Nelumbo nucifera leaf polyphenol extract inhibits breast cancer cells metastasis in vitro and in vivo through PKCα targeting

Nelumbo nucifera Gaertn. has long been used in food and traditional herbal medicine in Asia. It exhibits several biological properties including antitumor, antiangiogenic, antiobesity, and antioxidant properties. However, the active components and mechanisms underlying the effects of N. nucifera leaf extract (NLE) on breast tumor migration remain undefined. We found that NLE and N. nucifera leaf polyphenol extract (NLPE) significantly attenuated migration in MDA-MB-231 and 4T-1 breast cancer cells. The treatment of cells with NLE and NLPE suppressed the expression of RhoA, Rac1, and Cdc42. Furthermore, the activation of ERK and p38 MAPK was inhibited by NLE and NLPE. Notably, NLE and NLPE treatment significantly reduced the activation of protein kinase C α and the lung metastasis of breast cancer in vivo. Overall, our findings illustrate the roles of NLE and NLPE in breast cancer cell migration, suggesting that NLE and NLPE are potential chemopreventive agents for breast cancer metastasis.