Moss Extracts as Natural Neuroprotective Agents: Mitigating LPS-Induced Neuroinflammation and Microglial Activation

Neuroinflammation plays a central role in the pathogenesis of neurodegenerative diseases, and there is increasing interest in identifying natural compounds with anti-neuroinflammatory and neuroprotective effects. In this study, we aimed to investigate the biological activities of ethanol and ethyl acetate extracts from five moss species (Dicranum scoparium, Fontinalis antipyretica, Hypnum cupressiforme, Polytrichum formosum, and Tortella tortuosa) with a focus on their neuroprotective and anti-neuroinflammatory potential. Phytochemical profiling revealed the presence of phenols (up to 24.77 mg GAE/g), phenolic acids (up to 235.48 mg CAE/g), and triterpenoids (up to 367.98 mg UAE/g). A series of in vitro assays, including acetylcholinesterase (AChE) and tyrosinase inhibition, MTT, NBT, Griess, and ELISA, were used to assess their bioactivity. Several extracts, particularly ethanolic, significantly inhibited AChE activity, while tyrosinase inhibition was moderate and concentration-dependent. Most extracts maintained >85% cell metabolic activity in BV2 mouse microglia and L929 mouse fibroblasts. Moss extracts significantly suppressed lipopolysaccharide (LPS)-induced production of reactive oxygen species (ROS), nitric oxide (NO), interleukin 6 (IL-6), and tumor necrosis factor alpha (TNF-α) in BV2 cells and reduced microglia-mediated neurotoxicity in undifferentiated SH-SY5Y cells. These findings indicate that moss-derived extracts possess promising anti-neuroinflammatory and neuroprotective properties that warrant further investigation.