Bio‐Prospecting of a Few Brown Seaweeds for Their Cytotoxic and Antioxidant Activities

Abstract

Methanolic extracts (MEs) of seven brown seaweeds occurring in the Indian coastal waters were screened for their cytotoxic and antioxidant properties following various assays. The methanolic extracts of seaweeds in the order of Dictyopteris australis > Spatoglossum variabile > Stoechospermum marginatum > Spatoglossum aspermum showed significant cytotoxic activity. A very high DPPH radical scavenging activity was exhibited by the methanolic extracts prepared from St. marginatum, Padina tetrastromatica, Dictyopteris delicatula and S. aspermum. The total phenolic content of the MEs varied from 13.19 ± 0.32 to 25.29 ± 0.445 gallic acid equivalents (mg g−1 of methanolic extract). The reducing power assay indicated a dose dependency, at concentrations of 0.1, 0.5 and 1.0 and 2.0 mg mL−1 of MEs and decreased in the following order: Butylated hydroxy toluene > P. tetrastromatica > D. delicatula > S. aspermum > S. variabile > S. marginatum > D. australis > S. marginatum. Furthermore, D. australis, S. aspermum, S. variabile and S. marginatum demonstrated good metal ion chelating properties. All the above evidences suggest that, the antioxidant compounds found in brown seaweeds scavenge free radicals through effective intervention. This decisively promotes them as a potential source of natural antioxidants.

<b><i>In vitro</i> evaluation of antioxidant activity of methanolic extracts obtained from seaweeds endemic to the coast of Ceará, Brazil

“…High levels of TPC in brown marine algae are expected, considering reports indicating they are rich sources in fucoxanthin (D'Orazio et al, 2012) and phlorotannins (Wang et al, 2012). Similar results were also described by Wang et al (2009) (Vinayak, Sabu, & Chatterji, 2011), whose values were very similar to the methanolic extracts from the brown seaweeds D. dichotoma and S. vulgare analyzed in this study.…”

“…These results were higher than those obtained for A. multifida and C. crenulata, which were from 50 (100 μg mL -1 ) to 400 (12.5 μg mL -1 ) times less concentrated. Among the methanol extracts of brown seaweeds analyzed by Vinayak et al (2011), Dictyopteris australis showed FIC approximately 16% higher than the extracts of Dictyota dichotoma and Sargassum vulgare at 100 mg L -1…”

Antioxidant potential and cytotoxic activity of two red seaweed species, Amansia multifida and Meristiella echinocarpa, from the coast of Northeastern Brazil

“…Produced endogenously in cellular tissues, reactive oxygen species (ROS), such as the hydroxyl radical (OH˙), superoxide radical (O 2ˉ) , hydroperoxyl radical (HO 2˙) , hydrogen peroxide (H 2 O 2 ) and singlet oxygen ( dysfunction, muscular dystrophy, ischemia, tissue damage and neurological disorders (Vinayak et al 2011a, b, Wang et al 2011, Yangthong et al 2009). …”

Antimicrobial Properties of Sargassum spp. (Phaeophyceae) against Selected Aquaculture pathogens

“…Among the tested brown seaweeds, Sargassum polycystum exhibited the better antimicrobial activity that has potentially used as antimicrobial agent and as natural immunostimulant with aquaculture industry for the treatment of microbial diseases and improvement of the health status of commercially important aquaculture species. minerals, vitamins, essential amino acids, fatty acid, dietary fiber and carbohydrates and as long as food, agricultural fertilizers and drugs have been used (Dawczynski et al, 2007), and the context of radical scavenging properties seaweeds possess natural antioxidants such as carotenoids, pigments, polyphenols, enzymes and diverse functional polysaccharides (Vinayak et al, 2011). The use of seaweeds are inexpensive than chemicals and antibiotics and have little effects on nature, humans and fish.…”