Novel Lipase from Golden Pompano(Trachinotus ovatus)Viscera:Purification,Characterization,and Application in the Concentrating of n-3 Polyunsaturated Fatty Acids

Lipases have been widely applied in a variety of industrial fields,such as food,pharmaceuticals,biofuels,and biotechnology.Recent years have witnessed a great interest in modifying lipids for the production of triacylglycerols enriched with n-3 polyunsaturated fatty acids(PUFAs).Here,a novel salt-tolerant,organic solvent-stable,and bile salt-activated lipase was purified from golden pompano(Trachinotus ovatus)viscera,which was named as golden pompano lipase(GPL).GPL had a specific activity of 57.2U mg^(-1)with an estimated molecular weight of 14 k Da,exhibited optimal activity at 40℃a nd pH 8.0,and showed K_(m)and V_(max)of 40.16μmol L^(-1)and 769.23μmol L^(-1)min^(-1),respectively.GPL activity was enhanced by Mn^(2+)and sodium deoxycholate.It was active in organic solvents,including methanol,ethanol,chloroform,and hexane.GPL also showed a good salinity tolerance of up to 1 mol L^(-1).n-3PUFA enrichment in the glyceride fraction of golden pompano oil was performed by GPL-catalyzed hydrolysis and yielded a total PUFA concentration of 56.99%.EPA,DHA,and DPA were enriched by 10.4-,3.2-,and 1.8-fold of their initial levels,respectively.This study recognized the industrial applicability of GPL to prepare enriched C_(20-22)n-3 PUFA.

Different n-6/n-3 polyunsaturated fatty acid ratios affect postprandial metabolism in normal and hypertriglyceridemic rats

Postprandial metabolism plays major roles in many pathological conditions.The n-6/n-3 polyunsaturated fatty acid(PUFA)ratio is closely related to various physiological disorders.This study aimed to investigate the effects of high fat meals with different n-6/n-3 PUFA ratios on postprandial metabolism in normal control(NC)and hypertriglyceridemia(HTG)rats.The postprandial response of triglyceride(TG)in HTG groups was higher than that in NC groups after different n-6/n-3 PUFA ratio meals.The HTG groups showed higher postprandial total cholesterol(TC)responses than NC groups after 1:1 and 20:1 ratio meals.The 5:1 n-6/n-3 PUFA ratio elicited lower postprandial responses of tumor necrosis factorα(TNF-α)than 1:1 and 10:1 ratios in HTG groups.The postprandial malondialdehyde(MDA)response was lower after a 5:1 n-6/n-3 PUFA ratio meal than 1:1 and 20:1 ratio meals in HTG groups.The 1:1 ratio resulted in a lower postprandial reactive oxygen species(ROS)level than 5:1 and 10:1 n-6/n-3 PUFA ratios in NC groups.The results showed that a low n-6/n-3 PUFA ratio improved postprandial dysmetabolism induced by a high fat meal in NC and HTG rats.A high n-6/n-3 PUFA ratio increased the difference in postprandial metabolism between NC and HTG rats.

Anti-inflammatory and Immunomodulatory Effects of Marine n-3 Polyunsaturated Fatty Acids on Human Health and Diseases

The pharmaceutical effects of n-3 polyunsaturated fatty acids(n-3 PUFAs) as dietary nutrients on human health and diseases have gained much attention and are investigated for decades. Docosahexaenoic acid(DHA), eicosapentaenoic acid(EPA) and docosapentaenoic acid(DPA) are the three major n-3 PUFAs enriched in marine organisms, such as fish, shrimp, algae, and so on. It has been well known that n-3 PUFAs, especially DHA and EPA, are beneficial in reducing the risk of cardiovascular and cerebrovascular diseases. Accumulating evidence suggests that n-3 PUFAs might cure inflammatory diseases through several mechanisms, such as plasma membrane remodeling of lymphocytes, down-regulating pro-inflammatory cytokines, and alternating adhesion molecule expressions. Several molecular targets of n-3 PUFAs on immune-regulation have also been identified, such as GPR120(FFA4), protein kinase C(PKC), and PPAR-γ. However, it remains inconclusive if dietary n-3 PUFAs function the same both in vitro and in vivo based on cohort studies. This review will focus on the molecular targets and mechanisms of anti-inflammatory and immunomodulatory effects of n-3 PUFAs on human health and diseases, such as obesity, tumor, diabetes, and autoimmune diseases.

