小麦肽免疫活性及抗氧化作用的研究

本文旨在研究Alcalase水解小麦蛋白产物中免疫活性组分对小鼠免疫功能和抗氧化功能的调节作用及相互关系.实验结果表明,小麦活性肽可提高小鼠抗体生成细胞含量、血清溶血素水平、脾细胞增殖能力以及腹腔巨噬细胞的吞噬能力;小麦活性肽还可提高小鼠血清清除DPPH和清除羟自由基的能力,增强小鼠肝脏超氧化物歧化酶活性、过氧化氢酶活力和总抗氧化能力,降低丙二醛含量.且该组分调节机体抗氧化的能力与其免疫调节作用具有一定的相关性.     

马鹿茸血酶解肽体内免疫功能及抗氧化功能关系的研究

本文分别选用由木瓜蛋白酶水解天山马鹿茸血获得的肽Ⅰ、肽Ⅱ以及原血为受试样品,研究天山马鹿茸血及其酶解肽对小鼠免疫功能和抗氧化功能的影响,其中肽Ⅰ、肽ⅡDH分别为18．1％、12．2％时,清除OH·能力最强,清除率为50．8％。分别测定了脏器指数,脾细胞增殖实验,血清中溶血素和抗体生成细胞的含量以及小鼠血清总抗氧化能力、SOD活力和MDA含量。结果表明：与对照组相比较,肽Ⅱ组能极显著提高小鼠体液和细胞免疫功能,加强小鼠的抗氧化功能（P〈0．01或P〈0．05）。此外,具有较强抗氧化活性的肽显示出了很强的免疫活性（P〈0．05）。     

黄鳍金枪鱼头蛋白酶解液对小鼠免疫功能的调节作用

以金枪鱼头为原料,经酶解得到蛋白酶解液;以环磷酰胺造小鼠免疫功能低下模型,同时灌胃金枪鱼头蛋白酶解液,观察小鼠免疫脏器指数,巨噬细胞吞噬功能,ConA刺激的淋巴细胞增殖和溶血空斑细胞形成能力。结果显示金枪鱼头蛋白酶解液能显著增强免疫抑制状态下的小鼠腹腔巨噬细胞吞噬能力和胸腺、脾脏指数;明显提高免疫抑制状态小鼠的脾淋巴细胞转化能力及抗体细胞形成能力。说明金枪鱼头蛋白酶解液对环磷酰胺造成的免疫功能低下小鼠的非特异性免疫和特异性免疫功能都有正向调节作用。     

一种双歧杆菌胞外多糖免疫调节功能研究

根据保健食品功能评价规范?功能学评价程序研究一种双歧杆菌胞外多糖(Bifidobacterium spp. exopolysaccharide, EPS)的免疫调节功能。通过脾淋巴细胞增殖反应、绵羊红细胞诱导小鼠迟发型变态反应(DTH)、血清溶血素测定以及巨噬细胞吞噬实验探讨该EPS的免疫调节活性。EPS分别以高、中、低剂量组连续口服给药10天, 结果发现低剂量的EPS[100 mg/(kg·d)]可以促进脾淋巴细胞增殖; 高、中、低剂量对绵羊红细胞诱导的小鼠迟发型变态反应均无促进作用; 但是, EPS 高、中、低剂量组均能明显提高小鼠血清半数溶血值HC50以及增强小鼠腹腔巨噬细胞吞噬鸡红细胞的吞噬能力。根据规范可知, 该双歧杆菌EPS 具有一定的免疫调节活性。     

油橄榄叶提取物体内外抗氧化活性研究北大核心CSCD

为评价油橄榄叶提取物的体内和体外抗氧化能力,体外抗氧化活性评价采用DPPH·和·OH清除能力实验,体内抗氧化活性评价采用D-半乳糖连续背部注射制作亚急性衰老小鼠模型,以VE为阳性对照组,油橄榄叶提取物58、116、232 mg/kg BW灌胃30 d,处死后测定MDA含量、SOD和GSH-Px活性,观察肝脏和大脑组织病理形态学的改变。结果表明,衰老小鼠MDA的含量明显升高,血清、肝组织中的SOD、GSH-Px和脑组织中的SOD活性均明显降低,与正常小鼠比较有差异(P<0.05);各剂量的油橄榄叶提取物均能提高衰老小鼠血清、肝组织中的SOD、GSH-Px和脑组织中的SOD活性,并降低MDA的含量;油橄榄叶提取物可明显改善D-gal致衰老小鼠肝脏、大脑皮质和海马神经元的细胞形态和水肿情况。油橄榄叶提取物清除DPPH·和·OH的IC50分别为0.064 mg/m L和0.066 mg/m L。实验结果表明油橄榄叶提取物具有较好的抗氧化活性。     

