Alzheimer's, Parkinson's, and
multiple sclerosis are
neurodegenerative diseases related by neuronal degeneration and death in specific areas of the central nervous system. These pathologies are associated with
neuroinflammation, which is involved in
disease progression, and halting this process represents a potential therapeutic strategy. Evidence suggests that microglia function is regulated by A1 and A2A
adenosine receptors (AR), which are considered as neuroprotective and neurodegenerative receptors, respectively. The manuscript's aim is to elucidate the role of these receptors in
neuroinflammation modulation through potent and selective A1AR agonists (N6-cyclopentyl-2'- or 3'-
deoxyadenosine substituted or unsubstituted in 2 position) and A2AAR antagonists (9-ethyl-
adenine substituted in 8 and/or in 2 position), synthesized in house, using N13 microglial cells. In addition, the combined
therapy of A1AR agonists and A2AAR antagonists to modulate
neuroinflammation was evaluated. Results showed that A1AR agonists were able, to varying degrees, to prevent the inflammatory effect induced by
cytokine cocktail (
tumor necrosis factor (TNF)-α,
interleukin (IL)-1β, and
interferon (IFN)-γ), while A2AAR antagonists showed a good ability to counteract
neuroinflammation. Moreover, the effect achieved by combining the two most effective compounds (1 and 6) in doses previously found to be non-effective was greater than the treatment effect of each of the two compounds used separately at maximal dose.