Effects of dietary ratio of n-6 to n-3 polyunsaturated fatty acids on immunoglobulins, cytokines, fatty acid composition, and performance of lactating sows and suckling piglets

This experiment was conducted to investigate the effects of dietary ratios of n-6：n-3 polyunsaturated fatty acids （PUFA） on the performance of lactating sows and their piglets. Thirty pregnant Landrace sows were assigned to one of three treatments from d 108 of gestation until weaning （26-29 d） and were fed diets containing different ratios of n-6：n-3 PUFA including 3：1,9：1 and 13：1. The effects on sow and litter production traits were examined together with an assessment of sow body condition. No differences were detected among the treatments for the daily feed intake of sows or changes in sow weight and back-fat levels during lactation （P 〉 0.05）. Litter size at d 14 and d 21 were tended to increase in 3：1 treatment compared with 9：1 and 13：1 treatments （P 〈 0.10）. Litter weight gain （1.77 kg/d） from d 0 to d 14 was tended to increase in 9：1 groups compared with the other two treatments （P 〈 0.10）. A significant difference was observed for the content of a -linolenic acid, total n-3 PUFA, and the ratio of n-6：n-3 PUFA in the colostrum, milk, and piglets plasma （P 〈 0.01）. The effects of different ratios of n-6：n-3 PUFA in sow diets on colostrum, milk and piglet plasma immunoglobulin concentrations are studied. No difference was observed among treatments in the concentrations of IgM, and IgA in colostrum （P 〉 0.05）. A great significant difference for IgG concentration was observed among 3 group in colostrum. A great significant difference for IgA, and IgM （P〈 0.01） concentrations in piglet plasma at d14 and a significant difference for IgG（P 〈 0.05） was observed at d14. Furthermore, at d 21 of lactation, piglet plasma IgG and IgA concentration were greater in 3：1 compared with 13：1 group （P 〈 0.01）. In summary, the current study demonstrated that altering the ratio of n-6：n-3 PUFA in lactating sow diet had an effect on the immune component including immunoglobulin and cytokines, and it tended to increase the litter average daily gain and improve the immune status of piglets when dietary ratio of n-6：n-3 PUFA was 9：1.

Recent advances in liver preconditioning: Thyroid hormone, n-3 long-chain polyunsaturated fatty acids and iron

Liver preconditioning (PC), defined as an enhanced tolerance to injuring stimuli induced by previous specific maneuvers triggering beneficial functional and molecular changes, is of crucial importance in human liver transplantation and major hepatic resection. For these reasons, numerous PC strategies have been evaluated in experimental models of ischemia-reperfusion liver injury, which have not been transferred to clinical application due to side effects, toxicity and difficulties in implementation, with the exception of the controversial ischemic PC. In recent years, our group has undertaken the assessment of alternate experimental liver PC protocols that might have application in the clinical setting. These include thyroid hormone (T3), n-3 long-chain polyunsaturated fatty acids (n-3 LCPUFA), or iron, which suppressed liver damage due to the 1 h ischemia-20 h reperfusion protocol. T3, n-3 LCPUFA and iron are hormetic agents that trigger biologically beneficial effects in the low-dose range, whose multifactorial mechanisms of action are discussed in the work.

