Effect of various selenium doses on chromium(IV)-induced nephrotoxicity in a male chicken model

Inflammatory Injury and Mitophagy in the Cock Heart Induced by the Oral Administration of Hexavalent Chromium

As a highly toxic heavy metal, chromium has caused a certain threat to public health and livestock breeding in recent years. In poultry, as one of our most commonly consumed meat product, its health issues will seriously threaten the safety of human life. As previous studies have confirmed, when cells are stimulated by the external environment, mitochondria, as an organelle that provides energy to the cells, can cause damage and autophagy. The purpose of this study is to confirm whether Cr(VI) can cause mitophagy in cock heart. We first randomly divided 32 cocks into four groups to explore the mechanism of this effect. The cocks were then separately exposed to four different dose levels, namely, the control level and 10, 30, and 50 mg/kg levels, via daily oral intake into the body through mixed feeding for 45 days. After 45 days, we sampled and detected pathological changes and the levels of inflammatory factors (IL-6, TNF-α, and IFN-γ), mitochondrial membrane potential (MMP), adenosine triphosphatases (ATPases), and mitophagy-related proteins (LC3, p62/SQTM1, TOMM20, and Parkin). We found that IL-6, TNF-α, IFN-γ, and LC3II contents increased with the increase in Cr(VI) concentration. However, MMP, ATPases, p62/SQTM1, and TOMM20 levels decreased with the increase in Cr(VI) concentration. At the same time, Cr(VI) exposure caused heart tissue damages and Parkin translocation. In conclusion, our results proved that inflammatory damage, mitochondrial function damage, and mitophagy in cock heart tissues were dependent on Cr(VI) concentration.

The antagonistic effect of selenium on lead-induced apoptosis and necroptosis via P38/JNK/ERK pathway in chicken kidney

Lead (Pb), as a toxic heavy metal pollutant, has been paid much attention. Pb is often discharged into the environment through the soot, wastewater and waste residue in industrial production, which poses a great threat to animal health. Selenium (Se) is a trace element known to antagonize the toxicity caused by heavy metals. However, the interaction between Se and Pb in chicken kidney and its specific biological mechanism are still unclear. So, we constructed chicken models of Pb exposure and Pb, Se co-exposure. Therefore, we used western blot and qRT-PCR to detect the expression of related genes. The results showed that Pb activated the MAPK signaling pathway by up-regulating the expression of MARK pathway genes to induce the expression of pro-apoptotic genes and necroptosis-related genes. Se can regulate the MARK signaling pathway and attenuated the expression of MAPK pathway genes altered by Pb to reduce apoptosis and necroptosis of chicken kidney cells. Our study gives new ideas for the specific mechanism of Pb nephrotoxicity and provides a reference for comparative medicine and clinical medication.

Environmental hexavalent chromium exposure induces gut microbial dysbiosis in chickens

Hexavalent chromium [Cr (VI)] is a hazardous heavy metal that pollutes soil, water and crops. Moreover, its prolonged exposure can harm the gastrointestinal system, liver and respiratory tract in different species, but knowledge regarding Cr (VI) influence on gut microbiota in chickens remains scarce. Therefore, this study was performed to investigate the impact of Cr (VI) on gut microbiota in chickens. Results revealed that the gut microbiota in Cr (VI)-induced chickens exhibited a distinct reduction in alpha diversity, accompanied by significant shifts in microbial composition. Specifically, Firmicutes and Bacteroidetes were the most dominant phyla in the control chickens, whereas Firmicutes and Actinobacteria were observed to be predominant in the Cr (VI)-induced populations. Moreover, the types and relative abundances of predominant bacterial genus in control and Cr (VI)-induced chickens were also different. Bacterial taxonomic analysis revealed that the relative abundances of 3 phyla and 7 genera obviously increased, whereas 8 phyla and 30 genera dramatically decreased during Cr (VI) induction. Among them, 1 phylum (Deferribacteres) and 5 genera (Butyricicoccus, Butyricimonas, Intestinimonas, Lachnospiraceae_FCS020_group and Ruminococcaceae_V9D2013_group) even could not be found in the gut microbial community of Cr (VI)-induced chickens. Taken together, our study indicated that the long-term exposure to Cr (VI) dramatically alter the gut microbial diversity and composition in chickens. Notably, it represents a breakthrough in understanding the impact of Cr (VI) on the intestinal microbiota of chickens.