油橄榄叶提取物体内外抗氧化活性研究

为评价油橄榄叶提取物的体内和体外抗氧化能力,体外抗氧化活性评价采用DPPH·和·OH清除能力实验,体内抗氧化活性评价采用D-半乳糖连续背部注射制作亚急性衰老小鼠模型,以VE为阳性对照组,油橄榄叶提取物58、116、232 mg/kg BW灌胃30 d,处死后测定MDA含量、SOD和GSH-Px活性,观察肝脏和大脑组织病理形态学的改变。结果表明,衰老小鼠MDA的含量明显升高,血清、肝组织中的SOD、GSH-Px和脑组织中的SOD活性均明显降低,与正常小鼠比较有差异(P0.05);各剂量的油橄榄叶提取物均能提高衰老小鼠血清、肝组织中的SOD、GSH-Px和脑组织中的SOD活性,并降低MDA的含量;油橄榄叶提取物可明显改善D-gal致衰老小鼠肝脏、大脑皮质和海马神经元的细胞形态和水肿情况。油橄榄叶提取物清除DPPH·和·OH的IC50分别为0.064 mg/m L和0.066 mg/m L。实验结果表明油橄榄叶提取物具有较好的抗氧化活性。     

日本虫草子实体多糖抗氧化及免疫调节作用

为明确日本虫草子实体多糖（CJPs）的抗氧化活性及免疫调节作用,本研究以子实体为原料,采用热水浸提法得多糖,通过对ABTS自由基、DPPH自由基、·OH自由基清除能力评价CJPs的体外抗氧化活性;探讨CJPs对氢化可的松诱导的免疫抑制小鼠的免疫调节作用。结果表明,CJPs对ABTS、DPPH、·OH自由基均有明显的清除效果,且存在量效关系,IC₅₀分别为0.165、0.098、0.253mg/mL;灌胃CJPs的小鼠与模型组相比,免疫器官指数、巨噬细胞吞噬指数、血清中细胞因子水平、免疫球蛋白含量均有所提高,脾脏中乳酸脱氢酶（LDH）和酸性磷酸酶（ACP）的活力显著增强（P<0.05或P<0.01）。该研究表明CJPs是一种潜在的抗氧化剂,并能显著提高免疫低下小鼠的免疫功能,为其进一步研究和应用提供了科学依据。     

有用微生物提取物（EM—X）对果蝇和小白鼠的抗老化作用

有用微生物提取物（EM－X）是由从乳酸菌,酵母菌,兴合成菌,真菌,放线菌等好氧和厌氧菌居中精选出来的有用微生物群（EM）发酵谷鼓和海藻而制成的一种具有显著抗氧化作用的新型健康饮料水,EM－X主要含有40种以上的矿物质,丰富的抗氧化物（类黄酮、黄酮醇、人参皂甙、极精、番茄红素、谷维素、辅酶Q、抗坏血酸、维生素E等）和生物活性物质（烟酰胺单核苷酸,烟酰胺腺膘呤二核苷酸以及肽类和氨基丙酸,谷氨酸等氨基酸）。本研究观察了EM－X在实验动物体内的,抗氧化作用及其对动物老化,应激和免疫机能的影响。结果显示：5％浓度的EM－X能提高半乳糖致衰小鼠血清SOD的活性,降低血清MDA的含量,促进正常小鼠血清溶血素抗体的产生和减轻环磷酰胺对溶血素抗体生成的抢制：提高小鼠腹腔巨噬细胞的吞噬功能,延长小鼠在高温,常压缺氧,负重游泳时的生存时间。说明EM－X具有明显的抗氧化,抗老化,抗应激和免疫增强作用。     

