Lycium barbarum polysaccharide inhibits the infectivity of Newcastle disease virus to chicken embryo fibroblast

Inhibition of multiple SARS-CoV-2 variants entry by Lycium barbarum L. polysaccharides through disruption of spike protein-ACE2 interaction

Viral respiratory infections are major human health concerns. The most striking epidemic disease, COVID-19 is still on going with the emergence of fast mutations and drug resistance of pathogens. A few polysaccharide macromolecules from traditional Chinese medicine (TCM) have been found to have direct anti-SARS-CoV-2 activity but the mechanism remains unclear. In this study, we evaluated the entry inhibition effect of Lycium barbarum polysaccharides (LBP) in vitro and in vivo. We found LBP effectively suppressed multiple SARS-CoV-2 variants entry and protected K18-hACE2 mice from invasion with Omicron pseudovirus (PsV). Moreover, we found LBP interfered with early entry events during infection in time-of-addition (TOA) assay and SEM observation. Further surface plasmon resonance (SPR) study revealed the dual binding of LBP with Spike protein and ACE2, which resulted in the disruption of Spike-ACE2 interaction and subsequently triggered membrane fusion. Therefore, LBP may act as broad-spectrum inhibitors of virus entry and nasal mucosal protective agent against newly emerging respiratory viruses, especially SARS-CoV-2.

Immunomodulatory and antiviral effects of Lycium barbarum glycopeptide on influenza a virus infection

Influenza is caused by a respiratory virus and has a major global impact on human health. Influenza A viruses in particular are highly pathogenic to humans and have caused multiple pandemics. An important consequence of infection is viral pneumonia, and with serious complications of excessive inflammation and tissue damage. Therefore, simultaneously reducing direct damage caused by virus infection and relieving indirect damage caused by excessive inflammation would be an effective treatment strategy. Lycium barbarum glycopeptide (LbGp) is a mixture of five highly branched polysaccharide-protein conjuncts (LbGp1-5) isolated from Lycium barbarum fruit. LbGp has pro-immune activity that is 1-2 orders of magnitude stronger than that of other plant polysaccharides. However, there are few reports on the immunomodulatory and antiviral activities of LbGp. In this study, we evaluated the antiviral and immunomodulatory effects of LbGp in vivo and in vitro and investigated its therapeutic effect on H1N1-induced viral pneumonia and mechanisms of action. In vitro, cytokine secretion, NF-κB p65 nuclear translocation, and CD86 mRNA expression in LPS-stimulated RAW264.7 cells were constrained by LbGp treatment. In A549 cells, LbGp can inhibit H1N1 infection by blocking virus attachment and entry action. In vivo experiments confirmed that administration of LbGp can effectively increase the survival rate, body weight and decrease the lung index of mice infected with H1N1. Compared to the model group, pulmonary histopathologic symptoms in lung sections of mice treated with LbGp were obviously alleviated. Further investigation revealed that the mechanism of LbGp in the treatment of H1N1-induced viral pneumonia includes reducing the viral load in lung, regulating the phenotype of pulmonary macrophages, and inhibiting excessive inflammation. In conclusion, LbGp exhibits potential curative effects against H1N1-induced viral pneumonia in mice, and these effects are associated with its good immuno-regulatory and antiviral activities.

Distinct Role of Lycium barbarum L. Polysaccharides in Oxidative Stress-Related Ocular Diseases

Oxidative stress is an imbalance between the increased production of reactive species and reduced antioxidant activity, which can cause a variety of disturbances including ocular diseases. Lycium barbarum polysaccharides (LBPs) are complex polysaccharides isolated from the fruit of L. barbarum, showing distinct roles in antioxidants. Moreover, it is relatively safe and non-toxic. In recent years, the antioxidant activities of LBPs have attracted remarkable attention. In order to illustrate its significance and underlying therapeutic value for vision, we comprehensively review the recent progress on the antioxidant mechanisms of LBP and its potential applications in ocular diseases, including diabetic retinopathy, hypertensive neuroretinopathy, age-related macular degeneration, retinitis pigmentosa, retinal ischemia/reperfusion injury, glaucoma, dry eye syndrome, and diabetic cataract.

