In this study, chicken FAS was used to measure the inhibitory activity as well as the inhibitory mechanism of garcinone E. In the present work, we found that garcinone E was a very potent FAS inhibitor with an IC50 value of 3.3 μM on the overall reaction of FAS, which was much lower than those of cerulenin (IC50 = 89 μM)30 and EGCG (IC50 = 52 μM).13 The strong inhibitory activity of garcinone E towards FAS, plus its edible plants source, opens up excellent prospects for its application as an anti-obesity and anti-cancer agent. The gene discussed is FAS; the disease is obesity due to melanocortin 4 receptor deficiency.