Sb Treatment Research Articles

Antimony exposure affects oocyte quality and early embryo development via excessive mitochondrial oxidation and dysfunction

Antimony (Sb) is a metalloid, widely presents in the environment and associates with human health. In this study, we aimed to decipher whether Sb exposure is harmful to female reproduction and explore the underlying mechanisms. The ICR mice were exposed to 0, 5, 10, and 20 mg/kg acetate potassium Sb tartrate trihydrate by intraperitoneal injection for 10 days, then mouse oocytes were collected for further analysis. We first found a significant decrease in the proportion of MII-stage oocytes obtained from supernumerary ovulation in the fallopian tubes and early embryo development under Sb treatment. Then a series of tests showed Sb affects oocyte maturation by damaging the cytoskeleton of microtubule and actin. Moreover, the abnormal distribution of cortical granules and their component Ovastacin in oocytes, combined with reduced expression levels of Juno, affected sperm-oocyte binding and led to fertilization failure. Based on the sequencing results and experimental validation, it was demonstrated that Sb exposure impairs mitochondrial distribution and membrane potential, elevated levels of mitochondrial superoxide, finally caused energy supply deficits. Mitochondrial damage in oocytes after Sb exposure results in the excessive oxidative stress and early apoptosis. Taken together, these data suggest that Sb exposure decreases oocyte quality and female fertilization ability by impairing mitochondrial function and redox perturbation.

Endocrine system, cell growth and death, and energy metabolism induced by Sb(III) exposure in earthworm (Pheretima guillemi) revealed by transcriptome and metabolome analysis

Antimony (Sb) is known for its severe and extensive toxicity, and earthworms are considered important indicator organisms in soil ecosystems. Therefore, the present study investigated the mechanism of toxicity of the Sb at different concentrations (50, 200 mg/kg) on earthworms using biochemical indicators, pathological sections, as well as metabolomics and transcriptomics analyses. The results showed that as the exposure concentration increased, both the antioxidant system of earthworms, extent of intestinal damage, and their metabolomic characteristics were significantly enhanced. In the 50 and 200 mg/kg Sb treatment group, 30 and 177 significant differentially changed metabolites (DCMs) were identified, respectively, with the most DCMs being down- and up-regulated, respectively. Metabolomics analysis showed that the contents of dl-tryptophan, glutamic acid, glycine, isoleucine, l-methionine, involved in the protein digestion and absorption as well as aminoacyl-tRNA biosynthesis were significantly up-regulated under the 200 mg/kg treatment. At the transcriptional level, Sb mainly affected the immune system, nervous system, amino acid metabolism, endocrine system, and carbohydrate metabolism in earthworms. The integration of transcriptomic and metabolomic data indicated that high doses of Sb regulated the metabolites and genes related to the oxidative phosphorylation pathway in earthworms. Overall, these results revealed global responses beyond the scope of conventional toxicity endpoints and facilitated a more in-depth and comprehensive assessment of the toxic effects of Sb.

Adsorptive Removal of Sb(V) from Wastewater by Pseudo-Boehmite: Performance and Mechanism

With the increasing concern about antimony (Sb) pollution and remediation in aquatic ecosystems, more and more feasible technologies have been developed. Adsorption has been extensively studied due to the simplicity of its operation and its minimal environmental effects, but the lack of cheap and stable adsorbents has limited its application in Sb treatment. In this study, pseudo-boehmite (PB) was successfully synthesized via aluminum isopropylate hydrolysis, and its potential for removing Sb(V) from wastewater was explored. The removal efficiency of Sb(V) was 92.50%, and the maximum adsorption capacity was 75.25 mg/g under optimal conditions (pH 5.0, 2 g·L−1 PB, and 10 mg·L−1 Sb(V)). In addition, better performance could be obtained at acidic conditions (pH 3.0–5.0). Surface complexation, electrostatic attraction, and hydrogen bonding were identified as potential major processes for Sb(V) elimination by PB based on experimental and characterization data. This study presents a promising approach for the efficient removal of Sb(V) from wastewater, offering a new insight into the application of aluminum-based materials for heavy metal removal.

Gel-Embedded Biochar and Hydroxyapatite Composite for the Improvement of Saline-Alkali Soil and Plant Growth Promotion.

