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(Dh A) had thepotential to inhibit NLRP3 inflammasome expression in hepatocytes and partly abolished LPS-induced NLRP3 inflammasome activation. Furthermore, a highfat diet increased but PUFA-enriched diet decreased sensitization to LPS-induced hepatic NLRP3 inflammasome activation in vivo. Moreover, PA increased but Dh A decreased phosphorylated NF-κB p65 protein expression in hepatocytes.CONCLUSION:Hepatic NLRP 3 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.

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.

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-[3H]glucose uptake assay.Chemokine/cytokine expression and glucose uptake in adipocytes transfected with small interfering RNA(siRNA)targeting NOD1 upon fatty acids treatment were analyzed.Results Oleate/palmitate mixture activated the NF-κB pathway and induced interleukin-6,tumor necrosis factor-α,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 NOD1 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.

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.

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.

Long-term high fructose and saturated fat diet affects plasma fatty acid profile in rats

As the consumption of fructose and saturated fatty acids(FAs) has greatly increased in western diets and is linked with an increased risk of metabolic syndrome,the aim of this study was to investigate the effects of a mod-erate(10 weeks) and a prolonged(30 weeks) high fructose and saturated fatty acid(HFS) diet on plasma FA com-position in rats.The effects of a few weeks of HFS diet had already been described,but in this paper we tried to es-tablish whether these effects persist or if they are modified after 10 or 30 weeks.We hypothesized that the plasma FA profile would be altered between 10 and 30 weeks of the HFS diet.Rats fed with either the HFS or a standard diet were tested after 10 weeks and again after 30 weeks.After 10 weeks of feeding,HFS-fed rats developed the metabolic syndrome,as manifested by an increase in fasting insulinemia,total cholesterol and triglyceride levels,as well as by impaired glucose tolerance.Furthermore,the plasma FA profile of the HFS group showed higher proportions of monounsaturated FAs like palmitoleic acid [16:1(n-7)] and oleic acid [18:1(n-9)],whereas the proportions of some polyunsaturated n-6 FAs,such as linoleic acid [18:2(n-6)] and arachidonic acid [20:4(n-6)],were lower than those in the control group.After 30 weeks of the HFS diet,we observed changes mainly in the levels of 16:1(n-7)(decreased) and 20:4(n-6)(increased).Together,our results suggest that an HFS diet could lead to an adaptive response of the plasma FA profile over time,in association with the development of the metabolic syndrome.

基于泡腾辅助脂肪酸形态转化的悬浮固化-分散液液微萃取测定水样中环境雌激素

本研究建立脂肪酸形态转化液液微萃取技术并结合高效液相色谱对湖水和河水中雌酮、己烯雌酚和己烷雌酚这3种环境雌激素(EEs)进行了测定.利用脂肪酸可在亲水-疏水形态间转换的特点,对5种中链脂肪酸筛选得到辛酸作为萃取剂,同时根据其低温固化的特点,利用漂浮液滴固化微萃取技术进行测定.通过实验设计优化最优萃取条件为:H_(2)SO_(4)(98%)体积238μL、Na_(2)CO_(3)(2 mol·L^(-1))体积413μL、脂肪酸体积144μL和涡旋时间3.3 min.最优萃取条件下检测,定量限范围0.110-0.201μg·L^(-1),回收率范围89.0%—101.5%.本方法具有简便快捷,检测限低,回收率高,绿色环保等优点,适用于多种环境水体中EEs的快速定性及定量分析.

