Distinctive roles of unsaturated and saturated fatty acids in hyperlipidemic pancreatitis

AIM: To investigate how the saturated and unsaturated fatty acid composition influences the susceptibility of developing acute pancreatitis. METHODS: Primary pancreatic acinar cells were treated with low and high concentrations of different saturated and unsaturated fatty acids, and changes in the cytosolic Ca2+ signal and the expression of protein kinase C(PKC) were measured after treatment. RESULTS: Unsaturated fatty acids at high concentrations, including oleic acid, linoleic acid, palmitoleic acid, docosahexaenoic acid, and arachidonic acid, induced a persistent rise in cytosolic Ca2+ concentrations in acinar cells. Unsaturated fatty acids at low concentrations and saturated fatty acids, including palmitic acid, stearic acid, and triglycerides, at low and high concentrations were unable to induce a rise in Ca2+ concentrations in acinar cells. Unsaturated fatty acids at high concentrations but not saturated fatty acids induced intra-acinar cell trypsin activation and cell damage and increased PKC expression.CONCLUSION: At sufficiently high concentrations, unsaturated fatty acids were able to induce acinar cells injury and promote the development of pancreatitis. Unsaturated fatty acids may play a distinctive role in the pathogenesis of pancreatitis through the activation of PKC family members.

Dietary saturated fatty acid and polyunsaturated fatty acid oppositely affect hepatic NOD-like receptor protein 3 inflammasome through regulating nuclear factor-kappa B activation

AIM: To investigate the effect of different dietary fatty acids on hepatic inflammasome activation.METHODS: Wild-type C57BL/6 mice were fed either a high-fat diet or polyunsaturated fatty acid (PUFA)-enriched diet. Primary hepatocytes were treated with either saturated fatty acids (SFAs) or PUFAs as well as combined with lipopolysaccharide (LPS). The expression of NOD-like receptor protein 3 (NLRP3) inflammasome, peroxisome proliferator-activated receptor-γ and nuclear factor-kappa B (NF-κB) was determined by real-time PCR and Western blot. The activity of Caspase-1 and interleukine-1β production were measured.RESULTS: High-fat diet-induced hepatic steatosis was sufficient to induce and activate hepatic NLRP3 inflammasome. SFA palmitic acid (PA) directly activated NLRP3 inflammasome and increased sensitization to LPS-induced inflammasome activation in hepatocytes. In contrast, PUFA docosahexaenoic acid (DHA) had the potential to inhibit NLRP3 inflammasome expression in hepatocytes and partly abolished LPS-induced NLRP3 inflammasome activation. Furthermore, a high-fat diet increased but PUFA-enriched diet decreased sensitization to LPS-induced hepatic NLRP3 inflammasome activation in vivo. Moreover, PA increased but DHA decreased phosphorylated NF-κB p65 protein expression in hepatocytes.CONCLUSION: Hepatic NLRP3 inflammasome activation played an important role in the development of non-alcoholic fatty liver disease. Dietary SFAs and PUFAs oppositely regulated the activity of NLRP3 inflammasome through direct activation or inhibition of NF-κB.

Effects of microalgal polyunsaturated fatty acid oil on body weight and lipid accumulation in the liver of C57BL/6 mice fed a high fat diet

Dietary polyunsaturated fatty acids （PUFAs）, which are abundant in marine fish oils, have recently received global attention for their prominent anti-obesogenic effects. Among PUFAs, eicosapentaenoic acid （EPA; 20：5n-3） and docosahexaenoic acid （DHA; 22：6n-3）, which are n-3 long-chain PUFAs widely referred to as omega-3 oils, were reported to prevent the development of obesity in rodents and humans. In the present study, we evaluated the anti-obesity effects of microalgal oil on high-fat induced obese C57BL/6 mice, compared with commercial omega-3 fish oil and vegetable corn oil. Microalgal oil is an inherent mixture of several PUFAs, including EPA, DHA and other fatty acids produced from a marine microalgal strain of Thraustochytriidae sp. derived mutant. It was found to contain more PUFAs （〉80%） and more omega-3 oils than commercial omega-3 fish oil （PUFAs 〉31%） and corn oil （PUFAs 59%）. All three types of oils induced weight loss in high-fat-induced obese mice, with the loss induced by microalgal oil being most significant at 9 weeks （10% reduction）. However, the oils tested did not improve blood lipid levels, although microalgal oil showed an apparent inhibitory effect on lipid accumulation in the liver. These findings may be attributed to the higher PUFA content, including omega-3 oils of microalgal oil than other oils. Collectively, these findings suggest that microalgal oil, derived from Thraustochytriidae sp. derived mutant, is a prominent candidate for replacement of omega-3 fish oils based on its apparent anti-obesity effect in vivo.

