Assessment of antioxidant activity in Victorian marine algal extracts using high performance thin-layer chromatography and multivariate analysis

Abstract

The aim of this study was to develop and validate a rapid and simple high performance thin layer chromatographic (HPTLC) method to screen for antioxidant activity in algal samples. 16 algal species were collected from local Victorian beaches. Fucoxanthin, one of the most abundant marine carotenoids was quantified directly from the HPTLC plates before derivatization, while derivatization either with 2,2-diphenyl-1-picrylhydrazyl (DPPH) or ferric chloride (FeCl) was used to analyze antioxidants in marine algae, based on their ability to scavenge non biological stable free radical (DPPH) or to chelate iron ions. Principal component analysis of obtained HPTLC fingerprints has classified algae species into 5 groups according to their chemical/antioxidant profiles. The investigated brown algae samples were found to be rich in non-and moderate-polar compounds and phenolic compounds with antioxidant activity. Most of the phenolic iron chelators also have shown free radical scavenging activity. Strong positive and significant correlations between total phenolic content and DPPH radical scavenging activity showed that, phenolic compounds, including flavonoids are the main contributors of antioxidant activity in these species. The results suggest that certain brown algae possess significantly higher antioxidant potential when compared to red or green algae and could be considered for future applications in medicine, dietary supplements, cosmetics or food industries. Cystophora monilifera extract was found to have the highest antioxidant concentration, followed by Zonaria angustata, Cystophora pectinate, Codium fragile, and Cystophora pectinata. Fucoxanthin was found mainly in the brown algae species. The proposed methods provide an edge in terms of screening for antioxidants and quantification of antioxidant constituents in complex mixtures. The current application also demonstrates flexibility and versatility of a standard HPTLC system in the drug discovery. Proposed methods could be used for the bioassay-guided isolation of unknown natural antioxidants and subsequent identification if combined with spectroscopic identification.

Pressurized Liquid Extraction (PLE) as an Innovative Green Technology for the Effective Enrichment of Galician Algae Extracts with High Quality Fatty Acids and Antimicrobial and Antioxidant Properties

“…The best dose-response activity was observed for F. vesiculosus followed by C. baccata and H. elongata with a capacity of inhibiting 50% of DPPH (IC 50 ) at 7.17 ± 0.01 μg/mL ( F. vesiculosus ), 28.49 ± 3.80 μg/mL ( C. baccata ) and 64.89 ± 6.64 μg/mL ( H. elongata ). Our results concord with previous studies which describe green algae have lower free radical scavenging activities when compared to brown algae [ 25 , 26 , 27 ]. While high IC 50 values are found for pure or aqueous methanol extracts from Ulva species such as U. clathrata (715 μg/mL) [ 28 ], U. prolifera (3026 μg/mL) [ 28 ] and U. compresa (>1000 μg/mL) [ 26 ], low IC 50 values are observed in pure or aqueous methanol/ethanol extracts from Cystoseira species like C. sedoides (27 μg/mL) [ 29 ], C. baccata (28 μg/mL), C. usneoides (55 μg/mL) [ 26 ], C. osmundacea (69 μg/mL) [ 27 ] and C. tamariscifolia (109 μg/mL) [ 26 ].…”

Cytotoxic Activity of Extract and Active Fraction of Turbinaria decurrens Bory on Colon Cancer Cell Line HCT-116

“…Fucoxanthin content. Fucoxanthin is main component of non-provitamin A carotenoid and has free radical scavenging activity due to unusual allenic double bonds (C=C=C) that is believed to be responsible for its higher antioxidant activity (Agatonovic-Kustrin et al, 2016). Fucoxanthin has been investigated as antitumor and cancer-preventative function that indicate inducing G1 cell-cycle arrest and apoptosis in various cell lines (Satomi, 2017).…”

Essential Oil Quality and Purity Evaluation via FT-IR Spectroscopy and Pattern Recognition Techniques

“…Many studies have reported on the use of chemometric tools to classify plant foods. For example, principal component analysis (PCA) was used to outline of the similarities and differences among 16 algal species and to classify 40 wine samples based on their high-performance thin-layer chromatography (HPTLC) fingerprints [18,19]. It is well known that each plant species has a special, complex mixture of bioactive natural products, in which each component contributes to its overall bioactivity.…”