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Article

Dietary Supplementation of Astragalus Polysaccharides Modulates Growth Physiology, Metabolic Homeostasis, and Innate Immune Responses in Rice Field Eels (Monopterus albus)

by
Chengcheng Wu
1,2,†,
Hang Yang
3,4,†,
Yutong Yang
1,2,
Quan Yuan
3,4,
Weiwei Lv
3,4,
Gelana Urgesa Ayana
1,2,
Mingyou Li
1,2,
Di Su
5,
Wenzong Zhou
3,4,* and
Qinghua Zhang
1,2,*
1
Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 201306, China
2
China National Pathogen Collection Center for Aquatic Animals, Shanghai Ocean University, Shanghai 201306, China
3
Eco-environmental Protection Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China
4
Key Laboratory of Integrated Rice-Fish Farming Ecosystem, Ministry of Agriculture and Rural Affairs, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China
5
Teaching Experimental Centre for Pharmacy, School of Pharmaceutical Sciences, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
*
Authors to whom correspondence should be addressed.
†
These authors contributed equally to this work.
Fishes 2025, 10(5), 213; https://doi.org/10.3390/fishes10050213
Submission received: 1 April 2025 / Revised: 28 April 2025 / Accepted: 30 April 2025 / Published: 6 May 2025
(This article belongs to the Special Issue Advances in Aquaculture Feed Additives)
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Abstract

To investigate the dietary effects of Astragalus polysaccharides (APSs) on the growth performance, lipid metabolism, antioxidant activity, and non-specific immunity of Asian swamp eel (Monopterus albus) during the domestication stage, fish were randomly allocated into quadruplicate groups receiving Tenebrio molitor-based diets supplemented with Astragalus polysaccharides (APSs) at graded concentrations of 0 (CON), 700 (APS1), 1400 (APS2), and 2100 (APS3) mg/kg body weight for 28 days. The results showed that dietary APSs at 700–1400 mg/kg·bw significantly enhanced the weight gain rate (WG) and decreased the feed conversion ratio (FCR) of M. albus (p < 0.05). Concurrently, hematological analysis revealed that hemoglobin levels increased by 19.9% and 23.0% in the 700 and 1400 mg/kg APS groups, respectively (p < 0.05). In terms of lipid metabolism, supplementation with APSs significantly increased the serum high-density lipoprotein (HDL) content in all treatment groups (p < 0.05). Lower serum triglyceride (TG) levels were found in the APS2 group (p < 0.05), and decreased triglyceride (TG), cholesterol (CHO), and low-density lipoprotein (LDL) levels were displayed in the APS3 group (p < 0.05). Among the antioxidant parameters, the supplementation with 700 mg/kg·bw APSs significantly increased the glutathione peroxidase (GSH-Px) and catalase (CAT) activity levels of M. albus (p < 0.05). The APS2 group had a significantly increased total antioxidant capacity (T-AOC) and CAT activity levels (p < 0.05), and the APS3 group had significantly increased CAT activity levels (p < 0.05). In addition, the APS1 and APS3 groups had significantly reduced malondialdehyde (MDA) levels (p < 0.05). In terms of non-specific immunity, the APS1 and APS2 groups showed significantly increased superoxide dismutase (SOD) and lysozyme (LZM) activity levels of M. albus (p < 0.05), and the addition of 700 mg/kg·bw APSs significantly increased the levels of alkaline phosphatase (AKP) activity (p < 0.05). Furthermore, the levels of acid phosphatase (ACP) activity were significantly increased in all experimental groups (p < 0.05). In conclusion, the optimal APS addition for T. molitor as biocarrier bait is 700 mg/kg, corresponding to 352 mg/kg, which elicits improvements in the growth parameters, lipid homeostasis regulation, oxidative stress mitigation, and innate immune potentiation of M. albus during the domestication stage.
Keywords:
Monopterus albus; Astragalus polysaccharides; growth; lipid metabolism; antioxidant capacity; innate immunity
Key Contribution: Dietary addition supplementation with Astragalus polysaccharides elicited improvements in the growth parameters, lipid homeostasis regulation, oxidative stress mitigation, and innate immune potentiation of M. albus during the domestication stage.