Effects of Lycium barbarum Polysaccharides on Immunity and Metabolic Syndrome Associated with the Modulation of Gut Microbiota: A Review

Lycium barbarum polysaccharides (LBPs) have attracted increasing attention due to their multiple pharmacological activities and physiological functions. Recently, both in vitro and in vivo studies have demonstrated that the biological effects of dietary LBPs are related to the regulation of gut microbiota. Supplementation with LBPs could modulate the composition of microbial communities, and simultaneously influence the levels of active metabolites, thus exerting their beneficial effects on host health. Interestingly, LBPs with diverse chemical structures may enrich or reduce certain specific intestinal microbes. The present review summarizes the extraction, purification, and structural types of LBPs and the regulation effects of LBPs on the gut microbiome and their derived metabolites. Furthermore, the health promoting effects of LBPs on host bidirectional immunity (e.g., immune enhancement and immune inflammation suppression) and metabolic syndrome (e.g., obesity, type 2 diabetes, and nonalcoholic fatty liver disease) by targeting gut microbiota are also discussed based on their structural types. The contents presented in this review might help to better understand the health benefits of LBPs targeting gut microbiota and provide a scientific basis to further clarify the structure-function relationship of LBPs.

Germplasm Resources and Strategy for Genetic Breeding of Lycium Species: A Review

Lycium species (goji), belonging to Solanaceae, are widely spread in the arid to semiarid environments of Eurasia, Africa, North and South America, among which most species have affinal drug and diet functions, resulting in their potential to be a superior healthy food. However, compared with other crop species, scientific research on breeding Lycium species lags behind. This review systematically introduces the present germplasm resources, cytological examination and molecular-assisted breeding progress in Lycium species. Introduction of the distribution of Lycium species around the world could facilitate germplasm collection for breeding. Karyotypes of different species could provide a feasibility analysis of fertility between species. The introduction of mapping technology has discussed strategies for quantitative trait locus (QTL) mapping in Lycium species according to different kinds of traits. Moreover, to extend the number of traits and standardize the protocols of trait detection, we also provide 1,145 potential traits (275 agronomic and 870 metabolic) in different organs based on different reference studies on Lycium, tomato and other Solanaceae species. Finally, perspectives on goji breeding research are discussed and concluded. This review will provide breeders with new insights into breeding Lycium species.

Phytochemicals from Plant Foods as Potential Source of Antiviral Agents: An Overview

To date, the leading causes of mortality and morbidity worldwide include viral infections, such as Ebola, influenza virus, acquired immunodeficiency syndrome (AIDS), severe acute respiratory syndrome (SARS) and recently COVID-19 disease, caused by the SARS-CoV-2 virus. Currently, we can count on a narrow range of antiviral drugs, especially older generation ones like ribavirin and interferon which are effective against viruses in vitro but can often be ineffective in patients. In addition to these, we have antiviral agents for the treatment of herpes virus, influenza virus, HIV and hepatitis virus. Recently, drugs used in the past especially against ebolavirus, such as remdesivir and favipiravir, have been considered for the treatment of COVID-19 disease. However, even if these drugs represent important tools against viral diseases, they are certainly not sufficient to defend us from the multitude of viruses present in the environment. This represents a huge problem, especially considering the unprecedented global threat due to the advancement of COVID-19, which represents a potential risk to the health and life of millions of people. The demand, therefore, for new and effective antiviral drugs is very high. This review focuses on three fundamental points: (1) presents the main threats to human health, reviewing the most widespread viral diseases in the world, thus describing the scenario caused by the disease in question each time and evaluating the specific therapeutic remedies currently available. (2) It comprehensively describes main phytochemical classes, in particular from plant foods, with proven antiviral activities, the viruses potentially treated with the described phytochemicals. (3) Consideration of the various applications of drug delivery systems in order to improve the bioavailability of these compounds or extracts. A PRISMA flow diagram was used for the inclusion of the works. Taking into consideration the recent dramatic events caused by COVID-19 pandemic, the cry of alarm that denounces critical need for new antiviral drugs is extremely strong. For these reasons, a continuous systematic exploration of plant foods and their phytochemicals is necessary for the development of new antiviral agents capable of saving lives and improving their well-being.

