RP-HPLC法测定蜂王浆水溶性蛋白及其相关产物对ACE的抑制作用

采用反相高效液相色谱(RP-HPLC),测定蜂王浆水溶性蛋白(WSPs)、WSPs的纯化蛋白1(MRJP1)和2(MRJP2)、WSPs的酶解产物(P-WSPs、T-WSPs和PT-WSPs)及从WSPs和酶解产物中分离到的不同肽段(>3 ku,1～3 ku和<1 ku)等对血管紧张素转换酶(ACE)的抑制作用。结果表明,WSPs、MRJP1和MRJP2等水溶性蛋白本身对ACE抑制作用很弱,而它们的酶解产物对ACE的抑制作用却大大增强了,其IC50值分别为,P-WSPs:0.262 mg/mL;T-WSPs:0.870 mg/mL;PT-WSPs:0.046 mg/mL。在WSPs和酶解产物的膜分离肽段中,分子质量小于1 ku的肽段对ACE具有非常强的抑制作用。     

Regulation of inducible nitric oxide synthase by arabinoxylans with molecular characterisation from wheat flour in cultured human monocytes

The immunomodulatory activity of the arabinoxylans (AXs) extracts from cereal sources has been reported to impart health benefits in terms of immune enhancement. This study investigated the effect of enzymatic extraction on extraction yield and structure of AXs from wheat flour pentosan fraction. Under the optimised conditions, the extraction yield of AXs reached up to 81.25%. Furthermore, the study determined whether water‐extracted AXs (WEAXs) and enzyme‐extracted AXs (E‐WEAXs) from wheat flour were able to differentially stimulate nitric oxide (NO) secretion through increased levels of inducible nitric oxide synthase (iNOS) in human U937 monocytes. The results indicated that AXs concomitantly induced (P < 0.05) both NO and iNOS productions in U937 monocytes compared to untreated cells. Compared with WEAXs, E‐WEAXs resulted in a higher proportion of low Mw (1–10 KDa) AXs (49.51% vs. 19.11% in WEAXs), a higher A/X ratio (0.83 vs. 0.48 in WEAXs) and a higher yield (12.83 ± 0.35% vs. 7.54 ± 0.47% in WEAXs). Moreover, E‐WEAXs induced significantly (P < 0.05) greater NO and iNOS production per million viable cells (61.8 ± 2.7 μm and 42.41 ± 3.83 ng respectively) than WEAXs (51.6 ± 2.6 μm and 33.46 ± 1.48 ng, respectively). The findings suggest AXs may heighten innate immune activity in the absence of infection or disease through an iNOS‐mediated stimulation of NO production. The immunomodulatory activity of the wheat‐derived AXs was enhanced by enzyme treatment, with low Mw and high A/X ratio associated with elevated NO/iNOS levels in human monocytes compared to water extraction.     

蜂王浆冻干粉对HepG2细胞葡萄糖消耗作用及对糖尿病小鼠降糖作用的实验研究

目的:研究蜂王浆冻干粉体内外降糖作用。方法:采用与人肝细胞表型相似的HepG2细胞,检测24h后培养液中葡萄糖的消耗量,用MTT法监测细胞增殖的情况;以四氧嘧啶造成小鼠糖尿病模型,观察蜂王浆对糖尿病模型小鼠的降糖作用。结论:蜂王浆冻干粉可使高糖状态下HepG2细胞的葡萄糖消耗量增加,对胰岛素刺激的HepG2细胞的葡萄糖消耗量增加有协同作用;能降低四氧嘧啶所致糖尿病小鼠的血糖。     

一氧化氮对绿熟和粉红期番茄采后抗氧化相关酶的影响

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Effect of nitric oxide on reactive oxygen species and antioxidant enzymes in kiwifruit during storage

BACKGROUND: The accumulation of reactive oxygen species (ROS) in kiwifruit can cause oxidative damage during storage. Little research has been carried out on the effects of nitric oxide (NO) on oxidative damage to kiwifruit. Therefore the aim of the present study was to evaluate the ability of 0.5, 1 and 2 µmol L^?1 NO aqueous solutions to alleviate oxidative damage to kiwifruit during storage. RESULTS: The most marked effect was obtained with 1 µmol L^?1 NO solution, which significantly reduced the accumulation of malondialdehyde, superoxide and hydrogen peroxide, delayed the decrease in vitamins C and E, maintained the content of soluble solids, inhibited the activity of lipoxygenase and peroxidase and increased the activity of superoxide dismutase and catalase in kiwifruit during storage. The 0.5 µmol L^?1 NO solution was too weak to significantly affect the content of ROS and the activity of enzymes. However, treatment with 2 µmol L^?1 NO solution promoted the accumulation of ROS, decreased the activity of antioxidant enzymes and accelerated peroxidation in kiwifruit during storage. CONCLUSION By increasing the activity of antioxidant enzymes and maintaining the content of vitamins C and E, treatment with 1 µmol L^?1 NO aqueous solution could protect kiwifruit against oxidative damage caused by ROS during storage. Copyright © 2008 Society of Chemical Industry     

