Antioxidant Activity of Various Solvent Fractions from Edible Brown Alga, Eisenia bicyclis and Its Active Compounds

Abstract

In this study, we aimed to elucidate the antioxidant capacity of Eisenia bicyclis and evaluated its antioxidant activity using various assay systems such as 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, 2,2-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging, reducing power ability, and content of total polyphenol. Among all the performed experiments, the ethyl acetate fraction of E. bicyclis exhibited higher antioxidant activities. From this finding, isolation and purification were performed on the ethyl acetate fraction and identified dieckol and phlorofucofureoeckol-A by spectroscopic analyses including FAB-mass in the negative mode, (1) H NMR, (13) C NMR, (1) H-(1) H COSY, HMQC, and HMBC spectra. Interestingly, ABTS radical scavenging activities of dieckol and phlorofucofuroeckol showed strong effects of 65.36% and 70.38% at a concentration of 50 μg/mL, respectively. DPPH radical scavenging and reducing power abilities were increased in a dose-dependent manner at various concentrations. These results suggest that dieckol and phlorofucofuroeckol-A of E. bicyclis may play an important role in protection from oxidative stress involving reactive oxygen species and may contribute to the development of new bio products, for example, a useful preservative to improve food quality and a drug for various oxidative damage-associated diseases. Practical Application: The results suggest that dieckol and phlorofucofuroeckol-A can be utilized as a natural source for potential application of antioxidant in food industry and drug for oxidative damage-associated diseases.

Antioxidant activity and chemical compositions of essential oil and ethanol extract of Chuanminshen violaceum

“…It is revealed that the DPPH radical scavenging activity was increased by the total phenolic content. This result is in accordance with that reported by Kwon et al (2013), who revealed the positive relationship between the DPPH radical scavenging activity and the increasing of phenolic contents.…”

“…The total phenolic content (TPC) of the ethanol extract and its fractions was determined by the literature methods involving Folin-Ciocalteu reagent and gallic acid standard (Kukula-Koch et al, 2013;Kwon et al, 2013). 1 mL of sample was mixed with 0.5 mL of Folin-Ciocalteu reagent and 5 mL of distilled water.…”

6,6′‐Bieckol inhibits adipocyte differentiation through downregulation of adipogenesis and lipogenesis in 3T3‐L1 cells

“…18,19 The results indicated that these purified compounds had strong antioxidant effects. However, the anti-obesity effects of these E. bicyclis compounds and the underlying mechanism remain unknown.…”

“…18,19 Briefly, dried E. bicyclis powder (1.3 kg) was extracted twice with methanol at room temperature for 2 days. Following removal of MeOH under reduced pressure, the resulting solution was partitioned between chloroform and H 2 O, followed by ethyl acetate and H 2 O.…”

Brown algae phlorotannins enhance the tumoricidal effect of cisplatin and ameliorate cisplatin nephrotoxicity

“…ROS formation can activate the Akt pathway, which is upstream of the NFκB pathway, and can therefore induce activation of NFκB [34]. Notably, many sea and terrestrial polyphenols are generally recognized as antioxidants and show cytoprotective effects in some cells by reducing ROS levels [20,[35][36][37]. These observations suggest that polyphenols can act as a double-edged sword, both as an antioxidant and a prooxidant.…”