罗汉果多糖对环磷酰胺所致的免疫 抑制小鼠免疫功能的影响

该研究将小鼠随机分成正常组,模型组,罗汉果多糖低、中、高剂量组(25、50、100 mg·kg~(-1))和左旋咪唑组,采用腹腔注射环磷酰胺(20 mg·kg~(-1))建立免疫抑制小鼠模型,连续灌胃给药14 d后,测定各组小鼠的免疫器官指数、廓清指数(K)、吞噬指数(α)、T和B淋巴细胞增殖水平、耳肿胀度、半数溶血值(HC50)以及免疫球蛋白G(IgG)、免疫球蛋白M(IgM)、IL-2、IL-4、IL-6、TNF-α的含量,并观察脾组织病理形态变化,考察罗汉果多糖对免疫抑制小鼠免疫功能的影响。结果表明:罗汉果多糖各剂量组(25、50、100 mg·kg~(-1))均能显著提高免疫抑制小鼠的免疫器官指数、半数溶血值(HC_(50))、B淋巴细胞增殖能力,明显降低耳肿胀度,显著增加IgG、IgM、IL-2、IL-4、IL-6、TNF-α的含量。罗汉果多糖中、高剂量组(50、100 mg·kg~(-1))能显著增强T淋巴细胞增殖能力,明显增加廓清指数(K)、吞噬指数(α)。脾组织病理学观察结果表明,罗汉果多糖可以减轻免疫抑制小鼠脾脏的病理损伤。这表明罗汉果多糖能明显增强环磷酰胺所致免疫抑制小鼠的免疫功能。     

植物乳杆菌JLK0142胞外多糖对RAW264.7巨噬细胞和免疫抑制小鼠的免疫调节作用

【目的】研究植物乳杆菌JLK0142胞外多糖(EPS)对RAW264.7巨噬细胞和免疫抑制小鼠免疫活性的影响。【方法】从植物乳杆菌JLK0142培养液中分离纯化EPS,采用体外细胞培养,测定EPS对巨噬细胞增殖、吞噬活性和一氧化氮(NO)分泌的影响;采用环磷酰胺构建免疫抑制小鼠模型,灌胃不同剂量的EPS,分别测定小鼠脾脏指数、T淋巴细胞增殖活力及血清中IL-2和TNF-α水平。【结果】植物乳杆菌JLK0142胞外多糖在50–800μg/m L浓度范围内能促进正常状态RAW264.7巨噬细胞的增殖,显著提高巨噬细胞的吞噬活性及NO的分泌量;与模型组相比,EPS中、高剂量组小鼠脾脏指数和T淋巴细胞增殖活力显著提高;EPS高剂量组小鼠血清中IL-2和TNF-α含量显著提高。【结论】植物乳杆菌JLK0142胞外多糖能有效提高RAW264.7巨噬细胞的免疫活力,并拮抗环磷酰胺对小鼠免疫功能的抑制作用。     

Biochemical and mass spectrometry recognition of phospholipid–peptide complexes in wheat sprouts extract

Total hydroalcoholic extract of wheat sprouts was treated with 90% cold acetone as a preliminary step directed to separate antioxidant peptides from antioxidant polyphenols. Surprisingly, the addition of acetone causes the formation of a yellow buoyant gelatinous drop that prevailingly contains peptides and phospholipids. In this context, evidences have been presented that support the hypothesis that peptides (and perhaps other active molecules) are complexed with phospholipids. In fact, the MS/MS analysis of some main ions, present in RP HPLC fractions of wheat sprout extract, generates several ions that correspond to molecular weight of phospholipids or phospholipid fragments. Moreover, several ions were detected that correspond to lysophosphatidylcholine or phosphatidylcholine–peptide complexes. The possibility that phospholipids can be complexed with peptides has been discussed in the light of potential involvement in the peptide bioavailability. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.     

胶原蛋白肽对高脂日粮小鼠抗氧化能力和血脂代谢的影响

本文探讨胶原蛋白肽对高脂日粮小鼠抗氧化能力及血脂代谢的影响。40只小鼠随机分为5组(n=8):分别饲喂正常日粮,高脂日粮,添加0.5%和1%胶原蛋白肽及0.1%硫辛酸的高脂日粮。42 d后测定小鼠全血(血清)和组织活性氧(Reactive oxygen species,ROS)水平、丙二醛(Malondialdehyde,MDA)含量、抗氧化酶活力及血脂水平。结果表明:0.5%和1%胶原蛋白肽都可显著降低机体ROS水平及MDA含量(P<0.05),增强抗氧化能力(P<0.05),改善血脂水平(P<0.05)。1%胶原蛋白肽能使机体抗氧化能力及血脂水平恢复到正常水平,0.5%的添加量效果不显著。适量的胶原蛋白肽可有效提高机体抗氧化能力,缓解高脂膳食造成的氧化应激,改善血脂代谢。     

