Immunoregulatory Effects of Ethyl-acetate Fraction of Extracts from Tetrastigma Hemsleyanum Diels et. Gilg on Immune Functions of ICR Mice

Objective To evaluate the effects of ethyl-acetate fraction （EAF） of extracts from Tetrastigma hemsleyanum Diels et. Gilg （TDG） on immune functions of ICR mice. Methods ICR mice were exposed to different doses of EAF for 15 or 30 days and then their immune functions were analyzed, including ConA-induced splenic lymphocyte transformation, SRBC- induced delayed type hypersensitivity response, serum hemolysin analysis, antibody-producing cells, peritoneal macrophage phagocytized chicken red blood cells, natural killer cell activity, and serum level of cytoldnes. Results EAF of extracts from TDG at different doses had various effects on immune functions of ICR mice. As compared with the controls, it increased the mouse spleen lymphocyte transformation induced by ConA, the left-hind voix pedis thickness and the number of plague forming cells （PFCs） at the dose of 1.82 mg/mL, 5.48 mg/mL, and 9.12 mg/mL, respectively; increased the ink clearance ability at the dose of 0.91 mg/mL, 1.82 mg/mL, 5.48 mg/mL, and 9.12 mg/mL, respectively; increased the phagocytosis index of mononuclear-macrophages and production of serum interferon-gamma （IFN-？） at the dose of 5.48 mg/mL; and could promote the production of serum tumor necrosis factor-alpha （TNF-α） at the dose of 9.12 mg/mL. Conclusion EAF of extracts from TDG can regulate mouse immune functions in vivo.

Bioactivity of silk fibroin peptides on vascular endothelial cells

To determine the contribution of non-repetitive domains to the bioactivity of the heavy chain in silk fibroin(SF)macromolecules,a gene motif f(1)encoding this fragment and its multimers(f(4)and f(8))were biosynthesized from Escherichia coli BL21.Based on the positive application potential of SF materials for the vascular tissue engineering,this study focused on examining the active response of these polypeptides to vascular endothelial cells.Biosynthetic polypeptides F(1),F(4),and F(8)were separately grafted onto the surfaces of bioinert polyethylene terephthalate(PET)films,resulting in remarkable improvements in the spread and proliferation of human umbilical vein endothelial cells(HUVECs).Using the same grafting dose,the activity of cells on polypeptide-modified PET films enhanced with the increase of the molecular weight of those grafted polypeptides from F(1)to F(8).Meanwhile,the growth of cells on the surface of the alkaline-treated PET film was improved,indicating that the hydrophilicity of the surface material had influence on the growth of HUVECs.Moreover,on surfaces with the same water contact angle,the spread and proliferation activity of cells on PET films were significantly lower than those on polypeptide-modified PET films.