Saturated Fatty Acid Induces Insulin Resistance Partially Through Nucleotide-binding Oligomerization Domain 1 Signaling Pathway in Adipocytes

Objective To investigate the potential role of nucleotide-binding oligomerization domain 1 （NOD1）, a component of the innate immune system, in mediating lipid-induced insulin resistance in adipocytes. Methods Adipocytes from Toll-like receptor 4 deficiency mice were used for stimulation experiments. The effect of oleate/palmitate mixture on nuclear factor-κB （NF-κB） activation was analyzed by reporter plasmid assay. The release of proinflammatory chemokine/cytokines production was determined by using real-time PCR. Insulin-stimulated glucose uptake was measured by 2-deoxy-D-[SH] glucose uptake assay. Chemokine/cytokine expression and glucose uptake in adipocytes transfected with small interfering RNA （siRNA） targeting NOD 1 upon fatty acids treatment were analyzed. Results Oleate/palmitate mixture activated the NF-κB pathway and induced interleukin-6, tumor necrosis factor-R, and monocyte chemoattractant protein-1 mRNA expressions in adipocytes from mice deficient in Toll-like receptor 4, and these effects were blocked by siRNA targeting NOD1. Furthermore, saturated fatty acids decreased the ability of insulin-stimulated glucose uptake. Importantly, siRNA targeting NOD 1 partially reversed saturated fatty acid-induced suppression of insulin-induced glucose uptake. Conclusion NOD1 might play an important role in saturated fatty acid-induced insulin resistance in adipocytes, suggesting a mechanism by which reduced NOD1 activity confers beneficial effects on insulin action.

Natural long-chain saturated fatty acids doped LNPs enabling spleen selective mRNA translation and potent cancer immunotherapy

Rationally tailored lipid nanoparticles(LNPs)with efficient and tunable delivery of mRNA in vivo are crucial for mRNA vaccines.Selective expression of antigenic protein in lymphoid tissues/organs could improve the immunostimulatory efficacy and safety of LNPs-based mRNA vaccines.Inspired by the metabolic behavior that long-chain saturated fatty acids tending to enter lymphoid tissue rather than the liver,we developed fatty acid-doped LNPs capable of mediating differential protein expressions in the liver and spleen when administered intravenously.When the molar ratio of saturated fatty acid located 60%–70%,the doped LNPs achieved the spleen selective mRNA translation.The mechanism could be attributed to the different cellular uptake behaviors of saturated fatty acids in hepatocytes.Immunization with a model antigen(ovalbumin)mRNA-loaded spleen selective LNPs,we observed enhanced antigen-specific T cell immune responses,and potent immunotherapeutic and immunoprophylactic efficacy in the mouse lymphoma model.Our natural long-chain saturated fatty acids metabolic characteristics-inspired design of LNPs for spleen-selective mRNA vaccines delivery will provide references for designing mRNA vaccines with high efficacy and safety for tumor immunotherapy.