The enhanced immunological activity of Paulownia tomentosa flower polysaccharide on Newcastle disease vaccine in chicken

The extracts of Paulownia tomentosa (P. tomentosa) exhibit multiple pharmacological activities. In the present study, P. tomentosa flower polysaccharides (PTFP) were extracted by water decoction and ethanol precipitation, and the immunologic modulations of PTFP against Newcastle disease (ND) vaccine was investigated in chickens. The results showed that in a certain range of concentrations, PTFP treatment can dose-dependently enhance lymphocyte proliferation. Then, 280 14-days-old chickens were randomly divided into seven groups, and vaccinated with ND vaccine except blank control (BC) group. At the first vaccination, chickens were orally administrated with PTFP at concentration ranging from 0 to 50 mg/kg once a day for 3 successive days, and the BC group was treated with physiological saline. The lymphocyte proliferation rate, serum antibody titer, and levels of interferon-γ (IFN-γ) were respectively measured on 7, 14, 21, and 28 days after the first vaccination. The results showed that PTFP at the suitable doses could significantly promote lymphocyte proliferation, enhance serum antibody titer, and improve serum IFN-γ concentrations. Taken together, these data indicated that PTFP could improve the immune efficacy against ND vaccine in chickens, and could be as the candidate of a new-type immune adjuvant.

Phyto-metabolites; An Impregnable Shield against Plant Viruses

Worldwide, economically important crops are under continuous threat from plant viruses as they reproduce within the host and spread via various biological and non biological means. The problem can be minimized via application of integrated management approaches involving utilization of resistant genotypes and reducing the insect vector population. But such strategies are rarely applied in developing countries and farmers prefer to use chemicals against all type of diseases. But increasing use of pesticides is a leading cause of disaster to our ecosystem so alternative means such as phyto-metabolites should be explored for eco friendly management of plant viruses. So here we have reviewed about different phyto-metabolites that can be effectively and potentially used against various plant virus diseases. We further explained about the various primary and secondary metabolites such as alkaloids, essential oils, flavonoids, polysaccharides and proteins. The review highlights the recent advances in the field of phyto-metabolites utilization against plant viruses and sums up via hoping through prospects that future drugs will be safer for human beings and our ecosystem.

Advances and prospects in biogenic substances against plant virus: A review

Plant virus diseases, known as 'plant cancer', are the second largest plant diseases after plant fungal diseases, which have caused great damage to agricultural industry. Since now, the most direct and effective method for controlling viruses is chemotherapeutics, except for screening of anti-disease species. As the occurrence and harm of plant diseases intensify, production and consumption of pesticides have increased year by year, and greatly contributed to the fertility of agriculture, but also brought a series of problems, such as the increase of drug resistance of plant pathogens and the excessive pesticide residues. In recent years, biopesticide, as characterized by environmentally safe due to low residual, safe to non-target organism due to better specificity and not as susceptible to produce drug resistance due to diverse work ways, has gained more attention than ever before and exhibited great development potential. Now much progress has been made about researches on new biogenic anti-plant-virus substances. The types of active components include proteins, polysaccharides and small molecules (alkaloids, flavonoids, phenols, essential oils) from plants, proteins and polysaccharides from microorganisms, polysaccharides from algae and oligochitosan from animals. This study summarized the research advance of biogenic anti-plant-virus substances in recent years and put forward their further development in the future.

Polysaccharides from Traditional Chinese Medicines: Extraction, Purification, Modification, and Biological Activity

Traditional Chinese Medicine (TCM) has been used to treat diseases in China for thousands of years. TCM compositions are complex, using as their various sources plants, animals, fungi, and minerals. Polysaccharides are one of the active and important ingredients of TCMs. Polysaccharides from TCMs exhibit a wide range of biological activities in terms of immunity- modifying, antiviral, anti-inflammatory, anti-oxidative, and anti-tumor properties. With their widespread biological activities, polysaccharides consistently attract scientist's interests, and the studies often concentrate on the extraction, purification, and biological activity of TCM polysaccharides. Currently, numerous studies have shown that the modification of polysaccharides can heighten or change the biological activities, which is a new angle of polysaccharide research. This review highlights the current knowledge of TCM polysaccharides, including their extraction, purification, modification, and biological activity, which will hopefully provide profound insights facilitating further research and development.

