Spatial distribution and comparative analysis of Aconitum alkaloids in Fuzi using DESI-MSI and UHPLC-QTOF-MS.

Aconitum L. poisoning is a major type of poisoning caused by herbal medicines in many countries. However, despite its toxicity, Aconitum L. is still used because of its therapeutic value. Fuzi, the lateral root of Aconitum L., is one of the most important pharmacological parts. It is necessary for rational medication to figure out the types and contents of toxic Aconitum alkaloids (AAs) in Fuzi and its processed products. The present study aims to investigate the spatial distribution of toxic AAs in Fuzi and the quantification of AAs in various processing products through mass spectrometry methods. In this study, desorption electrospray ionization mass spectrometry imaging (DESI-MSI) was used to directly image the sections of raw Fuzi. The results showed a high content of diester alkaloids (DAs) and a relatively uniform distribution in the sections, while the content of monoester alkaloids (MAs) was low and uneven in the sections, distributed in the cortex, epidermis, vascular column, and other parts of the tissues. The content of non-ester alkaloids (NAs) was relatively minimum, and most of the NAs were distributed in the vascular column and the tightly connected cortex of the tissue. To further investigate the difference between raw and processed Fuzi, 60 known compounds were identified using UHPLC-QTOF-MS. The total contents of alkaloids in 7 processed Fuzi were lower than that in Shengfupian (SFP). Paofupian (PFP), Paotianxiong (PTX), Paofupian (PFP*), Danfupian (DFP), and Shufupian (SFP*) were the least similar. Zhengfupian (ZFP) and Chaofupian (CFP) had significantly reduced toxicity and increased efficacy compared with other processed products because the contents of active alkaloids in other processed products were also reduced. Understanding the distribution of metabolites and the composition changes after processing can guide users and herbal manufacturers to carefully choose the relatively safe and better therapeutic species of Fuzi. The information gathered from this study can contribute towards the improved and effective management of therapeutically important, nonetheless toxic, drugs such as Aconitum L.

Sesquiterpenes from two Compositae plants as promising inhibitors to nuclear hormone receptor 3 of Tribolium castaneum.

Essential oils (EOs) and their volatile secondary metabolites have been proved to be effective on storage pests control, while restricted on the application due to unclear mechanism. Molecular dynamics (MD) simulations and binding free energies analysis provided an effective approach to reveal mechanism on conformational calculation. In this work, the insecticidal and repellent capacities of Praxelis clematidea and Ageratum houstonianum oils and their main components identified by gas chromatography-mass spectrometry (GC-MS) were scientifically measured. Interestingly, P. clematidea oil exhibited strong fumigant toxicity against Tribolium castaneum (LC50 = 7.07 mg/L air). Moreover, two EOs exhibited over 80% repellent rate against T. castaneum at the highest concentration of 78.63 nL/cm2. Furthermore, hundreds of enzymes related to the regulation of biological processes of T. castaneum were screened to explore the underlying molecular mechanism and develop promising insecticides. Besides, top hits were subjected to MD simulations and binding free energies analysis to elucidate complex inter-molecular stability and affinity over simulated time. The results demonstrated that isolongifolene, δ-cadinene, ß-caryophyllene and caryophyllene oxide were prioritized as they were establishing conserved and stable interactions with residues of nuclear hormone receptor 3 (TcHR3) of T. castaneum, which suggested that the four sesquiterpenes have potential to be promising insecticides on storage pests control.

Lethality of Zinc Oxide Nanoparticles Surpasses Conventional Zinc Oxide via Oxidative Stress, Mitochondrial Damage and Calcium Overload: A Comparative Hepatotoxicity Study.

