Antihypertensive and antioxidant effects of the Graptopetalum paraguayense E. Walther extract in spontaneously hypertensive rats

BACKGROUND: Our previous in vitro study showed that 50% ethanolic extract of Graptopetalum paraguayense E. Walther (GE50) exhibited an inhibitory effect on angiotensin I converting enzyme (ACE). This study was aimed at evaluating the antihypertensive and antioxidant effects of GE50 extract on spontaneously hypertensive rats (SHR). RESULTS: Daily oral administration of GE50 extract (2.5 g kg⁻¹ body weight) for 4 weeks exhibited a significant decrease in blood pressure as well as ACE activity of tested tissues in SHR rats, while no significant change was found in normotensive Wistar Kyoto rats (WKY). For SHR, GE50 extract increased the total antioxidant status in the plasma and decreased malondialdehyde levels in all tested tissues. Furthermore, GE50 extract increased α‐tocopherol and glutathione levels in brain tissue, glutathione peroxidase and catalase activities in heart, as well as catalase activity in liver tissue. In WKY rats, GE50 extract only increased ascorbic acid level in liver tissue. CONCLUSION: The present study demonstrated that GE50 might serve as an antioxidant and an ACE inhibitor in convalescence from hypertension in rats. Copyright © 2009 Society of Chemical Industry     

Effects of Graptopetalumparaguayense extract on tert‐ butylhydroperoxide‐induced oxidative stress

BACKGROUND: Graptopetalum paraguayense E. Walther is used in folk medicine to lower blood pressure, protect liver function and relieve pain and infection. The effect and mechanism of its 50% ethanolic extract (GE50) were investigated in tert‐butylhydroperoxide (t‐BHP)‐induced Wistar rats. The serum was analysed for aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities while the tissue cytosols were analysed for lipid peroxidation, antioxidant level and enzyme activities. RESULTS: The liver was the primary target organ while the heart appeared to be the least responsive organ for t‐BHP treatment among the three tissues investigated. t‐BHP treatment increased serum AST and ALT activities, which are indicators of liver toxicity, while GE50 pretreatment reduced t‐BHP‐induced liver damage. t‐BHP treatment induced lipid peroxidation in the liver and brain but not in the heart. GE50 pretreatment prevented t‐BHP‐induced lipid peroxidation by maintaining superoxide dismutase (SOD) activity as well as glutathione (GSH) and vitamin C levels in the liver and vitamin E level in the brain. Although t‐BHP treatment did not induce lipid peroxidation in the heart, it caused a decrease in antioxidant level. GE50 pretreatment prevented the t‐BHP‐induced decrease in vitamin C level in the heart. CONCLUSION: GE50 pretreatment in rats protects the liver and brain from possible damage by t‐BHP‐induced lipid peroxidation. Copyright © 2007 Society of Chemical Industry     

Studies on the inhibitory effect of Graptopetalum paraguayense E. Walther extracts on the angiotensin converting enzyme

This study was aimed at evaluating the kinetic properties and capacities of water (GWE), 50% ethanolic (GE50) and 95% ethanolic (GE95) extracts from Graptopetalum paraguayense for the potential to inhibit angiotensin converting enzyme (ACE). The results showed that GWE, GE50 and GE95 showed potent inhibitory effects on ACE. It was found that the ACE inhibitory activities of all the tested extracts increased with the increase of their concentrations. In addition, the ACE inhibition of the tested extracts of G. paraguayense were significantly reduced after the addition of 1.5 mM ZnCl₂, suggesting the inhibitory action of the extracts may have resulted from the chelation of the ACE zinc cofactor. The inhibition kinetics, analyzed by Lineweaver–Burk plots, revealed that G. paraguayense extracts showed a mixed-type inhibition. A comparison of the 50% inhibition concentration (IC₅₀) and K_i values showed that the ethanolic extracts, including GE50 and GE95 exhibited the more effective ACE inhibitory activity than the water extracts of G. paraguayense.     