In Vitro Protective Effects of Lycium barbarum Berries Cultivated in Umbria (Italy) on Human Hepatocellular Carcinoma Cells

Lycium barbarum is a famous plant in the traditional Chinese medicine. The plant is known to have health-promoting bioactive components. The properties of Lycium barbarum berries cultivated in Umbria (Italy) and their effect on human hepatocellular carcinoma cells (HepG2) have been investigated in this work. The obtained results demonstrated that the Lycium barbarum berries from Umbria region display high antioxidant properties evaluated by total phenolic content and ORAC method, on hydrophilic and lipophilic fractions. Moreover, on HepG2 cell line Lycium barbarum berries extract did not change cell viability analyzed by MTT and Trypan blue exclusion assay and did not induce genotoxic effect analyzed by comet assay. Furthermore, it was demonstrated, for the first time, that the berries extract showed a protective effect on DNA damage, expressed as antigenotoxic activity in vitro. Finally, Lycium barbarum berries extract was able to modulate the expression of genes involved in oxidative stress, proliferation, apoptosis, and cancer. In particular, downexpression of genes involved in tumor migration and invasion (CCL5), in increased risk of metastasis and antiapoptotic signal (DUSP1), and in carcinogenesis (GPx-3 and PTGS1), together with overexpression of tumor suppressor gene (MT3), suggested that Umbrian Lycium barbarum berries could play a protective role against hepatocellular carcinoma.

Anti-NDV activity of baicalin from a traditional Chinese medicine in vitro

The purpose of this study was to investigate the anti-Newcastle disease virus (NDV) activities of baicalin from Scutellaria baicalensis, a Traditional Chinese Medicine in vitro. Chicken embryo fibroblasts (CEFs) were infected with NDV, and quantitative analysis of apoptotic cells was performed using flow cytometry. Cytotoxicity and anti-viral activities of baicalin were studied using the MTT method. The results showed that the maximal safe concentrations of baicalin to CEFs was 1 × 2(-2) mg/ml. Baicalin could directly kill NDV, inhibit the infectivity of NDV to CEF and block intracellular NDV. It inhibited the apoptosis of NDV-infected CEFs and suppressed the spread of NDV. These results indicate that baicalin has strong anti-NDV activity and has the potential for use as components of an antiviral drug.

Inhibitory effect of polysaccharide peptide (PSP) against Tobacco mosaic virus (TMV)

Polysaccharides are essential macromolecules present in all living organisms, and have many kinds of biological activities, such as anti-oxidation, hypoglycemic, enhancing immunity, anti-aging, anti-rheumatism, anti-cancer and so on. In this study, the antiviral activity of polysaccharide peptide (PSP) was tested, compared with Ningnanmycin, and firstly found it has a stronger antiviral activity by using half-leaf method and leaf disk method. Subsequently, the mechanism of antiviral activity of PSP was preliminarily studied. As a result, its antiviral effect was better than the commercial agent Ningnanmycin, despite of protective effect, curative effect and inactivation effect. On the other hand, PSP as a commercial anti-cancer drug could easily and rapidly get in large quantities by liquid fermentation, which makes the industrialized production feasible. Also PSP is less toxic, easily biodegradable and ecofriendly. All the results are suggesting that PSP has potential as a pesticide to be used for the control of plant virus in the future.

