Synergistic pectin deconstruction is a prerequisite for mutualistic interactions between honeybee gut bacteria.

The honeybee gut microbiome is crucial for degrading diverse pollen glycans. Yet it is unclear how this process shapes the interactions among bacteria. Here, we demonstrate a conditional mutualistic interaction between strains of two honeybee gut bacteria Bifidobacterium asteroides and Gilliamella apicola. When co-occurring in vitro and in vivo, Bifidobacterium provides complementary demethylation service to promote Gilliamella growth on methylated homogalacturonan, an enriched polysaccharide of pectin. In exchange, Gilliamella shares digestive products with Bifidobacterium, through which a positive interaction is established. This positive interaction vanishes when Bifidobacterium is not required on a non-methylated diet. Results from biochemical and gene expression analyses combined with model simulation further suggest that the ratio change of the two major homogalacturonan breakdown products, galacturonic acid (GalA) and di-GalA, determines the bacterial interaction. This study unravels how glycan metabolism may shape the interactions between honeybee gut bacteria.

Biological Activity of Hybrid Vaterite-Pectin Microparticles Towards Bacteria E. coli and Human Neutrophils.

Interaction of microbiota with hybrid vaterite-pectin microparticles as an attractive multifunctional vehicle for mucosal delivery should not provoke inflammation. Our purpose was to study the reaction of bacteria E. coli strain Mg1655 and isolate SharL from a patient with Crohn disease on the cultivation with hybrid microparticles and vaterite, and the subsequent activation of neutrophils. Vaterite-pectin microparticles enhanced leakage of ATP from bacteria. For E. coli Mg1655, the concentration of DNA decreased, while intracellular ATP increased. For E. coli SharL, the intracellular ATP decreased with simultaneous growth of DNA. Bacteria and microparticles together did not enhance activation of neutrophils in comparison with the particles per se in the medium without serum and in comparison with bacteria in the medium supplemented with serum; microparticles did not reduce functional activity of neutrophils.

Polygalacturonic acid partially inhibits matrix metalloproteinases and dehydration in wounds.

BACKGROUND: Key wound environment parameters include pH, hydration, and the balance between tissue remodeling and deposition of new tissue. When prolonged inflammation is present, the proliferation phase of wound healing can be delayed because excessive protease production due to persistent inflammation can destroy newly formed tissue and prevent wounds from filling and reepithelializing. OBJECTIVE: To conduct an in vitro study of the ability of polygalacturonic acid (PG), a natural pectin derivative present in ripening fruit, to inhibit 3 destructive wound proteases and prevent dehydration in environments in which significant evaporation can occur. MATERIALS AND METHODS: In vitro enzyme inhibition assay kits were used to detect the ability of PG to inhibit key wound proteases matrix metalloproteinase (MMP)-2, MMP-9, and neutrophil elastase (NE). Transepidermal evaporative water loss from a polyvinyl alcohol skin substitute hydrogel was gravimetrically measured. RESULTS: PG could partially inhibit MMP-2 (>50% inhibition relative to negative controls), MMP-9 (>50% inhibition relative to negative controls), and NE (>25% inhibition relative to negative controls) and thereby potentially blunt some of the destructive effects of excess proteases where prolonged inflammation is present. In an in vitro transepidermal evaporative water loss assay, PG also helped retain moisture and inhibited dehydration (>25% reduction relative to negative controls). CONCLUSIONS: These findings suggest that PG can be a useful addition to ointments and dressings in wound care and warrants further in vivo testing.

Dietary Fiber's Physicochemical Properties and Gut Bacterial Dysbiosis Determine Fiber Metabolism in the Gut.

