Combined LUT and I3C suppress breast cancer tumor growth in MCF7 cells-derived xenograft mice. (A) Schematic experimental design of MCF7 xenograft mice generation and treatments. MCF7 cells were mixed with Matrix-gel and implanted into the mammary fat pad. When tumor size reached about 50-100 mm3, xenograft mice were randomly grouped to receive vehicle (5% DMSO, 5% Tween 20, 90% PBS), LUT (10 mg/kg/day), I3C (20 mg/kg/day), or the combination of LUT and I3C (LUT 10mg/kg/day + I3C 20mg/kg/day) by i.p injection every other day for 5 weeks. (B) Tumors from all groups. Scale bar represents 1 cm. (C) No effects on body weight. Combined LUT and I3C synergistically inhibited tumor volume/size (D) and weight (E) in MCF7 xenograft mice. (F) Combined LUT and I3C synergistically inhibited tumor Erα, CDK6, and CDK4 protein expression. Target protein expression was normalized by GAPDH. The VEH, LUH, I3C and LCI were the same samples on the same membrane and share the same GAPDH bands, after detecting one protein, the membrane was stripped and reprobed the second or third proteins. Data are means ± SEM of the animals. N = 6–7. * p < 0.05; ** p < 0.01.