Effects and mechanisms of active hexose correlated compound (AHCC) and genistein combined polysaccharide (GCP) in tumors

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Studies have demonstrated that GCP has anti-angiogenesis and apoptosis induction effects in tumor. On the other hand, AHCC can increase immunoreactivity by up-regulating cytokines such as IL-1, IL-2, IL-12, IFN-gama, TNF-alpha and enhancing the activities of macrophages, LAK and NK cells. Because both AHCC and GCP have shown anti-tumor activities, their synergistic anti-tumor effects are expected and investigated in vitro and in vivo in this study. Methods: 1. PC-3 cell line was cultured in RPMI1640 medium for 24 hrs, then, AHCC, GCP or AHCC plus GCP were added into the medium at the final concentration of 0.2 mg/mL medium. After 48 hours, the culture medium was collected and the proteins in the tumor cells were prepared for measuring VEGF by ELISA and Western Blotting, respectively. 2. PC-3 bearing nude mouse model: mice inoculated subcutaneously with 3 million parental PC-3 cells in 1/3 suspension in matrigel were randomized and split up into four groups of 8 mice each. The four groups were designed as control group, AHCC group, GCP group and combination group of AHCC and GCP, respectively. AHCC, GCP and AHCC plus GCP were prepared to 10% solution in water. All the mice of the four groups were daily treated with water, AHCC, GCP and AHCC plus GCP solution with the volume of 0.1 ml/10 gram body weight by oral from day 1 to 50, tumor volumes were measured twice a week. On day 50, the animals were humanely sacrificed, sera and peritoneal exudate cells (PEC) were collected and tumors were removed and subjected to extensive analysis. Results:AHCC and GCP inhibited tumor cell proliferation and tumor growth significantly, particularly the most effective activity was seen in the combination group. Other assays elucidated: (A) Down-regulating VEGF levels in tumor cells and tissues: AHCC and GCP treatment down-regulated levels, but the co-administration of AHCC and GCP showed more significant activity. (B) Up-regulating the protein expressions related to tumor inhibition genes: In this study, p21, p27 and PARP proteins were extracted from tumor tissues and were checked with Western blotting. The co-administration of AHCC and GCP regulated these genes obviously. (C) Enhancing the immune system: PEC was collected from tumor bearing mice and cultured in phenol red free RPMI1640 medium with 500 ng/ml LPS for 36 hours. Nitrogen oxide production was assayed by using Gries Reagent. As the result, AHCC treatment increased the production compared to the control group, but the co-administration of AHCC and GCP showed a much stronger effect than the group treated with AHCC alone. Conclusion:The synergistic effects of AHCC and GCP on tumors might base on down-regulating VEGF level, up-regulating tumor inhibition genes and enhancing immune systems.