The phytochemical characteristics of <i>Swertia mussotii</i> Franch. and the potential for treating neuroinflammation <i>in vitro</i> through the NF-κB pathway

Microglial activation is a key driver of neuroinflammation, rendering it a critical therapeutic target. This study explored the neuroprotective potential of compounds derived from <i>Swertia mussotii</i> Franch. against lipopolysaccharide (LPS)-induced microglial activation. Eleven compounds were isolated from this plant. Screening using an LPS-stimulated BV2 microglial cell model identified amarogentin (AMG) as exhibiting significant protective effects. Subsequent mechanistic investigations revealed that AMG effectively mitigated LPS-induced morphological changes associated with microglial activation and suppressed the release of nitric oxide (NO) (<i>p</i> < 0.01) and pro-inflammatory cytokines (TNF-α, IL-1β) (<i>p</i> < 0.05). Moreover, AMG markedly downregulated the mRNA expression of inducible nitric oxide synthase (iNOS) (<i>p</i> < 0.01), TNF-α (<i>p</i> < 0.01), and IL-1β (<i>p</i> < 0.05). At the protein level, AMG inhibited the expression of phosphorylated p65 (p-p65) (<i>p</i> < 0.01). These results indicate that AMG confers robust neuroprotective effects against microglial activation-induced injury, likely <i>via</i> suppression of the NF-κB signalling pathway.