Objective(s):Neuroinflammation and microglial activation are pathological features in central nervous system disorders. Excess levels of reactive oxygen species (ROS) and pro-inflammatory cytokines have been implicated in exacerbation of neuronal damage during chronic activation of microglial cells.Padina australis, a brown macroalga, has been demonstrated to have various pharmacological properties such as anti-neuroinflammatory activity. However, the underlying mechanism mediating the anti-neuroinflammatory potential ofP. australisremains poorly understood. We explored the use of MalaysianP. australisin attenuating lipopolysaccharide (LPS)-stimulated neuroinflammation in BV2 microglial cells.Materials and Methods:Fresh specimens ofP. australiswere freeze-dried and subjected to ethanol extraction. The ethanol extract (PAEE) was evaluated for its protective effects against 1 µg/ml LPS-stimulated neuroinflammation in BV2 microglial cells.Results:LPS reduced the viability of BV2 microglia cells and increased the levels of nitric oxide (NO), prostaglandin E2(PGE2), intracellular reactive oxygen species (ROS), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6). However, the neuroinflammatory response was reversed by 0.5–2.0 mg/ml PAEE in a dose-dependent manner. Analysis of liquid chromatography-mass spectrometry (LC-MS) of PAEE subfractions revealed five compounds; methyl α-eleostearate, ethyl α-eleostearate, niacinamide, stearamide, and linoleic acid.Conclusion:The protective effects of PAEE against LPS-stimulated neuroinflammation in BV2 microglial cells were found to be mediated by the suppression of excess levels of intracellular ROS and pro-inflammatory mediators and cytokines, denoting the protective role ofP. australisin combating continuous neuroinflammation. Our findings support the use ofP. australisas a possible therapeutic for neuroinflammatory and neurodegenerative diseases.