The inhibitory effect of phosphorylated Codonopsis pilosula polysaccharide on autophagosomes formation contributes to the inhibition of duck hepatitis A virus replication

Anti-virus activity and mechanisms of natural polysaccharides from medicinal herbs

There has been a sudden increase in viral diseases, such as coronavirus disease 2019 (COVID-19), causing significant harm to human and animal well-being, as well as economic development. Medicinal herbs, with a history of thousands of years in clinical use, contain versatile polysaccharides as one of their primary compounds. This review offers an overview of the antiviral effects of polysaccharides from medicinal herbs on viruses in humans, poultry, swine and aquaculture in recent years. The mechanism of these antiviral polysaccharides, involved in hindering various stages of the viral life cycle thereby blocking virus infection, is summarized. The review also explores other underlying mechanisms of antiviral effects, such as enhancing the immune response, regulating inflammatory reactions, balancing gut flora, reducing oxidative stress, and suppressing apoptosis through various corresponding signaling pathways. The structure-function relationships discussed in this article also aid in understanding the antiviral mechanism of natural polysaccharides, indicating the need for more in-depth research and analysis. Natural polysaccharides from medicinal herbs have emerged as valuable resources in the fight against viral infections, exhibiting high effectiveness. This review emphasizes the promising role of polysaccharides from medicinal herbs as potential candidates for blocking viral infections in humans and animals.

Progress in phosphorylation of natural products

Natural medicines are a valuable resource for the development of new drugs. However, factors such as low solubility and poor bioavailability of certain constituents have hindered their efficacy and potential as pharmaceuticals. Structural modification of natural products has emerged as an important research area for drug development. Phosphorylation groups, as crucial endogenous active groups, have been extensively utilized for structural modification and development of new drugs based on natural molecules. Incorporating phosphate groups into natural molecules not only enhances their stability, bioavailability, and pharmacological properties, but also improves their biological activity by altering their charge, hydrogen bonding, and spatial structure. This review summarizes the phosphorylation mechanism, modification approaches, and biological activity enhancement of natural medicines. Notably, compounds such as polysaccharides, flavonoids, terpenoids, anthraquinones, and coumarins exhibit increased antioxidation, anticancer, antiviral, immune regulatory, Antiaging, enzyme inhibition, bacteriostasis, liver protection, and lipid-lowering effects following phosphorylation modification.

Modulation of cyclophosphamide-induced immunosuppression and intestinal flora in broiler by deep eutectic solvent extracted polysaccharides of Acanthopanax senticosus

Introduction

The aim of this experiment was to investigate the modulation effect of Acanthopanax senticosus polysaccharide (ASPS-PD) extracted with deep eutectic solvent on cyclophosphamide-induced immunosuppression in broilers and its modulation of the gut microbiota of broilers.

Methods

The 108 one-day-old broilers were divided into six groups, including the control group, the Cyclophosphamide (CY) model group, the ASPS-PD control group, the ASPA-PD high and low dose groups and the Astragalus polysaccharide group. Body weight, feed intake, feed conversion ratio, and immune organ index of broilers at 7, 14, and 21 days were determined; IL-2, IFN-γ, and lgG1 levels were determined by enzyme-linked immunosorbent assay (ELISA); Broiler caeca feces were analyzed by amplification and 16S rRNA sequencing.

Results

The results showed that ASPS-PD can restore growth performance, increase immune organ index and improve serum cytokine levels of IL-2 and IFN-γ and immunoglobulin lgG1 levels in CY-treated broilers. The analysis of cecum flora showed that ASPS-PD can promote the proliferation of beneficial bacteria and reduce the number of harmful bacteria, regulating intestinal flora.

Discussion

Therefore, ASPA-PD may be a potential novel immunomodulator to ameliorate CY-induced immunosuppression and intestinal flora dysregulation in broiler.