抗氧化剂维生素E及其代谢物的毒理损伤

从维生素E及其在抗氧化历程中产生的代谢物的分子结构与功能入手,综述了新近发现的维生素E及其代谢物的毒理损伤,包括与心肌梗塞、高血压及肝硬化等疾病的产生关系密切.因此,在使用抗氧化剂时,应注意:①重新建立一套安全评估方案;②从分子水平更详尽地了解抗氧化剂的动力学变化和分子转化,以此对其利弊作出正确评估;③从生物动力学与生物效果模型中找出最佳食用剂量.     

抗氧化剂处理对微冻贮藏泥鳅品质及脂肪氧化的影响

研究丁香提取物、油菜粉提取物、植酸、VE及2,6-二叔丁基对甲苯酚(BHT)处理对微冻(-2.5℃)贮藏泥鳅品质及脂肪氧化的影响。结果显示,不同处理组泥鳅的感官综合得分逐渐降低;pH值先下降后上升;汁液流失率呈增加趋势;剪切力不断降低(P0.05);挥发性盐基氮(TVB-N)值呈增加趋势,且所有处理组在24d时均小于最大限量(20mg/100g),处于可接受范围;硫代巴比妥酸值(TBARS)、过氧化值(POV)均呈上升趋势(P0.05);饱和脂肪酸(SFA)、单不饱和脂肪酸(MUFA)含量整体升高,多不饱和脂肪酸(PUFA)含量相对下降。以上所有处理组的变化趋势均优于对照组。综合上述分析,对照组在微冻条件下的货架期为8～12d,而添加抗氧化剂组货架期均达到20～24d,其中植酸、BHT以及VE抗氧化能力更强,能够更有效地抑制不饱和脂肪酸氧化,维持样品的食用品质和加工性能。     

Effects of different polarity of onion skin extracts on antioxidative properties and non-volatile profiles

Onion skins are agricultural by-products that contain high levels of antioxidants, including quercetin and protocatechuic acid. The solubility of extracts can affect their antioxidant capacity in food oil matrices. The antioxidative properties of onion skin extracts with different polarity were compared and the chemical profiles of the extracts were identified by GC-MS. Highly lipophilic, moderately hydrophilic and highly hydrophilic onion skin extracts (HLE, MHE and HHE, respectively) were prepared and their antioxidant properties were tested using in vitro assays and bulk oil or oil-in-water (O/W) emulsions. The most abundant phenolic compounds in the onion skin extracts were quercetin and protocatechuic acid. The lipophilicity levels of HLE, MHE and HHE were 0.674, 0.394 and −1.225, respectively. HLE showed higher antioxidant capacity in bulk oil and O/W emulsion matrices compared to MHE and HHE. The antioxidant capacity of HLE was higher in the O/W emulsion than in the bulk oil system. Therefore, highly lipophilic onion skin extracts can be used as effective natural antioxidants in oil matrices, especially O/W emulsions.     

Antrodia camphorata ameliorates high-fat-diet induced hepatic steatosis via improving lipid metabolism and antioxidative status

Nonalcoholic fatty liver disease (NAFLD) commonly results from excessive dietary fat intake which characterized by obesity and insulin resistance. Wild fruiting body of Antrodia camphorata (AC) was assayed for alleviative effects on NAFLD. An NAFLD animal model was successfully established in male 7-week-old C57BL/6 mice fed with high-fat diet (HFD) for 36 weeks. The HFD mice exhibited obese and impaired glucose metabolism. After an induction of NAFLD syndrome, AC was given for one week via gavage. Mice with AC treatment showed lowered (p < 0.05) serum TG and TC, lowered (p < 0.05) liver TG content, improved (p < 0.05) oxidative status (TBARS values and GSH levels), and ameliorated (p < 0.05) liver damage (AST, ALT, and LDH values). In addition, AC activated (p < 0.05) gene expressions of PPAR-α with its downstream genes in the liver and caused higher (p < 0.05) rectal temperature, which showed AC attenuates hepatic lipid accumulation by promoting lipid oxidation and further suggests the role of AC in energy expenditure. Overall, our findings revealed that AC possesses alleviative effect on NAFLD.     

