Pigment Extracts of Tetradesmus obliquus, Phaeodactylum tricornutum and Desmodesmus armatus Exert Anti-Adipogenic Effects on Maturing 3T3-L1 Pre-Adipocytes

Microalgae have attracted the interest of researchers due to their high amounts of bioactive compounds with potential anti-obesity effects. In this context, the aim of this study is to analyse the effects of pigment extracts of <i>Tetradesmus obliquus</i>, <i>Phaeodactylum tricornutum</i> and <i>Desmodesmus armatus</i> on triglyceride accumulation in 3T3-L1 pre-adipocytes. Pigments were extracted and the chlorophyll and carotenoid profiles were analysed by HPLC-DAD-APCI-QTOF-MS analysis. Next, the three extracts were tested in maturing 3T3-L1 pre-adipocytes treated during 8 days at doses of 6.25, 12.5, 25 and 50 µg/mL. Cell viability was evaluated and triglyceride content of cells was measured by a commercial kit. Furthermore, adipogenic gene expression was measured in cells treated with the highest dose of the three extracts. The characterisation showed that the predominant pigments in each extract were different among the microalgae, with fucoxanthin being the main one in <i>Phaeodactylum tricornutum</i> and chlorophylls, lutein and violaxanthin/neoxanthin in the other two microalgae. All the tested microalgae extracts reduced triglyceride content of pre-adipocytes, although differing in the minimum effective dose. The underlying mechanism depends on the analysed extract, but the three extracts reduced adipogenesis via <i>Pparg</i> inhibition. In conclusion, the pigment extracts of the three microalgae exert anti-adipogenic effects in 3T3-L1 pre-adipocytes.