Eco-Friendly and Efficient Extraction of Polysaccharides from Acanthopanax senticosus by Ultrasound-Assisted Deep Eutectic Solvent

A green extraction method was developed using deep eutectic solvent extraction for the polysaccharide from Acanthopanax senticosus (A. senticosus). Among the eight types of DES prepared, the DES with a ratio of 1:4 L-malic acid to L-proline was found to be a suitable extraction solvent based on the extraction efficiency. The extraction parameters were optimized by Plackett-Burman and response surface methodology (RSM). The best extraction conditions were found for L-malic acid. Under the conditions of an L-malic acid/L-proline ratio of 1:4, ultrasonic power of 240 W, material-liquid ratio of 31.068 g/mL, water content of 32.364%, extraction time of 129.119 min, and extraction temperature of 60 °C, the extraction rate of A. senticosus polysaccharides was 35.452 ± 0.388 mg-g-1. This rate was higher than that of polysaccharides obtained by hot water extraction (13.652 ± 0.09 mg-g-1). The experimental results were best fitted by the quasi-secondary kinetic model when compared to two other kinetic models. Electron microscopic observations showed that DESs were more destructive to plant cells. The polysaccharide extracted from DESs had more monosaccharide components, a lower molecular weight, a higher antioxidant capacity, and superior anti-glycation activity compared to polysaccharides extracted from water (ASPS-PW). This study demonstrates the effectiveness of DESs in obtaining polysaccharides from A. senticosus.

Portulaca oleracea L. Polysaccharide Inhibits Porcine Rotavirus In Vitro

Diarrhea is one of the most common causes of death in young piglets. Porcine rotavirus (PoRV) belongs to the genus Rotavirus within the family Reoviridae, and is considered to be the primary pathogen causing diarrhea in piglets. Portulaca oleracea L. (POL) has been reported to alleviate diarrhea and viral infections. However, the antiviral effect of Portulaca oleracea L. polysaccharide (POL-P), an active component of POL, on PoRV infection remains unclear. This study demonstrated that the safe concentration range of POL-P in IPEC-J2 cells is 0-400 μg/mL. POL-P (400 μg/mL) effectively inhibits PoRV infection in IPEC-J2 cells, reducing the expression of rotavirus VP6 protein, mRNA and virus titer. Furthermore, on the basis of viral life cycle analysis, we showed that POL-P can decrease the expression of PoRV VP6 protein, mRNA, and virus titer during the internalization and replication stages of PoRV. POL-P exerts antiviral effects by increasing IFN-α expression and decreasing the expression levels of TNF-α, IL-6, and IL-10 inflammatory factors. Overall, our study found that POL-P is a promising candidate for anti-PoRV drugs.

Plant type II arabinogalactan: Structural features and modification to increase functionality

Type II arabinogalactans (AGs) are a highly diverse class of plant polysaccharides generally encountered as the carbohydrate moieties of certain extracellular proteoglycans, the so-called arabinogalactan-proteins (AGPs), which are found on plasma membranes and in cell walls. The basic structure of type II AG is a 1,3-β-D-galactan main chain with 1,6-β-D-galactan side chains. The side chains are further decorated with other sugars such as α-l-arabinose and β-d-glucuronic acid. In addition, AGs with 1,6-β-D-galactan as the main chain, which are designated as 'type II related AG' in this review, can also be found in several plants. Due to their diverse and heterogenous features, the determination of carbohydrate structures of type II and type II related AGs is not easy. On the other hand, these complex AGs are scientifically and commercially attractive materials whose structures can be modified by chemical and biochemical approaches for specific purposes. In the current review, what is known about the chemical structures of type II and type II related AGs from different plant sources is outlined. After that, structural analysis techniques are considered and compared. Finally, structural modifications that enhance or alter functionality are highlighted.

Progress of Studies on Plant-Derived Polysaccharides Affecting Intestinal Barrier Function in Poultry

As natural bioactive components, plant-derived polysaccharides have many biological functions, such as anti-inflammatory, antioxidant, anticoccidial, and immunity regulation, and have been widely used in poultry production. In this review paper, firstly, the sources and structures of plant-derived polysaccharides are reviewed; secondly, the effects of plant-derived polysaccharides on the intestinal microbiome, permeability, morphology and immune function of poultry are summarized; thirdly, the potential molecular regulation mechanism of plant-derived polysaccharides on the intestinal barrier function of poultry was preliminarily analyzed. The review paper will bring a basis for the scientific utilization of plant-derived polysaccharides in the poultry industry.

