酒精性胃粘膜损伤的研究进展

目的：旨在探讨谷氨酰胺、姜黄素组方对乙醇致大鼠胃粘膜损伤的保护作用及机制。方法：将50只SPF级健康SD雄性大鼠随机分为空白组、模型对照组、西米替丁组、高剂量组、低剂量组5组。连续30 d口服灌胃给药后,除空白组外,其余各组均在无水乙醇造模后处死。通过H&E染色观察胃粘膜组织病理学变化情况,采用试剂盒测定血清丙二醛（malondialdehyde,MDA）、一氧化氮（NO）含量和谷胱甘肽过氧化物酶（Glutathioneperoxidase,GSH-Px）活性,并测定组织中前列腺素E₂（PGE₂）含量水平和血红素加氧酶-1（heme oxygenase-1,HO-1）、NADPH醌氧化还原酶（NADPH Quinone Oxidoreductase 1,NQO1）、抗氧化相关基因核因子-E₂相关因子2（Nuclear factor-E₂ related factor₂,Nrf2）、丝氨酸蛋白激酶-3β（Glycogen synthase kinase-3β,GSK-3β）的表达情况。结果：西米替丁组、高剂量给药组的胃粘膜出血等损伤情况较模型组（P<0.05）均有所缓解,高剂量给药组的效果更明显。此外,模型组MDA含量和GSH-P_X活性明显增加,NO和PGE₂含量明显下降（P<0.05）,抗氧化相关基因HO-1、NQO1和Nrf2表达受到明显抑制,GSK-3β表达明显增加。与模型组相比,西咪替丁组和高剂量给药组MDA含量和GSH-Px活性显著下降,NO、PGE₂含量显著上升（P<0.05）,抗氧化相关基因HO-1、NQO1、Nrf2得到显著恢复（P<0.05）,GSK-3β被抑制（P<0.05）。结论：组方对乙醇引起的急性胃黏膜损伤有抑制作用,其作用机制推测与Keap1-Nrf2-ARE氧化应激通路有关。

     

抗消化淀粉对盐酸/乙醇诱导大鼠胃损伤的影响

以3种抗消化淀粉(RS2、RS3、RS4)为研究对象,采用动物试验法,研究其对盐酸/乙醇诱导大鼠胃损伤的影响。结果表明,3种RS组大鼠的血清IL-6和TNF-α水平、胃损伤程度均低于胃损伤对照组大鼠,而抑制率显著高于胃损伤对照组大鼠,均能减少胃液分泌量、增加胃液pH值,表现出一定的降低胃损伤程度的效果,并且RS3的效果最优。     

Protective effect of polyamine extract of salt stressed and sprouted soybean seeds against ethanol-induced gastric ulcer in rats

The anti-ulcer activity of polyamine extract (PAE) of salt stressed and sprouted soybean seeds against ethanol-induced gastric damage was investigated in a rat model. The contents of the polyamines putrescine (20.11%), spermidine (9.46%), and spermine (2.79%) in PAE were determined using HPLC. The anti-ulcer activity of the extract was compared with the effects of the reference drug omeprazole. Pre- and post-administration of PAE at doses of 10+10, 20, and 20+20mg/kg of body weight in conjunction with ethanol administration significantly protected ethanolinduced gastric damage. The levels of superoxide dismutase and glutathione in stomach tissues were significantly changed, when compared with an ethanol control group. Polyamine extract exhibited high protective effect against ulcer lesions and could be used to develop new anti-ulcer drugs.     

