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

Curcumin alleviates cecal oxidative injury in diquat-induced broilers by regulating the Nrf2/ARE pathway and microflora

This study evaluated the alleviative effect of curcumin (CUR) on the diquat (DQ)-induced cecal injury in broilers. A total of 320 one-day-old Cobb broilers were selected and randomly divided into 4 treatments, namely control, DQ, CUR 100, and CUR150 groups. The control and DQ groups were fed a basal diet, while the CUR 100 and CUR150 groups were fed the basal diet supplemented with 100 and 150 mg/kg CUR, respectively. Each group had 8 replicates, with 10 broilers per replicate. On day 21 of the experiment, 1 broiler was selected from each replicate and intraperitoneally injected 20 mg/kg body weight of DQ for DQ, CUR 100, and CUR 150 groups. Broilers in control group received equivalent volume of saline. Broilers were euthanized 48h postinjection for tissue sampling. The results showed that DQ injection could cause oxidative stress and inflammatory reactions in the cecum, affecting the fatty acid production and flora structure, thus leading to cecum damage. Compared with the DQ group, the activity of superoxide dismutase, the level of interleukin 10, acetic acid, and total volatile fatty, and the abundance of nuclear factor E2-related factor 2, copper and zinc superoxide dismutase and catalase mRNA in the cecal mucosa of broilers in the CUR group increased significantly (P < 0.05). However, the levels of malondialdehyd, reactive oxygen species, tumor necrosis factor-alpha, and the expression of cysteine-aspartic acid protease-3 and tumor necrosis factor-alpha decreased significantly (P < 0.05) in the CUR group. In addition, CUR treatment alleviated the damage to the cecum and restored the flora structure, and Lactobacillus and Lactobacillaceae promoted the alleviative effect of CUR on DQ. In summary, CUR could alleviate the cecal injury caused by DQ-induced oxidative damage and inflammatory reactions by regulating the Nrf2-ARE signaling pathway and intestinal flora, thus protecting the cecum.

Elucidating the mechanisms underlying astrocyte-microglia crosstalk in hippocampal neuroinflammation induced by acute diquat exposure

The transition from paraquat (PQ) to diquat (DQ), both organic dication herbicides, in China has led to significant increases in the number of acute DQ poisoning cases. Case studies have shown that acute DQ poisoning resulted in injury to the central nervous system (CNS), but the mechanism underlying the injury remains to be explored. The present study aimed to investigate how DQ influenced purinergic signaling between astrocytes and microglia and whether extracellular ATP (eATP) was involved in promoting neuroinflammation induced by acute DQ toxicity through the activation of the P2X4/NLRP3 signaling pathway. We constructed a rat model of acute DQ toxicity to observe the pathological changes in hippocampal tissues after DQ exposure and measure the expression levels of IL-1β and TNF-α in the hippocampal tissue. We also established an in vitro co-culture model of C6 astrocytes and BV-2 microglia using transwell chambers, measured the amount of eATP secreted into C6 astrocytes after DQ treatment, and assessed the inflammatory response and changes in the P2X4/NLRP3 signaling pathway in BV-2 microglia. The results showed that the neurons in the hippocampal tissue of rats exhibited loose arrangement, nuclear consolidation, and necrosis after DQ exposure, and IL-1β and TNF-α levels were signification higher in the hippocampal tissue after DQ exposure. DQ exposure to the co-cultured cells induced an increase in ATP secretion from C6 astrocytes as well as a significant increase of P2X4, NLRP3, IL-1β, and IL-18 expression in BV-2 microglia. In contrast, pretreatment of C6 astrocytes with apyrase (an ATP hydrolase) resulted in a significant decrease of P2X4, NLRP3, IL-1β, and IL-18 expression in BV-2 microglia. Furthermore, inhibition of P2X4 expression in BV-2 microglia by transfection with si-P2X4 effectively reversed the increase of NLRP3, IL-1β, and IL-18 in BV-2 microglia induced by DQ when co-cultured with C6 astrocytes. These results indicate that astrocytes can activate the P2X4/NLRP3 signaling pathway in microglia through the DQ-induced extracellular release of ATP to promote neuroinflammation in rat hippocampal tissue.