Reproductive performance and gestational effort in relation to dietary fatty acids in guinea pigs

Background： Dietary saturated（SFAs） and polyunsaturated（PUFAs） fatty acids can highly affect reproductive functions by providing additional energy, modulating the biochemical properties of tissues, and hormone secretions. In precocial mammals such as domestic guinea pigs the offspring is born highly developed. Gestation might be the most critical reproductive period in this species and dietary fatty acids may profoundly influence the gestational effort. We therefore determined the hormonal status at conception, the reproductive success, and body mass changes during gestation in guinea pigs maintained on diets high in PUFAs or SFAs, or a control diet.Results： The diets significantly affected the females＇ plasma fatty acid status at conception, while cortisol and estrogen levels did not differ among groups. SFA females exhibited a significantly lower body mass and litter size, while the individual birth mass of pups did not differ among groups and a general higher pup mortality rate in larger litters was diminished by PUFAs and SFAs. The gestational effort, determined by a mother＇s body mass gain during gestation, increased with total litter mass, whereas this increase was lowest in SFA and highest in PUFA individuals. The mother＇s body mass after parturition did not differ among groups and was positively affected by the total litter mass in PUFA females.Conclusions： While SFAs reduce the litter size, but also the gestational effort as a consequence, PUFA supplementation may contribute to an adjustment of energy accumulations to the total litter mass, which may both favor a mother＇s body condition at parturition and perhaps increase the offspring survival at birth.

Oils with different degree of saturation:effects on ileal digestibility of fat and corresponding additivity and bacterial community in growing pigs

Background Oils are important sources of energy in pig diets.The combination of oils with different degree of saturation contributes to improve the utilization efficiency of the mixed oils and may reduce the cost of oil supplemented.An experiment was conducted to evaluate the effects of oils with different degree of saturation on the fat digestibility and corresponding additivity and bacterial community in growing pigs.Methods Eighteen crossbred(Duroc×Landrace×Yorkshire)barrows(initial body weight:29.3±2.8 kg)were surgically fitted with a T-cannula in the distal ileum.The experimental diets included a fat-free basal diet and 5 oil-added diets.The 5 oil-added diets were formulated by adding 6%oil with different ratio of unsaturated to saturated fatty acids(U:S)to the basal diet.The 5 oils were palm oil(U:S=1.2),canola oil(U:S=12.0),and palm oil and canola oil were mixed in different proportions to prepare a combination of U:S of 2.5,3.5 and 4.5,respectively.Results The apparent and standardized ileal digestibility(AID and SID)of fat and fatty acids increased linearly(P<0.05)as the U:S of dietary oils increased except for SID of fat and C18:2.The AID and SID of fat and fatty acids differed among the dietary treatments(P<0.05)except for SID of unsaturated fatty acids(UFA)and C18:2.Fitted one-slope broken-line analyses for the SID of fat,saturated fatty acids(SFA)and UFA indicated that the breakpoint for U:S of oil was 4.14(R^(2)=0.89,P<0.01),2.91(R^(2)=0.98,P<0.01)and 3.84(R^(2)=0.85,P<0.01),respectively.The determined SID of fat,C18:1,C18:2 and UFA in the mixtures was not different from the calculated SID of fat,C18:1,C18:2 and UFA.However,the determined SID of C16:0,C18:0 and SFA in the mixtures were greater than the calculated SID values(P<0.05).The abundance of Romboutsia and Turicibacter in pigs fed diet containing palm oil was greater than that in rapeseed oil treatment group,and the two bacteria were negatively correlated with SID of C16:0,C18:0 and SFA(P<0.05).Conclusions The optimal U:S for improving the utilization efficiency of mixed oil was 4.14.The SID of fat and UFA for palm oil and canola oil were additive in growing pigs,whereas the SID of SFA in the mixture of two oils was greater than the sum of the values of pure oils.Differences in fat digestibility caused by oils differing in degree of saturation has a significant impact on bacterial community in the foregut.

Effects of Various Foods Intakes on Plasma Levels of Trans Fatty Acids in Japanese Old Men

Background: Trans fatty acids are said to be formed by the partial hydrogenation of vegetable oils. Some amounts are produced in digestive organs of ruminants and present in dairy products or meat. In Japan, use of trans fatty acids in the foods is prohibited, thus trans fatty acids must come from foods or microbes in the digestive organs. Methods: Plasma levels of fatty acids including trans forms of healthy old men are measured by gas chromatography and correlations between various foods intakes and plasma levels of trans fatty acids such as palmitoelaidic, elaidic and linoelaidic acids are examined. Results: No correlations between various foods intakes and trans fatty acids were found except between intake of preference drinks such as tea or coffee and plasma levels of palmitoelaidic and linoelaidic acids. Conclusion: Since palmitoelaidic acid is cardioprotective, increase in plasma levels of palmitoelaidic acid may indicate that intakes of tea and coffee may be beneficial for heath by increasing palmitoelaidic acids.