Effects of the Ratio of n-6∶n-3 Polyunsaturated Fatty Acids in the Maternal Diet on Immunoglobulins,Fatty Acid Composition,and Performance of Lactating Sows and Suckling Piglets under Conditions of Low Maternal Energy Intake

This experiment was conducted to investigate the effects of different ratios of n-6 ∶ n-3 polyunsaturated fatty acids （PUFA） in sow diets on the performance of lactating sows and their piglets at low digestible energy intakes. Twenty-one pregnant Landrace sows were assigned to one of three diets from day 108 of gestation until weaning （26 to 29 d） ,containing n-6∶n-3 PUFA ratios of 3 ∶1,8 ∶1 and 11 ∶1. The effects on sow and litter production traits and on sow body condition were examined. There were no differences among treatments in daily feed intakes or in changes in sow weight and back-fat levels during lactation. Litter size,litter weight at birth and weaning and litter average daily weight gain were also unaffected by treatment. As expected, large differences were observed in n-6 and n-3 fatty acids in the colostrum and plasma of sows and piglets （P 〈 0. 01） . The ratio of n6 ∶ n-3 PUFA the diet was positively correlated with those in colostrum,sow plasma and piglet plasma （R 2= 0. 55,0. 80 and 0. 80,respectively） . Sow plasma insulin and IGF-I levels at weaning were unaffected by the treatments. Plasma leptin （P 〈 0. 05） concentrations were increased in sows fed the diet with a n-6∶n-3 ratio of 8 ∶ 1. Immunoglobulin concentrations in colostrum were not altered by dietary treatment. Plasma IgG concentrations at d 14 were highest in piglets from sows fed the 8 ∶ 1 ratio of n-6∶n-3. Furthermore,this group had the highest IgA concentrations at day 21 of lactation compared with the other two groups （P 〈 0. 05） . In summary,our study demonstrated that at low digestible energy levels,altering the ratio of n-6 ∶ n-3 PUFA in the diets for lactating sows affected immune components and the fatty acid composition of lactating sows and their piglets. Further studies are needed to examine whether higher levels of fat supplementation than those used in the present study （1. 5%） can successfully enhance performance.

The Efficacy of the Consumption of n-3 Polyunsaturated Fatty Acids for the Maintenance of Remission in Patients with Inflammatory Bowel Disease

The aim of the present study was to investigate the efficacy of the actual consuming n-3 PUFA for remission-maintenance in IBD patients. A questionnaire on the dietary habits of patients one month before hospitalization (Q1) was completed by 24 patients with IBD (10 ulcerative colitis (UC) subjects and 14 Crohn’s disease (CD) subjects) treated at our hospital. We educated the study subjects about an n-3 PUFA diet, and a follow-up survey (Q2) was conducted 6 to 12 months after discharge. Disease activity was evaluated using the International Organization for the Study of Inflammatory Bowel Disease (IOIBD) score and/or the Crohn’s Disease Activity Index (CDAI) score for CD and the partial UCDAI score without endoscopic evaluation for UC. Q1 showed that the average n-3 and n-6 PUFA intakes were 1673 ± 1651 mg and 9146 ± 5217 mg, respectively, and the average n-3/n-6 ratio was 0.27 ± 0.31. In Q2, the intake of n-3 PUFA was significantly higher (3671 ± 1684 mg, p < 0.001), whereas the n-6 PUFA intake decreased significantly (5217 ± 1973 mg, p < 0.001) compared to those in Q1. As a consequence, the dietary n-3/ n-6 ratio was significantly increased (0.87 ± 0.60, p < 0.001). Maintenance of the remission rate was significantly higher in IBD patients who complied with the n-3 diet, and these patients maintained a dietary n-3/n-6 ratio of 0.432 or higher (17 of 23 cases;70.8%, p < 0.03) compared to that observed for IBD patients who did not comply with the diet. These results emphasize the importance of adjusting dietary PUFA and suggest that the n-3 diet may be effective in maintaining the remission of IBD.

