茶多酚对大鼠血管紧张素Ⅰ转换酶(ACE)活性的影响

研究茶多酚对大鼠血管紧张素Ⅰ转换酶(angiotensin Ⅰ converting enzyme,ACE)活性的影响.血管紧张素Ⅰ在ACE的作用下,通过脱去C端His-Leu二肽,转化为有生物活性的血管紧张素Ⅱ,从而产生强升压作用.通过体外试验和体内试验研究茶多酚对大鼠ACE活性的影响效应.试验结果表明,随着茶多酚摄入量的增加(45 mg/kg,90 mg/kg,180 mg/kg),ACE活性显著降低(84.43+4.59 u/μl,75.17±6.85 u/μl,60.19±8.62 u/μl,P＜0.05)说明茶多酚对大鼠ACE有抑制作用,从而有可能起到降低血压的作用.     

茶多酚对大鼠血管紧张素I转换酶(ACE)活性的影响

研究茶多酚对大鼠血管紧张素Ⅰ转换酶(angiotensinⅠconvertingenzyme,ACE)活性的影响。血管紧张素Ⅰ在ACE的作用下,通过脱去C端His-Leu二肽,转化为有生物活性的血管紧张素Ⅱ,从而产生强升压作用。通过体外试验和体内试验研究茶多酚对大鼠ACE活性的影响效应。试验结果表明,随着茶多酚摄入量的增加(45mg/kg,90mg/kg,180mg/kg),ACE活性显著降低(84.43±4.59u/μl,75.17±6.85u/μl,60.19±8.62u/μl,P<0.05)说明茶多酚对大鼠ACE有抑制作用,从而有可能起到降低血压的作用。     

Affinity Purification of Angiotensin Converting Enzyme Inhibitory Peptides from Wakame (Undaria Pinnatifida) Using Immobilized ACE on Magnetic Metal Organic Frameworks

Angiotensin-I-converting enzyme (ACE) inhibitory peptides derived from marine organism have shown a blood pressure lowering effect with no side effects. A new affinity medium of Fe₃O₄@ZIF-90 immobilized ACE (Fe₃O₄@ZIF-90-ACE) was prepared and used in the purification of ACE inhibitory peptides from Wakame (Undaria pinnatifida) protein hydrolysate (<5 kDa). The Fe₃O₄@ZIF-90 nanoparticles were prepared by a one-pot synthesis and crude ACE extract from pig lung was immobilized onto it, which exhibited excellent stability and reusability. A novel ACE inhibitory peptide, KNFL (inhibitory concentration 50, IC₅₀ = 225.87 μM) was identified by affinity purification using Fe₃O₄@ZIF-90-ACE combined with reverse phase-high performance liquid chromatography (RP-HPLC) and MALDI-TOF mass spectrometry. Lineweaver–Burk analysis confirmed the non-competitive inhibition pattern of KNFL, and molecular docking showed that it bound at a non-active site of ACE via hydrogen bonds. This demonstrates that affinity purification using Fe₃O₄@ZIF-90-ACE is a highly efficient method for separating ACE inhibitory peptides from complex protein mixtures and the purified peptide KNFL could be developed as a functional food ingredients against hypertension.     

Angiotensin-I Converting Enzyme (ACE) Inhibitory and Anti-Hypertensive Effect of Protein Hydrolysate from Actinopyga lecanora (Sea Cucumber) in Rats

Food protein hydrolysates are known to exhibit angiotensin converting enzyme (ACE) inhibitory properties and can be used as a novel functional food for prevention of hypertension. This study evaluated the ACE inhibitory potentials of Actinopyga lecanora proteolysate (ALP) in vivo. The pre-fed rats with ALP at various doses (200, 400, 800 mg/kg body weight) exhibited a significant (p ≤ 0.05) suppression effect after inducing hypertension. To determine the optimum effective dose that will produce maximal reduction in blood pressure, ALP at three doses was fed to the rats after inducing hypertension. The results showed that the 800 mg/kg body weight dose significantly reduced blood pressure without noticeable negative physiological effect. In addition, there were no observable changes in the rats’ heart rate after oral administration of the ALP. It was concluded that Actinopyga lecanora proteolysate could potentially be used for the development of functional foods and nutraceuticals for prevention and treatment of hypertension.     