Soil amendments play a crucial role in modern agriculture, as they effectively enhance the planting environment. This study innovatively proposes the use of gel as a crosslinking agent to embed biochar and hydroxyapatite (HAP), thereby preparing a novel soil amendment. Furthermore, this study investigates the soil improvement effects of this amendment as well as its influence on plant growth. This study employed a hydrothermal method to combine corn stalk (CB) or sludge (SB) biochar with HAP at different ratios (0-20%). Subsequently, sodium alginate gel (SA) was utilized to encapsulate the biochar and minerals, successfully forming a ternary composite gel material (corn stalk biochar/sludge biochar-sodium alginate gel-hydroxyapatite: CB/SB-SA-HAP). Finally, the practical effectiveness of this amendment was verified through potted soil experiments. The results indicate that the CB/SB-SA-HAP composite materials exhibited a micrometre-scale spherical structure with well-developed micropores and possess the functional groups of CB/SB, SA, and HAP, along with unique mineral properties. Through pot experiments, it was verified that the composite material effectively enhances multiple soil properties. After 21 days of cultivation, the soil pH values stabilized within the neutral range (pH = 7 ± 0.3) across all treatment groups. Except for the CB0 (CB:HAP = 1:0) and CB2.0 (CB:HAP = 1:2) treatments, the remaining treatments significantly reduced the soil EC values by 3.27% to 47.92%. All treatments significantly increased the contents of alkali-hydrolysable nitrogen (AHN) (34.89~57.91%), available phosphorus (AP) (35.93~56.55%), and available potassium (AK) (36.41~56.80%) in the soil. In comparison, although the SB treatment was more effective in regulating the pH and electrical conductivity (EC) of saline-alkali soil than the CB treatment, it was less effective in promoting plant growth in the short term. Through correlation analysis and redundancy analysis, a significant positive correlation was found between soil pH and ryegrass germination rate and plant height, particularly with the most pronounced impact on soil pH observed in the CB1.0 and SB0 (SB:HAP = 1:0) treatments. This study underscores the potential of CB/SB-SA-HAP composite materials in soil improvement and plant growth promotion, providing valuable insights for soil remediation, enhancement, and plant cultivation advancements in the agricultural sector.

Potential selection of antimony and methotrexate cross-resistance in Leishmania infantum circulating strains.

Visceral leishmaniasis (VL) resolution depends on a wide range of factors, including the instauration of an effective treatment coupled to a functional host immune system. Patients with a depressed immune system, like the ones receiving methotrexate (MTX), are at higher risk of developing VL and refusing antileishmanial drugs. Moreover, the alarmingly growing levels of antimicrobial resistance, especially in endemic areas, contribute to the increasing the burden of this complex zoonotic disease. To understand the potential links between immunosuppressants and antileishmanial drugs, we have studied the interaction of antimony (Sb) and MTX in a Leishmania infantum reference strain (LiWT) and in two L. infantum clinical strains (LiFS-A and LiFS-B) naturally circulating in non-treated VL dogs in Spain. The LiFS-A strain was isolated before Sb treatment in a case that responded positively to the treatment, while the LiFS-B strain was recovered from a dog before Sb treatment, with the dog later relapsing after the treatment. Our results show that, exposure to Sb or MTX leads to an increase in the production of reactive oxygen species (ROS) in LiWT which correlates with a sensitive phenotype against both drugs in promastigotes and intracellular amastigotes. LiFS-A was sensitive against Sb but resistant against MTX, displaying high levels of protection against ROS when exposed to MTX. LiFS-B was resistant to both drugs. Evaluation of the melting proteomes of the two LiFS, in the presence and absence of Sb and MTX, showed a differential enrichment of direct and indirect targets for both drugs, including common and unique pathways. Our results show the potential selection of Sb-MTX cross-resistant parasites in the field, pointing to the possibility to undermine antileishmanial treatment of those patients being treated with immunosuppressant drugs in Leishmania endemic areas.

Sensor-Based Fertigation Management Enhances Resource Utilization and Crop Performance in Soilless Strawberry Cultivation

The use of wireless sensors for real-time sensing of substrate water status and electrical conductivity could be an effective tool for precision irrigation management in soilless cultivation. In this research, the effects of timer-based (TB) compared to smart sensor-based irrigation (SB) were investigated. The highest consumption of fertilizers and water were recorded in TB, with nutrient solution and total applied water savings of 38% and 26%, respectively, in SB. The highest yield was obtained in SB treatment, with a total and marketable yield decrease of 7% in TB, with no differences in terms of the total soluble solids content, dry matter, firmness, juice pH and titratable acidity of the strawberry fruits. The higher yield, combined with water and nutrient saving in SB, allowed water use efficiency (fresh weight of marketable fruits per liter of total water applied) to be increased by 46% and nutrient productivity (fresh weight of marketable product per gram of nutrient supplied via nutrient solution) by 74%. The study confirms that sensor-based, compared to empiric fertigation management, ameliorates the sustainability of open, free-drain, soilless cultivation of strawberry, leading to better resource use without compromising crop performance and fruit quality.

