As it turns out, some flavones and isoflavones (polyphenolic phytochemicals belonging in the general class of flavoniods) that produce fat loss in animals may promote aromatase activity in humans. In particular, by elevating tissue cAMP levels through phosphodiestrase (PDE) inhibition, these flavones and isoflavones also stimulate aromatase activity in human gonads by increasing activity of cAMP-dependent alternative aromatase promoter enzymes p11 and 1.3. Usually, PDE metabolises cAMP. So PDE-inhibition boosts cAMP, leading to fat breakdown in adipose tissue. However, cAMP-boosting by these isoflavones and flavones also stimulates aromatise activity in some individuals. The isoflavone, genistein is a well known example. Forskolin, a well-known cAMP booster, appears to chart the same pathway in certain individuals.