A fiber-rich diet is considered beneficial for gut health. An inflamed gut with a dysbiotic bacterial community can result in altered fiber metabolism depending on the fiber's physicochemical properties. This study examined the effect of fiber's physicochemical properties on fiber fermentation in the presence of healthy and colitis-associated bacteria. Sixteen fibers with different levels of solubility, complexity, and fermentation rate were used in in vitro fermentation with healthy human gut bacteria. Resistant maltodextrins (RMD), pectin (HMP), inulin (ChIn), and wheat bran (WB) were selected for fermentation using ulcerative colitis (UC)-associated bacteria to assess bacterial dysbiosis effect. UC-associated gut microbiota showed a significant reduction in α-and ß-diversity indices compared to healthy-associated microbiota. The differences in the gut microbiota composition and diversity between the donors resulted in decreased fermentation rates with UC-associated bacteria. Fiber fermentation metabolites, short-chain fatty acids (SCFA) and gas production were significantly lower in the presence of UC-associated bacteria for all four fibers tested. Overall, we conclude that dietary fiber properties and microbial dysbiosis are influential in fiber fermentation and metabolite production in the gut.

Exploring the potential of waste biomass-derived pectin and its functionalized derivatives for water treatment.

Environmental pollution remains a constant challenge due to the indiscriminate use of fossil fuels, mining activities, chemicals, drugs, aromatic compounds, pesticides, etc. Many emerging pollutants with no fixed standards for monitoring and control are being reported. These have adverse impacts on human life and the environment around us. This alarms the wastewater management towards developing materials that can be used for bulk water treatment and are easily available, low cost, non-toxic and biodegradable. Waste biomass like pectin is extracted from fruit peels which are a discarded material. It is used in pharmaceutical and nutraceutical applications but its application as a material for water treatment is very limited in literature. The scientific gap in literature review reports are evident with discussion only on pectin based hydrogels or specific pectin derivatives for some applications. This review focuses on the chemistry, extraction, functionalization and production of pectin derivatives and their applications in water treatment processes. Pectin functionalized derivatives can be used as a flocculant, adsorbent, nano biopolymer, biochar, hybrid material, metal-organic frameworks, and scaffold for the removal of heavy metals, ions, toxic dyes, and other contaminants. The huge quantum of pectin biomass may be explored further to strengthen environmental sustainability and circular economy practices.

Influences of different ultrasonic treatment intensities on the molecular chain conformation and interfacial behavior of sugar beet pectin.

In this study, the effects of different ultrasonic treatment intensities (57, 170, and 283 W/cm2) on the chemical composition, molecular chain characteristics, crystal structure, micromorphology, interfacial adsorption behavior and emulsifying properties of sugar beet pectin (SBP) were investigated. Ultrasonic treatment did not change the types of SBP monosaccharides, but it had impacts on their various monosaccharide contents. Moreover, the feruloylated, acetyl, and methoxy groups of SBP also undergo varying degrees of changes. The increase in ultrasonic treatment intensity led to transition in the molecular chain conformation of SBP from rigid semi-flexible chains to flexible chains, accompanied by modification in its crystal structure. Microstructural analysis of SBP confirmed the significant change in molecular chain conformation. Modified SBP could form an elastic interfacial film with higher deformation resistance on the oil-water interface. The SBP sample modified with 170 W/cm2 exhibited better emulsifying properties owing to its better interfacial adsorption behavior. Moreover, the emulsions prepared with modified SBP exhibited better stability capability under different environmental stresses (pH value, salt ion concentration, heating temperature and freeze-thaw treatment). The results revealed that the ultrasonic technology is useful to improve the emulsifying properties of SBP.

Natural variation of TBR confers plant zinc toxicity tolerance through root cell wall pectin methylesterification.

Zinc (Zn) is an essential micronutrient but can be cytotoxic when present in excess. Plants have evolved mechanisms to tolerate Zn toxicity. To identify genetic loci responsible for natural variation of plant tolerance to Zn toxicity, we conduct genome-wide association studies for root growth responses to high Zn and identify 21 significant associated loci. Among these loci, we identify Trichome Birefringence (TBR) allelic variation determining root growth variation in high Zn conditions. Natural alleles of TBR determine TBR transcript and protein levels which affect pectin methylesterification in root cell walls. Together with previously published data showing that pectin methylesterification increase goes along with decreased Zn binding to cell walls in TBR mutants, our findings lead to a model in which TBR allelic variation enables Zn tolerance through modulating root cell wall pectin methylesterification. The role of TBR in Zn tolerance is conserved across dicot and monocot plant species.

