Nitrogen source is one of the important factors that affect the microalgae growth and lipid accumulation. We studied the effects of various nitrogen sources (i.e. NaNO3, CO(NH2)2, NH4Cl and CH3COONH4) and amount on the growth density, lipid yield, and eicosapentaenoic acid (EPA) content of Nannochloropsis oculata by single factor experimental method. The results show that N. oculata preferred NH4+ as nitrogen source rather than NO3- and CO(NH2)2. NH4+ could promote the growth and lipid accumulation of N. oculata. With the increase of nitrogen concentration, the biomass and the content of polyunsaturated fatty acid (PUFA) increased, but the content of lipid decreased. CH3COONH4 was the most suitable for growth, accumulation of lipid and EPA of N. oculata among the four investigated nitrogen sources. The optimal concentration was 5.29 mmol/L.
Eicosapentaenoic Acid ; metabolism ; Lipids ; biosynthesis ; isolation & purification ; Microalgae ; growth & development ; metabolism ; Nitrogen ; analysis ; metabolism ; Stramenopiles ; growth & development ; metabolism

Interests on the effects of cytochrome P450 (CYP450) monooxygenases and epoxyeicosatrienoic acids (EETs) on myocardial ischemic-reperfusion injury has been increased in recent years. The CYP450/EET system may influence the degree of myocardial ischemic-reperfusion injury through "poly-targets", such us oxygen free radical, calcium overload, leukocytes adherence, nitric oxide, ATP-sensitive K+ channels, and mitogen activated protein kinase. The exaggeration or recovery of injury depends on the physical status. Study of factors that affects CYP450/EET, particularly identification of their involvement in cardioprotective signaling and specific roles, will elucidate the mechanisms of myocardial ischemic-reperfusion injury, and find a new way of prevention and treatment. This article will review the relationship between the changes of CYP450/EETs system and myocardial ischemic-reper-
Animals ; Cytochrome P-450 Enzyme System ; metabolism ; Eicosapentaenoic Acid ; metabolism ; Humans ; Mixed Function Oxygenases ; metabolism ; Myocardial Reperfusion Injury ; etiology ; metabolism

Compared with cultured fish, the fish oil of ocean wild fish contains much more Eicosapntemacnioc acid (EPA), Docosahexenoic acid (DHA), fat-soluble vitamin. To improve the utility value of oacean wild fish, small hairtail was used as raw material to investigate the technology of extracting fish oil with enzyme. The variables to affect the efficiency of extraction, extracting and centrifugation were selected as temperature, reaction time and pH value. Optimal technology conditions were determined by the response surface method: The liquid/solid ratio is 6, pH 7.3, enzyme amount of 1000 u/g raw material, agitation speed of 200 r/min, enzymolysis under 45 degrees C for 90 min. The optimum extraction conditions were as follows: 100 mL extractant (every 20 g surimi), pH4.0, extracted under 40 degrees C for 25 min. The optimal centrifuge conditions were: centrifuge speed of 3000 r/min (1865 g), centrifuged for 10 min. The oil extraction efficiency was 79.9%. This study developed the traditional technology of fish oil extraction, and improved the protection of the active components.
Animals ; Docosahexaenoic Acids ; analysis ; Eicosapentaenoic Acid ; analysis ; Enzymes ; metabolism ; Fish Oils ; isolation & purification ; Fishes ; metabolism ; Oceans and Seas ; Technology, Pharmaceutical ; methods

The diatom Nitzschia laevis is a good alternative source of eicosapentaenoic acid (EPA). Besides strategies for high cell density culture, EPA productivity may be further improved by herbicides. The effect of the herbicide quizalofop-p-ethyl on the growth and EPA production was studied in this paper. As the solvent of the herbicide, DMSO was proved to inhibit the growth and EPA production of N. laevis. The concentration of DMSO in the medium should not exceed 0.2%. Quizalofop-p-ethyl could cause morphology damage to the N. laevis cells. With the increasing concentration of quizalofop-p-ethyl from 0 mmol/L to 0.4 mmol/L, the dry cell weight production decreased, while at the same time, the lipid content of the dry cell mass increased. When treated with 0.1 mmol/L quizalofop-p-ethyl, the EPA content increased from 3.00% to 3.58% (of dry cell weight, DW), and the proportion of EPA (20:5) in total fatty acids (TFA) increased from 25.15% to 32.88% . These results indicated that the herbicide quizalofop-p-ethyl could stimulate the accumulation of EPA; therefore it might be useful for selecting algae colonies that overproduce EPA.
Culture Media ; Culture Techniques ; Diatoms ; growth & development ; metabolism ; Eicosapentaenoic Acid ; biosynthesis ; Herbicides ; pharmacology ; Propionates ; pharmacology ; Quinoxalines ; pharmacology

