Hypoestoxide inhibits tumor growth in the mouse CT26 colon tumor model.
OBJECTIVE
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 mm(3), 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 B16F(1) 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 mm(3) vs 1542.8 mm(3), 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.


CONCLUSIONS
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.
Ojo-Amaize
Emmanuel A
EA
Immune Modulation Inc, Bloomington, CA 92316-0998, USA. ojoamaize@aol.com
Cottam
Howard B
HB
Oyemade
Olusola A
OA
Okogun
Joseph I
JI
Nchekwube
Emeka J
EJ
D000284:Administration, Oral; D000818:Animals; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology* / Q000627:therapeutic use; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D003110:Colonic Neoplasms / Q000188:drug therapy* / Q000473:pathology; D004224:Diterpenes / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage; D051379:Mice; D008807:Mice, Inbred BALB C; D009374:Neoplasms, Experimental / Q000188:drug therapy / Q000473:pathology; D013997:Time Factors
D004224:Diterpenes; C432343:hypoestoxide; D005472:Fluorouracil