Antiviral effect of honey extract Camelyn against SARS-CoV-2

Abstract

This study aimed to evaluate the potential antiviral effects of honey extract “Camelyn” against Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2). The baby hamster kidney cell line 21 (BHK‐21), bone marrow-derived hematopoietic stem cells (HSCs), and splenic cells were used for Camelyn cytotoxicity assay. After the isolation procedures, cell viability was assessed by trypan blue dye exclusion under a microscope using a hemocytometer. The in vitro cell growth rate was carried out using the cell counting Kit 8 (CCK-8) assay. The cells were seeded in growth media with various Camelyn concentrations (35 μg, 50 μg, 70 μg, 100 μg, 150 μg, and 200 μg). The absorbance at 450 nm was determined by the multiplate reader. The antiviral effect was assessed by plaque reduction assay for the determination of drug susceptibility against SARS-CoV-2. Serial dilution of the selected compounds was pre-incubated with 40 to 100 plaque-forming units (PFUs) of SARS-CoV-2. The pre-incubated mix of Camelyn and SARS-CoV-2 was then added to the confluent Vero E6 cells after incubation cells were fixed and stained and the number of PFUs was counted under an inverted microscope and plotted against the logarithm of antiviral concentrations. Our study showed that Camelyn is not cytotoxic, has a stimulatory effect on cell proliferation, and has an inhibitory effect against SARS-CoV-2 with EC50 (half-maximal effective concentration) from 85.7 μg/mL to 192.4 μg/mL depending on product concentration and viral plaque per cell. © 2021 Global Research Online. All rights reserved.