Anti-α-1,4-D-polygalacturonic acid antibodies as a new biomarker for juvenile idiopathic arthritis.

OBJECTIVE: Diagnosing juvenile idiopathic arthritis (JIA) is challenging. Our study aimed to investigate the clinical significance of anti-α-1,4-D-polygalacturonic acid (PGA) antibodies in JIA, focusing on their role in diagnosis and assessing disease activity. METHODS: In this prospective case-control study, we examined variations in serum levels of PGA-IgA and PGA-IgG among children with different types of JIA and healthy controls. Serum PGA-IgA and PGA-IgG levels were assessed concurrently in children with active and inactive JIA. RESULTS: This study included 126 patients diagnosed with JIA, 13 neonates, and 76 healthy children. Serum PGA-IgA and PGA-IgG levels were assessed, which revealed significant differences in PGA-IgA levels between various JIA subtypes and controls. An analysis of PGA-IgA levels in various JIA states revealed a statistically significant difference. Receiver operating characteristic (ROC) analysis demonstrated the robust predictive capability of PGA-IgA, with an AUC of 0.879 (p < 0.001), along with a specificity of 0.842 and sensitivity of 0.848. CONCLUSION: Increased levels of anti-PGA antibodies, particularly PGA-IgA, were significantly associated with JIA. PGA-IgA may serve as a sensitive biomarker for disease activity in JIA and could potentially aid in the diagnosis of JIA. Key Points • This study found a significant correlation between blood levels of PGA-IgA and juvenile idiopathic arthritis (JIA), which may provide valuable diagnostic insights. • PGA-IgA shows potential as a sensitive biomarker for the assessment of disease activity in JIA patients, helping to determine disease activity.

Structure characterization and gelling properties of RG-I-enriched pectins extracted from citrus peels using four different methods.

To facilitate the application of rhamnogalacturonan-I (RG-I)-enriched pectins (RGPs) as novel, healthy, and gelling food additives, this study compared the structural characteristics and gelling properties of RGPs extracted from citrus peel via four methods (alkali: AK, high-temperature/pressure: TP, citric acid: CA, and enzyme-assisted: EA extractions). AK and CA yielded pectins with the highest RG-I proportions (54.8 % and 51.9 %, respectively) by disrupting the homogalacturonan region; TP and EA increased the RG-I proportions by ~10 %. Among the four methods, AK induced the lowest degree of esterification (DE) (6.7 %) and longer side chains that form strong entanglement, contributing to its highest gel hardness. The relatively low DE (18.5 %) of CA RGP facilitated stable gel formation. Notably, its highly branched RG-I region afforded more intramolecular hydrophobic interactions, making a more highly cross-linked gel network of better gel resilience. In contrast, TP induced the highest DE (57 %) and curved molecular chains; it inhibited Ca2+ binding, entanglement, and intramolecular hydrophobic interactions, and thus no gel formed. EA RGP was associated with the lowest molecular size, rendering it more difficult for Ca2+ to form links, which resulted no gel. These findings offer insights into the relationship among the extraction methods, molecular structures, and gelling properties of RGPs.

The detrimental role of galectin-3 and endoplasmic reticulum stress in the cardiac consequences of myocardial ischemia in the context of obesity.