Antioxidant properties of Lactobacillus-fermented and non-fermented Graptopetalum paraguayense E. Walther at different stages of maturity

Accumulation of bioactive compounds, during developmental stages of Graptopetalum paraguayense E. Walther, was investigated between 30 and 90 days as a function of physiological maturity. Three distinct phases were defined: immature phase (30 days), intermediate developmental phase (30–60 days), and maturation phase (60–90 days). Gallic acid and quercetin, antioxidative bioactive compounds, were identified as biomarkers for determining the optimum physiological maturity stage in G. paraguayense E. Walther. With regard to the antioxidant activity of G. paraguayense E. Walther at different developmental stages, the results indicated that the leaves of immature G. paraguayense E. Walther had the highest 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonate) (ABTS-), superoxide radical-, and 1,1-diphenyl-2-picrylhydrazyl (DPPH·)-scavenging activities. Fermentation of G. paraguayense E. Walther with Lactobacillus plantarum BCRC 10357 significantly increased the level of flavonoids and total phenolics, including quercetin and gallic acid. Total phenols were the major naturally occurring antioxidant components in lactic acid bacteria-fermented G. paraguayense E. Walther.     

The antioxidative properties of Holy basil and Galangal in cooked ground pork

The ethanolic extracts from Holy basil and Galangal were examined for their extraction yield, total phenolic content, antioxidant activity against a β-carotene-linoleic acid emulsion system, DPPH scavenging activity and reducing power. Ethanolic extracts of Holy basil exhibited higher extraction yield, total phenolic content, antioxidant activity, DPPH scavenging activity and reducing power than ethanolic extracts of Galangal. Antioxidative efficiency to inhibit lipid oxidation of dried Holy basil and dried Galangal powder, ethanolic extracts of Galangal and Holy basil and commercial antioxidant mixture in cooked ground pork was investigated during refrigerated storage at 5°C for 14 days. The quantitative measurements of thiobarbituric acid reactive substances (TBARS), conjugated diene, peroxide value (POV) and hexanal content were used as indicators of lipid oxidation. Increased levels of TBARS value, POV and hexanal content were noticed in all meat samples during storage, however most marked in cooked ground pork without antioxidants, whereas conjugated diene tended to decrease with increasing storage time. Ranking of the treatment in order of their antioxidant effectiveness showed that commercial antioxidant mixture (0.3% citric acid+0.5% ascorbic acid+0.02% α-tocopherol)>dried Galangal powder>dried Holy basil powder>ethanolic extracts of Galangal>ethanolic extracts of Holy basil>control. Furthermore, in cooked ground pork samples a high correlation between TBARS value and hexanal contents was obtained.     

Effect of natural antioxidant combinations on lipid oxidation in cooked chicken meat during refrigerated storage

The effect of combinations of sage, oregano and honey on lipid oxidation in cooked chicken meat during refrigeration at 4°C for 96h was determined. Chicken samples (thigh and breast) were then separated into five groups: control; butylated hydroxytoluene; oregano+sage; oregano+sage+5%honey and oregano+sage+10%honey. Quantitative measurements of thiobarbituric acid reactive substances, conjugated dienes, hexanal, fatty acids, cholesterol and cholesterol oxides were used as indicators of lipid oxidation. Acceptability and preference were also evaluated. The effectiveness of the natural antioxidants for reducing the velocity of lipid oxidation in cooked chicken thigh and breast was demonstrated after 48 and 96h of refrigeration at 4°C. The treatments that presented the lowest hexanal values after 96h of refrigeration were oregano+sage+5%honey and oregano+sage+10%honey. Only traces of free cholesterol oxides were found (25-OH, 7-k, 7α-OH and 7β-OH). The natural antioxidants protected cooked chicken meat from oxidation processes and resulted in great acceptability.     

Effects of persimmon-vinegar on lipid and carnitine profiles in mice

The aim of this study was to investigate the effects of persimmon-vinegar supplementation on blood lipid profiles, carnitine concentrations, and hepatic mRNA levels of enzymes involved in fatty acid metabolism. Thirty-two C57BL/6J male mice were divided into 4 groups; control group (HD), industrial vinegar group (HD-V), and persimmon-vinegar groups (HD-PV1, HD-PV2). Serum triglyceride (TG) and total cholesterol (TC) concentrations significantly decreased in all vinegar-administered groups compared with the HD group. The hepatic TG and TC concentrations of persimmon-vinegar administered groups were significantly lower compared with the HD group. Liver acid insoluble acylcarnitine (AIAC) was significantly higher in the HD-PV2 than in HD and HD-V groups. The acetyl-CoA carboxylase (ACC) mRNA level tended to lower in all the vinegar administered groups compared with the HD group. These results suggest that the persimmon-vinegar has anti-obesity properties.     