Correlation of Various Foods Intakes and Plasma Levels of Omega Fatty Acids in Healthy Japanese Old Men

Background: Trans fatty acids are considered to impair health and some ω fatty acids are protective against atherosclerosis and diabetes mellitus. Trans fatty acids are said to be formed by the partial hydrogenation of vegetable oils. Some amounts are produced in digestive organs of ruminants and present in dairy products or meat. It is important how much these intaken fatty acids influence their plasma levels. Methods: Plasma levels of fatty acids including transforms of healthy old men are measured by gas chromatography and correlations between various foods intakes and plasma levels of trans fatty acids, and ω fatty acids are examined. Results: Intake of fish resulted in increase in plasma levels of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) but intake of meat such as beef, cow and chicken meat did not increase plasma levels of arachidonic acid (AA). Intakes of oils increased plasma levels of dihomo-g-linolenic acid significantly and AA to some extent. Conclusion: Plasma levels of EPA and DHA increased upon intakes of fish in Japanese old men. Oil intake but not meat intake increased DGLA significantly. These results may explain low incidence of cardiovascular diseases in Japanese people compared with American people whose plasma levels of DHA and EPA are lower.

Reducing the Levels of Sodium, Saturated Animal Fat, and Nitrite in Dry-Cured Pork Meat Products: A Major Challenge

The curing of meat is a conservation technique widely used since ancient times to prolong shelf-life. It consists in exposing meat to a mixture of sodium chloride and nitrate/nitrite. Sodium chloride affects the flavor, texture and shelf-life of meat products. Animal fat mainly affects the flavor and texture, and nitrate and nitrite affect the color and flavor, and give cured meat products their typical aroma. Excessive intake of sodium has been linked to arterial hypertension and increased risk of cardiovascular diseases. Excessive intakes of saturated fatty acids in pork fat, and also of nitrite, have been identified as factors promoting some cancers. There is consequently an increasing consumer demand to reduce these ingredients in processed meat and so develop healthier cured meat products. This paper reviews how and to what extent sodium, animal fat rich in saturated fatty acids, and nitrite contents can be reduced in the production of dry-cured hams and dry-fermented sausages.

Diet Rich in Saturated Fat Decreases the Ratio of Thromboxane/prostacyclin in Healthy Men

Objective To investigate the effect of dietary saturated fat (SFA) from animal sources on the urine excretion 11-dehydro thromboxane 62 (TXB2) and 6-keto prostaglandin F la (PGF la) in 27 healthy free-living male subjects aged 30 to 55 years. Methods It was a randomized crossover design. Each volunteer was randomly assigned to one of the two diets (high fat and low fat) for a period of 4 weeks, after which each subject resumed his usual diet for 2 weeks as a 'wash-out period', before being assigned to the other diet for an additional 4 weeks. Results Serum proportion of 20:4n-6 was 5% lower in the high fat (6.2% of total fatty acid) than in the low fat diet (6.5% of total fatty acid), which was associated with a significantly decreased ratio of the urinary excretion 11-dehydro TXB2 to 6-keto PGF lα (P<0.05). However, there was no significant fall in the absolute urinary excretion of 11-dehydro TXB2. Conclusions Diet rich in SFA from animal sources may influence TXA2 formation via effect on tissue proportion of 20:4n-6.

