Procyanidin C1 (PCC1), a natural polyphenol with oral activity, causes DNA damage, cell cycle arrest and induces apoptosis. Procyanidin C1 decreases the level of Bcl-2, but enhances BAX, caspase 3 and 9 expression in cancer cells. Procyanidin C1 shows senotherapeutic activity and increases lifespan in mice[2].IC50 & Target:IC50: 31.5 μg/mL (MCF-7), 36.6 μg/mL (MDA-MB-231)In Vitro:Procyanidin C1 (6.25-100 μg/mL; 48 h) shows cytotoxic activities to MCF-7 and MDA-MB-231 cells.Procyanidin C1 (35 μg/mL; 48 h) affects cell cycle of MCF-7 and MDA-MB-231 cancer cells.Procyanidin C1 significantly up-regulates Chk 1 and Chk 2 in MCF-7 and MDA-MB-231 cancer cells.Procyanidin C1 (27.85 and 66.41 μL) induces significant DNA damage in MCF-7 and MDA-MB-231 cancer cells.Procyanidin C1 (45 μg/mL; 72 h) reduces the expression level of Bcl-2 but increases the expression level of BAX, and increases activities of caspase 3 and 9 to induces cell apoptosis of MCF-7 and MDA-MB-231 cancer cells.In Vivo:Procyanidin C1 (20 mg/kg; i.p.; 2 weeks after the first MIT dose and then delivered biweekly) increases tumour regression[2].Procyanidin C1 (20 mg/kg; i.p.; for 7 d) shows senolytic efficacy in mice with senescent mouse embryonic fibroblasts injection[2].Procyanidin C1 (20 mg/kg; p.o.; for 3 d) increases the lifespan of old mice[2].