李果实中多酚含量及其抗氧化能力研究

为分析不同李品种果实中多酚含量及其抗氧化能力,以14个李品种为试材,测定果皮和果肉中的多酚含量,采用超氧自由基(O_2~-)清除法、羟自由基(OH·)清除法、DPPH法、FRAP法和TBARS法测定抗氧化能力,比较多酚含量、抗氧化能力的差异,分析多酚含量与抗氧化能力的相关性,比较抗氧化能力测定方法间的相关性。结果表明:(1)李果实中富含多酚并且品种间存在差异,不同品种果皮中含量为1.40~3.37 mg·g~(-1) FW,果肉中含量为0.50~0.97 mg·g~(-1) FW,果皮中含量远大于果肉中含量;果皮中多酚含量较高的李品种为皇后李、猪肝李,其次为黑宝石李、红玫瑰李;果肉中多酚含量最高的为秋姬李,其次为威克逊李。(2)李果皮、果肉多酚提取物均具有较强的抗氧化能力,果皮提取物综合抗氧化能力较强的为皇后李、黑宝石李和猪肝李,果肉的为红美丽李、红玫瑰李和秋姬李。(3)果皮中多酚含量与清除O_2~-、OH·能力及DPPH、FRAP、TBARS均呈极显著正相关,果肉中多酚含量与抗氧化能力呈显著正相关。(4)对5种方法的相关性分析表明,各方法从不同的角度评价李果多酚抗氧化能力,方法间均具有很好的相关性,DPPH法与FRAP法综合评价最佳,可作为主要选择。     

Effects of Centella asiatica extracts on cell cycle and intracellular free calcium in spleen lymphocytes

AIM: To investigate the effects of Centella asiatica extracts on the cell cycle and intracellular free calcium ( _i) in spleen lymphocytes. METHODS: Centella asiatica was extracted with alcohol and different organic solvents. Sephadex-LH20 gel column chromatography was applied for further purification. To screen the active constituents, the scavenging ability of the fractions generated by elution of chromatography against radicals of OH·, DPPH· and their anti-proliferative effects on spleen lymphocytes were measured. To assess the cell cycle and _i in spleen lymphocytes, flow cytometry was performed. RESULTS: The D fraction eluted from the crude extract of Centella asiatica was obtained, which had strong suppressive effect on lymphocyte proliferation and decreased the _i of the cells in a dose-dependent manner. The cell cycle of the spleen lymphocytes arrested at S and G₂/M stages when treated with the D fraction. CONCLUSION: The effects of Centella asiatica for lowing _i and arresting cell cycle at S and G₂/M stages of spleen lymphocytes are responsible for its anti-proliferative activitiy.     

人心果、星苹果和曼密苹果抗氧化活性比较

 测定了人心果、星苹果和曼密苹果的主要功能活性成分和抗氧化活性。结果表明：3种水果均含有丰富的还原糖、膳食纤维、多酚、抗坏血酸和维生素E。羟基自由基清除法、DPPH法和ABTS法测定表明,3种水果提取液皆有一定的抗氧化活性,对羟基自由基清除率从高到低依次是人心果、曼密苹果和星苹果,对DPPH·和ABTS?+等自由基的清除以人心果最强,星苹果次之,曼密苹果最差。     

Effects of Centella asiatica extracts on apoptosis of mouse spleen lymphocytes

AIM：To isolate the active compounds of Centella asiatica and to investigate their effects on the apoptosis of mouse spleen lymphocytes. METHODS：Cold soak, polar extraction, silica gel column chromatography and Sephadex LH-20 column chromatography were performed to isolate the active compounds from Centella asiatica, which were identified by the assays of scavenging activity on 1,1-diphenyl-2-picrylhydrayl radical (DPPH·) and hydroxyl radical (OH·). Flow cytometry was performed to observe the effects of Centella asiatica extracts on the apoptosis of spleen lymphocytes in mice. RESULTS：Four extracts (B1, B2, B3 and B4) were obtained by the separating procedure. Among them, the extract B4 exerted a potent scavenging effect on both DPPH· and OH·. Quercetin was identified from the extract B4 by HPLC analysis. The mouse spleen lymphocytes with extract B4 treatment showed a significant rise in the level of apoptosis compared with control group. CONCLUSION：Centella asiatica extract B4 induces apoptosis of spleen lymphocytes, and quercetin is the major substance of extract B4.     

