Ro 90-7501 is a bi-benzimidazole compound that was first found to retard the formation of mature amyloid β42 fibrils in a cell-based assay.[1] Instead, extended polymeric sheets and fibrillary intermediates of amyloid β42 accumulated in response to Ro 90-7501 treatment, resulting in reduced cytotoxicity (EC50 = 2 μM).1 More recently, Ro 90-7501 was shown to modulate signaling in cells stimulated with polyinosinic-polycytidylic acid (poly(I:C); a toll-like receptor 3 (TLR3), and RIG-1-like receptor agonist.[2] Ro 90-7501 (10 μM) enhanced poly(I:C)-induced IFN-β expression, decreased NF-κB activation, and amplified the suppression of vesiculastomatitis virus replication by poly(I:C) in HEK293 cells expressing TLR3.[2]

Reference
[1]. Bohrmann, B., Adrian, M., Dubochet, J., et al. Self-assembly ofβamyloid 42 is retarded by small molecular ligands at the stage of structural intermediates. Journal of Structural Biology 130(2-3), 232-246 (2000).
[2]. Guo, F., Mead, J., Aliya, N., et al. RO 90-7501 enhances TLR3 and RLR agonist induced antiviral response. PLoS One 7(10), (2012).