Anti-Inflammatory and Antinociceptive Effects of Ethyl Acetate Fraction of an Edible Red Macroalgae Sarcodia ceylanica.

Research so far has only shown that edible red macroalgae, Sarcodia ceylanica has the ability to eliminate free radicals and anti-diabetic, anti-bacterial properties. This study was conducted both in vitro and in vivo on the ethyl acetate extract (PD1) of farmed red macroalgae in order to explore its anti-inflammatory properties. In order to study the in vitro anti-inflammatory effects of PD1, we used lipopolysaccharide (LPS) to induce inflammatory responses in murine macrophages. For evaluating the potential in vivo anti-inflammatory and antinociceptive effects of PD1, we used carrageenan-induced rat paw edema to produce inflammatory pain. The in vitro results indicated that PD1 inhibited the LPS-induced pro-inflammatory protein, inducible nitric oxide synthase (iNOS) in macrophages. Oral PD1 can reduce carrageenan-induced paw edema and inflammatory nociception. PD1 can significantly inhibit carrageenan-induced leukocyte infiltration, as well as the protein expression of inflammatory mediators (iNOS, interleukin-1ß, and myeloperoxidase) in inflammatory tissue. The above results indicated that PD1 has great potential to be turned into a functional food or used in the development of new anti-inflammatory and antinociceptive agents. The results from this study are expected to help scientists in the continued development of Sarcodia ceylanica for other biomedical applications.

Freeze-dried microalgae of Nannochloropsis oculata improve soybean oil's oxidative stability.

Marine microalga Nannochloropsis oculata possesses nutrients valuable for human health. In this study, we added freeze-dried N. oculata powder to soybean oil and observed a remarkable inhibition in oil oxidation. The amount of microalgae powder added was positively correlated to the increase in oil stability. The addition of 5.0 % (w/w) microalgae powder increased the oil stability index (OSI) values of soybean oil more than twofold at the tested temperatures 120 and 130 °C. N. oculata contains high levels of both phenolic compounds and α-tocopherols that could be the contributors to such an increase of the OSI. Two methods were conducted to assay the active ingredients released from microalgae: one employed three solvent systems to extract the microalgae and the other was the soybean oil added with microalgae. Analyses of free radical scavenging and reducing power suggested that the phenolic compounds dominated the antioxidation activities in soybean oil when it was infused with the microalgae powder. Our results suggest that N. oculata could potentially be used as an additive in cooking oil to increase the shelf life and nutritional value of the oil and to reduce the production of free radicals from lipid oxidation when the oil is used at high-temperature cooking processes.

Biogeochemical responses to the removal of maricultural structures from an eutrophic lagoon (Tapong Bay) in Taiwan.

The biogeochemistry of Tapong Bay, one of the major lagoons in southern Taiwan, was studied from 1999 to 2004, encompassing a period in 2003 in which aquaculture activities were terminated and the associated structures removed. Removal of the maricultural structures resulted in the reduction of the mean time for water exchange time in Tapong Bay from about 10+/-2d to 6+/-2d. The annual mean concentration of measured nutrients (DIN, DIP and DSi) also decreased significantly, likely due to improved water exchange, ceased feeding and increased biological utilization. An overall high primary production was maintained and likely to be constrained by temperature, light availability and turbidity rather than by abundant nutrients throughout the study period. The change in stoichiometric ratios among inorganic and organic nutrients (C/N, Si/N, N/P) may be attributed to the shift of plankton community between the two periods. The annual mean of Delta POC/Delta PON was 8.1, a little bit larger than that (7.3) before removal, also possibly resulting from the shift of planktonic community (from diatom-dominated to flagellate-dominated and increase of total phytoplankton and zooplankton) and removal of periphyton and oysters. The Tapong Bay shows a 37% increase (from 5.6 to 7.7 mol C m(-2)yr(-1)) in net ecosystem production (NEP) after structure removal, although the increase was not statistically significant. The change in environmental conditions has therefore influenced profoundly the carbon and nutrient biogeochemical processes and budgets in the semi-enclosed ecosystem.