1. Introduction

The rice field eel (Monopterus albus), a protogynous hermaphroditic teleost species within the order Synbranchiformes, has emerged as a pivotal species in China’s aquaculture industry owing to its substantial nutritional profile and pharmacological properties. As documented in the China Fishery Statistical Yearbook (2024), the national production of M. albus achieved a record yield exceeding 330,000 tons in 2024 [1]. However, the intensification of farming systems has precipitated physiological stress responses in this species, manifested through immunosuppression and increased disease susceptibility. Current prophylactic measures predominantly employ broad-spectrum antimicrobial agents, a practice that has engendered multidrug-resistant bacterial strains while exacerbating environmental contamination and residual toxicity in aquatic products. This paradigm underscores the urgent need to develop natural immunostimulants as sustainable alternatives within precision aquaculture frameworks. Phytogenic feed additives, particularly those derived from traditional Chinese medicine, have gained prominence due to their pleiotropic bioactivities, environmental compatibility, and absence of drug residues, positioning them as viable candidates for immunonutrition strategies in aquatic species [2].
Astragalus membranaceus, a leguminous plant with a 2000-year history in Chinese pharmacopeia, synthesizes Astragalus polysaccharides (APSs) as its principal bioactive constituents, comprising heteropolysaccharides with α-(1→4)-glucan backbones and arabinogalactan side chains [3]. Studies have demonstrated that APSs exhibit diverse biological functions, including lipid regulation, growth promotion, antioxidant activity, anti-inflammatory effects, and immunomodulation [4]. In recent years, dietary supplementation with APSs in livestock and poultry has been extensively documented for improving nutritional status and physiological conditions [5,6]. Beyond terrestrial applications, Astragalus polysaccharides exhibit cross-species applicability in aquaculture systems. Studies have reported that the addition of APSs significantly enhanced the growth potentiation of bluegill sunfish Lepomis macrochirus [7], koi Cyprinus carpio [8], and Nile tilapia Oreochromis niloticus [9]; improved the antioxidant capacity of largemouth bass Micropterus salmoides [10], large yellow croaker Larimichthys crocea [11], and turbot Scophthalmus maximus [12]; and enhanced the immunity of Nile tilapia [9], crucian carp Carassius auratus [8], and Amur catfish Silurus asotus [13]. Also, dietary APSs improved growth, immunity, and disease resistance in crustaceans, as well as enhancing growth performance and immune parameters in red swamp crayfish Procambarus clarkii [14] and upregulating immune-related gene expression in Chinese mitten crab Eriocheir sinensis [15]. A prior study evaluated the effects of a compound herbal formula (containing 0.05% andrographolide, 0.05% tributyrin, 0.02% taurine, and 0.05% APSs) on M. albus growth and physiology [16]. However, no research has yet investigated the isolated impact of APSs on the growth performance and immune function of M. albus during the domestication stage.
At present, most farmed M. albus originate from wild-caught juveniles, and they need to be domesticated during the feeding process, wherein T. molitor emerges as a superior functional carrier matrix for bioactive compound delivery during transitional husbandry protocols. Artificial cultivation requires a 28-day initial feeding acclimation period, during which mortality rates reach 40–80%. Therefore, this study evaluated the effects of APSs on growth, lipid metabolism, antioxidant capacity, and non-specific immunity in M. albus during the domestication stage, aiming to identify effective additives for specialized feeds.

2. Materials and Methods

2.1. Experimental Materials

Experimental specimens of M. albus (25.26 ± 0.16 g) and colony-reared T. molitor larvae were sourced from the Zhuanghang Comprehensive Experiment Station (Shanghai Academy of Agricultural Sciences, Shanghai, China). Astragalus polysaccharides (APSs > 70% purity, Xi’an Ruibo BioTech, Xi’an, China) were integrated into T. molitor biocarriers, whose nutritional profile comprised 52.0% crude protein, 32.0% lipids, 5.5% fiber, and 5.0% ash on a dry weight basis.

2.2. Experimental Design and Feeding Management

A total of 720 M. albus were stratified into four experimental groups (n = 3 replicates) receiving APS-fortified T. molitor formulations at incremental doses of 0 (CON), 700 (APS1), 1400 (APS2), and 2100 (APS3) mg/kg·bw. The method of addition involved evenly sprinkling CGA on hungry T. molitor, which were fed to the fish within 30 min after eating. HPLC quantification revealed actual APS retention levels of 0.5, 352, 781, and 1120 mg/kg in the respective biocarriers. The 28-day trial was conducted in recirculating aquaculture systems (RASs) equipped with concrete tanks (1.2 × 1.5 × 0.8 m) with continuous water treatment protocols. Water parameters included dissolved oxygen (6.0–7.5 mg/L), temperature (22–28 °C), and a natural photoperiod. M. albus were fed once daily at 16:00 h, with a daily feeding rate of 2–3% body weight. Residual feed was removed 20 min post-feeding, and feed intake was recorded. Mortalities were counted, and M. albus were weighed daily. Final body weights were measured for each group at trial termination.

2.3. Sample Collection and Analysis

At the end of the feeding experiment, the M. albus were fasted for 24 h. Three individuals per group were anesthetized with MS-222 (100 mg/L) for blood collection via decapitation. Whole blood was incubated at 4 °C overnight, followed by centrifugation at 3000 rpm for 10 min to isolate serum. Livers were excised immediately on ice, rinsed with 0.9% saline to remove surface blood, blotted with filter paper, weighed, and then stored for antioxidant enzyme activity and non-specific immune enzyme activity analyses.

2.3.1. Growth Indicators

Post-trial biometric analysis employed standardized aquacultural metrics for physiological evaluation. Vitality metrics were quantified as follows: Survival Rate (%) = (N_final/N_initial) × 100. Growth dynamics were assessed through the Weight Gain Ratio (%) = [(Wt − W0)/W0] × 100, where W0 and Wt represent the initial/final mean body mass (g). Nutritional efficiency was determined by the formula Feed Conversion Ratio = ΣFeed intake (g)/ΔBiomass (g).

