Abstract
Carnosic acid (CA) is recognized as a unique neuroprotective compound in the herb rosemary, since it induces expression of antioxidant enzymes including heme oxygenase-1 (HO-1), γ-glutamylcysteine synthase (γ-GCS), and glutathione S-transferase (GST) via activation of nuclear factor erythroid 2-related factor 2 (Nrf2), which is a nuclear transcription factor. In this study, we examined the cytoprotective effects of CA against starvation. We found that CA protected starvation-induced SH-SY5Y cell death by activating Akt and extracellular signal-regulated kinase 1/2 (Erk1/2). Interestingly, CA induced moderate autophagy and dephosphorylation of a transcriptional factor, the forkhead box protein O3a (FoxO3a). These effects of CA play an important role in cytoprotection.
Disclosure statement
S. S., S. M., T. Kawaoka, and K. M. have filed a patent on the use of CA as FoxO3a activating agent (Japan Patent Application: P2015-000439).
Funding
This work was supported by Grant-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology of Japan [22580130 and 26450159] (S. M. and K. M.).