山竹果皮浸泡酒的活性成分及抗氧化活性变化

以山竹果皮为原料制备浸泡酒,研究果皮浸泡过程中多酚、黄酮、花色苷等活性物质含量及色度的动态变化,并以DPPH自由 基清除能力和铁离子还原能力（FRAP）为评价指标,探讨山竹果皮浸泡酒浸泡期间抗氧化活性变化。 结果表明,果皮浸泡过程中活性 成分溶出量均随浸泡时间的延长而增加,且烘干样品效果较好。 其中花色苷含量在浸泡3 d时较高,为1.76 mg/L;黄酮、多酚含量在浸 泡7 d时较高,含量分别为2.43 mg/mL、480.82 μg/mL;浸泡5 d时酒色度达到最高,为0.34。 抗氧化活性实验结果表明,在浸泡过程中, DPPH自由基清除率在第3天达到稳定,为77.77%,而还原能力在第7天达到稳定,为6.422×10-4 mmol。 因此,烘干的山竹果皮用白酒浸 泡7 d后,得到的酒液中主要活性成分含量较高,抗氧化作用较好。     

红毛丹果皮抗氧化物质的提取及其抗氧化作用

考察了不同浓度的甲醇溶液对红毛丹果皮中多酚和黄酮物质的超声提取作用,并研究了不同甲醇提取液的还原能力、DPPH·和羟自由基清除能力。结果表明,60%和90%的甲醇溶液对红毛丹果皮多酚的提取率较高,90%的甲醇溶液对黄酮的提取率最高。30%、60%、90%甲醇和水溶液对DPPH·自由基清除能力的IC50值均在4μg/mL左右;对羟自由基清除能力的IC50值分别为46.80、34.06、36.69、80.30μg/mL。结果表明:不同甲醇提取液均具有较强的还原能力、DPPH·和羟自由基清除能力,其IC50值均为μg/mL级。一定浓度范围内,提取液抗氧化能力与其多酚的含量呈正相关性。90%和60%的甲醇提取液的抗氧化能力明显高于30%甲醇和水提取液。综合考虑对多酚的提取率、抗氧化能力以及提取成本等因素,可采用60%的甲醇作为提取液。      

胡杨花序乙醇提取物体内抗氧化活性研究

探讨胡杨花序乙醇提取物的体内抗氧化活性,分别用165 mg/kg BW、330 mg/kg BW、660 mg/kg BW剂量组的胡杨花序提取物和生理盐水对照组给试验小鼠每日灌胃,检测小鼠血清和肝匀浆中的超氧化物歧化酶（SOD）的活性及丙二醛（MDA）的含量。与对照组相比,花序提取物灌胃各组小鼠血清和肝组织中的SOD活力显著提高（P〈0.05）,同时MDA的含量显著降低（P〈0.05）。结果表明,胡杨花序可以提高小鼠机体的抗氧化能力,抑制脂质过氧化物。     

柑桔皮提取液的抗氧化作用研究

采用微波强化浸提法提取桔皮中的活性物质,测定提取液对羟自由基、超氧阴离子和过氧化氢的清除效果.实验结果表明：桔皮提取液对活性氧具有很高的清除作用,0.5 mL桔皮提取液对羟自由基的清除率达到100%,对超氧阴离子的清除率达到98%以上,稀释100倍的桔皮提取液0.7 mL对过氧化氢的清除率仍可达25%左右.在保藏猪油的抗氧化应用实验中,0.5%添加量的桔皮提取液的抗氧化效果与相同添加量的Vc的抗氧化效果相当.     