The association between cardiac fibrosis and galectin-3 was evaluated in patients with acute myocardial infarction (MI). The role of galectin-3 and its association with endoplasmic reticulum (ER) stress activation in the progression of cardiovascular fibrosis was also evaluated in obese-infarcted rats. The inhibitor of galectin-3 activity, modified citrus pectin (MCP; 100 mg/kg/day), and the inhibitor of the ER stress activation, 4-phenylbutyric acid (4-PBA; 500 mg/kg/day), were administered for 4 weeks after MI in obese rats. Overweight-obese patients who suffered a first MI showed higher circulating galectin-3 levels, higher extracellular volume, and LV infarcted size, as well as lower E/e'ratio and LVEF compared with normal-weight patients. A correlation was observed between galectin-3 levels and extracellular volume. Obese-infarcted animals presented cardiac hypertrophy and reduction in LVEF, and E/A ratio as compared with control animals. They also showed an increase in galectin-3 gene expression, as well as cardiac fibrosis and reduced autophagic flux. These alterations were associated with ER stress activation characterized by enhanced cardiac levels of binding immunoglobulin protein, which were correlated with those of galectin-3. Both MCP and 4-PBA not only reduced cardiac fibrosis, oxidative stress, galectin-3 levels, and ER stress activation, but also prevented cardiac functional alterations and ameliorated autophagic flux. These results show the relevant role of galectin-3 in the development of diffuse fibrosis associated with MI in the context of obesity in both the animal model and patients. Galectin-3 in tandem with ER stress activation could modulate different downstream mechanisms, including inflammation, oxidative stress, and autophagy.

Salt stress alters the cell wall components and structure in Miscanthus sinensis stems.

Miscanthus is a perennial grass suitable for the production of lignocellulosic biomass on marginal lands. The effects of salt stress on Miscanthus cell wall composition and its consequences on biomass quality have nonetheless received relatively little attention. In this study, we investigated how exposure to moderate (100 mM NaCl) or severe (200 mM NaCl) saline growing conditions altered the composition of both primary and secondary cell wall components in the stems of 15 Miscanthus sinensis genotypes. The exposure to stress drastically impacted biomass yield and cell wall composition in terms of content and structural features. In general, the observed compositional changes were more pronounced under severe stress conditions and were more apparent in genotypes with a higher sensitivity towards stress. Besides a severely reduced cellulose content, salt stress led to increased pectin content, presumably in the form of highly branched rhamnogalacturonan type I. Although salt stress had a limited effect on the total lignin content, the acid-soluble lignin content was strongly increased in the most sensitive genotypes. This effect was also reflected in substantially altered lignin structures and led to a markedly reduced incorporation of syringyl subunits and p-coumaric acid moieties. Interestingly, plants that were allowed a recovery period after stress ultimately had a reduced lignin content compared to those continuously grown under control conditions. In addition, the salt stress-induced cell wall alterations contributed to an improved enzymatic saccharification efficiency.

Characterization of a novel sulfated-rhamnoglucuronan isolated from Korean seaweed Ulva pertusa and its efficacy for treatment of inflammatory bowel disease in mice.

This study aimed to isolate Ulva pertusa polysaccharide (UPP), which elicits anti-inflammatory bowel disease (IBD) effects, from the Korea seaweed U. pertusa and identify its structure. Firstly, UPP was isolated from U. pertusa using hydrothermal extraction and ethanol precipitation. UPP is a novel polysaccharide that exhibits unique structural features such as 3-sulfated rhamnose, glucuronic acid, iduronic acid, and 3-sulfated xylose, which are repeated in 1,4-glycosidic bonds. Prophylactic oral administration of UPP in mice with dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) suppressed the levels of inflammatory cytokines and MAPK- and NF-κB-related factors in the serum and colon tissue. Tight junction (TJ)-related factors such as occludin, claudin-1, and mucin were effectively augmented by UPP in the colon tissue. In addition, UPP administration prevented the DSS treatment-led cecal short chain fatty acid imbalance, and this effect was most evident for propionic acid. In conclusion, UPP isolated from the Korean U. pertusa demonstrates potent anti-IBD activity. Characterization of this ulvan revealed its unique structure. Moreover, its efficacy may be associated with its anti-inflammatory effects and regulation of gut microbiota and TJ proteins. Thus, this study provides new insights into the biological effects of UPP in IBD.

