inflammation induced by SA in liver tissue.