Supplementation with grape seed extract, onion peel extract, or rosemary extract in the diet alleviates growth inhibition, liver damage, and oxidative stress induced by diquat in Lohmann chicks.

The present study aimed to assess the impact of grape seed extract (GSE), onion peel extract (OPE), and rosemary extract (ROE) on Diquat-induced growth restriction and oxidative stress in Lohmann chicks. A total of 200 chicks were randomly assigned to 5 diets: the positive control (PC) group, the negative control (NC) group, GSE group, OPE group, and ROE group. During the first 7 d of trial, compared with NC and PC groups, the GSE group enhanced average daily feed intake (ADFI). From day 8-21, diquat injection resulted in reduced growth performance, increased platelet volume distribution width (PWD), malondialdehyde (MDA) concentration, and activities of alanine aminotransferase (ALT) in chick serum; it also decreased total protein (TP), albumin (ALB), globulin (GLB) concentration, activities of superoxide dismutase (SOD) and glutathione S-transferase (GST) in chick serum; furthermore, it increased MDA concentration while decreasing GST activities in liver. The NC group exhibited lower average daily gain (ADG) than other groups. Compared with NC group, GSE group reduced ALT activities, MDA levels, and red cell distribution width (RDW), and PDW concentration; it also increased SOD, GST activities. The ROE group lowered ALT activities and MDA concentration. The OPE group decreased ALT activities, and MDA levels, RDW, and PDW concentration, and increased SOD activities of chicks. These results suggest that supplementing antioxidants in diets alleviated oxidative stress in chicks challenged by improving antioxidant capacity and liver function.

Dietary curcumin supplementation alleviates diquat-induced oxidative stress in the liver of broilers.

This study purposed to investigate the alleviating effect of dietary curcumin supplementation on oxidative stress in the liver of broilers induced by diquat. One-day-old Cobb broilers (400) were selected and randomly divided into 5 groups, with 8 replicates and 10 broilers per replicate. The control group and the diquat group were fed the basal diet, while the curcumin supplementation groups were fed the basal diet supplemented with different amounts of curcumin (50, 100, and 150 mg/kg). On d 21 of the test, 1 broiler was randomly selected from each replicate and intraperitoneally injected with 20 mg/mL of diquat solution at a dose of 1 mL/kg BW or equivalent physiological saline (for the control group). After 48 h of feeding, the selected broilers were slaughtered for analysis. The results show that diquat treatment reduced the antioxidant capacity of the liver, caused oxidative stress, and affected its lipid metabolism. However, diet supplementation using curcumin completely or partially reversed the effect of diquat on the liver of broilers. The blood alanine aminotransferase activity, total bilirubin and total protein levels, and liver Caspase-3 mRNA abundance in broilers were lower or significantly lower in the curcumin supplementation group than in the diquat group (P < 0.05). The curcumin supplementation groups had significantly higher total antioxidant capacity activity but significantly lower malondialdehyde in the liver of broilers than the diquat group (P < 0.05). The blood triglyceride level of broilers was lower or significantly lower in the curcumin supplementation groups than in the diquat group (P < 0.05). The activities of cetyl coenzyme A carboxylase in the liver were significantly lower in the 150 mg/kg curcumin supplementation groups than in the DQ group (P < 0.05). In conclusion, dietary curcumin supplementation could ameliorate the effects of diquat-induced oxidative stress on the antioxidant capacity, tissue morphology, and lipid metabolism of the liver of broilers, thus protecting the liver. The recommended dosage for broiler diets is 100 to 150 mg/kg curcumin.

[Experimental study on the toxicokinetics and gastrointestinal damage in rats poisoned with acute diquat poisoning at different exposure doses].

