Figure 2.

Pathways regulating PPARγ-mediated adipocyte differentiation are shown on the left, while G-PCR targeted pathways working via cAMP-mediated signal transduction to regulate lipolysis are shown on the right. The pharmacologically targeted G-PCRs involved in lipolysis are GPR109a/HM74a or beta-adrenergic receptors. Nicotinic acid similarly affects both processes, inhibiting lipolysis and promoting adipocyte differentiation through PPARγ activation. However, nicotinic acid is also a precursor to NAD, which exerts the opposite effect (left). Resveratrol can both directly inhibit fatty acid synthase and cause activation of SIRT-1 activity, both of which are known to decrease fat content in adipocytes. Vaticanol B is an only just recently characterized tropical tree bark-derived resveratrol tetramer determined to have much greater anti-inflammatory activity than resveratrol. Thus, we predict that Vaticanol B may be similarly involved in controlling fat metabolism.