2.3.2. Hematological Analysis

Whole blood parameters were quantified using a Mindray BC-2800vet veterinary hematology analyzer (Shenzhen, China), including white blood cell (WBC) count, red blood cell (RBC) count, hemoglobin (HGB) concentration, hematocrit (HCT), platelet count (PLT), mean platelet volume (MPV), and platelet distribution width (PDW).

2.3.3. Lipid Metabolism Analysis

Serum lipid profiling was conducted using commercial assay kits (Nanjing Jiancheng Institute of Biotechnology, Nanjing, China) through spectrophotometric quantification. Analytical parameters included the following: (1) triglyceride (TG) concentration and (2) cholesterol homeostasis markers comprising total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) subfractions. All biochemical analyses strictly adhered to manufacturer-certified protocols.

2.3.4. Antioxidant Capacity Assessment and Non-Specific Immunity Evaluation

Liver tissues were homogenized (1:9 w/v) in ice-cold 0.9% saline and centrifuged at 2500 rpm for 10 min, and the supernatant was collected for determination. The activity of total antioxidant capacity (T-AOC), catalase (CAT), malondialdehyde (MDA), glutathione peroxidase (GSH-PX), lysozyme (LZM), superoxide dismutase (SOD), alkaline phosphatase (AKP), and acid phosphatase (ACP) in the liver was determined using reagent kits (Jiancheng, Nanjing, China), and an assay was performed by referring to the kit’s instructions. Simply, the liver was homogenized to obtain the supernatant, and the total protein (TP) content was measured for error calibration. Lastly, the supernatant and reagents were combined and used for measuring the abovementioned parameters using a microplate reader or colorimetry methods.

2.4. Statistical Analysis

All experimental data were recorded in Excel, with results expressed as mean ± standard deviation (SD). Statistical analyses were performed using SPSS 22.0. One-way analysis of variance (ANOVA) followed by Duncan’s multiple range test was applied for multiple comparisons. Differences were considered statistically significant at p < 0.05.

3. Results

3.1. Growth Performance

Compared to the control group, the final weight and WG were significantly increased in the APS1 and APS2 groups (p < 0.05), while the FCR of the APS1 and APS2 groups was significantly lower than that of the control group (p < 0.05). Moreover, no significant differences (p > 0.05) in the SR were observed among all groups (Table 1).

3.2. Hematological Parameters

AS shown in Table 2, no significant differences (p > 0.05) were observed in hematological parameters, including WBC, RBC, HCT, PLT, MPV, and PDW, among all experimental groups. However, HGB exhibited a dose-dependent trend, increasing initially and then decreasing with rising APS supplementation. Specifically, HGB concentrations significantly increased in the APS1 and APS2 groups (p < 0.05), while the APS3 group showed no significant change compared to the control.

3.3. Lipid Metabolism Parameters

In Table 3, the HDL content in all APS groups was significantly higher (p < 0.05), and the TG levels in APS2 and APS3 were lower than those of the control group (p < 0.05). In addition, APS supplementation with 2100 mg/kg resulted in significantly decreased CHO and LOD levels (p < 0.05).

3.4. Antioxidant Capacity Parameters

In Figure 1, the antioxidant capacity parameters were influenced by the supplementation of APSs. T-AOC exhibited a quadratic response to increasing APS doses, peaking in the APS2 group with significantly higher activity levels compared to the control (p < 0.05). Similarly, GSH-Px activity followed a dose-dependent pattern, reaching the maximum levels in the APS1 group (p < 0.05). All experimental groups showed significantly higher CAT activity levels than the control group (p < 0.05). Furthermore, MDA content was significantly reduced in the APS1 and APS3 groups (p < 0.05).

3.5. Non-Specific Immunity Parameters

In Figure 2, all experimental groups exhibited elevated hepatic non-specific immune enzyme activities when compared to the control group. The activities of SOD, LZM, and AKP displayed a quadratic dose–response pattern, peaking in the APS1 group (SOD and AKP, p < 0.05) and APS2 group (LZM, p < 0.05). In contrast, ACP activity showed a linear increase, with all APS-treated groups demonstrating significantly higher activity levels than the control (p < 0.05).

