• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.3
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• pp.133-140
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• 2007

In 2006, we studied herbivore consumption rate and preference for algal species using laboratory experiments. In the no-choice feeding experiment, three herbivores (two sea urchins, Stronglyocentrotus nudus and Stronglyocentrotus intermedius and an abalone, Haliotis discus hannai) showed significantly (P<0.05) distinct preferences for four algae (Laminaria japonica, Undaria pinnatifida, Costaria costata and Ecklonia stolonifera). The alga preferred by S. nudus was L. japonica followed by U. pinnatifida, C. costata and E. stolonifera with respective daily feeding rates of $5.7{\pm}:0.85\;g,\;4.4{\pm}0.89\;g,\;3.1{\pm}0.39\;g\;and\;2.1{\pm}0.32\;g(mean{\pm}SE)$. A similar trend was found for S. intermedius. Interestingly, the herbivore consumption rates for the algae differed with or without competition. The competition stimulated the feeding activity for S. nudus, but lowered the activity for S. intermedius. The multi-choice feeding experiment confirmed that L. japonica was significantly preferred by two herbivores: S. nudus and H. discus hannai (Duncan's multiple range test, ANOVA, p<0.05).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.5
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• pp.532-539
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• 2010

Seaweed biomass was estimated in the rocky subtidal zone of Daejin on the mid-east coast of Korea using a destructive sampling method from February to November 2007. Monthly sampling was conducted at depths of 5, 10 and 15 m using 50 $\times$ 50 cm quadrats. A total of 73 species, including 5 chlorophytes, 25 phaeophytes, 43 rhodophytes and one seagrass were identified. Average seaweed biomass was 2,852.3 g wet wt. $m^{-2}$ and biomass values varied monthly from 1,189.8 g to 7,523.7 g. The species dominant in biomass were Laminaria japonica (481.7 g), Sargassum confusum (470.85 g), Undaria pinnatifida (422.57 g), Costaria costata (282.16 g), Odonthalia corymbifera (174.46 g), S. sagamianum (163.22 g) and S. horneri (122.18 g). The vertical distribution of algae was characterized by S. confusum and U. pinnatifida at 5 m, L. japonica and U. pinnatifida at 10 m, and O. corymbifera and L. japonica at 15 m depth. The C/P, R/P and (R+C)/P values were 0.20, 1.72 and 1.92, respectively.

• Natural Product Sciences
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• v.18 no.3
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• pp.153-157
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• 2012

Obesity, which is characterized by excessive fat accumulation in adipose tissues, occurs by fat absorption by lipase and sequential fat accumulation in adipocyte through adipocyte differentiation. Thus, inhibition of pancreatic lipase activity and adipocyte differentiation would be crucial for the prevention and progression of obesity. In the present study, we attempted to evaluate anti-adipogenic activity of several algae extracts employing preadipocytes cell line, 3T3-L1 as an in vitro assay system. The effects on pancreatic lipase activity in vitro were also evaluated. Total methanolic extracts of Cladophora wrightiana and Costaria costata showed significant inhibitory activity on adipocyte differentiation as assessed by measuring fat accumulation using Oil Red O staining. Related to pancreatic lipase, C. wrightiana and Padina arborescens showed significant inhibition. Further fractionation of C. wrightiana, which showed the most potent activity, suggested that $CHCl_3$ and n-BuOH fraction are responsible for adipocyte differentiation inhibition, whereas n-BuOH and $H_2O$ fraction for pancreatic lipase inhibition. Our study also demonstrated that n-BuOH fraction was effective both in early and middle stage of differentiation whereas $CHCl_3$ fraction was effective only in early stage of differentiation. Taken together, algae might be new candidates in the development of obesity treatment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.4
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• pp.443-449
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• 2012

This study was conducted to investigate the antioxidant and acetylcholinesterase (AChE) inhibitory activities of extracts from various seaweed. The extracts of $Sargassum$ $thunbergii$ (91.3%), $Polysiphonia$ $morrowii$ (90.7%), $Ecklonia$ $cava$ (89.9%), and $Artemisia$ $fukudo$ (85.9%) showed over 80% high radical scavenging activities at the final concentration of 40 ${\mu}g$/mL. The $Artemisia$ $fukudo$ extract showed the highest inhibition activity of 30.2% on AChE at the final concentration of 10 ${\mu}g$/mL. The extract of $Porphyra$ $tenera$, $Costaria$ $costata$, $Monostroma$ $nitidum$, $Ecklonia$ $cava$, and $Agarum$ $clathratum$ against AChE at a concentration of 10 ${\mu}g$/mL exhibited inhibition of 26.6%, 25.3%, 23.4%, 21.7%, 20.4% and 19.9%, respectively. The bioautography results showed that the mixtures of structurally diverse compounds were thought to affect AChE inhibitory activity. These results suggest that extracts from seaweed with their high quality components may be effective in the prevention of Alzheimer's disease and may be used to develop various functional food products.