Zinc oxide nanoparticles (ZnO NPs) with high bioavailability and excellent physicochemical properties are gradually becoming commonplace as a substitute for conventional ZnO materials. The present study aimed to investigate the hepatotoxicity mechanism of ZnO NPs and traditional non-nano ZnO particles, both in vivo and in vitro, and identify the differences in their toxic effects. The results showed that the extent and conditions of zinc ion release from ZnO NPs were inconsistent with those of ZnO. The RNA-seq results revealed that the expression quantity of differentially expressed genes (DEGs) and differentially expressed transcripts (DETs) affected by ZnO NPs was more than in ZnO, and the overall differences in genes or transcripts in the ZnO NPs group were more pronounced than in the ZnO group. Furthermore, the cell inactivation, oxidative stress, mitochondrial damage, and intracellular calcium overload induced by ZnO NPs were more serious than ZnO in HepG2 cells. Moreover, compared with traditional ZnO, the rat liver damage induced by ZnO NPs was more significant, with evidence of higher AST and ALT levels, weaker antioxidant capacity, and more serious histopathological damage (p < 0.05). In summary, the hepatotoxicity of ZnO NPs was more serious than that of conventional ZnO, which is helpful to understand the hepatotoxicity mechanism of Zn compounds in different states and improve the risk assessment of novel nano ZnO products in a variety of applications.

Curcumin Ameliorates Copper-Induced Neurotoxicity Through Inhibiting Oxidative Stress and Mitochondrial Apoptosis in SH-SY5Y Cells.

Impaired homeostasis of copper has been linked to different pathophysiological mechanisms in neurodegenerative diseases and oxidative injury has been proposed as the main mechanism. This study aims to use curcumin, a widely used antioxidative and anti-apoptotic agent, to exert the neuroprotective effect against copper in vitro and illuminate the underlying mechanism. The effect of curcumin was examined by using a cell counting kit-8 assay, flow cytometry, immunofluorescence, spectrophotometer, and western blot. Results revealed that after pretreatment with curcumin for 3 h, copper-induced toxicity and apoptosis show a significant decline. Further experiments showed that curcumin not only decreased the production of ROS and MDA but also increased the activities of the ROS scavenging enzymes SOD and CAT. Moreover, curcumin treatment alleviated the decrease in mitochondrial membrane potential and the nuclear translocation of cytochrome c induced by copper. The protein levels of pro-caspase 3, pro-caspase 9, and PARP1 were up-regulated and the Bax/Bcl-2 ratio was down-regulated in the presence of curcumin. Taken together, our study demonstrates that curcumin has neuroprotective properties against copper in SH-SY5Y cells and the potential mechanisms might be related to oxidative stress and mitochondrial apoptosis.

DIDS inhibits overexpression BAK1-induced mitochondrial apoptosis through GSK3ß/ß-catenin signaling pathway.

Bcl-2 homologous antagonist/killer (BAK1) is a critical regulator of mitochondrial apoptosis. Although upregulation of BAK1 induces apoptosis has been established, the underlying molecular mechanism is far from clear. 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS), an organic anion used as a blocker of anion exchangers and chloride channels, has been proved to rescue cell apoptosis both in vitro and in vivo. However, whether DIDS can inhibit BAK1-induced mitochondrial apoptosis remains undefined. Thus, this study aimed to explore whether DIDS could protect BAK1-induced apoptosis through GSK3ß/ß-catenin signaling pathway. The results showed overexpression BAK1 in 293T cells induced mitochondrial apoptosis accompanied by increasing the expression levels of cleaved caspase-9, -3, poly (ADP-ribose) polymerase (PARP) and reducing the MMP. Furthermore, overexpression BAK1 decreased the expression levels of Ser9-GSK3ß and ß-catenin. In addition, lithium chloride (LiCl), an activator of Wnt/ß-catenin signaling pathway, markedly attenuated overexpression BAK1-induced mitochondrial apoptosis by restoring the expression levels of Ser9-GSK3ß and ß-catenin. Finally, DIDS absolutely abolished overexpression BAK1-mediated mitochondrial apoptosis through recovering the expression levels of Ser9-GSK3ß and ß-catenin. Taken together, our results reveal that DIDS blocks overexpression BAK1-induced mitochondrial apoptosis through GSK3ß/ß-catenin pathway.

TCS2 Increases Olaquindox-Induced Apoptosis by Upregulation of ROS Production and Downregulation of Autophagy in HEK293 Cells.

