Effects of anti-stress agents on the growth performance and immune function in broiler chickens with vaccination-induced stress.

The aim of this study was to evaluate the effects of anti-stress agents on the growth performance and immune function of broilers under immune stress conditions induced by vaccination. A total of 128, 1-day-old Arbor Acres broilers were randomly divided into four groups. Group normal control (NC) was the control group. Group vaccination control (VC), T 0.5%, and T 1% were the treatment groups, which were nasally vaccinated with two doses of the Newcastle disease virus (NDV) vaccine. The chicks in groups T 0.5% and T 1% were fed conventional diets containing 0.5% and 1% anti-stress agents. Thereafter, these broilers were slaughtered on 1, 7, 14, and 21 days post-vaccination. The results indicated that anti-stress agents could significantly reduce serum adrenocorticotropic hormone (ACTH) (P < 0.01) and cortisol (CORT) (P < 0.05) levels, and improve the growth performance (P < 0.05) and immune function of broilers (P < 0.05); However, the levels of malondialdehyde (MDA) (P < 0.05) were decreased, and the decreased total antioxidant capacity (T-AOC) (P < 0.01) levels mediated by vaccination were markedly improved. In addition, anti-stress agents could attenuate apoptosis in spleen lymphocytes (P < 0.01) by upregulating the ratio of Bcl-2 to BAX (P < 0.01) and downregulating the expression of caspase-3 and -9 (P < 0.01), which might be attributed to the inhibition of the enzymatic activities of caspase-3 and -9 (P < 0.05). In conclusion, anti-stress agents may improve growth performance and immune function in broilers under immune-stress conditions.RESEARCH HIGHLIGHTS Investigation of effects and mechanism of immune stress induced by vaccination.Beneficial effect of anti-stress agents on growth performance, immune function, oxidative stress, and regulation of lymphocyte apoptosis.Demonstration of the effects of apoptosis on immune function in the organism.

Inhibition of the NF-κB pathway and ERK-mediated mitochondrial apoptotic pathway takes part in the mitigative effect of betulinic acid on inflammation and oxidative stress in cyclophosphamide-triggered renal damage of mice.

Betulinic acid (BA), an occurring pentacyclic triterpenoid, has various biological activities, such as anti-inflammation and antioxidation. Previous studies found that BA attenuated cyclophosphamide (CYP)-induced intestinal mucosal damage by inhibiting intestinal mucosal barrier dysfunctions and cell apoptosis. However, the effects and regulation mechanisms of BA on CYP-induced renal damage has not been reported in literature. Here, we found that BA pretreatment alleviated the elevation of serum urea level and inhibited the increase in serum neutrophil gelatinase-associated lipocalin level induced by CYP. Meanwhile, BA ameliorated renal tubular epithelial cell edema, and vacuolization of renal cortical tubular and renal glomerulus. Moreover, pretreatment with BA inhibited the mRNA expressions of pro-inflammatory cytokines interleukin-1ß (IL-1ß), IL-6, and tumor necrosis factor-α, and increased mRNA expressions of anti-inflammatory cytokines such as IL-10 and transforming growth factor-ß by inactivation nuclear factor kappa-B. Simultaneously, BA decreased the accumulation of reactive oxygen species and malondialdehyde, and lowered the levels of superoxide dismutase and glutathione, while increased the activity of glutathione peroxidase in CYP-induced kidney damage mice. Besides, BA reduced the phosphorylation of extracellular signal-regulated kinases (ERK), inhibited the ratio of Bcl-2/Bax and cell apoptosis in CYP-triggered kidney damage. Furthermore, BA and/or PD98059 (an inhibitor of ERK) regulated mitigation of CYP-elicited renal injury and deactivation of the ERK pathway and mitochondrial apoptotic pathway, indicating that the protective effect of BA on CYP-induced renal damage may be associated with the down-regulation of ERK-mediated mitochondrial apoptotic pathway. Thus, BA could be a candidate agent against chemotherapy drug-induced nephrotoxicity by reducing inflammation and oxidative stress through suppression of ERK-mediated mitochondrial apoptotic pathway.

