title: Low concentration of condensed tannins from catechu significantly inhibits fatty acid synthase and growth of MCF-7 cells.
abstract: Tannins exist widely in plants, but because they precipitate proteins, scientists frequently ignore them in search of bioactive components. Catechu, a traditional astringent, is rich in tannins. In this study, we found that condensed tannins from catechu potently inhibited animal fatty acid synthase (FAS). Among them, trimeric condensed tannin showed the most potent inhibition with IC(50) of 0.47 microg/ml and it also exhibited strong time-dependent inhibition. Its inhibitory kinetics and reacting sites on FAS were obviously different from the known inhibitors of FAS. Furthermore, condensed tannins were found to suppress the growth of MCF-7 breast cancer cells, and the effect was related to their activity of FAS inhibition. The inhibition of both FAS activity and MCF-7 growth was exhibited by low concentrations of condensed tannins without FAS being precipitated. These results suggest tannins would be a valuable resource of bioactive substances.
authors.affiliation: College of Life Science, Graduate University of Chinese Academy of Sciences, P.O. Box 4588, Beijing 100049, PR China.
authors.forename: Shu-Yan
authors.initials: SY
authors.lastname: Zhang
authors.forename: Chao-Gu
authors.initials: CG
authors.lastname: Zheng
authors.forename: Xi-Yun
authors.initials: XY
authors.lastname: Yan
authors.forename: Wei-Xi
authors.initials: WX
authors.lastname: Tian
mesh_terms: D001114:Areca / Q000737:chemistry*; D045744:Cell Line, Tumor; D011232:Chemical Precipitation; D004791:Enzyme Inhibitors / Q000302:isolation & purification / Q000494:pharmacology*; D054890:Fatty Acid Synthase, Type I / Q000037:antagonists & inhibitors*; D006801:Humans; D020128:Inhibitory Concentration 50; D013634:Tannins / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D004791:Enzyme Inhibitors; D013634:Tannins; C518729:FASN protein, human; D054890:Fatty Acid Synthase, Type I