Search Results (101)

Background/Objectives: Rutin (RT), a promising bioflavonoid, faces clinical limitations due to its poor solubility and bioavailability. In this study, we formulated RT-loaded phytosome nanoparticles (RT-PNPs) via thin-layer hydration and characterized their morphology, size distribution, and zeta potential. Methods: We established a mouse model of Ehrlich ascites carcinoma (EAC), randomly allocating ninety female Swiss albino mice into six groups: untreated controls, RT-treated, RT-PNP-treated, EAC, EAC + RT, and EAC + RT-PNPs. Tumor induction and treatment protocols were controlled, with the oral administration of 25 mg/kg/day of RT or RT-PNPs for 20 days. We comprehensively assessed survival, body weight, ascitic fluid/tumor volume, and cell viability and performed detailed hematological, serum biochemical, and tumor marker analyses. Multiorgan (liver and kidney) function and redox homeostasis were evaluated through enzymatic assays for SOD, CAT, GSH-Px, and GSH, as well as lipid peroxidation assessment. Proinflammatory cytokines and tumor markers (AFP, CEA, CA19-9, CA125, and CA15-3) were quantified via ELISA. Results: Gene expression profiling (TP53, Bax, and Bcl-2) and flow cytometry (p53 and Ki-67) elucidated the modulation of apoptosis. Histopathological scoring documented organ protection, while advanced multivariate (heatmap and principal component) analyses revealed distinct treatment clusterings. The RT-PNPs demonstrated potent anti-tumor, antioxidant, anti-inflammatory, and apoptosis-inducing effects, outperforming free RT in restoring physiological markers and tissue integrity. Conclusions: The current results underscore the potential of RT-PNPs as a multifaceted therapeutic approach to EAC, leveraging nanoparticle technology to optimize efficacy and systemic protection. Full article

Purpose: We previously reported that the systemic administration of preprogrammed mouse hematopoietic bone marrow-derived progenitor cells (HSPCs) improved visual function and restored a functional retinal pigment epithelial (RPE) layer. Here, we investigated the potential impact of donor vs. host age on systemic cellular therapy in a murine model of retinal degeneration. Methods: HSPCs from young (8 weeks) and old (15 months) mice were programmed ex vivo with a lentiviral vector expressing the RPE65 gene (LV-RPE65) and systemically administering into young or old SOD2 KD mice. Visual loss and pathological changes were evaluated by electroretinogram (ERG), optical coherence tomography (OCT), histology, and immunohistochemistry. Results: Old donor HSPCs administered to old manganese superoxide dismutase (SOD2) knockdown (KD) recipient mice offered the least benefit. This was exemplified by the reduced recruitment and incorporation of LV-RPE65 HSPC into the RPE layer, as well as decreased improvement in visual function, retinal thinning, and limited reduction in oxidative damage and microglial activation. LV-RPE65 HSPC from young mice incorporated into the RPE layer of old SOD2 KD mice, though to a lesser extent than young cells administered to young hosts, offered some level of protection. By contrast, LV-RPE65 HSPCs from old mice, located to the subretinal space of young host mice, reduced visual loss, although some retinal pathology was observed. Conclusions: The administration of LV-RPE65 HSPC from old donors to old SOD2 KD mice offered the least improvement. Translational Relevance: Our findings highlight how both donor and recipient age impact the success of HSPC-based retinal therapy and using cells from aged donors for AMD treatment may have some limitations. Full article

The excessive emission of cadmium (Cd²⁺) poses a serious threat to the aquatic environment due to its high toxicity and bioaccumulation potential. This study constructed three types of vertical-subsurface-flow constructed wetlands configured with iron–carbon–zeolite composite substrates, including an iron–carbon–zeolite constructed wetland (TF-CW), a zeolite–iron–carbon constructed wetland (FT-CW), and an iron–carbon–zeolite mixed constructed wetland (H-CW), to investigate the purification performance and mechanisms of constructed wetlands for cadmium-containing wastewater (0~6 mg/L). The results demonstrated that iron–carbon–zeolite composite substrates significantly enhanced Cd²⁺ removal efficiency (>99%) through synergistic redox-adsorption mechanisms, where the iron–carbon substrate layer dominated Fe-Cd co-precipitation, while the zeolite layer achieved short-term cadmium retention through ion-exchange adsorption. FT-CW exhibited superior NH₄⁺-N removal efficiency (77.66%~92.23%) compared with TF-CW (71.45%~88.05%), while iron–carbon micro-electrolysis effectively inhibited NO₃⁻-N accumulation (<0.1 mg/L). Under cadmium stress, Typha primarily accumulated cadmium through its root systems (>85%) and alleviated oxidative damage by dynamically regulating antioxidative enzyme activity, with the superoxide dismutase (SOD) peak occurring at 3 mg/L Cd²⁺ treatment. Microbial community analysis revealed that iron–carbon substrates promoted the relative abundance of Bacteroidota and Patescibacteria as well as the enrichment of Saccharimonadales, Thauera, and Rhodocyclaceae (genera), enhancing system stability. This study confirms that iron–carbon–zeolite CWs provide an efficient and sustainable technological pathway for heavy metal-contaminated water remediation through multidimensional mechanisms of “chemical immobilization–plant enrichment–microbial metabolism”. Full article

