Herbal formulae with black pepper have been used to cancer treatment. The aim of this work was to evaluate antitumor activity of ethanolic and high pressure extracts produced from black pepper (Piper nigrum L. cultivar Bragantina). The high pressure extracts were obtained by Supercritical Fluid extraction (SFE) at different conditions. Phytochemical analysis of the extracts showed the presence of piperine and terpenoids. However, the extract at 200 bar and 40 degrees C (SFE200) had higher piperine content and lowest monoterpenes/sesquiterpenes ratio, compared to others extracts, and also presented more cytotoxicity after 72 h (EC50 14.40 +/- 3.30 pg/ml), probably due the synergy between piperine and sesquiterpenes. The SFE200 contain phytocompounds able to intercalate causing oxidative DNA damage. In vivo treatment with 10 mg/kg/day of SFE200 for isogenic Balb-c mice bearing Ehrlich ascites carcinoma showed higher tumor inhibition and increased the survival time compared to ethanolic extract, probably related to the cell cycle arrest and apoptosis.