Broken Rice as a Potential Functional Ingredient with Inhibitory Activity of Renin and Angiotensin-Converting Enzyme(ACE)

Plant Foods for Human Nutrition - The aim of this work was to evaluate the ability of broken rice, an underutilized industrial by-product, as a potential functional and health promoting ingredient....     

羧基化壳寡糖络合碘（CCOS-I）对水稻纹枯病菌的抑制作用及机理初讨

为明确羧基化壳寡糖络合碘（CCOS-I）对水稻纹枯病的防治作用,以 20%井冈霉素可湿性粉剂为对照药剂,测定 CCOS-I 对水稻纹枯病菌的室内抑菌效果和田间防效,以及对超氧化物歧化酶（superoxidedismutase,SOD）、叶片过氧化物酶（peroridase,POD）、多酚氧化酶（polyphenol oxidase,PPO）、苯丙氨酸解氨酶（phenylalanine ammonia-lyase,PAL）和 β-1,3-葡聚糖酶（β-1,3-glucanase）等相关防御酶活性的影响。结果表明：羧基化壳寡糖络合碘对该病菌抑制效果明显,经室内毒力测定,其 EC50 值 12.22 mg/L,明显高于对照药剂 20%井冈霉素粉剂。田间药效试验结果表明,在水稻第 3 次用药后 14 d,100 g/hm2 的羧基化壳寡糖络合碘防效达到 80.66%,与井冈霉素有效剂量 150 g/hm2 的效果相当,优于同剂量井冈霉素处理。CCOS-I 在试验剂量范围内对水稻纹枯病有很好的防治作用,且对水稻生长无任何药害现在发生,可以诱导水稻相关防御酶活性提高,适用于水稻纹枯病的防治,具有一定的开发推广价值。     

低温胁迫对茶树抗氧化酶活性的影响

以白鸡冠F1代新品系（0306I、0306F、0306D）及黄旦的扦插苗为试验材料,测定低温（0℃）胁迫下茶树抗氧化酶活性的变化。结果表明,低温下各品种（系）叶片电导率、过氧化氢及丙二醛含量都显著增加,其中0306F与0306D增加幅度明显大于黄旦与0306I;谷胱甘肽还原酶（GR）、抗坏血酸过氧化物酶（APX）、过氧化物酶（POD）与超氧化物岐化酶（SOD）活性都显著增加,其中黄旦与0306I低温下GR、APX、POD、SOD增加幅度远大于品系0306D与0306F。低温下单脱氢抗坏血酸还原酶（MDAR）、脱氢抗坏血酸还原酶（DHAR）、过氧化氢酶（CAT）、抗坏血酸（ASC）与谷胱甘肽（GSH）活性显著下降,其中0306F与0306D品系叶片的MDAR与CAT低温下下降幅度远大于黄旦与0306I。回归分析发现,叶片双氧水含量与APX（y=601.8-59.1x）及CAT（y=5.45-0.77x）活性呈负相关,电导率与ASC（y=7.45-10.35x）也呈负线性相关。以上结果表明,茶树品种（系）0306F与0306D抗寒性弱于0306I与黄旦。     