OBJECTIVE: To observe the toxicokinetic parameters, absorption characteristics and pathomorphological damage in different parts of the gastrointestinal tract of rats poisoned with different doses of diquat (DQ). METHODS: Ninety-six healthy male Wistar rats were randomly divided into a control group (six rats) and low (115.5 mg/kg), medium (231.0 mg/kg) and high (346.5 mg/kg) dose DQ poisoning groups (thirty rats in each dose group), and then the poisoning groups were randomly divided into 5 subgroups according to the time after exposure (15 minutes and 1, 3, 12, 36 hours; six rats in each subgroup). All rats in the exposure groups were given a single dose of DQ by gavage. Rats in the control group was given the same amount of saline by gavage. The general condition of the rats was recorded. Blood was collected from the inner canthus of the eye at 3 time points in each subgroup, and rats were sacrificed after the third blood collection to obtain gastrointestinal specimens. DQ concentrations in plasma and tissues were determined by ultra-high performance liquid chromatography and mass spectrometry (UPHLC-MS), and the toxic concentration-time curves were plotted to calculate the toxicokinetic parameters; the morphological structure of the intestine was observed under light microscopy, and the villi height and crypt depth were determined and the ratio (V/C) was calculated. RESULTS: DQ was detected in the plasma of the rats in the low, medium and high dose groups 5 minutes after exposure. The time to maximum plasma concentration (Tmax) was (0.85±0.22), (0.75±0.25) and (0.25±0.00) hours, respectively. The trend of plasma DQ concentration over time was similar in the three dose groups, but the plasma DQ concentration increased again at 36 hours in the high dose group. In terms of DQ concentration in gastrointestinal tissues, the highest concentrations of DQ were found in the stomach and small intestine from 15 minutes to 1 hour and in the colon at 3 hours. By 36 hours after poisoning, the concentrations of DQ in all parts of the stomach and intestine in the low and medium dose groups had decreased to lower levels. Gastrointestinal tissue (except jejunum) DQ concentrations in the high dose group tended to increase from 12 hours. Higher doses of DQ were still detectable [gastric, duodenal, ileal and colonic DQ concentrations of 6 400.0 (1 232.5), 4 889.0 (6 070.5), 10 300.0 (3 565.0) and 1 835.0 (202.5) mg/kg respectively]. Light microscopic observation of morphological and histopathological changes in the intestine shows that acute damage to the stomach, duodenum and jejunum of rats was observed 15 minutes after each dose of DQ, pathological lesions were observed in the ileum and colon 1 hour after exposure, the most severe gastrointestinal injury occurred at 12 hours, significant reduction in villi height, significant increase in crypt depth and lowest V/C ratio in all segments of the small intestine, damage begins to diminish by 36-hour post-intoxication. At the same time, morphological and histopathological damage to the intestine of rats at all time points increased significantly with increasing doses of the toxin. CONCLUSIONS: The absorption of DQ in the digestive tract is rapid, and all segments of the gastrointestinal tract may absorb DQ. The toxicokinetics of DQ-tainted rats at different times and doses have different characteristics. In terms of timing, gastrointestinal damage was seen at 15 minutes after DQ, and began to diminish at 36 hours. In terms of dose, Tmax was advanced with the increase of dose and the peak time was shorter. The damage to the digestive system of DQ is closely related to the dose and retention time of the poison exposure.

Pterostilbene Confers Protection against Diquat-Induced Intestinal Damage with Potential Regulation of Redox Status and Ferroptosis in Broiler Chickens.

Oxidative stress causes damage to macromolecules, including proteins, DNA, and lipid, and has been recognized as a crucial driver of the onset and progression of several intestinal disorders. Pterostilbene, one of the natural antioxidants, has attracted considerable attention owing to its multiple biological activities. In the present study, we established an oxidative stress model in broiler chickens via injection with diquat to investigate whether pterostilbene could attenuate diquat-induced intestinal damage and reveal the underlying mechanisms. We found that diquat-induced decreases in the activities of superoxide dismutase and glutathione peroxidase and the level of reduced glutathione and the increase in hydrogen peroxide content in plasma and jejunum were significantly alleviated by pterostilbene (P < 0.05). Pterostilbene supplementation also decreased intestinal permeability and jejunal apoptosis rate, improved jejunal villus height and the ratio of villus height to crypt depth, and promoted the transcription and translation of jejunal tight junction proteins occludin and zona occludens 1 in diquat-challenged broilers (P < 0.05). Furthermore, pterostilbene reversed diquat-induced mitochondrial injury in the jejunum, as indicated by the decreased reactive oxygen species level and elevated activities of superoxide dismutase 2 and mitochondrial respiratory complexes (P < 0.05). Importantly, administering pterostilbene maintained iron homeostasis, inhibited lipid peroxidation, and regulated the expression of the markers of ferroptosis in the jejunum of diquat-exposed broilers (P < 0.05). The nuclear factor erythroid 2-related factor 2 signaling pathway in the jejunum of diquat-exposed broilers was also activated by pterostilbene (P < 0.05). In conclusion, our study provides evidence that pterostilbene alleviates diquat-induced intestinal mucosa injury and barrier dysfunction by strengthening antioxidant capacity and regulating ferroptosis of broiler chickens.

Effects of dietary supplementation with chlorogenic acid on growth performance, antioxidant capacity, and hepatic inflammation in broiler chickens subjected to diquat-induced oxidative stress.

This study was conducted to investigate the protective effects of chlorogenic acid (CGA) on broilers subjected to (DQ)-induced oxidative stress. In experiment 1, one hundred and ninety-two male one-day-old Ross 308 broiler chicks were distributed into 4 groups and fed a basal diet supplemented with 0, 250, 500, or 1,000 mg/kg CGA for 21 d. In experiment 2, an equivalent number of male one-day-old chicks were allocated to 4 treatments for a 21-d trial: 1) Control group, normal birds fed a basal diet; 2) DQ group, DQ-challenged birds fed a basal diet; and 3) and 4) CGA-treated groups: DQ-challenged birds fed a basal diet supplemented with 500 or 1,000 mg/kg CGA. The intraperitoneal DQ challenge was performed at 20 d. In experiment 1, CGA administration linearly increased 21-d body weight, and weight gain and feed intake during 1 to 21 d (P < 0.05). CGA linearly and/or quadratically increased total antioxidant capacity, catalase, superoxide dismutase, and glutathione peroxidase activities, elevated glutathione level, and reduced malondialdehyde accumulation in serum, liver, and/or jejunum (P < 0.05). In experiment 2, compared with the control group, DQ challenge reduced body weight ratio (P < 0.05), which was reversed by CGA administration (P < 0.05). DQ challenge increased serum total protein level, aspartate aminotransferase activity, and total bilirubin concentration (P < 0.05), which were normalized when supplementing 500 mg/kg and/or 1,000 mg/kg CGA (P < 0.05). DQ administration elevated hepatic interleukin-1ß, tumor necrosis factor-α, and interleukin-6 levels (P < 0.05), and the values of interleukin-1ß were normalized to control values when supplementing CGA (P < 0.05). DQ injection decreased serum superoxide dismutase activity, hepatic catalase activity, and serum and hepatic glutathione level, but increased malondialdehyde concentration in serum and liver (P < 0.05), and the values of these parameters (except hepatic catalase activity) were reversed by 500 and/or 1,000 mg/kg CGA. The results suggested that CGA could improve growth performance, alleviate oxidative stress, and ameliorate hepatic inflammation in DQ-challenged broilers.

