石榴籽提取物体外抗氧化活性研究

目的研究石榴籽提取物的体外抗氧化作用。方法采用普鲁士蓝法、邻二氮菲-Fe2+氧化法和邻苯三酚自氧化法分别测定石榴籽提取物的总抗氧化能力、石榴籽提取物对羟自由基(.OH)和超氧阴离子(.O2-)的清除作用,并与维生素C抗氧化活性相比较。结果石榴籽提取物对.OH和.O2-具有很强的清除作用,其IC50分别为0.157和0.027mg/ml,与维生素C抗氧化作用相似。结论石榴籽提取物具有较强的清除自由基能力,是一种天然有效的抗氧化剂。     

石榴皮抗氧化物质提取及其体外抗氧化作用研究

目的: 研究石榴皮提取物体外清除自由基的作用及对低密度脂蛋白(LDL)氧化的影响。方法: 采用 -2O、·OH、ROO·等自由基的生成体系,研究石榴皮提取物清除自由基的活性,并进一步采用LDL体外氧化模型,研究对LDL氧化的抑制作用,并与石榴果汁提取物相比较。结果: 两种提取物均可以有效清除 -2O、稯H、ROO纷杂苫种芁DL氧化,其活性具有剂量效应关系;果皮提取物的各种活性均强于果汁提取物。结论: 石榴皮所含天然抗氧化物质能有效清除 -2O、稯H、ROO返茸杂苫种芁DL氧化,因而可能具有抑制动脉粥样硬化(AS)的作用。     

莲藕提取物体外抗氧化作用研究

目的 研究莲藕提取物的抗氧化活性及其对H2 O2暴露引起的C2 C12细胞氧化应激损伤的保护作用.方法 以莲藕可食部为原料,采用超声波提取法得到莲藕提取物,测定莲藕提取物的总抗氧化力及对DPPH、羟自由基清除作用;选用C2 C12细胞,以H2 O2诱导产生氧化损伤,通过检测细胞活力以及SOD、GSH-Px、CAT的活性...     

十大功劳抗氧化作用研究

目的研究中药十大功劳的体外抗氧化作用。方法采用邻苯三酚自氧化法产生超氧阴离子自由基(O.2-),采用H2O2/Fe2 体系通过Fenton反应产生羟自由基(.OH),用分光光度法分别测定不同浓度的药物对O.2-和.OH的清除作用。结果十大功劳能够抑制邻苯三酚的自氧化速度,并能清除Fenton反应产生的.OH。结论十大功劳具有清除O.-和.OH的能力,这种能力在一定范围内随药物浓度的升高而增强。     

新疆树莓果实营养成分及其提取物抗氧化性研究

目的分析新疆野生树莓果实营养成分,并对其提取物进行抗氧化活性测定。方法进行营养保健成分含量分析,并对果实95%乙醇提取物经石油醚脱脂后,依次用乙酸乙酯、正丁醇萃取,观察不同萃取部位对DPPH·和·OH的清除能力。结果树莓鲜果中必需氨基酸含量高达320mg%,非必需氨基酸中谷氨酸含量较高(180mg%);富含维生素C(28.04mg%)和钾(147.32mg%);有机酸含量高达1.72%,以柠檬酸为主;其它如总酚、总黄酮、鞣化酸、单宁含量分别为498、125、2.2和290mg%,SOD活性高达606.93U/ml。树莓不同提取物均显示了较好的抗氧化活性,以乙酸乙酯部分最高,与清除DPPH自由基相比,清除羟自由基能力强。结论新疆野生红树莓果富含多种营养保健成分和抗氧化活性,有很好的开发价值。     

北京早园竹叶提取物的抗氧化活性研究

目的 初步研究北京早园竹叶提取物的抗氧化能力.方法 采用超声辅助法提取竹叶提取物,NaNO3-Al(NO3)3-NaOH显色法检测总黄酮浓度,并通过二苯基苦基苯肼(DPPH)自由基清除法和CuSO4-Phen-Vc-H2O2-DNA体系化学发光法对其进行抗氧化能力测定.结果 提取物清除DPPH自由基的IC50为7.02 mg/L;竹叶提取物可延迟DNA损伤峰的出峰时间(R<0.01),浓度大于400 mg/L的竹叶提取物可防止DNA氧化损伤.结论 竹叶提取物具有一定的DPPH自由基清除能力,浓度大于400 mg/L的竹叶提取物可显著抑制DNA损伤.     

