Cao et al.
Minocycline inhibits tick-borne encephalitis virus and protects infected cells via multiple pathways. Viruses. 2024;16(7):1055. doi:10.3390/v16071055
Currently, no specific antiviral drug has been approved for treating TBE (tick-borne encephalitis) patients. Several studies have shown that tetracycline antibiotics, including minocycline, possess properties beyond their antimicrobial activity. Minocycline is commonly used to treat bacterial infections if sensitive to tetracycline antibiotics; and areas of application are skin infections like gram-positive bacteria, acne, rosacea, borreliosis, and intracellular pathogens. Recent research suggests that minocycline may also be effective against certain orthoflaviviruses. A study was conducted to evaluate whether minocycline affects the replication of the TBE virus.
The survival rate of Vero cells treated with minocycline decreased with increasing concentrations of minocycline, with no cytotoxicity observed at concentrations below 20 mM. Minocycline at concentrations of 5, 10, and 20 mM inhibited TBE virus replication in a dose-dependent manner. Post-treatment with minocycline for 48h inhibited the expression of TBE virus RNA and proteins and reduced the progeny of virus. Transcriptome analyses indicated that the inhibition of TBE virus replication by minocycline might be related to the regulation of the calcium-signaling pathway and the Ras-Raf-MEK-ERK (MAPK/ERK) pathway. Additionally, minocycline suppressed the expression of the inflammatory factor IL-6.
As there is still no established treatment regimen for TBE patients, the development of anti-TBE virus compounds is crucial to expedite drug development. This study demonstrated the in-vitro inhibitory effects of minocycline and provided initial insights into its mechanism of action.