The experiment was conducted to investigate the effects of different algae in diet on growth, survival, and interleukin-10 productions of sea cucumber. At first, a 9-week feeding trail was conducted to evaluate the growth performance and survival of the sea cucumber fed one of the six experimental diets containing ST (Sargassum thunbergii), UL (Ulva lactuca), UP (Undaria pinnatifida), LJ (Laminaria japonica), SS (Schizochytrium sp.), and NO (Nannochloropsis oculata) in a recirculating aquaculture system. The result showed that survival was not significantly different among the dietary treatments, and the specific growth rate (SGR) of sea cucumber fed the UL diet (1.58% d ) was significantly higher than that of sea cucumber fed the other diets (P < 0.05), except for the LJ and NO diets. Secondly, interleukin (IL)-10 gene expression was determined where mice splenocytes were stimulated with 10 μg ml −1 of sea cucumber extracts for 2 h. The result showed that IL-10 gene expression levels were significantly increased in UL, LJ, and NO diets fed sea cucumber extracts compared to other experimental diets. The results suggest that dietary inclusion with Ulva lactuca, Laminaria japonica, and Nannochloropsis oculata algae may improve the growth of juvenile sea cucumber and could upregulate IL-10 gene expression in mice splenocytes. Such detailed information could be helpful in further development of more appropriate diets for sea cucumber culture.

Two experiments were conducted to investigate the effects on growth, survival and anti-inflammatory cytokine (Interleukin-10) using with Nannochloropsis concentration in diets of sea cucumber Apostichopus japonicus. In the first experiment, 60 days feeding trail was conducted to evaluate the growth performance and survival of the sea cucumber fed on six experimental diets containing different inclusion level of Nannochloropsis oculata (0%, 2%, 4%, 6%, 8%, 10%) in recirculating aquaculture system. Specific growth rate (SGR) and food conversion efficiency (FCE) of sea cucumber fed diet containing 8% Nannochloropsis oculata algae was significantly higher than that of other diets (P<0.05). Results of the experiment suggest that dietary inclusion with 8% Nannochloropsis oculata may improve growth of sea cucumber. The second experiment was conducted to determine IL-10 gene expression where mice splenocytes were stimulated with 10 µg/ml of each diet fed sea cucumber extracts for 2 hours. The result showed that IL-10 gene expression levels were significantly increased in 6% and 8% Nannochloropsis oculata algae containing diets fed sea cucumber extracts. This result suggests that proper combination of Nannochloropsis oculata could up-regulate of IL-10 gene expression. Such detailed information could be helpful in further development of more appropriate diets for sea cucumber culture.

No abstract

Effect of ascidian (Halocynthia roretzi, Drasche 1884) tunics carotenoids on enhancing growth and muscle coloring of sea-reared rainbow trout (Oncorhynchus mykiss, Walbaum 1792) a b s t r a c t A 120 days trial was conducted to investigate the effect of sea squirt (Halocynthia roretzi, Drasche 1884) tunic's carotenoid to sea-reared rainbow trout (Oncorhynchus mykiss, Walbaum 1792) growth and muscle color. Sea-rearing was done at Tongyeong sea area, Korea. Three dietary treatments, namely control (C), CT, and AT, were administered to 6 groups of fish (n = 490-520). C was given basal diet which has contained 40 mg kg −1 of astaxanthin. A further inclusion of 10 mg kg −1 canthaxanthin was added to diet of CT, while AT's feed was supplemented with 10 mg kg −1 H. roretzi tunics carotenoids extract. The result revealed that AT has the highest final weight (1119.2 ± 82.4 g) compare to those of C (881.0 ± 121.2 g) and CT (1068.2 ± 4.3 g). The specific growth rate (SGR) of AT (1.0 ± 0.07%/day) was significantly higher than C (0.7 ± 0.22%/day) and CT (0.7 ± 0.25%/day) while the feed conversion ratio (FCR) were 1.5 ± 0.6, 1.4 ± 0.6, and 1.2 ± 0.1 for C, CT and AT respectively. The hepatosomatic index (HSI) and Viscerosomatic index (VSI) of all groups showed no significant difference (p > 0.05). The muscle color was also positively affected by the treatments, CT and AT were significantly different from C (p < 005). The initial muscle color score was 1.7 ± 0.0 and the final scores were 3.4 ± 0.2, 5.6 ± 0.1, and 5.7 ± 0.0 for C, CT, and AT respectively. Moreover, muscle carotenoids content of AT (8.5 ± 0.2 mg kg −1 ) was significantly higher (p < 0.05) than those of CT (6.9 ± 0.3 mg kg −1 ) and C (6.1 ± 0.2 mg kg −1 ). Astaxanthin evidently is the most prominent carotenoid present in the muscle from all groups.

In a previous study, our research group demonstrated that sea cucumber (Apostichopus japonicus) extracts ameliorated allergic airway inflammation through CD4CD25Foxp3 T (regulatory T; Treg) cell activation and recruitment to the lung. In this study, we aimed to determine which components of sea cucumber contribute to the amelioration of airway inflammation. We used n-hexane fractionation to separate sea cucumber into three phases (n-hexane, alcohol, and solid) and evaluated the ability of each phase to elevate Il10 expression in splenocytes and ameliorate symptoms in mice with ovalbumin (OVA)/alum-induced asthma. Splenocytes treated with the n-hexane phase showed a significant increase in Il10 expression. In the n-hexane phase, 47 fatty acids were identified. Individual fatty acids that comprised at least 5% of the total fatty acids were 16:0, 16:1n-7, 18:0, 18:1n-7, 20:4n-6, and 20:5n-3 (eicosapentaenoic acid). After administering the n-hexane phase to mice with OVA/alum-induced asthma, their asthma symptoms were ameliorated. Several immunomodulatory effects were observed in the n-hexane phase-pretreated group, compared with a vehicle control group. First, eosinophil infiltration and goblet cell hyperplasia were significantly reduced around the airways. Second, the concentrations of Th2-related cytokines (IL-4, IL-5, and IL-13) and Th17-related cytokines (IL-17) were significantly decreased in the spleen and bronchoalveolar lavage fluid (BALF). Finally, the concentrations of TGF-β and IL-10, which are associated with Treg cells, were significantly increased in the BALF and splenocyte culture medium. In conclusion, a fatty acid-rich fraction (n-hexane phase) of sea cucumber extract ameliorated allergic airway inflammation in a mouse model.