高温对阿里山潜蝇茧蜂体内保护酶系活性的影响

采用分光光度法测定不同温度条件下(29、32、35、38、41℃)阿里山潜蝇茧蜂[Fopius arisanus (Sonan)]幼虫、蛹和成蜂体内保护酶系活性的变化.结果表明:(1)经不同高温处理后,阿里山潜蝇茧蜂各虫态体内过氧化氢酶(Catalase,CAT)活性均明显高于对照组,38℃为幼虫、蛹和雌蜂体内CAT清除H2O2的最适温度.同一处理温度下,幼虫体内CAT活性高于蛹,雄蜂体内CAT活性高于雌虫.(2)热胁迫处理后,雌雄蜂体内过氧化物酶(Peroxidase,POD)活性均高于对照,且雄蜂体内POD活性高于雌蜂.幼虫、蛹和雌蜂体内POD活性随温度的升高呈“M”形变化趋势,分别在35、38、35℃时达最大值.(3)阿里山潜蝇茧蜂高温暴露后,幼虫和蛹体内超氧化物歧化酶(Superoxide dismutase,SOD)活性均在35℃时达最大值,雌雄蜂体内SOD活性均明显高于对照,分别在35、32℃时活性达到最大.     

Kinetics of the Inhibition of Renin and Angiotensin I Converting Enzyme by Polar and Non-polar Polyphenolic Extracts of <Emphasis Type="Italic">Vernonia Amygdalina</Emphasis> and <Emphasis Type="Italic">Gongronema Latifolium</Emphasis> Leaves

The aim of this study was to determine the in vitro modulation of the renin-angiotensin system by polyphenolic extracts and fractions of two green leafy vegetables, Vernonia amygdalina (VA) and Gongronema latifolium (GL), that are used for food and medicinal purposes. An 80% acetone extract of each leaf was fractionated on silicic acid-packed column to give two main fractions: acetone eluate (flow-through) and ethanol eluate (column-bound), that consist mostly of chlorophyllic and non-chlorophyllic fractions, respectively. Column fractionation resulted in polyphenolic fractions that displayed higher potency against angiotensin converting enzyme (ACE) and renin than the crude acetone extracts; generally, the chlorophyllic fraction was more active than the non-chlorophyllic fraction. ACE-inhibitory activity was significantly higher (p < 0.05) for the chlorophyllic fraction of VA than GL, with IC₅₀ values of 0.207 and 0.413 mg/ml, respectively. Similarly, the chlorophyllic fraction of VA had significantly higher (p < 0.05) renin inhibition than GL, with IC₅₀ values of 0.172 and 0.513 mg/ml, respectively. Kinetics studies showed that the chlorophyllic fractions of VA and GL exhibited mostly mixed-type ACE and renin inhibitions. We concluded that the hydrophobic nature of the chlorophyllic fraction may have contributed to the increased interaction with enzyme protein and inhibition of activities of ACE and renin.     

Nitrate-Induced Inhibition of Root Nodule Formation and Nitrogenase Activity in the Peanut (Arachis hypogaea L.)

Summary

The effect of nitrate in the culture solution (0.7, 3.5, 7.0, and 14.0 mM N) on the growth, root nodule formation and nitrogenase activity of the peanut (cv. chico) inoculated with Bradyrhizobium sp. was examined at early developmental stages. The amount of nitrogen derived from fixation and its percentage to total nitrogen in the nitrate-fed plant were evaluated using ¹⁵N labeled nitrate. The dry weight and total nitrogen content of the plant at 40 days after transplanting (day 40) varied with the concentration of nitrate in the culture solution. Both of them were higher in the plants grown in the presence of nitrate at the concentrations above 0.7 mM. On the other hand, the number and fresh weight of nodules, and acetylene reduction activity per plant were the lowest in the presence of nitrate at 14.0 mM, relatively high at 0.7 mM, and the highest at 3.5 mM. The proportion of N derived from atmosphere to total nitrogen in the plants examined at days 18 and 33 was 23–31% in the presence of nitrate at 3.5 and 14.0 mM. However, the proportion examined at day 48 was as high as 57–58% at 3.5 mM, and it was only 22–24% at 14.0 mM.     

