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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: BACKGROUND, METHODS, RESULTS. Meshes: Animals, Antineoplastic Agents, Colorectal Neoplasms, Dose-Response Relationship, Drug, Drug Administration Schedule, HCT116 Cells, Humans, Male, Mastic Resin, Mice, Mice, SCID, Pistacia, Plant Extracts, Resins, Plant, Xenograft Model Antitumor Assays.
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Does a mastic gum extract induce suppression of growth of human colorectal tumor xenografts in immunodeficient mice? Context: We recently reported that ethanol and hexane extracts of the plant product, mastic gum (MG), contain constituents which can induce p53- and p21-independent G1-phase arrest followed by apoptosis of human HCT116 colon cancer cells in vitro. Herein, we extended these studies to investigate the in vivo anticancer activity of the hexane extract of MG (He-MG) against human colon tumor. The in vivo anticancer activity of He-MG was assessed in a human colon cancer/immunodeficient mouse model. Control and HCT116 tumor bearing SCID mice were injected intraperitoneally with He-MG at different administration schedules and doses ranging from 100 to 220 mg/kg body weight and tumor growth (size) was monitored. He-MG administered at a dose of 200 mg/kg administered daily for 4 consecutive days (followed by 3 days without treatment) inhibited tumor growth by approximately 35% in the absence of toxicity (side-effects) after 35 days.
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He-MG was found to possess antitumor activity against human colorectal cancer under the experimental conditions of this study. The extent of suppression and toxicity by a specific He-MG dose depends on the schedule of administration. Final Decision: yes