4. Discussion

As the primary bioactive component of Astragalus membranaceus, APSs have been reported to enhance growth performance in various farmed fish species [17]. In this study, APS supplementation with 700 mg/kg and 1400 mg/kg in biocarrier bait significantly increased the WG and reduced the FCR in M. albus during the domestication stage. Similar findings were observed in large yellow croaker larvae, where dietary APSs with 500–1000 mg/kg improved growth performance [18], and a largemouth bass diet supplemented with 2000 mg/kg APS enhanced growth and feed utilization [10]. Comparable growth-promoting effects of APSs have also been documented in Nile tilapia [9] and bluegill sunfish [7]. Notably, however, the highest APS level (2100 mg/kg·bw) in this study resulted in no significant improvement in the FCR. This aligns with observations in crucian carp, where excessive APS supplementation failed to positively influence feed efficiency [19]. These discrepancies may arise from inter-specific variations, developmental stages, feeding methods, experimental designs, or trial durations. The present study employed a bioencapsulation strategy using T. molitor as carriers. Current farming practices rely heavily on wild-caught juveniles that resist formulated feeds during early acclimation. Live feeds, such as T. molitor, Hermetia illucens, and Musca demestica, are thus critical for transitional training. Moreover, live feeds provide comprehensive nutrition, particularly advantageous for juvenile and broodstock stages due to their high protein content and palatability. Additionally, the bioactive compounds encapsulated in live carriers remain structurally intact, avoiding the thermal denaturation and functional deactivation that often occur during the high-temperature processing of pelleted feeds. This method also minimizes nutrient leaching into water, which is a critical limitation of conventional feed delivery systems. By replicating the natural feeding ecology of M. albus during the initial acclimation phase, our experimental design provides actionable insights for commercial farming practices. These findings collectively suggested that moderate APS supplementation enhances growth performance, likely through the upregulation of digestive enzyme activities and the stimulation of nutrient absorption pathways [18].
Blood composition in fish is influenced by metabolism, nutritional status, and immune responses. As the primary bioactive component of Astragalus membranaceus, APSs exhibit potent hematopoietic activity by stimulating colony-forming unit-erythrocyte (CFU-E) and burst-forming unit-erythrocyte (BFU-E), thereby enhancing hemoglobin synthesis [20]. Our results demonstrated that dietary supplementation with 700 mg/kg and 1400 mg/kg APSs significantly elevated HGB levels in M. albus compared to the control group. Hemoglobin, primarily responsible for oxygen transport and storage, also regulates pH homeostasis, modulates carbon monoxide levels, and participates in immune responses [21]. Similar findings were reported in Catla catla, where HGB levels increased following APS supplementation at 200–300 mg/kg [22]. These results suggest that APSs may improve oxygen acquisition in M. albus, enhancing survival under hypoxic conditions (e.g., high-density farming or transportation stress) while simultaneously meeting the elevated oxygen demands of physiological metabolic processes.
As a critical metabolic transport system, blood regulates lipid metabolism in fish, with serum TG and total CHO levels serving as key indicators [23]. Our results revealed a dose-dependent reduction in serum TG and CHO levels in M. albus supplemented with APSs. Specifically, higher APS supplementation resulted in significant decreases (p < 0.05) in these parameters. This aligns with findings in Nile tilapia, where 0.1% Astragalus extract supplementation for 40 days significantly reduced serum TG and CHO [24], and mice (Mus musculus) demonstrated improved lipid metabolism following APS administration [25]. Notably, APS supplementation induced a quadratic response in serum HDL levels, peaking at intermediate doses while remaining significantly elevated compared to the control across all treatment groups. Conversely, LDL levels exhibited a gradual decline, with a significant reduction observed only at the highest APS dose (2100 mg/kg) (p < 0.05). These findings correlate with prior reports that APSs modulate lipid profiles in Nile tilapia exposed to heavy metal thallium [26]. Mechanistically, HDL facilitates reverse cholesterol transport from peripheral tissues to the liver for catabolism, whereas excessive LDL promotes arterial lipid deposition, increasing the risks of atherosclerosis and vascular injury [27]. We hypothesize that APSs delivered via mealworm carriers (1400–2100 mg/kg bw) regulate lipid metabolism in M. albus by modulating lipoprotein concentrations, thereby enhancing lipid transport efficiency. However, the precise molecular mechanisms underlying this require further investigation.
SOD, LZM, AKP, and ACP are key non-specific humoral immune factors in fish, playing critical roles in immunological responses [28]. SOD activity is closely associated with immune function, while LZM serves as a sensitive biomarker for detecting foreign invasions. Additionally, ACP and AKP hydrolyze phosphate groups and are recognized as vital indicators for evaluating the immune status of aquatic animals [29]. Extensive studies have demonstrated the broad application of APSs as immunostimulants in aquaculture. In this study, the activities of SOD, LZM, AKP, and ACP in M. albus were significantly elevated following dietary APS supplementation. Specifically, the addition of 700 mg/kg and 1400 mg/kg APSs markedly enhanced SOD, LZM, and ACP activities. Similar findings have been reported in large yellow croaker, in which 1000 mg/kg APSs significantly increased SOD, LZM, AKP, and ACP activities [30]. APS supplementation at 1200 mg/kg also improved SOD, LZM, AKP, and ACP activities in red swamp crayfish [14] and Chinese mitten crab [15], reducing disease susceptibility. Furthermore, the dietary inclusion of 0.15% and 0.30% APSs has been shown to enhance immunity and significantly elevate LZM activity in Nile tilapia [31]. Mechanistically, APSs may regulate host immunity by activating the TLR4-mediated MyD88-dependent signaling pathway [32]. Collectively, this study demonstrates that APS supplementation enhances the immunity of M. albus by upregulating SOD, AKP, LZM, and ACP activities.

5. Conclusions

In summary, dietary supplementation with APSs elicited improvements in the growth parameters, lipid homeostasis regulation, oxidative stress mitigation, and innate immune potentiation of M. albus during the domestication stage. Based on the findings of this study, an optimal APS dosage of 700 mg/kg, corresponding to 352 mg/kg, is recommended when administered via T. molitor as a biocarrier bait.