菠萝蜜果皮不同萃取部位抗氧化活性的研究

为了深入研究菠萝蜜果皮石油醚、乙酸乙酯、水三个萃取部位的抗氧化活性,通过DPPH、ABTS、FRAP三种方法对其抗氧化活性进行评价,并考察了各个部位中多酚、黄酮含量。结果表明,菠萝蜜果皮乙酸乙酯部多酚和黄酮的含量最高,分别为1.346、1.102mg/g,而水部含量最低,分别为0.593、0.029mg/g。不同部位中抗氧化活性大小顺序为乙酸乙酯部（EA）>石油醚部（PE）>水部（W）,其中乙酸乙酯部对DPPH自由基抑制率最高可达到94%,对ABTS+自由基抑制率可达99.1%,总抗氧化能力FRAP值可达952.6μmol/L。      

洋葱皮提取物对营养性肥胖大鼠的减肥作用

研究洋葱皮提取物对营养性肥胖大鼠的减肥作用。采用营养性肥胖模型法,选取茶多酚为阳性对照,分别以茶多酚0.57%、洋葱皮提取物1.33%比例添加于营养饲料中,饲喂营养性肥胖模型大鼠,研究洋葱皮提取物对营养性肥胖模型大鼠的体重、Lee’s指数、摄食量、食物利用率的影响;对洋葱皮提取物的减肥功能进行评价。结果表明,洋葱皮提取物具有控制体重增长的作用;并能有效抑制脂肪细胞膨大,减少体内脂肪堆积。     

Purification and identification of rambutan (Nephelium lappaceum) peel phenolics with evaluation of antioxidant and antiglycation activities in vitro

The crude rambutan peel phenolic (RPP) extracts were purified by resin adsorption technology. NKA‐9 resin with the best adsorption capacity and desorption ratio was chosen to dynamically purify crude RPP. Adsorption capacity and desorption ratio of NKA‐9 resin were 91.85 mg gallic acid equivalent (GAE) g^?1 and 90.45%, respectively. Purification processes enriched total phenolic content, and the contents in crude and purified RPP were 579.72 and 877.11 mg GAE g^?1 extract powder, respectively. Phytochemical compounds of RPP were qualitatively and quantitatively indentified by mass spectrometry. Purification of the resin as expected elevated the concentrations of major phenolic compounds, especially geraniin and ellagic acid. Antioxidant and antiglycation activities of crude and purified fractions were evaluated in vitro. Crude and purified RPP had high inhibitory effects on oxidation and glycation, and purified RPP showed stronger bioactivity than crude RPP (P < 0.05), which might be due to their differences in phenolic profiles.     

Original article: Thermal and light degradation kinetics of anthocyanin extracts from mangosteen peel (Garcinia mangostana L.)

The stability and half‐life time of anthocyanin extracts from mangosteen peel were studied under controlled oxygen supply, undergoing the influence of light source (fluorescent, incandescent, infrared and ultraviolet) and storage temperature (5, 28, 40 and 50 °C). The kinetic parameters for anthocyanin degradation, under different illumination conditions fit the first‐order reaction model, and the exposition under fluorescent light resulted in a higher half‐life time (597 h), followed by incandescent (306 h), ultraviolet (177 h) and infrared (100 h). The kinetic behaviour for the storage in different temperatures also fit the first order, and at 5 °C the highest half‐life time (4006 h) was found, followed by 28 °C (370 h), 40 °C (125 h) and 50 °C (93 h). The activation energy was 14.7 Kcal.mol^?1, and Q₁₀ values showed that at 5 °C the anthocyanin extracts were more sensitive to storage temperature changes compared to the other tested temperatures.     

In vitro and in vivo satietogenic effect of yeast extracts and control of food intake in rats

Yeast extracts, by their nutritional characteristics, have a high potential as a source of biologically active molecules and functional food ingredients. In this work, in vitro and in vivo satietogenic effect of yeast extracts was examined. The in vitro results obtained for the first time showed that a yeast extract strongly stimulated the secretion of cholecystokinin (CCK) from endocrine STC-1 cells. The effects obtained with this yeast extract were compared to those obtained with other food products known for their potential involvement in satiety (milk proteins, soybean). This yeast extract showed a stronger ability to stimulate CCK secretion than all other products tested. Lack of toxicity of this yeast extract was demonstrated through cell proliferation assays. In vivo, the tests in rats confirmed the satietogenic potential of this yeast extract, particularly in terms of food intake and weight loss, but also for hormone levels.     

