Design, Synthesis, and Anti-Neuroinflammatory Activity of Amide- Containing Dithiolethiones

Background: Multiple sclerosis (MS) is a chronic immune-mediated disease of the central nervous system characterized by demyelination of neurons and neurodegeneration. Current MS therapies ameliorate inflammatory damage but are unable to address the degenerative aspects of the disease. Objective: In this report, we evaluate the ability of amide-based dithiolethiones (DTTs) to suppress neuroinflammation in microglia and increase anti-oxidant capacity in neuron-like cells. Methods: A series of amide-containing DTTs were designed, synthesized, and assayed for the ability to suppress pro-neuroinflammatory cytokines IL-12p40 and IL-23p19 induced by LPS in the BV2 microglial cell line. Lead analog 2c was identified and further characterized. Results: Structure-activity data revealed tolerance towards a variety of amides. Morpholine analog 2c dose-dependently reduced various other inflammatory cytokines and mediators, including TNF, IL-6, IL-1β, NOS2, and COX2. Additionally, 2c elevated cellular levels of glutathione in SH-SH5Y neuronal cell line. Furthermore, mechanistic studies showed that 2c increased the expression of antiinflammatory Nrf2 and HMOX proteins. Conclusion: The combination of anti-neuroinflammatory and anti-oxidant activities of amide-based DTTs suggests that they are promising agents for the treatment of both demyelination and neurodegeneration in MS.