Chemical Composition, Antioxidant, and Anti-Inflammatory Properties of the Extracts of Hormophysa triquetra and Padina gymnospora

Introduction: Hormophysa triquetra and Padina gymnospora are widely distributed seaweeds in subtropical and tropical seas; however, there are limited or no reports on their biomedical applications. The aim of this study was to investigate the chemical composition of these species and present their antioxidant and anti-inflammatory properties. Methods: The total phenolic content in an 80% methanol extract of the species was measured. High-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS) were used to assess the components of the extracts. Antioxidant activity against AAPH- or H₂O₂-induced oxidative stress in Vero cells was measured using the MTT assay. For anti-inflammatory assessment, the Griess assay was used to measure nitric oxide (NO) production in LPS-stimulated RAW264.7 cells, and enzyme linked immunosorbent assay was employed to measure the inhibition of cytokine production in LPS-stimulated bone marrow-derived dendritic cells. Results: Both seaweed species exhibited significant phenolic content. HPLC profiles revealed 19 compounds, with cinnamic acid (29.63 µg/g) and pyrogallol (25.33 µg/g) dominating in Hormophysa triquetra and Padina gymnospora, respectively. GC-MS profiles were dominant for fatty acids and their derivatives, along with diterpenes. The extracts exhibited protective effects against oxidative stress. Furthermore, the extracts inhibited the production of NO and cytokines in a dose-dependent manner. Conclusion: These findings highlight the therapeutic potential of the species against oxidative stress and inflammation, suggesting their applicability in the pharmaceutical and nutraceutical industries.