Sunscreen, antioxidant, and bactericide capacities of phlorotannins from the brown macroalga Halidrys siliquosa

Abstract

00000 ăWOS:000390090300038International audienceThe present study focused on a brown macroalga (Halidrys siliquosa), with a particular emphasis on polyphenols and their associated biological activities. Two fractions were obtained by liquid/liquid purification from a crude hydroethanolic extract: (i) an ethyl acetate fraction and (ii) an aqueous fraction. Total phenolic contents and antioxidant activities of extract and both fractions were assessed by in vitro tests (Folin-Ciocalteu test, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, reducing power assay, superoxide anion scavenging assay, and beta-carotene-linoleic acid system). For the most active fraction, i.e., the ethyl acetate fraction, the oxygen radical absorbance capacity (ORAC) value, antibacterial activities, and sunscreen potential (Sun Protection Factor and UV-A-Protection Factor) were tested in vitro. A high correlation found between antioxidant activities and total phenolic content was interpreted as the involvement of polyphenolic compounds in antioxidant mechanisms. Interestingly, the ethyl acetate fraction appeared to be a broad-spectrum UV absorber and showed a strong bactericidal activity against Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli. In this fraction, four phenolic compounds (trifuhalols and tetrafuhalols and, for the first time, diphlorethols and triphlorethols) were identified using 1D and 2D nuclear magnetic resonance (NMR) and MS analysis. These findings are promising for the use of H. siliquosa, abundant in Brittany, as a valuable source of photoprotectant molecules for sunscreen and cosmetic applications

Extraction and Identification of Phlorotannins from the Brown Alga, Sargassum fusiforme (Harvey) Setchell

“…The results indicated that our extraction method was more efficient [33,34,35,36]. In addition, the DRSA of ethyl acetate fractions of S. fusiforme in our study (IC50 14.61 ± 0.56 μg·mL −1 ) was higher than those of some Sargassaceae species including Halidrys siliquosa (IC50 0.020 ± 3.54 × 10 −4 mg·mL −1 ) [28] and Cystoseira nodicaulis (IC50 14.00 ± 0.04 μg·mL −1 ). When compared with other brown seaweeds, it was lower than that of F. vesiculosus (IC50 4.00 ± 0.01 μg·mL −1 ), similar to that of Himanthalia elongate (IC50 14.00 ± 0.04 μg·mL −1 ), and stronger than that of F. serratus (IC50 14.00 ± 0.04 μg·mL −1 ).…”

Total phenolic content and biological activities of enzymatic extracts from Sargassum muticum (Yendo) Fensholt

“…Accumulation of these phloroglucinol-based phenolics contributes to the strong antioxidant activity against free radicalmediated oxidation damage (Kang et al 2012a;Fujii et al 2013). They also show other potential bioactivity such as a bactericidal, antiviral, and anticancer activity and radio protective and antiallergic effects (Li et al 2011;Eom et al 2012;Le Lann et al 2016).…”

Macroalgae-Derived Ingredients for Cosmetic Industry—An Update

“…Another study with Halidrys siliquosa (Phaeophyta) showed that the tested extracts presented strong antioxidant activity and a good sunscreen potential, associated with the presence of phlorotannins like diphlorethols, triphlorethols, trifuhalols, and tetrafuhalols [57].…”

“…To date, most of these marine-derived compounds were intended for food and pharmaceutical applications [38]. Also, several researchers have been exploring the effects of macroalgae on health, showing some progress and important positive outcomes in regards to some types of cancer; heart diseases; thyroid and immune functions; allergy; inflammation [54]; and antioxidant, antibacterial, and antiviral activity [55], among many others [42,56,57].…”

“…An O/W (oil in water) emulsion prepared with a phlorotannin-enriched fraction obtained from the brown macroalgae Halidrys siliquosa presented antibacterial capacity against Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli [57]. Another study with a red macroalgae (Pterocladia capillacea) revealed that using carbohydrate degrading enzymes prior to in vitro assays produced extracts with higher antioxidant capacity and stronger antibacterial effect against Escherichia coli and Staphylococcus aureus [61].…”