Trophic structure and functioning in a eutrophic and poorly flushed lagoon in southwestern Taiwan.

Tapong Bay, a eutrophic and poorly flushed tropical lagoon, supports intensive oyster culture. Using the Ecopath approach and network analysis, a mass-balanced trophic model was constructed to analyze the structure and matter flows within the food web. The lagoon model is comprised of 18 compartments with the highest trophic level of 3.2 for piscivorous fish. The high pedigree index (0.82) reveals the model to be of high quality. The most-prominent living compartment in terms of matter flow and biomass in the lagoon is cultured oysters and bivalves, respectively. The mixed trophic impacts indicate that phytoplankton and periphyton are the most-influential living compartments in the lagoon. Comparative analyses with the eutrophic and well-flushed Chiku Lagoon and non-eutrophic tropical lagoons show that high nutrient loadings might stimulate the growth and accumulation of phytoplankton and periphyton and therefore support high fishery yields. However, net primary production, total biomass, fishery yields per unit area, and mean transfer efficiency of Tapong Bay were remarkably lower than those of Chiku Lagoon. The lower transfer efficiency likely results from the low mortality of cultured oysters and invasive bivalves from predation or the lower density of benthic feeders constrained by the hypoxic bottom water as a result of poor flushing. This might therefore result in a great proportion of flows to detritus. However, the hypoxic bottom water might further reduce the recycling of the entering detritus back into the food web. In contrast to many estuaries and tropical lagoons, poor flushing of this eutrophic tropical lagoon might induce a shift from detritivory to herbivory in the food web.

Vaccination of grouper broodfish (Epinephelus tukula) reduces the risk of vertical transmission by nervous necrosis virus.

Nervous necrosis virus (NNV) has caused mass mortality in many species of cultured fish at larval stage. Strong evidence of vertical transmission of NNV has been reported in the carrier broodstock of striped jack and sea bass. An effective immunization program was developed and monitored in adult groupers (Epinephelus coioides) with average body weight of 1.35kg. The highest neutralizing antibody titers were found in the fish intramuscularly injected with adjuvanted NNV vaccine at 10(9)TCID(50)kg(-1), and the enhanced 2-fold neutralization activity could sustain up to 17 months post-vaccination (mpv). An immunization program was applied in the broodstocks of grouper (Epinephelus tukula) with body weight of 35-60kg. The levels of NNV-specific antibodies detected, from 1 to 5 mpi, in the homogenates of the eggs from the vaccinated broodfish were elevated than that from non-vaccinated fish. By nested RT-PCR, NNV was detectable in the eggs from the non-vaccinated fish at Month 5, but not in the eggs from vaccinated fish. It is therefore suggested that vaccination will be a potentially practical measure to reduce the risk of vertical transmission of NNV of grouper broodfish under stress of repeated spawning.

Strategies to enhance cell growth and achieve high-level oil production of a Chlorella vulgaris isolate.

The autotrophic growth of an oil-rich indigenous microalgal isolate, identified as Chlorella vulgaris C--C, was promoted by using engineering strategies to obtain the microalgal oil for biodiesel synthesis. Illumination with a light/dark cycle of 14/10 (i.e., 14 h light-on and 10 h light-off) resulted in a high overall oil production rate (v(oil)) of 9.78 mg/L/day and a high electricity conversion efficiency (E(c)) of 23.7 mg cell/kw h. When using a NaHCO(3) concentration of 1,500 mg/L as carbon source, the v(oil) and E(c) were maximal at 100 mg/L/day and 128 mg/kw h, respectively. A Monod type model was used to describe the microalgal growth kinetics with an estimated maximum specific growth rate (mu(max)) of 0.605 day(-1) and a half saturation coefficient (K(s)) of 124.9 mg/L. An optimal nitrogen source (KNO(3)) concentration of 625 mg/L could further enhance the microalgal biomass and oil production, leading to a nearly 6.19 fold increase in v(oil) value.