傣族药材-牙海补乌多糖提取物抗氧化作用

傣族"雅解"药材-牙海补乌[1,2]在植物学分类中为冰糖草(Bingtangcao),别名土干菜、野甘草等,属玄参科,主要分布于云南省西双版纳地区.具有清热解毒,利尿消肿等作用[3].为深入研究该类药材对人体的保健功能,开发其中抗氧化(解除各种毒素,防治各种疾病)的活性成分,本研究选择傣族传统药材一牙海补乌,制备其提取物,进行体外清除羟自由基(·OH)、超氧自由基(O2-)及抑制·OH所致脂质过氧化和对DNA氧化损伤作用的研究.结果报告如下.     

大麦麦叶中黄酮类化合物清除自由基动态研究

目的 :　研究 4种大麦麦叶中提取的黄酮类化合物对超氧阴离子自由基 (O2· )、羟自由基 (· OH)的清除作用。方法 :　用氮蓝四唑 (NBT)光还原法测定 O2·的清除率 ,氧化还原法测定· OH的清除率。结果 :　随着黄酮在反应液中浓度的增加 ,清除率呈上升趋势 ,当黄酮浓度达到 1 2μg/ ml左右时 ,对 O2·和· OH的清除率可分别高达 95.56%和 94.1 2 %。结论 :体外实验证实 ,大麦麦叶提取物具有较强的抗氧化作用     

广枣提取物体外清除活性氧自由基及抗氧化作用研究

利用Fenton反应产生羟自由基.OH,光照核黄素产生超氧阴离子自由基O.-2,分光光度法研究了广枣提取物体外清除活性氧自由基的作用。用硫代巴比妥酸(TBA)分光光度法研究广枣提取物对.OH诱发卵磷脂脂质过氧化损伤的抑制作用。实验结果表明,广枣提取物能有效清除活性氧自由基,对卵磷脂脂质过氧损伤有显著抑制作用。     

薏苡叶乙酸乙酯提取物体外抗活性氧自由基作用研究

目的:测定薏苡叶乙酸乙酯提取液中多酚的含量,以及其提取液体外抗氧化能力的作用,为充分利用薏苡资源提供理论依据。方法:用乙酸乙酯作溶剂,在78℃水浴中超声提取30 min,通过紫外分光光度法测定薏苡中多酚的含量以及提取液清除羟自由基(·OH)、超氧自由基(·O2-)、1,1—二苯基—2—三硝基苯肼(DPPH)自由基能力。结果:薏苡叶提取液中含有较高的多酚,其提取液有较强的清除羟自由基(·OH)、超氧自由基(·O2-)和1,1—二苯基—2—三硝基苯肼(DPPH)自由基的能力。结论:薏苡叶乙酸乙酯提取液有较强的抗氧化能力,其抗氧化性随着提取液浓度的增大而增强。     

Corni fructus scavenges hydroxy radicals and decreases oxidative stress in endothelial cells

Corni fructus has been used as a tonic, analgesic, and diuretic in Korean herbal medicine. The present investigation was undertaken to evaluate the antioxidative effect of corni fructus and its capacity to protect cells against oxidative damage. The radical scavenging activity of corni fructus extracts was measured using 1,1-diphenyl-2-picrylhydrazyl (DPPH), and the antioxidant activity was determined by measuring the peroxide value in a linoleic acid emulsion system. In addition, human umbilical vein endothelial cells (HUVECs) were treated with corni fructus extracts and incubated with H(2)O(2) to investigate protection against apoptosis induction. Both ethanol and water extracts of corni fructus produced higher DPPH radical scavenging activity than hexane, chloroform, and ethyl acetate extracts. Strong antioxidative activities of both water and ethanol extracts were observed in an emulsion system containing linoleic acid and phosphate buffer. The incubation of HUVECs with the addition of ethanol extract significantly decreased H(2)O(2)-initiated damage of endothelial cells, but the water extract did not. The pretreatment with ethanol extract, but not with water extract, significantly decreased apoptotic damage of the H(2)O(2)-treated HUVECs and kept the morphological normality. This study demonstrates that corni fructus is a potent antioxidant substance, and suggests that further investigation is needed to characterize the difference between extract types and to identify its antioxidant compounds.     

