Unlocking the Health Potential of Microalgae as Sustainable Sources of Bioactive Compounds

Abstract

Microalgae are known to produce a plethora of compounds derived from the primary and secondary metabolism. Different studies have shown that these compounds may have allelopathic, antimicrobial, and antipredator activities. In addition, in vitro and in vivo screenings have shown that several compounds have interesting bioactivities (such as antioxidant, anti-inflammatory, anticancer, and antimicrobial) for the possible prevention and treatment of human pathologies. Additionally, the enzymatic pathways responsible for the synthesis of these compounds, and the targets and mechanisms of their action have also been investigated for a few species. However, further research is necessary for their full exploitation and possible pharmaceutical and other industrial applications. Here, we review the current knowledge on the chemical characteristics, biological activities, mechanism of action, and the enzymes involved in the synthesis of microalgal metabolites with potential benefits for human health.

Keywords: bioactive molecules; marine biotechnology; microalgae; pharmaceuticals.

Figure 5

Summary of main anti-cancer effects induced by microalgal compounds. ROS is the abbreviation for reactive oxygen species.

Figure 1

A schematic representation of microalga biomass for different applications.

Figure 2

The chemical structure of the pigments: (a) Fucoxanthin; (b) β-carotene; (c) Astaxanthin; (d) Violaxanthin; (e) Lutein.

Figure 3

The effects of bioactive compounds extracted from microalgae involved in anti-inflammatory mechanisms. NF-kB stands for nuclear factor-kappa B, IL for interleukin, TNF for tumor necrosis factor, IFN for interferon, iNOS for inducible nitric oxide synthase, NO for nitric oxide, COX-2 for cyclo-oxygenase-2 and PGE2 for prostaglandin E2.

Figure 4

The chemical structure of polyunsaturated aldehydes. (a) 2-trans-4-cis-7-cis-decatrienal; (b) 2-trans-4-trans-7-cis-decatrienal; (c) 2-trans-4-trans-decadienal.

Figure 6

Examples of (a) long chain, amphidinol 22; (b) short chain, amphidinol 18; (c) sulfonated amphidinols, amphidinol 19.

Figure 7

(a) Amphirionin-2 and (b) amphirionin-5. Two polyketides from the same family, but opposite bioactivities.

Figure 8

(a) Amphidinolides N; (b) Amphidinolides H. Amphidinolides with the highest cytotoxicity.

Figure 9

Bidimensional structure of tetrodotoxin.

Figure 10

Bidimensional structure of yessotoxin.

Figure 11

Bidimensional structure of gymnodimine.

Figure 12

Bidimensional structure of brevenal.