Olaquindox, a feed additive, has drawn public attention due to its potential mutagenicity, genotoxicity, hepatoxicity and nephrotoxicity. The purpose of this study was to investigate the role of tuberous sclerosis complex (TSC2) pathways in olaquindox-induced autophagy in human embryonic kidney 293 (HEK293) cells. The results revealed that olaquindox treatment reduced the cell viability of HEK293 cells and downregulated the expression of TSC2 in a dose- and time-dependent manner. Meanwhile, olaquindox treatment markedly induced the production of reactive oxygen species (ROS), cascaded to autophagy, oxidative stress, and apoptotic cell death, which was effectively eliminated by the antioxidant N-acetylcysteine (NAC). Furthermore, overexpression of TSC2 attenuated olaquindox-induced autophagy in contrast to inducing the production of ROS, oxidative stress and apoptosis. Consistently, knockdown of TSC2 upregulated autophagy, and decreased olaquindox-induced cell apoptosis. In conclusion, our findings indicate that TSC2 partly participates in olaquindox-induced autophagy, oxidative stress and apoptosis, and demonstrate that TSC2 has a negative regulation role in olaquindox-induced autophagy in HEK293 cells.

GADD45a Regulates Olaquindox-Induced DNA Damage and S-Phase Arrest in Human Hepatoma G2 Cells via JNK/p38 Pathways.

Olaquindox, a quinoxaline 1,4-dioxide derivative, is widely used as a feed additive in many countries. The potential genotoxicity of olaquindox, hence, is of concern. However, the proper mechanism of toxicity was unclear. The aim of the present study was to investigate the effect of growth arrest and DNA damage 45 alpha (GADD45a) on olaquindox-induced DNA damage and cell cycle arrest in HepG2 cells. The results showed that olaquindox could induce reactive oxygen species (ROS)-mediated DNA damage and S-phase arrest, where increases of GADD45a, cyclin A, Cdk 2, p21 and p53 protein expression, decrease of cyclin D1 and the activation of phosphorylation-c-Jun N-terminal kinases (p-JNK), phosphorylation-p38 (p-p38) and phosphorylation-extracellular signal-regulated kinases (p-ERK) were involved. However, GADD45a knockdown cells treated with olaquindox could significantly decrease cell viability, exacerbate DNA damage and increase S-phase arrest, associated with the marked activation of p-JNK, p-p38, but not p-ERK. Furthermore, SP600125 and SB203580 aggravated olaquindox-induced DNA damage and S-phase arrest, suppressed the expression of GADD45a. Taken together, these findings revealed that GADD45a played a protective role in olaquindox treatment and JNK/p38 pathways may partly contribute to GADD45a regulated olaquindox-induced DNA damage and S-phase arrest. Our findings increase the understanding on the molecular mechanisms of olaquindox.

Quinocetone triggered ER stress-induced autophagy via ATF6/DAPK1-modulated mAtg9a trafficking.

The present study is undertaken to explore quinocetone-induced autophagy and its possible mechanism. Western blotting and green fluorescence protein (GFP)-LC3 vector transfection were performed to determine the ratio of LC3 conversion and its subcellular localization. Results revealed that the quinocetone induced autophagy in time- and dose-dependent manners. Besides, we tested the expressions of immunoglobulin heavy chain binding protein (BiP) and C/EBP homologous protein (CHOP) and the transcription of BiP, HerpUD, and sec24D by western blotting and RT-PCR, respectively. Results showed that quinocetone also induced endoplasmic reticulum (ER) stress during quinocetone-induced autophagy. Furthermore, we observed the cleavage of ATF6, the phosphorylation of MRLC, and the expression of death-associated protein kinase (DAPK1) by western blotting; the transcription of DAPK1 by RT-PCR; and the subcellular localization of ATF6 and mAtg9 by immunofluorescence. These results suggest that quinocetone stimulates the MRLC-mediated mAtg9 trafficking, which is critical for autophagosome formation, via the ATF6 upregulated expression of DAPK1. Last, we generated ATF6 and DAPK1 stable knockdown HepG2 cell lines and found that the conversion ratios of LC3 were decreased upon the treatment of quinocetone. Together, we propose that quinocetone induces autophagy through ER stress signaling pathway-induced cytoskeleton activation.

Curcumin Ameliorates Furazolidone-Induced DNA Damage and Apoptosis in Human Hepatocyte L02 Cells by Inhibiting ROS Production and Mitochondrial Pathway.