Ameliorative effect of betulinic acid against zearalenone exposure triggers testicular dysfunction and oxidative stress in mice via p38/ERK MAPK inhibition and Nrf2-mediated antioxidant defense activation.

Zearalenone (ZEA) is a nonsteroidal estrogenic mycotoxin, which mainly contaminates grains and has estrogen-like effects on the reproductive system. Betulinic acid (BA), a natural lupane-type pentacyclic triterpene, has anti-oxidative and anti-inflammatory properties. This study aimed to investigate whether BA alleviates ZEA-induced testicular damage and explore the possible mechanism. Here, BA ameliorated testicular damage by mitigating the disordered arrangement of seminiferous tubules, the exfoliation of lumen cells, and the increase of cell apoptosis caused by ZEA. Meanwhile, BA alleviated ZEA-triggered testicular damage by restoring hormone levels and sperm motility, and reconstructing the blood-testis-barrier. Moreover, BA alleviated ZEA-exposed testicular oxidative stress by activating Nrf2 pathway. Furthermore, BA moderated ZEA-evoked testicular inflammation by inhibiting p38/ERK MAPK pathway. Overall, our results revealed that BA has a therapeutic protective effect on ZEA-induced testicular injury and oxidative stress via p38/ERK MAPK inhibition and Nrf2-mediated antioxidant defense activation, which provides a viable alternative to alleviate ZEA-induced male reproductive toxicology.

The role of ER stress and ATP/AMPK in oxidative stress meditated hepatotoxicity induced by citrinin.

Citrinin, a secondary metabolite, can pose serious risks to the environment and organisms, but its hepatotoxic mechanisms are still unclear. Histopathological and ultrastructural results showed that citrinin-induced liver injury in Kunming mice, and the mechanism of citrinin-induced hepatotoxicity was studied in L02 cells. Firstly, citrinin mades L02 cell cycle arrest in G2/M phase by inhibition of cyclin B1, cyclin D1, cyclin-dependent kinases 2 (CDK2), and CDK4 expression. Secondly, citrinin inhibits proliferation and promotes apoptosis of L02 cells via disruption of mitochondria membrane potential, increase Bax/Bcl-2 ration, activation of caspase-3, 9, and enhance lactate dehydrogenase (LDH) release. Then, citrinin inhibits superoxide dismutase (SOD) activity and increases the accumulation of malondialdehyde (MDA) and reactive oxygen species (ROS), resulting oxidative damage in L02 cells; upregulates the protein expression of binding immunoglobulin protein (Bip), C/EBP homologous protein (CHOP), PKR-like ER kinase (PERK) and activating transcription factor6 (ATF6), inducing ER stress in L02 cells; increases the phosphorylation of AMP-activated protein kinase (AMPK) and decreases the content of adenosine-triphosphate (ATP), activating AMPK pathway in L02 cells. Eventually, pretreatment with NAC, an ROS inhibitor, alleviates citrinin-induced cell cycle G2/M arrest and apoptosis by inhibiting ROS-mediated ER stress; pretreatment with 4-PBA, an ER stress inhibitor, reversed ER stress and p-AMPK; pretreatment with dorsomorphin, an AMPK inhibitor, decreases citrinin-induced cell cycle G2/M arrest and apoptosis. In summary, citrinin induces cell cycle arrest and apoptosis to aggravate liver injury by activating ROS-ER stress-AMPK signaling pathway.

Involvement of endoplasmic reticulum stress-activated PERK-eIF2α-ATF4 signaling pathway in T-2 toxin-induced apoptosis of porcine renal epithelial cells.

