Design of dual inhibitors of ROCK-I and NOX2 as potential leads for the treatment of neuroinflammation associated with various neurological diseases including autism spectrum disorder

Abstract

Inhibition of both Rho kinase (ROCK-I) and NADPH oxidase (NOX2) to treat neuroinflammation could be very effective in the treatment of progressive neurological diseases like Alzheimer's disease, autism spectral disorder, and fragile X syndrome. NOX2 being a multi-enzyme component is activated during host defense in phagocytes such as microglia, to catalyze the production of superoxide from oxygen, while ROCK is an important mediator of fundamental cell processes like adhesion, proliferation and migration. Phosphorylated ROCK was found to activate NOX2 assembly via Ras related C3 botulinum toxin substrate (Rac) in disease conditions. Overexpression of ROCK-I and NOX2 in innate immune cells like microglial cells contribute to progressive neuronal damage early in neurological disease development. In the present study we employed a computer-aided methodology combining pharmacophores and molecular docking to identify new chemical entities that could inhibit ROCK-I as well as NOX2 (p47 phox). Among the huge dataset of a commercial database, top 18 molecules with crucial binding interactions were selected for biological evaluation. Seven among the lead molecules exhibited inhibitory potential against ROCK-I and NOX2 with IC₅₀s ranging from 1.588 to 856.2 nM and 0.8942 to 10.24 μM, respectively, and emerged as potential hits as dual inhibitors with adequate selectivity index (SI = CC₅₀/GIC₅₀) in cell-based assays. The most active compound 3 was further found to show reduction of the pro-inflammatory mediators such as TNFα, interleukin-6 (IL-6) and interleukin-1beta (IL-1β) mRNA expression levels in activated (MeHg treated) human neuroblastoma (IMR32) cell lines. Hence the present work documented the utility of these dual inhibitors as prototypical leads to be useful for the treatment of neurological disorders including autism spectrum disorder and Alzheimer's disease.