Selected lactic acid bacteria synthesize antioxidant peptides during sourdough fermentation of cereal flours

A pool of selected lactic acid bacteria was used for the sourdough fermentation of various cereal flours with the aim of synthesizing antioxidant peptides. The radical-scavenging activity of water/salt-soluble extracts (WSE) from sourdoughs was significantly (P < 0.05) higher than that of chemically acidified doughs. The highest activity was found for whole wheat, spelt, rye, and kamut sourdoughs. Almost the same results were found for the inhibition of linoleic acid autoxidation. WSE were subjected to reverse-phase fast protein liquid chromatography. Thirty-seven fractions were collected and assayed in vitro. The most active fractions were resistant to further hydrolysis by digestive enzymes. Twenty-five peptides of 8 to 57 amino acid residues were identified by nano-liquid chromatography-electrospray ionization-tandem mass spectrometry. Almost all of the sequences shared compositional features which are typical of antioxidant peptides. All of the purified fractions showed ex vivo antioxidant activity on mouse fibroblasts artificially subjected to oxidative stress. This study demonstrates the capacity of sourdough lactic acid bacteria to release peptides with antioxidant activity through the proteolysis of native cereal proteins.     

In vitro digestive stability of complexes between gliadin and synthetic blocking peptides

Celiac disease is caused by an inappropriate immune response to incompletely digested gluten proteins. We investigated whether synthetic peptides with high affinity to wheat gliadin could be selected with a phage display technique and whether complexes between such peptides and gliadin could sustain gastric and pancreatic digestion. Two synthetic peptides, P61 and P64, were selected because of their high affinity to immobilized gliadin. They were allowed to form complexes with gliadin, whereafter the complexes were subjected to in vitro digestion with gastric and pancreatic enzymes. The digestion products were analyzed with Western blot and RP HPLC. The results showed that both peptides formed stable complexes with intact gliadin and that complexes between gliadin and peptide P64 partly resisted gastrointestinal digestion. The two peptides reduced the binding of serum anti-gliadin IgA antibodies by 12%, and 11.5%, respectively, and the binding of anti-gliadin antibodies of the IgG isotype by 13% and 10%. Thus peptides produced by a phage display technique could interact stably with gliadin partly masking epitopes for antibody binding. A combination of peptides of this kind may be used to block gliadin-immune system interactions.     

Use of an antiserum against deglycosylated human mucins for cellular localization of their peptide precursors: antigenic similarities between bronchial and intestinal mucins

Highly glycosylated regions of mucins, or glycopeptides, were obtained by proteolysis of human bronchial mucins. They were deglycosylated by treatment with a trifluoromethane sulfonic acid/anisole mixture and subsequent solvolysis with anhydrous liquid hydrogen fluoride. The resulting peptides were then used to raise an immune serum in rabbit. This immune serum was used to localize the peptide precursors of human respiratory mucins within bronchial cells, using an immunohistochemical method. Two main patterns of labeling were observed in the goblet cells: the entire cytoplasm of some goblet cells was immunoreactive, whereas in other cells the labeling was concentrated around the nucleus. In the respiratory mucous glands, the labeling was localized around or below the nucleus. The serous cells were not stained. Similar labeling was observed in human colon goblet cells. This immune serum seems to be specific for mucin-secreting cells and has a strong affinity for the perinuclear region of these cells.     

Breaking immune tolerance to the prion protein using prion protein peptides plus oligodeoxynucleotide-CpG in mice

The absence of a detectable immune response during transmissible spongiform encephalopathies is likely due to the fact that the essential component of infectious agents, the prion protein (PrP), is a self Ag expressed on the surface of many cells of the host. To overcome self-tolerance to PrP, we used 30-mer PrP peptides previously shown to be immunogenic in Prnp(-/-) mice, together with CFA or CpG-oligodeoxynucleotides (CpG) in IFA. Generation of anti-PrP T and B cell responses was analyzed in the spleen, lymph nodes, and serum of immunized C57BL/6 wild-type mice. Immunization with PrP peptides emulsified in CFA did not trigger an immune response to PrP. When CpG were used, vaccination with peptides P143-172 and P158-187 generated IFN-gamma-secreting splenic T cells, and only P158-187 significantly stimulated IL-4-secreting T cells. Both peptides induced few Ab-producing B cells, and low and variable serum Ab titers. In contrast, immunization with peptide P98-127 did not induce significant levels of T cell responses but elicited specific peptide Abs. T cell epitope mapping, performed using 15-mer peptides covering PrP segment 142-182, revealed that an immunogenic motif lies between positions 156 and 172. These results demonstrate that T and B cell repertoires against PrP can be stimulated in C57BL/6 when adjuvant of the innate immunity such as CpG, but not CFA, is added to PrP peptides, and that the pattern of immune responses varies according to the epitope.     