Effects of Supplementing Milk Replacer with Sodium Butyrate on Dairy Calves.

Diarrhea and respiratory diseases pose significant challenges in the rearing of pre-weaned calves, motivating the investigation of tools to improve gastrointestinal tract development, health, and overall performance in young calves. Consequently, the primary objective of this study was to assess the effectiveness of an additive incorporated into milk replacer to promote the development and health of the animals. Forty-six dairy calves were randomly assigned into two treatments: control (CON, n = 23; with 15 females and 8 males), and sodium butyrate (SB, n = 23; with 15 females and 8 males). The calves in the SB treatment group were supplemented with 4 g/d of unprotected sodium butyrate (Adimix, Adisseo, China), added to the milk replacer from 4 to 60 days of age. Water and starter were fed ad libitum. The study evaluated several parameters, including feed intake, nutrient digestibility, ruminal pH, ammonia and volatile fatty acids, blood metabolites (glucose, insulin-like growth factor type 1, urea, β-hydroxybutyrate), hemogram, health scores, performance, and feed efficiency. Bull calves were euthanized at 60 days of age for organ comparison, while heifer calves were assessed for carryover effects up to 90 days of age. Data were analyzed independently using linear mixed models using the nlme package in R, and the Artools package for non-parametric categorical outcomes. Although the feed intake and performance variables exhibited differences within weeks, no divergence was observed between treatment groups. Notably, a positive treatment-by-week interaction was identified for starter feed intake (p = 0.02) and total dry matter intake (p = 0.04) during pre-weaning for CON animals. Ruminal parameters, blood metabolites, and hemogram values such as glucose, urea, insulin-like growth factor type 1, mean corpuscular value, lymphocytes, and neutrophils displayed differences within weeks during the pre-weaning stage, but similar results within groups. No differences between supplemented and non-supplemented calves were found across nutrient digestibility, organ development, and histology. Regarding health scores, differences were noted within weeks for fecal and respiratory scores during the pre-weaning stage, and only the respiratory score during the post-weaning stage. Consequently, butyrate supplementation did not elicit improvements or negative effects in the body development or health status of dairy calves.

Clinical efficacy of sodium bicarbonate in treating pediatric metabolic acidosis with varying level of acid–base balance parameters: a real-world study

BackgroundSodium bicarbonate (SB) infusion is commonly used to correct metabolic acidosis, but its clinical efficacy remains controversial. This study aims to investigate whether acid–base balance parameters should be a consideration for administering SB treatment.MethodsChildren with metabolic acidosis (pH < 7.35 and bicarbonate < 22 mmol/L) who were treated with or without 50 mg/ml SB injection were grouped and extracted from a retrospective cohort database of the Pediatric Intensive Care Unit. The interaction between acid–base balance parameters and SB treatment on mortality was analyzed through mortality curves and cross-effect models. Logistic regression was conducted to estimate the risk of death following SB treatment in the overall children as well as in subgroups, and potential confounding factors were adjusted for. After employing propensity score matching to account for confounding factors, further analysis was performed to evaluate the effectiveness of SB treatment within each chloride subgroup.ResultsA total of 5865 children with metabolic acidosis were enrolled, of which 2462 (42.0%) received SB treatment. In the overall population, it was found that SB treatment did not reduce hospital mortality or 28-day mortality. Interactions between acid–base balance parameters (chloride and anion gap) and SB treatment on mortality were observed. Subgroup analysis clarified that when chloride levels were below 107 mmol/L, children treated with SB had higher in-hospital mortality (29.8% vs 14.9%) and 28-day mortality (26.5% vs 13.4%), with adjusted ORs of 2.065 (95% CI, 1.435–2.97) and 1.947 (95% CI, 1.332–2.846), respectively. In contrast, when chloride levels were greater than or equal to 113 mmol/L, children treated with SB had a shorter stay in the PICU (median: 1.1 days vs 5.1 days, adjusted p = 0.004) and lower in-hospital mortality (4.3% vs 10.3%) and 28-day mortality (4.0% vs 8.4%), with adjusted ORs of 0.515 (95% CI, 0.337–0.788) and 0.614 (95% CI, 0.391–0.965), respectively. After controlling for confounding factors through matching, the impact of SB treatment on the risk of death in each chloride subgroup was consistent with the aforementioned results. However, treatment with SB did not significantly increase the risk of death in newborns or children with moderate to severe metabolic acidosis when chloride levels were below 107 mmol/L (p > 0.05).ConclusionsThe use of sodium bicarbonate for treating metabolic acidosis has been found to increase mortality in children with low chloride levels but decrease mortality in those with high chloride levels in this study. Further prospective multi-center clinical studies and basic research are needed to validate these findings.