Arabinoxylo-oligosaccharides production from unexploited agro-industrial sesame (Sesamum indicum L.) hulls waste.

This work demonstrates that sesame (Sesamum indicum L.) hull, an unexploited food industrial waste, can be used as an efficient source for the extraction of hemicellulose and/or pectin polysaccharides to further obtain functional oligosaccharides. Different polysaccharides extraction methods were surveyed including alkaline and several enzymatic treatments. Based on the enzymatic release of xylose, arabinose, glucose, and galacturonic acid from sesame hull by using different enzymes, Celluclast®1.5 L, Pectinex®Ultra SP-L, and a combination of them were selected for the enzymatic extraction of polysaccharides at 50 °C, pH 5 up to 24 h. Once the polysaccharides were extracted, Ultraflo®L was selected to produce arabinoxylo-oligosaccharides (AXOS) at 40 °C up to 24 h. Apart from oligosaccharides production from extracted polysaccharides, alternative approaches for obtaining oligosaccharides were also explored. These were based on the analysis of the supernatants resulting from the polysaccharide extraction, alongside a sequential hydrolysis performed with Celluclast®1.5 L and Ultraflo®L of the starting raw sesame hull. The different fractions obtained were comprehensively characterized by determining low molecular weight carbohydrates and monomeric compositions, average Mw and dispersity, and oligosaccharide structure by MALDI-TOF-MS. The results indicated that sesame hull can be a useful source for polysaccharides extraction (pectin and hemicellulose) and derived oligosaccharides, especially AXOS.

Regulations of Citrus Pectin Oligosaccharide on Cholesterol Metabolism: Insights from Integrative Analysis of Gut Microbiota and Metabolites.

(1) Background: Recently, academic studies are demonstrating that the cholesterol-lowering effects of pectin oligosaccharides (POSs) are correlated to intestinal flora. However, the mechanisms of POS on cholesterol metabolisms are limited, and the observations of intestinal flora are lacking integrative analyses. (2) Aim and methods: To reveal the regulatory mechanisms of POS on cholesterol metabolism via an integrative analysis of the gut microbiota, the changes in gut microbiota structure and metabolite composition after POS addition were investigated using Illumina MiSeq sequencing and non-targeted metabolomics through in vitro gut microbiota fermentation. (3) Results: The composition of fecal gut flora was adjusted positively by POS. POS increased the abundances of the cholesterol-related bacterial groups Bacteroidetes, Bifidobacterium and Lactobacillus, while it decreased conditional pathogenic Escherichia coli and Enterococcus, showing good prebiotic activities. POS changed the composition of gut microbiota fermentation metabolites (P24), causing significant changes in 221 species of fermentation metabolites in a non-targeted metabolomics analysis and promoting the production of short-chain fatty acids. The abundances of four types of cholesterol metabolism-related metabolites (adenosine monophosphate, cyclic adenosine monophosphate, guanosine and butyrate) were significantly higher in the P24 group than those in the control group without POS addition. (4) Conclusion: The abovementioned results may explain the hypocholesterolemic effects of POS and promotion effects on cholesterol efflux of P24. These findings indicated that the potential regulatory mechanisms of citrus POS on cholesterol metabolism are modulated by cholesterol-related gut microbiota and specific metabolites.

Tuning bio-aerogel properties. Part 3: Exploring silica-pectin composite aerogels for drug delivery.

The release of the model drug theophylline from silica-pectin aerogels was investigated. The composite aerogels were prepared via impregnation of pectin alcogels with silica sol, followed by in situ silica gelation and drying with supercritical CO2. The structural and physico-chemical properties of the aerogels were tuned via the preparation conditions (type of silica sol, calcium crosslinking of pectin or not). Theophylline was loaded via impregnation and its release into simulated gastric fluid was studied during 1 h followed by release into simulated intestinal fluid. The swelling, mass loss and theophylline release behavior of the composites were analyzed and correlated with material properties. It followed that only aerogels prepared with calcium-crosslinked pectin and polyethoxydisiloxane were stable in aqueous systems, exhibiting a slow theophylline release governed by near-Fickian diffusion.