Solomonseal polysaccharide and sulfated Codonopsis pilosula polysaccharide synergistically resist Newcastle disease virus

Five combinations of three ratios (PS₉-sPS₁, PS₇-sPS₃ and PS₆-sPS₄) were prepared with polysaccharide (PS) and sulfated polysaccharide (sPS). The antiviral activities of these compounds were subsequently compared in vitro using the MTT assay, observation of the virus structure and immunofluorescence. The results demonstrated that SP₉-sCP₁, CP₇-sCA₃, EP₇-sAP₃, CA₉-sEP₁ and EP₇-sCA₃ presented higher activities, and SP₉-sCP₁ displayed the highest virus inhibition rate and clearly killed the virus and inhibited viral antigen expression. In an in vivo test, 28-day-old chickens were challenged with Newcastle disease virus (NDV) and were administered the five drug combinations. On day 14 after the challenge, the morbidity, mortality and cure rate in each group were calculated. The results indicated that SP₉-sCP₁ presented the lowest morbidity and mortality and the highest cure rate. These results indicate that Solomonseal polysaccharide and sulfated Codonopsis pilosula polysaccharide synergistically resist NDV. Moreover, SP₉-sCP₁ had the highest efficacy and may be used as a new antiviral drug.

Antiviral effect of sulfated Chuanmingshen violaceum polysaccharide in chickens infected with virulent Newcastle disease virus

Newcastle disease virus (NDV) belonging to the Paramyxovirinae subfamily is one of the most devastating pathogens in poultry. Although vaccines are widely applied to control the infection, outbreaks of Newcastle disease (ND) repeatedly happen. Currently, there are no alternative control measures available for ND. In the present study, we found that sulfated Chuanmingshen violaceum polysaccharide (sCVPS) were potent inhibitors of NDV in specific pathogen free chickens infected with a virulent strain. With sCVPS treatment, the survival rate increased by almost 20% and virus titers in test organs, including brain, lung, spleen and thymus, were significantly decreased. The sCVPS also exhibited the ability to prevent viral transmission by reducing the amount of virus shed in saliva and feces. Higher concentrations of interferon α and γ in serum were detected in chickens treated with sCVPS, indicating that one of the antiviral mechanisms may be attributed to the property of immunoenhancement. Histopathological examination showed that sCVPS could alleviate the tissue lesions caused by NDV infection. These results suggest that sCVPS are expected to be a new alternative control measure for NDV infection and further studies could be carried out to evaluate the antiviral activity of sCVPS against other paramyxoviruses.

An evidence-based update on the pharmacological activities and possible molecular targets of Lycium barbarum polysaccharides

Lycium barbarum berries, also named wolfberry, Fructus lycii, and Goji berries, have been used in the People’s Republic of China and other Asian countries for more than 2,000 years as a traditional medicinal herb and food supplement. L. barbarum polysaccharides (LBPs) are the primary active components of L. barbarum berries and have been reported to possess a wide array of pharmacological activities. Herein, we update our knowledge on the main pharmacological activities and possible molecular targets of LBPs. Several clinical studies in healthy subjects show that consumption of wolfberry juice improves general wellbeing and immune functions. LBPs are reported to have antioxidative and antiaging properties in different models. LBPs show antitumor activities against various types of cancer cells and inhibit tumor growth in nude mice through induction of apoptosis and cell cycle arrest. LBPs may potentiate the efficacy of lymphokine activated killer/interleukin-2 combination therapy in cancer patients. LBPs exhibit significant hypoglycemic effects and insulin-sensitizing activity by increasing glucose metabolism and insulin secretion and promoting pancreatic β-cell proliferation. They protect retinal ganglion cells in experimental models of glaucoma. LBPs protect the liver from injuries due to exposure to toxic chemicals or other insults. They also show potent immunoenhancing activities in vitro and in vivo. Furthermore, LBPs protect against neuronal injury and loss induced by β-amyloid peptide, glutamate excitotoxicity, ischemic/reperfusion, and other neurotoxic insults. LBPs ameliorate the symptoms of mice with Alzheimer’s disease and enhance neurogenesis in the hippocampus and subventricular zone, improving learning and memory abilities. They reduce irradiation- or chemotherapy-induced organ toxicities. LBPs are beneficial to male reproduction by increasing the quality, quantity, and motility of sperm, improving sexual performance, and protecting the testis against toxic insults. Moreover, LBPs exhibit hypolipidemic, cardioprotective, antiviral, and antiinflammatory activities. There is increasing evidence from preclinical and clinical studies supporting the therapeutic and health-promoting effects of LBPs, but further mechanistic and clinical studies are warranted to establish the dose–response relationships and safety profiles of LBPs.

