Researchers from Dankook University in Korea tested their hypothesis that cinnamon bark (Cinnamomi Cortex Spissus), the dried bark of Cinnamomum cassia Blume (Lauraceae), and its components are effective against Alzheimer's disease (AD). The results of their study, which demonstrated the potential of cinnamon bark in reducing the production of the beta-amyloid protein, were published in the journal Nutrition Research.
Beta-amyloid is a protein associated with AD. It is synthesized by beta-secretase and gamma-secretase from amyloid precursor protein (APP) via the amyloidogenic pathway.
Inhibition of beta-amyloid production is a potential therapeutic approach to AD.
The researchers used methanol to obtain extracts from cinnamon bark and used open column chromatography and high-performance liquid chromatography for the bioassay-guided isolation of cinnamon bark extracts.
They isolated six phenylpropanoids from cinnamon bark: syringaresinol, medioresinol, coumarin, 2-hydroxycinnamaldehyde, cryptamygin A, and 3?,5,7-trimethoxy epicatechin.
The methanol extract was able to reduce beta-amyloid production in Chinese hamster ovarian cells stably expressing APP. They determined this using enzyme-linked immunosorbent assay.
Among the 6 phenylpropanoids, 4 microgram/milliliter (mL) medioresinol and cryptamygin A reduced beta-amyloid production by 50 and 60 percent, respectively.
They also decreased the amounts of beta-secretase and the proteolytic fragment of APP catalyzed by beta-secretase (sAPPbeta), suggesting that the anti-amyloidogenic activity of cinnamon bark comes from them.
Based on these results, the researchers concluded that cinnamon bark extracts contain potentially valuable anti-amyloidogenic agents for the prevention and treatment of AD.
Kang YJ, Seo DG, Park SY. PHENYLPROPANOIDS FROM CINNAMON BARK REDUCED ?-AMYLOID PRODUCTION BY THE INHIBITION OF ?-SECRETASE IN CHINESE HAMSTER OVARIAN CELLS STABLY EXPRESSING AMYLOID PRECURSOR PROTEIN. Nutrition Research. November 2016;36(11):1277–1284. DOI: 10.1016/j.nutres.2016.10.002