R1-barrigenol—a tea sapogenin—suppresses the lipopolysaccharide-induced inflammatory response in microglial cells

• Published in: Food Science and Technology Research Vol. 30; no. 3; pp. 419 - 430
• Main Authors: Hayashi, Ryotaro, Fukumitsu, Satoshi, Aida, Kazuhiko, Kobayashi, Shoko
• Format: Journal Article
• Language: English
• Published: Tsukuba Japanese Society for Food Science and Technology 2024; Japan Science and Technology Agency
• Subjects: Camellia sinensis; Gene expression; Green tea; inflammation; Inflammatory response; Lipopolysaccharides; Lymphocytes B; Microglia; Neurodegenerative diseases; Phosphorylation; Polarization; Polypeptides; R1-barrigenol; sapogenin; Sapogenins
• ISSN: 1344-6606; 1881-3984
• DOI: 10.3136/fstr.FSTR-D-23-00246

Certain natural components are effective against inflammation, a hallmark of neurodegenerative disease progression. Although green tea contains sapogenins, their effects on brain function remain unknown. Herein, we focused on R1-barrigenol (R1B)—a major tea sapogenin—and evaluated its anti-inflammatory effects on mouse microglia. R1B treatment decreased mRNA and protein expression levels of inflammatory cytokines in lipopolysaccharide (LPS)-treated mouse microglia compared with those in LPS-treated control microglia. R1B reduced the mRNA expression of M1-type microglia markers and phosphorylation levels of nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor-alpha. These results suggest that R1B suppresses LPS-induced nuclear factor κ-light-chain-enhancer of activated B signaling, a regulator of M1-type polarization. Therefore, it is suggested that R1B may reduce inflammatory responses by suppressing M1 polarization-type changes, and that R1B may exhibit preventive and therapeutic effects against neurodegenerative diseases.