Furazolidone (FZD), a synthetic nitrofuran derivative, has been widely used as an antibacterial and antiprotozoal agent. Recently, the potential toxicity of FZD has raised concerns, but its mechanism is still unclear. This study aimed to investigate the protective effect of curcumin on FZD-induced cytotoxicity and the underlying mechanism in human hepatocyte L02 cells. The results showed that curcumin pre-treatment significantly ameliorated FZD-induced oxidative stress, characterized by decreased reactive oxygen species (ROS) and malondialdehyde formation, and increased superoxide dismutase, catalase activities and glutathione contents. In addition, curcumin pre-treatment significantly ameliorated the loss of mitochondrial membrane potential, the activations of caspase-9 and -3, and apoptosis caused by FZD. Alkaline comet assay showed that curcumin markedly reduced FZD-induced DNA damage in a dose-dependent manner. Curcumin pre-treatment consistently and markedly down-regulated the mRNA expression levels of p53, Bax, caspase-9 and -3 and up-regulated the mRNA expression level of Bcl-2. Taken together, these results reveal that curcumin protects against FZD-induced DNA damage and apoptosis by inhibiting oxidative stress and mitochondrial pathway. Our study indicated that curcumin may be a promising combiner with FZD to reduce FZD-related toxicity in clinical applications.

ML-7 amplifies the quinocetone-induced cell death through akt and MAPK-mediated apoptosis on HepG2 cell line.

The study aims at evaluating the combination of the quinocetone and the ML-7 in preclinical hepatocellular carcinoma models. To this end, the effect of quinocetone and ML-7 on apoptosis induction and signaling pathways was analyzed on HepG2 cell lines. Here, we report that ML-7, in a nontoxic concentration, sensitized the HepG2 cells to quinocetone-induced cytotoxicity. Also, ML-7 profoundly enhances quinocetone-induced apoptosis in HepG2 cell line. Mechanistic investigations revealed that ML-7 and quinocetone act in concert to trigger the cleavage of caspase-8 as well as Bax/Bcl-2 ratio up-regulation and subsequent cleavage of Bid, capsases-9 and -3. Importantly, ML-7 weakened the quinocetone-induced Akt pathway activation, but strengthened the phosphorylation of p-38, ERK and JNK. Further treatment of Akt activator and p-38 inhibitor almost completely abolished the ML-7/quinocetone-induced apoptosis. In contrast, the ERK and JNK inhibitor aggravated the ML-7/quinocetone-induced apoptosis, indicating that the synergism critically depended on p-38 phosphorylation and HepG2 cells provoke Akt, ERK and JNK signaling pathways to against apoptosis. In conclusion, the rational combination of quinocetone and ML-7 presents a promising approach to trigger apoptosis in hepatocellular carcinoma, which warrants further investigation.

Curcumin attenuates quinocetone-induced oxidative stress and genotoxicity in human hepatocyte L02 cells.

Quinocetone (QCT), a new quinoxaline 1,4-dioxides, has been used as antimicrobial feed additive in China. Potential genotoxicity of QCT was concerned as a public health problem. This study aimed to investigate the protective effect of curcumin on QCT-induced oxidative stress and genotoxicity in human hepatocyte L02 cells. Cell viability and intracellular reactive oxygen species (ROS), biomarkers of oxidative stress including superoxide dismutase (SOD) activity and glutathione (GSH) level were measured. Meanwhile, comet assay and micronucleus assay were carried out to evaluate genotoxicity. The results showed that, compared to the control group, QCT at the concentration ranges of 2-16 µg/mL significantly decreased L02 cell viability, which was significantly attenuated with curcumin pretreatment (2.5 and 5 µM). In addition, QCT significantly increased cell oxidative stress, characterized by increases of intracellular ROS level, while decreased endogenous antioxidant biomarkers GSH level and SOD activity (all p < 0.05 or 0.01). Curcumin pretreatment significantly attenuated ROS formation, inhibited the decreases of SOD activity and GSH level. Furthermore, curcumin significantly reduced QCT-induced DNA fragments and micronuclei formation. These data suggest that curcumin could attenuate QCT-induced cytotoxicity and genotoxicity in L02 cells, which may be attributed to ROS scavenging and anti-oxidative ability of curcumin. Importantly, consumption of curcumin may be a plausible way to prevent quinoxaline 1,4-dioxides-mediated oxidative stress and genotoxicity in human or animals.

S2 subunit plays a critical role in pathogenesis of TW-like avian coronavirus infectious bronchitis virus.