Hydroxytyrosol attenuates diquat-induced oxidative stress by activating Nrf2 pathway and modulating colonic microbiota in mice.

This study was conducted to investigate the antioxidant effects of hydroxytyrosol (HT) administration in diquat (DQ)-challenged mice. The results showed that HT treatment markedly alleviated DQ-induced oxidative stress, which was indicated by the enhanced total antioxidant capacity (T-AOC), increased activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase and decreased malondialdehyde (MDA) concentration in serum. Additionally, HT increased the mRNA expression levels of NF-E2-related factor 2 (Nrf2) and its downstream genes, including NADPH quinone oxidoreductase 1 (NQO1) and catalase (CAT) in the small intestine of DQ-challenged mice. 16S rRNA gene sequencing results showed that HT treatment increased the relative abundance of Firmicutes and Lactobacillus and decreased the relative abundance of Bacteroidetes. Interestingly, Pearson correlation analysis showed that there were strong association between colonic Firmicutes, Lactobacillus, and Bacteroidetes and the activities of serum antioxidant enzymes. Meanwhile, HT significantly enhanced the colonic butyrate concentration in DQ-challenged mice. Additionally, HT treatment decreased the serum metabolites involving in glycerophospholipid metabolism, pentose, and glucuronate interconversions, which were associated with alleviated oxidative stress. These results indicate that oral administration of 100 mg/kg body weight HT alleviates oxidative stress in DQ-challenged mice, which may involve Nrf2 signaling pathways via modulation of colonic microbiota.

Effects of L-theanine on intestinal morphology, barrier function, and MAPK signaling pathways in diquat-challenged piglets.

This study aimed to explore the protective effects of L-theanine supplementation on the diquat-challenged weaned piglets. A total of 160 weaned piglets were randomly divided into 4 groups using a 2 × 2 two-factor design, there were 4 replicates per group and 10 pigs per replicate. Piglets were fed diets (with 1000 mg/kg L-theanine addition or not), then challenged with diquat or saline on day 7. 21 days after challenge, two pigs from each replicate were selected for sample collection. Results showed that supplement with 1000 mg/kg L-theanine down-regulated the diarrhea rate, serum D-lactate level, tumor necrosis factor-α, and phosphorylation of extracellular regulated protein kinases (ERK1/2), p38 mitogen-activated protein kinase (MAPK), and c-Jun N-terminal kinase (JNK) signaling in pigs without diquat challenge (p < 0.05). While for diquat-challenged piglets, L-theanine addition increased average daily gain, jejunum villus height, and interferon-γ level (p < 0.05). Meanwhile, L-theanine addition decreased the diarrhea rates and mortality, serum D-lactate level, and phosphorylation of ERK and JNK in diquat-challenged pigs (p < 0.05). These results demonstrate that L-theanine pretreatment could alleviate diquat-induced oxidative stress and improve intestinal barrier function in diquat-challenged weaned piglets, which can be attributed to suppression of MAPK phosphorylation signaling pathways.

Experimental study on the toxicokinetics and gastrointestinal damage in rats poisoned with acute diquat poisoning at different exposure doses / 中华危重病急救医学