Limonite as a Natural Adsorbent for the Removal of Antimony(III) from an Aqueous Solution

Natural limonite, which contains mainly nano-sized iron and manganese oxides, is widely distributed worldwide. This study investigated the kinetics, thermodynamics, and the effects of pH, ion strength, and anions on the adsorption of Sb(III) via limonites sampled from Xinqiao and Yeshan (Tongling, China). Results show that adsorption equilibrium is achieved after 24 h for all experiments. Under initial Sb(III) = 200 mg/L, pH = 3.0, and temperature = 25 °C, Sb adsorption quantities for X1 (Mn-free limonite from Xinqiao), X2 (Mn-containing limonite from Xinqiao), Y1 (Mn-free limonite from Yeshan), and Y2 (Mn-containing limonite from Yeshan) are 10.92, 12.97, 27.12, and 89.34 mg/g, respectively. Manganese oxides in limonites promote Sb removal through oxidizing Sb(III) to Sb(V). The adsorption processes for all four limonites are fitted with a pseudo-second-order model. All adsorptions except for X1 fit with the Freundlich model; for X1, the Langmuir adsorption model is better. All adsorptions are spontaneous reactions (ΔG &lt; 0). All adsorptions except for Y1 (ΔH &lt; 0, exothermic reaction) are endothermic reactions (ΔH &gt; 0). Antimony adsorption is independent of solution pH for Mn-free limonites but is negatively related to solution pH for Mn-containing limonites. Generally, ion strength has a weak positive effect on Sb adsorption. The effects of anions on Sb adsorption are grouped into three types: weak negative (NO3− and SO42−), negative (CO32−, SiO44−, and PO43−), and equivocal (humic acid). This study indicates that due to a much higher surface area, Yeshan (124.8 m2/g for X1 and 171.7 m2/g for X2) rather than Xinqiao (13.7 m2/g for Y1 and 12.8 m2/g for Y2) limonites are better materials for Sb(III) removal in an aqueous solution. The key factors for the better use of limonite as an Sb(III) treatment material include temperature, pH, ion strength, and Mn content.

Sugarcane bagasse improved growth performance, digestive enzyme activity, microbial dynamics, and mRNA transcripts of immune-, growth, and antioxidant -related genes of Litopenaeus vannamei in a zero-water exchange system

Pacific white shrimp (Litopenaeus vannamei) were grown in a biofloc rearing systems with (control treatment) or without sugarcane bagasse (SB treatment), with 3 replicate systems per treatment. SB, is an economic carbohydrate source. Parameters monitored were water-quality, growth indices, digestive enzymes activity, and microbial dynamics. Messenger RNA levels of immune-related, growth-related, and antioxidant genes in hepatopancreas and muscle and gene's single nucleotide polymorphism (SNP) were also considered. The outdoor ponds (44.5 m3), were each stocked with 600 L. vannamei larvae with an initial weight of 0.024 g) to start a three-month experiment. The biofloc development was in two aerated active suspension tanks to which SB (about 700 g/day, adjusted every two weeks) was added to maintain the of the C/N at 16. The water quality parameters, digestive enzyme activity, growth, and survival (P ≤ 0.05) in the SB group was improved compared to the control. SB also increased the total heterotrophic microbiota compared to the control. The mRNA levels of immune- related genes (lipopolysaccharides/b-glucan- binding protein, β-glucan-binding protein, lysozyme, prophenoloxidase, crustin, transglutaminase, and hemocyanin) and antioxidant genes (superoxide dismutase and glutathione peroxidase) significantly increased in SB group (P ≤ 0.05) compared to the control treatment. The SB group was the highest in all growth- related genes such as insulin- like growth factors (I and II), growth hormone, myosin, and paramyosin. Eight SNPs were detected in the hemocyanin gene, and an adenine insertion (ins A-554) was recorded at a high body weight. Our findings implied that using SB, as a carbon source in biofloc system without artificial feeding, could improve water quality, growth indices, digestive enzymes, microbial dynamics and the mRNA levels of all immune-, growth- related and antioxidant genes in L. vannamei.