Cr(VI) promotes tight joint and oxidative damage by activating the Nrf2/ROS/Notch1 axis

This study aimed to investigate whether Cr(VI) induced tight joint and oxidative damage in the small intestine, as mediated by the nuclear factor erythroid 2-related factor 2 (Nrf2)/reactive oxygen species (ROS)/Notch1 axis crosstalk. Thirty-two ICR mice were obtained and subjected to Cr(VI) via intragastric administration daily for 5 days. Western blot (WB) analysis, enzyme-linked immunosorbent assay (ELISA), immunohistochemistry (IHC) staining, and immunofluorescence (IF) staining were applied to detect small intestinal damage, Nrf2, Notch1, and respective downstream targets in this research. Results showed that Cr(VI) led to the tight joint and oxidative damage in the small intestine of mice. Nrf2 was stimulated, and Notch1 (Notch intracellular domain, NICD1) was activated to translocate into the nucleus and activate an antioxidant action. These findings were validated by WB analysis and IF staining. ROS levels increased as the Cr(VI) concentration increased. The colocalization analysis of Nrf2 and NICD1 implied that a crosstalk between Nrf2 and Notch1 existed. Therefore, this study indicated that the Nrf2/ROS/Notch1 axis crosstalk could aggravate the tight joint and oxidative damage in the small intestine after Cr(VI) treatment.

Mitophagy Induced by Mitochondrial Function Damage in Chicken Kidney Exposed to Cr(VI)

Cr(VI) is a heavy metal environmental pollutant and carcinogen. Excessive Cr(VI) exposure injures kidneys. This study aimed to investigate mitophagy induced by mitochondrial function damage in chicken kidney exposed to Cr(VI). To explore the mechanism involved, we randomly divided 40 one-day-old Hy-line Brown cockerels into four groups, with each group exposed to different concentrations of Cr(VI), i.e., 0, 10, 30 and 50 mg kg^-1, which were orally administered daily for 45 days. Excessive Cr(VI) increased tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and chemokine (C-X-C motif) ligand 1(CXCL1) expression and decreased Ca²⁺-adenosine triphosphatase (Ca²⁺-ATPase), Mg²⁺-ATPase and Na⁺/k⁺-ATPase activities in chicken kidney. Furthermore, Cr(VI) significantly increased reactive oxygen species (ROS) production and induced mitochondrial membrane potential (MMP) collapse and typical autophagosome formation. With the increase of Cr(VI) concentration, the Parkin translocation, value of LC3-II increased and decreased the content of p62/SQSTM1 and the translocase of outer mitochondrial membrane 20 (TOMM20). In summary, our findings explicated that mitochondrial function damage and mitophagy-related indicators were related to Cr(VI) concentration in chicken kidney.

The Effects of Selenium in Acrylamide-Induced Nephrotoxicity in Rats: Roles of Oxidative Stress, Inflammation, Apoptosis, and DNA Damage

We sought to determine the effects of selenium (Se) on acrylamide (ACR)-induced nephrotoxicity in rats. In our study, 50 adult male Sprague-Dawley rats weighing 200-250 g were randomly divided into five groups. The control group was given intra-gastric (i.g.) saline (1 mL) for 10 days. The ACR group was given i.g. ACR in saline (38.27 mg/kg titrated to 1 mL) for 10 days. The Se0.5 + ACR and Se1 + ACR groups were administered Se in saline (0.5 and 1 mg/kg, respectively) for 10 days and given i.g. ACR (38.27 mg/kg) one hour after the Se injections. The Se1 group was administered i.g. Se (1 mg/kg) for 10 days. On day 11, intracardiac blood samples were obtained from the rats while they were under anesthesia, after which they were euthanized by decapitation. Urea and creatinine concentrations of blood serum samples were analyzed with an autoanalyzer. Enzyme-linked immunosorbence immunosorbent assay (ELISA) was used to quantify malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), glutathione peroxidase (GPx), catalase (CAT), tumor necrosis factor-α (TNF-α), nuclear factor-κB (NF-κB), interleukin (IL)-33, IL-6, IL-1β, cyclooxygenase-2 (COX-2), kidney injury molecule-1 (KIM-1), mitogen-activated protein kinase-1 (MAPK-1), and caspase-3 in kidney tissues. Renal tissues were evaluated by histopathological and immunohistochemical examinations for 8-hydroxylo-2'-deoxyguanosin 8-hydroxy-2'-deoxyguanosine (8-OhDG) and Bax. Serum urea and creatinine levels were higher in the ACR group than in the control, and these ACR-induced increases were prevented by high doses of Se. Additionally, ACR induced the renal oxidative stress, inflammation, apoptosis, and damage to DNA and tissue; likewise, these were prevented by high doses of Se. Taken with ACR, Se confers protection against ACR-induced nephrotoxicity in rats by reducing oxidative stress, inflammation, apoptosis, and DNA damage.