OBJECTIVE@#To observe the toxicokinetic parameters, absorption characteristics and pathomorphological damage in different parts of the gastrointestinal tract of rats poisoned with different doses of diquat (DQ).@*METHODS@#Ninety-six healthy male Wistar rats were randomly divided into a control group (six rats) and low (115.5 mg/kg), medium (231.0 mg/kg) and high (346.5 mg/kg) dose DQ poisoning groups (thirty rats in each dose group), and then the poisoning groups were randomly divided into 5 subgroups according to the time after exposure (15 minutes and 1, 3, 12, 36 hours; six rats in each subgroup). All rats in the exposure groups were given a single dose of DQ by gavage. Rats in the control group was given the same amount of saline by gavage. The general condition of the rats was recorded. Blood was collected from the inner canthus of the eye at 3 time points in each subgroup, and rats were sacrificed after the third blood collection to obtain gastrointestinal specimens. DQ concentrations in plasma and tissues were determined by ultra-high performance liquid chromatography and mass spectrometry (UPHLC-MS), and the toxic concentration-time curves were plotted to calculate the toxicokinetic parameters; the morphological structure of the intestine was observed under light microscopy, and the villi height and crypt depth were determined and the ratio (V/C) was calculated.@*RESULTS@#DQ was detected in the plasma of the rats in the low, medium and high dose groups 5 minutes after exposure. The time to maximum plasma concentration (Tmax) was (0.85±0.22), (0.75±0.25) and (0.25±0.00) hours, respectively. The trend of plasma DQ concentration over time was similar in the three dose groups, but the plasma DQ concentration increased again at 36 hours in the high dose group. In terms of DQ concentration in gastrointestinal tissues, the highest concentrations of DQ were found in the stomach and small intestine from 15 minutes to 1 hour and in the colon at 3 hours. By 36 hours after poisoning, the concentrations of DQ in all parts of the stomach and intestine in the low and medium dose groups had decreased to lower levels. Gastrointestinal tissue (except jejunum) DQ concentrations in the high dose group tended to increase from 12 hours. Higher doses of DQ were still detectable [gastric, duodenal, ileal and colonic DQ concentrations of 6 400.0 (1 232.5), 4 889.0 (6 070.5), 10 300.0 (3 565.0) and 1 835.0 (202.5) mg/kg respectively]. Light microscopic observation of morphological and histopathological changes in the intestine shows that acute damage to the stomach, duodenum and jejunum of rats was observed 15 minutes after each dose of DQ, pathological lesions were observed in the ileum and colon 1 hour after exposure, the most severe gastrointestinal injury occurred at 12 hours, significant reduction in villi height, significant increase in crypt depth and lowest V/C ratio in all segments of the small intestine, damage begins to diminish by 36-hour post-intoxication. At the same time, morphological and histopathological damage to the intestine of rats at all time points increased significantly with increasing doses of the toxin.@*CONCLUSIONS@#The absorption of DQ in the digestive tract is rapid, and all segments of the gastrointestinal tract may absorb DQ. The toxicokinetics of DQ-tainted rats at different times and doses have different characteristics. In terms of timing, gastrointestinal damage was seen at 15 minutes after DQ, and began to diminish at 36 hours. In terms of dose, Tmax was advanced with the increase of dose and the peak time was shorter. The damage to the digestive system of DQ is closely related to the dose and retention time of the poison exposure.

Simultaneous determination of diquat and its two primary metabolites in rat plasma by ultraperformance liquid chromatography-tandem mass spectrometry and its application to the toxicokinetic study.

PURPOSE: This study aimed to develop and validate an ultraperformance liquid chromatography-tandem mass spectrometry to simultaneously determine diquat (DQ) and its two primary metabolites in rat plasma and its application to the toxicokinetic study. METHOD: The chromatographic separation of DQ and its two primary metabolites was performed with hydrophilic interaction chromatography column by adding formic acid and ammonium acetate in mobile phase in stepwise elution mode. DQ and its two primary metabolites were detected by liquid chromatography-tandem mass spectrometry in positive mode. RESULTS: The lower limit of quantification ranging from 0.3 to 3.0 ng/mL for DQ and its two primary metabolites was achieved by using only 50 µL of rat plasma. The maximum concentration (Cmax) was 977 ng/mL, half-life (t1/2) was 13.1 h, and area under the plasma concentration-time curve (AUC0-t) was 2770 h*ng/mL for DQ, Cmax was 47.1 ng/mL, t1/2 was 25.1 h, and AUC0-t was 180 h·ng/mL for diquat monopyridone (DQ-M) and Cmax was 246 ng/mL, t1/2 was 8.2 h, and AUC0-t was 2430 h·ng/mL for diquat dipyridone (DQ-D), respectively. CONCLUSIONS: The validated method was shown to be suitable for simultaneous determination of diquat and its two primary metabolites in rat plasma. This study is the first to study the toxicokinetics of DQ and its two primary metabolites.

Protective effect of biogenic selenium nanoparticles against diquat-induced acute toxicity via regulation of gut microbiota and its metabolites.

Selenium nanoparticles (SeNPs) with unique biological properties have been suggested as a safer and more effective platform for delivering of Selenium for biological needs. In this study, we investigated the association between gut microbiota altered by SeNPs supplementation and its metabolites under oxidative stress conditions through 16S rDNA gene sequencing analysis and untargeted metabolomics. The results showed that dietary supplementation with SeNPs attenuated diquat-induced acute toxicity in mice, as demonstrated by lower levels of inflammatory effector cells, and biochemical markers in serum such as aspartate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN) and lactate dehydrogenase (LDH). SeNPs also reversed the perturbed gut microbiota composition induced by diquat, decreased the Firmicutes/Bacteroidetes ratio, and increased the abundance of beneficial bacteria such as Akkermansia, Muribaculaceae, Bacteroides and Parabacteroides. Untargeted fecal metabolomics showed that SeNPs can regulate the production of steroids and steroid derivatives, organonitrogen compounds, pyridines and derivatives and other metabolites. Microbiome-metabolome correlation analysis suggested that Parabacteroides was the key bacteria for the SeNPs intervention, which might upregulate the levels of metabolites such as trimethaphan, emedastine, berberine, desoxycortone, tetrahydrocortisone. This study demonstrated that dietary SeNPs supplementation can extensively modulate the gut microbiota and its metabolism, thereby alleviating diquat-induced acute toxicity.

Metabolomics analysis of the potential toxicological mechanisms of diquat dibromide herbicide in adult zebrafish (Danio rerio) liver.

