Polyphenols as reactive carbonyl species scavengers-The solution to the current puzzle of polyphenols' health effects.

Evidence from epidemiological analysis confirmed the protective effects of polyphenol-rich foods or beverages from certain chronic diseases, however, a direct antioxidant effect is not fully feasible when considering for the real in vivo behavior of polyphenols. Polyphenols have a limited bioavailability and only low concentrations are present in the systemic circulation compared with other endogenous and exogenous antioxidants, besides, how polyphenol can enter tissue (especially brain) and cells were not answered yet. There is investigation showed that reactive carbonyl species (RCS), which accumulated in circulatory system and tissue, also plays a significant role in the etiology and progression of certain chronic diseases. In the effort of searching for nontoxic trapping agents of RCS from dietary sources, some natural polyphenols have been found to have reactivity with RCS, It should be realized that polyphenols are versatile bioactive rather than mere antioxidants. We present here the hypothesis that polyphenols acting as RCS scavengers maybe the supplementary and reasonable mechanism for the puzzle of polyphenols' health effects.