Antagonistic effects of nano-selenium on broilers hepatic injury induced by Cr(VI) poisoning in AMPK pathway

Cr (chromium, with common valence states of III and VI) is one of the common broiler feed additives. Liver injury and metabolic disorders could be caused by Cr_(VI) (hexavalent chromium) poisoning in broilers. Oxidative damage and metabolic disorders of organisms caused by heavy metals could be antagonized by nano-Se (nano-selenium). Nano-Se was chosen to study the antagonism of Cr_(VI) poisoning in broilers. AMPK (Adenosine 5^,-monophosphate-activated protein kinase) is known as a "cell energy regulator" and plays a key regulatory role in carbohydrate and lipid metabolism. AMPK pathway and ACACA/CPT1A two genes were selected to study the prevention and treatment of nano-Se on Cr_(VI) poisoning in broilers and its molecular mechanism. For this purpose, 180 1-day-old AA (Arbor Acres) broilers were selected and randomly divided into 6 groups (n = 30) for further testing. After feeding as planned for 35 days, the livers of such broilers were taken for further examination including histopathological examination, differential gene expression analysis, and further validation on both mRNA and protein levels using related techniques like RT-qPCR, western blot, and immunohistochemistry (IHC). The histopathological examination suggested that the liver cells of the Cr_(VI) poisoning group were more severely injured than the nano-Se addition group. RT-qPCR results showed that the relative expression of ACACA gene in the Cr_(VI) poisoning group was significantly increased (P < 0.05), while the CPT1A gene's expression was significantly decreased (P < 0.01). Those results were reversed in the nano-Se addition group. Western blot results were consistent with RT-qPCR and both suggested antagonism of nano-Se on Cr_(VI). Through morphological and histopathological observation, as well as the measurement of the mRNA and protein expression levels of ACACA and CPT1A genes in AMPK pathway, it was confirmed that nano-Se has certain preventive and protective effects on Cr_(VI) poisoning in broiler chickens. Furthermore, the adverse effects of Cr_(VI) on carbohydrate and lipid metabolism in broilers can be antagonized by nano-Se through AMPK pathway. A new method and experimental basis were provided to the future study of Cr_(VI) poisoning in broilers.

Shinorine ameliorates chromium induced toxicity in zebrafish hepatocytes through the facultative activation of Nrf2-Keap1-ARE pathway

Hexavalent chromium, a heavy metal toxicant, abundantly found in the environment showed hepatotoxic potential in zebrafish liver and instigated the Nrf2-Keap1-ARE pathway as a cellular stress response as reported in our previous studies. In the present study we have evaluated the ameliorating effect of shinorine, a mycosporine like amino acid (MAAs) and a mammalian Keap1 antagonist against chromium induced stress in zebrafish hepatocytes. Shinorine was found to be effective in increasing the cell viability of chromium treated hepatocytes through curtailing the cellular ROS content. Trigonelline, an Nrf2 inhibitor was found to reduce the viability of hepatocyte cultures co-exposed to shinorine and chromium. In other words, trigonelline being an Nrf2 blocker neutralised the alleviating effect of shinorine. This indicated that shinorine mediated cyto-protection in Cr [VI]-intoxicated cells is Nrf2 dependent. Further, qRT-PCR analysis revealed comparatively higher expression of nfe2l2 and nqo1 in shinorine + chromium treated hepatocytes than cells exposed to chromium alone indicating a better functioning of Nrf2-Keap1-Nqo1 axis. To further confirm if shinorine can lead to disruption of Nrf2-Keap1 interaction in zebrafish hepatocytes and render cytoprotection to chromium exposure, our in silico analysis through molecular docking revealed that shinorine could bind to the active amino acid residues of the DGR domain, responsible for Nrf2-Keap1 interaction of all the three Keap1s evaluated. This is the first report about shinorine that ameliorates chromium induced toxicity through acting as an Nrf2-Keap1 interaction disruptor. We additionally carried out in-silico pharmacokinetic and ADMET studies to evaluate druglikeness of shinorine whose promising results indicated its potential to be developed as an ideal therapeutic candidate against toxicant induced pathological conditions.

