Antioxidant and anti-inflammatory activities of pyranoanthocyanins and other polyphenols from staghorn sumac (Rhus hirta L.) in Caco-2 cell models

Abstract The antioxidant and anti-inflammatory activities of the novel pyranoanthocyanins and other polyphenols from staghorn sumac ( Rhus hirta L.) were examined. The results not only confirmed the previously found antioxidant activity by chemical based assays, but more importantly strong anti-inflammatory activity for the first time in cell-based assays. These unique compounds significantly inhibited the production of pro-inflammatory cytokine IL-8 production stimulated by H 2 O 2 and TNF-α. It was also found that these activities of the crude extract were primarily from the individual polyphenols, particularly the unique pyranoanthocyanins and 7-methoxyanthocyanins. Pyranoanthocyanin 1 , in particular, showed a markedly strong anti-inflammatory activity at 1 M, followed by pyranoanthocyanin 2 and a 7-methoxyanthocyanin 5 . Further mechanism investigation showed that the anti-inflammatory activity was likely mediated through inhibition of NF-κB activation via phosphorylation of IκBα. Results from the present study warrant further investigation into the in vivo anti-inflammatory effect and health benefits using animal models or human subjects.