Halamphora sp. Reduces Inflammation in LPS-Stimulated Human Malignant Melanoma and Immortalized Keratinocytes Influencing TNF-α Release

Malignant melanoma is skin cancer arising from genetically altered melanocytes. Recently, a complex relationship between melanoma and chronic inflammation has been highlighted, representing an excellent condition for tumor development. Microalgae have been shown to be a promising source of bioactive compounds for drug discovery. In this study, we investigated <i>Halamphora</i> sp. (BEA0050) to identify possible compounds with immunomodulatory activity. The most active fraction (fraction D) showed anti-inflammatory activity against human melanoma cancer cells (A2058) stimulated using lipopolysaccharide (LPS) to induce an inflammatory phenotype. Chemical profiling of the bioactive fraction using chromatography and high-resolution mass spectrometry (UHPLC-HR-MS) revealed hydroxypheophorbide <i>a</i>, a breakdown product of chlorophyll a. In order to investigate the mechanism of action, the TNF-<i>α</i> release was detected through ELISA sandwich assays in A2058 cells and through confocal microscopy in LPS-stimulated HaCaT cells. Gene expression of principal pro-inflammatory cytokines and pathways was detected through real-time PCR, which showed the down-regulation of the inflammatory pathway in LPS-induced A2058 and HaCaT cells treated with 12.5 µg/mL of fraction D. This study reports for the first time the anti-melanoma and anti-inflammatory activities of <i>Halamphora</i> sp., identifying protein mediators and highlighting its biotechnological potential.