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Macrophage activation by polysaccharide biological response modifier isolated from Aloe vera L. var. chinensis (Haw.) Berg.

Department of Biochemistry, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR, People's Republic of China.
International Immunopharmacology (Impact Factor: 2.71). 12/2006; 6(11):1634-41. DOI: 10.1016/j.intimp.2006.04.013
Source: PubMed

ABSTRACT A mannose-rich polysaccharide biological response modifier (BRM), derived from Aloe vera L. var. chinensis (Haw.) Berg., was demonstrated to be a potent murine B- and T-cell stimulator in our previous study. We here report the stimulatory activity of PAC-I on murine peritoneal macrophage. The polysaccharide when injected into mice enhanced the migration of macrophages to the peritoneal cavity. Peritoneal macrophage when treated by PAC-I in vitro had increased expression of MHC-II and FcgammaR, and enhanced endocytosis, phagocytosis, nitric oxide production, TNF-alpha secretion and tumor cell cytotoxicity. The administration of PAC-I into allogeneic ICR mice stimulated systemic TNF-alpha production in a dose-dependent manner and prolonged the survival of tumor-bearing mice. PAC-I is thus a potent stimulator of murine macrophage and the in vitro observed tumoricidal properties of activated macrophage might account for the in vivo antitumor properties of PAC-I. Our research findings may have therapeutic implications in tumor immunotherapy.

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