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

OBJECTIVETo investigate the effect of docosahexaenoic acid (DHA) on invasiveness of aflatoxin B1 (AFB1)-induced hepatocellular carcinoma cells in vitro.

METHODSHepG2.2.15 cells were exposed to different concentrations of AFB1 and DHA plus AFB1. The cell migration and invasion were assessed using wound-healing and Transwell assay, and flow cytometry was used to analyze the cell cycle changes. The ultrastructural changes of the cells were observed by transmission electron microscopy.

RESULTSCompared with the control group, the cells exposed to2 µmol/L AFB1 showed obviously enhanced migration and invasion with decreased cell ratio in G1/G1 phase and increased cell ratio in G2/M phase but no changes in S phase cells; transmission electron microscopy revealed the presence of multiple nucleoli and significantly increased mitochondria and Golgi apparatus in the exposed cells. Compared with AFB1-exposed cells, the cells treated with DHA and AFB1 showed decreased migration and invasion abilities, and the G1/G1 phase cells increased and G2/M phase cells decreased significantly; ultrastructurally, the cells contained single nucleoli with decreased mitochondria and vacuolization occurred in the cytoplasm.

CONCLUSIONDHA can significantly inhibit AFB1-induced enhancement of cell migration and invasion in hepatocellular carcinoma cells in vitro.

Aflatoxin B1 ; pharmacology ; Carcinoma, Hepatocellular ; pathology ; Cell Cycle ; Cell Movement ; drug effects ; Docosahexaenoic Acids ; pharmacology ; Golgi Apparatus ; Hep G2 Cells ; Humans ; Liver Neoplasms ; pathology ; Mitochondria ; Neoplasm Invasiveness

OBJECTIVETo investigate the protective effects of docosahexaenoic acid (DHA) and nervonic acid (NA) on the learning and memory abilities in rats exposed to 1-bromopropane (1-BP) and their action mechanisms.

METHODSForty male Wistar rats (specific pathogen-free) were randomly divided into 4 groups (n = 10 for each), i.e., solvent control group, 1-BP (800 mg/kg) group, NA (150 mg/kg) + 1-BP (800 mg/kg) group, and DHA (500 mg/kg) + 1-BP (800 mg/kg) group. The rats were given respective test substances by gavage for 7 d. The Morris water maze (MWM) test was performed from days 8 to 12 to evaluate the rats' learning and memory abilities. After MWM test, rats were sacrificed in the next day, and cerebral cortex was quickly dissected and homogenized in an ice bath. The supernatant of the obtained homogenate was collected to measure the content of glutathione (GSH) and malondialdehyde (MDA) and the activities of glutathione reductase (GR) and γ-glutamate cysteine ligase (γ-GCL).

RESULTSThe MWM spatial navigation test showed that the 1-BP group had significantly longer escape latency and significantly longer total swimming distance compared with the control group (P<0.05), while the DHA+1-BP group had significant decreases in escape latency and total swimming distance compared with the 1-BP group (P<0.05). The spatial probe test showed that the number of platform crossings was significantly greater in the DHA+1-BP group and NA+1-BP group than in the 1-BP group (P<0.05); compared with the control group, the 1-BP group had a significantly lower ratio of time spent in the zone around the platform to total time (P < 0.05), and the ratio was significantly higher in the DHA+1-BP group than in the 1-BP group (P < 0.05). Compared with the control group, the 1-BP group had a 18.1% decrease in GSH content, and DHA could significantly reverse 1-BP-induced decrease in GSH content (P < 0.05). Compared with the 1-BP group, the DHA+1-BP group and NA+1-BP group had significantly decreased MDA content (P < 0.05), the DHA+1-BP group had significantly increased GR activity (P < 0.05), and the NA+1-BP group had significantly increased γ-GCL activity (P < 0.05).

