4.10. In Vivo Tumor Xenograft Study

The in vivo antitumor activity of HGK against human NSCLC was studied while using six-week-old nude BALB/c nu/nu male mice (n = eight per group). The animals were inoculated subcutaneously in the right flank with H1975 tumor cells (3 × 10⁶) in 100 μL on day 0. Drug treatment was started when the tumor volume reached around 50 mm³ on day 10. The mice were randomized into control and drug treatment groups with eight animals in each group. The powder of HGK dissolved in 100 μL of PBS was administered by intra-peritoneal (i.p.) injection (1.0 mg/kg body weight) every two days. The control group was treated with an equal volume of PBS. The tumor volume was monitored every two days while using calipers, and tumor volume was estimated according to the following formula: tumor volume = length × width² /2. On day 17, the tumor-bearing mice was weighed and then sacrificed for the assay of tumor biology. The animals were also evaluated for body weights and consumption of food to access apparent signs of toxicity. All of the animal experiments were performed after obtaining the approval of the Institutional Animal Care and Use Committee (IACUC) of Chang Gung Memorial Hospital (IACUC approval no.: 2018031301, approval date: 6/19/2018).