The physiological function of squalene and its application prospects in animal husbandry

Squalene, which is a natural triterpenoid unsaturated hydrocarbon, is abundant in shark liver and plant seeds. Squalene has various physiological functions such as being anti-inflammatory and antioxidant. This paper reviews the physiological functions of squalene and its application prospects in livestock and poultry production, with a view to providing a theoretical basis for its in-depth application in animal husbandry.

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.

Plant-derived squalene supplementation improves growth performance and alleviates acute oxidative stress-induced growth retardation and intestinal damage in piglets

Piglets are particularly susceptible to oxidative stress, which causes inferior growth performance and intestinal damage. Squalene (SQ), a natural bioactive substance enriched in shark liver oil, shows excellent antioxidant properties and can currently be obtained at a low cost from deodorizer distillate during the production of plant oil. This study aimed to evaluate the effects of plant-derived SQ supplementation on the growth performance of piglets and explore the beneficial roles of SQ against oxidative stress and intestinal injury in diquat-challenged piglets. Forty piglets were randomly divided into five groups and fed a basal diet supplemented with SQ at 0, 500, 1000, or 2000 mg/kg for 5 weeks. Acute oxidative stress was induced in the piglets with diquat (10 mg/kg BW) at the fourth week of the experiment, followed by a 7-d recovery period. Results showed that before the diquat challenge, SQ supplementation significantly improved growth performance (average daily gain and feed conversion ratio) and serum antioxidant status, and after the diquat challenge, SQ supplementation significantly mitigated diquat-induced growth arrest, intestinal villous atrophy, intestinal epithelial cell apoptosis, intestinal hyperpermeability, and deficiency of intestinal epithelial tight junction proteins (zonula occludens-1, occludin, and claudin-3). Under oxidative stress induced by diquat, SQ supplementation consistently improved the antioxidant status of the small intestine, liver, and muscle. In vitro, SQ was shown to alleviate hydrogen peroxide (H2O2)-induced increase of the levels of intracellular reactive oxygen species and apoptosis of porcine intestinal epithelial cells. Taken together, SQ supplementation improves growth performance and effectively alleviates acute oxidative stress-induced growth retardation and intestinal injury via improving antioxidant capacity in piglets. Our findings may provide an efficient strategy for alleviating oxidative stress-induced inferior growth performance and intestinal damage in piglets.

Squalene Supplementation as a Novel to Increase PUFA Content in Fish Tissues

Squalene is an antioxidant that plays an essential role in fat metabolism. The study aimed to assess the effect of squalene supplied in feed on the growth performance, health status, and fatty acid profiles of muscle and liver of Siberian sturgeon, rainbow trout, and Eurasian perch. The experimental feeds containing 0%, 0.5%, and 1.0% squalene were prepared for each fish species. Hematological and biochemical indices, liver histology, and fatty acid profiling of muscle and liver were analyzed. Squalene supplementation was safe for fish, and no negative influence on growth status was observed. However, changes in the values of hematological and biochemical indicators were found, including the level of triglycerides in the blood of rainbow trout, and cholesterol in the blood of Eurasian perch. The addition of squalene influences the nucleocytoplasmic index values in all fish offered feed containing 1% squalene. The retention of squalene in the liver and muscle of experimental Siberian sturgeon was observed in both 0.5% and 1.0% squalene levels of feed. The PUFA and docosahexaenoic acid increase was observed in all fish in groups with squalene addition. Dietary squalene increases the content of PUFAs in tissues of the examined species.