CONCLUSIONThe rats exposed to 1-BP have oxidative stress in the brain and impaired cognitive function. DHA and NA can reduce 1-BP-induced cognitive function impairment in rats, possibly by increasing the activities of GR and γ-GCL and the content of GSH in the brain.

Animals ; Behavior, Animal ; Brain ; drug effects ; Docosahexaenoic Acids ; pharmacology ; Fatty Acids, Monounsaturated ; pharmacology ; Glutamate-Cysteine Ligase ; metabolism ; Glutathione ; metabolism ; Glutathione Reductase ; metabolism ; Hydrocarbons, Brominated ; toxicity ; Male ; Malondialdehyde ; metabolism ; Maze Learning ; drug effects ; Memory ; drug effects ; Oxidative Stress ; Rats ; Rats, Wistar

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*

The relationship between omega-3 polyunsaturated fatty acids (PUFAs) and violent-aggressive behavior has been payed attention since 1980s. Their correlation was explored by many epidemiological investigations, and the effect of PUFAs on prevention or reduction of violent-aggressive behavior in different groups were also affirmed by some intervention studies. This article summarized the previous studies and reviewed the history of epidemiological or intervention studies on PUFAs and its relationship with violent-aggressive behavior. It also presented the possible influencing factors in these studies and possible mechanisms.
Aggression ; Animals ; Dietary Fats, Unsaturated/pharmacology* ; Dietary Supplements ; Docosahexaenoic Acids/pharmacology* ; Eicosapentaenoic Acid/pharmacology* ; Fatty Acids, Omega-3/pharmacology* ; Fatty Acids, Omega-6/pharmacology* ; Fishes ; Folic Acid/metabolism* ; Humans ; Hydroxyindoleacetic Acid/metabolism* ; Norepinephrine/metabolism* ; Risk Factors ; Serotonin/metabolism* ; Violence/prevention & control*

OBJECTIVETo evaluate the effect of the combination of docosahexaenoic acid (DHA) and fluorouracil (FU) on human gastric carcinoma cell strain MGC803 in vitro.

METHODSThe influences of DHA and FU alone or in combination on cell proliferation was detected using MTT assay. Dose of median (Dm) of drugs (alone or in combination) and the combination index (CI) were calculated using the combination index equation of Chou-Talalay. Cell cycle were examined using flow cytometry. Cell apoptosis was determined by Annexin V-FITC/PI double staining method. The expression of apoptosis-related protein was detected using Western blot.

RESULTSDHA significantly inhibited the growth of MGC803, and low-dose DHA induced the proliferation of human embryonic lung fibroblast (P < 0.05). DHA remarkably strengthened the inhibitive effect of FU on the growth of MGC803, and decreased the Dm of FU by 3.6-2.5 folds (P < 0.05). When the inhibitory ratio reached 30%, the combination of DHA and FU showed synergism (CI < 1) and significant G(0)/G(1) arrest (vs FU, P < 0.05). DHA increased the apoptosis-inducing effect of FU and upregulated the cleaved-caspase-3 expression.

CONCLUSIONSDHA can inhibit the growth of MGC803. When combined with FU, DHA has synergetic effect in inhibiting the proliferation of gastric cancer cells and meanwhile decrease the dose of FU.

Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Cell Cycle ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Docosahexaenoic Acids ; pharmacology ; Drug Synergism ; Fluorouracil ; pharmacology ; Humans ; Stomach Neoplasms ; metabolism ; pathology