This study was carried out in adult ferret cardiomyocytes to investigate the effects of the n-3 polyunsaturated fatty acids (PUFAs) on voltage-gated K(+) currents. We report that the two outward K(+) currents: the transient outward K(+) current (I(to)) and the delayed rectifier K(+) current (I(K)), are both inhibited by the n-3 PUFAs, while the inwardly rectifying K(+) current (I(K1)) is unaffected by the n-3 PUFAs. Docosahexaenoic acid (C22:6n-3, DHA) produced a concentration dependent suppression of I(to) and I(K) in adult ferret cardiomyocytes with an IC(50) of 7.5 and 20 micromol/L, respectively; but not I(K1). In addition, eicosapentaenoic acid (C20:5n-3, EPA) had the effects on the three K(+) channels similar to DHA. Arachidonic acid (C20:4n-6, AA) at 5 or 10 micromol/L, after an initial inhibitory effect on I(K), caused an activation of I(K),AA which was prevented by pretreatment with indomethacin, a cyclooxygenase inhibitor. Monounsaturated and saturated fatty acids, which are not antiarrhythmic, lack the effects on these K(+) currents. Our results demonstrate that the n-3 PUFAs inhibit cardiac I(to) and I(K) with much less potency compared to their effects on cardiac Na(+) and Ca(2+) currents as we reported previously. This inhibition of the cardiac ion currents by the n-3 PUFAs may contribute to their antiarrhythmic actions.
Animals ; Arachidonic Acid ; pharmacology ; Docosahexaenoic Acids ; pharmacology ; Dose-Response Relationship, Drug ; Eicosapentaenoic Acid ; pharmacology ; Ferrets ; Myocytes, Cardiac ; drug effects ; metabolism ; Potassium Channels, Voltage-Gated ; metabolism

Three long-chain polyunsaturated fatty acids, docosahexaenoic acid (DHA, 22:6n-3), eicosapentaenoic acid (EPA, 20:5n-3) and arachidonic acid (ARA, 20:4n-6), are the most biologically active polyunsaturated fatty acids in the body. They are important in developing and maintaining the brain function, and in preventing and treating many diseases such as cardiovascular disease, inflammation and cancer. Although mammals can biosynthesize these long-chain polyunsaturated fatty acids, the efficiency is very low and dietary intake is needed to meet the requirement. In this study, a multiple-genes expression vector carrying mammalian A6/A5 fatty acid desaturases and multiple-genes expression vector carrying mammalian Δ6/Δ5 fatty acid desaturases and Δ6/Δ5 fatty acid elongases coding genes was used to transfect HEK293T cells, then the overexpression of the target genes was detected. GC-MS analysis shows that the biosynthesis efficiency and level of DHA, EPA and ARA were significantly increased in cells transfected with the multiple-genes expression vector. Particularly, DHA level in these cells was 2.5 times higher than in the control cells. This study indicates mammal possess a certain mechanism for suppression of high level of biosynthesis of long chain polyunsaturated fatty acids, and the overexpression of Δ6/Δ5 fatty acid desaturases and Δ6/Δ5 fatty acid elongases broke this suppression mechanism so that the level of DHA, EPA and ARA was significantly increased. This study also provides a basis for potential applications of this gene construct in transgenic animal to produce high level of these long-chain polyunsaturated fatty acid.
Acetyltransferases ; genetics ; metabolism ; Arachidonic Acid ; biosynthesis ; Docosahexaenoic Acids ; biosynthesis ; Eicosapentaenoic Acid ; biosynthesis ; Fatty Acid Desaturases ; genetics ; metabolism ; Fatty Acid Synthases ; genetics ; metabolism ; Fatty Acids, Unsaturated ; biosynthesis ; Genetic Vectors ; HEK293 Cells ; Humans ; Transfection

OBJECTIVETo investigate whether Resolvin E1 (RvE1) could protect against ox-LDL-induced injury on human vein vascular endothelial cells and reveal related molecular mechanisms.