T-2 toxin is a highly toxic trichothecene that can induce toxic effects in a variety of organs and tissues, but the pathogenesis of its nephrotoxicity has not been elucidated. In this study, we assessed the involvement of protein kinase RNA-like ER kinase (PERK)-mediated endoplasmic reticulum (ER) stress and apoptosis in PK-15 cells cultured at different concentrations of T-2 toxin. Cell viability, antioxidant capacity, intracellular calcium (Ca2+) content, apoptotic rate, levels of ER stress, and apoptosis-related proteins were studied. T-2 toxin inhibited cell proliferation; increased the apoptosis rate; and was accompanied by increased cleaved caspase-3 expression, altered intracellular oxidative stress marker levels, and intracellular Ca2+ overloading. The ER stress inhibitor 4-phenylbutyrate (4-PBA) and PERK selective inhibitor GSK2606414 prevented the decrease of cell activity and apoptosis caused by T-2 toxin. The altered expression of glucose regulatory protein 78 (GRP78), C/EBP homologous protein (CHOP), and caspase-12 proved that ER stress was involved in cell injury triggered by T-2 toxin. T-2 toxin activated the phosphorylation of PERK and the alpha subunit of eukaryotic initiation factor 2 (eIF2α) and upregulated the activating transcription factor 4 (ATF4), thereby triggering ER stress via the GRP78/PERK/CHOP signaling pathway. This study provides a new perspective for understanding the nephrotoxicity of T-2 toxin.

Betulinic acid attenuates cyclophosphamide-induced intestinal mucosa injury by inhibiting the NF-κB/MAPK signalling pathways and activating the Nrf2 signalling pathway.

Betulinic acid (BA), a pentacyclic triterpenoid, has been associated with several biological effects, such as antioxidant, anti-inflammatory and antiviral activities. Previous studies have demonstrated that BA has the ability to alleviate intestinal mucosal damage, however, the potential mechanism associated with the effect has not been reported. This study aimed to investigate the possible protective mechanism of BA against cyclophosphamide (CYP)-induced intestinal mucosal damage. Here, we found that BA pretreatment prevented intestinal mucosal barrier dysfuction from CYP-challenged mice by repairing the intestinal physical, chemical, and immune barriers. Moreover, BA treatment suppressed the CYP-induced oxidative stress by activating the nuclear factor erythroid 2 [NF-E2]-related factor (Nrf2) pathway blocked reactive oxygen species (ROS) accumulation. In addition, BA inhibited CYP-triggered intestinal inflammation through down-regulating the nuclear transcription factor kappa B (NF-κB)/mitogen-activating protein kinase (MAPK) pathways. Furthermore, BA pretreatment reduced intestinal apoptosis by blocking ROS-activated mitochondrial apoptotic pathway. Overall, the current study demonstrated the protective effect of BA against CYP-caused intestinal mucosal damage by regulating the Nrf2 and NF-κB/MAPK signalling pathways, which may provide new therapeutic targets to attenuate intestinal impairment and maintain intestinal health.

Benzyl Isothiocyanate, a Vegetable-Derived Compound, Induces Apoptosis via ROS Accumulation and DNA Damage in Canine Lymphoma and Leukemia Cells.

Treatment of neoplastic diseases in companion animals is one of the most important problems of modern veterinary medicine. Given the growing interest in substances of natural origin as potential anti-cancer drugs, our goal was to examine the effectiveness of benzyl isothiocyanate (BITC), a compound found in cruciferous vegetables, against canine lymphoma and leukemia. These are the one of the most common canine cancer types, and chemotherapy is the only treatment option. The study involved established cell lines originating from various hematopoietic malignancies: CLBL-1, GL-1, CLB70 and CNK-89, immortalized noncancerous cell lines: MDCK and NIH-3T3 and canine peripheral blood mononuclear cells (PBMCs). The cytotoxic activity of BITC, apoptosis induction, caspase activity and ROS generation were evaluated by flow cytometry. H2AX phosphorylation was assessed by western blot. The study showed that the compound was especially active against B lymphocyte-derived malignant cells. Their death resulted from caspase-dependent apoptosis. BITC induced ROS accumulation, and glutathione precursor N-acetyl-l-cysteine reversed the effect of the compound, thus proving the role of oxidative stress in BITC activity. In addition, exposure to the compound induced DNA damage in the tested cells. This is the first study that provides information on the activity of BITC in canine hematopoietic malignancies and suggests that the compound may be particularly useful in B-cell neoplasms treatment.