Structural characterization, antioxidant activity and anti-inflammatory of the phosphorylated polysaccharide from Pholiota nameko

In this study, a novel polysaccharide (SPN) was extracted by high-temperature pressure method and purified by a DEAE-52 column and a Sephadx G-100 gel column. PPN was obtained after phosphorylation of SPN. The differences of structural features, antioxidant activity, and anti-inflammatory effect of the two polysaccharides were investigated by chemical methods and RAW 264.7 cell model. SPN (Mw = 15.8 kDa) and PPN (Mw = 27.7 kDa) are an acidic polysaccharide with β-pyranose configuration, mainly containing rhamnose, mannose, glucose, arabinose, and galacose. FI-IR, NMR, and SEM spectra showed phosphorylation of SPN changed its structure. In methylation analysis, the major chains of SPN and PPN were 1,4-linked Glcp, 1,6-linked Galp, 1,2-linked Rhap, and 1.6-linked Manp with terminals of t-linked Glcp, t-linked Araf. The side chain of SPN was 1,4,6-linked Galp, 1,2,5-linked Araf, while the side chain of PPN was 1,4,6-linked Galp, 1,2,4-linked Glcp. In antioxidant activity experiments, the free radical scavenging rate of PPN was stronger than that of SPN. Also, PPN always has better anti-inflammatory on RAW 264.7 cells induced by LPS than that of SPN in same concentration, and it plays an anti-inflammatory role by inhibiting PI3K/AKT/mTOR pathway. The results indicated polysaccharide could significantly improve its antioxidant and anti-inflammatory function after phosphorylation. This study provides a potentially antioxidant and anti-inflammatory health food and drug.

Synthesis and application of phosphorylated saccharides in researching carbohydrate-based drugs

Phosphorylated saccharides are valuable targets in glycochemistry and glycobiology, which play an important role in various physiological and pathological processes. The current research on phosphorylated saccharides primarily focuses on small molecule inhibitors, glycoconjugate vaccines and novel anti-tumour targeted drug carrier materials. It can maximise the pharmacological effects and reduce the toxicity risk caused by nonspecific off-target reactions of drug molecules. However, the number and types of natural phosphorylated saccharides are limited, and the complexity and heterogeneity of their structures after extraction and separation seriously restrict their applications in pharmaceutical development. The increasing demands for the research on these molecules have extensively promoted the development of carbohydrate synthesis. Numerous innovative synthetic methodologies have been reported regarding the continuous expansion of the potential building blocks, catalysts, and phosphorylation reagents. This review summarizes the latest methods for enzymatic and chemical synthesis of phosphorylated saccharides, emphasizing their breakthroughs in yield, reactivity, regioselectivity, and application scope. Additionally, the anti-bacterial, anti-tumour, immunoregulatory and other biological activities of some phosphorylated saccharides and their applications were also reviewed. Their structure-activity relationship and mechanism of action were discussed and the key phosphorylation characteristics, sites and extents responsible for observed biological activities were emphasised. This paper will provide a reference for the application of phosphorylated saccharide in the research of carbohydrate-based drugs in the future.

A monitoring survey and health risk assessment for pesticide residues on Codonopsis Radix in China

In recent years, the safety of Codonopsis Radix (CR) has attracted considerable attention. Pesticide residues is an important index to evaluate the safety of CR. The purpose of this study was to monitor pesticide residues in 164 batches of CR in China and assess dietary risk assessment. Firstly, a combined method of QuEChERS-GC–MS/MS and QuEChERS-LC–MS/MS was established for determination of 155 pesticide residues in CR. Second, 155 Pesticide residues in 3 CR cultivars from Gansu, Shanxi, Hubei, Guizhou and Chongqing were determined by this method. Finally, the risk score of pesticide residues in CR was evaluated, and the dietary health risk was evaluated based on the pesticide residues in CR. The results demonstrated that one or more pesticide residues were detected in 39 batches (23.78%) of 164 batches of CR. Of the 155 pesticide residues, 20 were detected. The most frequently detected pesticide residue was dimethomorph with a detection rate of 5.49%. Risk scores showed that 6 pesticides were at higher risk. Risk assessment based on the hazard quotient/hazard index (HQ/HI) approach revealed that exposure to pesticide residues which detected in CR were far below levels that might pose a health risk.