The Relationships between Erythrocyte Membrane n-6 to n-3 Polyunsaturated Fatty Acids Ratio and Blood Lipids and C-reactive Protein in Chinese Adults:An Observational Study

Objective To investigate the relationships between erythrocyte membrane n-6：n-3 PUFAs ratio and blood lipids and high sensitivity C-reactive protein （hs-CRP）. Methods The Chinese and a observational study consisted of a population-based cross-sectiona subsequent 1-year follow-up study of 171 subjects with the fasting cholesterol of 5.13-8.00 mmol/L. study of 456 plasma total Results In the cross-sectional analysis, plasma low-density lipoprotein cholesterol （LDL-c） had a significant and negative association with the erythrocyte membrane n-6：n-3 PUFAs ratio （P for trend=0.019） after adjusting for sex, age and total PUFA percentage. In the follow-up study, 171 subjects were categorized into quartiles by the changes of n-6：n-3 ratio in erythrocyte membrane （△=month 12-month 0）. In the top quartile whose ratios of n-6：n-3 increased by an average of 1.25 during the follow-up, the LDL-c-lowering extent was 3.3 times of that in the lowest quartile whose ratios of n-6：n-3 decreased by an average of 1.13 （-1.07 mmol/L v.s. -0.32 mmol/L）. The hsCRP decreased by 0.11 mg/dL in the lowest quartile while increasing by 0.10 mg/dL in the top quartile （P for difference=0.052）. Conclusion Our results suggested that the balance between n-6 and n-3 fatty acids may optimize the cardiovascular benefits from dietary PUFAs.

Beneficial n-3 polyunsaturated fatty acid levels and n6:n3 ratios after 4-week EPA + DHA supplementation associated with reduced CRP: A pilot study in healthy young adults

Chronic systemic inflammation is associated with many conditions of aging such as atherosclerosis. Lowering high n-6:n-3 polyunsaturated fatty acid (PUFA) ratios are commonly found in Western diets aids in preventing inflammatory-related diseases. However, it is not clear whether dietary interventions designed to alter n-6:n-3 PUFA ratios can reduce systemic inflammation in younger adults. Studies that evaluate PUFA intake often use subjective data from food frequency questionnaires or food records rather than more precise physiological measures of PUFAs (e.g. plasma levels). Therefore, the purpose of this pilot study that analyzed data from the experimental parent study of younger adults (n = 18), was to determine whether plasma PUFA levels were associated with levels of C-reactive protein (CRP), an inflammatory marker, and if supplementation with n-3 PUFAs was correlated with rising n-3 PUFA concentrations in plasma and decreasing n-6:n-3 ratios. In the parent study, participants received daily either placebo or n-3 PUFA softgels (1.6 g eicosapentaenoic acid [EPA] and 1.2 g docosahexaenoic acid [DHA]). EPA and DHA are the biologically active components in fish oil. Measures included blood for PUFA quantification at baseline and four weeks later, when blister wounds were created and wound fluid and saliva were collected. The saliva samples were used to measure CRP in the present study. We report that CRP was significantly and negatively correlated with total n-3 PUFAs (tau-β = ?0.373, p = 0.031) and positively correlated with n-6:n-3 ratios (tau-β = 0.320, p = 0.063). Those consuming EPA + DHA supplements had significantly higher concentrations of total n-3 PUFAs and significantly lower n-6:n-3 ratios (p The present study has shown that beneficial levels of n-3 PUFAs and n-6:n3 ratios were achieved with 4-weeks of EPA + DHA supplementation and were associated with reduced CRP in young adults. EPA + DHA supplementation for some young adults may help prevent inflammatory conditions later in life.

