Garlic-Derived Allicin Modulates Expression of the SARS-CoV-2 Spike Receptor-Binding Domain in Human Splenic Fibroblasts

Allicin, a natural sulfur-rich compound, is formed when garlic is crushed or chopped. It has been used for centuries as a natural defence against bacteria and fungi. However, we do not fully understand how well it works against viruses, such as SARS-CoV-2. In this study, we investigated the effect of allicin on the expression of the SARS-CoV-2 receptor-binding domain of the spike protein in human primary splenic fibroblasts. These cells were transfected with a plasmid encoding RBD-S protein fused to a superfolder green fluorescent protein (sfGFP), a bright, stable marker. When cells were treated with 50μM allicin, either 30 min before or 6 h after transfection, a pronounced drop in fluorescence was observed, indicating reduced spike protein expression. Interestingly, the cell morphology, growth, and behavior remained normal, indicating that allicin could minimize spike protein levels without being toxic to the cells. These results open the door to the use of allicin as a gentle, natural antiviral agent and raise critical questions regarding the regulation of protein expression after transcription. Further research is required to understand these effects better.