Although diquat is a widely used water-soluble herbicide in the world, its sublethal adverse effects to fish have not been well characterised. In this study, histopathological examination and biochemical assays were applied to assess hepatotoxicity and combined with gas chromatography-mass spectrometry (GC-MS)-based metabolomics analysis to reveal overall metabolic mechanisms in the liver of zebrafish (Danio rerio) after diquat exposure at concentrations of 0.34 and 1.69 mg·L-1 for 21 days. Results indicated that 1.69 mg·L-1 diquat exposure caused cellular vacuolisation and degeneration with nuclear abnormality and led to the disturbance of antioxidative system and dysfunction in the liver. No evident pathological injury was detected, and changes in liver biochemistry were not obvious in the fish exposed to 0.34 mg·L-1 diquat. Multivariate statistical analysis revealed differences between profiles obtained by GC-MS spectrometry from control and two treatment groups. A total of 17 and 22 metabolites belonging to different classes were identified following exposure to 0.34 and 1.69 mg·L-1 diquat, respectively. The metabolic changes in the liver of zebrafish are mainly manifested as inhibition of energy metabolism, disorders of amino acid metabolism and reduction of antioxidant capacity caused by 1.69 mg·L-1 diquat exposure. The energy metabolism of zebrafish exposed to 0.34 mg·L-1 diquat was more inclined to rely on anaerobic glycolysis than that of normal zebrafish, and interference effects on lipid metabolism were observed. The metabolomics approach provided an innovative perspective to explore possible hepatic damages on fish induced by diquat as a basis for further research.

Effects of Curcumin on Mitochondrial Function, Endoplasmic Reticulum Stress, and Mitochondria-Associated Endoplasmic Reticulum Membranes in the Jejunum of Oxidative Stress Piglets.

Mitochondria-associated endoplasmic reticulum (ER) membranes (MAMs) are not only critical for the communication between two organelles but also crucial for cellular processes such as energy metabolism, calcium signaling, and mitochondrial dynamics. The effects of curcumin on jejunal mitochondria, ER, and MAMs in piglets under diquat-induced oxidative stress were assessed. Twenty-four piglets (35 days old, weaned at 21 days, 9.54 ± 0.28 kg, six piglets per group) were used in the study: (1) control group; (2) control + curcumin group; (3) diquat group; and (4) diquat + curcumin group. Curcumin was mixed with the basic diet at 200 mg/kg and fed to piglets. Piglets were administered intraperitoneally of 0.9% saline solution or diquat at 10 mg/kg body weight on the first day. Compared with the diquat group, curcumin improved jejunal morphology and barrier function. Meanwhile, curcumin improved mitochondrial function and ultrastructure, alleviated endoplasmic reticulum stress (ERS), and inhibited apoptosis induced by diquat. Moreover, curcumin prevented excessive MAM formation and alleviated MAM disorder. In conclusion, dietary curcumin ameliorated jejunal damage and mitochondrial dysfunction, attenuated ERS, and alleviated MAM disorder in oxidative stress piglets induced by diquat.

Ellagic Acid Alleviates Diquat-Induced Jejunum Oxidative Stress in C57BL/6 Mice through Activating Nrf2 Mediated Signaling Pathway.

Ellagic acid (EA) is the main constituent found in pomegranate rind, which has anti-inflammatory and antioxidant effects. However, whether EA can alleviate diquat-induced oxidative stress is still unknown. Here, the effects and mechanisms of EA on jejunum oxidative stress induced by diquat was investigated. Oxidative stress was induced in mice by administrating diquat (25 mg/kg body weight) followed by treatment with 100 mg/kg body weight EA for 5 days. Results showed that oral administration of EA significantly ameliorated diquat-induced weight loss and oxidative stress (p < 0.05) evidenced by reduced ROS production in the jejunum. Furthermore, EA up-regulated the mRNA expression of the antioxidant enzymes (Nrf2, GPX1 and HO-1) when mice were challenged with diquat, compared with the diquat group (p < 0.05). Importantly, pharmacological inhibition of Nrf2 by ML385 counteracted the EA-mediated alleviation of jejunum oxidative stress, as evidence by body weight and ROS production. Also, immunohistochemistry staining confirmed the markedly decreased jejunal Nrf2 expression. The up-regulated effect on NQO1 and HO-1 mRNA expression induced by EA was diminished in mice treated with ML385 (p < 0.05). Together, our results demonstrated that therapeutic and preventative EA treatment was effective in reducing weight loss and oxidative stress induced by diquat through the Nrf2 mediated signaling pathway.

Characteristics of circRNAs expression profiles in the piglets intestine induced by oxidative stress.

BACKGROUD: Oxidative stress (OS) can affect the expression of key genes and destroy the intestinal structure. However, it is unclear how OS regulates the expression of circular RNAs (circRNAs), microRNAs (miRNAs) and mRNAs. OBJECTIVE: The aim of this study was to examine the expression of circRNAs, miRNAs and mRNAs exposed to OS. METHODS: Piglets were exposed to diquat (DQ), a herbicide, and the activity of antioxidant enzymes and the morphology of the intestine were investigated. We utilized whole transcriptome sequencing to examine the global expression of circRNAs, miRNAs and mRNAs in the jejunum. RESULTS: Compared to controls, 751 circRNAs, 731 miRNAs and 164 mRNAs were differentially expressed in diquat-treated piglets. Kyoto Encyclopedia of Genes and Genomes pathway analysis indicated that oxidative phosphorylation, RNA degradation and ubiquitin-mediated proteolysis were closely associated with OS. CONCLUSIONS: Our results indicated that diquat-induced OS alters the intestinal structure, resulting in the differential expression of circRNAs, miRNAs and mRNAs in the jejunum of piglets. Meanwhile, OS weakened the enzyme antioxidant system in serum of piglets. Our results provide a foundation for further studies on the mechanisms involved in the response to OS in the jejunum.