The reproductive stress hypothesis.

In this paper, we propose the reproductive stress hypothesis that describes the pregnant females response to reproductive events based upon the activation of the hypothalamic-pituitary-adrenal axis and sympathetic adrenomedullary system. The main components of the reproductive stress hypothesis can be summarized as follows: (1) events unique to reproduction including empathema, pregnancy, parturition and lactation cause non-specific responses in females, called active reproductive stress; (2) the fetus is a special stressor for pregnant females where endocrine hormones, including corticotropin-releasing hormones and fetal glucocorticoids secreted by the fetus and placenta, enter the maternal circulatory system, leading to another stress response referred to as passive reproductive stress and (3) response to uterine tension and intrauterine infection is the third type of stress, called fetal intrauterine stress. Appropriate reproductive stress is a crucial prerequisite in normal reproductive processes. By contrast, excessive or inappropriate reproductive stress may result in dysfunctions of the reproductive system, such as compromised immune function, leading to susceptibility to disease. The novel insights of the reproductive stress hypothesis have important implications for deciphering the pathogenesis of certain diseases in pregnant animals, including humans, which in turn may be applied to preventing and treating their occurrence.

Ganoderma lucidum Polysaccharides Prevent Palmitic Acid-Evoked Apoptosis and Autophagy in Intestinal Porcine Epithelial Cell Line via Restoration of Mitochondrial Function and Regulation of MAPK and AMPK/Akt/mTOR Signaling Pathway.

Ganoderma lucidum polysaccharide (GLP) extracted from Ganoderma lucidum (Leyss. ex Fr.) Karst, a traditional Chinese medicine, is a biologically active substance reported to possess anti-oxidative, anti-apoptotic, and neurological protection. However, it is unknown whether GLP have any protective effect against high-fat constituents-induced epithelial cell injury. The aim of this study was to investigate the protection and molecular mechanism of GLP on injury induced by palmitic acid (PA) in the intestinal porcine epithelial cell line (IPEC-J2). First, we tested whether the treatment of GLP attenuate PA-induced IPEC-J2 cell death. GLP markedly blocked PA-caused cytotoxicity and apoptosis in IPEC-J2 cells. Moreover, GLP recovered the decreased mitochondrial function and inhibited activation of caspase-dependent apoptotic pathway. Interestingly, PA promoted cell apoptosis and autophagy through stimulation of phosphorylation of mitogen-activated protein kinases (MAPKs), AMP-activated protein kinase (AMPK), and inhibition of phosphorylation of Akt and mammalian target of rapamycin (mTOR), which was reversed by GLP. Taken together, this study revealed a protective effect of GLP against PA-evoked IPEC-J2 cell death through anti-apoptotic and anti-autophagic properties.

Protective Effect of Koumine, an Alkaloid from Gelsemium Sempervirens, on Injury Induced by H2O2 in IPEC-J2 Cells.