Bioaccessibility of iron in developed pectin iron complex using Citrus limon Burm F. peels subjected to in-vitro gastro-pancreatic digestion.

Pectin from the citrus peel waste has novel applications in food and biomedical industries. The present work focused on addressing iron deficiency, which is a global health concern, by developing a functional ingredient using pectin extracted from Assam lemon (Citrus limon Burm. F) and supplementing iron via the pectin­iron complex (PIC). Extracted pectin was incubated with iron chloride hexahydrate (0.90-1.80 mM) for 180 h to optimize the complexation conditions, with the optimal concentration being 1.36 mM. The iron bioavailability and its absorption in the PIC was assessed using in-vitro simulation digestion and Caco-2 cell monolayers. The bioaccessible form of iron in the developed PIC during the intestinal phase was 5.34 ± 0.16%, which was negligible in pectin. The absorption of bioaccessible iron in the PIC was found to be 2.93 ± 0.03%. The results demonstrated that PIC could reduce iron deficiency and increase fibre intake, leading to several health benefits.

Enhanced stability of encapsulated lemongrass essential oil in chitosan-gelatin and pectin-gelatin biopolymer matrices containing ZnO nanoparticles.

The use of essential oils is widespread in various fields such as pharmacy, pest control, and active packaging. However, their instability and short-term effects require methods to enhance their durability and effectiveness. Encapsulation in biopolymer matrices appears to be a promising approach due to the environmental safety and cost-effectiveness of such formulations. In this study, different oil-in-water emulsions were prepared by mixing chitosan-gelatin (C-G) or pectin-gelatin (P-G) solutions with lemongrass essential oil (LG). ZnO NPs were used as an additional active component. Encapsulation in biopolymer matrices resulted in stable emulsions with a significantly slower release of LG, and ZnO NPs further suppressed LG release, particularly in the P-G emulsion. They also contributed to the stability of the emulsions and a decrease in the average droplet size of LG. Furthermore, the presence of LG and ZnO NPs improved the smoothness of the films prepared from the emulsions and dispersions using the casting technique. SEM/EDS analysis confirmed the homogeneous distribution of ZnO NPs in both C-G and P-G films. By adjusting the type and content of the biopolymers and NPs, such emulsions could be effectively utilized in various applications where controlled release of active components is required.

Structural elucidation a complex galactosyl and glucosyl-rich pectin from the pericarp of immature fruits of Juglans mandshurica Maxim.

A glucosyl-rich pectin, JMMP-3 (Mw, 2.572 × 104 g/mol, O-methyl % = 3.62%), was isolated and purified from the pericarp of the immature fruit of Juglans mandshurica Maxim. (QingLongYi). The structure of JMMP-3 was studied systematically by infrared spectroscopy, monosaccharide compositions, methylation analysis, partial acid hydrolysis, and 1/2D-NMR. The backbone of JMMP-3 possessed a smooth region (→ 4GalA1 →) and a hairy region (→ 4GalA1 → 2Rha1 →) with a molar ratio of 2: 5. The substitution of four characteristic side chains (R1-R4) occurs at C-4 of → 2,4)-α-Rhap-(1→, where R1 is composed of → 5)-α-Araf-(1→, R2 is composed of → 4)-ß-Galp-(1 → and ß-Galp-(1→, R3 is composed of α-Glcp-(1→, →4)-α-Glcp-(1 → and → 4,6)-α-Glcp-(1→, and R4 is composed of → 5)-α-Araf-(1→, ß-Galp-(1→, → 4)-ß-Galp-(1→, → 3,4)-ß-Galp-(1→, → 4,6)-ß-Galp-(1 → and → 2,4)-ß-Galp-(1 → . In addition, the antitumor activity of JMMP-3 on HepG2 cells was preliminarily investigated.

Adsorption performance and mechanism of pectin modified with ß-cyclodextrin for Zn2+ and Cu2.

