Chloroquine phosphate

Chloroquine phosphate (Aralen phosphate) is an antimalarial and anti-inflammatory agent widely used for malaria and rheumatoid arthritis. Chloroquine phosphate acts as an inhibitor of autophagy and toll-like receptors, effectively suppressing SARS-CoV-2 (COVID-19) infection (EC50 = 1.13 μM). Chloroquine phosphate can be utilized in research on autophagy, lysosomal function, and tumor diseases.

Cytotoxicity against human K562 cells:31.83 nM, Cytotoxicity against hμMan KB cells by microplate method:0.6 μM

Methods: Vero E6 cells + SARS-CoV Frankfurt 1 strain (infectious dose: 100 CCID₅₀) were used. Chloroquine phosphate (1–100 μM) was added simultaneously with the virus and incubated for 3 days. Cell viability was assessed using the MTS assay.
Results: Chloroquine phosphate demonstrated efficacy at low micromolar concentrations and exhibited a broad therapeutic window. [1]
Methods: Add ATRA (1 mM) and Chloroquine phosphate (10 μM) to human/mouse cancer-associated fibroblast (CAF) cell lines. Detect autophagy markers via immunofluorescence and Western blot.
Results: Chloroquine phosphate treatment inhibits CAF activation. [2]

Methods: Mice implanted with KPC cells in situ received intraperitoneal injections of free chloroquine phosphate (70 mg/kg, once daily), intravenous injections of free chloroquine phosphate (70 mg/kg, once daily), or intravenous injections of CQ-MSC-Lipo (80 μg/mouse, every 3 days). All groups received intraperitoneal injections of anti-PD-1 (200 μg) intraperitoneally.
Results: Chloroquine phosphate-MSC-Lipo combined with anti-PD-1 demonstrated superior efficacy compared to free chloroquine phosphate combination therapy, significantly inhibiting tumor growth.[2]

The cells are cultured in 6-well plates with normal culture medium in the presence of vehicle or 25 or 50 μM chloroquine, until near confluency, after which they are rinsed with sterile phosphate-buffered saline (PBS) and cultured further for the indicated times in serum-free culture medium. At the desired time-points, the culture medium is discarded and the cells are quickly harvested in lysis buffer and clarified by centrifugation. Subsequent to boiling the supernatants in reducing sodium dodecyl sulfate (SDS) sample buffer, equal amounts of protein (100 μg) are loaded per lane and the samples are electrophoresed into 10 or 4-20% gradient polyacrylamide SDS gels, then transferred to a nitrocellulose membrane. To detect TLR9, the blots were incubated overnight at 4°C with anti-TLR9 antibodies, diluted 1:500 in Tris-buffered saline with 0.1% (v/v) Tween-20 (TBST). Equal loading is confirmed with polyclonal rabbit anti-actin. Secondary detection is performed with horseradish peroxidase-linked secondary antibodies. The protein bands are visualized by chemiluminescence using an ECL kit [2].

Control and TLR9 siRNA MDA-MB-231 cells (5×105 cells in 100 μL) are inoculated into the mammary fat pads of four-week-old, immune-deficient mice (athymic nude/nu Foxn1). Treatments are started seven days after tumor cell inoculation. The mice are treated daily either with intraperitoneal (i.p.) chloroquine (80 mg/kg) or vehicle (PBS). The animals are monitored daily for clinical signs. Tumor measurements are performed twice a week and tumor volume is calculated according to the formula V=(π/6) (d1×d2)3/2, where d1 and d2 are perpendicular tumor diameters. The tumors are allowed to grow for 22 days, at which point the mice are sacrificed and the tumors are dissected for a final measurement. Throughout the experiments, the animals are maintained under controlled pathogen-free environmental conditions (20-21°C, 30-60% relative humidity and a 12-h lighting cycle). The mice are fed with small-animal food pellets and supplied with sterile water ad libitum [2].

DMSO: Insoluble

H2O: 65.625 mg/mL (127.21 mM), Sonication is recommended.