Medicinal herbal plants have been commonly used for intervention in different diseases and improvement of health worldwide. Koumine, an alkaloid monomer found abundantly in Gelsemium plants, can be effectively used as an antioxidant. The purpose of this study was to evaluate the potential protective effect of koumine against hydrogen peroxide (H2O2)-induced oxidative stress and apoptosis in porcine intestinal epithelial cell line (IPEC-J2 cells). MTT assays showed that koumine significantly increased cell viability in H2O2-mediated IPEC-J2 cells. Preincubation with koumine ameliorated H2O2-medicated apoptosis by decreasing reactive oxygen species (ROS) production, and efficiently suppressed the lactate dehydrogenase (LDH) release and malondialdehyde (MDA) production. Moreover, a loss of superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) activities was restored to normal level in H2O2-induced IPEC-J2 cells upon koumine exposure. Furthermore, pretreatment with koumine suppressed H2O2-mediated loss of mitochondrial membrane potential, caspase-9 and caspase-3 activation, decrease of Bcl-2 expression and elevation of Bax expressions. Collectively, the results of this study indicated that koumine possesses the cytoprotective effects in IPEC-J2 cells during exposure to H2O2 by suppressing production of ROS, inhibiting the caspase-3 activity and influencing the expression of Bax and Bcl-2. Koumine could potentially serve as a protective effect against H2O2-induced apoptosis.

T-2 Toxin Exposure Induces Apoptosis in TM3 Cells by Inhibiting Mammalian Target of Rapamycin/Serine/Threonine Protein Kinase(mTORC2/AKT) to Promote Ca2+Production.

Although mTOR (the mammalian target of rapamycin) can regulate intracellular free Ca2+concentration in normal cultured podocytes, it remains elusive as to how mTORC2/AKT-mediated Ca2+participates in the process of T-2 toxin-induced apoptosis. The potential signaling responsible for intracellular Ca2+ concentration changes was investigated using immunoblot assays in an in vitro model of TM3 cell injury induced by T-2 toxin. Changes in Ca2+ were assessed using the Ca2+-sensitive fluorescent indictor dye Fura 2-AM. The cytotoxicity of TM3 cells was assessed with an MTT bioassay, and apoptosis was measured using Annexin V-FITC staining. Following T-2 toxin treatment, the growth of cells, phospho-mTORSer2481, phospho-mTORSer2448, and phospho-AktSer473 were significantly decreased in a time-dependent manner, whereas Ca2+ and apoptosis were increased. T-2 toxin-induced apoptosis was prevented by BAPTA-AM (a Ca2+chelator) and MHY1485 (an mTOR activator), and the application of mTOR activator MHY1485 also prevented the increase of intracellular free Ca2+concentration in TM3 cells. Our results strongly suggest that T-2 toxin exposure induces apoptosis in TM3 cells by inhibiting mTORC2/AKT to promote Ca2+ production.

A Potential Mechanism for the Anti-Apoptotic Property of Koumine Involving Mitochondrial Pathway in LPS-Mediated RAW 264.7 Macrophages.

Koumine is a kind of alkaloid extracted from Gelsemium elegans (G. elegans). Benth, which has shown promise as an anti-tumor, anxiolytic, and analgesic agent. In our present study, the effect of koumine on lipopolysaccharide (LPS)-mediated RAW 264.7 cell apoptosis was evaluated. MTT assays showed that koumine obviously increased cell viability in LPS-mediated RAW 264.7 macrophages. Preincubation with koumine ameliorated LPS-medicated apoptosis by decreasing reactive oxygen species (ROS) production, which resulted in a significant decrease in the levels of nitric oxide (NO) and inducible nitric oxide synthase (iNOS). In addition, koumine-pretreated RAW 264.7 macrophages exhibited reduction of LPS-induced levels of TNF-α, IL-1ß, and IL-6 mRNA. Furthermore, pretreatment with koumine suppressed LPS-mediated p53 activation, loss of mitochondrial membrane potential, caspase-3 activation, decrease of Bcl-2 expression, and elevation of Bax and caspase-3 expressions, suggesting that koumine might act directly on RAW 264.7 cells to inhibit LPS-induced apoptosis. It seems as though the mechanism that koumine possesses is the anti-apoptotic effect mediated by suppressing production of ROS, activation of p53, and mitochondrial apoptotic pathways in RAW 264 cells. Koumine could potentially serve as a protective effect against LPS-induced apoptosis.

Arsanilic acid causes apoptosis and oxidative stress in rat kidney epithelial cells (NRK-52e cells) by the activation of the caspase-9 and -3 signaling pathway.

