Anti-inflammatory activity of dried laver ( Porphyra spp.) extracts: A comparative analysis of varieties and extraction methods on the NF-κB pathway

This study evaluated the functional value of dried laver in high value-added applications. To this end, we explored the anti-inflammatory properties of two types of dried laver, Porphyra yezoensis (P-yezo) and Porphyra dentata (P-dent), by analyzing hot water extracts (WP-yezo, WP-dent) and subcritical water extracts (SP-yezo, SP-dent) of RAW 264.7 cells. Compared with hot water extracts (WP-yezo, WP-dent), subcritical water extracts (SP-yezo, SP-dent) markedly inhibited the levels of nitric oxide (NO) and reactive oxygen species (ROS) in a concentration-dependent manner. SP extract treatment at 200 μg/mL significantly attenuated interleukin-6 (IL-6) levels, indicating stronger anti-inflammatory potential than their hot water counterparts. In particular, SP-dent inhibited NF-κB-related gene and protein levels as well as ERK1/2 phosphorylation. These findings indicate that subcritical water extracts of dried laver, especially SP-dent, showed pronounced anti-inflammatory effects through the regulation of NF-κB and ERK1/2 signaling in activated macrophages.