茶黄素对糖尿病大鼠肾小球系膜细胞p38丝裂原活化蛋白激酶及细胞外基质合成的影响

探讨茶黄素对糖尿病肾病大鼠肾小球系膜细胞p38丝裂原活化蛋白激酶(p38MAPK)及细胞外基质(ECM)合成的影响。分别以正常糖(NG)、高糖(HG)、糖基化终产物(AGE)及过氧化氢(H2O2)孵育大鼠肾小球系膜细胞,Western Blot检测系膜细胞中p38MAPK和转化生长因子-β(TGF-β)蛋白表达,酶联免疫吸附实验(ELISA)检测细胞培养液中细胞外基质成分纤维连接蛋白(FN)、Ⅳ型胶原(Col Ⅳ)及层黏连蛋白(LN)的含量。结果显示HG、AGE和H2O2能明显诱导p38MAPK磷酸化和TGF-β蛋白表达增加而导致细胞外基质的积聚,茶黄素能明显抑制p38MAPK的磷酸化活性和TGF-β蛋白表达及减少细胞外基质的积聚。提示茶黄素可通过调节p38MAPK信号转导通路而减少细胞外基质的合成,延缓糖尿病肾小球肥大和肾小球硬化。     

细菌性条斑病侵染后普通野生稻与栽培稻杂交后代保护酶活性的变化

以抗水稻细菌性条斑病（简称细条病）的普通野生稻 DY3 和感病轮回亲本 9311 组合构建了 BC2F2 群体, 分蘖期用针刺法人工接种广西细菌性条斑病菌优势致病型菌株 JZ28, 选取其中的 1、 3、 5、 7、 9 级植株为材料,在孕穗期接种第 2 次, 研究接种细条病后水稻叶片防御酶活性的变化动态及其与抗病性的关系。 结果表明： 高抗病 1 级与高感病 9 级材料的苯丙氨酸解氨酶（PAL）、 超氧化物歧化酶（SOD）、 过氧化氢酶（CAT）的活性和丙二醛（MDA）含量与对照亲本时间动态变化趋势相似, 而过氧化物酶（POD）活性变化不一致; 不同抗病等级之间,苯丙氨酸解氨酶活性和过氧化氢酶活性在极端抗感材料之间差异显著, 超氧化物歧化酶、 过氧化物酶活性和丙二醛含量差异不显著。     

栽培稻杂交后代保护酶活性的变化

以抗水稻细菌性条斑病（简称细条病）的普通野生稻DY3和感病轮回亲本9311组合构建了BC2F2群体．分蘖期用针刺法人工接种广西细菌性条斑病菌优势致病型菌株JZ28,选取其中的1、3、5、7、9级植株为材料,在孕穗期接种第2次,研究接种细条病后水稻叶片防御酶活性的变化动态及其与抗病性的关系。结果表明：高抗病1级与高感病9级材料的苯丙氨酸解氨酶（PAL）、超氧化物歧化酶（SOD）、过氧化氢酶（CAT）的活性和丙二醛（MDA）含量与对照亲本时间动态变化趋势相似,而过氧化物酶（POD）活性变化不一致;不同抗病等级之间,苯丙氨酸解氨酶活性和过氧化氢酶活性在极端抗感材料之间差异显著．超氧化物歧化酶、过氧化物酶活性和丙二醛含量差异不显著．     

茶树叶绿素酶活性的变化研究

对茶树中叶绿素酶活性的变化进行了研究,结果显示,叶绿素酶活性从7：00~16：00之间逐渐下降,之后从16：00~19：00又开始有升高的趋势;各季茶树新梢中,春茶新梢叶绿素酶活性最高,夏茶新梢次之,秋茶新梢的酶活性最低;在茶树不同部位,叶绿素酶活性由高到低的顺序为：芽>第1叶>第2叶>第3叶>老叶>嫩茎;在鲜叶摊放的过程中（摊放时间6h）,叶绿素酶活性先升高后降低,之后大幅度升高;8个适制绿茶品种的酶活性,以福云6号的酶活性最高,其次是福鼎大毫茶、福鼎大白茶、鄂茶1号、平阳特早茶、乌牛早,迎霜和龙井43的酶活性最低;茶园中60%和80%的遮光率都能使叶绿素酶活性下降。     