Liver Protection of a Low-Polarity Fraction from Ficus pandurata Hance, Prepared by Supercritical CO2 Fluid Extraction, on CCl4-Induced Acute Liver Injury in Mice via Inhibiting Apoptosis and Ferroptosis Mediated by Strengthened Antioxidation

Ficus pandurata Hance (FPH) is a Chinese herbal medicine widely used for health care. This study was designed to investigate the alleviation efficacy of the low-polarity ingredients of FPH (FPHLP), prepared by supercritical CO₂ fluid extraction technology, against CCl₄-induced acute liver injury (ALI) in mice and uncover its underlying mechanism. The results showed that FPHLP had a good antioxidative effect determined by the DPPH free radical scavenging activity test and T-AOC assay. The in vivo study showed that FPHLP dose-dependently protected against liver damage via detection of ALT, AST, and LDH levels and changes in liver histopathology. The antioxidative stress properties of FPHLP suppressed ALI by increasing levels of GSH, Nrf2, HO-1, and Trx-1 and reducing levels of ROS and MDA and the expression of Keap1. FPHLP significantly reduced the level of Fe²⁺ and expression of TfR1, xCT/SLC7A11, and Bcl2, while increasing the expression of GPX4, FTH1, cleaved PARP, Bax, and cleaved caspase 3. The results demonstrated that FPHLP protected mouse liver from injury induced by CCl₄ via suppression of apoptosis and ferroptosis. This study suggests that FPHLP can be used for liver damage protection in humans, which strongly supports its traditional use as a herbal medicine.

Effects of the Vitamin D3 on Alleviating the Oxidative Stress Induced by Diquat in Wenchang Chickens

Vitamin D₃ (VD₃) is an indispensable micronutrient in livestock and poultry feed. Its function in antioxidant stress has been reported. We investigate whether the addition of different concentrations of VD₃ to the diet affects the production performance, slaughter performance, meat quality, organ index, and gut injury on the diquat (DQ)-induced model of oxidative stress in Wenchang chickens. Four hundred and eighty one-day-old chickens were randomly divided into six groups: control (basal diet), 4000 VD (basal diet + VD₃ 4000 IU per kg feed intake), 1000 VD+DI (DQ, basal diet + VD₃ 1000 IU per kg feed intake), 2000 VD+DI (DQ, basal diet + VD₃ 2000 IU per kg feed intake), and 4000 VD+DI (DQ, basal diet + VD₃ 4000 IU per kg feed intake). The results showed that the addition of VD₃ to the diet promoted DQ-induced weight loss and reduced ADFI, slaughter rate, splenic index, and pH after 1 h and 24 h in the leg muscles. VD₃ decreased the increase in content of interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) among proinflammatory cytokines (p < 0.05) and increased the reduction in anti-inflammatory cytokines content of interleukin-10 (IL-10) (p < 0.05) induced by DQ. In addition, liver and kidney injury biomarkers and the intestinal permeability index in serum were disordered after treatment with DQ (p < 0.05). VD₃ perfected the increase of D-lactic acid (D-LA), diamine oxidase (DAO), total cholesterol (T-CHO), creatinine (CR), blood urea nitrogen (BUN), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C) content, aspartate transaminase (AST), alanine transaminase (ALT), and lactate dehydrogenase (LDH) activity (p < 0.05); it increased the decrease of albumin (ALB) content (p < 0.05). Meanwhile, VD₃ regulated the intestinal morphology and intestinal barrier. Moreover, DQ induced a decrease in total antioxidant capacity and antioxidant enzyme activity in the serum, liver, and jejunum (p < 0.05), and an increase in malonaldehyde (MDA) content (p < 0.05). However, the addition of different levels of VD₃ could alleviate the above phenomenon of oxidative stress in Wenchang chickens to different degrees. Thus, this research suggested that the addition of VD₃ can relieve the DQ-induced oxidative stress of Wenchang chickens, and the level of VD₃ acquisition is positively correlated with the remission effect.

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.