珠子参有效止血部位探究及其对内源途径凝血因子的作用

[目的]研究珠子参的止血有效部位及其对内源性途径凝血因子的作用。[方法]分别将珠子参正丁醇、水和乙酸乙酯提取物与抗凝兔血混合,测定其凝血时间。在此基础上用凝血功能的检验方法对各项指标进行测定。[结果]水提取物组与正丁醇提取物组和乙酸乙酯组比较,凝血时间最短,且差异有统计学意义（P﹤0.01）,且凝血时间随浓度增高而逐渐缩短,具有较好相关性。TT、FIB、PT组与空白组间差异无统计学意义（P﹥0.05）。APTT组第2组^第8组APTT为（18.3±0.6）^15.1±0.5s,显著短于空白组凝血时间（26.4±1.3）s（P﹤0.05）,其中以第8组的珠子参提取物浓度为5%的试管的平均凝血时间最短。[结论]珠子参水提取物具有较强的促凝血作用,其机理可能与增强内源途径凝血因子的活性有关,具有较大的开发利用价值。     

对海参糖胺聚糖抗氧化性的研究

目的研究海参糖胺聚糖的抗氧化性。方法以K3[Fe（CN）6]为模型,测定海参糖胺聚糖的还原能力。利用邻苯三酚自氧化产生超氧阴离子自由基（·O^2-）且在320nm处有最大吸收,测定海参糖胺聚糖对羟自由基（·OH^-）和超氧阴离子自由基（·O^2-）的清除能力。结果海参糖胺聚糖有较强的还原力,对羟自由基和超氧阴离子自由基的清除能力与浓度成量效关系,有良好的清除羟自由基和超氧阴离子自由基的作用。结论海参糖胺聚糖具有良好的抗氧化作用。     

Antioxidant and antimutagenic activities of Cinnamomum zeylanicum fruit extracts

Recently, a number of studies on the health benefits associated with natural compounds have been demonstrated. Phenolics in fruits, vegetables, herbs and spices possess potent antioxidant, anti-inflammatory, antimutagenic and anticarcinogenic activities. In the present study, the dried fruits of cinnamon were extracted with ethyl acetate, acetone, methanol and water using a Soxhlet extractor. The total phenolics content of the extracts as determined by Folin–Ciocalteu method were found to be the highest in water extract (44.5%) and the lowest in ethyl acetate (14.4%). The antioxidant activity (AA) of the extracts was evaluated through in vitro model systems such as β-carotene-linoleate, and 1,1-diphenyl-2-picryl hydrazyl (DPPH); the antimutagenicity of these extracts was also assayed against the mutagenicity of sodium azide by Ames test using tester strain of Salmonella typhimurium (TA100) at different concentrations. In both the model systems, the AA of the extracts was found in the order of water>methanol>acetone>ethyl acetate. All the extracts decreased sodium azide mutagenicity in S. typhimurium strain (TA100). At 5000 μg/plate all the extracts showed strong antimutagenicity. The antimutagenicity of water extract was followed by acetone, methanol and ethyl acetate. The results of the present study indicate that under-utilized and unconventional part of cinnamon is a good source of antioxidant and antimutagenic phenolics.     

Assessment of cellular responses to oxidative stress using MCF-7 breast cancer cells, black seed (N. Sativa L.) extracts and H2O2

Black seed (N. Sativa L) is an oriental spice of the family Ranunculaceae that has long been rationally used as a natural medicine for treatment of many acute as well as chronic conditions including cardiovascular disease and immunological disorders. It has been used in the treatment of diabetes, hypertension, and dermatological conditions. There have been very few studies on the effects of N. Sativa as a chemoprevention of chronic diseases as well as in cancer prevention and/or therapy. Oxidative stress is a condition that underlies many acute as well as chronic conditions. The combination and role of oxidative stress and antioxidants in vivo is still a matter of conjecture. Our objective for the present study was to expose MCF-7 breast cancer cells in vitro (as a chronic disease example) to aqueous and alcohol extracts and in combination with H[2]O[2] as an oxidative stressor. Measurement of cell survival under various concentrations and mixtures was conducted using standard cell culture techniques, exposure protocols in 96 well plates and Fluorospectrosphotometry. Following cellular growth to 90% confluencey, exposure to water (WE) and ethanol (AE) extracts of N. sativa and H[2]O[2] was performed. Cell survival indices were calculated from percent survival using regression analysis. Results showed that the alcohol extract and its mixtures were able to influence the survival of MCF-7 cells (indices ranged from 357.15- 809.50 mug/ml in descending potency for H[2]O[2]+AE to the mix of 3). In contrast, H[2]O[2] alone reduced effectively the survival of MCF-7 cells and the least effective combinations in descending potency were AE+H[2]O[2], WE+H[2]O[2], AE+WE, and WE+AE+H[2]O[2]. Mixtures other than AE+H[2]O[2] showed possible interactions and loss of potency. In conclusion, N. Sativa alone or in combination with oxidative stress was found to be effective (in vitro) in influencing the survival of MCF-7 breast cancer cells, unveiling promising opportunities in the field of cancer chemoprevention and/or treatment.     