Inhibition of hepatic microsomal NADPH-cytochrome C (P-450) reductase activity in gari-fed rats

NADPH-cytochrome c (P-450) reductase activities were measured in liver microsomes prepared from male albino rats (110–150 g) fed control and (35% w/w) gari (a dried cassava product) based diets for 8 weeks and sacrificed at intervals of 1, 3, 5, and 8 weeks. After an initial increase (2-fold) in NADPH oxidation in the first week, the gari diet consistently produced marked decreases in theK _m andV _max values for NADPH oxidation and cytochrome C reduction. Inhibition of cytochrome C reduction was consistently greater than that of NADPH oxidation. Inhibition was generally not dependent on duration of gari feeding. The site of inhibition of electron-transfer was probably between the reduced prosthetic groups (FAD and FMN) and cytochrome C (P-450).     

玉米新改良群体多酚氧化酶活性变化

选用36份新种质合成相互轮回选择的2个基础群体(NRRSPⅠC0和NRRSPⅡC0)及常规的6个玉米优势群,测定多酚氧化酶(PPO)活性,探讨其利用前景。结果表明,Tan-HzC5酶活性最高,抗病性最好,且Tan-HzC5、NRRSPⅡC0与ReidC2的PPO活性处于同一较高水平;Luda、PFC5的活性最低,与前三者差异极显著;Pn6C4、NRRSPⅠC0和Lan.C2居中。NRRSPⅡC0与NRRSPⅠC0田间表现高抗玉米大斑病和小斑病,Luda高度感病。PPO活性高低与田间抗感病害的试验结果相吻合。     

冬小麦lncRNA1808调控PPP限速酶（Ta6PGDH）抗寒应答研究

为探索lncRNA1808调控Ta6PGDH应答寒胁迫的机制,以冬小麦品种东农冬麦1号（Dn1）为材料,应用生物信息学分析了lncRNA1808和Ta6PGDH的生物学特性和功能,预测了lncRNA1808-Ta6PGDH互作关系和共表达趋势;应用real-time PCR鉴定小麦分蘖节和叶片的lncRNA1808和Ta6PGDH寒胁迫下表达谱变化。结果显示,lncRNA1808为lncRNA,不具备编码能力,富含稳定的茎环结构;lncRNA1808与Ta6PGDH的启动子序列含多种响应环境因子的顺式作用元件;预测lncRNA1808-Ta6PGDH互作并协同共表达;Dn1分蘖节和叶片的lncRNA1808和Ta6PGDH的表达谱与协同共表达分析一致,表达趋势上调。本研究初步揭示了冬小麦lncRNA1808调控PPP限速酶Ta6PGDH的抗寒应答机制。     

Chronic Aerobic Exercise Decreases Lectin-Like Low Density Lipoprotein (LOX-1) Receptor Expression in Heart of Diabetic Rat

Background:

Overexpression of lectin-like low density lipoprotein (LOX-1) receptor plays an important role in hyperglycemia-induced vascular complications such as atherosclerosis. Based on the beneficial effects of exercise on preventing cardiovascular complications of diabetes, we aimed to examine the protective effects of aerobic exercise on expression of LOX-1 receptor and production of free radicals in the heart of diabetic rats.

Methods:

Four groups of rats were used: (n = 5 per group): sedentary normal, trained normal, sedentary diabetes and trained diabetes. Diabetes was induced by a single intraperitoneal injection of streptozotocin (50 mg/kg). The exercise protocol was consisted of swimming 30 min/day, 5 days/week for eight weeks. Plasma glucose was evaluated at initiation, weeks 4 and 8 of experiment. At the end of experiment, rats were sacrificed and the heart was removed for determination of nitrate, malondialdehyde, and LOX-1 gene expression.