两种粤产粉孢牛肝菌抗氧化活性

研究两种产自广东的粉孢牛肝菌(Tylopilus)——类铅紫粉孢牛肝菌(T.plumbeoviolaceoides)和花盖粉孢牛肝菌(GDGM27210)的子实体水提液和75%乙醇提取液的体外抗氧化活性。结果表明,在实验浓度范围内,两种牛肝菌的子实体水提液和75%乙醇提液有不同程度的抑制亚油酸自氧化和清除自由基DPPH.、羟自由基.OH的作用。其中水提液对抑制亚油酸自氧化作用效果较好,最大抑制率分别可达95.74%和92.79%;而75%乙醇提取液对清除DPPH.效果较好,最大清除率分别可达86.68%和94.03%。     

Isolation and purification of active components from Centella asiatica and observation of their immunosuppressive effect

AIM：To isolate and purify the active components from Centella asiatica, and to observe their effect on the proliferation and apoptosis of mouse spleen lymphocytes. METHODS：Semi-preparative high-performance liquid chromatography was performed to further isolate and purify the extracts from Centella asiatica. The effects of the active components on apoptosis and mitochondrial membrane potential of the spleen lymphocytes were assessed by flow cytometry. The structures of the active components were identified by ultraviolet spectrometry, electrospray ionization negative-ion mass spectrometry, ［1H］ nuclear magnetic resonance (NMR) and ［13C］ NMR. RESULTS：The molecular weights of the active components from Centella asiatica, named compound I and compound II, were 302 and 286, respectively. The compound I and compound II from Centella asiatica significantly inhibited the proliferation, promoted the apoptosis and reduced the mitochondrial membrane potential of mouse spleen lymphocytes. Compound I and compound II were identified as quercetin and kaempferol. CONCLUSION：The compound I and compound II from Centella asiatica show antiproliferative and immunosuppressive effects on mouse spleen lymphocytes by promoting apoptosis and reducing mitochondrial membrane potential.     

粗毛纤孔菌不同极性萃取物对α-葡萄糖苷酶的抑制作用及抗氧化活性研究

为探讨粗毛纤孔菌(Inonotus hispidus)子实体对α-葡萄糖苷酶抑制作用及体外抗氧化活性的影响,采用系统溶剂萃取法对粗毛纤孔菌甲醇粗提物进行萃取,得到石油醚、乙酸乙酯、正丁醇极性萃取物.选用福林酚比色法、α-葡萄糖苷酶活性抑制法、1,1-二苯基-2-三硝基苯肼(DPPH)和2,2-联氮-二(3-乙基-苯并噻...     

紫色丝膜菌抗氧化及降低细胞内活性氧作用

贺兰山紫蘑菇是主要分布在内蒙古阿拉善盟和宁夏境内贺兰山地区的野生食用菌。以贺兰山紫蘑菇的主要代表种—紫色丝膜菌(Cortinarius purpurascens)为材料,对其抗氧化活性进行研究。结果表明:紫色丝膜菌甲醇提取物乙酸乙酯相的活性最好,在0.5 mg/mL的浓度下对DPPH和羟基自由基的清除率分别达88.3%和96.8%;紫色丝膜菌甲醇提取物乙酸乙酯相可显著保护自由基诱导的DNA断裂;在0.05 mg/mL时对叔丁基过氧化氢引起的细胞内活性氧水平有极显著降低作用,在0.15mg/mL时可将细胞内升高的活性氧降低到正常水平。     

款冬叶片总黄酮提取工艺优化及抗氧化活性研究

以款冬叶片为试材,采用微波辅助法提取总黄酮,在单因素试验的基础上,采用正交实验法优化款冬叶片总黄酮提取工艺,同时以分光光度法测定提取物对1,1-二苯基-2-三硝基苯肼自由基(1,1-diphenyl-2-picrylhydrazyl,DPPH·)、羟基自由基(·OH)和超氧阴离子自由基(O-·2)的清除作用。结果表明:款冬叶片总黄酮最佳提取条件为乙醇体积分数70%,微波提取时间3 min,微波功率500 W,料液比1∶15 g·mL^-1,在该条件下,总黄酮的提取率为0.91%。款冬叶片总黄酮的质量浓度与抗氧化活性呈一定的线性关系,当总黄酮质量浓度为0.069 8 mg·mL^-1时,对DPPH·、·OH和O-·2的清除率分别达84.21%、84.10%和68.32%,表明款冬叶片具有良好的抗氧化能力,可作为天然的抗氧化剂进一步的开发和利用。     