液态乳制品中脂肪酸的含量分析

随着居民生活水平的提高,消费者对乳制品的品质提出了更高的要求。为分析液态乳制品中脂肪酸的组成和含量,该文采集13种风味发酵乳和风味酸乳,15种其他液态乳制品,共计28个样品,液态乳制品经过甲酯化处理后,利用气相色谱法进行脂肪酸组成成分和含量的测定。不同来源、不同加工方式液态乳制品中脂肪酸的组成和含量存在一定差异,鲜牛奶和纯牛奶中饱和脂肪酸、单不饱和脂肪酸、多不饱和脂肪酸、ω-3脂肪酸、ω-6脂肪酸、反式脂肪酸和总脂肪酸的含量普遍高于风味发酵乳和风味酸乳,脱脂乳和复原乳发酵乳中脂肪酸含量较低,液态羊乳中脂肪酸的组成和含量与液态牛乳相近。该文评价了28种液态乳制品中脂肪酸的组成和含量的差异性,分析了不同液态乳制品中脂肪酸的组成和含量,为消费者购买高品质液态乳制品提供数据依据。

霍山黄芽提取物对棕榈酸诱导下细胞脂质积累和炎症反应的影响

本研究比较分析了4个不同等级(特一级、特二级、一级、二级)霍山黄芽的主要生化成分和抗氧化活性差异,并选取特一级霍山黄芽,基于棕榈酸诱导的小鼠正常肝细胞AML-12(alpha mouse liver 12)、小鼠神经小胶质细胞BV-2、人肾皮质近曲小管上皮细胞HK-2(human kidney-2)、人胃腺癌细胞(human gastric adenocarcinoma,AGS)细胞模型,研究霍山黄芽提取物(Huoshanhuangya tea extract, HTE)对脂质积累和促炎细胞因子的影响。结果表明:特一级霍山黄芽的可溶性糖质量分数最低,咖啡碱质量分数、儿茶素类质量分数与游离氨基酸总量最高,且抗氧化活性最强;一定质量浓度的HTE处理后,棕榈酸诱导的AML-12、BV-2、HK-2、AGS细胞的细胞活力显著增加,棕榈酸诱导的脂质积累得到改善,棕榈酸诱导的AML-12、BV-2、HK-2细胞中肿瘤坏死因子-α(tumor necrosis factor-α, TNF-α)的释放水平明显降低。进一步探究其作用机制发现,HTE使BV-2细胞中炎症信号通路Toll样受体4(Toll-like receptor 4, TLR4)和核因子-κB RelA(nuclear factor-κB RelA, NF-κB p65)基因的表达下调,表明其可能通过抑制TLR4/NF-κB信号通路的活化来缓解棕榈酸诱导的BV-2细胞炎症损伤。

极长链饱和脂肪酸对人神经母细胞瘤细胞Tau蛋白磷酸化及膜流动性的影响

目的观察极长链饱和脂肪酸对人神经母细胞瘤细胞SH-SY5Y Tau蛋白磷酸化和膜流动性的影响,探讨其在阿尔茨海默病(AD)发病中的作用。方法取对数生长期的人神经母细胞瘤细胞SH-SY5Y,随机分为对照组、C220组、C240组,对照组细胞常规培养,C220组、C240组细胞分别加入含10μmol·L^(-1)极长链饱和脂肪酸C220、C240的培养液,培养24 h后收集细胞,采用Western blot法检测各组细胞中总Tau蛋白、丝氨酸396位点磷酸化Tau蛋白(p-Tau-ser396)、糖原合成酶激酶3β(GSK-3β)及GSK-3β丝氨酸9位点磷酸化蛋白(p-GSK-3β-Ser9)的表达水平;采用硫代巴比妥酸法测定各组细胞中丙二醛(MDA)水平;并采用荧光漂白恢复技术测定细胞膜荧光恢复率和扩散系数,评价细胞膜流动性。结果3组SH-SY5Y细胞总Tau蛋白水平比较差异无统计学意义(F=1.807,P>0.05)。3组SH-SY5Y细胞p-Tau-ser396水平比较差异有统计学意义(F=18.397,P<0.05);其中C220组和C240组SH-SY5Y细胞p-Tau-ser396水平显著高于对照组(P<0.05),C240组SH-SY5Y细胞p-Tau-ser396水平显著高于C220组(P<0.05)。3组SH-SY5Y细胞GSK-3β蛋白水平比较差异无统计学意义(F=0.351,P>0.05)。3组SH-SY5Y细胞p-GSK-3β-Ser9水平比较差异有统计学意义(F=13.330,P<0.05);其中C220组、C240组SH-SY5Y细胞p-GSK-3β-ser9水平显著低于对照组(P<0.05),C220组与C240组SH-SY5Y细胞p-GSK-3β-ser9水平比较差异无统计学意义(P>0.05)。C240组SH-SY5Y细胞MDA水平显著高于对照组和C220组(P<0.05);对照组与C220组SH-SY5Y细胞MDA水平比较差异无统计学意义(P>0.05)。对照组、C220组、C240组SH-SY5Y细胞的荧光恢复率和扩散系数有降低趋势,但3组SH-SY5Y细胞的荧光恢复率和扩散系数比较差异无统计学意义(F=3.891、3.649,P>0.05)。结论极长链饱和脂肪酸C220、C240可促进Tau蛋白过度磷酸化,诱导细胞氧化损伤,对细胞膜流动性也有降低趋势,极长链饱和脂肪酸可能是引起AD发病的因素之一。