Mesocotyl elongation is the key determinant of deep-sowing tolerance in maize. Sowing at an appropriate depth allows the seedling to exploit water and nutrients stored in deeper soil layers, thereby enhancing its ability to withstand drought and other abiotic stresses. Mesocotyl elongation is regulated by the phytohormones brassinosteroid (BR), auxin (IAA), gibberellin (GA), and reactive oxygen species (ROS). However, whether and how BR coordinates IAA, GA, and ROS to control mesocotyl elongation in maize remains unclear. Here, we demonstrated that BRs orchestrate ROS, IAA, and GA signaling to remodel cell-wall metabolism in mesocotyl cells, promote cell elongation, and, consequently, strengthen deep-sowing tolerance. BR promoted mesocotyl elongation through multiple routes: (1) decreasing the contents of cell-wall components (hemicellulose, cellulose, and pectin); (2) activating cell-wall-loosening enzymes (cellulase, pectinase, and acidic xylanase); and (3) disturbing ROS homeostasis by elevating superoxide dismutase (SOD) activity. Combined treatments of BR with either IAA or GA further enhanced mesocotyl elongation in a concentration-dependent manner. In deep-sowing trials (15 cm), application of BR alone or in combination with IAA or GA markedly increased mesocotyl length and emergence rate, thereby improving deep-sowing tolerance. Our work indicated that BR integrated ROS, IAA, and GA signals to restructure the cell wall and derived mesocotyl cell elongation, providing both theoretical insights and practical strategies for breeding maize varieties with enhanced deep-sowing tolerance. Full article

Aluminium (Al) is a widespread environmental contaminant known to induce oxidative stress and genotoxic effects in aquatic organisms. While its neurotoxic properties are well documented, the molecular impact of Al on the visual system remains poorly understood. In this study, adult zebrafish (Danio rerio) were exposed to 11 mg/L Al for 10, 15, and 20 days to investigate the oxidative and genotoxic responses in ocular tissue. Activities of antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) were measured in eye supernatants to detect oxidative stress. Additionally, the activities of poly (ADP-ribose) polymerase (PARP) and poly (ADP-ribose) glycohydrolase (PARG) were assessed in tissue homogenates to evaluate oxidative DNA damage and repair processes. The results indicate that these enzymes respond to counteract the increased reactive oxygen species (ROS) induced by aluminium exposure. However, their activity may not sufficiently reduce ROS levels to fully prevent oxidative DNA damage, as evidenced by a significant rise in PARP activity during short exposure times. Over longer exposures, PARP activity returned to baseline, suggesting ocular cells may adapt to aluminium toxicity. We propose that this reduction in PARP activity is a cellular survival mechanism, as sustained activation can deplete energy reserves and trigger cell death. Finally, thin-layer chromatography confirmed that PARG facilitates the breakdown of poly (ADP-ribose) (PAR) into ADP-ribose, demonstrating the dynamic regulation of the PAR cycle, which is crucial to preventing parthanatos. Full article