乳酸菌发酵豆乳体内外抗氧化效应研究

通过对体内外抗氧化效应比较,探讨了嗜热链球菌(Streptococcus thermophilus)grx90发酵豆乳的抗氧化活性。结果表明,豆乳(SM)、活菌豆乳(SMC)、发酵豆乳(FSM)、巴氏杀菌发酵豆乳(PFSM)清除DPPH能力和亚铁离子螯合能力存在不同程度差异性,发现FSM体外抗氧化作用显著高于PFSM、SMC和SM;FSM显著降低了急性酒精肝损伤模型小鼠血清ALT和AST,提高了肝组织中SOD和GSH-Px活性,并显著降低肝组织中MDA含量。体内外实验进一步证实了发酵豆乳抗氧化活性的增强主要是基于乳酸菌活菌体及其代谢产物,并通过增强机体抗氧化酶活性,降低过氧化物的积累以增强抗氧化能力,从而实现对酒精诱导小鼠急性氧化损伤的保护作用。     

Effects of dietary fat level on the xenobiotic metabolism enzymes activity and antioxidant enzymes in rats

Male Wistar rats received fat-free diet or diets containing 5, 10 and 30% of fat (sunflower oil + lard, 1:1) for 4 weeks. The direct relationship between dietary fat level and ethoxyresorufin O-dealkylase activity of CYP1A1, methoxyresorufin O-dealkylase activity of CYP1A2, pentoxyresorufin O-dealkylase activity of CYP2B1 and testosterone 6beta-hydroxylase activity of CYP3A was found. Activities of key enzymes of phase II xenobiotic metabolism (total activity of glutathione transferase, activity of UDP-glucuronosyle transferase) and antioxidant enzymes (catalase, glutathione peroxidase, glutathione reductase, paraoxonase-1 and heme oxygenase-1) also increased with higher dietary fat level.     

山竹果皮中多酚类物质的抗氧化性研究

以新鲜山竹为原料,对山竹果皮中的总多酚含量进行了测定,并对不同相多酚提取物的抗氧化性进行了研究。结果表明：山竹果皮中总多酚含量为36.9mgGAE/gFW,其中多酚浓度达到16.5μg/mL时,有机相多酚对DPPH（1,1-二苯基-2-三硝基苯肼）自由基的清除能力达51.7%,水相多酚对DPPH自由基的清除能力达76.9%。水相多酚比有机相多酚更具备将Fe3＋还原的能力。当贮藏18d时,添加0.06%有机相多酚的猪油POV（过氧化值）为13.8meq/kg,添加0.06%水相多酚的猪油POV为16.7meq/kg,多酚提取物添加量为0.06%时,其抗氧化效果与添加0.04%VC的效果相当。由此可知,山竹果皮多酚提取物具有良好的体外抗氧化作用,并且水相中的多酚类物质比有机相中的多酚类物质的抗氧化性更强。     

Effects of drying methods on assay and antioxidant activity of xanthones in mangosteen rind

Rind of mangosteen is one of the best natural sources of xanthones, which have been reported to have high antioxidant activity. In many cases mangosteen rind must be dried prior to extraction of the active compounds. However, information on the effects of different drying methods and conditions on the retention of xanthones in mangosteen rind is still very limited. This work was therefore aimed at studying the effects of selected drying methods and conditions on the changes of the contents as well as the antioxidant activity of xanthones in mangosteen rind. Mangosteen rind was subject to hot-air drying, vacuum drying or low-pressure superheated steam drying (LPSSD) at 60, 75 and 90 °C and in the case of sub-atmospheric drying methods at an absolute pressure of 7 kPa. The xanthones contents were analysed by HPLC, while their antioxidant activity was assessed by DPPH radical scavenging capacity and ABTS assays. The results showed that the drying methods significantly affected degradation of xanthones (i.e., α-mangostin and 8-desoxygartanin) and their antioxidant activity. Either hot-air drying or LPSSD at 75 °C is proposed as an appropriate drying technique and condition to preserve xanthones in mangosteen rind.     