不同温度下高压处理牛肉TBARS值的变化及抗氧化剂和螯合剂的抑制作用研究

对不同温度(20℃、40℃和60℃)下压力(从200～800MPa)处理20min以及在4℃下贮藏7d后牛肉脂肪TBARS值的变化进行了研究。结果显示:常压下肌肉的TBARS值随热处理温度的升高而增加;同样,室温下压力的增加导致脂肪氧化程度的加剧,尤其是在400MPa及其以上压力;40℃和60℃下的压力处理,TBARS值的变化规律与室温下极为相似。添加1%的Na2EDTA可有效地降低肌肉不同温度(20～60℃)下200MPa和600MPa压力处理和贮藏后的TBARS值,阻止压力和热处理导致的脂肪氧化,此结果表明热和压力处理的肌肉中蛋白质结构的破坏和过渡金属离子的释放是造成脂肪氧化的主要原因。VE和BHT也具有良好的抗氧化作用,0.05%的VE和0.02%BHT结合使用,比单独的VE具有更好的抗氧化效果。     

茶多酚和TBHQ对猪肉脯贮藏过程中色泽的影响

为防止脂质氧化,常在猪肉脯中添加抗氧化剂,但对于添加抗氧化剂对猪肉脯色泽的影响研究鲜有报道。通过在猪肉脯中分别添加0.02%的天然抗氧化剂茶多酚和0.02%的化学抗氧化剂TBHQ(特丁基对苯二酚),在其他实验条件相同的情况下,研究猪肉脯贮藏过程中两种抗氧化剂对色泽的影响。结果表明,在猪肉脯中添加两种抗氧化剂,CIEL*、CIEa*、CIEb*值均呈显著性下降趋势(p<0.05);POV(过氧化值)总体先增加后下降并且添加组小于对照组,且添加组的POV与各自的CIEL*、CIEa*、CIEb*均呈极显著相关性(p<0.01);pH整体变化趋势基本一致,都是先增加而后下降,且各组pH与其CIEL*、CIEa*、POV之间均呈现显著相关性(p<0.05)。结果表明,抗氧化剂对猪肉脯贮藏过程中色泽变化具有显著性影响。     

Effect of lipid oxidation and frozen storage on muscle proteins of Atlantic mackerel (Scomber scombrus)

The effect of storage on the lipids and proteins in Atlantic mackerel stored for up to 24 months at ?20 and ?30 °C was studied. Traditional methods including the peroxide value, thiobarbituric acid‐reactive substances (TBARS) and a reverse phase HPLC method were used to determine the primary and secondary lipid oxidation products. All tests showed an increase in lipid oxidation products with storage time and at a higher storage temperature of ?20 °C compared with samples stored at ?30 °C. Antioxidants had a significant effect (P < 0.01) on the inhibition of lipid oxidation, as shown by the reduction in peroxide value and hydroxides, and malondialdehyde formation. Similarly, deterioration of protein structure and functionality in mackerel stored for 3, 6, 12 and 24 months was greater at ?20 than ?30 °C. ATPase activity in the myosin extract of Atlantic mackerel showed a significant decrease (P < 0.01) with progressive frozen storage. Protein solubility in high salt concentration (0.6 M NaCl) decreased (P < 0.01) during storage at both ?20 and ?30 °C but was greater at ?20 °C. Interestingly, antioxidants BHT, vitamin C and vitamin E protected the proteins against complete loss of ATPase activity and protein solubility to a significant level (P < 0.01) for up to 1 year at ?20 °C compared with samples stored without antioxidants. This study confirms the deleterious effect of lipid oxidation products on protein structure and function in frozen fatty fish. © 2002 Society of Chemical Industry     

