Antimelanoma activity of Heterocapsa triquetra pigments

Abstract

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Carotenoids from Rhodomonas salina Induce Apoptosis and Sensitize A2058 Melanoma Cells to Chemotherapy

“…Pigments were extracted from the lyophilized biomass (2 g) in absolute ethanol (500 ml). The mixture was sonicated at 50 W-30 kHz (UP50H ultrasonicator, Hielscher Ultrasonics GmbH, Germany) for 30 min, on ice and under constant stirring (Haguet et al 2017). The extractive solution was filtered (PVDF 0.22-μm membrane) and the solvent was evaporated under vacuum, resulting in the R. salina extract (Rs-EtOH, 0.53 g).…”

“…To confirm cell rupture during sonication-assisted extraction, R. salina cells were freeze-dried before or after sonication, placed on a conductive double layer carbon support and examined by SEM using a Philips-FEI Quanta 200 ESEM/ FEG microscope (environmental mode) equipped with a FEG canon delivering 1 to 30 kV beam current (Haguet et al 2017).…”

“…Microalgae have hard cell wall in most of cases, which limits metabolites extraction by conventional methods. Accordingly, sonication-assisted extraction has been increasingly used to obtain compounds from different microalgae as previously demonstrated by our research group (Baudelet et al 2013;Juin et al 2015;Haguet et al 2017). To ensure complete extraction of pigments, R. salina freeze-dried biomass was sonicated for 30 min at 50 W-30 kHz, using ethanol as solvent.…”

“…Chlorophyll c 2 , chlorophyll a, and pheophytin a derivatives (hydroxyl, methoxylactone, and ethoxylactone forms) were also detected. Although these derivatives are naturally occurring in microalgae (Hynninen 1981;Baudelet et al 2013;Juin et al 2015;Haguet et al 2017), they may have originated during the extraction procedure due to the high chlorophyll instability. Chemical structures of the main identified molecules are presented in supplementary data.…”

“…Among these compounds, a range of bioactive carotenoids can be isolated, including β-carotene, fucoxanthin, zeaxanthin, lutein, violaxanthin, echinenone, and canthaxanthin, and some of them are produced exclusively by microalgae (Casagrande et al 2019). These pigments have often been associated with anticancer effects, including against cutaneous melanoma cell lines (Pasquet et al 2011;Baudelet et al 2013;Haguet et al 2017). They exert antiproliferative effect by inducing apoptosis and modulating signaling pathways involved in survival, cell proliferation, invasion, and metastasis.…”