Design, synthesis and bioactivity study of N-salicyloyl tryptamine derivatives as multifunctional agents for the treatment of neuroinflammation.

Because of the complex etiology in neuroinflammatory process, the design of multifunctional agents is a potent strategy to cure neuroinflammatory diseases including AD and PD. Herein, based on the combination principles, 23 of N-salicyloyl tryptamine derivatives as multifunctional agents were designed and their new application for anti-neuroinflammation was disclosed. In cyclooxygenase assay, two compounds 3 and 16 displayed extremely preferable COX-2 inhibition than N-salicyloyl tryptamine. In LPS-induced C6 and BV2 cell models, some compounds decreased the production of proinflammatory mediators NO, PGE2, TNF-α, iNOS, COX-2 and ROS, while increased the production of IL-10. Among them, compound 3 and 16 showed approximately six-fold better inhibition on nitric oxide production than N-salicyloyl tryptamine in C6. Besides, compounds 3, 13 and 16 attenuated the activation of BV2 and C6 cells. More importantly, in vivo, compounds 3 and 16 reduced GFAP and Iba-1 levels in the hippocampus, and displayed neuroprotection in Nissl staining. Besides, both compounds 3 and 16 had high safety (LD50 > 1000 mg/kg). Longer plasma half-life of compounds 3 and 16 than melatonin supported combination strategy. All these results demonstrated that N-salicyloyl tryptamine derivatives are potential anti-neuroinflammation agents for the treatment of neurodegenerative disorder.