To investigate the critical role of the S gene in determining pathogenesis of TW-like avian infectious bronchitis virus (IBV), we generated two recombinant IBVs (rGDaGD-S1 and rGDaGD-S2) by replacing either the S1 or S2 region of GD strain with the corresponding regions from an attenuated vaccine candidate aGD strain. The virulence and pathogenicity of these recombinant viruses was assessed both in vitro and in vivo. Our results indicated the mutations in the S2 region led to decreased virulence, as evidenced by reduced virus replication in embryonated chicken eggs and chicken embryonic kidney cells as well as observed clinical symptoms, gross lesions, microscopic lesions, tracheal ciliary activity, and viral distribution in SPF chickens challenged with recombinant IBVs. These findings highlight that the S2 subunit is a key determinant of TW-like IBV pathogenicity. Our study established a foundation for future investigations into the molecular mechanisms underlying IBV virulence.

Oxidative stress-related canonical pyroptosis pathway, as a target of liver toxicity triggered by zinc oxide nanoparticles.

Zinc oxide nanoparticles (ZnO NPs) have been widely used in the fields of daily necessities, clinical diagnosis, drug delivery and agricultural production. The improper use of ZnO NPs could pose a risk to ecological environment and public health. Liver has been known as a critical toxic target of ZnO NPs. However, the question whether ZnO NPs lead to hepatocyte death through pyroptosis has not been answered yet, and the effect of oxidative stress on ZnO NPs-induced pyroptosis remains a mystery. We revealed that ZnO NPs disrupted zinc homeostasis and induced oxidative stress impairment in rat liver. Meanwhile, ZnO NPs triggered the assembly of NLRP3-ASC-Caspase-1 inflammatory complex and pyroptosis in both rat liver and HepG2 cells, further causing the activation of GSDMD, promoting the leakage of inflammatory cytokines including IL-1ß and IL-18. Importantly, the inhibition of oxidative stress was found to provide protection against pyroptosis in hepatocyte exposed to ZnO NPs. We identified a novel mechanism of liver damage induced by ZnO NPs, demonstrating the activation of canonical Caspase-1-dependent pyroptosis pathway and clarifying the protection of antioxidation against pyroptosis damage. Our discovery provided a support for risk assessment of ZnO NPs and target exploration for clinical treatment related to pyroptosis.

TFEB coordinates autophagy and pyroptosis as hepatotoxicity responses to ZnO nanoparticles.

Zinc oxide nanoparticles (ZnO NPs) have drawn serious concerns about their biotoxicity due to their extensive applications in biological medicine, clinical therapeutic, daily chemical production, food and agricultural additives. In our present study, we clarified hepatotoxic mechanism of ZnO NPs through investigating the crosstalk between autophagy and pyroptosis, a remaining enigma in hepatocyte stimulated by ZnO NPs. Based on the effects of autophagy intervention by Rapamycin (Rap) and 3-Methyladenine (3-MA), and the observation of pyroptosis morphology and related indexes, the autophagy and pyroptosis simultaneously initiated by ZnO NPs were interrelated and the autophagy characterized by autophagosome production and increased expression of autophagy proteins was identified as a protective response of ZnO NPs against pyroptosis. According to the analysis of protein expression and fluorescence localization, the NLRP3 inflammasome assemble and the classical Caspase-1/GSDMD-dependent pyroptosis induced by ZnO NPs was modulated by autophagy. In this process, the adjustment of TFEB expression and nuclear translocation by gene knockout and gene overexpression, further altered the tendency of ZnO NPs-induced pyroptosis via the regulation of autophagy and lysosomal biogenesis. The knockout of TFEB gene exacerbated the pyroptosis via autophagy elimination and lysosome inhibition. While the alleviation of NLRP3 generation and pyroptosis activation was observed after treatment of TFEB gene overexpression. Additionally, the siRNA interference confirmed that TRAF-6 was involved in the TFEB-mediated global regulation of autophagy-lysosome-pyroptosis in response to ZnO NPs. Accordingly, pyroptosis induced by ZnO NPs in hepatocyte could be significantly avoided by TFEB-regulated autophagy and lysosome, further providing new insights for the risk assessment and therapeutic strategy.

Paeoniflorin recued hepatotoxicity under zinc oxide nanoparticles exposure via regulation on gut-liver axis and reversal of pyroptosis.

