Low concentration of condensed tannins from catechu significantly inhibits fatty acid synthase and growth of MCF-7 cells

• Published in: Biochemical and biophysical research communications Vol. 371; no. 4; pp. 654 - 658
• Main Authors: Zhang, Shu-Yan, Zheng, Chao-Gu, Yan, Xi-Yun, Tian, Wei-Xi
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 11-07-2008
• Subjects: Areca - chemistry; Cancer; Cell Line, Tumor; Chemical Precipitation; Condensed tannin; Enzyme Inhibitors - isolation & purification; Enzyme Inhibitors - pharmacology; Fatty acid synthase; Fatty Acid Synthase, Type I - antagonists & inhibitors; Humans; Inhibition; Inhibitory Concentration 50; Tannins - isolation & purification; Tannins - pharmacology; Fatty acid synthase; Inhibition; Condensed tannin; Cancer
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2008.04.062

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
μg/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.