Chloroquine is an autophagy and toll-like receptors (TLRs) inhibitor. Chloroquine is an antimalarial and anti-inflammatory agent widely used to treat malaria and rheumatoid arthritis. Chloroquine is highly effective in the control of SARS-CoV-2 (COVID-19) infection in vitro with EC50 of 1.13 μM.
Chloroquine suppressed matrix metalloproteinase (MMP)-2 and MMP-9 mRNA expression and protein activity, whereas MMP-13 mRNA expression and proteolytic activity were increased.?Despite enhancing TLR9 mRNA expression, chloroquine suppressed TLR9 protein expression in vitro.
Daily treatment of mice with intraperitoneal (i.p.) chloroquine (80 mg/kg/day) for 22 days, did not inhibit the growth of control siRNA or TLR9 siRNA MDA-MB-231 breast cancer cells.