Arsenic exists widely in rock, water and air, and arsanilic acid (also known as aminophenyl arsenic acid) is an organoarsenic compound and has been used as feed additives. Organoarsenic compounds in foodstuff cause adverse effects, including acute and chronic toxicity, in animals and humans. However, little is known about the cellular toxicity and mechanisms of organic arsenic on the kidney. In this study, we explored the toxicity and molecular mechanisms of arsanilic acid on rat kidney epithelial cells (NRK-52e cells). The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay showed that arsanilic acid inhibited the proliferation of rat NRK-52e cells in a dose-dependent manner, and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay and flow cytometry revealed that arsanilic acid induced cellular apoptosis in NRK-52e cells. Fluorescence spectrophotometer displayed that arsanilic acid caused a loss of mitochondrial transmembrane potential (MMP) of NRK-52e cells, but enhanced reactive oxygen species level of these cells. Notably, trolox, a water-soluble derivative of vitamin E, protected NRK-52e cells against MMP loss and apoptosis caused by arsanilic acid. Western blots with caspase inhibitors further indicated that arsanilic acid increased expression of active caspase-3 and -9 in NRK-52e cells. Collectively, these results suggest that arsanilic acid causes apoptosis and oxidative stress in rat kidney epithelial cells through activation of the caspase-9 and -3 signaling pathway. This study thus provides a novel insight into molecular mechanisms by which arsanilic acid has adverse cytotoxicity on renal tubular epithelial cells.

Betulinic acid attenuates T-2 toxin-induced lung injury by activating Nrf2 signaling pathway and inhibiting MAPK/NF-κB signaling pathway.

T-2 toxin, a type-A trichothecene mycotoxin, exists ubiquitously in mildewed foods and feeds. Betulinic acid (BA), a pentacyclic triterpenoid derived from plants, has the effect of relieving inflammation and oxidative stress. The purpose of this study was to investigate whether BA mitigates lung impairment caused by T-2 toxin and elucidate the underlying mechanism. The results indicated that T-2 toxin triggered the inflammatory cell infiltration, morphological alterations and cell apoptosis in the lungs. It is gratifying that BA ameliorated T-2 toxin-caused lung injury. The protein expression of nuclear factor erythrocyte 2-related factor 2 (Nrf2) pathway and the markers of antioxidative capability were improved in T-2 toxin induced lung injury by BA mediated protection. Simultaneously, BA supplementation could suppress T-2 toxin-induced mitogen-activated protein kinase (MAPK)/nuclear factor-kappa B (NF-κB)-dependent inflammatory response and mitochondrial apoptotic pathway. Therefore, T-2 toxin gave rise to pulmonary toxicity, but these changes were moderated by BA administration through regulation of the Nrf2/MAPK/NF-κB pathway, which maybe offer a viable alternative for mitigating the lung impairments caused by the mycotoxin.

Betulinic acid mitigates zearalenone-induced liver injury by ERS/MAPK/Nrf2 signaling pathways in mice.

Zearalenone (ZEA) is a mycotoxin commonly found in cereals and feedstuffs, which can induce oxidative stress and inflammation to cause liver damage in humans and animals. Betulinic acid (BA) is extracted from pentacyclic triterpenoids of many natural plants and has anti-inflammatory, and anti-oxidation biological activities in many studies. However, the protective effect of BA on liver injury induced by ZEA has not been reported. Therefore, this study aims to explore the protective effect of BA on ZEA-induced liver injury and its possible mechanism. In the mice experiment, ZEA exposure increased the liver index and caused histopathological impairment, oxidative damage, hepatic inflammatory responses, and increased hepatocyte apoptosis. However, when combined with BA, it could inhibit the production of ROS, up-regulate the proteins expression of Nrf2 and HO-1 and down-regulate the expression of Keap1, and alleviate oxidative damage and inflammation in the liver of mice. In addition, BA could alleviate ZEA-induced apoptosis and liver injury in mice by inhibiting the endoplasmic reticulum stress (ERS) and MAPK signaling pathways. In conclusion, this study revealed the protective effect of BA on the hepatotoxicity of ZEA for the first time, providing a new perspective for the development of ZEA antidote and the application of BA.

