Effects of Extracts from Tropical Seaweeds on DPPH Radicals and Caco-2 Cells Treated with Hydrogen Peroxide

Abstract

Edible seaweeds were collected from Indonesia, a tropical country that does not show seasonal variations in temperature, to evaluate their health-related activities. Ethanol and acetone extracts were prepared from -green and -brown algae. The ethanol and acetone extracts from Padina australis showed the strongest DPPH radical scavenging activity. These extracts also had the highest concentrations of total phenol and flavonoid. Both the ethanol and acetone extracts of the 0 Indonesian seaweeds decreased Caco-, cell viability when such cells were treated with 0** mM hydrogen peroxide. However, when Caco-, cells were treated with 1** or 2** mM hydrogen peroxide, the ethanol and acetone extracts from P. australis increased cell viability significantly more than those from the other seaweeds. This study indicates that organic extracts of seaweed have useful health-related functions.

Physiological Responses of Scenedesmus quadricauda (Chlorophyceae) to UV‐A and UV‐C Light

“…2). This is in accordance with a report from three green and some brown algae (10). Flavonoids are potent scavengers of ROS but neither total soluble phenols nor flavonoids were affected by UV exposure in our study, suggesting that expression of their biosynthetic genes requires longer exposure than that we used (1 h) and short‐term UV protection may sufficiently be covered by enhancement of antioxidative enzymes as mentioned above.…”

“…Phenols form considerable part of plant organic matter, therefore their quantitative changes in response to almost all environmental factors including UV light are not surprising (4,24). It should be noted that total soluble phenols detected in the present study were slightly higher than those in the leaves of Matricaria chamomilla (17) or Silene plants (25), indicating that algae are a potent source of bioactive phenols (10–12). Another interesting finding is that flavonoids form a major part of total soluble phenols (Fig.…”

“…Apart from antioxidative enzymes, plants also synthesize low molecular antioxidants such as phenolics which may directly or indirectly scavenge ROS (9). These compounds form a substantial part of plant organic matter and their considerable quantities have been found also in algae (10,11). However, quantification of specific phenols and their responses to UV light in algae are still absent.…”

Optimization of ultrasound‐assisted extraction conditions for phenolics, antioxidant, and tyrosinase inhibitory activities of Vietnamese brown seaweed (Padina australis)

“…Padina australis, one of the brown seaweeds found in some Southeast Asian countries including Vietnam, Malaysia, Indonesia and Thailand, belongs to the class Heterokontophyta and a member of Phaeophyceae. Bioactive compounds that have been isolated from this species including polyphenols, flavonoids, alkaloids, saponins, steroids, terpenoids, tannins, fucoxanthin and fatty acids (Gunji et al, 2007;Haryani et al, 2010;Salosso et al, 2020;Shiney & Wilsy, 2014) that has been found to possess antiangiogenic, antibacterial, antituberculosis, antioxidant and antimicrobial activity (Canoy & Bitacura, 2018;Chiao-Wei et al, 2011;Latifah et al, 2019;Yu et al, 2019).…”

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“…However, Dotulong et al, observed almost no activity from hexane, ethyl acetate and water fractions of Padina australis from North Sulawesi Nain Islandin DPPH assay 13 . In another study from Indonesia, P. australis ethanol and aceton extracts were evaluated in DPPH assay but the IC 50 values were rather high compared to other mentioned studies 14 .…”