Chemical composition of honeysuckle (Lonicerae japonicae) extracts and their potential in inhibiting the SARS-CoV-2 spike protein and ACE2 binding, suppressing ACE2, and scavenging radicals

Authors: GAO, BOYAN - Shanghai Jiaotong University; ZHU, LIN - Shanghai Jiaotong University; LIU, ZHIHAO - University Of Maryland; LI, YANFANG - University Of Maryland; He, Xiaohua; Wu, Xianli; Pehrsson, Pamela; Sun, Jianghao; XIE, ZHUOHONG - University Of Maryland; SLAVIN, MARGARET - University Of Maryland; YU, LIANGLI LUCY - University Of Maryland

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/21/2023
Publication Date: 4/6/2023
Citation: Gao, B., Zhu, L., Liu, Z., Li, Y., He, X., Wu, X., Pehrsson, P.R., Sun, J., Xie, Z., Slavin, M., Yu, L. 2023. Chemical composition of honeysuckle (Lonicerae japonicae) extracts and their potential in inhibiting the SARS-CoV-2 spike protein and ACE2 binding, suppressing ACE2, and scavenging radicals. Journal of Agricultural and Food Chemistry. 71(15):6133-6143. https://doi.org/10.1021/acs.jafc.3c00584.
DOI: https://doi.org/10.1021/acs.jafc.3c00584

Interpretive Summary: Honeysuckle has been used in functional tea products. The chemical compositions of the water and ethanol extracts of honeysuckle were examined in the present study, along with their potential in preventing and treating corona virus disease-2019 (COVID-19), including inhibiting SARS-CoV-2 spike protein angiotensin converting enzyme 2 (ACE2) binding, suppressing ACE2 activity and scavenging reactive free radicals. Thirty-six compounds were tentatively identified from the honeysuckle extracts, with ten of them reported for the first time. Both honeysuckle extracts dose-dependently inhibited the binding of SARS-CoV-2 spike protein to ACE2 and the ACE2 activity. At the same per botanical weight concentrations, the ethanol extract showed stronger effects in inhibiting SARS-CoV-2 spike protein binding to ACE2, and weaker effects on inhibiting ACE2 activity than the water extract. In addition, higher total phenolic contents and greater scavenging activities against free radicals were observed in the water extract than the ethanol extract. In conclusion, honeysuckle could potentially reduce the risk of SARS-CoV-2 infection.

Technical Abstract: Honeysuckle (Lonicerae japonicae) has been used in functional tea products. The chemical compositions of the water and ethanol extracts of honeysuckle were examined in the present study, along with their potential in inhibiting SARS-CoV-2 spike protein binding to ACE2, suppressing ACE2 activity and scavenging reactive free radicals. Thirty-six compounds were tentatively identified from the honeysuckle extracts using an HPLC-MS/MS method, with ten of them reported for the first time in honeysuckle. Both honeysuckle extracts dose-dependently inhibited the binding of SARS-CoV-2 spike protein to ACE2 and the ACE2 activity. The ethanol extract had a 100% inhibition on binding SARS-CoV-2 spike protein to ACE2 at 100 mg botanical equivalent/mL, whereas the water extract had a 65% binding inhibition at the same concentration. Furthermore, the water extract had a 90% ACE2 inhibition which was stronger than that of 62% with the ethanol extract on a per same botanical weight concentration basis. In addition, higher total phenolic contents and greater scavenging activities against hydroxyl (HO•), DPPH' and ABTS'+ radicals were observed in the water extract than the ethanol extract counterpart on a per dry botanical weight concentration basis. These findings suggest honeysuckle could potentially reduce the risk of SARS-CoV-2 infection and the development of severe COVID-19 symptoms.