Author Contributions

Conceptualization, Q.Y.; methodology, W.L.; software, G.U.A.; validation, W.L.; formal analysis, H.Y. and W.L.; investigation, H.Y.; resources, M.L.; data curation, D.S.; writing—original draft, C.W. and Y.Y.; writing—review and editing, H.Y.; visualization, G.U.A. and M.L.; supervision, W.Z. and Q.Z.; project administration, W.Z. and Q.Z.; funding acquisition, H.Y. All authors have read and agreed to the published version of the manuscript.

Funding

This work was supported by the National Key Research and Development Program of China (2024YFD2401505); China Agriculture Research System of MOF and MARA (CARS-46); the Science and Technology Innovation Action Plan project of the Shanghai Municipal Commission of Science and Technology (No. 22YF1416600); and the Science and Technology Commission of Shanghai Municipality (22DZ2291200).

Institutional Review Board Statement

The ethical approval research scheme was approved by the Animal Care and Use Committee of Shanghai Ocean University (SHOU-DW-2023-006).

Informed Consent Statement

Written informed consent has been obtained from the patient(s) to publish this paper.

Data Availability Statement

The datasets generated for this study are available on request to the corresponding author.

Conflicts of Interest

The authors declare no conflicts of interest.

References

  1. Ministry of Agriculture and Rural Affairs. China Fishery Statistical Yearbook; China Agriculture Press: Beijing, China, 2024; p. 25.
  2. Abdel-Latif, H.M.; Abdel-Daim, M.M.; Shukry, M.; Nowosad, J.; Kucharczyk, D. Benefits and applications of Moringa oleifera as a plant protein source in aquafeed: A review. Aquaculture 2022, 547, 737369. [Google Scholar] [CrossRef]
  3. Shao, B.M.; Xu, W.; Dai, H.; Tu, P.; Li, Z.; Gao, X.M. A study on the immune receptors for polysaccharides from the roots of Astragalus membranaceus, a Chinese medicinal herb. Biochem. Biophys. Res. Commun. 2004, 320, 1103–1111. [Google Scholar] [CrossRef] [PubMed]
  4. Zhang, W.; Ma, W.; Zhang, J.; Song, X.; Sun, W.; Fan, Y. The immunoregulatory activities of astragalus polysaccharide liposome on macrophages and dendritic cells. Int. J. Biol. Macromol. 2017, 105, 852–861. [Google Scholar] [CrossRef] [PubMed]
  5. Wang, H.F.; Yang, W.R.; Yang, H.W.; Wang, Y.; Yang, Z.B.; Jiang, S.Z.; Zhang, G.G. Effects of Astragalus membranaceus on growth performance, carcass characteristics, and antioxidant status of broiler chickens. Acta Agric. Scand. Sect. A 2010, 60, 151–158. [Google Scholar]
  6. Gu, C.; Zeng, Y.; Tang, Z.; Wang, C.; He, Y.; Feng, X.; Zhou, L. Astragalus polysaccharides affect insulin resistance by regulating the hepatic SIRT1-PGC-1α/PPARα-FGF21 signaling pathway in male Sprague Dawley rats undergoing catch-up growth. Mol. Med. Rep. 2015, 12, 6451–6460. [Google Scholar] [CrossRef]
  7. Elabd, H.; Wang, H.P.; Shaheen, A.; Yao, H.; Abbass, A. Astragalus membranaceus (AM) enhances growth performance and antioxidant stress profiles in bluegill sunfish (Lepomis macrochirus). Fish Physiol. Biochem. 2016, 42, 955–966. [Google Scholar] [CrossRef]
  8. Wu, S. Dietary Astragalus membranaceus polysaccharide ameliorates the growth performance and innate immunity of juvenile crucian carp (Carassius auratus). Int. J. Biol. Macromol. 2020, 149, 877–881. [Google Scholar] [CrossRef]
  9. Zahran, E.; Risha, E.; AbdelHamid, F.; Mahgoub, H.A.; Ibrahim, T. Effects of dietary Astragalus polysaccharides (APS) on growth performance, immunological parameters, digestive enzymes, and intestinal morphology of Nile tilapia (Oreochromis niloticus). Fish Shellfish Immun. 2014, 38, 149–157. [Google Scholar] [CrossRef]
  10. Lin, S.M.; Jiang, Y.; Chen, Y.J.; Luo, L.; Doolgindachbaporn, S.; Yuangsoi, B. Effects of Astragalus polysaccharides (APS) and chitooligosaccharides (COS) on growth, immune response and disease resistance of juvenile largemouth bass, Micropterus salmoides. Fish Shellfish Immun. 2017, 70, 40–47. [Google Scholar] [CrossRef]
  11. Liu, Y.; Miao, Y.; Xu, N.; Ding, T.; Cui, K.; Chen, Q.; Zhang, J.; Fang, W.; Mai, K.; Ai, Q. Effects of dietary Astragalus polysaccharides (APS) on survival, growth performance, activities of digestive enzyme, antioxidant responses and intestinal development of large yellow croaker (Larimichthys crocea) larvae. Aquaculture 2020, 517, 734752. [Google Scholar] [CrossRef]
  12. Sun, Y.; Wang, X.; Zhou, H.; Mai, K.; He, G. Dietary Astragalus polysaccharides ameliorates the growth performance, antioxidant capacity and immune responses in turbot (Scophthalmus maximus L.). Fish Shellfish Immun. 2020, 99, 603–608. [Google Scholar] [CrossRef] [PubMed]
  13. Abdel-Latif, H.M.; Ahmed, H.A.; Shukry, M.; Chaklader, M.R.; Saleh, R.M.; Khallaf, M.A. Astragalus membranaceus extract (AME) enhances growth, digestive enzymes, antioxidant capacity, and immunity of Pangasianodon hypophthalmus juveniles. Fishes 2022, 7, 319. [Google Scholar] [CrossRef]
