Rosmarinic acid suppresses tau phosphorylation and cognitive decline by downregulating the JNK signaling pathway

Rosmarinic acid (RA), a polyphenol in Lamiaceae herbs, is a candidate preventive ingredient against Alzheimer’s disease (AD) due to potent inhibition of amyloid β (Aβ) aggregation, but its effects on tau phosphorylation and cognitive dysfunction were unclear. This study shows that dietary RA inhibits AD hallmarks—Aβ and phosphorylated tau accumulation—and improves cognition in the 3×Tg-AD mouse model. RA intake suppressed hippocampal inflammation and downregulated the JNK signaling pathway that induces tau phosphorylation. RA exerted anti-inflammatory effects in both central and peripheral tissues. Downregulation of hippocampal JNK signaling may underlie the inhibition of pathological progression and cognitive deficits by RA feeding.

So Yamamoto, Tomoko Kayama, Moeko Noguchi-Shinohara, Tsuyoshi Hamaguchi, Masahito Yamada, Keiko Abe, Shoko Kobayashi