Antioxidant properties of the red alga Asparagopsis taxiformis collected on the North West Algerian coast

Abstract

The aim of the present study was to evaluate the total phenolic and lipid content, fatty acids profiles and in vitro antioxidant activities of aqueous and solvent extracts of the red seaweed Asparagopsis taxiformis, through six different investigations. The present study demonstrated that phenol contents (mg gallic acid/g dry weight) were highest in the aqueous and methanolic extracts, followed by the ethanolic, hydroethanolic and hydromethanolic extracts. The lowest phenol contents were identified in the three remaining extracts: Butanolic, petroleum ether and acetone extracts. Furthermore, the total lipid content of the algae powder amounted to 2.85% of dry weight. The fatty acid methyl ester profiles analysed by gas-liquid chromatography represented indicated that fatty acids comprised 91.0±0.3% of total algae lipids. The saturated to unsaturated fatty acid contents amounted to 23.2±0.1 and 67.9±0.4% respectively. C13:0 (tridecanoate), C15:0 (pentadecanoate) and C17:0 (heptadecanoate) represented 47.4% of the total saturated fatty acids. Notably, the two most abundant unsaturated fatty acids, C15:1 (pentadecenoate) and C18:2 (octadecadienoate) represented 13.4 and 11.4% respectively, of the total unsaturated fatty acid content. Furthermore, the results of the antioxidant screening performed at 1.0 mg/ml, revealed that aqueous and methanolic extracts exhibited higher inhibition against superoxide and nitric oxide radicals and excellent radical scavenging activity [with half maximal inhibitory concentration (IC50) values 5.1 and 15.0 µg/ml, respectively], demonstrating improved antioxidant behavior when compared with standard ascorbic acid (which has an IC50 value of 3.7 µg/ml). Scavenging activity of the aqueous and methanolic extracts exhibited a strong peroxidation inhibition against linoleic acid emulsion system at a concentration of 300 µg/ml in comparison to the butylated hydroxyltoluene. Although all the studied extracts exhibited ferric reducing power, the aqueous and methanolic extracts had greater hydrogen donating ability. By contrast, hydromethanolic, ethanolic, hydroethanolic, butanolic, acetone and petroleum ether extracts exhibited weak antioxidant behavior. The antioxidant activity of potent seaweed species identified in the current study means that as well as being used as a functional food, they may be developed as novel pharmaceutical compounds and may be used as anti-ageing agents.

Antioxidant and cytotoxic activities of sulfated polysaccharides from five different edible seaweeds

“…This sulfate group of sugar moieties is found responsible for exhibiting anionic charge to the polymers [27,39,40]. Antibacterial and antiviral activity of anionic seaweed sulfated polysaccharides exhibit by binding the positively charged glycoprotein virus envelope and bacteria cell surface thereby integrating with virus or bacteria thus it prevent the pathogens entry into host cells [42][43][44]. Positive charge glycoprotein receptor of bacteria cell surface bind sulfate polysaccharides thereby inhibiting the bacteria [44].…”

Nutraceutical potential of Asparagopsis taxiformis (Delile) Trevisan extracts and assessment of a downstream purification strategy

“…Mellouk et al. (2017) [28] also provided some insight of the antioxidant properties of A. taxiformis from the Algerian coast and water extraction resulted in the highest yield (24.0 g/100g dw), followed by methanol extract (21.3 g/100g dw) and ethanol extract (18.1g/100g dw). Although comparing A. taxiformis from different locations and time of harvest, the extract yield were in similar order with higher extraction yield using water, followed by methanol and ethanol solvents.…”

“…Mellouk et al. (2017) [28] also evaluated A. taxiformis of which water, methanol and ethanol extracts also produced good DPPH scavenging activity, using an extract concentration lower than 0.2 mg/ml. Statistical analysis was performed, and Tukey's b test determined that in M1 there are four distinct groups, highlighting the intrinsic capability of each solvent to produce a different extract with singular scavenging activity.…”

“…According to Mellouk et al. (2017) [28] , 2.85 g/100g dw of lipids could be extracted from Algerian A. taxiformis of which 91% are FAME, comprised of 23% saturated and 68% unsaturated fatty acids. The different yield obtained in our work could be due to different extraction technics or due to the natural variations in biocompounds within the A. taxiformis seaweed, that occur throughout the year or being located in different sites, in this case in the Atlantic Ocean and Mediterranean Sea, respectively.…”

Chemical Composition and Nutritional Value of Different Seaweeds from the West Algerian Coast

“…Previous studies related to seaweeds from the Algerian coast can be considered scarce. Chemical and biological evaluation of the nutritive value of Ulva lactuca has been done (Zitouni et al, 2014), while the antioxidant properties of Asparagopsis taxiformis (Mellouk et al, 2017) and the antimicrobial behaviour of a combined ethanol-aqueous extract of Cystoseira compressa have been demonstrated (Oucif et al, 2018). Knowledge of the chemical composition and nutritional value is necessary so that utilisation of algae from such a North African coast can be increased and they can be widely exploited commercially.…”