Anti-inflammatory activity of natural stilbenoids: A review
Resveratrol and other natural stilbenoids, including piceatannol, pterostilbene, and gnetol, are well-known anti-inflammatory compounds with indisputable activity in vitro as well as in vivo. Their molecular targets include inducible nitric oxide synthase, cyclooxygenases, leukotrienes, nuclear factor kappa B, tumor necrosis factor α, interleukins and many more. This anti-inflammatory activity together with their antioxidant activity is believed to stand behind their other positive health effects against cancer, cardiovascular and neurodegenerative diseases or diabetes. Thus, they are nowadays commercially marketed as nutraceuticals. Naturally, they are present in wine, grapes or berries. However, there is a rigorous debate about the real effect of these compounds on human health. It is argued that the concentration of stilbenoids in food and beverages is too low to have any therapeutic potential and this concentration is further reduced by their low bioavailability and extensive metabolism. Therefore, this review focuses on in vitro, in vivo, preclinical as well as clinical data available for various natural stilbenoids and summarizes the anti-inflammatory targets on molecular level, compares the relevance of the experimental studies, discusses the metabolism of stilbenoids and the potential activity of their metabolites and relates this knowledge to human health. Moreover, the ways to augment stilbenoidsí efficacy are suggested with special focus on multitargeted therapy and nanocarriers.