Effects of n-3 Fatty Acids Supplementation on Performance, Relative Organ Weight and Fatty Acid Composition of Thigh Meat in Broiler Chickens

This study was conducted to evaluate the effects of dietary supplementation with marine microbe accumulating n-3 fatty acids on growth performance, relative organ weight and fatty acid composition of thigh meat in broilers. A total of 480 broilers were randomly allotted to three treat-ments with eight replications per treatment and 20 chicks per pen. A corn-soybean meal-based diet was formulated as a control diet and the broilers were then provided with one of the following dietary treatments:(1) CON(basal diet);(2) N0.1(basal diet+0.10% marine microbe accumulating n-3 fatty acids);(3) N0.2(basal diet+0.20% marine microbe accumulating n-3 fatty acids). No significant differences were observed in the growth performance or the relative organ weight among treatments. However, the levels of saturated fatty acids(SFA) and monounsaturated fatty acids(MUFA)were significantly lower(P<0.05) in groups that received the n-3 fatty acids treatments, whereas polyunsaturated fatty acids(PUFA) were increased(P<0.05) significantly in these groups. Overall, these results indicate that dietary supplementation with marine microbe accumulating n-3 fatty acids can increase PUFA and decrease SFA and MUFA in thigh meat.

The scope for manipulating the polyunsaturated fatty acid content of beef:a review

Since 1950, links between intake of saturated fatty acids and heart disease have led to recommendations to limit consumption of saturated fatty acid-rich foods, including beef. Over this time, changes in food consumption patterns in several countries including Canada and the USA have not led to improvements in health. Instead, the incidence of obesity, type II diabetes and associated diseases have reached epidemic proportions owing in part to replacement of dietary fat with refined carbohydrates. Despite the content of saturated fatty acids in beef, it is also rich in heart healthy cis-monounsaturated fatty acids, and can be an important source of long-chain omega-3（n-3） fatty acids in populations where little or no oily fish is consumed. Beef also contains polyunsaturated fatty acid biohydrogenation products,including vaccenic and rumenic acids, which have been shown to have anticarcinogenic and hypolipidemic properties in cell culture and animal models. Beef can be enriched with these beneficial fatty acids through manipulation of beef cattle diets, which is now more important than ever because of increasing public understanding of the relationships between diet and health. The present review examines recommendations for beef in human diets, the need to recognize the complex nature of beef fat, how cattle diets and management can alter the fatty acid composition of beef, and to what extent content claims are currently possible for beef fatty acids.

Influence of Replacement Time and Rate of Soybean Oil by Flax Oil in the Leghorn Hens＇ Diet on Polyunsaturated Fatty Acid Profile in Eggs

The study was aimed to evaluate the effect of replacement time and rate of soybean oil by flax oil （FO） on polyunsaturated fatty acid （PUFA） profile in egg of laying hens. Two hundred White Leghorn hens with 30 weeks of age were divided into five treatments with four replicates of l 0 birds each. Treatments were assigned randomly and consisted of 0.00%, 0.75%, 1.50%, 2.25% and 3.00% FO in commercial corn-soybean meal diets, in which the soybean oil was partially replaced. The experiment was conducted for 90 d. The main research findings were that feed intake, egg production rate, egg weight and feed conversion were not influenced by time and dietary treatment. Fatty acid content was significantly altered （P 〈 0.05） by FO, showing a progressive increase in egg n-3 fatty acid （especially docosahexaenoic acids （DHA） and eicosapentaenoic acids （EPA）） when FO was added. Levels of EPA and DHA were higher （P 〈 0.05） in the egg lipids of FO fed hens than those in the control group. However, no significant differences were observed either in egg weight or egg production among groups. The highest incorporation （P 〈 0.05） of total n-3 fatty acid content in eggs was obtained with 3% FO/kg. This increase was proportional to FO inclusion levels in the diets.