Chaperon-mediated autophagy can regulate diquat-induced apoptosis by inhibiting α-synuclein accumulation cooperatively with macroautophagy.

α-Synuclein, which is associated with Parkinson's disease, is cleared by the ubiquitin-proteasome system and autophagy lysosome system. Chaperon-mediated autophagy (CMA) and macroautophagy are major subtypes of autophagy and play a critical role in pesticide-induced α-synucleinopathy. In this study, we explored the role of CMA in diquat (DQ)-induced α-synucleinopathy and characterized the relationship between CMA and macroautophagy in the clearance of pathologic α-synuclein for the prevention of DQ neurotoxicity. DQ was cytotoxic to SH-SY5Y cells in a concentration-dependent manner, as shown by decreased cell viability and increased cytotoxicity. DQ treatment was also found to induce autophagy such as CMA and macroautophagy by monitoring the expression of Lamp2A and microtubule-associated protein 1A/1B light chain 3B (LC3-II) respectively. Following DQ treatment, SH-SY5Y cells were found to have induced phosphorylated and detergent-insoluble α-synuclein deposits, and MG132, a proteasome inhibitor, effectively potentiated both CMA and macroautophagy for preventing α-synuclein aggregation. Interestingly, CMA impairment by Lamp2A-knock down decreased the LC3II expression compared to in DQ-treated cells transfected with control siRNA. In Lamp2-knock down cells, pathologic α-synuclein was increased 12 h after DQ treatment, but there was no change observed at 24 h. In DQ-treated cells, macroautophagy by 3-methyladenine and bafilomycin inhibition increased Lamp2A expression, indicating an increase in CMA activity. In addition, CMA modulation affected apoptosis, and inhibiting lysosome activity by NH4Cl increased apoptosis in DQ-treated cells. An increase in autophagy was confirmed to compensate for the decrease in lysosome activity. Pretreatment with z-VAD-fmk, a pan-caspase inhibitor, significantly enhanced the macroautophagy response of DQ-exposed cells without alterations in Lamp2A expression. Our results suggest that CMA can regulate DQ-induced α-synucleinopathy cooperatively with macroautophagy, and crosstalk between macroautophagy and CMA plays an important role in DQ-induced cytotoxicity. Taken together, autophagy modulation may be a useful treatment strategy in pesticide-induced neurodegenerative disorders through preventing α-synucleinopathy.

Vitamin D3 Protects Mice from Diquat-Induced Oxidative Stress through the NF-κB/Nrf2/HO-1 Signaling Pathway.

Vitamin D3, as an indispensable and fat-soluble micronutrient, plays an important role in the health of humans and animals. At present, studies are focusing on the calcium absorption and immunoregulation function of vitamin D3; this study was aimed at exploring the antioxidative stress ability of vitamin D3 on diquat-induced intestinal dysfunction of ICR mice and the underlying mechanism. The results showed that oral gavage of vitamin D3 daily significantly improved the body weight gain and immune organ index and significantly reverted the abnormal changes of ALT, AST, SOD, GSH-Px, T-AOC, and MDA in the serum and jejunum induced by diquat. The addition of vitamin D3 also significantly reduced the concentration of DAO, D-LA, and certain proinflammatory cytokines in serum. Moreover, vitamin D3 improved the pathological morphology of the duodenum, jejunum, colon, liver, and kidney tissues, and it also largely attenuated the degree of inflammatory infiltration of macrophages and cell apoptotic index of jejunal epithelial tissue induced by diquat. The results demonstrated that vitamin D3 significantly recovered the intestinal barrier injury by enhancing the expression of mucins and tight junction proteins in the jejunum. In addition, the results indicated that vitamin D3 could significantly reduce the phosphorylation level of NF-κB (p65) and enhance the expression of Nrf2 and HO-1 in the jejunum compared with the diquat-induced group. This study suggested that oral administration of vitamin D3 can protect mice against oxidative damage by inhibiting the phosphorylation level of NF-κB (p65) and activating Nrf2-related signaling pathways.

Kaempferol attenuates diquat-induced oxidative damage and apoptosis in intestinal porcine epithelial cells.

Kaempferol, a flavonol component of plants, is well-known to exhibit multiple bioactivities, such as anti-oxidative and anti-apoptotic effects. However, the underlying mechanisms responsible for the beneficial effects remain elusive. This study was conducted to test the hypothesis that kaempferol attenuated diquat-induced oxidative damage and intestinal barrier dysfunction by ameliorating oxidative damage and apoptosis in intestinal porcine epithelial cells. Compared with the control group, diquat treatment led to enhanced intracellular ROS production, increased mitochondrial depolarization, and apoptosis, which were accompanied by cell cycle arrest at the G1 phase, reduced cell migration, and disrupted intestinal epithelial barrier function. These effects triggered by diquat were reversed by kaempferol. Further study showed that the protective effect of kaempferol was associated with an enhanced mRNA level of genes related to cell cycle progression (cyclin D1, CDK4, and E2F1) and genes implicated in the anti-oxidant system (GSR, GSTA4, and HO-1), up-regulated abundance of tight junctions (ZO-1, ZO-2, occludin, and claudin-4), as well as enhanced Nrf2, an anti-oxidant transcription factor. In conclusion, we revealed a functional role of kaempferol in the intestinal barrier. Ingestion of kaempferol-rich foods might be a potential strategy to improve the integrity and function of enterocytes.

