In vitro antiviral effect of Mexican and Brazilian propolis and phenolic compounds against human coronavirus 229E

ABSTRACT

Propolis is a resinous substance collected by bees (Apis mellifera). It is used for its biological properties. This natural product is available as a safe therapeutic option. Herein, we report the antiviral effects of brown propolis extract from Mexico and green and red propolis extracts from Brazil, as well as their phenolic compounds (quercetin, caffeic acid, and rutin) in preventing infection of MRC-5 cells by HCoV-229E. Normal human fibroblast lung cells (MRC-5) were used to determine the cytotoxicity of the compounds. All samples studied showed antiviral activity. Green and brown propolis extracts, and quercetin exhibited the best EC₅₀ values with values of 19.080, 11.240, and 77.208 µg/mL against HCoV-229E, respectively, and with TC₅₀ of 62.19, 29.192, and 298 µg/mL on MRC-5 cells, respectively. These results are the first in vitro study of the effects of propolis on HCoV-229E and provide the basis for the development of natural formulations against other coronavirus strains.

KEYWORDS:

• coronavirus
• propolis
• quercetin
• rutin
• caffeic acid

Acknowledgements

The authors wish to thank Priscilla Valenzuela and Andrew Rabe for providing technical support, and Martín Guadalupe Rodríguez of Cooperativa mieles de Cajeme for the donations of propolis samples in Mexico, and Collectors from Brazil-MN Propolis-Insdústria Comércio e Exportação Ltda. MAU-G is a Technological Development fellow from CNPq (Proc. 304747/2020-3).

Author Contributions

N.P.S-B, C.P.G.: investigation and supervision conceptualization, methodology, writing – review and editing. A.P.B-C, M.A.U-G: review and editing. N.P.S-B, C.P.G.: project administration, original draft preparation, and resources. L.I.: investigation and supervision, review and editing. J.C.G-R: review and editing, visualization, and resources. All authors have read and agreed to the published version of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

Department of Environmental Science. University of Arizona. Water & Energy Sustainable Technology (WEST) Center, Consejo Nacional de Ciencia y Tecnología (CONACyT), and University of Sonora project under Grant (USO313007158). [USO313007158]