腹部脂肪组织脂肪酸组分的MRI定量检测及其在直肠癌中的应用价值初探

目的:利用化学位移编码磁共振成像(chemical-shift-encoded magnetic resonance imaging,CSE-MRI)技术定量检测脂肪组织脂肪酸组分,分析直肠癌患者不同部位脂肪酸组分变化情况,探讨该技术应用于评价脂肪酸影响直肠癌发生、发展的价值。方法:对2021年10月—2022年12月于复旦大学附属华东医院经术后病理学检查证实的直肠腺癌患者术前行直肠常规MRI扫描和多回波梯度回波CSE-MRI检查以测定直肠系膜、肠系膜和臀部皮下3个部位的脂肪组织脂肪酸组分[包括饱和脂肪酸分数(fraction of saturated fatty acid,fSFA)、单不饱和脂肪酸分数(fraction of monounsaturated fatty acid,fMUFA)和多不饱和脂肪酸分数(fraction of polyunsaturated fatty acid,fPUFA)]。同期入组与年龄性别相匹配的对照组非直肠癌患者20例。分析直肠癌组与对照组间以及直肠癌患者中各部位脂肪组织脂肪酸组分变化,评价脂肪酸在肿瘤发生发展过程中的作用;分别分析直肠癌淋巴血管侵犯(lymphovascular invasion,LVI)、周围神经侵犯(peripheral nerve invasion,PNI)阳性组和阴性组各部位脂肪组织脂肪酸组分变化,评价脂肪酸对肿瘤侵袭性的影响。脂肪酸分数参数测量的观察者间一致性通过组内相关系数(intraclass correlation coefficient,ICC)评估。两组间差异分析用独立样本t检验或Mann-Whitney U检验;多组间差异分析用单因素方差分析(One-Way ANOVA)或Kruskal-Wallis H(K)检验。结果:共纳入56例直肠腺癌患者,包括男性36例,女性20例,平均(65.1±10.1)岁;LVI阳性11例(19.6%),PNI阳性10例(17.9%)。对照组20例,其中男性12例,女性8例,平均(66.3±8.8)岁。观察者间各部位各脂肪酸分数的测量相关性良好,ICC均>0.60。直肠癌组中直肠系膜脂肪组织fSFA高于对照组(37.2±4.2 vs 35.0±2.7,P=0.035);直肠癌患者中直肠系膜、肠系膜与臀部皮下脂肪组织中的fMUFA(分别为37.5±2.4、37.3±8.1和40.6±8.7,P=0.003)和fPUFA(分别为24.9±4.1、26.3±4.9和21.5±4.7,P<0.001)的差异均有统计学意义;LVI(+)直肠癌直肠系膜脂肪中fMUFA高于LVI(-)组(38.8±1.5 vs 37.1±2.5,P=0.035);PNI(+)/(-)直肠癌组间各部位脂肪组织各脂肪酸分数差异均无统计学意义(P>0.05)。结论:①直肠癌患者直肠系膜脂肪SFA分数与正常对照组存在差异;②直肠癌患者直肠系膜和肠系膜脂肪的fMUFA和fPUFA与皮下脂肪组织之间存在差异;③直肠癌患者直肠系膜脂肪fMUFA与LVI存在关联。