The risks of Zinc oxide nanoparticles (ZnO NPs) applications in biological medicine, food processing industry, agricultural production and the biotoxicity brought by environmental invasion of ZnO NPs both gradually troubled the public due to the lack of research on detoxification strategies. TFEB-regulated autophagy-pyroptosis pathways were found as the crux of the hepatotoxicity induced by ZnO NPs in our latest study. Here, our study served as a connecting link between preceding toxic target and the following protection mechanism of Paeoniflorin (PF). According to a combined analysis of network pharmacology/molecular docking-intestinal microbiota-metabolomics first developed in our study, PF alleviated the hepatotoxicity of ZnO NPs from multiple aspects. The hepatic inflammatory injury and hepatocyte pyroptosis in mice liver exposed to ZnO NPs was significantly inhibited by PF. And the intestinal microbiota disorder and liver metabolic disturbance were rescued. The targets predicted by bioinformatics and the signal trend in subacute toxicological model exhibited the protectiveness of PF related to the SIRT1-mTOR-TFEB pathway. These evidences clarified multiple protective mechanisms of PF which provided a novel detoxification approach against ZnO NPs, and further provided a strategy for the medicinal value development of PF.

Targeting HMGB1 inhibits T-2 toxin-induced neurotoxicity via regulation of oxidative stress, neuroinflammation and neuronal apoptosis.

T-2 toxin, a food-derived mycotoxin, has been identified as a neurotoxin. Nonetheless, T-2 toxin-induced neuroinflammation has never been revealed. As an important therapeutic target for inflammatory diseases and cancers, the role of high mobility group B1 (HMGB1) in mycotoxin-mediated neurotoxicity remains a mystery. In current study, we found that PC12 cells were sensitive to trace amounts of T-2 toxin less than 12 ng/mL, distinguished by decreased cell viability and increased release of lactate dehydrogenase (LDH). Oxidative stress and mitochondrial damage were observed in PC12 cells, manifested as accumulation of oxidative stress products, up-regulation of Nrf2/HO-1 pathway and decrease of mitochondrial membrane potential (MMP), leading to mitochondria-dependent apoptosis. Meanwhile, we first discovered that tiny amounts of T-2 toxin triggered neuroinflammation directly, including raising the expression and translocation of NF-κB and promoting secretion of proinflammatory cytokines such as TNF-α, IL-6, IL-8 and IL-1ß. Most interestingly, the increased of HMGB1 was detected both inside and outside the cells. Conversely, HMGB1 siRNA reduced T-2 toxin-mediated oxidative stress, apoptosis and neuroinflammatory outbreak, accompanied by lessened caspase-3 and caspase-9, and decreased secretion of pro-inflammatory cytokines. Taken together, T-2 toxin-stimulated PC12 cells simultaneously displayed apoptosis and inflammation, whereas HMGB1 played a critical role in these neurotoxic processes.

Food-Origin Mycotoxin-Induced Neurotoxicity: Intend to Break the Rules of Neuroglia Cells.

Mycotoxins are key risk factors in human food and animal feed. Most of food-origin mycotoxins could easily enter the organism and evoke systemic toxic effects, such as aflatoxin B1 (AFB1), ochratoxin A (OTA), T-2 toxin, deoxynivalenol (DON), zearalenone (ZEN), fumonisin B1 (FB1), and 3-nitropropionic acid (3-NPA). For the last decade, the researches have provided much evidences in vivo and in vitro that the brain is an important target organ on mycotoxin-mediated neurotoxic phenomenon and neurodegenerative diseases. As is known to all, glial cells are the best regulator and defender of neurons, and a few evaluations about the effects of mycotoxins on glial cells such as astrocytes or microglia have been conducted. The fact that mycotoxin contamination may be a key factor in neurotoxicity and glial dysfunction is exactly the reason why we reviewed the activation, oxidative stress, and mitochondrial function changes of glial cells under mycotoxin infection and summarized the mycotoxin-mediated glial cell proliferation disorders, death pathways, and inflammatory responses. The purpose of this paper is to analyze various pathways in which common food-derived mycotoxins can induce glial toxicity and provide a novel perspective for future research on the neurodegenerative diseases.

Molecular Insights of Copper Sulfate Exposure-Induced Nephrotoxicity: Involvement of Oxidative and Endoplasmic Reticulum Stress Pathways.

