The Potential of Microalgae for the Production of Bioactive Molecules of Pharmaceutical Interest

Abstract

Through the photosynthetic activity, microalgae process more than 25% of annual inorganic carbon dissolved in oceans into carbohydrates that ultimately, serve to feed the other levels of the trophic networks. Besides, microalgae synthesize bioactive molecules such as pigments and lipids that exhibit health properties. In addition, abiotic stresses, such as high irradiance, nutrient starvation, UV irradiation, trigger metabolic reorientations ending with the production of other bioactive compounds such as ω-3 fatty acids or carotenoids. Traditionally, these compounds are acquired through the dietary alimentation. The increasing, and often unsatisfied, demand for compounds from natural sources, combined with the decrease of the halieutic resources, forces the search for alternative resources for these bioactive components. Microalgae possess this strong potential. For instance, the diatom Odontella aurita is already commercialized as dietary complement and compete with fish oil for human nutrition. In this contribution, the microalga world is briefly presented. Then, the different types of biologically active molecules identified in microalgae are presented together with their potential use. Due to space limitation, only the biological activities of lipids and pigments are described in details. The contribution ends with a description of the possibilities to play with the environmental constrains to increase the productivity of biologically active molecules by microalgae and by a description of the progresses made in the field of alga culturing.

Photosynthesis under artificial light: the shift in primary and secondary metabolism

“…In higher plants, it has been documented that depending on species and growing conditions, the secondary metabolites and pigments in the flavonoid family accumulate under photoinhibitory conditions at cell level [41], although the mechanistic aspects of LED light effects are not well understood. The high fluence effect of LED light has been studied more in photosynthetic microorganisms, partly because they present huge biotechnological and economic potential (biofuels, pharmaceuticals, food additives and cosmetics) [42]. For instance, Wang et al [43] assessed the economic efficiency of energy converted to biomass in microalga (Spirulina platensis) culture under different LED monochromatic lights as grams of biomass per litre per dollar.…”

Can Microalgae Act as Source of Preservatives in Food Chain?

“…Vitamins, polyphenols and carotenoids are considered the most natural antioxidant molecules [14][15][16][17]. Due to their high antioxidant power, the polyphenols are considered among the most interesting and relevant natural compounds to be used as food preservatives and bioactive ingredients in medicine, crops treatment, food and feed formulation and food package [4,18,19].…”

Towards the Clinical Use of Phytoplankton Carotenoid Pigments to Cure Cancer

“…Beyond their well-known antioxidant activity, used as a commercial argument to sell algae-based cosmetics and nutraceutics, it is now clearly established that microalgae pigments have a great potential as health nutrients to prevent cancer, as biotechnological probes for cancer diagnosis and as anticancer drugs to trigger cancer cells apoptosis, prevent tumor angiogenesis, reduce the risk of metastasis, sensitize cancer cells to chemotherapy, destroy cancer cells by tumor phototherapy and filter UV to limit cancer cells initiation. Numerous studies aiming to identify antiproliferative molecules from microalgae extracts led to the isolation of carotenoids and to the demonstration of their high antiproliferative, cytostatic, cytotoxic, and/or pro-apoptotic activity in cancer cell cultures [1,2]. As an example, our research team performed the bioguided isolation of pigments from Duniella tertiolecta and found that violaxanthin was the most antiproliferative molecule contained in Dt dichloromethane extract [3].…”