Suppression of inflammatory responses by black rice extract in RAW 264.7 macrophage cells via downregulation of NF-kB and AP-1 signaling pathways

• Main Authors: Pornngarm Limtrakul, Supachai Yodkeeree, Pornsiri Pitchakarn, Wanisa Punfa
• Format: Journal
• Published: 2018
• Subjects: Agricultural and Biological Sciences
• Online Access: https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84930714532&origin=inward; http://cmuir.cmu.ac.th/jspui/handle/6653943832/44559
• Institution: Chiang Mai University

Anthocyanin, a phenolic compound, has been reported to have an anti-inflammatory effect against lipopolysaccharide (LPS) induced changes in immune cells. However, little is known about the molecular mechanisms underlying its anti-inflammatory effects. Few research studies have concerned the anti-inflammation properties of colored rice extract as a functional material. Therefore, the purpose of this study was to examine anti-inflammatory effects of the polar fraction of black rice whole grain extracts (BR-WG-P) that features a high anthocyanin content. Our results showed that BR-WG-P significantly inhibited LPS-induced proinflammatory mediators, including production of NO and expression of iNOS and COX-2. In addition, secretion of pro-inflammatory cytokines including TNF-a and IL-6 was also significantly inhibited. Moreover, BR-WG-P and anthocyanin inhibited NF-kB and AP-1 translocation into the nucleus. BR-WG-P also decreased the phosphorylation of ERK, p38 and JNK in a dose dependent manner. These results suggested that BR-WG-P might suppress LPS-induced inflammation via the inhibition of the MAPK signaling pathway leading to decrease of NF-kB and AP-1 translocation. All of these results indicate that BR-WG-P exhibits therapeutic potential associated with the anthocyanin content in the extract for treating inflammatory diseases associated with cancer.