Inflammation inside the brain and nervous system—a common driver of neurodegenerative diseases from Alzheimer’s to Parkinson’s.Neuroinflammation involves activation of microglia and astrocytes within the central nervous system, producing pro-inflammatory cytokines (TNF-α, IL-1β, IL-6), reactive oxygen species, and complement factors. Chronic neuroinflammation contributes to neurodegeneration in Alzheimer’s disease, Parkinson’s disease, and multiple sclerosis. Several peptides demonstrate anti-neuroinflammatory properties: cortistatin (suppresses microglial activation), PACAP (neuroprotective via PAC1), orexin (modulates neuroinflammatory cascades), and galanin (regulates hippocampal inflammation).