The precise pathogenic mechanism in Cu exposure-cause nephrotoxicity remains unclear. This study investigated the underlying molecular mechanism of copper sulfate (CuSO4)-induced nephrotoxicity. Mice were treated with CuSO4 at 50, 100, 200 mg/kg/day or co-treated with CuSO4 (200 mg/kg/day) and 4-phenylbutyric acid (4-PBA, 100 mg/kg/day) for 28 consecutive days. HEK293 cells were treated with CuSO4 (400 µM) with or without superoxide dismutase, catalase or 4-PBA for 24 h. Results showed that CuSO4 exposure can cause renal dysfunction and tubular necrosis in the kidney tissues of mice. CuSO4 exposure up-regulated the activities and mRNA expression of caspases-9 and -3 as well as the expression of glucose-regulated protein 78 (GRP78), GRP94, DNA damage-inducible gene 153 (GADD153/CHOP), caspase-12 mRNAs in the kidney tissues. Furthermore, superoxide dismutase and catalase pre-treatments partly inhibited CuSO4-induced cytotoxicity by decreasing reactive oxygen species (ROS) production, activities of caspases-9 and -3 and DNA fragmentations in HEK293 cells. 4-PBA co-treatment significantly improved CuSO4-induced cytotoxicity in HEK293 cells and inhibited CuSO4 exposure-induced renal dysfunction and pathology damage in the kidney tissues. In conclusion, our results reveal that oxidative stress and endoplasmic reticulum stress contribute to CuSO4-induced nephrotoxicity. Our study highlights that targeting endoplasmic reticulum and oxidative stress may offer an approach for Cu overload-caused nephrotoxicity.

Identification of Plant Soot as Novel Safe Feed Additive: Evaluation of 90-Day Oral Toxicity and Prenatal Developmental Toxicity in Rats.

Plant soot, as a novel feed additive, could not only improve digestive function but also adsorb mycotoxins and inhibit bacterial infections. The subchronic toxicity and prenatal developmental effects of plant soot were studied for the first time. Our results indicated that there was no subchronic toxicity in the range of 2,000-50,000 mg/kg plant soot added in the feed, and there was no significant difference in reproductive function, embryo development, and teratogenicity between the pregnant rats exposed to 312.5, 1,250, and 5,000 mg/kg plant soot and the control group. The maximum no-observed effect level (NOEL) of supplemental dosage in feed could be set to 50,000 mg/kg, and the maximum intragastric NOEL could be set to 5,000 mg/kg, which preliminarily provided guidance on daily additive amount or clinical protocols for plant soot, as well as promoting the development and application of this harmless antibiotic substitutes.

Molecular mechanism of olaquindox-induced hepatotoxicity and the hepatic protective role of curcumin.

Olaquindox (OLA) is a chemosynthetic growth promoter, which could promote the treatment of bacterial infections and improve feed energy efficiency. Hepatotoxicity is still a poor feature associated with the adverse effects of OLA. The present study aimed to investigate the molecular mechanism of OLA-induced hepatotoxicity and the protective role of curcumin in mice and HepG2 cells. The result showed that representative biomarkers involved in mitochondrial pathway, p53 pathway, mitogen-activated protein kinase (MAPK) pathway, autophagy and antioxidant pathway were activated. Furthermore, curcumin attenuated OLA-induced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and liver damage in mice. In addition, cell viability of HepG2 was enhanced by curcumin pretreatment at 5, 10 and 20 µM. Meanwhile, curcumin markedly ameliorated OLA-induced oxidative stress, apoptosis and mitochondrial dysfunction. Moreover, curcumin pretreatment significantly up-regulated the expressions of nuclear factor erythroid-2-related factor 2 (Nrf2) and heme oxygenase-1(HO-1) and down-regulated the expressions of nuclear factor-kappaB (NF-kB) and p53 through reduced the nuclear translocation of NF-kB induced by OLA. In summary, our findings indicated that OLA-induced hepatotoxicity involved in mitochondrial apoptosis, autophagy, p53 pathway, Nrf2/HO-1 pathways, and curcumin regulated OLA-induced liver damage, oxidative stress and apoptosis via activation of Nrf2/HO-1 pathway and suppression of p53 and NF-kB pathway.