Free fatty acids, glucose, and insulin in type 2 diabetes mellitus

Xu et al used the HOMA2 model to estimate theβ-cell function and insulin resistance levels in an individual from simultaneously measured fasting plasma glucose and fasting plasma insulin levels.This method is based on the assumption that the glucose-insulin axis is central for the metabolic activities,which led to type 2 diabetes.However,significant downregulation of both the NKX2-1 gene and the TPD52L3 gene force an increase in the release of free fatty acids(FFAs)into the blood circulation,which leads to a marked reduction in membrane flexibility.These data favor a FFA-glucose-insulin axis.The authors are invited to extend their study with the introduction of the saturation index(number of carbon-carbon double bonds per 100 fatty-acyl chains),as observed in erythrocytes.

饲料中n-3 HUFA含量对花尾胡椒鲷亲鱼的生殖性能及血浆性类固醇激素水平季节变化的影响

以n 3HUFA含量为 0 16 %、 1 2 7%、 2 36 %和 3 4 7%的 4种人工配合饲料 (D1～D4 )及天然饲料(冰鲜杂鱼 ,D5 )饲养花尾胡椒鲷 (Plectorhynchuscinctus)雌亲鱼一周年 ,通过比较各饲料组亲鱼的产卵量、卵和仔鱼质量以及各月份的血浆性类固醇激素水平 ,研究n 3HUFA对生殖性能及性类固醇激素水平季节性变化的影响。平均每kg雌鱼的产卵量、卵受精率、仔鱼存活率、开口仔鱼体长等 ,D2和D3组与D5组相近 ,但D1和D4组显著低于D5组 ;饲料中n 3HUFA含量对血浆 17β -雌二醇 (E2 )和睾酮 (T)水平的季节性变化规律无明显影响 ,但亲鱼性腺发育与成熟时期的E2 和T水平 ,D1和D4组较D5组显著降低。n 3HUFA含量对亲鱼离体卵泡E2 和T的分泌也有一定影响 :D4组卵泡E2 的基础分泌很少 ;绒毛膜促性腺激素 (HCG ,10 0IU/mL)可刺激D2—D5组卵泡分泌E2 和T ,但D1组卵泡对HCG无反应。结果提示 ,花尾胡椒鲷亲鱼饲料中n 3HUFA的适宜含量为 1 2 7%～ 2 36 % ,不足或过高对亲鱼的生殖性能均有不利影响 ;通过影响性类固醇激素的产生可能是饲料中n

n-3高不饱和脂肪酸对黑鲷幼鱼生长及脂肪代谢的影响

研究了饲料中不同水平n-3 HUFA(0.79%,0.83%,0.85%,0.88%,0.92%,0.94%;DHA/EPA=2.8/1)对黑鲷幼鱼生长及脂肪代谢的影响。结果显示:(1)黑鲷幼鱼肝体指数(HSI)及腹脂率(IPF ratio)随饲料中n-3 HUFA含量的增加而减小,且于0.92%和0.94%组时显著低于其他各组;脂肪细胞直径呈减小趋势,其中0.94%组显著小于0.85%组;肌肉脂肪含量受n-3 HUFA的影响显著,于0.88%组时达到最低。各组全鱼水份和脂肪含量差异不显著(P>0.05)。肝脏、肌肉及腹腔脂肪组织饱和脂肪酸(∑SFA)和C16∶0含量均随饲料n-3HUFA水平增加呈下降趋势,而∑n-3 HUFA呈显著上升趋势。各组织中DHA/EPA不受饲料脂肪酸组成的影响。以增重率为参考指标,二次回归分析结果表明,黑鲷幼鱼[(8.08±0.09)g]获得最佳增重时对饲料中n-3 HUFA的需要量为0.87%DM;(2)黑鲷幼鱼肝脏脂肪酸合成酶(FAS)活性及基因表达水平均在n-3 HUFA>0.92%时有显著下降(P<0.05);腹腔脂肪激素敏感脂肪酶(HSL)活性及基因表达水平均随饲料中n-3 HUFA的添加呈升高趋势(P<0.05),且高含量n-3 HUFA(0.94%)可使HSL活性增加近一倍。结果表明,饲料中n-3HUFA通过同步调控脂肪合成与分解两个过程影响黑鲷幼鱼脂肪代谢。