Screening and Characterization of Pediococcus acidilactici LC-9-1 toward Selection as a Potential Probiotic for Poultry with Antibacterial and Antioxidative Properties

Growing interest has been focused on lactic acid bacteria as alternatives to antimicrobial growth promoters, which are characterized by the production of various functional metabolites, such as antimicrobial and antioxidants compounds. The present study was undertaken to evaluate a potential probiotic from the antioxidant perspective. LC-9-1, screened from the intestines of healthy animals, was revealed to be Pediococcus acidilactici on the basis of its morphological, biochemical, and molecular characteristics. The strain has excellent properties, including acid-production efficiency, antibacterial performance and antioxidant activity. The safety of the strain was also evaluated. Furthermore, the experiments in broiler chickens suggested that dietary LC-9-1 supplementation improved the growth performance and decreased the abdominal fat, and enhanced the antioxidant capability and intestinal innate immunity of broilers. Analysis of intestinal microbiota showed that a higher community diversity (Shannon index) was achieved. In addition to the significantly increased relative abundances of Pediococcus spp., beneficial genera such as Rothia spp. and Ruminococcus spp. were abundant, while opportunistic pathogens such as Escherichia-Shigella spp. were significantly reduced in LC-9-1-supplemented broilers. Collectively, such in-depth characterization and the available data will guide future efforts to develop next-generation probiotics, and LC-9-1 could be considered a potential strain for further utilization in direct-fed microbial or starter culture for fermentation.

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-1β, tumor necrosis factor-α, and interleukin-6 levels (P < 0.05), and the values of interleukin-1β 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.

Magnolol supplementation alleviates diquat-induced oxidative stress via PI3K-Akt in broiler chickens

This experiment was conducted to investigate the effects of magnolol on the oxidative parameters and jejunum injury induced by diquat in broiler chickens. This test adopts a 2 × 2 factors design, a total of 288 one-day-old male AA broiler chicks randomly allocated to four groups, consisting of six replicates of 12 birds each, which was then denoted as CON group, diquat (DIQ) group (16 mg/kg BW diquat was injected into birds at the age of 21 days), magnolol (MAG) group (basic bird diet supplemented with 300 mg/kg magnolol), and MAG + DIQ group. At 21 days of age, broilers in the DIQ group and the MAG + DIQ group were intraperitoneally injected with 16 mg/kg BW diquat. Results showed that diet supplementing with MAG could alleviate the decrease of ADG to a certain extent after exposure to DIQ. Addition of magnolol to the diet alleviated the decrease of ADG during injection, antioxidant enzymes, and gene expression and increased the markers of oxidative damage induced by diquat induction. Magnolol supplement reversed the increase of apoptotic cells in the diquat-induced chicken jejunum. RNA sequencing showed that PI3K-Akt, calcium, and NF-kappa B signaling pathways were the main enrichment pathways between the DIQ group and the MAG + DIQ group. Our findings revealed that magnolol may improve antioxidant enzyme activity and expression of related genes through the PI3K-Akt pathway to alleviate oxidative stress.

Dietary supplementation of squalene increases the growth performance of early-weaned piglets by improving gut microbiota, intestinal barrier, and blood antioxidant capacity

