Resiquimod (R848) is a Toll-like receptor 7/8 (TLR7/TLR8) agonist that induces cytokine upregulation. Resiquimod is an immunomodulator with antitumor and antiviral activity.

Imiquimod (R 837) is an immune response modifier that acts as a toll-like receptor 7 agonist.

CU-115 is a selective and potent TLR8 antagonist with IC50 of 1.04 µM and =>50 µM for TLR8 and TLR7, respectively. CU-115 decreases production of TNF-α and IL-1β activated by R-848 in THP-1 cells.

TLR3-IN-1 (CU CPT 4a) is a selective TLR3 inhibitor (IC50: 3.44 μM in RAW 264.7 cells). It can inhibit TLR3/dsRNA complex-mediated downstream signaling pathways and inhibit the production of TNF-α and IL-1β in whole cells.

Hydroxychloroquine sulfate (Acidum iopanoicum) inhibits plasmodial heme polymerase. It is a chemotherapeutic agent that acts against erythrocytic forms of malarial parasites. Hydroxychloroquine appears to concentrate in food vacuoles of affected protozoa.

Polyinosinic-polycytidylic acid sodium (Poly(I:C) sodium) is a synthetic analog of double-stranded RNA and an agonist of toll-like receptor 3 (TLR3) and retinoic acid inducible gene I (RIG-I)-like receptors (RIG-I and MDA5).

CU-CPD107 is a selective agonist of toll-like receptor 8 (TLR8) and also shows activation activity against ssRNA ligands. CU-CPD107 acts as an inhibitor of TLR8 signaling in the presence of R848 (IC50=13.7 μM). CU-CPD107 exhibited coagonist activity in the presence of ssRNA, while CU-CPD107 alone could not affect TLR8 signal transduction.

Imiquimod hydrochloride (R 837 hydrochloride), a selective toll-like receptor 7 (TLR7) agonist, functions as an immune response modifier with in vivo antiviral and antitumor properties, and is utilized in researching external genital and perianal warts, cancer, and COVID-19 [1] [2].