Microalgae as Potential Sources of Bioactive Compounds for Functional Foods and Pharmaceuticals

Abstract

Microalgae are an untapped source of bioactive compounds with various biotechnological applications. Several species are industrially produced and commercialized for the feed or cosmetic industries, however, other applications in the functional food and pharmaceutical markets can be foreseen. In this study, nine industrial/commercial species were evaluated for in vitro antioxidant, calcium-chelating, anti-tumoral, and anti-inflammatory activities. The most promising extracts were fractionated yielding several promising fractions namely, of Tetraselmis striata CTP4 with anti-inflammatory activity (99.0 ± 0.8% reduction in TNF-α production in LPS stimulated human macrophages at 50 µg/mL), of Phaeodactylum Tricornutum with cytotoxicity towards cancerous cell lines (IC50 = 22.3 ± 1.8 μg/mL and 27.5 ± 1.6 μg/mL for THP-1 and HepG2, respectively) and of Porphyridium sp. and Skeletonema sp. with good chelating activity for iron, copper and calcium (IC50 = 0.047, 0.272, 0.0663 mg/mL and IC50 = 0.055, 0.240, 0.0850 mg/mL, respectively). These fractions were chemically characterized by GC–MS after derivatization and in all, fatty acids at various degrees of unsaturation were the most abundant compounds. Some of the species under study proved to be potentially valuable sources of antioxidant, metal chelators, anti-tumoral and anti-inflammatory compounds with possible application in the functional food and pharmaceutical industries.

Tisochrysis lutea as a Substrate for Lactic Acid Fermentation: Biochemical Composition, Digestibility, and Functional Properties

“…Increased pigment (carotenoid) extractability could not fully explain the increased antioxidant activity, which might be partly due to the presence of other compounds of microalgal or bacterial origin. Silva et al [ 82 ], for an ethyl acetate extract from the biomass of a commercial T. lutea , obtained an IC 50 of 0.8 g L −1 , more than half that for lipophilic extracts in this work (about 1.7–1.8 g L −1 ). A water extract from Pavlova lutheri KMCC H-006 fermented with the yeast Hansenula polymorpha showed an IC 50 value of 0.3 g L −1 [ 83 ], an activity much higher than that of the extract in 30% EtOH in water obtained from fermented biomass in the present work, which did not reach values exceeding 50%, making it impossible to calculate IC 50 .…”

Bioactive compounds by microalgae and potentials for the management of some human disease conditions

“…It was concluded that there was compelling evidence for the benefits of microalgal compounds, but further research on their digestive mechanism is required. This has been reiterated by other workers [82] – [83] who posited that fermentation of microalgae has potential, but it is still a fairly new area. It was suggested that more work should be carried out to ascertain the true composition of microalgae to enable manipulation into other products.…”

Microalgae from Nordic collections demonstrate biostimulant effect by enhancing plant growth and photosynthetic performance

“…The genetic diversity of microalgae is an unfathomed source of bioactive compounds for multivarious products, such as pharmaceuticals, nutraceuticals, biopesticides, and biostimulants (González‐Pérez et al, 2021; Silva et al, 2022). Plant biostimulants facilitate nutrient uptake, improve crop performance and tolerance to abiotic stress, and therefore can have a crucial role in reducing dependency on synthetic fertilizers and plant protection products, and thus address agronomic sustainability challenges (Chiaiese et al, 2018).…”