Assessment of cytotoxicity and antiviral activity against SARS-CoV-2 of the mixture of lactoferrin, artemisinin, and azithromycin in vitro

Ryabchenkova AA1, Kopat VV1, Chirak ER1, Chirak EL1, Leneva IA2, Glubokova EA2, Kartashova NP2, Kolmakov NN3, Dukhovlinov IV1
About authors

1 ATG Service Gen LLC, St. Petersburg, Russia

2 Mechnikov Research Institute of Vaccines and Sera, Moscow, Russia

3 Institute of Experimental Medicine, St Petersburg, Russia

Correspondence should be addressed: Anastasia A. Ryabchenkova
Prospect Maly V.O., 57, k. 4, litera Zh, k. 5-Н, St. Petersburg, 199178, Russia; ur.eneg-ecivres@avoknehcbair

About paper

Acknowledgements: we would like to express our gratitude to Evgeny B. Faizuloev (Mechnikov Research Institute of Vaccines and Sera) for the provided virus. The study was performed using the equipment provided by the Center for Collective Use of the Mechnikov Research Institute of Vaccines and Sera.

Author contribution: Ryabchenkova AA — study concept and design, data analysis and interpretation, manuscript writing; Kopat VV — concept, design, and organization of research, manuscript writing; Chirak ER, Chirak EL — study design, preparation of samples and materials; Leneva IA — experimental procedures, data acquisition, analysis, and interpretation; Kartashova NP, Glubokova EA — experimental procedures; Kolmakov NN — study concept, manuscript editing; Dukhovlinov IV — initiation, project management, developing the concept of drug composition, organization of research funding.

Compliance with ethical standards: the study was performed in accordance with the principles of the World Medical Association Declaration of Helsinki.

Received: 2022-09-23 Accepted: 2022-11-14 Published online: 2022-12-25

Lactoferrin, artemisinin, and azithromycin exhibit a broad spectrum of antiviral, immunomodulatory, and anti-inflammatory effects. The experiments show that these drugs partially inhibit the infection caused by SARS-CoV-2 in vitro. This allows us to conclude that the effects on the entry of virions into cells mediated by each of these substances taken separately are insufficient for complete inhibition of the SARS-CoV-2 infection. The study was aimed to perform in vitro assessment of cytotoxicity and antiviral activity against the laboratory SARS-CoV-2 strain of the mixture of active ingredients: lactoferrin, artemisinin, and azithromycin. We used the Vero CCL81 (ATСС) cell line and the Dubrovka laboratory strain of SARS-CoV-2 (GenBank ID: MW161041.1), isolated in the Vero CCL81 cell culture from the nasopharyngeal swab of patient with СOVID-19. Cytotoxic effects and antiviral activity against SARS-CoV-2 of the drug mixture were assessed based on the cytopathic effects using the MTT (methylthiazolyldiphenyl-tetrazolium bromide) assay. Hydroxychloroquine was used as a reference drug. It has been shown that at high  (MOI 100) and low (MOI 20) multiplicity of infection used in the Vero CCL 81 cell culture, the mixture of artemisinin, lactoferrin and azithromycin has a significant effect on the SARS-CoV-2 reproduction, and IC50 (half maximal inhibitory concentration) is estimated as the 1 : 2 dilution in both cases. The findings make it possible to conclude that the studied mixture is low toxic and shows significant antiviral effects in vitro.

Keywords: cytotoxicity, COVID-19, SARS-CoV-2, antiviral activity, artemisinin, azithromycin, lactoferrin, drug repurposing