Orobanche cumana Wallr. is a root parasitic plant that causes considerable yield losses of up to 50% in sunflower Helianthus annuus plantations. The holoparasite fulfills its entire demand for water, minerals, and organic nutrients from the host’s vascular system. Agronomic practices alone are not effective in controlling this pest. This study investigated the mechanism of a verified plant growth-promoting strain, Streptomyces rochei D74, on the inhibition of the parasitism of O. cumana in a co-culture experiment. We conducted potted and sterile co-culture experiments using sunflower, O. cumana, and S. rochei D74. Our results suggest that the inoculated bacteria invoked the sunflower systemic resistance (SAR and ISR) by increasing the activity of resistance-related enzymes (SOD, POD, PPO, and PAL), the gene expression of systemic resistance marker genes (PR-1 and NPR1), ethylene synthesis genes (HACS. 1 and ACCO1), and JA synthesis genes (pin2 and lox). The expression levels of ISR marker genes (lox, HACS. 1, ACCO1, and pin2) increased by 1.66–7.91-fold in the seedling stage. Simultaneously, S. rochei D74 formed a protective layer on the sunflower root surface, preventing O. cumana from connecting to the vascular system of the sunflower roots. In addition, S. rochei D74 reduced 5DS synthesis of the strigol precursor substance, resulting in a reduction in O. cumana germination. These results demonstrated that the S. rochei D74 strain improved systemic resistance and decreased seed germination to prevent O. cumana parasitism. Full article

Modified biochar can effectively improve the quality and environment of coastal saline–alkali soil, but its effects on the growth and development of halophytes and its mechanism are still unclear. This study systematically evaluated the growth-promoting effects and preliminary mechanisms of H₃PO₄-modified biochar (HBC) and H₃PO₄–kaolinite–biochar composite (HBCK) on the economically important halophyte Kosteletzkya virginica. The results demonstrated that the application of HBC/HBCK significantly enhanced plant growth, resulting in increases of over 55% in plant height and greater than 100% in biomass relative to the control. Multidimensional mechanistic analysis revealed the following: (1) accumulation of nitrogen (N), phosphorus (P), and potassium (K) increased by at least 40%, significantly enhancing nutrient uptake; (2) increases in the activities of superoxide dismutase (SOD) and peroxidase (POD) by over 100% and 70%, respectively, markedly boosting antioxidant capacity and effectively alleviating oxidative stress; (3) molecular regulation via the activation of transcription factor networks (HSP, MYB, TCP, AP2/ERF, bZIP, and NLP) and modulation of key genes in ABA, BR, and JA signaling pathways (CYP707A, CYP90, and OPR2), establishing a multi-layered stress adaptation and growth promotion system. Beyond assessing the growth-promoting effects of modified biochars, this study provides novel insights into the regulatory transcription factor networks and phytohormone signaling pathways, offering theoretical foundations for the molecular design of biochars for saline–alkali soil remediation. Full article

The greater amberjack (Seriola dumerili), a key species in marine aquaculture, relies heavily on its intestine for nutrient absorption and immune function. However, the structural and functional specialization of its intestinal segments remains poorly understood. In this study, we divided the intestine of S. dumerili into foregut, midgut, and hindgut, and conducted a multi-omics analysis integrating histological staining (H&E/AB-PAS), digestive enzyme assays, transcriptome sequencing, and 16S rRNA microbiota profiling to characterize structural, functional, molecular, and microbial differences across intestinal segments. Histological examinations revealed that brush border microvillus length, muscle layer thickness, and folding height were significantly greater in the foregut and hindgut compared to the midgut, while mucus and goblet cell density was higher in the foregut and midgut. Digestive enzyme assays showed that lipase activity peaked in the foregut, α-amylase in the midgut, and protease in the midgut and hindgut. Alkaline phosphatase (AKP) and acid phosphatase (ACP) activities were highest in the foregut and midgut. Immune-related enzyme activities (SOD (Superoxide dismutase), GSH-Px (Glutathione peroxidase), T-AOC (Total Antioxidant Capacity)) were elevated and MDA levels were lower in the midgut, indicating its role as the primary immune site. Transcriptome analysis identified segment-specific expression of nutrient transporters, such as slc6a19b (hindgut, protein), apoa1b (foregut, lipid), and slc37a4 (midgut, carbohydrate). Microbiome analysis revealed Ruminococcus dominance in the foregut (lipid digestion) and Prevotella, Bifidobacterium, and Lactobacillus enrichment in the midgut (carbohydrate metabolism and immunity). These findings highlight functional zonation in S. dumerili: the foregut specializes in lipid digestion, the midgut in carbohydrate metabolism and immunity, and the hindgut in protein digestion. This study provides foundational insights for optimizing aquaculture practices and advancing research in nutrition, immunology, and disease modeling in S. dumerili. Full article