Effects of nitric oxide on the alleviation of postharvest disease induced by Penicillium italicum in navel orange fruits

The present study evaluated the effects of 15 μL L^-1 nitric oxide (NO) on the fruit defence response of ‘Newhall’ navel orange. The decay rate of NO-treated navel orange fruits was significantly lower than that of control fruits during storage at 20 °C storage (P < 0.05). Treatment with NO suppressed the increase in disease incidence and lesion area in orange fruits inoculated with Penicillium italicum (P. italicum); significantly increased the activities of phenolic metabolism-associated enzymes and pathogenesis-related (PR) proteins, including polyphenoloxidase (PPO), phenylalanine ammonia-lyase (PAL), β-1,3-glucanase (GLU) and chitinase (CHT); and enhanced the activities of key enzymes, including 4-coumarate: CoA ligase (4CL), cinnamate-4-hydroxylase (C4H) and chalcone isomerase (CHI) in the phenylpropanoid pathway. The contents of total phenolics, flavonoids and lignin were also higher in NO-treated fruits than in control fruits. The findings suggest that exogenous NO could induce disease resistance against P. italicum in navel orange fruits.     

外源NO对伽师瓜AOX基因克隆表达及抗氰呼吸的影响

为了探究外源一氧化氮(nitric oxide,NO)熏蒸处理对伽师瓜(Cucumis melo L.)采后贮藏过程中AOX基因表达及抗氰呼吸途径的影响,以伽师瓜为试材,采用外源60μL/L NO熏蒸3 h,以不充入NO气体作为对照,在(5±0.5)℃条件下贮藏49 d。根据甜瓜基因组数据库,通过EST设计引物,克隆获得伽师瓜AOX基因全长序列。得到的基因片段同其他物种的AOX基因具有高度的同源性,命名为Cm AOX。通过拼接获得AOX基因的c DNA全长序列,基因c DNA全长为1300 bp,开放阅读框架为1042 bp,拟编码346个氨基酸,预测分子量为39606.6 Da,等电点为9.00。该基因已在Gene Bank登录,登录号为:KM273124。通过荧光定量分析及抗氰呼吸速率的测定表明,经60μL/L NO处理果实的Cm AOX的表达量和抗氰呼吸速率明显高于对照果实。说明NO处理对伽师瓜采后贮藏过程中抗氰呼吸途径的影响可能与其调控AOX基因的表达密切相关。      

Effects of exogenous nitric oxide on contents of soluble sugars and related enzyme activities in 'Feicheng' peach fruit

BACKGROUND: Sugar content is one of the main characteristics related to the quality of fruit. Research confirms that nitric oxide (NO) involves a physiological process and prolongs the storage life of fruit. However, little attention has been paid to the effects of NO on sugar metabolism in fruit during storage. In this study, the effect of different concentrations (0, 10, 30 µmol L^?1) of exogenous NO treatment on sugar content and related enzyme activities in ‘Feicheng’ peach fruit was investigated during storage (0–12 days after harvest) at room temperature (25 °C). RESULTS: Results showed that the decrease of firmness and accumulation of sugar and acid:sugar ratio in peach fruit during storage were significantly inhibited by treatment with 10 µmol L^?1 NO. Treatment with 10 µmol L^?1 NO could promote fructose and glucose metabolism during the first 4 days of storage, and increase the content of sucrose and the activities of sorbitol dehydrogenase, sorbitol oxidase and sucrose phosphate synthase in peach fruit during storage. However, acid invertase activity from 8 to 12 days of storage and neutral invertase activity during the first 4 days of storage were inhibited by treatment with 10 µmol L^?1 NO. At the same time, treatment with 10 µmol L^?1 NO inhibited sucrose synthase (SS) activity in decomposition during storage and SS activity in synthesis from 8 to 12 days of storage. CONCLUSION: Treatment with 10 µmol L^?1 NO had a significant impact on content of soluble sugars and related enzyme activities in ‘Feicheng’ peach fruit during storage (0–12 days) at room temperature (25 °C). Copyright © 2011 Society of Chemical Industry     

Inhibition of browning on the surface of peach slices by short-term exposure to nitric oxide and ascorbic acid