To investigate effects of docosahexaenoic acid (DHA) on proliferation and differentiation of rat adipocytes and to elucidate its potential mechanism, rat's primary preadipocytes in vitro were cultured. Treated adipocytes with 0 micromol/L (control group), 40 micromol/L (lower dose group) and 160 micromol/L (higher dose group) DHA. Cell living rations and proliferation were analyzed by trypan blue exclusion and MTT assay. The degree of adipogenesis and differentiation were measured by Oil Red O staining extraction assay and the expression of peroxisome proliferation activated receptor-gamma2 (PPARgamma2) mRNA were detected by reverse transcriptase-polymerase chain reaction (RT-PCR). It was demonstrated that cells living ration and the optical density (OD) of MTT were all decreased, especially treated by 160 micromol/L DHA at 60 (72 hours (P < 0.05). The OD of Oil Red O staining and the expression of PPARgamma2 mRNA were all decreased after treated by 160 micromol/L DHA (P < 0.01). It can be concluded that DHA can inhibite proliferation and differentiation of adipocytes in some degree. Higher dose of DHA can markedly decrease adipogenesis and prevent differentiation of adipocytes, which may be in part associated with its effect on decreasing the expression of PPARgamma2 mRNA.
Adipocytes ; cytology ; drug effects ; Animals ; Cell Differentiation ; drug effects ; Cell Proliferation ; drug effects ; Cells, Cultured ; Docosahexaenoic Acids ; pharmacology ; Dose-Response Relationship, Drug ; Male ; PPAR gamma ; metabolism ; RNA, Messenger ; metabolism ; Rats ; Rats, Sprague-Dawley

BACKGROUNDCigarette smoke induced airway inflammation plays a role in pathogenesis of airway inflammation. Resolvin-D1 derived from omega-3 polyunsaturated fatty acids is an endogenous anti-inflammatory and proresolving lipid mediator. Resolvin-D1 ameliorated inflammatory responses in lung injury, asthma, peritonitis and atherosclerosis. We investigated whether resolvin-D1 suppressed the productions of chemokines and oxidative stress induced by cigarette smoke extract (CSE) in vitro and its possible mechanism.

METHODSWe examined the proinflammatory chemokine interleukin-8 and hydrogen peroxide (H2O2) productions induced by CSE in 16 human bronchial epithelial (16HBE) cells after resolvin-D1 treatment and their mechanisms. 16HBE cells were treated with resolvin-D1 at up to 10 nmol/L, for 30 minutes before CSE up to 16% (v/v) exposure. Release of interlukin-8 proteins was assessed by enzyme linked immunosort assay (ELISA) and its mRNA level by RT-PCR. We evaluated extracellular H2O2 expression in the supernatant. Phosphorylation of NF-κB/p65 and degradation of I-κB in 16HBE cells were determined by Western blotting analysis and NF-κB DNA binding activity by electrophoretic mobility shift assay (EMSA).

RESULTS16HBE cells treated with 8% CSE showed significantly higher interlukin-8 production. Resolvin-D1 pretreatment inhibited CSE induced interlukin-8 production (mRNA and protein) in a dose and time dependent manner. Extracellular H2O2 level decreased after resolvin-D1 treatment. Resolvin-D1 attenuated CSE triggered I-κB degradation and NF-κB/p65 activation dose dependently and inhibited NF-κB DNA binding activity.

CONCLUSIONResolvin-D1 inhibits CSE induced interlukin-8 and H2O2 production in 16HBE cells by modulating NF-κB activation and has therapeutic potential for pulmonary inflammation.

Blotting, Western ; Cell Line ; Cell Survival ; drug effects ; Docosahexaenoic Acids ; pharmacology ; Electrophoretic Mobility Shift Assay ; Enzyme-Linked Immunosorbent Assay ; Humans ; Hydrogen Peroxide ; metabolism ; Interleukin-8 ; metabolism ; NF-kappa B ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Smoking ; adverse effects