Combined effect of hydrothermal treatments and drying temperature on the physicochemical, milling, and nutritional characteristics of foxtail millet

Continuing practice of enhancing palatability and decortication yield of grain, in the present study combined effect of hydrothermal (soak-boil-SB & soak-steam-SS) treatments and drying temperature on physicochemical and milling characteristics of foxtail millet have been evaluated. Results revealed that hydrothermal treatments followed by drying have a significant (p ≤ 0.05) affect on the physicochemical properties of foxtail millet. Head grain yield (HGY) increased by 18.28% in SB treatment and 22.99% in SS-treatment, however, with an increase in the drying temperature, HGY decreased by 2.32–2.88%. The hardness of grains increased by 43.88% in SB, and 70.32% in SS treatments. Owing to more husk removal of 6.70–12.26% in these treatments, decortication yield increased, while brokens decreased by 72.92–91.44%, paving the way for better recovery of HGY. An interesting aspect of hydrothermal treatments was 1.57-fold higher bran separation from decorticated SS40 sample. Hydrothermal treatments and drying temperatures enhanced total carbohydrates decreased components decreased other constituents. Closeness in dimensional properties depicts positive correlation in decorticated foxtail millet as revealed by cluster analysis in the dendrogram. Both hydrothermal treatments significantly decreased the pasting parameters whereas decortication significantly decreased the in-soluble dietary fiber of the whole millet, however, soluble dietary fiber increased by 21.38%.

Selenite affected photosynthesis of Oryza sativa L. exposed to antimonite: Electron transfer, carbon fixation, pigment synthesis via a combined analysis of physiology and transcriptome

Selenium (Se) is a microelement that can counteract (a)biotic stresses in plants. Excess antimony (Sb) will inhibit plant photosynthesis, which can be alleviated by appropriate doses of Se but the associated mechanisms at the molecular levels have not been fully explored. Here, a rice variety (Yongyou 9) was exposed to selenite [Se(IV), 0.2 and 0.8 mg L−1] alone or combined with antimonite [Sb(III), 5 and 10 mg L−1]. When compared to the 10 mg L−1 Sb treatment alone, addition of Se in a dose–dependent manner 1) reduced the heat dissipation efficiency resulting from the inhibited donors, Sb concentrations in shoots and roots, leaf concentrations of fructose, H2O2 and O2•–; 2) enhanced heat dissipation efficiency resulting from the inhibited accepters value, concentrations of Chl a, sucrose and starch, and the enzyme activity of adenosine diphosphate glucose pyrophosphorylase, sucrose phosphate synthase, and sucrose synthase; but 3) did not alter gas exchange parameters, concentrations of Chl b and total Chl, enzyme activity of soluble acid invertase, and values of maximum P700 signal, photochemical efficiency of PSI and electron transport rate of PSI. Se alleviated the damage caused by Sb to the oxygen–evolving complex and promoted the transfer of electrons from QA to QB. When compared to the 10 mg L−1 Sb treatment alone, addition of Se 1) up–regulated genes correlated to synthesis pathways of Chl, carotenoid, sucrose and glucose; 2) disturbed signal transduction pathway of abscisic acid; and 3) upregulated gene expression correlated to photosynthetic complexes (OsFd1, OsFER1 and OsFER2).

Glucocorticoids improve the balance of M1/M2 macrophage polarization in experimental autoimmune uveitis through the P38MAPK-MEF2C axis

Uveitis is a common ocular disease that can induce serious complications and sequelae. It is one of the major causes of blindness. Currently, mounting evidence suggests that glucocorticoids (GCs) can suppress ocular inflammation and promote the healing of damaged ocular tissues, but the underlying mechanism remains unclear. The present study aimed to elucidate the mechanism by which GCs modulate the homeostasis of M1/M2 macrophage polarization in experimental autoimmune uveitis (EAU) through the p38MAPK-MEF2C axis. Female Lewis rats were randomly divided into four groups: a normal control (NC) group, an EAU group, an EAU + glucocorticoid (EAU + GC) group, and an EAU + p38MAPK inhibitor (EAU + SB) group. The EAU model was induced in EAU, EAU + GC, and EAU + SB groups, followed by the treatments of normal saline, GC (predisione), and SB203580, respectively. The findings demonstrated that the rats in GC and SB groups had much less ocular inflammation, and the clinical and pathological scores decreased. Further research revealed that GC and SB treatment could inhibit iNOS and CD86 expression while promoting Arg-1 and CD206 secretion in IRBP-induced uveitis rats. Moreover, we found that the role of GC was similar to the results of SB203580, but the role of GC was masked by the C16-PAF (a p38MAPK activator) treatment. Molecular docking and western blot results confirmed that GC's therapeutic action against EAU is mediated via the p38MAPK-MEF2C axis. It regulates macrophage polarization by encouraging M1 to M2 transition and releasing anti-inflammatory factors.

