CYTOTOXIC AND ANTITUMOR EFFECT OF THE ETHANOLIC EXTRACT OF THE BARK OF HIMATANTHUS BRACTEATUS (A. DC.) WOODSON

Introduction Himatanthus bracteatus has been popularly used in the treatment of cancer, but its antitumor properties have not been scientifically reported yet. Objectives The purpose of this study was to assess the antitumor effect of Himatanthus bracteatus ethanolic extract (HBEE) in mice. Design The HBEE was obtained under high pressure conditions (100 bar, 2 mL/min, 25°C) and its cytotoxic activity was assessed in vitro against MCF-7 and MCF-10 A cells. For the biologic assay, 180 sarcoma cells were transplanted into 40 mice assigned into 5 groups: CTR, 5-fluorouracil (5-FU), and HBEE10, 30, and 100 (treated with saline, 5-FU, and HBEE at 10, 30, and 100 mg/Kg, respectively). Hematologic and biochemical analyses, as well as gross and morphologic analyses of the tumors, were performed in order to evaluate the toxicologic aspects. Results The IC50 of HBEE for MCF-7 tumor cells (36.28 µg/mL) was significantly higher than for MCF-10 A nontumor cells (145.13 µg/mL). In vivo assay demonstrated that HBEE at 30 mg/Kg significantly reduced tumor weight (P Conclusions These data suggest that the HBEE exerted selective cytotoxic for tumor cells and antitumor activity comparable to 5-FU.