The hypoxic microenvironment is the main challenge for the repair of damaged tissue, and oxygen supply is an effective means of alleviating hypoxia. In this study, a series of core–shell-structured calcium peroxide/poly(ethylene glycol)@silica (CPO@SiO₂) nanoparticles are prepared to generate oxygen steadily. The size of the CPO@SiO₂ nanoparticles ranges from 205 to 302 nm, with a narrow polydispersity index (PDI). In this system, the nano CPO core acts as the oxygen source to improve hypoxia, while the SiO₂ shell layer serves as the physical barrier to control the oxygen-generating rate and improve biocompatibility. The results suggest that the thickness of the SiO₂ shell layer can be modulated by adjusting the amount of tetraethyl orthosilicate (TEOS). The prepared CPO@SiO₂ nanoparticles show a controlled oxygen-generating rate. Moreover, compared with CPO, the CPO@SiO₂ nanoparticles have good biocompatibility. To assess the modulating effects for the hypoxic microenvironment, L929 cells are co-cultured with CPO@ SiO₂ nanoparticles under hypoxia. The results suggest that the CPO@ SiO₂ nanoparticles can support the cell survival under hypoxia. Moreover, they can effectively decrease oxidative stress damage and reduce the levels of expression of hypoxia-induced superoxide dismutase (SOD) and malondialdehyde (MDA). Therefore, the prepared CPO@ SiO₂ nanoparticles with controlled oxygen-generating properties could be a promising candidate for repairing damaged tissue. Full article

The rapid advancement of deep learning has catalyzed progress in salient object detection (SOD), extending its impact to the domain of optical remote sensing images (ORSIs). Despite increasing attention, salient object detection for optical remote sensing images (ORSI-SOD) remains highly challenging due to the intrinsic complexities of remote sensing scenes. In particular, severe variations in object scale and quantity, cluttered backgrounds, and irregular object morphologies significantly hinder accurate target localization and boundary delineation. In response to these challenges, we introduce the Multi-scale Contextual Fusion Network (MCFNet) for ORSI-SOD. MCFNet incorporates a Semantic-Aware Attention Module (SAM), which provides explicit semantic guidance during feature extraction. By producing preliminary semantic masks, SAM enables the network to capture long-range contextual dependencies, thereby enhancing localization accuracy for salient objects exhibiting substantial scale variation and structural complexity. In addition, MCFNet integrates a Contextual Interconnection Module (CIM), which promotes effective fusion of local and global contextual features. By facilitating cross-layer interactions and adopting a multiscale refinement strategy, CIM enriches texture representations while suppressing background interference, leading to smoother object boundaries and more precise delineation of salient regions. Extensive evaluations conducted on three standard ORSI-SOD benchmark datasets demonstrate the superior performance of MCFNet compared to existing methods, highlighting its robustness and efficiency in handling challenging remote sensing scenarios. Full article

Alzheimer’s disease (AD) is characterized by oxidative stress, amyloid-beta (Aβ) deposition, and tau hyperphosphorylation. While polysaccharides have demonstrated anti-AD effects, the properties of Cremastra appendiculata polysaccharides (CAPs) remain underexplored. This study evaluates the physicochemical properties, antioxidant activity, anti-AD effects, and underlying mechanisms of CAP in vitro and in Caenorhabditis elegans (C. elegans) AD models. CAP, containing 22.37% uronic acid, is stable below 270 °C and adopts a triple helix structure. Scanning electron microscopy (SEM) reveals an irregular layered architecture. In vitro, CAP exhibits significant antioxidant activity, protecting PC12 cells from Aβ-induced cytotoxicity. In C. elegans, CAP extends the lifespan in a concentration-dependent manner without affecting growth, alleviating tau-induced locomotor defects, reducing Aβ-induced paralysis and serotonin hypersensitivity, and decreasing Aβ deposition by 79.96% at 2.0 mg/mL. CAP enhances antioxidant capacity and heat resistance by reducing reactive oxygen species (ROS) levels and increasing glutathione S-transferase 4 (GST-4) and glutathione peroxidase (GSH-Px) activities. Additionally, CAP upregulates key genes in the insulin/insulin-like growth factor signaling pathway, including daf-16 and skn-1, along with their downstream targets (sod-3, ctl-1, gst-4, hsp-70). These findings suggest that CAP has potent antioxidant and anti-AD effects, alleviating Aβ- and tau-induced toxicity, and may serve as a promising therapeutic agent for Alzheimer’s disease. Full article