Platycodon grandifloras polysaccharides inhibit mitophagy injury induced by Cr (VI) in DF-1 cells

This study aimed to investigate the role of Platycodon grandiflorus polysaccharide (PGPS) in chromium (VI)-induced autophagy in a chicken embryo fibroblast cell lines (DF-1 cells). DF-1 cells were exposed to Cr (VI), PGPS_t, and Cr (VI) + PGPS_t, and their effects on cell viability, reactive oxygen species (ROS), mitochondrial membrane potential (MMP), and autophagy-related proteins were examined. The results showed that the cell viability was reduced after Cr (VI) treatment, and 3-MA, CsA or PGPS_t suppressed this decrease. Cr (VI) treatment increased the ROS levels and decreased the MMP, thereby enhancing the expression of mitochondrial autophagy marker proteins (PINK1, Parkin, and LC3-II), inhibiting mitophagy autophagy protein TOMM20 expression, and promoting the degradation of autophagy-related marker p62. These changes led to exceeding mitochondrial autophagy and cell trauma and could be mitigated by PGPS_t. Overall, our research showed that Cr (VI) can induce exceeding mitochondrial autophagy in DF-1 cells, whereas PGPS_t can improve Cr (VI)-induced mitochondrial autophagy by inhibiting ROS and restoring MMP.

Inflammatory injury and mitophagy induced by Cr(VI) in chicken liver

Cr(VI) is a widely used chemical. Excessive Cr(VI) exposure not only causes inflammatory damage but also induces mitophagy. This study aimed to demonstrate the effect of Cr(VI) on inflammatory injury and mitophagy in chicken liver. A total of 120 Hyland Brown cockerels (1 day old) were randomly divided into four groups and orally treated with different Cr(VI) doses (10% median lethal dose, 6% median lethal dose, 2% median lethal dose, and 0% median lethal dose) daily for 45 days to explore the underlying mechanism. Results showed that excessive Cr(VI) increased tumor necrosis factor-α, interleukin-6, and heat shock protein but decreased interferon-γ expression and adenosine triphosphate content in chicken liver. Cr(VI) significantly increased reactive oxygen species production, induced mitochondrial membrane potential collapse, and promoted autophagosome formation. Cr(VI) treatment also caused an increase in LC3-II, stimulated Parkin translocation, and inhibited the expression of p62/SQSTM1 and translocase of outer mitochondrial membrane 20. Therefore, excessive Cr(VI) caused inflammatory damage and mitophagy in chicken liver.

Mitophagy is involved in chromium (VI)-induced mitochondria damage in DF-1 cells

Cr (VI), which is a common heavy metal pollutant with strong oxidizing property, exists widely in nature. Organisms can be exposed to Cr (VI) through various means. Cr (VI) causes mitochondrial dysfunction after being absorbed by cells. Whether Cr (VI) induces the selective autophagic degradation of mitochondria, which is a biological process called mitophagy, remains unclear. Mitophagy not only recycles intracellularly damaged mitochondria to compensate for nutrient deprivation but also is involved in mitochondria quality control. Thus, this study investigated whether Cr (VI) could induce mitophagy in DF-1 cells. Carbonyl cyanide m-chlorophenylhydrazone, which is a mitochondrial-uncoupling reagent that induces mitophagy, was used. DF-1 cells were incubated with different doses of Cr (VI) for varying durations. The autophagy-related proteins LC3-II and p62 levels decreased after 6 h of Cr (VI) treatment but recovered within 24 h. The mitochondrial membrane potential, which is an indicator of mitochondrial damage, was detected by flow cytometry. We found that different durations of Cr (VI) treatment induced mitochondrial mass decrease and depolarization. Furthermore, the expression of the protein translocase of outer mitochondrial membrane 20 (TOMM20), which is a mitochondrial outer membrane protein, was decreased significantly in the presence of Cr (VI). Our findings indicate that Cr (VI) may contribute to the mitochondrial morphology and function damage and may therefore lead to the autophagic clearance of mitochondria.