江苏地产浒苔多糖对大鼠急性酒精性胃黏膜损伤的保护作用

为研究江苏地产浒苔多糖对酒精性大鼠胃黏膜损伤的保护作用和机制,将Wistar大鼠随机分成生理盐水组、模型组、浒苔多糖各剂量组（100,200,400 mg/kg）以及阳性对照组（奥美拉唑,300 mg/kg）,每组各10只。采用酒精灌胃致胃黏膜损伤模型。给予浒苔多糖7 d后,观察胃黏膜组织的大体和病理组织改变,测定胃液分泌量、胃酸浓度,胃组织中黏液蛋白、丙二醛（MDA）、氧化物歧化酶（SOD）、谷胱甘肽还原酶（GSH-Px）、大鼠白细胞介素1β（IL-1β）、肿瘤坏死因子（TNF-α）、以及环氧酶（COX-2）等生化指标的活力或含量。结果表明:浒苔多糖能明显改善胃黏膜组织损伤情况,降低损伤积分（p<0.01）,提高酒精性损伤抑制率;在高剂量组能显著降低胃液量的分泌（p<0.05）,提高胃组织GSH-Px,降低炎性因子IL-1β和TNF-α的释放（p<0.01）;各剂量组均能降低胃组织中MDA的含量和COX-2的活力（p<0.05或p<0.01）,显著提高SOD的活力以及胃黏液蛋白的浓度（p<0.05或p<0.01）。江苏地产浒苔多糖对大鼠急性酒精性胃黏膜损伤具有一定保护作用,其机制可能与增强胃黏膜保护因子,提高抗氧化、降低脂质过氧化、抑制炎症因子释放的能力有关。      

Edible oils for liver protection: hepatoprotective potentiality of Moringa oleifera seed oil against chemical-induced hepatitis in rats

In the present study, in vitro antioxidant, antioxidative stress and hepatoprotective activity of Moringa oleifera Lam. seed oil (Ben oil; BO) was evaluated against carbon tetrachloride (CCl(4) ) induced lipid peroxidation and hepatic damage in rats. The oil at 0.2 and 0.4 mL/rat was administered orally for 21 consecutive days. The substantially elevated serum enzymatic (GOT, GPT, ALP, GGT) and bilirubin levels were significantly restored towards normalization by the oil. There was a significant elevation in the level of malondialdehyde (MDA), non-protein sulfhydryl (NP-SH), and total protein (TP) contents in the liver tissue. The results obtained indicated that BO possesses potent hepatoprotective action against CCl(4) -induced hepatic damage by lowering liver marker enzymes, MDA concentration, and elevating NP-SH and TP levels in liver tissue. The biochemical observations were supplemented with histopathological examination of rat liver. The results of this study showed that treatment with Ben oil or silymarin (as a reference) appears to enhance the recovery from hepatic damage induced by CCl(4) . The pentobarbital induced narcolepsy prolongation in mice was retarded by the Ben oil. Acute toxicity test in mice showed no morbidity or mortality. In vitro DPPH radical scavenging and β-carotene-linolic acid assay tests of the BO exhibited a moderate antioxidant activity in both tests used. The possible mechanism(s) of the liver protective activity of Ben oil activity may be due to free radical scavenging potential caused by the presence of antioxidant component(s) in the oil. Consequently, BO can be used as a therapeutic regime in treatment of some hepatic disorders.     

Repeated use of oil for frying fish. Effects of feeding the fried fish to rats

Four groups of weanling male albino rats (Wistar strain) were fed isonitrogenous diet (10% protein) identical in all respects except in the nature of the protein source, for 4 weeks. Control group (group 1) had steamed mackerel meat as the protein source, whereas groups 2, 3 and 4 had mackerel fried on the 1st, 3rd and 4th days in the same coconut oil repeatedly used for frying each day. Four groups of adult male rats weighing around 130 g were fed on the same diet for 12 weeks. Weanlings fed on fish fried on the 4th day showed significantly lower feed consumption and weight gain compared to the other three groups. All the three groups of adult rats fed on fried fish compared well with control rats in weight gain and hepatosomatic index. There was a decrease in the total lipid and cholesterol content of the liver of rats fed with fried fish in comparison with the control rats. The total lipid and cholesterol in heart and serum cholesterol levels increased significantly from control rats through group 4. The C22:6/C20:5 ratio in the heart lipid showed a very high value compared to the dietary lipids. Histopathological examination showed initial stages of cell damage in the liver and kidney of rats fed with fish fried on the 4th day. In-vitro digestibility of proteins of fried fish were lower than that of steamed fish, but the difference in this respect between proteins of fish fried on different days was not significant.     

