Chemical characterization of cinnamon (Cinnamomum verum J. Presl) extracts and their capacities in weakening SARS-CoV-2 spike protein binding to ACE2, inhibiting ACE2 and scavenging free radicals

Authors: XIE, ZHUOHONG - University Of Maryland; LI, YANFANG - University Of Maryland; LIU, ZHIHAO - University Of Maryland; ZENG, MELODY - University Of Maryland; MOORE, JEFFERY - Collaborator; GAO, BOYAN - Shanghai Jiaotong University; Wu, Xianli; Sun, Jianghao; Wang, Thomas - Tom; Pehrsson, Pamela; He, Xiaohua; YU, LIANGLI (LUCY) - University Of Maryland

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/10/2023
Publication Date: 3/30/2023
Citation: Xie, Z., Li, Y., Liu, Z., Zeng, M., Moore, J., Gao, B., Wu, X., Sun, J., Wang, T.T., Pehrsson, P.R., He, X., Yu, L. 2023. Chemical characterization of cinnamon (Cinnamomum verum J. Presl) extracts and their capacities in weakening SARS-CoV-2 spike protein binding to ACE2, inhibiting ACE2 and scavenging free radicals. Journal of Agricultural and Food Chemistry. 71:4890-4900. https://doi.org/10.1021/acs.jafc.3c00285.
DOI: https://doi.org/10.1021/acs.jafc.3c00285

Interpretive Summary: Cinnamon (Cinnamomum verum J. Presl) bark and its extracts are popular ingredients added to food and supplement products. It has various health effects, including potentially preventing and treating corona virus disease-2019 (COVID-19). In our study, the cinnamon water and ethanol extracts were chemically characterized, and their potentials in weakening SARS-CoV-2 spike protein angiotensin converting enzyme 2 (ACE2) binding, reducing ACE2 availability, and scavenging free radicals were investigated. Twenty-seven and twenty-three compounds were tentatively identified in cinnamon water and ethanol extracts, respectively. Seven compounds were first reported in cinnamon. Cinnamon water and ethanol extracts weakened the binding of SARS-CoV-2 spike protein to ACE2 and inhibited ACE2 activity in a dose-dependent manner. Cinnamon ethanol extract showed strong free radical scavenging activities. The present study provides new evidence that cinnamon reduces the risk of SARS-CoV-2 infection and COVID-19 development.

Technical Abstract: Cinnamon (Cinnamomum verum J. Presl) bark and its extracts are popular ingredients added to food and supplement products. It has various health effects, including potentially preventing and treating coronavirus disease-2019 (COVID-19). In our study, the cinnamon water and ethanol extracts were chemically characterized, and their potentials in weakening SARS-CoV-2 spike protein- angiotensin-converting enzyme 2 (ACE2) binding, reducing ACE2 availability, and scavenging free radicals were investigated. Twenty-seven and twenty-three compounds were tentatively identified in cinnamon water and ethanol extracts, respectively. Seven compounds, including saccharumoside C, two emodin-glucuronide isomers, two physcion-glucuronide isomers and two type-A proanthocyanidin hexamers, were first reported in cinnamon. Cinnamon water and ethanol extracts weakened the binding of SARS-CoV-2 spike protein to ACE2 and inhibited ACE2 activity in a dose-dependent manner. Cinnamon ethanol extract had total phenolic content of 36.67 mg GAE/g and free radical scavenging activities against HO' and ABTS'+ as 1688.85, 882.88 µmol TE/g, which were significantly higher than that of the water extract as 24.12 mg GAE/g and 583.12 and 210.36 µmol TE/g. The free radical scavenging activity against DPPH' of cinnamon ethanol extract was lower than that of the water extract. The present study provides new evidence that cinnamon reduces the risk of SARS-CoV-2 infection and COVID-19 development.