松杉灵芝提取物体外抗氧化活性的研究

利用1,1-二苯基-2-苦基肼自由基(.DPPH)、脂质过氧化(LPO)和羟基自由基(.OH)3种抗氧化活性分析方法,对松杉灵芝石油醚提取物(PE)、氯仿提取物(TE)、甲醇提取物(ME)、水提取物(WE)进行抗氧化评价。结果表明,在2 mg.mL-1时,各组提取液都具有明显的抗氧化活性,对.DPPH自由基的清除率分别为68.73%(ME)、65.28%(WE)、57.78%(PE)和51.56%(TE);对脂质过氧化的抑制率分别为64.55%(ME)、59.72%(WE)、55.63%(PE)和49.31%(TE);对.OH自由基的清除率分别为100.00%(WE)、81.26%(ME)、75.07%(TE)和60.34%(PE)。提取物浓度与抗氧化性成正相关,甲醇层和水层的抗氧化活性最好。     

蛹虫草白化菌株抗氧化活性

研究蛹虫草白化菌株AB6的子实体水提液和50%乙醇提取液的体外抗氧化活性,结果表明,AB6子实体水提液和50%醇提液对有机自由基DPPH.的清除作用及对亚油酸自氧化的抑制作用都强于出发菌株B6。AB6的水提液对羟自由基.OH具有很强的清除能力,但其醇提液的清除作用低于B6。     

猴头菇子实体对运动后细胞氧化损伤的保护作用

对猴头菇多糖样品进行了O2^-、DPPH·、·OH的清除试验,试验结果显示,猴头菇子实体具有良好的清除多种自由基的能力,体外抗氧化性试验证明了猴头菇子实体具有良好的抗氧化活性,能够增强细胞的抗疲劳和抗衰老能力,对运动细胞氧化损伤具有一定的保护作用。     

苹果多酚提取物抗氧化活性的体外试验

从还原能力、抗脂质过氧化和对不同体系产生的活性氧自由基清除效果等方面对苹果多酚提取物的抗氧化 活性进行了试验研究和评价。结果表明苹果多酚提取物具有较强的还原能力,对脂质过氧化、Fenton反应产生的羟 自由基和光照核黄素及邻苯三酚自氧化产生的超氧阴离子自由基均具有很强的抑制作用或清除作用,且在试验浓 度范围内其最大抑制率或清除率分别可达到94.4％、96.64％、95.19％和90.48％,优于同浓度维生素C的效果或基本 相当。这表明该苹果多酚提取物是一种优良的天然抗氧化剂和自由基清除剂。     

鸡腿菇多糖减轻运动疲劳的机理分析

对鸡腿菇多糖的抗氧化活性进行了试验,试验表明,鸡腿菇多糖对·OH和DPPH·都具有一定的清除活性,且清除率与多糖的浓度成正比。这说明鸡腿菇多糖能够防止人体细胞膜过氧化损伤,减轻运动员的疲劳。     

响应面法优化超声波循环提取长裙竹荪抗氧化物质工艺研究

利用Box-Benhnken中心组合实验和响应面分析法,在前期单因素试验基础上,以提取温度、超声功率和工作间歇比为自变量,以粗提物对DPPH.清除率为响应值,对超声波循环提取长裙竹荪(Dictyophoraindusiata)抗氧化物质工艺进行优化。优化后确定的最佳提取工艺条件为:提取温度45℃,超声功率580 W,工作间歇比3.6/1,在该条件下,粗提物对DPPH.自由基清除率达到46.45%,粗提物得率为30.37%。     

几种香蕉废弃物清除DPPH自由基的作用

测定了几种香蕉废弃物不同溶剂提取物及不同生长期香蕉果实(果皮及果肉)的DPPH自由基清除作用;此外,还对不同材料、不同蕉类品种废弃物的DPPH自由基清除效果进行了比较,以期研究香蕉废弃物的抗氧化活性。结果表明:大部分材料的80%甲醇、80%乙醇、80%丙酮提取物均具有很强的DPPH自由基清除作用,其中80%丙酮提取物的自由基清除作用稍强;所有材料中,嫩苞片及花显示了很强的DPPH自由基清除能力,其IC50值分别为0.6834和0.6853mg/mL,不同材料的80%乙醇提取物的DPPH自由基清除作用强弱顺序依次为:嫩苞片花青色果皮(未成熟)黄色果皮(成熟)老苞片果轴;在整个生长期间,香蕉果皮的自由基清除作用由强变弱,而果肉则与之相反;不同蕉类品种的各种废弃物自由基清除作用强弱顺序依次为:香蕉(威廉斯B6,Williams B6)红蕉大蕉粉蕉。     

Antioxidant and serum lipid lowering effects of luffa cylindrical on experimental hyperlipidemia mice