Citrinin Exposure Induced Testicular Damage and Spermatogenesis Disorder by Triggering Endoplasmic Reticulum Stress.

Damage to the reproductive system is the key factor leading to male infertility. Citrinin (CTN) is produced by Penicillium and Aspergillus in nature, and is definitely found in food and animal feed. Studies have revealed that CTN can cause damage to male reproductive organs and reduce fertility, but the mechanism of toxicity has not been revealed. In the present study, male Kunming mice were given different doses of CTN (0, 1.25, 5 or 20 mg/kg BW) by intragastric administration. The results demonstrated that CTN exposure caused disorder of androgen, a decline in sperm quality, and histopathological damage of testis. The inhibition of the expression of ZO-1, claudin-1 and occludin suggests that the blood-testis barrier (BTB) was damaged. Simultaneously, CTN inhibited the activity of antioxidant enzymes such as CAT and SOD, and promoted the production of MDA and ROS, resulting in oxidative damage of testis. Additionally, apoptotic cells were detected and the ratio of Bax/Bcl-2 was increased. Not only that, CTN activated the expression of endoplasmic reticulum stress (ERS)-related proteins IRE1, ATF6, CHOP, and GRP78. Interestingly, 4-Phenylbutyric Acid (4-PBA, an ERS inhibitor) treatment blocked the adverse effects of CTN exposure on male reproduction. In short, the findings suggested that CTN exposure can cause damage to mouse testis tissue, in which ERS exhibited an important regulatory role.

Tannic Acid Ameliorates Systemic Glucose and Lipid Metabolic Impairment Induced by Low-Dose T-2 Toxin Exposure.

Subacute mycotoxin exposure in food is commonly overlooked. As one of the most toxic trichothecene mycotoxins, the T-2 toxin severely pollutes human foods and animal feeds. In our study, we investigated the effects of low-dose T-2 toxin on glucose and lipid metabolic function and further investigated the protective effect of tannic acid (TA) in C57BL/6J mice. Results showed that low-dose T-2 toxin significantly impaired blood glucose and lipid homeostasis, promoted ferroptosis in the pancreas and subsequent repression of insulin secretion in ß-cells, and impacted hepatic glucose and lipid metabolism by targeted inhibition of the insulin receptor substrate (IRS)/phosphatidylin-ositol-3-kinase (PI3K)/protein kinase B (AKT) signaling pathway, which induced insulin resistance and steatosis in the liver. TA treatment attenuated pancreatic function and hepatic metabolism by ameliorating oxidative stress and insulin resistance in mice. These findings provide new perspectives on the toxic mechanism and intervention of chronic subacute toxicity of foodborne mycotoxins.

Betulinic acid alleviates zearalenone-induced uterine injury in mice.

Zearalenone (ZEA) is a mycotoxin with estrogen-like biological activity, which widely present in feed and raw materials, with strong reproductive system toxicity and a major threat to animal reproduction. Betulinic acid (BA) is a natural plant compound with antioxidant, anti-inflammatory and other pharmacological activities. However, the mechanism of ZEA-induced uterine injury and the protective effect of BA have not been reported. Our results show that ZEA could cause uterine histopathological damage and cellular ultrastructural damage, affecting the secretion of sex hormones, such as estradiol (E2) and progesterone (P4), and increase the mRNA and protein expression of estrogen receptor α (ERα). ZEA could inhibit the activities of catalase (CAT) and superoxide dismutase (SOD), increase the production of malondialdehyde (MDA) and reactive oxygen species (ROS), and cause uterine oxidative stress. Furthermore, ZEA affected the homeostasis of uterine cell proliferation and death by regulating the expression of proliferating cell nuclear antigen (PCNA) and activating the mitochondrial apoptotic pathway. ZEA-induced uterine injury might be related to the activation of p38/ERK MAPK signaling pathway. However, the regulatory effect of ZEA on the uterus was reversed after BA treatment. In conclusion, the uterus is an important target organ attacked by ZEA, and BA showed a good therapeutic effect.

