Abstract: Objective To explore the effects of lycium barbarum polysaccharide (LBP) on restraining the mouse pancreatic cancer cells LTPA by the polarization of macrophages to type 1 macrophages (M1). Methods LTPA tumor model of the subcutaneous CB-17SCID mice was constructed. Model mice were randomly divided into tumorbearing model group (n=10) and LBP treatment group (n=10). The LBP treatment group was fed 10mg/kg LBP every day, and the tumor-bearing model
group was fed the same dose of normal saline. The same amount of macrophages Raw264.7 was randomly divided into the control group and experimental groups (different concentrations of LBP). MTT assay was used to detect the optical density (OD) of Raw264.7 in experimental groups and control group. ELISA was used to detect the levels of the interleukin (IL)-12 and IL-10 in experimental group (LBP was 100 mg/L) and the control group. Flow cytometry was used to test the levels of the
membrane protein CD16/32 and CD206 in experimental group (LBP was 100 mg/L) and the control group. The tumor mass was weighted and the volume was calculated after three weeks. The effects of LBP on the growth of subcutaneous tumor were detected. HE staining and KI-67 staining were used to detect the microscopic changes of tumor and the proliferation of the LTPA. Results The dose of 100 mg/L LBP can promote the growth of the macrophages Raw264.7 (P < 0.01), and induced the high expression of CD16/32 and low expression of CD206, high secretion of IL- 12 and low secretion of IL- 10. The weight, volume of the tumor and the expression of KI-67 were significantly lower in experimental group than those in the control group (P < 0.01). The microscopic necrosis area range of tumor was larger than that of control group. Conclusion The LBP has the effect of restraining LTPA by the polarization of macrophages to M1.

Key words: macrophages, pancreatic neoplasms, lycium barbarum polysaccharide, the polarization of macrophages, anti-tumor about pancreatic cells, type 1 macrophages, type 2 macrophages