AIM: To observe the antioxidation and the serum lipid lowing effects of polyphenols in luffa cylindrical on experimental hyperlipidemia mice. METHODS: Acetone was used to extract polyphenols from luffa cylindrical. The content of polyphenols was determined by Folin-ciocalteau method. The inhibitory efficacy of the extracts from luffa cylindrical to the production of OH· free radical was measured. Kunming mice were used to establish the hyperlipidemia model by feeding high fat diet. The freeze-dried fresh luffa cylindricals was added to the treated animals, xuezikang was also used as a positive control. After feeding high-fat food for 14 days, serum were collected to measure the total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C) and superoxidedismutase (SOD). The liver tissue was also collected for determining malonaldehyde (MDA) content. RESULTS: (1) Content of polyphenols in fresh luffa cylindrical was （0.3±0.1）g /kg. (2) The polyphenol extracts from fresh luffa cylindrical had a strong efficacy to inhibit the production of OH· free radicals. (3) The trend of body weight gain in groups LC1 (low dosage luffa cylindrical) and LC2 (high dosage luffa cylindrical) became slow down obviously, compared with that in group HPL (high-lipid model). (4) The levels of TC (4.19±0.37)mmol/L and LDL-C (2.77±0.79)mmol/L in group LC1, TC (3.56±0.55)mmol/L and LDL-C (2.34±0.41)mmol/L in group LC2, TC (4.59±0.96)mmol/L and LDL-C (3.25±0.67)mmol/L in group PC (positive control) were all lower than those in group HPL(P<0.01), which the decrease in the levels of TC and LDL-C in group LC2 was the most obvious. (5) SOD levels in the serum of mice in groups LC1 and LC2 were (337.00±29.73)U/mL and (349.00±9.99)U/mL respectively, which were higher than those in groups HPL and blank control, therein the SOD level in group LC2 increased obviously(P<0.01) compared with group HPL. The MDA levels in liver tissue in group LC2 was lower than those in control. CONCLUSION: Polyphenols in the luffa cylindrical are comparatively strong antioxidant. They effectively decrease the liver index and serum lipid in experimental mice.     

苹果加工品种多酚提取物的抗氧化效果分析

研究加工苹果品种的多酚组成及其抗氧化功能,有助于加工原料的选择和功能性食品的开发。测定了4个酿酒品种和4个制汁品种果实的多酚组成,果实多酚提取物清除超氧阴离子自由基、羟基自由基能力和抗脂质过氧化能力。结果表明,供试加工品种总酚含量为644.9￣3511.8mg/kg,原花青素、绿原酸、表儿茶素、儿茶素是果实中的主要多酚物质。各品种多酚提取物都有一定的抗氧化能力,以稀释10倍的浓度清除3种自由基的能力较强。原花青素、儿茶素与加工苹果果实抗氧化能力有较密切的关系。     

分蘖洋葱鳞茎总黄酮提取工艺及抗氧化活性

以分蘖洋葱‘M-3’鳞茎为试材,用超声波辅助提取黄酮类化合物,在单因素试验基础上,采用Box-Behnken响应面法优化分蘖洋葱总黄酮提取工艺,用DPPH法对总黄酮化合物抗氧化活性进行评价。结果表明:最佳提取工艺参数为料液比1∶45 g·mL^-1、乙醇体积分数60%、提取时间40 min、提取温度48℃、超声波功率310 W。在该条件下,分蘖洋葱总黄酮的提取率为3.584%,与模型预测值3.622%相近。分蘖洋葱总黄酮提取物对DPPH·具有一定的清除作用,IC50值为0.179 mg·mL^-1。优选的超声波提取工艺提高了分蘖洋葱总黄酮提取率,具有较强的抗氧化活性。     

云南杨梅中多酚类物质的提取与活性研究

以云南富民杨梅为原料,提取其中的多酚类活性物质进行总酚含量测定,并进一步研究其抗氧化、抑制亚硝胺能力。试验结果表明:杨梅总酚含量140.43mg/100g样品。DPPH自由基法显示,杨梅多酚提取物具有一定的清除DPPH自由基能力,其清除能力与多酚提取物浓度之间存在明显的剂量效应关系,随着杨梅多酚提取物浓度的增大,其清除二苯代苦味酰自由基(DPPH)的能力增强。在与2,6-二叔丁基对甲酚(BHT)的抗氧化性比较中,杨梅多酚提取物的抗氧化性明显要高于合成的抗氧化剂BHT,当杨梅多酚提取物的浓度0.20mg/ml时,清除羟自由基的清除率为91.60%,同等条件下,杨梅多酚提取物清除羟自由基的清除率是常用抗氧化剂BHT的1.52倍。杨梅中多酚类物质具有良好的阻断亚硝胺合成能力,有一定的清除亚硝胺能力,当杨梅多酚提取物含量为0.60mg/ml时,清除率最高。