Antiinflammatory effect of the ethanolic extract of Korean native herb Potentilla rugulosa Nakai in Bisphenol-a-stimulated A549 cells

Potentilla rugulosa Nakai (P. rugulosa) is a perennial herb in the Rosaceae family and found in the Korean mountains. Previously, our findings demonstrated that P. rugulosa contains numerous polyphenols and flavonoids exhibiting important antioxidant and anti-obesity bioactivities. Bisphenol A (BPA) is a xenoestrogen that was shown to produce pulmonary inflammation in humans. However, the mechanisms underlying BPA-induced inflammation remain to be determined. The aim of this study was to examine whether ethanolic extract of P. rugulosa exerted an inhibitory effect on BPA-induced inflammation utilizing an adenocarcinoma human alveolar basal epithelial cell line A549. The P. rugulosa extract inhibited BPA-mediated cytotoxicity by reducing levels of reactive oxygen species (ROS). Further, P. rugulosa extract suppressed the upregulation of various pro-inflammatory mediators induced by activation of the nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways. In addition, inhibition of the NF-κB and MAPK signaling pathways by P. rugulosa extract was found to occur via decrease in the transcriptional activity of NF-κB. Further, blockade of phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and stress-activated protein kinase/Jun N-terminal kinase (SAPK/JNK) was noted. Thus, our findings suggest that the ethanolic extract of P. rugulosa may act as a natural anti-inflammatory therapeutic agent.