Ginseng is a well-established functional food for brain health. However, its active ingredients have not yet been identified. Gintonin is a promising compound isolated from white/red ginseng. Its lysophosphatidic acid (LPA) is an exogenous G protein-coupled LPA receptor (LPAR) agonist. Korean red ginseng marc (KRGM) is a by-product after KRG extractions. In a previous study, we demonstrated that KRGM-derived gintonin (KRGM-G) contains LPA C[Formula: see text], a major functional component of both white and red ginseng. [Formula: see text] transgenic mice and SH-SY5Y cells were used to determine molecular mechanisms involved in KRGM-G-mediated anti-Alzheimer's disease (AD) effects. KRGM-G improved cognition impairment associated with alleviation of amyloid-β accumulation in the brain (hippocampus and cortex) in [Formula: see text] mice. KRGM-G inhibited activation of inflammatory cells (Iba-1-positive microglia and GFAP-positive astrocyte) and expression of pro-inflammatory mediators (IL-1β, IL-6, iNOS, or NO) in the brains of [Formula: see text] mice, increased the viability of H