Objective: To investigate the effects of docosahexenoic acid (DHA) supplementation on infant's growth and BMI during pregnancy. Methods: A total of 1 516 healthy pregnant women delivered their babies in two maternal and child health care hospitals in Beijing and were chosen as the subjects in this cohort study from May to October 2015. Self-developed questionnaires were used to gather general information of the subjects, including age, height, weight, weight gain during pregnancy, delivery mode, DHA supplementation etc., before giving birth. Information on body length, weight, head circumference and BMI at birth and 6 months postnatal, of the infants were recorded. Breast milk was collected to test the fatty acid profiles by using the gas chromatography (GC) method at one to three months postnatally. Results: The overall rate of DHA supplementation was 47.76% among the pregnant women, in which introduction of DHA from the early and second stage of the pregnancy accounted for 49.31% and 39.64% respectively. When DHA supplementation began from the early pregnant stage, the DHA concentration showed an increase in the milk (P<0.05), whereas the supplementation began from the second and third stages did not affect the milk DHA concentration (P>0.05). Higher height and lower BMI were seen in the infants at birth and 6 months in the supplementation group when comparing to the non-supplementary group (P<0.05), with the greatest effects noticed in the earliest supplementation group. Specifically, the head circumference appeared larger from the early pregnant stage in the DHA supplementary group, than that in the non-supplement group (P=0.001). The increment of head circumference was larger than that in the other groups when the infants were 6-month old (P<0.01). Results from the partial regression analysis showed that during pregnancy, there were positive correlations between DHA supplementation and height (r=0.324, r=0.216), head circumference (r=0.221, r=0.302) as well as the increment of head circumference (r=0.276) at birth and 6 months (P<0.05). Whereas, a negative correlation was shown between DHA and the infants' BMI (r=-0.310, r=-0.371) (P<0.05) when supplementation was given during maternal pregnancy. Conclusions: When DHA supplementation program was carried out during maternal pregnancy, it could increase the height and head circumference and inhibit the rapid increase of BMI in the infants BMI. Our findings seemed helpful in promoting brain development and preventing the childhood obesity.
Body Height ; Body Mass Index ; Body Weight ; Child Development/drug effects* ; Cohort Studies ; Dietary Supplements ; Docosahexaenoic Acids/pharmacology* ; Female ; Humans ; Infant ; Infant, Newborn/physiology* ; Maternal-Fetal Exchange ; Parturition ; Pregnancy ; Pregnancy Outcome ; Prenatal Care ; Weight Gain

OBJECTIVETo investigate the mechanism of enhanced large conductance calcium-activated potassium channel currents (BK) in coronary smooth muscle cells (SMCs) by docosahexaenoic acid (DHA).

METHODSCoronary SMCs were isolated by enzyme digestion. Potassium channels in coronary SMCs were identified by applications of different potassium blockers. Effects of DHA and its metabolite 16, 17-epoxydocosapentaenoic acid (16, 17-EDP) on BK channels in the absence and presence of cytochrome P450 epoxygenase inhibitor SKF525A were studied by patch clamp in whole-cell configuration.

RESULTSBK channels were widely distributed in SMCs, and BK currents in normal SMCs accounted for (64.2 ± 2.7)% of total potassium currents (n = 20). DHA could activate BK channels, and its 50% effective concentration (EC(50)) was (0.23 ± 0.03) µmol/L, however, the effect of DHA on BK channels was abolished after SMCs were incubated with cytochrome P450 epoxygenase inhibitor SKF525A. 16, 17-EDP, a metabolite of DHA, could reproduce the effects of DHA on BK channels, and its EC(50) was (19.7 ± 2.8) nmol/L.

CONCLUSIONDHA and metabolites can activate BK channels and dilate coronary arteries through activating cytochrome P450 epoxygenase pathway.

Animals ; Coronary Vessels ; cytology ; drug effects ; metabolism ; Cytochrome P-450 Enzyme Inhibitors ; Docosahexaenoic Acids ; pharmacology ; Fatty Acids, Unsaturated ; pharmacology ; Large-Conductance Calcium-Activated Potassium Channels ; metabolism ; Muscle, Smooth, Vascular ; drug effects ; metabolism ; Myocytes, Smooth Muscle ; drug effects ; metabolism ; Proadifen ; pharmacology ; Rats ; Rats, Sprague-Dawley