Intestinal passage of microencapsulated fish oil in rats following oral administration

Fish oil labelled with [(14)C-linolenin] tracer was orally administered by gavage as an oil-water mixture (free oil) or as an oil-in-water emulsion formulation (microencapsulated oil) to fasted rats. Groups of rats were then given food after gavage or alternatively not fed to examine the effect of food on intestinal passage. Feeding after gavage drives lumenal free oil faster through the gastrointestinal (GI) tract. Microencapsulation slows down the lumenal progression in the GI tract with feeding. Non-feeding also slows down the lumenal progress of free oil in the GI tract but this is not influenced by microencapsulation. Analysis of the relative distribution of the label along the GI tract tissue wall showed that the upper small intestine was the main site of label accumulation in the GI tract. Of the oil that remained in the lumen, there was slight protection against early uptake and metabolism in the stomach and upper GI tract in rats that were either fed or not fed after dosing when microencapsulated oil was administered. Microencapsulation increased the levels of radiolabel in the liver and blood. The primary organ for accumulation of radiolabel for both free and microencapsulated oils in rats that were fed or fasted after dosing was the liver.     

Protective effect of sea cucumber (Acaudina molpadioides) fucoidan against ethanol-induced gastric damage

Sea cucumber is a nutritional aquatic food that is widely consumed in East Asian countries. Employing a rat model of ethanol-induced gastric ulcer, we examined the protective effect of sea cucumber fucoidan (SC-FUC) extracted from Acaudina molpadioides and explored the related mechanisms. Oral administration with 100 mg/kg body weight SC-FUC for 5 days can significantly prevent the formation of gastric ulcer. Moreover, SC-FUC pretreatment could alleviate ethanol-induced histological damage, reverse changes in tissue oxidation and antioxidase activities, and regulate the signalling pathways of mitogen-activated protein kinases and matrix metalloproteinases. This study investigated the ethanol-induced gastric ulcer protective effect of SC-FUC for the first time, and elucidated that the protective mechanisms included anti-oxidation, gastric matrix hydrolysis suppression, and anti-inflammation.     

Postprandial lipid responses of butter blend containing fish oil in a single-meal study in humans

The postprandial effects of a butter product containing fish oil were investigated in a single-meal, randomized crossover study with a commercial butter product as the control. Twelve healthy males consumed two test meals with (13)C-labelled cholesterol (45 mg) and either an interesterified butter blend with fish oil (352 mg n-3 long-chain PUFA (LCPUFA)) or the commercial butter blend. Blood samples were collected after the meals and in the fasting condition on the test day and the following morning, and were analysed for cholesterol absorption, plasma lipid profile and fatty acid composition. No significant difference in the postprandial plasma fatty acid composition was observed between the groups, neither difference in cholesterol absorption, plasma cholesterol or the cholesterol contents of plasma lipoproteins. The incorporation of fish oil in the butter resulted in a significant lower concentration of triacylglycerols in the plasma 2 h after the meal in comparison with the commercial butter blend (p = 0.02); there was, however, no significant difference 24 h after the meal. In conclusion, fish oil-enriched butter blend provides a source to increase the intake of n-3 LCPUFA in the population, but has no acute effect on cholesterol absorption and plasma cholesterol concentration in human.     

Diet supplementation with fish oil and sunflower oil to increase conjugated linoleic acid levels in milk fat of partially grazing dairy cows

