The Preparation Of Phosvitin Phosphopeptides And Its Immune Functions In Mice

Effects of phosvitin phosphopeptides(PPP) from enzymic hydrolysates of phosvitin (PV) which come from chicken egg-yolk on immune functions of mice were investigated. On the basis of preparing PPP,the study focuses on the immune functions of mice in vivo or vitro.The whole study consisted of three experiments.Experiment 1:Preparing he PPPFirst,the phosvitin extracted from chicken egg-yolk was hydrolyzed by trypsin.Then, the hydrolysate was ultrafiltrated by ultrafiltration membrane.The filtrate of MW between 1kDa-3kDa was collected and lyophilized to get the PPP.PPP purity was determined by SDS-PAGE and N/P(molar ratio).The result indicated that electrophoresis strip of extracted PV was similar to the pure of PV.Electrophoresis of PPP showed that its MW was between 1-3kDa,N/P was 5.02.It was concluded that,the purity of PV and PPP prepared here was high enough for further study.Experiment 2:Effects of PPP on Immune Functions of Mice in vitroThe Mice's spleen lymphocytes and peritoneal macrophages were isolated and cultured to evaluate the effects of PPP on cell stimulation index(SI),phagocytosis index(PI) and cytokine secretions and immunoglobulin formation.Results showed that LPS or ConA administration significantly stimulated cell proliferation,phagocytosis,cytokine secretion and immunoglobulin formation in vitro(p＜0.05).PV administration(0.02 mg/mL) did not significantly affect the cell functions.However,PPP administration(0.02 mg/mL and 0.1 mg/mL) significantly stimulated the SI and elevated the concentrations of IgA,IL-2 and IL-6(p＜0.05) in culture supematant.The stimulating effects of PPP for LPS/ConA-induced cells were stronger than uninduced cells.These results suggested that PPP administration enhanced the SI,PI,cytokine secretions and immunoglobulin formation.When the LPS or ConA existed,the indicators were more obvious effects.Experiment 3:Effects of PPP on Immune Function of Mice in vivoTo determine the effects of orally administrated PPP on immune functions of mice.A total of 48 mice were randomly assigned to three treatments with 4 replications.Mice were administrated with 0.2 mL saline(control group),PPP and PV solutions(0.03 mg/g.BW.d), respectively.After 14 days,all mice were killed and sampled to investigate the growth performance and immune parameters.Results showed that the weight gain of PPP group was significantly improved(p＜0.05).The concentrations of serum total protein,albumin, globulin and glucose in PPP group tended to be increased than control or PV groups (p＞0.05),However,the concentrations of serum urea nitrogen,total cholesterol and triglyceride tended to be decreased.The spleen index and thymus index of PPP group were significantly improved(p＜0.05).Results form primary culture of spleen lymphocytes and peritoneal macrophages indicated that LPS and ConA significantly stimulated the SI and PI, and increased the concentrations of IgA,IL-1β,IL-2 and IL-6 in culture supematant (p＜0.05).The SI and PI were also significantly improved by PPP administration(p＜0.05). In addition,the concentrations of IgA,IL-2 and IL-6 in serum and spleen lymphocytes culture,the IL-1βin peritoneal macrophages culture were both actutely elevated(p＜0.05). However,none of these parameters altered by PV administration(p＞0.05).These results suggested that orally PPP administration not only improved the performance,but enhanced the SI,PI,cytokine secretions and immunoglobulin formation.When the LPS or ConA existed,the indicators were more obvious effects.In summary,PPP prepared from the PV not only improved the performance,but enhanced the whole body immune functions in mice.