This study aimed to investigate the effects of dietary squalene (SQ) supplementation on the growth performance of early-weaned piglets. Twenty early-weaned piglets were randomly divided into two groups, the squalene group (SQ) and the control group (CON). The CON group was fed a basal diet, and the SQ group was fed a basal diet with 250 mg/kg squalene. The feeding period lasted 21 days. The results showed that SQ significantly increased the final body weight (FWB, P < 0.05), average daily gain (ADG, P < 0.05), and average daily feed intake (ADFI, P < 0.05) and significantly decreased the F/G ratio (feed intake/gain, P < 0.05) and diarrhea index (DI, P < 0.05). In terms of blood biochemical indicators, SQ significantly increased anti-inflammatory factors such as transforming growth factor-β (TGF-β, P < 0.001), interleukin-10 (IL-10, P < 0.001), and interferon-γ (IFN-γ, P < 0.01), and decreased pro-inflammatory factors such as tumor necrosis factor-α (TFN-α, P < 0.001) and interleukin-6 (IL-6, P < 0.001). Furthermore, SQ significantly increased blood antioxidant indexes (P < 0.001) such as superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), and total antioxidant capacity (T-AOC) and significantly decreased the level of malondialdehyde (MDA) (P < 0.001). The villus height (P < 0.001) and V/C ratio (villus height/crypt depth, P < 0.001) of the jejunum were significantly increased in the SQ group, while the crypt depth (P < 0.01) was decreased compared to the CON group. The intestinal permeability indexes, namely diamine oxidase (DAO), D-lactic acid (D-Lac), regenerative insulin-derived protein 3 (REG-3), and FITC-Dextran 4 (FD₄), significantly decreased the concentrations in the treatment group (P < 0.001), and the antioxidant indexes of the jejunum, such as SOD, GSH-Px, CAT, and MDA, were improved by adding SQ. The qPCR results showed that adding SQ could significantly increase the mRNA expression of jejunal tight-junction proteins, such as zonula occludens-1 (ZO-1, P < 0.001), Occludin (P < 0.001), Claudin (P < 0.001), glucagon-like peptide-2 (GLP-2, P < 0.001), and insulin-like growth factor-1 (IGF-1, P < 0.001). Then, we used Western blotting experiments to further confirm the qPCR results. In addition, it was found that adding SQ increased the abundance of beneficial bacteria such as Gemmiger (P < 0.01) and decreased the abundance of harmful bacteria such as Alloprevotella (P < 0.05), Desulfovibrio (P < 0.05), and Barnesiella (P < 0.05). It was interesting that there was a very close correlation among the fecal microbes, growth performance parameters, intestinal barrier, and blood biochemical indicators. In conclusion, the data suggest that SQ supplementation could effectively improve the growth performance of early-weaned piglets by improving the gut microbiota, intestinal barrier, and antioxidant capacity of the blood and jejunal mucosa.

Chronic heat stress causes liver damage via endoplasmic reticulum stress-induced apoptosis in broilers

Liver is a central metabolic organ, which is sensitive to heat stress. Liver damage affects animals' health and endangers the livestock and poultry industry. This study aimed to investigate the mechanism of chronic heat stress-induced liver damage in broiler chickens. Broilers were divided into 3 treatments: normal control group (NOR, 22°C), heat stress group (HS, 32°C) and pair-feeding group (PF, 22°C) for a 7-d and 14-d trial. The results showed that 7 d heat exposure caused microvesicular steatosis and reduced glutamine synthetase activity in broiler liver (P < 0.05). After 14 d of heat exposure, heat stress caused vacuolar degeneration and apoptosis in the liver; elevated liver relative weight and liver glutaminase activity as well as plasma ammonia level (P < 0.05). Additionally, heat stress enhanced GRP78 protein expression and the mRNA expressions of endoplasmic reticulum (ER) stress responses genes and apoptosis-related genes in broiler liver after 14 d of heat exposure (P < 0.05). In conclusion, chronic heat stress triggered ER stress-induced apoptosis and caused liver damage, which may compromise ammonia detoxification in broiler liver.

Effects of Dietary L-Theanine on Growth Performance, Antioxidation, Meat Quality, and Intestinal Microflora in White Feather Broilers With Acute Oxidative Stress

In order to reduce the negative effects caused by oxidative stress on broilers, it is particularly important to find ways to alleviate oxidative stress. As a natural plant extract, L-theanine has a variety of biological effects, such as improving antioxidant capacity, promoting growth, and enhancing immunity and antitumor. This trial evaluated the effects of dietary supplementation of L-theanine on growth performance, antioxidation, meat quality, and intestinal microflora in 817 White Feather Broilers. A total of 108 21-day-old 817 broilers with similar body weight (BW) were randomly divided into three groups with six replicates per group and six chickens within each replicate. The three groups were corn-soybean-based diet (NC group); basal diet plus drinking water with 30 mg hydrocortisone/kg (PC group); and basal diet supplemented with 400 mg L-theanine/kg plus drinking water with 30 mg hydrocortisone/kg (LT group). Compared with the NC group, from 21 to 24 days of age, the PC and LT groups had decreased BW, average daily gain (ADG), and average daily feed intake (ADFI), and increased feed to gain ratio (F/G; p < 0.05). At 24 days of age, the LT group had improved superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in serum as compared to the NC group (p < 0.05). The LT group broilers also had significantly higher concentrations of malondialdehyde (MDA) in serum and liver (p < 0.05). On the 42nd days, the PC group had lower PH_45min (p < 0.05) than the NC and LT groups and higher cooking loss and shear force (p < 0.05). Moreover, the villi height of the PC group was significantly lower in jejunum than the NC group (p < 0.05). The LT group had a higher ZO-1 content in duodenum than the NC and PC groups (p < 0.05). The activity of GSH-Px in the liver of the LT group was increased than in the PC group (p < 0.05). The relative abundance of Firmicutes in the LT group was significantly higher than in the NC and PC groups (p < 0.05). These results suggested that the effects of acute oxidative stress on growth performance and meat quality of broilers are continuous, and dietary supplementation of L-theanine could improve the growth performance and meat quality, enhance the intestinal mucosal barrier and antioxidant capacity, and improve the composition of the intestinal flora of broilers caused by acute oxidative stress.