Transcriptomic analysis reveals the molecular mechanisms of Boehmeria nivea L. in response to antimonite and antimonate stresses

Soil antimony (Sb) pollution is a global concern that threatens food security and human health. Boehmeria nivea L. (ramie) is a promising phytoremediation plant exhibiting high tolerance and enrichment capacity for Sb. To reveal the molecular mechanisms and thus enhance the ramie uptake, transport, and detoxification of Sb with practical strategies, a hydroponic experiment was conducted to compare the physiological and transcriptomic responses of ramie towards antimonite (Sb(Ⅲ)) and antimonate (Sb(Ⅴ)). Phenotypic results showed that Sb(Ⅲ) had a stronger inhibitory effect on the growth of ramie. Root Sb content under Sb(Ⅲ) was 2.43 times higher than that in Sb(Ⅴ) treatment. Based on the ribonucleic acid sequencing (RNA-Seq) technique, 3915 and 999 significant differentially expressed genes (DEGs) were identified under Sb(Ⅲ) and Sb(Ⅴ), respectively. Transcriptomic analysis revealed that ramie showed different adaptation strategies to Sb(Ⅲ) and Sb(V). Key DEGs and their involved pathways such as catalytic activity, carbohydrate metabolisms, phenylpropanoid biosynthesis, and cell wall modification were identified to perform crucial roles in Sb tolerance and detoxification. Two heavy metal-associated domain-type genes, six heavy metal-associated isoprenylated plant proteins, and nine ABC transporters showed possible roles in the transport and detoxification of Sb. The significant upregulation of NRAMP5 and three NIPs suggested their roles in the transport of Sb(V). This study is the basis for future research to identify the exact genes and biological processes that can effectively enhance Sb accumulation or improve plant tolerance to Sb, thereby promoting the phytoremediation of Sb-polluted soils.

Effects of Exogenous Melatonin Treatment on the Growth and Antioxidant System of Rice Seedlings Under Antimony Stress

To investigate the effect of exogenous application of melatonin (MT) on rice seedlings under antimony (Sb) stress, hydroponic experiments were carried out with rice seedlings (Huarun No.2). The fluorescent probe localization technology was used to locate the reactive oxygen species (ROS) in the root tips of rice seedlings, and the root viability, malondialdehyde (MDA) content, ROS (H2O2 and O2-·) content, antioxidant enzyme (SOD, POD, CAT, and APX) activities, and antioxidant (GSH, GSSG, AsA, and DHA) contents in the roots of rice seedlings were analyzed. The results showed that exogenous addition of MT could alleviate the adverse effects of Sb stress on the growth and increase the biomass of rice seedlings. Compared with the Sb treatment, the application of 100 μmol·L-1 MT increased rice root viability and total root length by 44.1% and 34.7% and reduced the content of MDA, H2O2, and O2-· by 30.0%, 32.7%, and 40.5%, respectively. Further, the MT treatment increased the activities of POD and CAT by 54.1% and 21.8%, respectively, and also regulated the AsA-GSH cycle. This research indicated that exogenous application of 100 μmol·L-1MT can promote the growth and antioxidant ability of rice seedlings and alleviate the damage of lipid peroxidation by Sb stress, thus improving the resistance of rice seedlings under Sb stress.

BUTYRATE-INDUCED MITOCHONDRIAL FUNCTION IMPROVES BARRIER FUNCTION IN INFLAMMATORY BOWEL DISEASE (IBD)