This study aimed to investigate the effects of different supplemental amounts of dandelion flavonoid extracts (DFE) in diets on nutrients in chicken, slaughtering performance, blood biochemical indexes and antioxidant capacity of spent laying hens. A total of 180 560-day-old spent Hy-Line Brown laying hens were randomly divided into five groups. The control group was fed the basal diet, while the experimental groups were supplemented with DFE at levels of 1000, 2000, 4000, and 8000 mg/kg (as T1, T2, T3, and T4 group) in the basal diet, respectively. The variables measured included the content of dandelion flavonoids in layer hen thigh meat and breast meat, slaughter performance, blood biochemical indexes, and antioxidant capacity. Data were subjected to a one-way analysis of variance (one-way ANOVA) to assess the impact of DFE supplementation compared to the control group on study outcomes. The results showed that dietary supplementation with DFE can increase the content of dandelion flavonoids in layer hen meat. The contents of rutin in layer hen breast meat of groups T1, T2, T3, and T4 were 1.37, 4.41, 16.26, and 36.03 ng/g, respectively, and the contents of quercetin was 2.58, 1.36, 4.98, 12.48 ng/g. In layer hen thigh meat of groups T1, T2, T3, and T4, the contents of rutin were 11.48, 15.98, 44.43, 122.32 ng/g, and the contents of quercetin were 9.96, 13.14, 23.15, 38.09 ng/g, respectively. The addition of DFE increased the total phenol content of the feed and highly significantly elevated the total phenol content of layer hen meat (p < 0.01), and the total phenol content of chicken meat was strongly and positively correlated with the total phenol content of the feed. DFE supplementation significantly decreased abdominal fat percentage (p < 0.05) and increased crude fat content in chicken (p < 0.05). The addition of DFE reduced aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities (p < 0.05), decreased triglyceride (TG), total cholesterol (TC), low-density lipoprotein (LDL) cholesterol (LDL-C), glucose (GLU), and malondialdehyde (MDA) contents (p < 0.05), and increased the content of albumin (ALB), total antioxidant (T-AOC) capacity and total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px) activity (p < 0.05). Dietary supplementation of DFE at different concentrations could significantly increase the content of dandelion flavonoids in the muscle of spent laying hens, reduce the abdominal fat rate in hens, effectively reduce blood lipid levels, effectively increase crude fat content in thigh muscle, and enhance the body’s antioxidant capacity and liver function. Full article

In order to explore the effects of different irrigation methods on the physiological characteristics of mulch-free cotton in southern Xinjiang, the following experiments were carried out: (1) Different irrigation amount test: 300, 375, 450, 525, and 600 mm (represented by W1, W2, W3, W4, and W5) and a control (450 mm for film-covered cotton, represented by WCK) were set. (2) Drip irrigation frequency test: drip irrigation 12, 10, 8, and 6 times during the growth period (expressed by P12, P10, P8, and P6). Soil water dynamics, root distribution dynamics, chlorophyll fluorescence, leaf area index (LAI), SPAD (chlorophyll density), stress enzyme activities, and MDA (malondialdehyde) content were observed. The results showed that the average maximum change range of soil water content in the cotton field without film mulching was ±17.7%, which was 1.35 times higher than that in the cotton field with film mulching. Compared with cotton with film mulching, the root distribution characteristics of mulch-free cotton in the surface soil (0–20 cm) and the periphery (30 cm from the main root) decreased by 33.55–74.48% and 14.07–102.18%, respectively, while the root distribution characteristics in the deep layer (40–60 cm) increased by 49.62–242.67%, its average leaf green fluorescence parameters decreased by 9.03–50.44%, the activities of protective enzymes (SOD: superoxide dismutase, POD: peroxidase) decreased by 3.36–3.58%, the SPAD value decreased by 5.55%, and the MDA content increased by 3.17%, indicating that mulch-free cotton reduced the physiological function of cotton leaves, and the yield decreased by 42.07%. In the mulch-free treatments, the average root growth indexes were W2 > W3 > W4 > W5 > W1 and P12 > P10 > P8 > P6, and there was little difference between W2 and W3 and P12 and P10. With the increase in irrigation water and irrigation frequency, the initial fluorescence (F₀) of leaves in each period of mulch-free cotton showed a downward trend, and the maximum fluorescence (F_m), variable fluorescence (F_V), maximum photochemical efficiency (F_V/F_m), potential photochemical activity of PS II (F_V/F₀), electron transfer of PS II (F_m/F₀), and photosynthetic performance index (PIABS) showed an upward trend. In all water treatments, W3 and P12 had the highest SPAD value, protective enzyme activity, and the lowest MDA content, which was significantly different from other treatments except W4 and P10. The yield order of different treatments was W3 > W4 > W5 > W2 > W1, and the difference between W3 and W4 was not significant, but significant with W2 and W1. The irrigation frequency test was P12 > P10 > P8 > P6, and there was no significant difference between P12 and P10. We find that in the mulch-free treatment, all indicators of W3, W2, P12, and P10 were relatively high. It can be concluded that no mulching has a certain impact on cotton root distribution and leaf physiological function. When the irrigation amount is 450–525 mm and irrigation times is 10–12, it is beneficial for promoting root growth and plays a role in leaf physiological function, and the water use efficiency (WUE) is high, which can provide reference for the scientific water management of mulch-free cotton in production practice. Full article