Protective Effects of Resveratrol and Apigenin Dietary Supplementation on Serum Antioxidative Parameters and mRNAs Expression in the Small Intestines of Diquat-Challenged Pullets

Poultry as a large-scale intensive farming is vulnerable to oxidative stress. Resveratrol and apigenin are recognized to have many beneficial bioactive functions. This study tested the hypothesis that dietary resveratrol and apigenin supplementation alleviates oxidative stress in the small intestine of diquat-challenged pullets. A total of 200 healthy pullets were randomly divided into four treatment groups: control group fed with a basal diet (CON), diquat group fed with a basal diet (DIQ), resveratrol group fed with a basal diet containing 500 mg/kg resveratrol (RES), and an apigenin group fed with a basal diet containing 500 mg/kg apigenin (API) and injected intraperitoneally with either 1 ml of saline (CON) or 8 mg/kg body weight of diquat (DIQ, RES, and API) to induce oxidative stress. The day of the injection was considered as day 0. The results indicated that resveratrol and apigenin were able to decrease the malondialdehyde (MDA) level and upregulate total antioxidant capacity (T-AOC), superoxide dismutase (SOD), and glutathione peroxidase (GSH-PX) levels in serum on day 1 and 10 after being diquat-challenged. In addition, resveratrol increased mRNA expression of NQO1 (NAD(P)H dehydrogenase quinone 1) and HO-1 (heme oxygenase-1) in ileum and jejunum on day 10, while apigenin upregulated nuclear factor erythroid 2-related factor 2 (NRF2), NQO1, and HO-1 in ileum and jejunum on day 10. Both resveratrol and apigenin increased the mRNA expression of CLAUDIN-1 in ileum and jejunum on day 1 and that of ZO-1 (zonula occludens-1) in ileum on day 10 post-diquat-injection. These findings indicate that dietary supplementation with resveratrol and apigenin attenuates oxidative stress involving NRF2 signaling pathways in diquat-challenged pullets to some extent. These observations are valuable for the chicken industry and resveratrol and apigenin applications in animal husbandry.

Squalene Loaded Nanoparticles Effectively Protect Hepatic AML12 Cell Lines against Oxidative and Endoplasmic Reticulum Stress in a TXNDC5-Dependent Way

Virgin olive oil, the main source of fat in the Mediterranean diet, contains a substantial amount of squalene which possesses natural antioxidant properties. Due to its highly hydrophobic nature, its bioavailability is reduced. In order to increase its delivery and potentiate its actions, squalene has been loaded into PLGA nanoparticles (NPs). The characterization of the resulting nanoparticles was assessed by electron microscopy, dynamic light scattering, zeta potential and high-performance liquid chromatography. Reactive oxygen species (ROS) generation and cell viability assays were carried out in AML12 (alpha mouse liver cell line) and a TXNDC5-deficient AML12 cell line (KO), which was generated by CRISPR/cas9 technology. According to the results, squalene was successfully encapsulated in PLGA NPs, and had rapid and efficient cellular uptake at 30 µM squalene concentration. Squalene reduced ROS in AML12, whereas ROS levels increased in KO cells and improved cell viability in both when subjected to oxidative stress by significant induction of Gpx4. Squalene enhanced cell viability in ER-induced stress by decreasing Ern1 or Eif2ak3 expressions. In conclusion, TXNDC5 shows a crucial role in regulating ER-induced stress through different signaling pathways, and squalene protects mouse hepatocytes from oxidative and endoplasmic reticulum stresses by several molecular mechanisms depending on TXNDC5.