Suppression of endoplasmic reticulum stress-associated pathways and hepatocyte apoptosis participates in the attenuation of betulinic acid on alcohol-provoked liver injury in mice.

Endoplasmic reticulum stress (ERS) plays a vital role in the pathogenesis of the alcoholic liver disease (ALD). Betulinic acid (BA) has been reported to be effective in the attenuation of ALD; however, its role in ERS and associated stress-signaling pathways remains elusive. Here, we found that the BA pretreatment significantly reduced the alcohol-induced liver injury by decreasing the activities of serum alanine aminotransferase and aspartate aminotransferase, alleviating fat deposition and rupturing the ER in hepatocytes. Moreover, the protective effect of BA on ALD was associated with the inhibition of reactive oxygen species accumulation and ERS, accompanied by the downregulation of glucose-regulated protein 78 (Grp78), Grp94, phosphorylation-inositol-requiring enzyme 1α (p-IRE1α), and phosphorylation-protein kinase R-like endoplasmic reticulum kinase (p-PERK), activating the transcription factor 6 (ATF6) and C/EBP homologous protein (CHOP). Moreover, the alcohol-induced hepatocyte apoptosis was reduced, along with the downregulation of the mitogen-activated protein kinase pathway, caspase-12, caspase-3, and caspase-7, following BA administration. Additionally, the BA-mediated mitigation of alcohol-induced liver injury and deactivation of the ER pathways were the same with 4-PBA, an inhibitor of ERS, indicating that the protective effect of BA on ALD may be regulated by ERS-associated pathways. Collectively, BA is a potentially desirable agent for the ALD, which may reduce hepatocyte apoptosis by suppressing excessive ERS in the liver.

Betulinic acid attenuates cognitive dysfunction, oxidative stress, and inflammation in a model of T-2 toxin-induced brain damage.

T-2 toxin is a mycotoxin that has harmful effects on the immune system and cognitive function. Betulinic acid (BA) is a plant-derived pentacyclic lupane-type triterpenoid which possesses a wide spectrum of bioactivities. The study was aimed to explore whether BA has a protective effect on cognitive impairment and oxidative stress caused by T-2 toxin. BA was suspended in 1% soluble starch by continuous intragastric administration for 14 days, then the brain damage in mice was induced by a single intraperitoneal injection of T-2 toxin (4 mg/kg). It was found that BA alleviated the reduction of discrimination index in T-2 toxin-treated mice, and enhanced dopamine (DA), 5-hydroxytryptamine (5-HT), and acetylcholine (ACH) levels of brain neurotransmitter. Meanwhile, BA pretreatment ameliorated oxidative stress through increase of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and glutathione (GSH) levels, and inhibition of the generation of reactive oxygen species (ROS) and malondialdehyde (MDA) in the brain of mice exposed to T-2 toxin. Moreover, BA reduced brain hemorrhage and ecchymosis, improved the mitochondrial morphology, enriched the number of organelles, and inhibited cell apoptosis in brain challenged with T-2 toxin. Furthermore, BA inhibited mRNA expression of pro-inflammatory cytokines such as interleukin-1ß (IL-1ß), IL-6, and tumor necrosis factor-α (TNF-α) as well as enhanced mRNA expression of anti-inflammatory cytokine such as IL-10 in the brain of T-2 toxin-triggered mice. Therefore, BA could improve the cognitive function, enhance the antioxidant capacity, and inhibit the secretion of proinflammatory cytokines in brain, thereby playing a preventive and protective role against brain damage caused by T-2 toxin.