Abstract BACKGROUND Short-chain fatty acids (SCFAs), end-product of gut microbial metabolism, play an important role in colonic homeostasis. Butyrate is a prime SCFA that fuels intestinal epithelial cells (IECs). However, this energy source is deficient in inflammatory bowel disease (IBD) due to dysbiotic microbiota. In this study, we posit that butyrate supplementation drives mitochondrial respiration induced barrier function in IBD. METHODS Normal human Colon mucosal (NCM460) epithelial cells were treated overnight with different concentration of sodium butyrate (SB; 0.5-5.0mM) with or without TNF (1ng/ml). To model mitochondrial deficiency, TFAM (mitochondrial transcriptional factor A), was silenced (shTFAM) in NCM460 cells. For mitochondrial respiration assessment, NCM cells were maintained and treated with SB (-/+TNF) under glucose-free medium and Oxygen consumption rate (OCR) was measured using high-throughput Seahorse XFe24 Extracellular Flux Analyzer (Agilent Technologies). Gene expression analysis was determined by RT-qPCR from total RNA isolated from untreated and treated NCM cells as well as in mitochondria-deficient shTFAM NCMs compared to shControl cells. All assays were performed in triplicate and fold changes were calculated using the ΔΔCT method. RESULT Seahorse analysis showed significant increase in Maximal respiratory capacity, spare respiratory capacity and ATP production at sub-optimal (2mM) and optimal (5mM) SB concentrations, suggesting a SB induced mitochondrial respiration and capacity to overcome oxidative stress. At molecular level, SB significantly increased the expression of genes associated with mitochondrial biogenesis (TFAM), complex I (Ndufa1, Ndufa4, Ndufa6), complex IV (Cox6A1) and complex V (ATP5E, ATP8), at optimal 5mM concentration. The effect of SB was more pronounced under inflammatory condition when NCM cells were treated in the presence of low dose TNF. Further transcriptomic analysis of TFAM-deficient NCMs demonstrated significant decrease in mRNA of major butyrate transporters (MCT1, MCT4, ABCG2) compared to TFAM-proficient shControl cells, irrespective of any treatment. Similar decreased expression pattern was observed for tight junction genes (ZO1 and Occludin) in shTFAM compared to shControl cells. However, butyrate transporters and ZO1 mRNA increased significantly in both shTFAM and shControl cells after SB treatment at sub-optimal concentration (2mM) in the presence of TNF. Interestingly, only shTFAM cells showed increase in transcript level of Occludin after SB+TNF treatment, with no effect in shControl. CONCLUSION These data suggest that butyrate metabolism is a critical player in promoting oxidative health of mitochondria, which further drives transporter-mediated butyrate utilization and promotes barrier integrity under inflammatory conditions as in IBD.

Impact of Saccharomyces boulardii CNCM I-745 on Bacterial Overgrowth and Composition of Intestinal Microbiota in Diarrhea-Predominant Irritable Bowel Syndrome Patients: Results of a Randomized Pilot Study

Background: Small intestinal bacterial overgrowth (SIBO) is associated with diarrhea-predominant irritable bowel syndrome (IBS-D). Probiotics like Saccharomyces boulardii CNCM I-745 (Sb) may be efficacious in balancing the microbiota. This randomized open label study assessed the effect of Sb in patients with bacterial overgrowth associated with IBS-D and its impact on the intestinal microbiota. Methods: Patients were randomized to receive Sb + dietary advice (Sb + DA) or dietary advice (DA) only for 15 days. SIBO was assessed by the lactulose hydrogen breath test (LHBT). Symptoms were assessed with the IBS Symptom Severity Scale (IBS-SSS) and stool consistency with the Bristol Stool Form Scale. Microbiota and mycobiota were analyzed by 16S rDNA and ITS2. Results: 54 patients were included, among whom 48 (27 Sb + DA, 21 DA) were evaluated. Decrease of hydrogen excretion was slightly higher in Sb + DA group, 41% versus 29% in DA group, and IBS-SSS total score were reduced by −134 and −93, respectively. The proportion of patients with diarrhea was lower in the Sb + DA group than in the DA group (25.9% compared to 47.6%). Bacterial and fungal microbiota showed that Sb treatment was associated with several modifications. Interestingly, F. prausnitzii was more abundant in Sb-treated patients with marked clinical improvement. The safety of S. boulardii CNCM I-745 was excellent. Conclusions: In patients with SIBO, S. boulardii CNCM I-745 associated with dietary advice reduced bacterial overgrowth and improved digestive symptoms while restoring the intestinal microbiota. The increased abundance of F. prausnitzii coupled with symptom improvement merits further research.

Effects of antimony stress on growth, structure, enzyme activity and metabolism of Nipponbare rice (Oryza sativa L.) roots