  14. Chang, Z.Q.; Ge, Q.Q.; Sun, M.; Wang, Q.; Lv, H.Y.; Li, J. Immune responses by dietary supplement with Astragalus polysaccharides in the Pacific white shrimp, Litopenaeus vannamei. Aquacult. Nutr. 2018, 24, 702–711. [Google Scholar] [CrossRef]
  15. Fu, L.; Zhou, G.; Pan, J.; Li, Y.; Lu, Q.; Zhou, J.; Li, X. Effects of Astragalus polysaccharides on antioxidant abilities and non-specific immune responses of Chinese mitten crab, Eriocheir sinensis. Aquacult. Int. 2017, 25, 1333–1343. [Google Scholar] [CrossRef]
  16. Che, C.B.; Shi, Y.; Hu, Y. Effects of two kinds of composite immunopotentiators on growth, immunity and physiological and biochemical indexes of rice field eel (Monopterus albus). Feed Ind. 2020, 41, 43–48. [Google Scholar]
  17. Jin, M.; Zhao, K.; Huang, Q.; Shang, P. Structural features and biological activities of the polysaccharides from Astragalus membranaceus. Int. J. Biol. Macromol. 2014, 64, 257–266. [Google Scholar] [CrossRef]
  18. Liu, H.; Liu, K.; Fu, H.; Ji, R.; Qu, X. Sunlight mediated cadmium release from colored microplastics containing cadmium pigment in aqueous phase. Environ. Pollut. 2020, 263, 114484. [Google Scholar] [CrossRef]
  19. Liu, J.; Zhang, P.; Wang, B.; Lu, Y.; Li, L.; Li, Y.; Liu, S. Evaluation of the effects of Astragalus polysaccharides as immunostimulants on the immune response of crucian carp and against SVCV in vitro and in vivo. Comp. Biochem. Phys. C 2022, 253, 109249. [Google Scholar] [CrossRef]
  20. Ren, F.; Qian, X.H.; Qian, X.L. Astragalus polysaccharide upregulates hepcidin and reduces iron overload in mice via activation of p38 mitogen-activated protein kinase. Biophys. Res. Commun. 2016, 472, 163–168. [Google Scholar] [CrossRef]
  21. Giardina, B. Hemoglobin: Multiple molecular interactions and multiple functions. An example of energy optimization and global molecular organization. Mol. Asp. Med. 2022, 84, 101040. [Google Scholar] [CrossRef]
  22. Harikrishnan, R.; Devi, G.; Van Doan, H.; Tapingkae, W.; Balasundaram, C.; Arockiaraj, J.; Ringø, E. Changes in immune genes expression, immune response, digestive enzymes-antioxidant status, and growth of catla (Catla catla) fed with Astragalus polysaccharides against edwardsiellosis disease. Fish Shellfish Immun. 2022, 121, 418–436. [Google Scholar] [CrossRef] [PubMed]
  23. Qiang, J.; Tao, Y.F.; Bao, J.W.; Chen, D.J.; Li, H.X.; He, J.; Xu, P. High fat diet-induced miR-122 regulates lipid metabolism and fat deposition in genetically improved farmed tilapia (GIFT, Oreochromis niloticus) liver. Front. Physiol. 2018, 9, 1422. [Google Scholar] [CrossRef] [PubMed]
  24. Wu, F.; Yang, C.; Wen, H.; Zhang, C.; Jiang, M.; Liu, W.; Tian, J.; Yu, L.; Lu, X. Improving low-temperature stress tolerance of tilapia, Oreochromis niloticus: A functional analysis of Astragalus membranaceus. J. World Aquacult. Soc. 2019, 50, 749–762. [Google Scholar] [CrossRef]
  25. Li, B.; Hong, Y.; Gu, Y.; Ye, S.; Hu, K.; Yao, J.; Ding, K.; Zhao, A.; Jia, W.; Li, H. Functional metabolomics reveals that Astragalus polysaccharides improve lipids metabolism through microbial metabolite 2-hydroxybutyric acid in obese mice. Engineering 2022, 9, 111–122. [Google Scholar] [CrossRef]
  26. Farag, M.R.; Alagawany, M.; Khalil, S.R.; Moustafa, A.A.; Mahmoud, H.K.; Abdel-Latif, H.M. Astragalus membranaceus polysaccharides modulate growth, hemato-biochemical indices, hepatic antioxidants, and expression of HSP70 and apoptosis-related genes in Oreochromis niloticus exposed to sub-lethal thallium toxicity. Fish Shellfish Immun. 2021, 118, 251–260. [Google Scholar] [CrossRef]
  27. Li, M.; Qiang, J.; Zhu, X.; Bao, J.; Tao, Y.; Zhu, H. Effect of Siberian ginseng water extract as a dietary additive on growth performance, blood biochemical indexes, lipid metabolism, and expression of PPARs pathway-related genes in genetically improved farmed tilapia (Oreochromis niloticus). Fishes 2022, 7, 149. [Google Scholar] [CrossRef]
  28. Xu, D.; Han, P.; Xia, L.; Gan, J.; Xu, Q. A comparative transcriptome analysis focusing on immune responses of Asian swamp eel following infection with Aeromonas hydrophila. Aquaculture 2021, 539, 736655. [Google Scholar] [CrossRef]
  29. Hu, X.; Yang, H.L.; Yan, Y.Y.; Zhang, C.X.; Ye, J.D.; Lu, K.L.; Hu, L.H.; Zhang, J.J.; Ruan, L.; Sun, Y.Z. Effects of fructooligosaccharide on growth, immunity and intestinal microbiota of shrimp (Litopenaeus vannamei) fed diets with fish meal partially replaced by soybean meal. Aquacult. Nutr. 2019, 25, 194–204. [Google Scholar] [CrossRef]
  30. Zhang, W.; Zhang, M.; Cheng, A.; Hao, E.; Huang, X.; Chen, X. Immunomodulatory and antioxidant effects of Astragalus polysaccharide liposome in large yellow croaker (Larimichthys crocea). Fish Shellfish Immun. 2020, 100, 126–136. [Google Scholar] [CrossRef]