Polyphenolic content, antioxidant and antimicrobial activities of Lycium barbarum L. and Lycium chinense Mill. leaves

This study was performed to evaluate the in vitro antioxidant and antimicrobial activities and the polyphenolic content of Lycium barbarum L. and L. chinense Mill. leaves. The different leave extracts contain important amounts of flavonoids (43.73 ± 1.43 and 61.65 ± 0.95 mg/g, respectively) and showed relevant antioxidant activity, as witnessed by the quoted methods. Qualitative and quantitative analyses of target phenolic compounds were achieved using a HPLC-UV-MS method. Rutin was the dominant flavonoid in both analysed species, the highest amount being registered for L. chinense. An important amount of chlorogenic acid was determined in L. chinense and L. barbarum extracts, being more than twice as high in L. chinense than in L. barbarum. Gentisic and caffeic acids were identified only in L. barbarum, whereas kaempferol was only detected in L. chinense. The antioxidant activity was evaluated by DPPH, TEAC, hemoglobin ascorbate peroxidase activity inhibition (HAPX) and inhibition of lipid peroxidation catalyzed by cytochrome c assays revealing a better antioxidant activity for the L. chinense extract. Results obtained in the antimicrobial tests revealed that L. chinense extract was more active than L. barbarum against both Gram-positive and Gram-negative bacterial strains. The results suggest that these species are valuable sources of flavonoids with relevant antioxidant and antimicrobial activities.

Scutellaria polysaccharide inhibits the infectivity of Newcastle disease virus to chicken embryo fibroblast

BACKGROUND

To select the antiviral active site of Scutellaria polysaccharide (SPS), safe concentrations of crude total Scutellaria polysaccharide (SPS(t)) and fractional polysaccharide SPS₅₀, SPS₆₀, SPS₇₀ and SPS₈₀ on chicken embryo fibroblast (CEF) were first compared using the MTT method. Then, SPS(t), SPS₅₀, SPS₆₀, SPS₇₀, and SPS₈₀ at five concentrations within the safe concentration, together with Newcastle disease virus (NDV), were added to the cultivating system of CEF in three models: pre-addition of polysaccharide, post-addition of polysaccharide, and simultaneous addition of polysaccharides and NDV after mixing. The effects of SPS on the cellular infectivity of NDV (A₅₇₀ value and the highest viral inhibitory rate) were compared using the MTT method.

RESULTS

At appropriate concentrations, the five polysaccharides could significantly inhibit the infectivity of NDV on CEF. Among the five polysaccharide groups, the SPS₈₀ group exhibited the highest viral inhibitory rate in the three sample-addition modes.

CONCLUSION

This finding indicates that SPS₈₀ possesses the best efficacy as a component of antiviral polysaccharide drug.

Comparison of Bush Sophora Root polysaccharide and its sulfate's anti-duck hepatitis A virus activity and mechanism

In order to research the sulfating modification in enhancing the anti-duck hepatitis A virus (DHAV) activity of Bush Sophora Root polysaccharide (BSRPS), sulfated Bush Sophora Root polysaccharide (sBSRPS) was prepared by chlorosulfonic acid-pyridine method. KBr pellets method was applied to analyze their different structures. Anti-DHAV activity was studied by duck embryonic hepatocytes culture in vitro and artificial inoculation method in vivo. Direct immunofluorescence method and Real-time PCR were applied to study the antiviral mechanism of adsorption, replication and release in vitro and the dynamic change of virus content of blood in vivo. The results showed at the most effective content, sBSRPS (7.813 μg/mL) could inhibit both replication and release of DHAV in vitro, BSRPS (500 μg/mL) only inhibit replication. The relative expression of DHAV gene at the 8thh and the mortality rate of sBSRPS group were significantly reduced. These results indicated sBSRPS performed more effectively in anti-DHAV activity than BSRPS.

