Halamphora sp. reduces inflammation in LPS-stimulated human malignant melanoma and immortalized keratinocytes influencing TNF-α release

Abstract

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 Halamphora 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 a, a breakdown product of chlorophyll a. In order to investigate the mechanism of action, the TNF-alpha 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 & micro;g/mL of fraction D. This study reports for the first time the anti-melanoma and anti-inflammatory activities of Halamphora sp., identifying protein mediators and highlighting its biotechnological potential.