Se deficiency induces renal pathological changes by regulating selenoprotein expression, disrupting redox balance, and activating inflammation

Selenium (Se) is closely associated with kidney disease, and renal injury often occurs together with hyposelenemia. This study was designed to reveal the mechanism underlying renal injury induced by Se deficiency in pigs. Twenty-four castrated male Yorkshire pigs were divided into two groups fed either a Se-deficient diet (0.007 mg Se per kg) or a Se-adequate diet (0.3 mg Se per kg). Serum and kidney samples were collected at the 16th week of the trial, processed, and analyzed for serum biochemistry, Se concentration, kidney index markers, histology, selenoprotein mRNA expression, redox status, and inflammatory cytokines. Dietary Se deficiency induced kidney injury, decreased (P < 0.05) Se concentrations, and increased (P < 0.05) kidney index and serum blood urea nitrogen, creatinine, and carbon dioxide values. Histological analysis indicated that Se deficiency induced inflammatory lesions and renal tubular atrophy in the renal medulla. Se deficiency downregulated (P < 0.05) nine selenoprotein genes (GPX1, SELENOW, SELENOH, SELENOP, GPX3, TXNRD2, SELENOI, SELENON, and SELENOM) and upregulated (P < 0.05) SEPHS2 in the kidneys. Se deficiency decreased (P < 0.05) the activity of glutathione peroxidase, thioredoxin reductase, and catalase, as well as the hydroxyl radical inhibition capacity, and increased (P < 0.05) the content of malondialdehyde and nitric oxide. Se deficiency increased (P < 0.05) the expression of the transcription factors NF-κB and HIF-1α, and regulated inflammatory cytokines. Se deficiency increased (P < 0.05) the expression of IL-6, IL-8, IL-12, IL-17, and cyclooxygenase-2, and decreased (P < 0.05) the expression of IL-10, IL-13, and TGF-β. These results indicated that Se deficiency induces kidney injury through the regulation of selenoproteins, oxidative stress, and inflammation.

Metabonomic analysis of the hepatic injury suffer from hexavalent chromium poisoning in broilers

Chromium is used in daily life and has a wide range of functions. It plays an important role in protein synthesis and carbohydrate and lipid metabolism. Chromium is found in trivalent Cr(III) and hexavalent Cr(VI) form; Cr(III) is relatively stable and intimately participates with many phenomena of metabolisms. Whereas, Cr(VI) is toxic, which results in growth inhibition and leading to changes in components of antioxidant systems as well as secondary metabolites. However, the molecular mechanism that is involved in Cr (VI)-induced hepatotoxicity is still unclear. For this purpose, 40 chickens were randomly assigned into two groups: the normal group (feeding the basic diet and clear water), the chromium group (16%LD₅₀, 74.24 mg/kg/day K₂Cr₂O₇ ). The samples were subjected to pathological examination and UHPLC-QE-MS non-target metabolomics method for metabolomics analysis of broiler liver using principal component analysis (PCA) and partial least squares discriminant analysis (OPLS-DA). The central venous cells of the broiler liver in the chromium poisoning group showed turbidity and flaky necrosis, nuclear condensation, nuclear rupture, and even nuclear dissolution. The differential metabolite analysis between the chromium poisoning and the control group showed that 32 differential metabolites were upregulated and 15 were downregulated in positive ion mode. Whereas,17 differential metabolites were downregulated, and 35 were downregulated in negative ion mode (P ≤ 0.05). The potential marker substances are oleic acidamide, farnesylacetone, betaine, taurine, choline, and galactinol. Additionally, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways showed that the lipid metabolism, carbohydrate metabolism, nucleotide metabolism, amino acid metabolism, energy metabolism, membrane transport, digestive system, and nervous system were the most important metabolic pathways in the liver. This study provides a theoretical basis for the future understanding of the pathogenesis of chromium poisoning and a new insight of the subsequent molecular mechanism of chromium hepatotoxicity.