  31. Farag, M.R.; Alagawany, M.; Khalil, S.R.; El-Hady, E.W.; Elhady, W.M.; Ismail, T.A.; Marini, C.; Cerbo, A.; Abdel-Latif, H.M. Immunosuppressive effects of thallium toxicity in Nile Tilapia fingerlings: Elucidating the rescue role of Astragalus membranaceus polysaccharides. Front. Vet. Sci. 2022, 9, 843031. [Google Scholar] [CrossRef]
  32. Zhou, L.; Liu, Z.; Wang, Z.; Yu, S.; Long, T.; Zhou, X.; Bao, Y. Astragalus polysaccharides exerts immunomodulatory effects via TLR4-mediated MyD88-dependent signaling pathway in vitro and in vivo. Sci. Rep. 2017, 7, 44822. [Google Scholar]
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Figure 1. Antioxidant enzyme activities of M. albus livers in different experimental groups. Different letters indicate statistical significance (p < 0.05) between dietary regimens. (A): total antioxidant capacity (T-AOC), (B): malondialdehyde (MDA), (C): glutathione peroxidase (GSH-PX), (D): catalase (CAT). CON, 0 mg/kg·bw; APS1, 700 mg/kg·bw; APS2, 1400 mg/kg·bw; APS3, 2100 mg/kg·bw.
Figure 1. Antioxidant enzyme activities of M. albus livers in different experimental groups. Different letters indicate statistical significance (p < 0.05) between dietary regimens. (A): total antioxidant capacity (T-AOC), (B): malondialdehyde (MDA), (C): glutathione peroxidase (GSH-PX), (D): catalase (CAT). CON, 0 mg/kg·bw; APS1, 700 mg/kg·bw; APS2, 1400 mg/kg·bw; APS3, 2100 mg/kg·bw.
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Figure 2. Non-specific immune enzyme activities of M. albus livers in different experimental groups. Different letters represent significant differences at p < 0.05; same or no letter represents no significant difference (p > 0.05). (A): superoxide dismutase (SOD), (B): lysozyme (LZM), (C): alkaline phosphatase (AKP), (D): acid phosphatase (ACP). CON, 0 mg/kg·bw; APS1, 700 mg/kg·bw; APS2, 1400 mg/kg·bw; APS3, 2100 mg/kg·bw.
Figure 2. Non-specific immune enzyme activities of M. albus livers in different experimental groups. Different letters represent significant differences at p < 0.05; same or no letter represents no significant difference (p > 0.05). (A): superoxide dismutase (SOD), (B): lysozyme (LZM), (C): alkaline phosphatase (AKP), (D): acid phosphatase (ACP). CON, 0 mg/kg·bw; APS1, 700 mg/kg·bw; APS2, 1400 mg/kg·bw; APS3, 2100 mg/kg·bw.
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Table 1. Influences of different doses of APSs on growth of M. albus.
Table 1. Influences of different doses of APSs on growth of M. albus.
ItemCONAPS1APS2APS3
Initial weight (g)25.28 ± 0.09 a25.44 ± 0.10 a25.28 ± 0.10 a25.06 ± 0.10 b
Final weight (g)34.07 ± 0.42 b39.61 ± 0.42 a40.11 ± 0.26 a34.28 ± 0.81 b
WG (%)34.80 ± 1.24 b55.68 ± 1.12 a58.70 ± 0.52 a36.82 ± 3.62 b
FCR2.80 ± 0.20 a2.01 ± 0.08 b2.01 ± 0.04 b2.92 ± 0.17 a
SR (%)95.56 ± 1.9397.78 ± 1.9297.78 ± 0.9695.00 ± 1.67
The means in the same column with different superscript letters are significantly different (p < 0.05). CON, 0 mg/kg·bw; APS1, 700 mg/kg·bw; APS2, 1400 mg/kg·bw; APS3, 2100 mg/kg·bw. Abbreviations: weight gain rate (WG), feed conversion ratio (FCR), survival rate (SR).
Table 2. Influences of different doses of APSs on whole blood indices of M. albus.
Table 2. Influences of different doses of APSs on whole blood indices of M. albus.
ItemCONAPS1APS2APS3
WBC (109/L)165.33 ± 16.19168.07 ± 5.63162.90 ± 7.11166.77 ± 6.21
RBC (1012/L)1.74 ± 0.091.76 ± 0.111.71 ± 0.041.76 ± 0.34
HGB (g/L)140.67 ± 2.08 b168.67 ± 10.26 a173.00 ± 8.72 a146.33 ± 4.93 b
HCT (%)21.70 ± 1.3521.53 ± 2.0722.70 ± 0.6622.43 ± 0.61
PLT (109/L)48.33 ± 1.5351.67 ± 3.2253.00 ± 4.3650.33 ± 7.37
MPV (fL)6.10 ± 0.266.23 ± 0.686.40 ± 0.366.13 ± 0.68
PDW (%)19.33 ± 0.5019.20 ± 0.4619.23 ± 0.3519.40 ± 0.36
Alphabetic superscripts denote significant intergroup variations (p < 0.05) within hematological indices. CON, 0 mg/kg·bw; APS1, 700 mg/kg·bw; APS2, 1400 mg/kg·bw; APS3, 2100 mg/kg·bw. Abbreviations: WBC (white blood cell), RBC (erythrocytes), HGB (hemoglobin), HCT (hematocrit), PLT (thrombocytes), MPV (platelet volume), PDW (platelet size heterogeneity).
Table 3. Influences of different doses of APSs on lipid metabolism of M. albus.
Table 3. Influences of different doses of APSs on lipid metabolism of M. albus.
ItemCONAPS1APS2APS3
TG (mmol/L)3.53 ± 1.25 a2.75 ± 0.08 ab2.00 ± 0.34 bc1.20 ± 0.05 c
CHO (mmol/L)3.69 ± 0.26 a3.41 ± 0.21 a3.47 ± 0.22 a2.53 ± 0.26 b
HDL (mmol/L)0.58 ± 0.06 c1.47 ± 0.11 a1.62 ± 0.16 a0.93 ± 0.15 b
LDL (mmol/L)1.56 ± 0.38 a1.49 ± 0.18 a1.13 ± 0.04 ab0.73 ± 0.09 b
Alphabetic superscripts denote significant intergroup variations (p < 0.05) within hematological indices. CON, 0 mg/kg·bw; APS1, 700 mg/kg·bw; APS2, 1400 mg/kg·bw; APS3, 2100 mg/kg·bw. Abbreviations: TG (triglyceride), CHO (cholesterol), HDL (high-density lipoprotein), LDL (low-density lipoprotein).
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MDPI and ACS Style