Effects of dietary supplementation with itaconic acid on the growth performance, nutrient digestibility, slaughter variables, blood biochemical parameters, and intestinal morphology of broiler chickens

Itaconic acid (IA) is a biologically based unsaturated dicarboxylic acid secreted by mammalian cells. While IA has potential for use in multiple applications, information regarding the influence of IA on animal production remains scarce. This study investigated the effects of dietary IA supplementation on the growth performance, nutrient digestibility, slaughter variables, blood parameters, and intestinal morphology of broiler chickens. A total of 360 one-day-old Arbor Acre broiler chicks were allotted to 6 groups, with 10 chicks per cage and 6 replicates per group in a randomized complete block design. Broiler chicks were fed a basal diet with 0 (control), 0.2, 0.4, 0.6, 0.8, or 1.0% IA. The experimental period lasted from 1 to 42 d of age. Dietary IA supplementation did not affect average daily gain (ADG) and feed/gain ratio (F/G) but quadratically increased average daily feed intake (ADFI) and linearly increased crude protein (CP) digestibility during the grower period (d 22–42). A higher breast and thigh muscle yield and a lower abdominal fat yield were observed in a linear and quadratic manner with the IA supplementation. Adding IA to the diet had significant effects on superoxide dismutase (SOD), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and catalase (CAT) levels in serum at d 21 and on total antioxidation capacity (T-AOC) at d 42. There were linear and quadratic increases in villus height and the villus height/crypt depth ratio (V/C) of the duodenum and villus height of the jejunum with the supplementation of IA. Regression analyses for ADFI, dressed yield, breast and thigh muscle yield, abdominal fat yield, serum ALT, CAT, and SOD levels, villus length of the duodenum and jejunum, and V/C of the duodenum indicated that the optimal dietary IA supplementation would be from 0.4 to 0.7%. From an economic perspective, a level of 0.4% IA in the broiler diet is recommended for improving the nutrient digestibility, slaughter performance, antioxidant ability, and intestinal morphology of broiler chickens.

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.

Effects of Acute Diquat Poisoning on Liver Mitochondrial Apoptosis and Autophagy in Ducks

Diquat (DQ) is an effective herbicide and is widely used in agriculture. Due to persistent and frequent applications, it can enter into aquatic ecosystem and induce toxic effects to exposed aquatic animals. The residues of DQ via food chain accumulate in different tissues of exposed animals including humans and cause adverse toxic effects. Therefore, it is crucial and important to understand the mechanisms of toxic effects of DQ in exposed animals. We used ducks as test specimens to know the effects of acute DQ poisoning on mechanisms of apoptosis and autophagy in liver tissues. Results on comparison of various indexes of visceral organs including histopathological changes, apoptosis, autophagy-related genes, and protein expression indicated the adverse effects of DQ on the liver. The results of our experimental trial showed that DQ induces non-significant toxic effects on pro-apoptotic factors like BAX, BAK1, TNF-α, caspase series, and p53. The results revealed that anti-apoptotic gene Parkin was significantly upregulated, while an upward trend was also observed for Bcl2, suggesting that involvement of the anti-apoptotic factors in ducklings plays an important role in DQ poisoning. Results showed that DQ significantly increased the protein expression level of the autophagy factor Beclin 1 in the liver. Results on key autophagy factors like LC3A, LC3B, and p62 showed an upward trend at gene level, while the protein expression level of both LC3B and p62 reduced that might be associated with process of translation affected by the pro-apoptotic components such as apoptotic protease that inhibits the occurrence of autophagy while initiating cell apoptosis. The above results indicate that DQ can induce cell autophagy and apoptosis and the exposed organism may resist the toxic effects of DQ by increasing anti-apoptotic factors.