不同饵料对大刺鳅生长和肌肉中氨基酸、脂肪酸的影响

为了了解生物饵料添加对大刺鳅(Mastacembelus armatus)养殖效果的影响,在大刺鳅的饲料中添加了红虫(Chironomidae)、黄粉虫(Tenebrio molitor)和大麦虫(Zophobas atratus),结果发现:30 d时,添加大麦虫组的鱼体质量显著高于其他3组(P<0.05),饲料组最低。60 d时,添加大麦虫组鱼体质量依然显著高于其他3组(P<0.05)。通过氨基酸检测,添加黄粉虫组的鱼总氨基酸显著高于其他3组(P<0.05),而在鲜味氨基酸上,添加大麦虫组鱼体质量显著高于其他3组(P<0.05)。4组二十碳五烯酸(EPA)与二十二碳六烯酸(DHA)均无显著差异,添加大麦虫的饱和脂肪酸、单不饱和脂肪酸、多不饱和脂肪酸均显著高于其他3组。实验结果表明,投喂添加大麦虫的大刺鳅饵料,鱼的增重效果、肥满度和鲜味氨基酸含量等重要指标上均为最佳。

脂肪酸种类及含量与膝骨关节炎的发病风险

背景:近年来,流行病学研究显示肥胖是膝骨关节炎的危险因素,而脂肪酸的摄入、代谢和生物合成与肥胖的发生发展密切相关,但脂肪酸与膝骨关节炎之间是否存在因果关联仍未知。目的:应用孟德尔随机化分析方法探讨5种脂肪酸表型与膝骨关节炎的因果关联。方法:使用来自英国生物银行(met-D)的脂肪酸比例的全基因组关联研究数据和来自EBI-A数据库的膝骨关节炎的全基因组关联研究数据进行汇总,将单核苷酸多态性(single nucleotide polymorphism,SNP)作为工具变量并选择敏感的SNPs进行分析,通过双样本孟德尔随机化分析,以评估脂肪酸与膝骨关节炎结局风险的因果关系。采用逆方差加权法、MR-Egger回归法、加权中位数法、加权模型法和简单模型法来研究脂肪酸与膝骨关节炎之间的因果关系。进一步以同样方法进行反向孟德尔随机化分析,确保结果的有效性。结果与结论:①正向分析逆方差加权法结果表明,共有3种脂肪酸表型与膝骨关节炎有因果关系,其中饱和脂肪酸占总脂肪酸的比例(OR=1.825,95%CI:1.230-2.706,P=0.003)与膝骨关节炎的发病风险呈正相关、Ω3多不饱和脂肪酸占总脂肪酸的比例(OR=0.822,95%CI:0.689-0.981,P=0.03)与膝骨关节炎的发病风险呈负相关以及Ω6多不饱和脂肪酸占总脂肪酸的比例(OR=1.268,95%CI:1.079-1.491,P=0.004)与膝骨关节炎的发病风险呈正相关;有2种脂肪酸表型与膝骨关节炎不具有因果关系,为总脂肪酸(OR=0.925,95%CI:0.804-1.066,P=0.283)、单不饱和脂肪酸占总脂肪酸的比例(OR=0.877,95%CI:0.756-1.018,P=0.084)。②反向分析结果表明,当膝骨关节炎作为暴露数据时,与脂肪酸的表型均不具有显著因果关系。③敏感性分析结果显示:双向孟德尔随机化的Cochran’s Q检验和MR-Egger回归法的结果P值均大于0.05,表明脂肪酸表型与膝骨关节炎之间的因果效应分析不存在显著的异质性和多效性。④上述结果证实,降低饱和脂肪酸、Ω6多不饱和脂肪酸的含量和提升Ω3多不饱和脂肪酸的含量能降低膝骨关节炎发病的风险,这为研究膝骨关节炎的生物学机制以及探索膝骨关节炎的早期防治提供有价值的线索,也为干预性药物的开发提供了新的方向。

