RESUMO
The present study was undertaken to investigate the chemopreventive efficacy of the ethanolic extract of indigenous Nigella sativa [NsE] seeds during the initiation phase of 1,2- dimethylhydrazine [DMH]-induced colon carcinogenesis in a rat model, and to appraise its potential impact on cellular proliferation. The results demonstrated that [NsE], at an orally daily dose equivalent to 150 mg of the seeds/kg body weight, has an inhibitory effect against colon carcinogenesis as reflected by significant reductions in tumor incidence, multiplicity and mean tumor volumes. These reductions were accompanied by a significant decrease in colonic proliferating cell nuclear antigen-Labeling index [PCNA-LI]. In conclusion, we provided evidence that [NsE] has a chemopreventive effect against DMH- induced colon carcinogenesis. We surmise that such effect of [NsE] is mediated, at least in part, through its ability to suppress cellular proliferation. The results could provide an effective chemopreventive approach in the primary prevention of colon cancer in humans in the next future