Antioxidant and antimicrobial activity of Cissus quadrangularis L

Extracts of Cissus quadrangularis L. were tested for antioxidant activity by beta-carotene linoleic acid model and also by 1,1-diphenyl-2-picrylhydrazyl model. The ethyl acetate fraction of both fresh and dry stem extracts at a concentration of 100 ppm showed 64.8% antioxidant activity in the beta-carotene linoleic acid system and 61.6% in the 1,1-diphenyl-2-picrylhydrazyl system. This fraction showed the presence of sterols, vitamin C, and tannins as phytoconstituents. The antioxidant activity of methanol extract and aqueous extract were comparatively less significant than that of ethyl acetate extract, and n-hexane extract showed the least activity. The ethyl acetate extract and methanol extract of both fresh and dry stems further exhibited antimicrobial activity against Gram-positive bacteria, including Bacillus subtilis, Bacillus cereus, Staphylococcus aureus, and Streptococcus species. The results of the study have implications in the use of C. quadrangularis as an antibacterial agent and more so as an antioxidant in several applications requiring these properties.     

新疆红树莓果实不同有效部位提取及其抗氧化活性测定

目的测定树莓果实不同提取部位总酚含量并比较不同提取部位抗氧化活性。方法树莓果实95%乙醇提取物经石油醚脱脂后,依次用乙酸乙酯、正丁醇萃取,对得到的各提取部位浸膏,①以没食子酸为标准品进行总酚含量测定,同时用相对标准偏差(RSD)表示稳定性;②采用1,1-二苯-2-苦肼基和羟自由基清除能力实验测定抗氧化活性。结果①Folin-Ciocalteu比色法具有精密度高、稳定性和重现性好等优点;②各提取部位物总酚含量从GAE10.56mg/g到96.76mg/g,其中以乙酸乙酯部位总酚含量最高(GAE96.76mg/g);③抗氧化实验中,树莓不同提取物均显示了较好的抗氧化活性,其中以乙酸乙酯部位抗氧化活性最高。结论树莓是良好的天然抗氧化剂。     

Antioxidant and cyclooxygenase inhibitory activity of sorrel (Hibiscus sabdariffa)

The antioxidant activity of the hexane, ethyl acetate and methanol extracts of three varieties of sorrel (Hibiscus sabdariffa), as well as their potential for reducing blood viscosity, were studied in vitro. The samples screened were two red [(traditional red (TRED) and early bearing red (ERED)] and one white (WHTE) mature Hibiscus varieties. Antioxidant activity was measured by fluorescence spectroscopy using a model liposome system. Cyclooxygenase inhibitory activity was measured using cyclooxygenase (COX-1 and COX-2) enzymes by monitoring the rate of oxygen uptake in prostaglandin synthesis. Antioxidant activity was the highest overall in the red varieties compared to the white. The methanol extract from the three varieties had the highest activity. The methanol and ethyl acetate extracts of the three varieties of sorrel showed higher COX-1 enzyme inhibition than COX-2 and therefore had high potential to decrease blood viscosity. There was no COX-1 or COX-2 inhibition in the hexane extract. These findings support the ethnomedicinal use of H. sabdariffa in Africa and the Caribbean for the treatment of cardiovascular disease and hypertension.     

Antioxidant activity of far-infrared radiated rice hull extracts on reactive oxygen species scavenging and oxidative DNA damage in human lymphocytes

The antioxidant activities of methanolic extracts of far-infrared irradiated rice hull (FRH) and non-irradiated intact rice hull (IRH) were determined. The antioxidant effects against reactive oxygen species (ROS) were evaluated by measuring scavenging activities against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, superoxide, hydrogen peroxide (H2O2), and nitric oxide radical and capacity for chelating metals. Except for H2O2 scavenging activity, FRH showed higher scavenging activity than IRH; for example, the 50% inhibitory concentration (mg/mL) values for DPPH radical scavenging of FRH and IRH were 0.067 and 0.085, respectively, as compared with 0.362 and 0.012 for butylated hydroxytoluene and alpha-tocopherol, respectively. The effect of rice hull extract on DNA damage induced by H2O2 in human lymphocytes was also evaluated by comet assay. The protective effect of rice hull extract increased as its concentration increased from 12.5 to 50 microg/mL, as indicated by DNA strand breakage decreasing from 38% to 22% with FRH and from 49% to 28% with IRH as compared with H2O2-treated positive controls. When human lymphocytes were post-incubated with rice hull extract for 30 minutes after exposure to H2O2, the protective ability of the rice hulls remained unchanged. These results suggest that methanol extracts of rice hulls possess significant ROS scavenging and metal chelating activities and protective effect against oxidative DNA damage.