Ameliorative effects of Annona muricata Linn. (Annonaceae) against potassium dichromate-induced hypertension in vivo: involvement of Kim-1/p38 MAPK/Nrf2 signaling

Background Recently, the incidences of hypertension and environmental pollution have increased significantly. This study investigates the antihypertensive effect of Annona muricata extract against K2Cr2O7-induced hypertension. Methods Fifty rats were used for this study, which were divided into five groups of 10 rats each. Rats in Group A received normal saline, and those in Groups B, C, D, and E were treated with A. muricata extract alone at 250 mg/kg, K2Cr2O7 at 30 mg/kg, pretreated with the extract at 250 mg/kg, and pretreated with gallic acid at 60 mg/kg for 14 days, respectively, and thereafter administered with a single intraperitoneal injection of K2Cr2O7 at 30 mg/kg. Results Administration of K2Cr2O7 significantly increased systolic, diastolic, and mean arterial pressure and caused prolonged QT and QTc intervals. Further, pretreatment with the extract at 250 mg/kg and gallic acid at 60 mg/kg significantly reduced high blood pressure to near-normal values. K2Cr2O7 intoxication led to significant increases in serum advanced oxidative protein products, myeloperoxidase, and xanthine oxidase, while serum nitric oxide (NO) also reduced significantly. Immunohistochemistry of the renal kidney injury molecule (Kim-1) and p38 MAPK showed increased expressions following the administration of K2Cr2O7 together with the downregulation of nuclear factor erythroid 2-related factor 2 (Nrf2). Pretreatment with the extract at 250 mg/kg and gallic acid at 60 mg/kg also increased the expressions of Nrf2 and downregulated Kim-1 and p38. Conclusion Together, we found that pretreatment with the extract at 250 mg/kg and gallic acid at 60 mg/kg normalized the blood pressure, reduced the markers of oxidative stress, and improved the antioxidant defense system and serum NO bioavailability.

Selenium-Chromium(VI) Interaction Regulates the Contents and Correlations of Trace Elements in Chicken Brain and Serum

This study aims to investigate the contents of trace elements in the brain and serum of male chickens and the effect of selenium-chromium(VI) interaction. A chronic experimental model was established by supplementing 22.14 mg/kg K₂Cr₂O₇ with 0.00, 0.31, 0.63, 1.25, 2.50, and 5.00 mg/kg Na₂SeO₃ mg/kg B.W. to water for chicken daily. After 14, 28, and 42 days of exposure to the solution, the brain and serum of chickens from each group were collected to detect the levels of Ca, Cu, Mn, Fe, Zn, and Mg by inductively coupled plasma mass spectrometer (ICP-MS). Cr(VI) time-dependently accumulated in the brain and serum. The contents of Cr increased both in the brain and serum with prolonged exposure. Cr contents in the brain and serum decreased in all Se groups compared with those in only Cr-treated groups. Ca contents decreased with prolonged exposure and increasing Se dosage. The contents of Cu and Mn increased on the 28th day but decreased on the 42nd day in the brain and serum. Fe and Zn contents decreased in the serum under prolonged exposure and increased on the 28th day but decreased on the 42nd day in the brain. Cr exposure did not significantly affect Mg contents in the brain but slightly decreased those in the serum. Therefore, appropriate doses of Se affected Cr accumulation, leading to adjustments in the contents and correlations of trace elements.

A Summary of New Findings on the Biological Effects of Selenium in Selected Animal Species-A Critical Review

Selenium is an essential trace element important for many physiological processes, especially for the functions of immune and reproductive systems, metabolism of thyroid hormones, as well as antioxidant defense. Selenium deficiency is usually manifested by an increased incidence of retention of placenta, metritis, mastitis, aborts, lowering fertility and increased susceptibility to infections. In calves, lambs and kids, the selenium deficiency demonstrates by WMD (white muscle disease), in foals and donkey foals, it is associated with incidence of WMD and yellow fat disease, and in pigs it causes VESD (vitamin E/selenium deficiency) syndrome. The prevention of these health disorders can be achieved by an adequate selenium supplementation to the diet. The review summarizes the survey of knowledge on selenium, its biological significance in the organism, the impact of its deficiency in mammalian livestock (comparison of ruminants vs. non-ruminants, herbivore vs. omnivore) and possibilities of its peroral administration. The databases employed were as follows: Web of Science, PubMed, MEDLINE and Google Scholar.