Effect of dietary incorporation of n-3 polyunsaturated fatty acids rich oil sources on fatty acid profile, keeping quality and sensory attributes of broiler chicken meat

The present study was undertaken to investigate the effect of dietary replacement of commonly used vegetable oil(sunflower oil, SFO) with n-3 polyunsaturated fatty acids(PUFA) rich oil sources on broiler chicken performance, carcass yield, meat fatty acid composition, keeping quality and sensory attributes of meat. In the current experiment, 300 day-old Krishibro broiler chicks were randomly distributed to 5 dietary groups(50 replicates with 6 chicks in each) prepared by replacing SFO(2% and 3% of diet during starter and finisher periods, respectively) with n-3 PUFA rich soybean oil(SO), mustard oil(MO), linseed oil(LO) or fish oil(FO) on weight basis. Variation in oil sources had no influence(P > 0.05) on performance and carcass yield. Supplementation of MO, LO or FO significantly(P < 0.01) increased the n-3 PUFA, lowered the n-6 PUFA deposition and n-6:n-3 ratio in breast and thigh without affecting the organoleptic characters(appearance, flavour, juiciness, tenderness and overall acceptability) of meat.However, thiobarbituric acid reacting substances concentration in meat was increased(P < 0.01) with LO and FO supplementation compared with SFO. It is concluded that, dietary incorporation of MO, LO or FO at 2% and 3% levels during starter and finisher phase can enrich broiler chicken meat with n-3 PUFA without affecting the bird's performance and sensory characters of meat.

饲料中n-3高不饱和脂肪酸含量对三疣梭子蟹幼蟹生长性能及脂肪酸组成的影响

为研究饲料中n-3高不饱和脂肪酸(HUFA)含量对三疣梭子蟹幼蟹生长性能及脂肪酸组成的影响,本试验配制了n-3 HUFA含量分别为0.74%、1.14%、1.55%、1.94%、2.35%、2.76%(干物质基础),且C22∶6n-3(DHA)/C20∶5n-3(EPA)均为1.1的6种等氮等能试验饲料,以初始体重为2.20 g左右的三疣梭子蟹幼蟹为研究对象,在室外水泥池中采用单体筐养方式进行为期8周的生长试验。每种试验饲料投喂60只幼蟹,每20只幼蟹作为1个重复。结果表明:2.35%组的增重率、特定生长率、饲料效率和蜕壳率均为最高,其中增重率和特定生长率显著高于0.74%、1.14%和1.55%组(P<0.05),饲料效率显著高于其他各组(P<0.05),蜕壳率显著高于0.74%、1.14%和1.94%组(P<0.05)。饲料中n-3 HUFA含量对肝胰腺指数没有显著影响(P>0.05)。各组幼蟹的水分、粗蛋白质、粗灰分含量没有显著差异(P>0.05),但0.74%组的粗脂肪含量显著低于其他各组(P<0.05)。幼蟹肌肉及肝胰腺中的脂肪酸组成受到饲料中n-3 HUFA含量的影响,肌肉和肝胰腺中n-3 HUFA含量与饲料中n-3 HUFA含量存在极显著的正相关关系(P<0.01)。以特定生长率为评价指标,通过折线回归分析估测出三疣梭子蟹幼蟹饲料中n-3HUFA的最适含量为2.357%(干物质基础)。