Antiviral activity of sulfated Chuanmingshen violaceum polysaccharide against Newcastle disease virus

Newcastle disease virus (NDV) is a member of Paramyxovirinae subfamily and can infect most species of birds causing severe economic losses. The current control measure is vaccination, but infections cannot be completely prevented. It remains a constant threat to the poultry industry and new control measures are urgently needed. This study demonstrates that sulfated Chuanmingshen violaceum polysaccharides (sCVPSs) were potent inhibitors of NDV, with 50 % inhibitory concentrations (IC50) ranging from 62.55 to 76.31 µg ml(-1) in Baby hamster kidney fibroblasts clone 21 (BHK-21) and from 101.57 to 125.90 µg ml(-1) in chicken embryo fibroblasts (CEF). sCVPS is more effective than heparan sulfate (HS; as a positive control) with IC50 values of 99.28 µg ml(-1) in BHK-21 and 118.79 µg ml(-1) in CEF. sCVPSs and HS exhibit anti-NDV activity by prevention of the early stages of viral life. The mechanism of action study indicated that virus adsorption in BHK-21, and both virus adsorption and penetration in CEF were inhibited by sCVPSs. When the number of viruses was increased to an m.o.i. of 0.1 in the immunofluorescence study and to an m.o.i. of 1 in the fluorescent quantitative PCR study, viral infection was also significantly suppressed; the antiviral activity of sCVPSs was independent of the m.o.i. sCVPSs also prevented the cell-to-cell spread of NDV. In vivo tests carried out on specific pathogen-free (SPF) chickens showed that sCVPSs also inhibited virus multiplication in heart, liver, spleen, lung and kidney. These results indicated that sCVPSs perform more effectively than HS as antiviral agents against NDV, and can be further examined for their potential as an alternative control measure for NDV infection.

Astragalus polysaccharide enhances immunity and inhibits H9N2 avian influenza virus in vitro and in vivo

This study investigated the humoral immunization of Astragalus polysaccharide (APS) against H9N2 avian influenza virus (H9N2 AIV) infection in chickens.The effects of APS treatment on H9N2 infection was evaluated by an MTT [3(4, 5-dimethylthiazol-2-yl)-2, 3-diphenyl tetrazolium bromide] assay and analysis of MHC and cytokine mRNA expression. The effect on lymphocyte and serum antibody titers in vivo was also investigated. IL-4, IL-6, IL-10, LITAF, IL-12 and antibody titers to H9N2 AIV were enhanced in the first week after APS treatment. The results indicated that APS treatment reduces H9N2 AIV replication and promotes early humoral immune responses in young chickens.

Vascular endothelial growth factors signalling in normal human dental pulp: a study of gene and protein expression

In the well-vascularized dental pulp vascular endothelial growth factor A (VEGF-A) is expressed. Vascular endothelial growth factor A is a member of the VEGF family, which includes VEGFs-B, -C, and -D. The latter three have not been investigated in the pulp. Vascular endothelial growth factors C and D are the only ligands for vascular endothelial growth factor receptor (VEGFR)-3, which is usually expressed in lymphatic endothelium. They can also activate VEGFR-2, the main angiogenic receptor. We aimed to study VEGFs signalling in human dental pulp at the gene level and to identify the cellular source for protein expression using immunolabelling. All VEGFs (-A, -B, -C, and -D) were expressed in the pulp and may exert both autocrine and paracrine effects in blood vessels and immune cells found to be equipped with VEGFRs-2 and -3. Lymphatic vessel endothelial hyaluronan receptor-positive macrophages, known to be involved in angiogenesis, were found in the pulp, whereas lymphatic vessels were not detected. Twenty-six of 84 VEGF signalling genes, including VEGFR-3, were expressed at a significantly higher level in the pulp than in the control periodontal ligament. In conclusion, the normal human pulp represents a tissue with relatively high VEGF signalling involving both immune responses and vascular activity.

Antiviral Properties of Phytochemicals

In recent years, significant progress has been achieved for the development of novel anti-viral drugs. These newly developed drugs belong to three groups of compounds, nucleoside analogues, thymidine kinase-dependent nucleotide analogues and specific viral enzyme inhibitors. It has been found that the natural products, like plant-derived compounds (phytochemicals) as well as traditional medicines, like traditional Chinese medicines (TCM), Ayurvedic medicines and so on, are the important sources for potential and novel anti-viral drugs. In this chapter, the history of natural products as antiviral drugs, the approaches to discover potential lead compounds, and the anti-viral properties of phytochemicals with different action mechanisms are discussed. The key conclusion is that natural products are most important sources for novel anti-viral drugs.