The effect of 0.2% ascorbic acid (AA), 5 μM nitric oxide (NO), and the simultaneous use of 0.2% AA and 5 μM NO solutions on inhibiting surface browning of fresh-cut peach slices stored at 10 °C and RH 95% was investigated. The browning index, relative leakage rate, microstructure, total phenol content, and activity of the phenol metabolism-associated enzymes phenylalanine ammonia lyase (PAL), polyphenol oxidase (PPO) and peroxidase (POD) were evaluated. The results indicate that treatment with 0.2% AA, 5 μM NO and simultaneous use of 0.2% AA and 5 μM NO resulted in higher total phenol content, inhibition of PPO and POD activity, reduced membrane permeability and protection of cell microstructure to maintain compartmentation between enzymes and their substrates. In addition, NO increased PAL activity. The causes of inhibition in the browning of peach slices by NO are discussed.     

发酵乳杆菌HCS08-005耐逆性及对体外细胞免疫调节作用的研究

目的 研究发酵乳杆菌(Lactobacillus fermentum) HCS08-005耐逆性及对体外细胞的免疫调节作用。方法 考察发酵乳杆菌HCS08-005的耐酸耐胆盐能力,并应用发酵乳杆菌HCS08-005细胞裂解物,处理小鼠单核巨噬细胞RAW264.7和小鼠脾脏细胞,用酶联免疫吸附测定试剂盒检测各类炎症因子包括肿瘤坏死因子-α (tumor necrosis factor-α,TNF-α)、白细胞介素-2 (inter-leukin-2,IL-2)、白细胞介素-12 (inter-leukin-12,IL-12)、γ干扰素(interferon-γ,IFN-γ)的表达水平。结果 显示发酵乳杆菌HCS08-005有较好的耐逆性,能够耐受酸和胆盐环境到达肠道发挥作用。不同浓度的发酵乳杆菌HCS08-005细胞裂解物对小鼠脾脏细胞和巨噬细胞分泌炎症因子均有极显著影响(P<0.01),在质量浓度为100 μg/g时,IL-2分泌量为421.49 pg/g,TNF-α分泌量为161.23 pg/g,IFN-γ分泌量为846.14 pg/g,IL-12分泌量为12.88 pg/g,因子水平极显著提高(P<0.01)。结论 在体外细胞试验中,发酵乳杆菌HCS08-005有较好的耐逆性,对体外细胞有免疫调节作用。     

蒲公英红枣汁对D-半乳糖致衰老模型雌性大鼠抗氧化抗炎作用的研究

目的 研究蒲公英红枣汁对D-半乳糖致衰老模型雌性大鼠体内抗氧化、抗炎作用的影响。方法 50只雌性大鼠随机分为对照组、模型组、蒲公英红枣汁低(5 mL/kg)、中(10 mL/kg)、高(20 mL/kg)剂量组。对照组以外的大鼠腹腔注射D-半乳糖500 mg/(kg·d),连续6周建立衰老模型。然后蒲公英红枣汁灌胃干预30 d,对照组与模型组以同样方法给予等体积蒸馏水。检测各组大鼠血清和卵巢组织丙二醛(malondialdehyde,MDA)含量和超氧化物歧化酶(superoxide dismutase,SOD)、血清谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)、过氧化物酶(catalase, CAT)活性、谷胱甘肽(glutathione, GSH)含量等抗氧化相关指标;测定大鼠血清中白细胞介素1β(interleukin-1β,IL-1β)、白细胞介素-6(interleukin-6,IL-6)、肿瘤坏死因子(tumornecrosis factor-α, TNF-α)、诱导型一氧化氮合酶(inducible nitric oxide synth...     

重楼叶多糖改善D-半乳糖衰老模型小鼠脾脏免疫功能和抗氧化能力

采用D-半乳糖注射诱导衰老模型,探讨了重楼叶多糖（PPLPs）对小鼠脾脏免疫功能和抗氧化的影响。分别对小鼠D-半乳糖、D-半乳糖和PPLPs、D-半乳糖和VC以及生理盐水处理,持续42 d。结果显示:与模型组相比,灌胃PPLPs或VC均能显著增加小鼠脾脏指数（p<0.05）,显著上调脾脏免疫相关基因（T-bet、GATA、IFN-γ、IL-2、TNF-α、IL-4和IL-10）m RNA表达水平（p<0.05）,也显著增强了脾脏总超氧化物歧化酶（T-SOD）、铜锌超氧化物歧化酶（Cu Zn-SOD）、谷胱甘肽过氧化物酶（GSH-Px）和过氧化氢酶（CAT）活性（p<0.05）;同时,灌胃PPLPs或VC显著降低了脾脏丙二醛（MDA）含量（p<0.05）。结果表明,PPLPs可增强脾脏免疫功能并提高小鼠的抗氧化活性。