饲粮中添加牛至精油后平凉红牛肌肉品质、脂肪酸及氨基酸的组成和含量

选取健康状况良好、初始体重相近的9头平凉红牛阉牛,分为3组,每组3头。对照组(CON组)饲喂基础饲粮,试验组则在基础饲粮基础上每头每天添加10 g(L组)、20 g(H组)牛至精油,预试期14 d,正试期570 d,取左半胴体半腱肌测定肉品质、脂肪酸和氨基酸含量,研究长期添加牛至精油后平凉红牛肌肉品质、脂肪酸及氨基酸的组成和含量变化。结果表明:1)排酸时间相同牛至精油添加量不同时,排酸0 h,L组失水率显著低于CON组(P <0.05),H组熟肉率显著高于CON组(P <0.05),L组剪切力显著低于CON组(P <0.05)。排酸72 h后,H组肌肉亮度值显著高于CON组(P <0.05),试验组滴水损失显著低于CON组(P <0.05),L组蒸煮损失显著低于CON组(P <0.05)。牛至精油添加量相同排酸时间不同时,CON组中,72 h肌肉亮度、红度值、黄度值、失水率和蒸煮损失显著高于0 h(P <0.05),0 h pH和熟肉率显著高于72 h(P <0.05)。L组中,72 h肌肉亮度值、黄度值和失水率显著高于0 h(P <0.05),0 h pH显著高于72 h(P <0.05)。H组中,72 h肌肉亮度值、红度值、失水率和蒸煮损失显著高于0 h(P <0.05),0 h pH和熟肉率显著高于72 h(P <0.05)。2)试验组硬脂酸(C18:0)、油酸(C18:1n9c)和不饱和脂肪酸(USFA)含量显著高于CON组(P <0.05),L组山嵛酸(C22:0)显著高于CON和H组(P <0.05)。3)试验组苏氨酸、缬氨酸、蛋氨酸、异亮氨酸、亮氨酸、苯基丙氨酸、赖氨酸、丙氨酸、天冬氨酸、丝氨酸、脯氨酸、酪氨酸、精氨酸、必需氨基酸、非必需氨基酸和氨基酸总量显著高于CON组(P <0.05),L组谷氨酸含量显著高于CON组(P <0.05)。综上所述,长期饲喂牛至精油可以改善育肥后期平凉红牛的肌肉品质并提升肌肉中脂肪酸和氨基酸含量。

基于仿生胃肠道消化技术的不饱和脂肪酸体外发酵特性及其对肠道菌群影响研究

脂肪酸是维持人体生存的必需营养物之一。国内外一致认为二十二碳六烯酸(docosahexaenoic acid,DHA)和二十碳四烯酸(arachidonic acid,AA)对大脑的发育具有重要的意义。肠道微生物与人体健康息息相关,然而对于不同浓度、不同饱和度的脂肪酸对肠道菌群的影响尚无相关研究。该研究从omega-3、6族中各挑选出代表性的脂肪酸,以DHA、AA、椰子油作为研究对象,通过油脂的乳化技术和体外动态仿生大肠反应器,对健康成人的肠道菌群进行体外厌氧发酵培养,探究了不同浓度、不同饱和度的脂肪酸对肠道菌群及代谢的影响。结果表明,2 mL/L DHA组中短链脂肪酸乙酸、丙酸、丁酸浓度分别达到了54.79、8.34、1.45 mmol/L,比2 mL/L阳性对照组分别变化了11.48%、-1.41%和66.98%,并且16S rDNA测序显示2 mL/L DHA组还稳定了肠道菌群,上调了不动杆菌属和双歧杆菌属等有益菌属。此外,低不饱和度脂肪酸较高不饱和度脂肪酸表现出更高的益生活性。该研究结果表明2 mL/L低饱和度的脂肪酸DHA对健康成人的肠道菌群具有正向影响。