The effect of Lycium barbarum polysaccharide on alcohol-induced oxidative stress in rats

The aim of this study was to investigate the effects of Lycium barbarum Polysaccharide (LBP) on alcohol-induced liver damage in rats. A total of 36 rats were divided into control, ethanol and ethanol + LBP groups. Rats in the ethanol group were fed 7 g ethanol/kg body weight by gastric infusion, three times a day, for 30 consecutive days, while rats in the control group received the same volume of physiological saline instead of ethanol, and rats in ethanol + LBP group were fed both ethanol (7 g/kg body weight) and LBP (300 mg/Kg body weight/day). Alcoholic liver injury was examined by serum ALT and AST activities, alcoholic fatty liver was assessed by lipid levels, and oxidative stress was evaluated by SOD, CAT, GSH-Px, GSH and MDA assays. In the ethanol group, a significant elevation of enzymes and lipid in serum, increased MDA level and depletion of SOD, CAT, GSH-Px and GSH in liver were observed. LBP administration significantly ameliorated liver injury, prevented the progression of alcohol-induced fatty liver, and improved the antioxidant functions when compared with the ethanol group. Histopathological examination of rat liver revealed that LBP administration protected liver cells from the damage induced by ethanol. The results suggest that LBP is a promising agent to protect the liver from hepatotoxicity and fatty liver induced by ethanol intake.

Chemical characterization of Lycium barbarum polysaccharides and its inhibition against liver oxidative injury of high-fat mice

In this study, we investigated chemical structure of Lycium barbarum polysaccharides and its modulatory effect on oxidative stress in high-fat mice. The polysaccharides mainly contained xylose and glucose. Little amount of rhamnose, mannose and galactose was observed. The Lycium barbarum polysaccharides had IR bands at 800-1200 cm(-1), 1450-1800 cm(-1), 2500-3000 cm(-1), and 3200-3600 cm(-1), which were distinctive absorptions of polysaccharides. Rats are fed with high-fat diet for 2 months. Results showed that blood and liver antioxidant enzymes activities and GSH level in model mice significantly decreased, and MDA level significantly increased (P<0.01) compared to normal control mice. Administration of Lycium barbarum polysaccharides significantly increased antioxidant enzymes activities and decreased MDA level in mice (P<0.01) compared to model group.

Sulfated modification can enhance the immune-enhancing activity of lycium barbarum polysaccharides

In test in vitro, four sulfated lycium barbarum polysaccharides (sLBPSs) with different degrees of sulfation (DS), sLBPS0.7, sLBPS1.1, sLBPS1.5 and sLBPS1.9, were added into cultured chicken peripheral lymphocytes and the changes of lymphocytes proliferation were compared by MTT assay taking the non-modified LBPS as control. Two sLBPSs with better efficacy, sLBPS1.5 and sLBPS1.9 were selected. In test in vivo, one hundred 14-day-old chickens were averagely divided into five groups randomly. The chickens except blank control group were vaccinated with Newcastle disease vaccine, repeated vaccination at 28 days old. At the same time of the first vaccination, the chickens in three experimental groups were injected with 0.5 mL of sLBPS1.5, sLBPS1.9 and LBPS at 4 mg mL(-1), in vaccination control group, with 0.5 mL of physiological saline, once a day for three successive days. On days 7, 14, 21 and 28 after the first vaccination, the changes of peripheral lymphocytes proliferation and serum HI antibody titer were determined. The result showed that two sLBPSs could significantly promote lymphocytes proliferation and enhance serum antibody titer. These results indicated that sulfated modification could enhance the immune-enhancing activity of LBPS, which there was a certain relativity with the DS of sulfated polysaccharide. sLBPS1.5 possessed the best efficacy and would be expected as the component drug of a new-type immunopotentiator.