Yuanliang Hu

Sulfated modification can enhance the adjuvanticity of lentinan and improve the immune effect of ND vaccine.

The purpose of this research is to study the effect of sulfated lentinan (sLNT) on immune effect of Newcastle disease (ND) vaccine. In immune response test, 14-day-old chickens were vaccinated with ND vaccine then grouped respectively to inject three sLNTs at two doses, once a day for three successive days, taking non-sulfated lentinan (LNT) as the control. The changes of serum antibody titer and peripheral lymphocyte proliferation were determined before and after vaccination. In immune protection test, 35-day-old chickens were challenged with ND virus (NDV) after treated similar to above mentioned. The morbidity and mortality of chickens were observed, and the changes of serum antibody titer and peripheral lymphocyte proliferation were measured before and after challenge. The results showed that three modified sLNTs could significantly enhance serum antibody titer and promote lymphocyte proliferation in two experimental chickens, and reduce morbidity and mortality of chickens challenged with NDV, which were better than that of non-modified LNT. Their high doses in enhancing antibody titer and low doses in promoting lymphocyte proliferation were more preferable. These results indicated that sulfated modification could enhance the adjuvanticity of LNT and improve the immune effect of ND vaccine. sLNT(2) possessed the best efficacy and would be expected as the candidate of a new-type immune adjuvant.

Immunoenhancement effect of rehmannia glutinosa polysaccharide on lymphocyte proliferation and dendritic cell.

The aim of this study is to investigate immunomodulatory effect of rehmannia glutinosa polysaccharide (RGP) on murine splenic lymphocyte and bone marrow derived dendritic cells (DCs). Splenic lymphocytes obtained from mice were co-cultured with RGP for 48 h and then harvested for analyzing with MTT method. The cytokine production of T lymphocytes was measured by ELISA. Effects of RGP treatment on DCs were investigated and assessed by MTT method. The results showed RGP significantly stimulated lymphocyte proliferation and the growth rate of T cell was more significant. The IL-2 and IFN-γ production of T lymphocyte were significantly upregulated after being stimulated with RGP. DCs stimulating on proliferation of T cells and the ability of antigen presenting of DCs have been enhanced under the stimulation of RGP. In conclusion, these findings provided valuable information that RGP possessed strong immunoenhancement activity, which provided the theoretical basis for the further experiment.

Optimization of selenylation conditions for Chinese angelica polysaccharide based on immune-enhancing activity

Chinese angelica polysaccharide (CAP) was extracted by water decoction and ethanol precipitation, purified through eliminating protein by Sevage method and column chromatography of Sephadex G-200, then selenizingly modified by nitric acid-sodium selenite method according to L(9)(3(4)) orthogonal design of three-factors, the usage amount of sodium selenite, reaction temperature and reaction time, at three level to obtain nine selenizing CAPs, sCAP(1)-sCAP(9). Their effects on chicken peripheral lymphocytes proliferation in vitro were compared by MTT assay taking the non-modified CAP as control. The results showed that selenylation modification could significantly enhance the immune-enhancing activity of CAP, sCAP(2) presented best effect and the optimal modification conditions were 200mg of sodium selenite for 500 mg of CAP, the reaction temperature of 70 °C and the reaction time of 6 h.

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.

Optimization of selenylation conditions for lycium barbarum polysaccharide based on antioxidant activity.

Lycium barbarum polysaccharide (LBP) was modified by HNO3-Na2SeO3 method according to L9(3(4)) orthogonal design to obtain nine selenizing LBPs (sLBPs), sLBP1-sLBP9. Their antioxidant activities in vitro were compared by free radical-scavenging test. sLBP6, sLBP8 and sLBP9 presented stronger activity. In vivo test, 14-day-old chickens were injected respectively with sLBP6, sLBP8 and sLBP9 taking LBP as control, and serum GSH-Px and SOD activities and MDA content were determined. The results showed that three sLBPs could significantly enhance GSH-Px and SOD activities and decrease MDA content. The actions of sLBPs were significantly stronger than that of unmodified LBP. These results indicated that selenylation modification could significantly enhance the antioxidant activities of LBP, sLBP6 possessed the best efficacy and could be exploited into an antioxidant. The optimal modification conditions were 400mg of sodium selenite for 500 mg of LBP, reaction temperature of 70 °C and reaction time of 6h.

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

Lycium barbarum polysaccharide (LBPS) was extracted by water decoction and ethanol precipitation. After purification, four sulfated lycium barbarum polysaccharides (sLBPSs), sLBPS(0.7), sLBPS(1.1), sLBPS(1.5) and sLBPS(1.9), were prepared by chlorosulfonic acid-pyridine method respectively at four designed modification conditions. Four sLBPSs at 5 concentrations, within the safety concentration scope, and Newcastle disease virus (NDV) were added into cultivating system of chick embryo fibroblast (CEF) respectively in three modes, pre- and post-adding polysaccharide and simultaneous adding polysaccharide and virus after being mixed. The effects of sLBPSs on cellular infectivity of NDV were assayed by MTT method taking the non-modified LBPS as control. The results showed that sLBPS(1.5), sLBPS(1.9) and sLBPS(1.1) in three sample-adding modes, sLBPS(0.7) in simultaneous adding after being mixed could significantly inhibit the infectivity of NDV to CEF. The viral inhibitory rate of sLBPS(1.5) in pre- and simultaneous adding and sLBPS(1.9) in post-adding was the highest. Non-modified LBPS did not present significant effect in any sample-adding mode. These results indicated that sulfated modification could significantly enhance the antiviral activity of LBPS, which was correlated with the degree of sulfation (DS) of sLBPS. sLBPS(1.5) and sLBPS(1.9) possessed better activity and would be as the compositions of antiviral prescription.