饱和脂肪酸积累在非酒精性脂肪性肝炎中的作用机制及相关药物研究进展

非酒精性脂肪性肝炎(NASH)的特点是肝细胞内过多的脂肪积累、肝组织炎症及细胞损伤。在NASH发展过程中,饱和脂肪酸(SFA)的积累被认为是主要病理机制之一,调节SFA的代谢能够缓解NASH的发生发展。该文对SFA的积累在NASH发病过程中的作用机制及相关药物研究进展进行整理与分析,以期为NASH的治疗提供参考依据。

乙烯利喷施对油茶脂肪酸成分和果实生长发育的影响

为促进植物激素乙烯利调控油茶脂肪酸成分含量和果实生长发育,以‘湘林210’为试验材料,采用GC-MS分析技术和田间试验观测等手段,研究在油脂合成初期喷施1.5 g·L^(-1)乙烯利对油茶果实发育过程中种仁含油率、脂肪酸成分含量和果实性状指标的影响。结果表明,喷施乙烯利后虽然对果实成熟期种仁含油率无显著影响,但可显著提高处理后7和30 d的种仁含油率,分别提高了36.53%和3.37%;喷施乙烯利后可以显著提高果实成熟期种仁亚油酸、亚麻酸和棕榈酸含量,分别提高了11.92%、11.54%和3.53%;却显著降低了花生烯酸和硬脂酸含量,分别降低了13.79%和14.51%;喷施乙烯利后显著降低了油茶果实发育过程中的果皮厚度和种仁含水率,分别降低了22.03%和7.36%;但对鲜果质量、鲜籽质量、鲜出籽率、果实的横径和纵径,以及叶片叶绿素和胡萝卜素含量的影响不显著。

Effects of the ratio of unsaturated fatty acid to saturated fatty acid on the growth performance,carcass and meat quality of finishing pigs

The effects on finishing pigs(80-100 kg BW) fed diets supplemented with oil sources containing different ratios of unsaturated to saturated fatty acids(UFA:SFA ratio) were evaluated in 15 barrows and15 gilts(Duroc × Large White × Landrace). Three experimental diets were evaluated using a randomized complete block design, with broken rice, soybean meal and rice bran as the main feedstuffs in the control diet. Diets 2 and 3 consisted of the control diet supplemented with 3% oil, with UFA:SFA ratios of 2.5:1 and 5:1, respectively. Overall, there was no significant difference(P> 0.05) found in the average daily gain(ADG) of the pigs fed the treatment diets; however, the pigs fed the control diet and diet 3 had better(P < 0.05) feed conversion ratios(FCR) than the pigs fed diet 2. The pigs fed diets 2 and 3, which were supplemented with oil at UFA:SFA ratios of 2.5:1 and 5:1, had greater(P < 0.05) average daily feed intakes(ADFI) than the pigs in the control group. Additionally, it was found that the gender of the pigs had an effect(P < 0.05) on the FCR. Interaction effects between the experimental diets and the gender of the pigs(P < 0.05) were found in the ADFI and FCR. There were no significance differences(P > 0.05)among the treatment groups with regard to the carcass quality of the pigs; however, it was found that the gilts had greater(P < 0.01) loin eye areas than the barrows fed diets 2 and 3 and the loin eye area of pig fed diet 2 was the largest(P < 0.05); In the case of the meat quality parameters, it was clearly found that the pigs fed the control diet had a greater(P < 0.05) lightness(L~*) in the meat colour, and the lowest cooking loss was found in the pigs fed the diet supplemented with fat containing the UFA:SFA ratio of 5:1.Overall, the dietary treatment did not significantly affect the drip loss, thawing loss and shear force of the pork. In conclusion, the supplementation of oil with UFA:SFA ratios of 2.5:1 and 5:1 has the potential to improve pork quality.