17. The Mechanism of AHCC and GCP on Tumors

A) Down-regulating VEGF levels in tumor cells and tumor tissues

PC-3 cell line was cultured in RPMI1640 medium for 24 hrs, then, AHCC, GCP or AHCC plus GCP were added into the medium to the final concentration of 200μg/ml medium. After culturing for another 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. The results were as follows.

AHCC and GCP treatment down-regulated VEGF levels, but the co-administration of AHCC + 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. As shown in the pictures above, the co-administration of AHCC and GCP regulated these genes that control the apoptosis occurring in tumor tissues.

Seen from above photographs, apoptosis happened only in approximately 1-3% of tumor cells in the control group, but about 30% of the cells were shown to be apoptotic in the AHCC-treated group. In GCP and AHCC + GCP-treated groups, near 50% of tumor cells became apoptotic.

C.) Enhancing the immune system

When the PC-3 bearing mice were sacrificed, PEC (peritoneal exudate cells) were collected and cultured in phenol red free RPMI1640 medium with 500ng/ml LPS for 36 hours. NO (nitrogen oxide) production was assayed by using Gries Reagent. As shown in Figure 14, AHCC treatment increased NO production compared to the control group, but the co-administration of GCP+AHCC showed a much stronger effect than the group treated with AHCC alone.

In summary, AHCC and GCP alone appeared to have marked inhibitory effects on prostate cancer cells, but the co-administration of AHCC + GCP showed a synergistic effects against the cancer. The mechanisms might be:

1) Down-regulating of VEGF expression in serum, tumor cells and tissues.

2) Up-regulation of p21, p27 and PARP expression.

3) Enhancement of the immune system.

4) Induced apoptosis in tumor cells and tumor tissues.

Some possible explanations why the co-administration of AHCC and GCP showed a synergistic effect on cancers, could be that at first, GCP up-regulates tumor-inhibitory genes and down-regulates VEGF levels so that apoptosis occurs in tumors. Once tumors become smaller, the tumor can be cleared by the immune system which is significantly enhanced by AHCC.