Doxycycline has anti-viral effects. Doxycycline has been shown to have in vitro antiviral activity against several viruses, including SARS-CoV-2, vesicular stomatis virus, Chikungunya virus, Crimean-Congo hemorrhagic fever virus, and porcine reproductive and respiratory syndrome virus. In addition to its antiviral activity, doxycycline also has anti-inflammatory effects by decreasing the expression of various pro-inflammatory cytokines and chemokines. Doxycycline has been suggested as a potential partner of COVID-19 therapies due to its antiviral and anti-inflammatory effects[1][2][3][5].
Doxycycline inhibits the replication of these viruses by interacting with viral proteins or enzymes, such as NS2B-NS3 serine protease and Crimean-Congo hemorrhagic fever virus nucleoprotein. Doxycycline also inhibits the early-stage replication of the porcine reproductive and respiratory syndrome virus. In addition to its antiviral activity, doxycycline has anti-inflammatory effects by decreasing the expression of various pro-inflammatory cytokines.
Citations:
[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7663271/
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8464303/
[3] https://www.frontiersin.org/articles/10.3389/fmicb.2022.757418
[4] https://www.ijidonline.com/article/S1201-9712(22)00349-6/fulltext
[5] https://www.sciencedirect.com/science/article/pii/S2214250920301724
[6] https://pharmaceutical-journal.com/article/news/azithromycin-and-doxycycline-should-not-be-used-in-the-management-of-covid-19-dhsc-advises
