Figure 3.

α-Pinene inhibited the growth of CT-26 colon cancer allografts in BALB/c mice by increasing NK cytotoxicity. (a–c) Tumor volume and weight were significantly decreased by α-pinene 40 mg/kg treatment compared to the control (* p < 0.05, *** p < 0.005). (d) The cytotoxicity of mouse splenic NK cells was measured. Splenic NK cells were isolated from those of normal or tumor-transplanted mice and incubated with YAC-1 target cells prelabeled with calcein-AM as described in Section 4. Hank’s Balanced Salt Solution was used for spontaneous fluorescence from YAC-1 cells without effector NK cells, and total fluorescence was acquired from wells where YAC-1 cells were incubated with a lysis buffer. NK cell cytotoxicity was calculated as described in Section 4.