Some antimony (Sb) contaminated areas are used for rice cultivation in response to economic demands. However, little is known about the effects of Sb stress on the growth and metabolism of rice roots. Thus, a hydroponic experiment was carried out on the growth, root anatomy, enzyme activity, and metabolism of Nipponbare rice (Oryza sativa L. ssp. japonica cv. Nipponbare) under varying levels of Sb (III) stress (0 mg L−1, 10 mg L−1, and 50 mg L−1). With the increase of Sb concentration, rice root length and root fresh weight declined by 67.8 % and 90.5 % for 10 mg L−1 Sb stress and 94.1 % and 98.4 % for 50 mg L−1 Sb stress, respectively. Anatomical analysis of cross-sections of Sb-treated roots showed an increase in cell wall thickness and an increase in the number of cell mitochondria. The 10 mg L−1 and 50 mg L−1 Sb stress increased the activity of enzyme superoxide dismutase (SOD) in root cells by 1.94 and 2.40 times, respectively. Compared to the control, 10 mg L−1 Sb treatment increased the activity of catalase (CAT) and peroxidase (POD), as well as the concentrations of antioxidant glutathione (GSH) in the root by 1.46, 1.38, and 0.52 times, respectively. However, 50 mg L−1 Sb treatment significantly decreased the activity or content of CAT, POD and GSH by 28.1 %, 13.5 % and 28.2 %, respectively. Nontargeted LC/MS-based metabolomics analysis identified 23 and 13 significantly differential metabolites in rice roots exposed to 10 mg L−1 and 50 mg L−1 Sb, respectively, compared to the control. These differential metabolites were involved in four main metabolic pathways including the tricarboxylic acid cycle (TCA cycle), butanoate metabolism, alanine, aspartate and glutamate metabolism, and alpha-linolenic acid metabolism. Taken together, these findings indicate that Sb stress destroys the structure of rice roots, changes the activity of enzymes, and affects the metabolic pathway, thereby reducing the growth of rice roots and leading to toxicity.

GPX4 degradation via chaperone-mediated autophagy contributes to antimony-triggered neuronal ferroptosis

Exposure to antimony (Sb), recently identified as a nerve pollutant, can result in neuron damage; but, associated-neurotoxicological mechanisms were still not clear. Herein, we assessed the role of ferroptosis in Sb-mediated neurotoxicity and clarified the underlying mechanism. Following Sb exposure, ferroptosis was significantly promoted in vivo and in vitro. Moreover, following use of ferrostatin-1 (fer-1) to inhibit ferroptosis, Sb-induced ferroptosis in PC12 cells was effectively attenuated. Sb accelerated lysosomal transport and subsequent degradation of glutathione peroxidase 4 (GPX4), resulting in ferroptosis. Furthermore, chaperone-mediated autophagy (CMA) was activated following treatment with Sb, while inhibition of CMA by lysosomal associated protein 2 A (LAMP2A) knockdown attenuated Sb-induced GPX4 degradation. Sb treatment also increased expression of the chaperones heat shock cognate protein 70 (HSC70) and heat shock protein 90 (HSP90) and the lysosome receptor LAMP2A, and increased binding of HSP90, HSC70, and LAMP2A with GPX4 was observed, indicating increased formation of the chaperone-GPX4 complex. Finally, GPX4 overexpression significantly protected PC12 cells from activation of Sb-stimulated ferroptosis and subsequent cytotoxicity. Collectively, our results provide a original mechanism by which Sb triggers neurotoxicity, to concluded that Sb stimulates neuronal ferroptosis through CMA-mediated GPX4 degradation.

Effective Sb(V) removal from aqueous solution using phosphogypsum-modified biochar

Antimonate is the dominant form of antimony (Sb) in Sb mine water. The treatment of high-Sb mine water essentially reduces the discharge of antimonate oxyanions ([Sb(OH)6]−) in it. Biochar obtained from phosphogypsum-modified anaerobic digested distillers’ grain (PADC) can effectively adsorb antimonate from water. In this work, using batch adsorption experiments, mathematical models, and characterization methods, the mechanism of Sb(V) adsorption by PADC was studied. Compared with pristine biochar, PADC biochar showed abundant lamellar and vesicular structures with significant calcium ion loading on the surface. The kinetics data of the adsorption of Sb(V) on the PADC biochar followed the Elovich equation (R2 = 0.992), indicating that heterogeneous adsorption had occurred. The results also showed that intraparticle diffusion played an important role in controlling Sb(V) adsorption by PADC biochar. The Redlich–Peterson model best fit the Sb(V) adsorption isotherm (R2 = 0.997), indicating that the adsorption was a combination of the Langmuir and Freundlich models. The maximum adsorption capacity of PADC biochar for Sb(V) is 8123 mg/kg, which is more than twice that of the pristine biochar (3487 mg/kg) and is sufficient for Sb(V) treatment in most mine water. Fourier transform infrared (FTIR) spectra, X-ray photoelectron spectroscopy (XPS), X-ray diffractometry (XRD), and Transmission electron microscopy with energy dispersive X-ray spectroscopy (TEM-EDS) analyses revealed that the dominant mechanism of Sb(V) removal by PADC biochar was the formation of Ca–O–Sb complexes or amorphous surface precipitation as well as electrostatic adsorption. This work demonstrated the potential of PADC biochar in the treatment of Sb-contaminated mine water.