In Vivo Nutritional Assessment of the Microalga Nannochloropsis gaditana and Evaluation of the Antioxidant and Antiproliferative Capacity of Its Functional Extracts

Abstract

Nannochloropsis gaditana is a microalga with interesting nutritional and functional value due to its high content of protein, polyunsaturated fatty acids, and bioactive compounds. However, the hardness of its cell wall prevents accessibility to these components. This work aimed to study the effect of a treatment to increase the fragility of the cell wall on the bioavailability of its nutrients and functional compounds. The antioxidant and antiproliferative capacity of functional extracts from treated and untreated N. gaditana was assessed, and the profile of bioactive compounds was characterized. Furthermore, to study the effect of treatment on its nutrient availability and functional capacity, an in vivo experiment was carried out using a rat experimental model and a 20% dietary inclusion level of microalgae. Functional extracts from treated N. gaditana exhibited higher antioxidant activity than the untreated control. Furthermore, the treated microalga induced hypoglycemic action, higher nitrogen digestibility, and increased hepatic antioxidant activity. In conclusion, N. gaditana has interesting hepatoprotective, antioxidant, and anti-inflammatory potential, thus proving itself an ideal functional food candidate, especially if the microalga is treated to increase the fragility of its cell wall before consumption.

Bioactivity and Digestibility of Microalgae Tetraselmis sp. and Nannochloropsis sp. as Basis of Their Potential as Novel Functional Foods

“…In vivo investigations designed to understand the human digestion process of microalgae biomass are very scarce and further research is needed. Functional extracts obtained from untreated and treated N. gaditana , through a combined thermal and high-pressure treatment, were recently evaluated in vivo using a rat model with a 20% dietary inclusion level of microalgae [ 99 ]. Although both untreated and treated microalgae showed interesting potential for dry matter digestibility and antioxidant capacity (i.e., polyphenol content, ABTS and inhibition of lipid peroxidation), treated N. gaditana was able to improve all biomarkers.…”

“…In addition, the fecal microstructure of rats fed untreated N. gaditana clearly showed undigested microalgae and their microbiota was different compared to that of the rats fed the treated microalgae. It would suggest that the technological treatment not only favors the release of certain metabolites but could also promote the growth of specific microbiota [ 99 ]. Overall, we can conclude that microalgae biomass processing leading to cell disruption is a key factor for nutrient release and consequent digestibility of the compounds of interest.…”

Therapeutic Potentials of Microalgae and Their Bioactive Compounds on Diabetes Mellitus

“…A. platensis [23,28] H. pluvialis [29,30] C. vulgaris [31] D. salina [31] -Linoleic acid A. platensis [23,28] • Improves insulin secretion [32,33] • Improves insulin sensitivity [32,33] N. oculata [34] N. gaditana [35] D. salina [36] H. pluvialis [30] P. cruentum [37,38] C. vulgaris [39] Arachidonic acid (AA)…”

“…A. platensis [23,28] • Improves blood sugar level [40,41] • Improves glucose tolerance [40] • Improves insulin secretion [41] • Improves insulin sensitivity [40] • Protects pancreatic cells [40] N. gaditana [35] H. pluvialis [30] P. cruentum [37,38] C. vulgaris [39] Table 1. Cont.…”

“…Eicosapentaenoic acid (EPA) A. platensis [23,28] • Improves blood sugar level [42] • Improves insulin sensitivity [42] N. oculata [34] N. gaditana [35] C. pyrenoidosa [43] H. pluvialis [30] P. cruentum [37,38] C. vulgaris [39] Docosahexaenoic acid (DHA)…”