Recent advances on macroalgal pigments and their biological activities (2016-2021)

Macroalgal pigments can serve as indicators of an environmental stresses due to their higher accumulation during these conditions. Even though they exhibit protective role, a stress can cause their degradation. Many factors influence the pigment content in macroalgae including the temperature of seawater, salinity and acidification, but they are also dependent on macroalgal species. Brown macroalgae are known for their fucoxanthin content, red macroalgae are characterized by the presence of phycobiliproteins, while green macroalgae contain highest chlorophylls amount. This review reports the main pigments isolated from three different macroalgal groups including brown (Ochrophyta), red (Rhodophyta) and green (Chlorophyta) macroalgae along with their bioactivities for the period 2016-2021. The methods of their isolation and analysis are systematically represented with an emphasis on comparison between the conventional and innovative extraction methods. The pigments antioxidant, neuroprotective, cytotoxic, anticancer, anti-inflammatory, anti-hypertensive activities and others are summarized indicating the potential of targeted macroalgal species for being used as the sources of these bioactive compounds.