In recent years, numerous advanced lightweight models have been proposed for salient object detection (SOD) in optical remote sensing images (ORSI). However, most methods still face challenges such as performance limitations and imbalances between accuracy and computational cost. To address these issues, we propose SggNet, a novel semantic- and graph-guided lightweight network for ORSI-SOD. The SggNet adopts a classical encoder-decoder structure with MobileNet-V2 as the backbone, ensuring optimal parameter utilization. Furthermore, we design an Efficient Global Perception Module (EGPM) to capture global feature relationships and semantic cues through limited computational costs, enhancing the model’s ability to perceive salient objects in complex scenarios, and a Semantic-Guided Edge Awareness Module (SEAM) that leverages the semantic consistency of deep features to suppress background noise in shallow features, accurately predict object boundaries, and preserve the detailed shapes of salient objects. To further efficiently aggregate multi-level features and preserve the integrity and complexity of overall object shape, we introduce a Graph-Based Region Awareness Module (GRAM). This module incorporates non-local operations under graph convolution domain to deeply explore high-order relationships between adjacent layers, while utilizing depth-wise separable convolution blocks to significantly reduce computational cost. Extensive quantitative and qualitative experiments demonstrate that the proposed model achieves excellent performance with only 2.70 M parameters and 1.38 G FLOPs, while delivering an impressive inference speed of 108 FPS, striking a balance between efficiency and accuracy to meet practical application needs. Full article

Essential oils serve as potential additives that can enhance immune respons and disease resistance and regulate the gut microbiota of fish. Here, this research aims to identify the impacts of eucalyptus essential oil (EEO) on growth, liver antioxidative and immune parameters, resistance to Streptococcus iniae, intestinal morphology and gut microbiota in Trachinotus ovatus. All fish (initial weight: 26.87 ± 0.30 g) were randomly allocated to 12 floating cages (2.0 × 2.0 × 2.0 m³) with each cage containing 100 fish and fed for 30 days. Four diets were manufactured with the supplementation of varying levels of EEO (control and 5.0, 10.0, and 15.0 mL/kg) and were named CG, EEO1, EEO2 and EEO3, respectively. The results showed that EEO1 and EEO2 diets significantly increased WGR, thickness of the intestinal muscle layer, and the ratio of villus height to crypt depth (V/C), while decreasing the intestinal crypt depth of T. ovatus (p < 0.05). Significantly increased activities of SOD and CAT and significantly reduced MDA levels were present in the EEO1 and/or EEO2 groups (p < 0.05). Moreover, the mRNA levels of nrf2, HO-1, GSH-Px, SOD, C4 and GR genes were significantly upregulated and the expression of keap1 and HSP70 genes were significantly downregulated within the EEO1 and EEO2 groups (p < 0.05). After challenge with S. iniae B240703 for 24 h, the bacterial load for five organs in the EEO2 group was less than that in the CG group (p < 0.05). In addition, the fish fed EEO1 and/or EEO2 diets had significantly lower abundances of pathogenic bacteria (Proteobacteria, Planctomycetota, Burkholderia-Caballeronia-Paraburkholderia, Pseudomonas and Blastopirellula) and a higher beneficial bacteria proportion (Firmicutes) than those fed the CG diets (p < 0.05). In conclusion, a moderate dietary m EO level (5.0~10.0 mL/kg) improved the growth and gut morphology, promoted liver immune response, enhanced resistance to S. iniae and modulated the gut microbiota of T. ovatus. Full article