The objective of this study was to determine the long-term effect on milk conjugated linoleic acid (cis-9, trans-11 CLA) of adding fish oil (FO) and sunflower oil (SFO) to the diets of partially grazing dairy cows. Fourteen Holstein cows were divided into 2 groups (7 cows/treatment) and fed either a control or oil-supplemented diet for 8 wk while partially grazing pasture. Cows in group 1 were fed a grain mix diet (8.0 kg/d, DM basis) containing 400 g of saturated animal fat (control). Cows in the second group were fed the same grain mix diet except the saturated animal fat was replaced with 100 g of FO and 300 g of SFO. Cows were milked twice a day and milk samples were collected weekly throughout the trial. Both groups grazed together on alfalfa-based pasture ad libitum and were fed their treatment diets after the morning and afternoon milking. Milk production (30.0 and 31.2 kg/d), milk fat percentages (3.64 and 3.50), milk fat yield (1.08 and 1.09 kg/d), milk protein percentages (2.97 and 2.88), and milk protein yield (0.99 and 0.91 kg/d) for diets 1 and 2, respectively, were not affected by the treatment diets. The concentrations of cis-9, trans-11 CLA (1.64 vs. 0.84 g/100 g of fatty acids) and vaccenic acid (5.11 vs. 2.20 g/100 g of fatty acids) in milk fat were higher for cows fed the oil-supplemented diet over the 8 wk of oil supplementation. The concentration of cis-9, trans-11 CLA in milk fat reached a maximum (1.0 and 1.64 g/100 g of fatty acids for diets 1 and 2, respectively) in wk 1 for both diets and remained relatively constant thereafter. The concentration of vaccenic acid in milk fat followed the same temporal pattern as cis-9, trans-11 CLA. In conclusion, supplementing the diet of partially grazing cows with FO and SFO increased the milk cis-9, trans-11 CLA content, and that increase remained relatively constant after 1 wk of oil supplementation.     

Physicochemical characterization and oxidative stability of fish oil encapsulated in an amorphous matrix containing trehalose

Fish oil with 33% omega-3 fatty acids was microencapsulated by spray-drying in a matrix of n-octenylsuccinate-derivatized starch and either glucose syrup or trehalose. Samples showed no difference in physicochemical properties as determined by measurement of particle size, oil droplet size, true density and BET surface. Upon storage at low relative humidity, lipid oxidation was decreased in trehalose containing samples indicating that in the amorphous state trehalose is a more suitable wall material for microencapsulation than glucose syrup. The retarded oxidation of trehalose containing samples may be attributed to the unique binding properties of trehalose to dienes. At 54% relative humidity, a rapid oxidation of the microencapsulated oil was observed upon crystallization of trehalose, which limits the range of applications to products to be stored at low humidity.     

小麦低聚肽和谷氨酰胺对大鼠胃肠黏膜损伤的保护作用

观察灌胃小麦低聚肽和谷氨酰胺对非甾体类药物(NSAIDs)致大鼠胃肠黏膜损伤的保护作用。挑选70只SD大鼠随机分为空白对照组、损伤组及低、中、高剂量小麦低聚肽组[灌胃剂量分别为20、100、500 mg/(kg·d)]和小麦蛋白组、谷氨酰胺组[灌胃剂量均为20 mg/(kg·d)]。每天灌胃1次,连续灌胃30 d。大鼠处死前,用非甾体类药物灌胃损伤大鼠胃肠2次。取大鼠血清、胃和小肠黏膜组织,观察血清细胞因子、胃肠病理切片、小肠黏膜抗氧化酶和阿片受体mRNA表达的变化。结果显示非甾体类药物可以显著增加小肠黏膜的氧化应激水平,小麦低聚肽能上调小肠黏膜中GSH-Px的活力,具有一定的抗氧化功能,能够减轻胃肠黏膜损伤。小麦低聚肽还可以显著降低了血清中TNF-α含量,下调mu-阿片受体mRNA的表达。说明非甾体类药物可以诱导大鼠胃肠黏膜损伤的模型,小麦低聚肽可以有效减少大鼠胃肠黏膜损伤。低剂量小麦低聚肽组作用最强,效果优于谷氨酰胺组。     

鹿茸对盐酸-乙醇诱导胃黏膜损伤保护作用的初探

目的:探讨鹿茸对盐酸-乙醇诱导的小鼠胃黏膜损伤的保护作用。方法:将小鼠随机分成对照组、雷尼替丁组、鹿茸糖胺聚糖组、鹿茸水提取物组(低、中、高剂量)和鹿茸粉组(低、中、高剂量)。采用盐酸-乙醇诱导小鼠胃黏膜损伤,检测各组胃黏膜出血情况和损伤指数。结果:对照组小鼠胃黏膜损伤严重。与对照组相比,鹿茸糖胺聚糖组和鹿茸水提取物高剂量组对盐酸-乙醇诱导的胃黏膜损伤具有不同程度的保护作用。结论:鹿茸中糖胺聚糖和蛋白质类成分可以保护胃黏膜免受胃液中H+以及乙醇损伤,对胃黏膜起到保护作用,提示其可用作功能性食品添加物用于胃酸过多及饮酒过度人群。     

