Antitumor activity study in in vivo xenograft animal model

Seven-week-old male BALB/C nude mice were purchased from Orient-Bio (Seongnam, Gyunggi, Korea). The mice were maintained in accordance with the Korea Food and Drug Administration guidelines as well as the regulations for the care and use of laboratory animals of the animal ethics committee of Chungbuk National University (CBNU-278-11-01). HCT116 colon cancer cells were injected subcutaneous (1 x 10⁷ cells / 0.1 mL PBS/animals) with a 27-gauge needle into the right lower flanks in carrier mice. After 14 days, when the tumors had reached an average volume of 100-150 mm³, the tumor-bearing nude mice were intraperitoneally (i.p.) injected with MMPP (2.5 mg/kg and 5 mg/kg dissolved in 0.01% DMSO) twice per week for 3 weeks. The group treated with 0.01% DMSO was designated as the control. The weight and tumor volume of the animals were monitored twice per week. The tumor volumes were measured with vernier calipers and calculated by the following formula: (A x B²)/2, where A is the larger and B is the smaller of the two dimensions. At the end of the experiment, the animals were sacrificed. The tumors were separated from the surrounding muscles and dermis, excised and weighed.