Results:

In normal non-diabetic rats, the blood glucose level was <150 mg/dl; however, the induction of diabetes resulted in levels more than >400 mg/dl. Gene expression of LOX-1 was increased in the heart of diabetic rats. Exercise reduced the gene expression of this protein in diabetic states without reducing the blood glucose. Finally, swimming exercise decreased the malondialdehyde and nitrate levels in heart tissue both in control and diabetic rats.

Conclusion:

Swimming exercise reduces heart expression of the LOX-1 receptor in accompany with reduction of free radicals production. Since these parameters are important in generation of diabetic complications, swimming exercise is a good candidate for reducing these complications. Key Words: Hyperglycemia, Diabetic complications, LOX-1 receptor, Exercise, Free radicals     

大豆水提物对四氯化碳诱导的肝损伤小鼠肝脏抗氧化活力的影响

为研究大豆水提物(SWEs)对四氯化碳(CCl4)所致急性肝损伤小鼠的保护作用以及对肝脏抗氧化活力的影响。将60只试验小鼠随机分为正常对照组、模型组、SWEs低(50 mg·kg-1),中(100 mg·kg-1),高(150 mg·kg-1)剂量组及阳性对照组(联苯双脂,100 mg·kg-1)。每天灌胃给药1次,连续7 d。末次给药1 h后,除正常对照组外的其余5组采用10%CCl42.0 m L·kg-1剂量一次性腹腔注射,建立小鼠急性肝损伤模型。6 h后摘眼球取血及肝脏,计算各组小鼠的肝指数,比色法测定血清谷丙转氨酶(ALT)和谷草转氨酶(AST)活性,及总胆红素(TBIL)和白蛋白(ALB)水平,检测肝组织中丙二醛(MDA)和还原型谷胱甘肽(GSH)水平及一氧化氮合酶(NOS)活性。结果表明:模型组小鼠肝重和肝指数、血清ALT和AST活性及TBIL水平、肝组织MDA水平及NOS活性均显著高于对照组;而血清ALB及肝组织GSH水平显著低于对照组。与模型组相比,中、高剂量的SWEs及联苯双脂显著降低CCl4所致急性肝损伤小鼠的肝重和肝指数、血清ALT和AST活性及TBIL水平、肝组织NOS活性和MDA水平,并显著提高血清ALB及肝组织GSH水平。大豆水提物对CCl4所致小鼠急性肝损伤具有保护作用,其机制可能与抗氧化作用有关。     

Anticancer Activity of a Hexapeptide from Skate (Raja porosa) Cartilage Protein Hydrolysate in HeLa Cells

In this study, the hexapeptide Phe-Ile-Met-Gly-Pro-Tyr (FIMGPY), which has a molecular weight of 726.9 Da, was separated from skate (Raja porosa) cartilage protein hydrolysate using ultrafiltration and chromatographic methods, and its anticancer activity was evaluated in HeLa cells. Methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay indicated that FIMGPY exhibited high, dose-dependent anti-proliferation activities in HeLa cells with an IC₅₀ of 4.81 mg/mL. Acridine orange/ethidium bromide (AO/EB) fluorescence staining and flow cytometry methods confirmed that FIMGPY could inhibit HeLa cell proliferation by inducing apoptosis. Western blot assay revealed that the Bax/Bcl-2 ratio and relative intensity of caspase-3 in HeLa cells treated with 7-mg/mL FIMGPY were 2.63 and 1.83, respectively, significantly higher than those of the blank control (p < 0.01). Thus, FIMGPY could induce apoptosis by upregulating the Bax/Bcl-2 ratio and caspase-3 activation. Using a DNA ladder method further confirmed that the anti-proliferation activity of FIMGPY was attributable to its role in inducing apoptosis. These results suggest that FIMGPY from skate cartilage protein hydrolysate may have applications as functional foods and nutraceuticals for the treatment and prevention of cancer.