Microalgae with Immunomodulatory Activities

Abstract

Microalgae are photosynthetic microorganisms adapted to live in very different environments and showing an enormous biochemical and genetic diversity, thus representing an excellent source of new natural products with possible applications in several biotechnological sectors. Microalgae-derived compounds have shown several properties, such as anticancer, antimicrobial, anti-inflammatory, and immunomodulatory. In the last decade, compounds stimulating the immune system, both innate immune response and adaptive immune response, have been used to prevent and fight various pathologies, including cancer (cancer immunotherapy). In this review we report the microalgae that have been shown to possess immunomodulatory properties, the cells and the cellular mediators involved in the mechanisms of action and the experimental models used to test immunostimulatory activities. We also report information on fractions or pure compounds from microalgae identified as having immunostimulatory activity. Given the increasing interest in microalgae as new eco-friendly source of bioactive compounds, we also discuss their possible role as source of new classes of promising drugs to treat human pathologies.

Lysophosphatidylcholines and Chlorophyll-Derived Molecules from the Diatom Cylindrotheca closterium with Anti-Inflammatory Activity

“…Microalgae, and in particular diatoms, therefore, can be considered potentially important producers of compounds to prevent and treat different human pathologies. In recent years they have been shown to have anti-inflammatory, antimicrobial, anticancer, antidiabetic, antiepileptic and even antituberculosis properties [10][11][12][49][50][51][52][53][54][55]. A better understanding of the potential health benefits from these marine organisms, the compounds they produce, and the environmental conditions affecting their production should allow for the sustainable development of these valuable marine resources in the future.…”

Photosymbiosis for Biomedical Applications

“…In this context, alginate has demonstrated to be effective in protecting different cell types ( Carroll et al, 2019 ; Ghanta et al, 2020 ) upon implantation, as well as more complex structures like pancreatic islets ( Barkai et al, 2016 ). Besides, both microalgae and cyanobacteria could be genetically modified to locally release immunomodulatory factors, in addition to the compounds many of them already produce ( Riccio and Lauritano, 2020 ), or as recently described, engineered to be coated with immunocompatible envelopes ( Qiao et al, 2020 ). However, it would be far more interesting to search for immunotolerant photosynthetic microorganisms capable of establishing long-term relationships with humans.…”

“…Still more impressive is the number and variety of applications that have been found for alga- and cyanobacteria-derived secondary metabolites. The list now includes more than 140 different molecules including polysaccharides, amino acids, carotenoids, isoprenoids, sterols, polyphenolic compounds, fatty acids and halogenated compounds, which are pharmaceutically active when employed as antiviral, antimicrobial and anti-inflammatory agents ( Riccio and Lauritano, 2020 ). Besides their value as nutraceuticals, some have shown promising results as anticarcinogenic and antitumor compounds for several multidrug-resistant and advanced cancer types.…”

The Inclusion of the Microalga Scenedesmus sp. in Diets for Rainbow Trout, Onchorhynchus mykiss, Juveniles

“…was also reported to promote immunity in broiler chickens [96]. Differences among studies with similar or different microalgal species may be due to variations in their inclusion levels, diet formulation, microalgal cell wall composition and content in bioactive compounds [97]. Nevertheless, in order to access the real immune potential of the dietary inclusion of Scenedesmus sp., further analysis considering an in vitro or in vivo infectious challenge should be considered.…”