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.

Microalgae are rich in macronutrients and therefore, they have been proposed as a potential future food source preserving natural resources. Here, we studied safety and bioavailability of algae nutrients in mice. Three microalgae species, Chlorella vulgaris, Nannochloropsis oceanica and Phaeodactylum tricornutum, were studied after ball mill disruption at different doses (5%, 15% and 25% dry weight) for 14 days. In response to all three algae diets, we observed a weight gain similar or superior to that in response to the control diet. No substantial differences in organ weights nor gut length occurred. Protein bioavailability from the algae diets did not differ from the control diet ranging from 58% to 77% apparent biological value. Fat absorption was lower for microalgae compared to soy oil in control diets, albeit still substantial. High liver eicosapentaenoic acid levels were measured following feeding with N. oceanica, the algae richest in omega-3 fatty acids. Neither histological nor serum analyses revealed any heart, kidney or liver toxicity induced by any of the algae diets. Algae-rich diets were thus well accepted, well tolerated and suitable for the maintenance of body weight and normal organ function. No toxicological effects were observed.

Unter Mikroalgen fasst man mikroskopisch kleine, Fotosynthese betreibende Organismen zusammen, die in aquatischen Umgebungen vorkommen. Sie enthalten eine Vielzahl von Nährstoffen, darunter auch Proteine, Kohlenhydrate, Carotinoide, Vitamine, Mineralstoffe und Fettsäuren. In Lebensmitteln verarbeitet findet man heutzutage vor allem die Grünalge Chlorella und das Cyanobakterium Arthrospira. Die steigende Weltbevölkerung bei gleichzeitig begrenztem Ackerland wird in den nächsten Jahren zu einer noch stärkeren Nahrungsmittelknappheit führen. Aus diesem Grund sind Mikroalgen in den vergangenen Jahren in den Fokus der Wissenschaft gerückt. Neben einem guten Nährstoffprofil sind sie nämlich nicht auf landwirtschaftliche Nutzflächen angewiesen, sondern können in Ponds oder Fotobioreaktoren gezüchtet werden. Allerdings sind Mikroalgen bisher noch wenig in der menschlichen Ernährung verbreitet. Dies könnte zum einen daran liegen, dass bislang nur wenige der über 200 000 Arten für den menschlichen Konsum zugelassen sind. Des Weiteren spielen vor allem die Geschmacksveränderungen, die mit einem erhöhten Mikroalgenanteil einhergehen, und die hohen Produktionskosten eine große Rolle. Nichtsdestotrotz weisen Mikroalgen eine Vielzahl von bioaktiven Komponenten auf, die potenzielle gesundheitliche Vorteile besitzen. Neben immunmodulatorischen und antioxidativen Effekten weisen sie präbiotische, antivirale und entgiftende Wirkungen auf. Außerdem sind Mikroalgen eine vegane Quelle für Omega-3-Fettsäuren, was zum Schutz der Ressource Fisch beitragen könnte. Mikroalgen besitzen ein großes Potenzial als nachhaltiges Nahrungsmittel, das über Makro- und Mikronährstoffe verfügt, sowie als gesundheitsfördernde Nutraceuticals, die einen positiven Mehrwert für die menschliche Gesundheit liefern können. Dennoch steckt die Forschung zu ihnen noch in den Kinderschuhen und die nahe Zukunft wird Aufschluss darüber geben, ob sie auch in Zukunft fester Bestandteil unserer Ernährung werden. Microalgae are microscopic small photosynthetic organisms found in aquatic environments. They contain a variety of nutrients, including proteins, carbohydrates, carotenoids, vitamins, minerals and fatty acids. Nowadays, especially the green algae Chlorella and the cyanobacterium Arthrospira are found in food. The growing world population and limited farmland will lead to even greater food shortages in the next few years. For this reason, microalgae have been in the focus of science in recent years. In addition to a good nutrient profile, they are not dependent on agricultural land, but can be bred in ponds or photobioreactors. However, microalgae are still poorly distributed in the human diet. This could be because so far only a few of the over 200,000 species are approved for human consumption. Furthermore, especially the taste changes, which are associated with an increased microalgae content, and the high production costs play a major role. Nonetheless, microalgae contain a variety of bioactive components that have potential health benefits. In addition to immunomodulatory and anti-oxidative effects, they have prebiotic, anti-viral and detoxifying effects. In addition, microalgae are a vegan source of omega-3 fatty acids, which could help protect fish as a resource. Microalgae have great potential as a sustainable food with macro and micronutrients, as well as health-promoting nutraceuticals that can provide positive added value to human health. However, research on them is still in its infancy and the near future will tell if they will continue to be an integral part of our diet in the future.