Chloroquine is a Toll-like receptor inhibitor that inhibits autophagy. Chloroquine has anti-malarial and anti-inflammatory activity and is widely used in the treatment of malaria and rheumatoid arthritis. Chloroquine also has anti-SARS-CoV-2 (COVID-19) activity and anti-HIV-1 activity.

METHODS: Human cholangiocarcinoma cells QBC939 were treated with Chloroquine (1.2-200 µM) for 24 h. Cell growth inhibition was detected by MTT.
RESULTS: Chloroquine dose-dependently inhibited the cell growth of HRECs with an IC50 of 53.01 µM. [1]
METHODS: Human non-small cell lung cancer cells A549 were treated with Chloroquine (10-80 μM) for 24 h. The expression levels of target proteins were detected by Western Blot.
RESULTS: Chloroquine induced an increase in LC3-II expression and a decrease in LC3-I expression, resulting in an increase in the LC3-II/LC3-I ratio. The highest LC3-II/LC3-I ratio was observed with 40 μM Chloroquine treatment. [2]
METHODS: Human osteosarcoma cells U2OS and human cervical cancer cells HeLa were treated with Chloroquine (100 μM) for 5 h. LAMP1, a marker protein for late endosomal compartment and lysosome, was detected by Immunofluorescence.
RESULTS: Chloroquine increased the area of LAMP1 positive structures. [3]

METHODS: To investigate the effects of Chloroquine on acute liver injury and its potential molecular mechanisms, a single dose of Chloroquine (5-50 mg/kg) was administered intraperitoneally to C57BL/6 mice 2-24 h before CCl4 (10 mL/kg) injection.
RESULTS: Chloroquine pretreatment significantly inhibited CCl4-induced acute liver injury, as evidenced by a decrease in serum aminotransferases, aspartate aminotransferase, and a decrease in the histological score of liver injury, and down-regulated CCl4-induced high-mobility histone 1 (HMGB1) expression in liver tissues as well as the levels of serum HMGB1, IL-6, and TNF-α. levels. [4]
METHODS: To investigate the relationship between Chloroquine and retinopathy, Chloroquine (50 mg/kg ) was administered intraperitoneally to C57/BL6 mice three times a week for six weeks.
RESULTS: Chronic administration of Chloroquine induced retinopathy in mice. mRNAs for IL-1β mRNA, a component of inflammatory vesicles, and caspase1 were increased in the retinas of Chloroquine-treated mice, consistent with the initiation of inflammatory vesicles, and NTPDase1 was increased, suggesting an increase in extracellular ATP in the retina. [5]