Published online Sep 14, 2007. doi: 10.3748/wjg.v13.i34.4586
Revised: June 23, 2007
Accepted: June 30, 2007
Published online: September 14, 2007
AIM: To evaluate the effect of the natural diterpenoid, hypoestoxide (HE) on the growth of established colon cancer in mice.
METHODS: The CT26.WT mouse colon carcinoma cell line was grown and expanded in vitro. Following the expansion, BALB/c mice were inoculated s.c. with viable tumor cells. After the tumors had established and developed to about 80-90 mm3, the mice were started on chemotherapy by oral administration of HE, 5-fluorouracil (5-FU) or combination.
RESULTS: The antiangiogenic HE has previously been shown to inhibit the growth of melanoma in the B16F1 tumor model in C57BL/6 mice. Our results demonstrate that mean volume of tumors in mice treated with oral HE as a single agent or in combination with 5-FU, were significantly smaller (> 60%) than those in vehicle control mice (471.2 mm3vs 1542.8 mm3, P < 0.01). The significant reductions in tumor burden resulted in pronounced mean survival times (MST) and increased life spans (ILS) in the treated mice.
CONCLUSION: These results indicate that HE is an effective chemotherapeutic agent for colorectal cancer in mice and that HE may be used alone or in combination with 5-FU.