脉冲强光及抗氧化剂对动物油脂的影响

研究了不同抗氧化剂对动物油脂的抗氧化作用,探讨了脉冲时间、贮藏温度以及抗氧化剂对经脉冲强光处理动物油脂氧化的影响。结果表明,VE、燕麦油、VC和杨梅多酚4种物质对动物油脂都有抗氧化作用,其添加的最佳质量分数分别为0.5%、0.5%、0.01%0、.07%。脉冲强光处理可加速动物油脂的过氧化,且随脉冲强光闪照时间的增加,动物油脂的氧化程度加剧。经脉冲强光处理的动物油脂其在不同温度下的贮藏稳定性均有所下降;随贮藏温度的升高和脉冲闪照时间的增加,油脂的氧化速度加快。脉冲强光处理前添加的VE、燕麦油和杨梅多酚仍具有降低脉冲强光诱导动物油脂的过氧化作用,而VC却产生促氧化作用。     

Inhibitory Effects of Red Wine on Lipid Oxidation in Fish Oil Emulsion and Angiogenesis in Zebrafish Embryo

The capabilities of red wine against lipid oxidation and angiogenesis were evaluated by using a fish oil emulsion system and an in vivo zebrafish embryos model, respectively. The red wine contained 12 different antioxidant phenolics which levels were led by anthocyanins (140.46 mg/L), catechin (55.08 mg/L), and gallic acid (46.76 mg/L). The diversity of the phenolics in red wine was greater than the tea, coffee, or white wine selected as a peer control in this study. The total phenolics concentration of red wine was 305.53 mg/L, although the levels of tea, coffee, and white wine were 85.59, 76.85, and 26.57 mg/L, respectively. The activity of red wine in scavenging DPPH (2,2‐diphenyl‐1‐picrylhydrazyl) free radicals was approximately 4 times higher than the tea and 8 times than the coffee or white wine. The red wine showed the highest capability in preventing long chain PUFA oxidation in the fish oil emulsion. Because of the outstanding antioxidant activity of red wine, the red wine dried extract was used to monitor its inhibitory effect against angiogenesis by using transgenic zebrafish embryos (Tg[fli1:egfp]^y1) with fluorescent blood vessels. After incubated in 100 μg/mL of the extract solution for 26 h pf, each of the embryos had a lower number of intersegmental vessel than the control embryo. The inhibition rate of red wine extract against growing of angiogenic blood vessel reached 100%.     

不同抗氧化剂体外抗氧化活性及其对肉品氧化稳定性的影响

为明确GB 2760-2014《食品安全国家标准食品添加剂使用标准》中允许添加至热加工肉制品使用的不同抗氧化剂的体外抗氧化活性与其抑制肉制品蛋白质氧化和脂肪氧化能力之间的关系,分别测定8种抗氧化剂的体外抗氧化活性(1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由...     

Metabolic impact of 100% fruit juice consumption on antioxidant/oxidant status and lipid profiles of adults: An Evidence-Based review

One hundred percent fruit juice (FJ) contains bioactive compounds with antioxidant activity. As such, this fruit form has the potential to improve antioxidant status and mediate outcomes influenced by redox status. A systematic review of the literature published between 1995 and 2013 was conducted using PubMed database to evaluate associations between intake of 100% FJ and markers of antioxidant/oxidant status and blood lipid levels in healthy, free-living adults ≥18 years. Data extraction and analysis was conducted according to the Academy of Nutrition and Dietetics Evidence Analysis Process. Limited evidence from ten clinical trials meeting inclusion/exclusion criteria suggests potential improvements in a variety of antioxidant or oxidants biomarkers postconsumption of 100% FJ. Weak evidence from five studies suggests that one or more blood lipid measures may be positively influenced by consumption of 100% FJ. Heterogeneity in study methodology including biomarkers, 100% FJ type, dosage, and intervention duration precludes the ability to make evidence-based recommendations regarding a specific dose-duration-juice effect. Key characteristics in study designs were identified which must either be controlled or statistically adjusted for in future investigations in order to obtain a more accurate understanding of the complex relationship between metabolic outcomes and consumption of 100% FJ in context of a healthy dietary pattern.