The Effect and Mechanism of New Processing Method of Codonopsis pilosula on Endocrine Physique Index in Rats

Objective. To explore the effect and mechanism of a new processing method of Codonopsis pilosula (CP) on the endocrine physique index in rats. Methods. The rats were randomly assigned into the control group, model group, CP group (3.75 g/kg crude drug), rice-fried CP group (3.75 g/kg crude drug), and honey-roasted CP group (3.75 g/kg), with 10 rats in each group. All rats were gavaged according to the body weight of 1 mL/100 g every morning for 3 weeks. The water extracts of different processed products of CP were given to the drug group, the blank group, and the model group which were given the same volume of normal saline during the experiment. The model group and each administration group were fed every other day and drank freely for 21 days, during which the weight was weighed every 2 days. The changes of the organ index; the contents of cyclic adenosine monophosphate (cAMP), cyclic guanosine monophosphate (cGMP), adrenocorticotropic hormone (ACTH), and cortisol (Cor); and the activity of sodium and potassium adenosine triphosphate (Na+K+-ATP) were measured by enzyme-linked immunosorbent assay (ELISA). The expression of aquaporin-1 (AQP1) and aquaporin-2 (AQP2) mRNA was detected by RT-PCR. Results. Effect on the organ index: the organ index of the control group, CP group, rice-fried group, and honey moxibustion group was higher compared to that of the model group, and the organ index of the honey moxibustion group was the highest ( $P<0.05$ ). The level of cAMP and the ratio of cAMP/cGMP in the model group were significantly higher compared to those of the control group ( $P<0.05$ ); CGMP in the model group decreased significantly ( $P<0.05$ ). Compared with the model group, the level of cAMP in the CP group, rice-fried group, and honey moxibustion group decreased significantly, while the ratio of cGMP and cAMP/cGMP increased significantly ( $P<0.05$ ). Compared with the CP group, rice-fried group, and honey moxibustion group, the level of cAMP and the ratio of cAMP/cGMP in the honey moxibustion group were lower compared to those in the other two groups, and the ratio of cGMP in the honey moxibustion group was higher compared to that in the other two groups ( $P<0.05$ ). The contents of ACTH and Cor in the model group were significantly higher compared to those in the control group ( $P<0.05$ ). Compared with the model group, the contents of ACTH and Cor in the CP group, rice-fried group, and honey moxibustion group were significantly lower compared to those in the model group ( $P<0.05$ ). Compared with the CP group, rice-fried group, and honey moxibustion group, the contents of ACTH and Cor in the honey moxibustion group were higher compared to those in the other two groups ( $P<0.05$ ). The content of the Na+K+-ATP enzyme in the model group was significantly higher compared to that in the control group ( $P<0.05$ ). Compared with the model group, the content of the Na+K+-ATP enzyme in the CP group, rice-fried group, and honey moxibustion group decreased significantly ( $P<0.05$ ). Compared with the CP group, rice-fried group, and honey moxibustion group, the content of the Na+K+-ATP enzyme in the honey moxibustion group was higher compared to that in the other two groups ( $P<0.05$ ). The expression of AQP1 and AQP2 mRNA in the kidney tissue of the kidney yin deficiency model group was significantly higher compared to that of the control group ( $P<005$ ). Compared with the model group, the expression levels of AQP1 and AQP2 mRNA in the renal tissue of rats in the CP group, rice-fried group, and honey moxibustion group decreased in different degrees ( $P<0.05$ ). There was no statistical difference between the CP group, rice stir-frying group, and honey moxibustion group. Conclusion. This study proves that the new processing method of CP can improve the endocrine physique index of rats, enhance their organ quality, and regulate the disorder of water metabolism in kidney yin deficiency syndrome and has a certain therapeutic effect on kidney yin deficiency syndrome. Different new processing methods of CP have different effects on promoting endocrine physique indexes of rats. It is concluded that honey-roasted CP has the best effect on promoting spleen deficiency, which may be through glucose metabolism, amino acid metabolism, and nucleotide metabolism, increasing ATP energy metabolism, so as to strengthen the symptoms of spleen deficiency in rats. The experimental data of this study indicate that the effect of honey-roasted CP is better compared to that of other processed products, which provides an experimental basis for the rational clinical application of the new processed products.