METHODSHuman vein vascular endothelial cells were randomly assigned to six groups, which were treated with saline, RvE1, wortmanin, ox-LDL, ox-LDL and RvE1, ox-LDL and RvE1 and wortmanin, respectively. After 48 h, survival rates were determined by MTT, apoptosis rate of cells were determined by flow cytometry, TNF-α contents were assayed by ELISA, caspase 3 and 9 activities were measured by microplate reader, and the expression of p-AKT and LOX-1 were determined by Western blot.

RESULTCompared with normal saline group, survival rate was markedly decreased and apoptosis rate, TNF-α content, caspase 3 and 9 activities, and the expression of LOX-1 were significantly increased in ox-LDL group (P < 0.01). Survival rate was significantly increased and apoptosis rate, TNF-α content, caspase 3 and 9 activities, and the expression of LOX-1 were significantly decreased in ox-LDL + RvE1 group compared to ox-LDL group (P < 0.01), these beneficial effects of RvE1 could be blocked by PI3K inhibitor wortmanin (P < 0.05).

CONCLUSIONThe present data showed that RvE1 could effectively protect against ox-LDL-induced endothelial cell injury, which might be mediated by PI3K-AKT signaling pathway.

Apoptosis ; drug effects ; Cells, Cultured ; Eicosapentaenoic Acid ; analogs & derivatives ; pharmacology ; Endothelial Cells ; drug effects ; metabolism ; Humans ; Lipoproteins, LDL ; adverse effects ; Signal Transduction ; Umbilical Veins ; cytology

OBJECTIVE: To explore the correlation between the eicosapentaenoic acid(EPA), docosahexaenoic acid (DHA) and the aggressive behavior in mice. METHODS: Seventy-two male Kunming mice were divided into control group, fish oil group, simvastatin group and aggressive reference group randomly. The control group, fish oil group and simvastatin group were given normal saline, fish oil and simvastatin by irrigation respectively for 3 months consecutively, each mouse was raised isolatedly. The latent period of assault, the frequencies of tail swing and assault, and the cumulative time of assault were recorded at the beginning and the end of the intervention. Finally, the EPA and DHA in brain were analyzed by gas chromatography-mass spectrometry (GC-MS). The aggressive reference group was raised without intervention and was evaluated as aggressive reference only. RESULTS: (1) Before intervention, the latent period of assault, the frequencies of tail swing, the frequencies of assault, and the cumulative time of assault were not significantly different from each other group. After intervention, the differences were significant (P<0.05). (2) After the intervention, the content of EPA and DHA in mice brain was the most in the fish oil group, and the least in the simvastatin group. (3) The content of EPA was negatively related with the four indexes (P<0.05) before and after the intervention. The content of DHA was negatively related with the frequencies of tail swing and assault (P<0.05). CONCLUSION There is a correlation between the EPA, DHA and aggressive behavior in mice under stress.
Aggression/physiology* ; Animals ; Behavior, Animal/physiology* ; Brain/metabolism* ; Docosahexaenoic Acids/metabolism* ; Eicosapentaenoic Acid/metabolism* ; Fatty Acids, Omega-3/metabolism* ; Fish Oils/pharmacology* ; Gas Chromatography-Mass Spectrometry ; Male ; Mice ; Random Allocation ; Simvastatin/pharmacology*

OBJECTIVETo observe the influence of either alone or combined mixed-tocopherols combined with eicosapentaenoic acid (EPA) and α-Tocopherol use on oxidized LDL (oxLDL) induced 8-hydroxy-2'-deoxyguanosine (8-OHDG) and interleukin-6 (IL-6) secretion by human umbilical vein endothelial cells (HUVECs) and to explore the potential mechanism.

METHODCultured HUVECs in vitro were incubated with oxLDL, oxLDL + α-tocopherol, oxLDL + mixed-tocopherols, oxLDL + EPA, oxLDL + α-tocopherol + EPA, oxLDL + mixed-tocopherols + EPA for 24 hours, respectively. Secretion of 8-OHDG and IL-6 were detected by cell enzyme linked immunosorbent assay (ELISA). The expressions of superoxide dismutase (SOD), protein kinase C-δ (PKC-δ), phosphorylated PKC-δ (p-PKC-δ) were analyzed by Western blot.

RESULTS8-OHDG and IL-6 secretion of HUVECs was significantly increased significantly after incubated with oxLDL for 24 hours which could be significantly attenuated in the presence of tocopherols and EPA (alone or in combination, all P < 0.05) while the strongest inhibition effects were seen with combined use of mixed-tocopherols and EPA. Moreover, combination of mixed-tocopherols and EPA could also significantly increase SOD activity and decrease PKC activity (all P < 0.05). However, the protein expression of SOD and PKC-was similar among groups.

