Amentoflavone is a mixed Phosphodiesterase (PDE) inhibitor [2-7]. Many of you are familiar with forskolin, which derives its utility in fat loss from its ability to increase cAMP levels in appropriate tissues, specifically adipose (fat) tissue. And many of you are familiar with, say, ephedrine, which acts as a b2 agonist to ultimately increase levels of intracellular cAMP. The final common pathway with both forskolin and ephedrine is the increase in cAMP in fat cells, which results in the subsequent activity of various kinases and transcription factors in inducing cascades that promote lipolysis, or the breakdown of stored fat. As mentioned above, amentoflavone inhibits PDE, and PDE is responsible for the breakdown of cAMP. So by blocking PDE with amentoflavone, we increase cAMP and thus increase fat loss as well. Here’s a simplified model:
A “(-)” denotes the inhibition of an enzyme/pathway, while a “(+)” denotes stimulation of an enzyme or pathway. As you can see, amentoflavone acts downstream of both ephedrine and forskolin to block the PDE enzyme. In simple terms, you get a “double negative” at cAMP levels, resulting in a positive (net) increase. This results in stimulation of the next step: “fat loss.”
Interestingly enough, each compound listed above (ephedrine, yohimbine, forskolin, amentoflavone) acts on a different step of the fat loss pathway, and in theory, these could all be combined for a synergistic effect.