Codonopsis pilosula polysaccharide attenuates Escherichia coli-induced acute lung injury in mice

Acute lung injury (ALI) is an inflammatory lung disease could be caused by bacterial infection. Lipopolysaccharide (LPS), a prototype pathogen-associated molecular pattern (PAMP) from gram-negative bacteria such as Escherichia coli...

The lysine at position 151 of the duck hepatitis A virus 1 2C protein is critical for its NTPase activities

The duck hepatitis A virus 1 (DHAV-1) 2C protein was predicted to be a superfamily III helicase member and includes nucleotide binding (NTB) and putative RNA helicase activity motifs. To study whether DHAV-1 2C protein has NTB activity, we expressed DHAV-1 2C protein with maltose binding protein (MBP) to solve its poor solubility in a prokaryotic expression system. We showed that the DHAV-1 2C protein has nucleoside triphosphatase (NTPase) activity by measuring the released phosphate. The NTPase of the DHAV-1 2C protein is Mg²⁺ indispensable and affected by other biochemical characteristics such as Mn²⁺, Ca²⁺, Zn²⁺, Na⁺ and pH. Guanidine hydrochloride (GdnHCl), a potent inhibitor of viral RNA replication, inhibited ATPase activity of the DHAV-1 2C protein in a dose-dependent manner. Finally, we constructed three mutants to identify the key site for the ATPase activity of the DHAV-1 2C protein. These results indicate that lysine at position 151 of the DHAV-1 2C protein is very important for NTPase activity. Here, we demonstrated and partially characterized that the DHAV-1 2C protein has NTPase activity and showed that mutation of the lysine in the conserved Walker A impairs that activity. The results serve to confirm what is readily predicted from previous work on picornavirus 2C proteins. It also provides a basis for further study of the 2C protein and the function of NTPase activity on the viral life cycle.

Preparation, structure and activity of polysaccharide phosphate esters

Polysaccharides have anti-virus, anti-cancer, anti-oxidation, immune regulation, hypoglycemia and other biological activities. Because of their safety, fewer side effects and other advantages, polysaccharides are considered as ideal raw materials in food and drugs. The biological activity of polysaccharides can be improved by structural modification (such as sulfation, carboxymethylation, phosphorylation, etc.), and even new biological activity can be generated. In this review, the recent advances in the phosphorylation of polysaccharides were reviewed from the perspectives of modification methods, structures, biological activities and structure-activity relationships.

Platycodon grandiflorus polysaccharides inhibit Pseudorabies virus replication via downregulating virus-induced autophagy

Pseudorabies virus (PRV) is one of the common pathogens in farms. Platycodon grandiflorus polysaccharide (PGPS) has been reported with a variety of biological activities. Autophagy is one of the vital mechanisms for cells to cope with virus infection, and it may also inhibit or promote virus replication. This study was conducted to investigate the antiviral activity of total PGPS(PGPS_t) against PRV and the role of virus-induced autophagy in the anti-PRV effect of PGPS_t in PK-15 cells. First, we established an infection model and detected the autophagy induced by PRV in PK-15 cells. Then, the protective effect of PGPS_t against PRV was evaluated, and the effect of PGPS_t on PRV replication and virus-induced autophagy were analysed by quantitative polymerase chain reaction, enzyme-linked immunosorbent assay, Western blot and confocal immunofluorescence. Results showed that PGPS_t can reduce the PRV replication. PRV infection resulted in the accumulation of autophagosomes, which were inhibited by PGPS_t. Moreover, PGPS_t upregulated the Akt/mammalian target of rapamycin (mTOR) signalling pathway repressed by PRV infection, whereas rapamycin attenuated the anti-PRV effect of PGPS_t. These findings suggest that PGPS_t possess a protective effect against PRV infection and can inhibit PRV replication through relieving PRV-induced autophagy. This article can provide ideas for the development of antiviral drugs.