Mortalidade de abelhas sem ferrão Scaptotrigona bipunctata sob os efeitos dos herbicidas paraquat e diquat / Mortality of Scaptotrigona bipunctata stingless bees under the effects of paraquat and diquat herbicides / Mortalidad de abejas sin aguijón Scaptotrigona bipunctata bajo los efectos de los herbicidas paraquat y diquat

As abelhas exercem essencial atividade polinizadora, além de fundamentais na manutenção ecossistêmica, também polinizam diversos sistemas agrícolas. São crescentes os relatos sobre o desaparecimento de abelhas, possivelmente em decorrência do intenso uso de agrotóxicos, os quais não possuem seus efeitos sobre a biodiversidade, de fato, conhecidos. A maioria dos estudos nessa área é voltada para a compreensão dos efeitos de inseticidas, porém, os herbicidas também podem influenciar na mortandade dos insetos polinizadores. Referente aos herbicidas paraquat e diquat, amplamente utilizados na agricultura, pouco se conhece sobre os efeitos que atingem organismos não-alvo, como as abelhas. Este trabalho avaliou a mortalidade das abelhas Scaptotrigona bipunctata submetidas aos herbicidas paraquat e diquat, via contato e ingestão. Dois experimentos foram conduzidos no delineamento de blocos casualizados em esquema fatorial 2 x 2 com tratamento adicional, em três repetições. Os tratamentos foram: dois herbicidas (paraquat e diquat), duas doses (50 e 100%) e um tratamento adicional sem exposição ao produto (controle). Cada parcela consistiu em dez indivíduos, expostos aos tratamentos e incubados à 28oC durante 72 horas em ambiente controlado. Para o experimento de ingestão, ambas as doses dos herbicidas resultaram em maior mortalidade de abelhas em relação à condição controle. Ademais, a dose 100% resultou em maior toxicidade comparada à dose 50%. Para a contaminação via contato, não houve aumento na mortalidade das abelhas perante a exposição. Conclui-se que a contaminação por ingestão com os herbicidas paraquat e diquat pode afetar a sobrevivência das abelhas sem ferrão, podendo em longo prazo alterar a viabilidade e a dinâmica das populações das abelhas Scaptotrigona bipunctata.(AU)

Bees have essential pollinating activities and are fundamental to the maintenance of the ecosystem since they also pollinate various agricultural systems. There are growing reports about the disappearance of bees, possibly due to the intense use of pesticides, which do not have their effects on biodiversity fully known. Most studies in this area are aimed at understanding the effects of insecticides; however, herbicides can also influence the mortality of pollinating insects. Regarding the paraquat and diquat herbicides, widely used in agriculture, little is known about the effects on non-target organisms, such as bees. This work evaluated the mortality of Scaptotrigona bipunctata bees submitted to the paraquat and diquat herbicides via contact and ingestion. Two experiments were conducted in a randomized block design in a 2 x 2 factorial scheme with additional treatment, in three replications. The treatments were: two herbicides (paraquat and diquat), two doses (50 and 100%), and an additional treatment without contamination (control). Each plot consisted of ten individuals exposed to treatments and incubated at 28 ºC for 72 hours in a controlled environment. For the ingestion experiment, both doses of the herbicides resulted in higher bee mortality when compared to the control condition. In addition, the 100% dose resulted in greater toxicity when compared to the 50% dose. For contact contamination, there was no increase in bee mortality on exposure. It can be concluded that contamination by ingestion of paraquat and diquat can affect the survival of stingless bees, which in the long term may alter the viability and population dynamics of Scaptotrigona bipunctata bees.(AU)

Las abejas ejercen una actividad polinizadora esencial, además de ser fundamentales en el mantenimiento de los ecosistemas, también polinizan varios sistemas agrícolas. Cada vez hay más informes sobre la desaparición de abejas, posiblemente como consecuencia del uso intenso de pesticidas, que no tienen sus efectos sobre la biodiversidad, de hecho, conocidos. La mayoría de los estudios en esta área tienen como objetivo comprender los efectos de los insecticidas, sin embargo, los herbicidas también pueden influir en la mortalidad de los insectos polinizadores. Con respecto a los herbicidas paraquat e diquat, ampliamente utilizados en la agricultura, se sabe poco sobre los efectos que afectan a organismos no objetivo, como las abejas. Esta investigación evaluó la mortalidad de abejas Scaptotrigona bipunctata sometidas a herbicidas paraquat y diquat, por contacto e ingestión. Dos experimentos fueron conducidos en el delineamiento de bloques casualizados en esquema factorial 2 x 2 con tratamiento adicional, en tres repeticiones. Los tratamientos fueron: dos herbicidas (paraquat y diquat) dos dosis (50 y 100%) y un tratamiento adicional sin exposición al producto (control). Cada parcela estuvo compuesta por diez individuos, expuestos a tratamientos e incubados a 28ºC durante 72 horas en ambiente controlado. Para el experimento de ingestión, ambas dosis de herbicidas resultaron en mayor mortalidad de abejas en comparación con la condición de control. Además, la dosis del 100% resultó en mayor toxicidad en comparación con la dosis del 50%. Para la contaminación por contacto, no hubo un aumento en la mortalidad de las abejas debido a la exposición. Se concluye que la contaminación por ingestión con herbicidas paraquat y diquat puede afectar la supervivencia de las abejas sin aguijón, lo que a largo plazo puede alterar la viabilidad y la dinámica poblacional de las abejas Scaptotrigona bipunctata.(AU)

