Hydroxybenzoic acid esters as dual antioxidant and anti-neuroinflammatory agents: in silico and in vitro evaluation

Neuroinflammation, primarily mediated by activated microglia, plays a central role in the onset and progression of neurodegenerative diseases. In search of effective modulators of these processes, we investigated the antioxidant and anti-neuroinflammatory potential of hydroxybenzoic acid esters. A library of 42 esters and their three parent acids was evaluated through molecular docking against proteins of the lipopolysaccharide (LPS) signaling pathway, including LPS-binding protein (LBP), CD14, and TLR4/MD2. The best-scoring compounds were synthesized and subjected to in vitro validation. Several derivatives, particularly isopentyl, octyl, and benzyl esters of 2-, 2,4-, and 3,4,5-hydroxybenzoic acids, demonstrated favorable docking interactions and were further examined. Antioxidant assays (ABTS and DPPH) revealed radical scavenging activities comparable to vitamin C, with 3,4,5-hydroxybenzoic derivatives exhibiting the highest efficacy. In BV2 microglial cells, selected esters reduced reactive oxygen species (ROS) and nitric oxide (NO) production following stimulation with hydrogen peroxide or LPS, thereby restoring cellular metabolic activity. Furthermore, supernatants from ester-treated microglia attenuated neurotoxicity in SH-SY5Y cells, confirming their neuroprotective effects. Importantly, these compounds displayed no cytotoxicity toward fibroblasts or microglia at tested concentrations, supporting their biocompatibility. Taken together, this study highlights hydroxybenzoic acid esters as promising multifunctional agents with dual antioxidant and anti-neuroinflammatory properties. Their ability to modulate microglial activation and protect SH-SY5Y cells suggests potential therapeutic relevance in managing neurodegeneration. Future work will focus on in vivo validation and preclinical development to advance these compounds toward medicinal applications.