Wu, C.; Yang, H.; Yang, Y.; Yuan, Q.; Lv, W.; Ayana, G.U.; Li, M.; Su, D.; Zhou, W.; Zhang, Q. Dietary Supplementation of Astragalus Polysaccharides Modulates Growth Physiology, Metabolic Homeostasis, and Innate Immune Responses in Rice Field Eels (Monopterus albus). Fishes 2025, 10, 213. https://doi.org/10.3390/fishes10050213

AMA Style

Wu C, Yang H, Yang Y, Yuan Q, Lv W, Ayana GU, Li M, Su D, Zhou W, Zhang Q. Dietary Supplementation of Astragalus Polysaccharides Modulates Growth Physiology, Metabolic Homeostasis, and Innate Immune Responses in Rice Field Eels (Monopterus albus). Fishes. 2025; 10(5):213. https://doi.org/10.3390/fishes10050213

Chicago/Turabian Style

Wu, Chengcheng, Hang Yang, Yutong Yang, Quan Yuan, Weiwei Lv, Gelana Urgesa Ayana, Mingyou Li, Di Su, Wenzong Zhou, and Qinghua Zhang. 2025. "Dietary Supplementation of Astragalus Polysaccharides Modulates Growth Physiology, Metabolic Homeostasis, and Innate Immune Responses in Rice Field Eels (Monopterus albus)" Fishes 10, no. 5: 213. https://doi.org/10.3390/fishes10050213

APA Style

Wu, C., Yang, H., Yang, Y., Yuan, Q., Lv, W., Ayana, G. U., Li, M., Su, D., Zhou, W., & Zhang, Q. (2025). Dietary Supplementation of Astragalus Polysaccharides Modulates Growth Physiology, Metabolic Homeostasis, and Innate Immune Responses in Rice Field Eels (Monopterus albus). Fishes, 10(5), 213. https://doi.org/10.3390/fishes10050213

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