Edible Bird’s Nest Potently Inhibits SARS-CoV-2 Infection: Evidence from an In Vitro Study

To date, no effective drug has been approved by regulatory authorities is established for SARS-CoV-2. Consequently, the exploration of natural products and phytopharmaceuticals with potential antiviral properties has become inevitable. This preliminary study investigates the bioactive compounds of acid extract from edible bird’s nest (EBN) and their antiviral activity against SARS-CoV-2. EBN samples obtained from East Kalimantan were extracted using an acid extraction method and subsequently lyophilized. Metabolomic profiling of the acid extract EBN was conducted using LC-HRMS. The in vitro cytotoxicity concentration (CC50) was determined using Vero-E6 cells. The antiviral activity of EBN was assessed using three treatment approaches: pre-treatment, co-treatment, and post-treatment, to determine the inhibitory concentration (IC₅₀). The selectivity index (SI) was calculated. Bioactive compounds such as N-acetylneuraminic acid, N-acetyl-D-glucosamine, ketodeoxynonulosonic acid, and N-acetyl-9- O-acetylneuraminic acid were presumed to possess antiviral activity. The in vitro results showed that the CC50 value of EBN on Vero-E6 cells was 10.28 mg/mL, while the IC₅₀ values were 0.021 ± 0.02 mg/mL (pre-treatment), 0.021 ± 0.01 mg/mL (co-treatment), and 0.505 ± 0.06 mg/mL (post-treatment). The corresponding selectivity index (SI) values were 496.70 ± 39.18, 489.07 ± 21.71, and 20.34 ± 0.26, respectively. In conclusion, the bioactive compounds possess potent antiviral activity against SARS-CoV-2. The interactions between EBN bioactive compounds and key viral proteins of SARS-CoV-2 may involve in the potential mechanism, thereby inhibiting the early stages of the viral replication cycle.