Phosphorylation of polysaccharides: A review on the synthesis and bioactivities

Polysaccharides are macromolecules obtained from a wide range of sources and are known to have diverse biological activities. The biological activities of polysaccharides depend on their structure and physicochemical properties, including water solubility, monosaccharide composition, degree of branching, molecular structure, and molecular weight. Phosphorylation is a commonly used chemical modification method that improves the physicochemical properties of native polysaccharides, thus enhancing their biological activity, or even imparting novel biological activity. Therefore, phosphorylated polysaccharides have attracted increasing attention owing to their antioxidant, antitumor, antiviral, immunomodulatory, and hepatoprotective effects. In this review, we have discussed recent advances in the phosphorylation of polysaccharides, and the methods used for phosphorylation, structural characterization, and determination of biological activities, to provide a theoretical basis for the use of polysaccharides. The structure-activity relationship of phosphorylated polysaccharides and their use in the food and pharmaceutical industries needs to be further studied.

Extraction, purification, structural characteristics and biological properties of the polysaccharides from Codonopsis pilosula: A review

Codonopsis pilosula (Franch.) Nannf., as a well-known homology plant of medicine and food, has the function of replenishing the Qi, strengthening the spleen and tonifying the lung, nourishing the blood and engendering the liquid in traditional Chinese medicine. Accumulating evidence has demonstrated that the C. pilosula polysaccharides (CPPs) are one of the major and representative pharmacologically active macromolecules and present multiple biological activities both in vitro and in vivo methods, such as immunomodulatory, antitumor, antioxidant, neuroprotective, antiviral, anti-inflammatory, anti-fatigue, hypoglycemic, anti-hypoxia, renoprotective, gastroprotective, hepatoprotective, and prebiotic. The purpose of the present review is to provide comprehensively and systematically reorganized information in the extraction and purification, structure characterization, biological activities and the underlying mechanisms of action as well as toxicities of CPPs to support their therapeutic potentials and sanitarian functions. New valuable insights for the future researches regarding CPPs were also proposed in the fields of therapeutic agents and functional foods.

Immunomodulatory effect of Acanthopanax senticosus polysaccharide on immunosuppressed chickens

The immunomodulatory effect of Acanthopanax senticosus polysaccharide (ASPS) on immunosuppressed chickens induced by cyclophosphamide (Cy) was observed in this study. Four hundred 7-day-old chickens were randomly divided into 4 groups: vaccinated control group (VC group), Cy-challenged control group (Cy group), Cy-challenged + low-dose ASPS group (ASPS_L + Cy group), and Cy-challenged + high-dose ASPS group (ASPS_H + Cy group). All groups except the VC group were injected with Cy at a dose of 80 mg/kg/day of BW for 3 successive days to induce immunosuppression. At the age of 10 d, the ASPS_L + Cy group and ASPS_H + Cy group were intramuscularly injected with 0.2 mL of ASPS at the dose of 100 and 200 mg/mL/day, respectively, once a day for 3 successive days. The Cy group was injected with saline solution in the same way as the 2 ASPS groups. At the age of 14 d, the chickens were vaccinated with Newcastle disease (ND) vaccine in all groups. On day 7, 14, 21, and 28 after the vaccination, BW, lymphocyte proliferation, the serum antibody titers of the ND vaccine, the proportion of CD4⁺ and CD8⁺ T lymphocytes, and the concentrations of interferon gamma and IL-2 were determined. The results showed that chickens were injected with Cy at a dose of 80 mg/kg of BW for 3 d displayed lower immune responses than the control group, indicating that the immunosuppressive model was successfully established. At most time points, both high and low doses of ASPS could significantly promote lymphocyte proliferation; enhance BW, antibody titers, and the proportion of CD4⁺ and CD8⁺ T lymphocytes; and raised the concentrations of interferon gamma and IL-2 in Cy-treated chickens compared with those in the Cy control group (P < 0.05). These results indicated that ASPS could resist immunosuppression induced by Cy and may be a new-type immune adjuvant to improve vaccination in normal and immunosuppressed chickens.