Functional ingredient derived from processed brown rice extract activates human macrophage and promotes its shifting from mitochondrial to glycolytic energy metabolic activation

• Published in: Functional Food Science - Online ISSN: 2767-3146 Vol. 4; no. 4; pp. 153 - 165
• Main Authors: Takanashi, Keita, Dan, Katsuaki, Shinozuka, Tatsuo, Watanabe, Kenji, Jing, Yu, Tomobe, Koji
• Format: Journal Article
• Language: English
• Published: 19.04.2024
• ISSN: 2767-3146; 2767-3146
• DOI: 10.31989/ffs.v4i4.1322

Background: Brown rice (BR) has various beneficial effects. Recently, functional ingredient derived from processed BR (Kinmemai rice extract [KR-ex.]) has been developed in Japan, which reportedly decreases subjects’ “susceptibility to catching colds.” However, the effects of KR-ex. on the immune system remain unclear. Objective: This study aimed to examine the immunostimulant effects of KR-ex., focusing on the expression of activation markers and intracellular energy metabolic activity using human monocyte (U937)-derived macrophage cells. Methods: Cell activity was assessed using the gene expression of interleukin-1β and cyclooxygenase-2 as activation markers. The energy metabolic activity in mitochondria was evaluated using the expression of uncoupling protein 2 and the oxygen consumption rate, whereas that in glycolysis was evaluated using the expression of glucose transporter 1 and the amount of lactate released. Results: The results showed that the KR-ex. group had significantly higher expression of activation markers than the control group. Moreover, the KR-ex. group showed decreased mitochondrial metabolic activity and increased glycolytic metabolic activity compared to the control group. Conclusions: These results suggest that KR-ex. activates human macrophages and promotes the shifting of the intracellular energy metabolism from the mitochondria to glycolysis. Keywords: Brown rice; Functional ingredient; Immunostimulant effect; Macrophage; Intracellular energy metabolism; Mitochondria; Glycolysis