CONCLUSIONCombined mixed-tocopherols + EPA use enhanced the inhibiting effects on the secretion of 8-OHDG and IL-6 in oxLDL stimulated HUVECs which might be linked with increased SOD activity and reduced p-PKC activity.

Antioxidants ; Cells, Cultured ; Deoxyguanosine ; analogs & derivatives ; secretion ; Eicosapentaenoic Acid ; pharmacology ; Human Umbilical Vein Endothelial Cells ; drug effects ; metabolism ; Humans ; Interleukin-6 ; secretion ; Lipoproteins, LDL ; adverse effects ; Protein Kinase C ; metabolism ; Superoxide Dismutase ; metabolism ; alpha-Tocopherol ; pharmacology

OBJECTIVETo investigate the change in the expression of tight junction protein ZO-1 in intestinal epithelial cells (Caco-2 cells) and the protective effect of eicosapentaenoic acid (EPA) after adherent-invasive Escherichia coli (E.coli) LF82 infection.

METHODSThe Caco-2 cell line was used to establish an in vitro model of tight junction of intestinal epithelial cells. Caco-2 cells were divided into EPA treatment groups (0, 25, 50, 100, and 200 μmol/L EPA) and EPA (0, 25, 50, 100, and 200 μmol/L EPA)+E.coli LF82 treatment (0, 6, and 12 hours) groups. A microscope was used to observe the morphological characteristics of the cells. MTT assay was used to determine the cell growth curve. The activity of alkaline phosphatase (ALP) at both sides of the cell membrane was compared to evaluate the Caco-2 cell model. MTT assay and flow cytometry were used to investigate the effects of different concentrations of EPA on the survival rate and apoptosis rate of Caco-2 cells. RT-qPCR was used to measure the mRNA expression of ZO-1 in Caco-2 cells after EPA and/or E.coli LF82 treatment. ELISA was used to measure the change in the level of tumor necrosis factor-α (TNF-α) in culture supernatant.

RESULTSAfter EPA treatment (25 and 50 μmol/L), the proliferation of Caco-2 cells was induced in a dose-dependent manner. The survival rates of the cells were significantly higher than those in the control group (P<0.05). The EPA treatment (100 and 200 μmol/L) groups had a significant inhibitory effect on the proliferation of Caco-2 cells in a dose-dependent manner. The survival rates of the cells were significantly lower than those in the control group (P<0.05). The EPA treatment (100 and 200 μmol/L) groups had a significant increase in cell apoptosis rate compared with the control group (P<0.05). The 6- and 12-hour E.coli LF82 treatment groups had decreasing mRNA expression of ZO-1 in Caco-2 cells over the time of treatment and had significantly lower mRNA expression of ZO-1 than the untreated group (P<0.05). The Caco-2 cells treated with E.coli LF82 and 25 or 50 μmol/L EPA for 6 or 12 hours showed an increase in the mRNA expression of ZO-1 with the increasing concentration of EPA, as well as significantly higher mRNA expression of ZO-1 than the Caco-2 cells treated with E.coli LF82 alone (P<0.05). The Caco-2 cells treated with E.coli LF82 alone for 6 or 12 hours had increasing secretion of TNF-α over the time of treatment and had significantly higher secretion than the untreated Caco-2 cells (P<0.05). The Caco-2 cells treated with E.coli LF82 and 25 or 50 μmol/L EPA for 6 or 12 hours showed a reduction in the secretion of TNF-α with the increasing concentration of EPA and had significantly lower secretion than the Caco-2 cells treated with E.coli LF82 alone (P<0.05).

CONCLUSIONSEPA can effectively prevent the destruction of tight junction of intestinal epithelial cells induced by E.coli LF82 infection and inhibit the secretion of inflammatory factors. Therefore, it has a certain protective effect on intestinal mucosal barrier.

Apoptosis ; drug effects ; Caco-2 Cells ; Eicosapentaenoic Acid ; pharmacology ; Escherichia coli ; pathogenicity ; Humans ; Intestinal Mucosa ; metabolism ; microbiology ; RNA, Messenger ; analysis ; Tight Junctions ; drug effects ; Tumor Necrosis Factor-alpha ; secretion ; Zonula Occludens-1 Protein ; genetics