Exploring the Anti-Inflammatory Potential of Nannochloropsis sp. Extract

Microalgae have garnered increasing attention as promising sources of diverse natural anti-inflammatory compounds, including carotenoids, phenolics, and unsaturated fatty acids. In this study, we aimed to examine the anti-inflammatory properties of the methanol extract of Nannochloropsis sp. G1-5 (NG15), a strain of marine microalgae isolated from the southern West Sea of the Republic of Korea. Pigment and metabolite analyses revealed that the extract contained various carotenoids and polyunsaturated fatty acids alongside significant quantities of phenolic and flavonoid compounds, which are known to have anti-inflammatory activities. Cytotoxicity assays confirmed that the extract was non-toxic to RAW 264.7 macrophage cells at concentrations up to 1 mg/mL. Upon lipopolysaccharide (LPS) stimulation of the macrophage cells, the NG15 extract significantly inhibited nitric oxide (NO) production in a dose-dependent manner up to 81%. In addition, the NG15 extract reduced the expression of iNOS, COX-2, TNF-α, and IL-6 in the LPS-stimulated cells. These findings suggest that NG15 methanol extract exerts anti-inflammatory effects primarily through the suppression of NO generation without inducing cytotoxicity. Overall, these results underscore NG15 as a promising natural resource for the development of non-toxic and effective anti-inflammatory agents with potential applications in the biomedical and cosmeceutical industries.