Nelumbo nucifera Leaves Prevent NMU-Induced Mammary Tumor through Downregulation of Fatty Acid Synthase, Estrogen Receptor-α and Her2 Expression.

Diet polyphenol can reportedly prevent the formation of breast-cancer cells. Nelumbo nucifera leaf extract (NLE) is enriched with polyphenols and has several cellular functions, such as anti-atherosclerosis, anti-inflammation, and antitumor. In this study, we investigated the role of NLE in the prevention of N-methyl-N-nitrosourea (NMU)-induced mammary tumor formation. Cotreatment with NLE significantly reduced the NMU-induced tumor incidence, number, and volume. NLE administration significantly repressed the tumor growth and weight of nude mice upon inoculation with BT-474 cancer cells. Immunohistochemical staining indicated that fatty acid synthetase, estrogen receptor (ER)-α, and phosphorylated ER-α were obviously reduced in the cancer part of BT-474 inoculated nude mice upon administration of 2% NLE. Western blot analysis revealed that NLE and NLPE (polyphenol-rich NLE) repressed ER-α expression and phosphorylation and decreased the phosphorylation of Her-2 without affecting their expression. Overall, NLE and NLPE exhibited more effective antitumor abilities in NMU-induced mammary cancer formation than with tamoxifen and Herceptin.