Compound Chinese herbal medicinal ingredients can enhance immune response and efficacy of RHD vaccine in rabbit.

In order to validate the immune-enhancement efficacy of compound Chinese herbal medicinal ingredients (cCHMIs), made with astragalus polysaccharide (APS), epimedium polysaccharide (EPS), propolis flavone (PF) and ginsenosides (GS), as immune potentiator or vaccine adjuvants for rabbits, the effects of two cCHMIs on rabbit lymphocyte proliferation and IFN-gamma and IL-10 mRNA expression of T lymphocyte in vitro were determined. At the same time, two cCHMIs were injected into 35-day-old rabbits after mixed with rabbit hemorrhagic disease (RHD) vaccine taking aluminum adjuvant and phosphate-buffered saline (PBS) as controls. On days 7, 14, 21, 35 and 49 after the vaccination, the dynamic changes of peripheral lymphocyte proliferation and serum antibody titers of the rabbits were analyzed. On day 63, all rabbits were challenged with RHD virus. The results showed that the two cCHMIs could significantly promote rabbit lymphocyte proliferation and IFN-gamma and IL-10 mRNA expression of T lymphocyte in vitro. In vivo, two cCHMIs could significantly enhance serum antibody titers and lymphocyte proliferation. Their adjuvanticity was slightly superior to aluminum adjuvant. All the rabbits vaccinated with the cCHMIs adjuvant vaccine were protected. These findings confirmed that two cCHMIs possessed better immune-enhancement efficacy and would be used as effective immune adjuvant of RHD vaccine.

Epimedium polysaccharide and propolis flavone can synergistically stimulate lymphocyte proliferation in vitro and enhance the immune responses to ND vaccine in chickens.

Four prescriptions, epimedium flavone plus propolis flavone (EF-PF), epimedium flavone plus propolis extracts (EF-PE), epimedium polysaccharide plus propolis flavone (EP-PF) and epimedium polysaccharide plus propolis extracts (EP-PE), were prepared and their immune-enhancing effects were compared. In test in vitro, the effects of them on chicken peripheral lymphocyte proliferation were determined by MTT method. The results showed that EP-PF group presented the highest stimulating index at most concentrations. In immune test, 300 14-day-old chickens were randomly divided into six groups and vaccinated with ND vaccine except for blank control (BC) group, re-challenged at 28 days of age. At the same time of the first vaccination, the chickens in four experimental groups were injected, respectively, with four prescriptions. The changes of the lymphocyte proliferation and antibody titer were determined. On day 28 after the first vaccination, the chickens except for BC group were challenged with NDV, the immune protective effect was observed. The results displayed that in EP-PF group, the antibody titers, lymphocyte proliferation and protective rate were the highest, the morbidity and mortality were the lowest. In dose test, 14-day-old chickens were randomly divided into five groups. The treatment and determinations were the same as the immune test except that the chickens in experimental groups were injected, respectively, with high, medium and low doses of EP-PF. The results revealed that in medium dose group, the antibody titers, lymphocyte proliferation and protective rate were the highest, the morbidity and mortality were the lowest. These results indicated that EP and PF possessed synergistically immune enhancement, EP-PF had the best efficacy, especially at medium dose, and would be expected to exploit into a new-type immunopotentiator.

In vitro antiviral activity of sulfated Auricularia auricula polysaccharides

Total Auricularia auricula polysaccharide (AAP(t)) was prepared by extracting and removing the proteins. Column chromatography was used to further graded it into AAP(1) and AAP(2). Three AAPs were modified by chlorosulfonic acid-pyridine method to obtain three sulfated AAPs (sAAPs), sAAP(t), sAAP(1) and sAAP(2), respectively. Three sAAPs and Newcastle disease virus (NDV) were added into cultivation system of chicken embryo fibroblast (CEF) in three manners, pre-, post- and simultaneous-adding polysaccharide with NDV respectively, taking three non-modified AAPs as control. Their anti-viral activities were compared by MTT method. The results showed that sAAPs and AAPs at a certain concentration could significantly inhibit the cellular infectivity of NDV in three manners. The effects of sAAPs were better than that of AAPs. It indicated that sulfated modification could enhance the antiviral activity of AAP. sAAP(1) and sAAP(t) possessed stronger activity and would be as the component of a new-type antiviral drug.

The immunological activity of propolis flavonoids liposome on the immune response against ND vaccine.

Three hundred and fifty 14-day-old chickens were randomly assigned to 7 groups. At the same time of vaccination with Newcastle disease vaccine, the chickens in experimental groups were injected with propolis flavonoids liposome (PFL) at three doses, PF and blank liposome, respectively. The titer of serum antibody, concentrations of immunoglobulins G (IgG) and immunoglobulins M (IgM), activity of lymphocytes proliferation and concentrations of cytokines were measured. The results showed that three doses of PFL could significantly enhance antibody titer, concentrations of IgG, IgM, and promote lymphocyte proliferation, interferon-γ and interleukin-2 secretion, and its high and medium doses possessed the best efficacy. In general evaluation, the efficacy of PFL was the best, with certain of dose- and time-effect relationships. These findings indicated that the immunological activity of PF could be enhanced with liposome encapsulation.