Based on the potential of
Schiff base compounds to act as sources for the development of
cancer chemotherapeutic agents, this in vivo study was performed to investigate the inhibitory properties of the synthetic
Schiff base compound Cu(BrHAP)2 on colonic
aberrant crypt foci (ACF).
METHODOLOGY: This study involved five groups of male rats. The negative control group was injected with
normal saline once a week for 2 weeks and fed 10%
Tween 20 for 10 weeks, the
cancer control group was subcutaneously injected with 15 mg/kg
azoxymethane once per week for two consecutive weeks, the positive control group was injected with 15 mg/kg
azoxymethane once per week for two consecutive weeks and 35 mg/kg
5-fluorouracil (injected intra-peritoneally) for 4 weeks, and the experimental groups were first injected with 15 mg/kg
azoxymethane once per week for two consecutive weeks and then fed 2.5 or 5 mg/kg of the
Schiff base compound once a day for 10 weeks. Application of the
Schiff base compound suppressed total colonic ACF formation by up to 72% to 74% (P<0.05) when compared with the
cancer control group. Analysis of colorectal specimens revealed that treatments with the
Schiff base compound decreased the mean crypt scores in
azoxymethane-treated rats. Significant elevations of
superoxide dismutase,
glutathione peroxidase and
catalase activities and a reduction in the level of
malondialdehyde were also observed. Histologically, all treatment groups exhibited significant decreases in dysplasia compared to the
cancer control group (P<0.05). Immunohistochemical staining demonstrated down-regulation of the
PCNA protein. Comparative western blot analysis revealed that COX-2 and Bcl2 were up-regulated and Bax was down-regulated compared with the AOM control group.
CONCLUSION: