抄録
Cepharanthine (CEP) is reported to be effective in prevention of immune suppression and leukopenia induced by administration of antitumor agents. In this study, we examined relationship between the phagocytotic activity of peritoneal macrophages and the immuno-modulating action of CEP-incorporating liposomes composed of egg phosphatidylcholine and cholesterol in a molar ratio of 7 : 2. Multilamellar liposomes (MLV) were prepared by vortexing dried lipid films, and small unilamellar liposomes (SUV) by ultrasonication of MLV. Antigen (pneumococcal polysaccharides) and CEP-containing liposomes were injected intraperitoneally to BALB/c mice, and peritoneal macrophages were collected at designated times. The phagocytotic activity of the peritoneal macrophages was assessed with regard to the uptake of latex beads by the cells. The time-course of phagocytotic activiy was shown to be correlated with the antigen-specific IgM antibody production. The phagocytotic activity was dependent on the dose of CEP, but was not influenced by peritoneal exudate cell number or the presence of antigen. The CEP-containing MLV increased the phagocytotic activity of peritoneal macrophages to a greater extent than SUV. In conclusion, it was demonstrated that the immuno-modulating activity of peritoneally injected CEP is closely related to the phagocytotic activity of peritioneal macrophages, that CEP-containing MLV exhibit greater stimulatory effect on the phagocytotic activity of macrophages than CEP-containing SUV, and that the immuno-modulating action of CEP is enhaced by incorporation into liposomes.