Purification and Identification of Pine Nut (Pinus yunnanensis Franch.) Protein Hydrolysate and Its Antioxidant Activity in Vitro and in Vivo

In this study, the pine nut (Pinus yunnanensis Franch.) protein was hydrolyzed by alkaline protease and trypsin to prepare pine nut protein hydrolysate (PNPH). The chemical, intracellular and in vivo antioxidant capacity of PNPH were evaluated. PNPH owned the ability of scavenging free radicals, and it could protect the HepG2 cells from oxidative damage by preserving cell viability. Moreover, PNPH could reduce the malondialdehyde (MDA) content and improved the superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in serum, heart and liver of aging mice induced by D-galactose. Further, the PNPH was stepwise purified and identified, and 15 peptides were identified from purified fraction in PNPH. The three-dimension structures of identified peptides were predicted. Among all identified peptides, peptide 3, 7, 8 and 11 were presumed to possess good antioxidant activity. Overall, PNPH and purified peptides isolated from PNPH have potential application prospects in the field of natural antioxidants and anti-aging functional foods.     

Comparison of cellular and humoral responses to recombinant protein and synthetic peptides of exon2 region of Plasmodium falciparum erythrocyte membrane protein1 (PfEMP1) among malaria patients from an endemic region

Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) expressed on the surface of parasitized red blood cells (PRBCs) mediate adhesion of PRBCs to host vascular endothelial receptors and is considered responsible for pathogenesis of severe P. falciparum malaria. The present study was undertaken to measure cellular immune responses and serum antibody responses against recombinant exon2 protein, the most conserved region of PfEMP1, and its synthetic peptides. T cell recognizing this domain could provide universal help to B cells in recognizing variant epitopes located in the extracellular region of PfEMP1. Human peripheral blood mononuclear cells from malaria-exposed immune adults (IA), malaria patients with varying severity, and malaria unexposed healthy donors were stimulated with recombinant exon2 protein and six synthetic peptides from its sequence to estimate the proliferative, IFN-gamma, and IL-4 responses. Antibody responses against these synthetic peptides and exon2 protein were also studied. Positive proliferative, IFN-gamma, and IL-4 responses in IA group each were 60% with recombinant exon2 protein and 27-47% with different synthetic peptides. Antibody recognition was observed in 67% with exon2 and between 40 and 53% with different peptides. In malaria patients, frequency and magnitude of proliferative response, IL-4 concentration, and antibody recognition were far less than immune adults but IFN-gamma response was almost similar. Proportion of positive responders and the magnitude of response to synthetic peptides were low. Also, there was no consistency in response of different peptides towards proliferative, cytokine, and antibody responses in IA and malaria patient groups except for peptide 1. We presume peptide 1 is a potential vaccine candidate and different cocktails containing peptide 1 are being evaluated for their T cell immunogenicity.     

Purification of soluble HLA class I complexes from human serum or plasma deliver high quality immuno peptidomes required for biomarker discovery

Soluble human leukocyte antigen class I (sHLA)‐peptide complexes have been suggested to play a role in the modulation of immune responses and in immune evasion of cancer cells. The set of peptides eluted from sHLA molecules could serve as biomarker for the monitoring of patients with cancer or other conditions. Here, we describe an improved sHLA peptidomics methodology resulting in the identification of 1816 to 2761 unique peptide sequences from triplicate analyses of serum or plasma taken from three healthy donors. More than 90% of the identified peptides were 8–11mers and 74% of these sequences were predicted to bind to cognate HLA alleles, confirming the quality of the resulting immunopeptidomes. In comparison to the HLA peptidome of cultured cells, the plasma‐derived peptides were predicted to have a higher stability in complex with the cognate HLA molecules and mainly derived from proteins of the plasma membrane or from the extracellular space. The sHLA peptidomes can efficiently be characterized by using the new methodology, thus serving as potential source of biomarkers in various pathological conditions.