2.18. Xenograft Experiment

For the nude mice xenograft tumor assay, 3.6 ×10⁷ T24 cells/mL were suspended in 100 µL PBS and mixed with 100 µL BD Matrigel matrix (BD Biosciences, NJ, USA); this solution was then injected subcutaneously into the back of male BALB/c nude mice (7-week-old; weight, 23–28 g). The mice were randomly divided into five groups (n = 6) when the tumor volume reached an average size of 200–400 mm³. Tumor volume was measured every 2 or 3 days using Vernier calipers and calculated using the formula (Tumor volume (TV) = (W² × L)/2). Vehicle alone (methanol), MSSV (1, 5, and 15 mg/kg) were orally administered daily for 15 days and cisplatin (5 mg/kg) was intraperitoneally injected daily for 12 days. The general condition and body weight of mice were monitored daily. Tumor inhibition rate (%) was calculated using the formula (mean tumor weight of vehicle group−mean tumor weight of experiment group)/mean tumor weight of vehicle group ×100).