Evaluation of microbial transglutaminase and ribose cross-linked soy protein isolate-based microcapsules containing fish oil

Soy protein isolate (SPI)-based microcapsules containing fish oil were prepared using a modified coacervation method followed by cross-linking treatments. The procedure yielded 95–98% microcapsules containing 0.5–0.6 g fish oil/g capsule with a volume mean diameter ranged from ~ 260 to ~ 280 μm. Four types of microcapsules produced were SPI with sucrose (MC-C/S), SPI with ribose (MC-C/R), SPI with sucrose and microbial transglutaminase (MC-MTG/S) and SPI with ribose and MTGase (MC-MTG/R). Protein cross-linking due to ε-(γ-glutamyl)lysine bonds and “Maillard cross-linking” were evidenced in the SDS-PAGE profiles of MC-C/R, MC-MTG/S and MC-MTG/R. Even though the microcapsules prepared with cross-linking treatments had significantly (P < 0.05) lower protein solubility as compared to that of the control, the results of fish oil release in pepsin solution at 37 °C indicated that the core release of all microcapsules prepared with ribose (MC-C/R and MC-MTG/R) was significantly (P < 0.05) lower than other microcapsules. During storage, microcapsules prepared with ribose had longer shelf life as compared to other microcapsules. This may be due to the release of antioxidative Maillard reaction products during heating and storage and a slower rate of gas permeability through the capsules.

Industrial relevance

The use of protein-based wall materials in the food industry for sensitive ingredients is limited because proteins are generally unstable with heating and damaged by organic solvents and the cross-linking agent is usually harmful. Therefore a novel method of combining two familiar cross-linking agents such as the microbial transglutaminase and ribose can convert SPI microcapsules into a stable form. The application of SPI in industry would be increased.     

In vitro lipolysis of fish oil microcapsules containing protein and resistant starch

Microencapsulated fish oil powders (50% oil:25% protein:25% starch) were prepared using a physical blend or a heated mixture of sodium caseinate and pre-processed resistant starch as encapsulants. The in vitro digestibility of microcapsules by lipase, amylase and proteases were examined. Heat treatment of the encapsulants and exposure of microcapsules to simulated gastric fluid (SGF) prior to addition of lipase, trypsin and amylase altered the susceptibility of the microcapsules to digestion. Lipolysis of microcapsules occurred in the presence of lipase alone and was increased in the presence of amylase and/or trypsin. Pre-exposure of microcapsules to SGF had different effects on lipolysis, which depended on the nature of the encapsulant material. Lipolysis in the presence of lipase alone was due to the displacement of the interfacial layer. Increased lipolysis in the presence of amylase and/or trypsin was attributed to the digestion of the encapsulant, which facilitated displacement of the interface of oil droplets by bile salts.     

Microencapsulation of menhaden fish oil containing soluble rice bran fiber using spray drying technology

Emulsion (EFMO) containing purified menhaden oil (PMO) and soluble rice bran fiber (SRBF) was dried in a pilot scale spray dryer and produced microencapsulated PMO with SRBF (MFMO). EFMO had well isolated spherical droplets with the size of 1 to 10 μm and showed pseudoplastic fluid and viscoelastic characteristics. EFMO had lower lipid oxidation than the emulsion containing PMO without SRBF when both emulsions were stored at 20 and 40 °C for 88 h, which indicated that the SRBF reduced the lipid oxidation in the EFMO. The estimated MFMO production rate (3.45 × 10(-5) kg dry solids/s) was higher than the actual production rate (2.31 × 10(-5) kg dry solids/s). The energy required to spray dry the EFMO was 12232 kJ/kg of emulsion. EPA and DHA contents of MFMO were 11.52% and 4.51%, respectively. The particle size of 90% MFMO ranged from 8 to 62 μm, and the volume-length diameter of MFMO was 28.5 μm.