Anthocyanins from colored maize ameliorated the inflammatory paracrine interplay between macrophages and adipocytes through regulation of NF-κB and JNK-dependent MAPK pathways

Abstract

This study aimed to investigate the anti-inflammatory effect of two anthocyanin-rich extracts from purple (PMW) and red maize (RMW), in comparison to three pure anthocyanins [cyanidin-3-O-glucoside (C3G); peonidin-3-O-glucoside (P3G); pelargonidin-3-O-glucoside (Pr3G)] on the inflammatory states that occurred during the macrophage-adipocyte interaction, using both mono- and co-culture in vitro models. PMW and RMW reduced production of pro-inflammatory cytokines (TNF-α: −8.8% to −44.2%; MCP-1: −18.4% to −56.9%) in both macrophages and adipocytes mono-cultures. PMW and RMW, as well as C3G and Pr3G inhibited activation of NF-κB and JNK pathways, via regulation of phosphorylation of IκBα and JNK, respectively. Both extracts and pure anthocyanins restored inflammation-mediated oxidative stress and insulin resistance in macrophage-conditioned media-treated adipocytes. PMW and RMW decreased pro-inflammatory cytokine production and lipolysis, while enhanced the glucose transporter 4 membrane translocation in the adipocyte-macrophage co-cultures. These results suggested that colored maize anthocyanins could potentially ameliorate the paracrine interplay between adipocytes and macrophages.