Combination of the anthocyanidins malvidin and peonidin attenuates lipopolysaccharide-mediated inflammatory gene expression in primary human adipocytes

We recently demonstrated that California table grapes and a methanol-extractable, polyphenol-rich fraction decreased adiposity, insulin resistance, or markers of inflammation in high-fat fed mice. Malvidin and peonidin glycosides were the 2 most abundant anthocyanins in the polyphenol-rich fraction. We hypothesized that a blood borne combination of anthocyanidins malvidin and peonidin derived from intestinal β-glycosidase metabolism of these 2 anthocyanins are responsible, in part, for the beneficial health effects observed in vivo. Therefore, we supplemented primary human adipocytes with malvidin or peonidin, alone or together, followed by acute lipopolysaccharide (LPS) treatment. Neither peonidin nor malvidin alone consistently decreased the expression of several inflammatory genes. However, supplementing adipocytes with an equal combination of malvidin plus peonidin followed by LPS treatment decreased the mRNA levels of interleukin (IL)-6, IL-1β, IL-8, monocyte chemoattractant protein-1, toll-like receptor-2, tumor necrosis factor alpha, cyclooxygenase-2, and interferon gamma-induced protein-10. The highest combination dose of malvidin plus peonidin decreased or increased the expression of protein tyrosine phosphatase-1B and hormone sensitive lipase, respectively, genes encoding proteins associated with insulin resistance or lipolysis. These data indicate that a combination of malvidin plus peonidin have potentiating interactions that reduce inflammatory gene expression; however, in vivo studies are needed to support these in vitro data.