Removing heavy metals from aqueous solutions has drawn more and more attentions these years because of their serious global health challenge to human society. To develop an adsorbent with green, stable and high-efficiency for adsorption of heavy metals, pectin ß-cyclodextrin composite was successfully prepared and used for Zn2+ and Cu2+ adsorption for the first time. Various variables that influence the adsorption performance were explored, and the optimal adsorption conditions were determined. According to the pseudo-second-order kinetic model, the adsorption process of Zn2+ and Cu2+ by the adsorbent was mainly chemical adsorption. The adsorbent adsorption process was an exothermic and non-spontaneous process. According to the Langmuir isotherm model, the maximum adsorption capacity was 12.51 ± 0.33 and 24.98 ± 0.23 mg/g for Zn2+ and Cu2+, respectively. The FTIR, EDX and XPS results revealed that the main mechanisms of removing pollutants by adsorbent were ion exchange and coordination. In addition, electrostatic attraction and chelation were present in the adsorption process. After five adsorption desorption cycles, the pectin ß-cyclodextrin composite adsorbent still exhibited adsorption and regeneration capabilities. This study provides a low-cost, effective and simple method for preparation of modified pectin, which has excellent application potential in the removal of heavy metal ions from wastewater.

Reversible ON- and OFF-switch receptors Clec4G and Rab1A reveal the hormetic effects of a pectin polysaccharide in Aralia elata (Miq.) Seem.

BACKGROUND: Numerous studies indicate that natural polysaccharides have immune-enhancing effects as a host defense potentiator. Few reports are available on hormetic effects of natural polysaccharides, and the underlying mechanisms remain unclear. PURPOSE: AELP-B6 (arabinose- and galactose-rich pectin polysaccharide) from Aralia elata (Miq.) Seem was taken as a case study to clarify the potential mechanism of hormetic effects of natural polysaccharides. METHODS: The pharmacodynamic effect of AELP-B6 was verified by constructing the CTX-immunosuppressive mouse model. The hormetic effects were explored by TMT-labeled proteomics, energy metabolism analysis, flow cytometry and western blot. The core-affinity target of AELP-B6 was determined by pull down, nanoLC-nanoESI+-MS, CETSA, immunoblot and SPR assay. The RAW264.7Clec4G-RFP and RAW264.7Rab1A-RFP cell lines were simultaneously constructed to determine the affinity difference between AELP-B6 and targets by confocal laser scanning live-cell imaging. Antibody blocking assays were further used to verify the mechanism of hormetic effects. RESULTS: AELP-B6 at low and medium doses may maintain the structural integrity of thymus and spleen, increase the concentrations of TNF-α, IFN-γ, IL-3 and IL-8, and alleviate CTX-induced reduction of immune cell viability in vivo. Proteomics and energy metabolism analysis revealed that AELP-B6 regulate HIF-1α-mediated metabolic programming, causing Warburg effects in macrophages. AELP-B6 at low and medium doses promoted the release of intracellular immune factors, and driving M1-like polarization of macrophages. As a contrast, AELP-B6 at high dose enhanced the expression levels of apoptosis related proteins, indicating activation of the intrinsic apoptotic cascade. Two highly expressed transmembrane proteins in macrophages, Clec4G and Rab1A, were identified as the primary binding targets of AELP-B6 which co-localized with the cell membrane and directly impacted with immune cell activation and apoptosis. AELP-B6 exhibits affinity differences with Clec4G and Rab1A, which is the key to the hormetic effects. CONCLUSION: We observed hormesis of natural polysaccharide (AELP-B6) for the first time, and AELP-B6 mediates the hormetic effects through two dose-related targets. Low dose of AELP-B6 targets Clec4G, thereby driving the M1-like polarization via regulating NF-κB signaling pathway and HIF-1α-mediated metabolic programming, whereas high dose of AELP-B6 targets Rab1A, leading to mitochondria-dependent apoptosis.