In vivo toxicological assessment of diquat dibromide: cytotoxic, genotoxic, and biochemical approach.

Diquat dibromide is a comprehensive herbicide commonly used in the cultivation of cotton, soybeans, and other crops to combat unwanted weeds. In this study, the half-maximal effective concentration (EC50) value of diquat dibromide was determined 60 mg/L in the Allium root growth inhibition test. ½ × EC50 (30 mg/L), EC50 (60 mg/L), and 2 × EC50 (120 mg/L) concentrations of diquat dibromide were applied to Allium cepa L. bulbs for 72 h to investigate the dose-dependent toxic effects. To determine the toxic effects cytogenetic, biochemical and physiological parameters were used. Physiological effects were investigated by determination of the percentage of rooting, relative injury rate, root length, and weight gain. Genetic effects were evaluated by the frequency of chromosomal abnormalities (CAs), micronucleus (MN) formation, mitotic index (MI) rate, and comet assay. Biochemical parameters were evaluated with antioxidant enzyme activities and lipid peroxidation by determining malondialdehyde (MDA) level, superoxide dismutase (SOD) activity, catalase (CAT) activity, and glutathione (GSH) level. Also, chlorophyll pigment contents (a, b, and total) in green leaves were calculated to elucidate the effect of diquat dibromide on plants and the biosphere. The findings show that increasing doses of diquat dibromide caused a decrease in all physiological parameters and MI ratio, promoting MN and CAs and tail DNA formation in genetic parameters. It was determined by the increases in MDA level, SOD, and CAT activities and decreases in GSH levels that diquat dibromide administration caused oxidative stress depending on the dose. Also, chlorophyll pigment levels (a, b, and total) measured in leaf tissues decreased with the application dose. Considering that the toxic effects caused by diquat dibromide and that organisms other than unwanted plants will be exposed during the application, its use should be abandoned and biocontrol methods should be used instead. In cases where use is compulsory, doses that will not harm the environment and organisms should be determined and used.

Dietary squalene supplementation alleviates diquat-induced oxidative stress and liver damage of broiler chickens.

The aim of this study was to explore the protective effects of squalene supplementation on growth performance, oxidative status, and liver function of diquat-challenged broilers. One hundred forty-four 1-day-old male Ross 308 broiler chicks were allocated to 3 groups, and each group consisted of 6 replicates of 8 birds each. The three groups were as follows: 1) nonchallenged broilers fed with a basal diet (control group), 2) diquat-challenged broilers fed a basal diet, and 3) diquat-challenged broilers fed with a basal diet supplemented with 1.0 g/kg of squalene. Broilers were intraperitoneally injected with 20 mg/mL of diquat solution at a dosage of 1 mL/kg of BW or an equivalent amount of saline at 20 d. Compared with the control group, weight gain and BW change rate during 24 h after injection were decreased by diquat challenge (P < 0.05), and the diquat-induced compromised growth performance was improved by squalene supplementation (P < 0.05). Diquat administration reduced plasma superoxide dismutase activity and increased malondialdehyde accumulation and glutathione peroxidase activity in both plasma and the liver (P < 0.05). In contrast, plasma glutathione peroxidase activity in diquat-challenged broilers was reduced by squalene supplementation (P < 0.05). The hepatic glutathione level was reduced by diquat administration (P < 0.05), whereas its level in plasma and the liver of diquat-challenged broilers was increased by squalene supplementation (P < 0.05). The relative liver weight of broilers was increased by diquat challenge (P < 0.05), with its value being intermediate in the squalene-supplemented group (P > 0.05). The plasma aminotransferase activities and total bilirubin concentration were increased by diquat challenge (P < 0.05), which were reduced by squalene supplementation (P < 0.05). The mRNA abundance of hepatic nuclear factor erythroid 2-related factor 2 (P < 0.05) was upregulated by diquat treatment, regardless of squalene supplementation. The mRNA abundance of hepatic glutathione peroxidase 1 and B-cell lymphoma/leukemia 2-associated X protein was upregulated by diquat challenge (P < 0.05), which was reversed by squalene administration (P < 0.05). Squalene increased NAD(P)H quinone dehydrogenase 1 mRNA abundance and decreased caspase 3 mRNA abundance in the liver of diquat-challenged broilers (P < 0.05). The results suggested that squalene can increase weight gain, improve oxidative status, and alleviate liver injury in diquat-challenged broilers.