饲料中n-3高度不饱和脂肪酸含量对花尾胡椒鲷亲鱼组织的脂质含量和脂肪酸构成的影响

以n-3高度不饱和脂肪酸(n-3 HUFA)含量(w)为1.12%、2.40%、3.70%、5.85%的4种配合饲料或冰鲜杂鱼喂养花尾胡椒鲷Plectorhynchus cinctus雌亲鱼1周年,研究饲料中n-3 HUFA含量对性腺、肌肉和肝胰脏等组织的脂质含量和脂肪酸构成的影响.结果显示,各组织中的脂质含量在各投喂组之间无显著差异(P>0.05).然而,在1.12%、2.40%和3.70%(w)投喂组,其性腺和肌肉脂质中18∶2n-6、二十碳五烯酸(EPA)、n-3多不饱和脂肪酸(n-3 PUFA)、n-3 HUFA的含量与饲料中相应脂肪酸的含量存在较明显的平行变化趋势;在性腺脂质中,1.12%、2.40%、5.85%(w)投喂组的二十二碳六烯酸(DHA)和1.12%(w)投喂组的n-3 PUFA、n-3 HUFA的含量都显著低于冰鲜杂鱼投喂组(P<0.05);在1.12%、2.40%和3.70%(w)投喂组,上述3种组织中的n-3 PUFA、n-3 HUFA、DHA含量以及DHA/EPA比值都显著高于饲料中相应脂肪酸的含量和比值(P<0.05).结果表明,花尾胡椒鲷组织中的脂肪酸构成受饲料中n-3 HUFA含量影响,受影响的顺序是性腺>肌肉>肝胰脏;组织对n-3 PUFA、特别是DHA具有较强的选择性保留作用,说明这些脂肪酸在性腺发育成熟中具有重要的生理作用.

Azacarbazole n-3 and n-6 polyunsaturated fatty acids ethyl esters nanoemulsion with enhanced efficacy against Plasmodium falciparum

Alternative therapies are necessary for the treatment of malaria due to emerging drug resistance.However,many promising antimalarial compounds have poor water solubility and suffer from the lack of suitable delivery systems,which seriously limits their activity.To address this problem,we synthesized a series of azacarbazoles that were evaluated for antimalarial activity against D10(chloroquine-sensitive)and W2(chloroquine-resistant)strains of P.falciparum.The most active compound,9H-3-azacarbazole(3),was encapsulated in a novel o/w nanoemulsion consisting of ethyl esters of polyunsaturated fatty acids n-3 and n-6 obtained from flax oil as the oil phase,Smix(Tween 80 and Transcutol HP)and water.This formulation was further analyzed using transmission electron microscopy,dynamic light scattering and in vitro and in vivo studies.It was shown that droplets of the 3-loaded nanosystem were spherical,with satisfactory stability,without cytotoxicity towards fibroblasts and intestinal cell lines at concentrations corresponding to twice the IC50 for P.falciparum.Moreover,the nanoemulsion with this type of oil phase was internalized by Caco-2 cells.Additionally,pharmacokinetics demonstrated rapid absorption of compound 3(tmax=5.0 min)after intragastric administration of 3-encapsulated nanoemulsion at a dose of 0.02 mg/kg in mice,with penetration of compound 3 to deep compartments.The 3-encapsulated nanoemulsion was found to be 2.8 and 4.2 times more effective in inhibiting the D10 and W2 strains of the parasite,respectively,compared to non-encapsulated 3.Our findings support a role for novel o/w nanoemulsions as delivery vehicles for antimalarial drugs.

n-3高不饱和脂肪酸对鱼类亲体繁殖性能的影响及其作用机制

n-3高不饱和脂肪酸(HUFA)对鱼类亲体性腺发育、卵子和精子质量、产卵量、受精率、孵化率、仔鱼成活率和质量有重要影响。鱼类体内在一系列去饱和酶和延长酶作用下合成n-3HUFA,淡水鱼类和鲑鳟科鱼类一般从饲料中摄取亚麻酸用于合成n-3 HUFA,而海水鱼类需要从饲料中直接摄取n-3 HUFA。本文综述了鱼体内n-3 HUFA合成路径及其对亲鱼繁殖性能的影响,同时对n-3 HUFA天然来源和替代来源进行了阐述,以期为鱼类亲体的脂肪酸营养和机制方面研究提供一定的参考。