Fucoxanthin, A Carotenoid Derived from Phaeodactylum tricornutum Exerts Antiproliferative and Antioxidant Activities In Vitro

Abstract

Microalgae contain a multitude of nutrients and can be grown sustainably. Fucoxanthin, a carotenoid from Phaeodactylum tricornutum, could have beneficial health effects. Therefore, we investigated the anti-inflammatory, antioxidative and antiproliferative effects of fucoxanthin derived from this diatom in vitro. The effects of purified fucoxanthin on metabolic activity were assessed in blood mononuclear cells and different cell lines. In cell lines, caspase 3/7 activity was also analyzed. Nitrogen monoxide release and mRNA-expression of proinflammatory cytokines were measured. For antioxidant assays, cell free assays were conducted. Additionally, the antioxidant effect in neutrophils was quantified and glutathione was determined in HeLa cells. The results show that neither did fucoxanthin have anti-inflammatory properties nor did it exert cytotoxic effects on mononuclear cells. However, the metabolic activity of cell lines was decreased up to 58% and fucoxanthin increased the caspase 3/7 activity up to 4.6-fold. Additionally, dose-dependent antioxidant effects were detected, resulting in a 63% decrease in chemiluminescence in blood neutrophils and a 3.3-fold increase in the ratio of reduced to oxidized glutathione. Our studies show that fucoxanthin possesses antiproliferative and antioxidant activities in vitro. Hence, this carotenoid or the whole microalgae P. tricornutum could be considered as a food or nutraceutical in human nutrition, showcasing beneficial health effects.

Keywords: Phaeodactylum tricornutum; antioxidative; antiproliferative; fucoxanthin; microalgae.

Figure 1

Effects of fucoxanthin from P. tricornutum on GSH to GSSG ratio in HeLa cells (A) and on luminol chemiluminescence in freshly isolated PMLs (B) (n = 3–5). Different letters represent significantly different groups (ANOVA followed by Tukey post hoc test for GSH/GSSG assay or with Dunnett’s T3 post hoc test for luminol chemiluminescence, p < 0.05). Abbreviations: GSH glutathione, GSSG glutathione disulfide.

Figure 2

Effects of fucoxanthin from P. tricornutum on metabolic activity of HeLa (A), Caco-2 (B) and HepG2 (C) cells (n = 4–6). Cells were incubated for 48 hours, DMSO (5%) was used as a positive control. Caspase 3/7 activity as a marker for apoptosis was assessed in HeLa (D), Caco-2 (E) and HepG2 (F) cells (n = 4). Here, staurosporine (1 µM) was used as a positive control. Different letters mark significant differences (ANOVA followed by Tukey post hoc test for D or with Dunnett’s T3 post hoc test, p < 0.05).