A new application of phycoerythrin and sulfated exopolysaccharides from Porphyridium cruentum: Effects on the regulation of lipid metabolism

Lipid-related disorders, including lipid accumulation into adipose tissue, obesity, insulin resistance, as well as fatty liver disease share oxidative stress as one of the key pathways involved. Antioxidant molecules obtained from natural sources can be used to encounter consumers' concerns about chemically synthesized ones. It is well established that microalgae are a reliable source of a wide variety of environmentally friendly and safe antioxidant molecules. In particular, Porphyridium cruentum has been studied as an abundant source of phycoerythrin and sulfated exopolysaccharides, both endowed with a potent antioxidant activity. Here, for the first time, phycoerythrin and sulfated exopolysaccharides were explored for their ability to interfere with 3T3-L1 adipocytes differentiation, affect de novo lipogenesis and enhance lipolysis in mature adipocytes, as well as to counteract lipid storage in AML12 hepatocytes, used as a hepatic steatosis model. The isolated antioxidant molecules affected pre-adipocytes differentiation inhibiting the master regulator of adipogenesis and genes involved in adipocyte maturation. In the hepatic steatosis model, sulfated exopolysaccharides were able to inhibit de novo lipogenesis whereas phycoerythrin showed a pro-fat effect. This study highlights that counteracting the oxidative stress is a necessary although not sufficient condition to counteract all lipid-related disorders.