高脂饮食条件下极长链饱和脂肪酸对大鼠认知功能的影响及相关机制

目的:探讨高脂饮食条件下极长链饱和脂肪酸(VLCSFA)对大鼠认知功能的影响及相关机制。方法:将50只雄性SD大鼠随机分为5组,每组10只,即空白对照组组(饲喂基础饲料)、低含量对照(L-CON)组(饲喂20%对照用油)、低含量VLCSFA(L-VLC)组(饲喂20%实验用油)、高含量对照(H-CON)组(饲喂30%对照用油)和高含量VLCSFA(H-VLC)组(饲喂30%实验用油),饲喂12周。Morris水迷宫测定大鼠学习记忆能力;气相色谱法检测脑皮质脂肪酸组成及含量;生化法检测脑氧化应激水平;ELISA法检测脑促炎因子水平;Western blot法检测脑中β-分泌酶(BACE1)、α-分泌酶(ADAM10)、磷酸化tau蛋白及细胞凋亡相关蛋白的水平。结果:与L-CON组相比,LVLC组大鼠穿越平台次数显著减少(P<0.05),脑皮质C21:0、C22:0、C23:0、C24:0、C26:0和ΣVLCSFA含量显著增加(P<0.05或P<0.01),ADAM10蛋白水平显著下降(P<0.01),BACE1和p-tau396蛋白水平显著升高(P<0.05),谷胱甘肽过氧化物酶(GSH-Px)活性显著降低(P<0.01),丙二醛(MDA)水平显著升高(P<0.05),白细胞介素6(IL-6)和肿瘤坏死因子(TNF-α)水平显著升高(P<0.01);与H-CON组相比,H-VLC组大鼠逃避潜伏期显著延长(P<0.05),脑皮质C20:0、C21:0、C22:0、C23:0、C24:0、C26:0和ΣVLCSFA含量均显著升高(P<0.05或P<0.01),ADAM10蛋白水平显著下降(P<0.01),BACE1、p-tau396和p-tau404蛋白水平显著升高(P<0.01),超氧化物歧化酶(SOD)和GSHPx活性显著降低(P<0.05或P<0.01),MDA水平显著升高(P<0.05),IL-1β、IL-6和TNF-α水平显著升高(P<0.01),B细胞淋巴瘤/白血病蛋白2(Bcl-2)水平显著降低(P<0.05),Bcl-2相关X蛋白(Bax)和cleaved caspase-3蛋白水平显著升高(P<0.05或P<0.01)。结论:通过高脂饮食大量摄入VLCSFA会损害大脑认知功能,其机制可能与脑组织VLCSFA积累增多、淀粉样前体蛋白代谢、tau蛋白过度磷酸化、氧化应激、神经炎症和细胞凋亡有关。

基于脂肪酸差异分析黔北麻羊腿肉品质

通过对贵州黔北麻羊、内蒙古绵羊和宁夏滩羊羊腿肉中脂肪和脂肪酸的组成和含量进行检测,对比分析3个地区羊腿肉的差异及特征。实验收集贵州黔北麻羊27例、内蒙古绵羊12例和宁夏滩羊15例的羊后腿肉,参照食品安全国家标准对3个地区羊肉的脂肪和脂肪酸进行提取并检测其含量。使用ANOVA结合正交偏最小二乘法判别分析(orthogonal partial least squares discriminant analysis,OPLS-DA)法分析3个地区羊腿肉的脂肪酸差异。结果表明,贵州黔北麻羊腿肉脂肪平均含量为3.30%,极显著低于内蒙古绵羊和宁夏滩羊(P<0.01);在3种羊腿肉中共检测出12种脂肪酸,含量为0.53%~42.45%;发现黔北麻羊羊腿肉中的豆蔻酸、十七烷酸、二十一碳酸和反式油酸含量显著低于内蒙古绵羊,而棕榈酸、棕榈一烯酸、油酸和亚油酸则显著高于内蒙古绵羊(P<0.05);贵州黔北麻羊中的豆蔻酸、十五碳酸、十七烷酸、十七烷一烯酸、反式油酸含量显著低于宁夏滩羊(P<0.01),硬脂酸、油酸含量显著高于宁夏滩羊(P<0.05),脂肪和脂肪酸显著的含量差异特征造成了羊肉品质差异。OPLS-DA分析发现黔北麻羊与其他2个地区的差异脂肪酸为油酸、豆蔻酸、十七烷酸和反式油酸等。