Characterization and antioxidant activities of procyanidins from lotus seedpod,mangosteen pericarp,and camellia flower

A highly sensitive high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry method was established for the identification of procyanidin components in the lotus seedpod, mangosteen pericarp, and camellia flower. It was shown that the main procyanidins of lotus seedpod were monomer, dimmer, and trimer-procyanidins, in which dimers and trimers were in the majority (80.8%). However, mangosteen pericarp and camellia flower procyanidins were mostly composed of monomers (47.7 and 62.4%, respectively). In addition, their antioxidant activities were also compared and the strongest antioxidant activities were found in lotus seedpod (1,1-diphenyl-2-picrylhydrazyl: 1.57 μmol Trolox equivalent/g dry weight; 2’-azino-bis-(3-ethyl-benzthiazoline-6-sulphonate acid): 1.23 μmol Trolox equivalent/g dry weight; Fe²⁺/H₂O₂: 2.17 μmol Trolox equivalent/g dry weight), followed by mangosteen pericarp and camellia flower. Moreover, the lotus seedpod, mangosteen pericarp, and camellia flower extracts exhibited considerable dose-dependent protective effects on the H₂O₂-induced damage of human umbilical vein endothelial cells. Among them, lotus seedpod extracts showed relatively stronger cell-based antioxidant enzyme activities and lower contents of malondialdehyde and nitric oxide than those of camellia flower and mangosteen pericarp. From these results, lotus seedpod, mangosteen pericarp, and camellia flower would be available agricultural wastes and their utilization may produce easier access of functional ingredients for medicinal exploration.     

Evaluation of Citrus aurantifolia peel and leaves extracts for their chemical composition,antioxidant and anti‐cholinesterase activities

BACKGROUND: The replacement of synthetic antioxidants by safe natural antioxidants fosters research on the screening of vegetables and food as sources of new antioxidants. Moreover, oxidative degeneration of cells is associated with neurodegenerative diseases such as Alzheimer's disease. On the basis of these considerations this work aimed to investigate the antioxidant properties [by using the diphenyl picryl hydrazyl, 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid) and ferric reducing ability of plasma assays, and the β‐carotene bleaching test] and the anti‐cholinesterase activity of Citrus aurantifolia peel and leaves from different areas of growth. RESULTS: Methanol extracts of the peel and leaves demonstrated the strongest radical scavenging activity. A similar trend was observed with the reducing ability, with values from 112.1 to 146.0 µmol L^?1 Fe(II) g^?1. The relationship between phenol and flavonoid contents and antioxidant activity was statistically investigated. Based on analysis by high‐performance liquid chromatography, the most abundant flavonoids found in C. aurantifolia extracts were apigenin, rutin, quercetin, kaempferol and nobiletin. n‐Hexane fractions of both peel and leaves showed a good acetylcholinesterase inhibitory activity with IC₅₀ values in the range 91.4‐107.4 µg mL^?1. Gas chromatography‐mass spectrometry analysis revealed the presence of monoterpenes and sesquiterpenes as most common components. CONCLUSION: The findings of this study suggest a potential use of C. aurantifolia peel and leaves for supplements for human health. Copyright © 2012 Society of Chemical Industry     

Assessment of in vitro antioxidant, antibacterial and immune activation potentials of aqueous and ethanol extracts of Phyllanthus niruri

BACKGROUND: Recently much attention has been paid to biologically active plants because of their low production cost and fewer adverse effects compared with chemical drugs. In the present investigation the bioactivity of Phyllanthus niruri ethanol and aqueous extracts was evaluated in vitro. RESULTS: The ethanol extract of P. niruri showed a high level of flavonoid content (123.9 ± 0.002 mg g^?1), while the aqueous extract showed the highest 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH; IC₅₀6.85 ± 1.80 µmol L^?1) and 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid) (ABTS; 46.44 ± 0.53 µmol L^?1) free radical scavenging activities with high phenol content (376 ± 0.02 mg g^?1) and elevated levels of ferric reducing antioxidant power (FRAP; 23 883 ± 0.019 mmol g^?1) with excellent antibacterial activity against Staphylococcus aureus (20 mm inhibition zone) and Streptococcus agalactiae (12 mm inhibition zone), respectively, in addition to the best immune activation potential of human peripheral blood mononuclear cells (450.5%). CONCLUSIONS: It is clear from our results that both extracts of P. niruri has excellent bioactivity roles via elevated levels of antibacterial, antioxidant and percentage of peripheral blood mononuclear cell proliferation, which could lead to the development of medications for clinical use. Copyright © 2012 Society of Chemical Industry