Radical scavenging activity and composition of raspberry (Rubus idaeus) leaves from different locations in Lithuania

Raspberry (Rubus idaeus) leaves, collected in different locations of Lithuania were extracted with ethanol and the extracts were tested for their antioxidant activity (AA) by using ABTS(.)(+) decolourisation and DPPH(.) scavenging methods. All extracts were active, with radical scavenging capacity at the used concentrations from 20.5 to 82.5% in DPPH(.) reaction system and from 8.0 to 42.7% in ABTS(.)(+) reaction. The total amount of phenolic compounds in the leaves varied from 4.8 to 12.0 mg of gallic acid equivalents (GAE) in 1 g of plant extract. Quercetin glucuronide, quercetin-3-O-glucoside and rutin were identified in the extracts.     

Antimicrobial and free radical scavenging activities of Teucrium montanum

The antimicrobial and free radical scavenging activities of petroleum ether, chloroform, ethyl acetate, n-butanol and water extracts of Teucrium montanum were investigated. Ethyl acetate, chloroform and n-butanol extracts expressed a wide range of inhibiting activity against both Gram (+) and Gram (-) bacteria. n-Butanol extract possessed potent DPPH free radical scavenging activity.     

12个楸树无性系叶片多酚含量与抗氧化活性

自由基具有强氧化性,机体衰老及多种疾病如肿瘤、炎症、神经退行性疾病、动脉粥样硬化等的诱发促进机制都与自由基有关[1]。自由基的减少,不仅要靠自身的清除系统,还需要外部抗氧化剂的协助。近年来,关于合成抗氧化剂的副作用受到人们更多的关注,因此,寻找安全、高效的植物源类抗氧化剂,已成为食品领域研究的热点。楸树(Catalpa bungei C.A.Mey.)为紫葳科(Bignoniaceae)梓属植物,落叶乔木,《本草纲目》记载楸树树皮、叶具有药     

Apoptotic and free radical scavenging properties of the methanolic extract of Gentianella alborosea

Gentianella alborosea ("Hercampure") is a Peruvian species used in folk medicine for the treatment of a variety of health disorders. We tested the free radical scavenging (DPPH) and induction of apoptosis on a human uterus tumor cell line (HeLa) by its methanolic extract. The results showed a noticeable radical scavenging activity and a dose-dependent apoptotic effect.     

Antioxidant activity of Pyrrosia petiolosa

The ethanol extract of Pyrrosia petiolosa showed an antioxidant activity as determined by free radical scavenging, superoxide radical scavenging, lipid peroxidation, and hydroxyl radical-induced DNA strand scission assays.     

Antioxidant activity of nine Fabaceae species growing in Serbia and Montenegro

The aim of this study was to investigate antioxidant capacity of nine Fabaceae species collected on the mountains of Serbia and Montenegro. Antioxidant assays with various reaction mechanisms were used, including total phenolic content by Folin-Ciocalteu, DPPH radical scavenging capacity, Trolox equivalent antioxidant capacity (TEAC) values by ABTS radical cation and inhibition of liposome peroxidation. The investigated plants exhibited strong antioxidant capacity in all the tested methods, and among them, Lathyrus binatus, Trifolium pannonicum, and Anthyllis aurea were found to be the most active.     

Evaluation of Pluchea carolinensis extracts as antioxidants by the epinephrine oxidation method

Many methods have been used to evaluate synthetic and natural products as hydroxyl radical scavengers. In this study a spectrophotometric method to evaluate the scavenger activity of the hydroxyl radical produced in Fenton reaction is proposed. The oxidation of l-epinephrine to adrenochrome permitted the detection of the hydroxyl radical by spectrophotometry and its possible scavenging by hydroquinone, a well known antioxidant. The method was used to evaluate the antioxidant activity of Pluchea carolinensis leaves.     

Effect of Garcinia mangostana on inflammation caused by Propionibacterium acnes

The present study was aimed to investigate the activity of Thai medicinal plants on inflammation caused by Propionibacterium acnes in terms of free radical scavenging and cytokine reducing properties. P. acnes have been recognized as pus-forming bacteria triggering an inflammation in acne. Antioxidant activity was determined by DPPH scavenging and NBT reduction assay. The result showed that Garcinia mangostana possessed the most significant antioxidant activity and reduced reactive oxygen species production. Houttuynia cordata, Eupatorium odoratum, and Senna alata had a moderate antioxidant effect. In addition, Garcinia mangostana extracts could reduce the TNF-alpha production as determined by ELISA. Garcinia mangostana was highly effective in scavenging free radicals and was able to suppress the production of pro-inflammatory cytokines. This study has identified the promising source of anti-inflammatory agent which could be useful in treatment of acne vulgaris.     

Radical scavenging capacity of Agrimonia eupatoria and Agrimonia procera

The antioxidant activity of Agrimonia eupatoria (Agrimony) and Agrimonia procera (Fragrant agrimony) extracts was assessed by measuring in DPPH radical scavenging and ABTS(+) radical decolourisation reaction systems. Radical scavenging capacity of agrimony extracts varied in a wide range (9.1-97.5% in DPPH reaction and 6.7-79.5% in ABTS reaction) depending on the polarity of the solvent used to obtain the extract.     

Phytochemical and antioxidant analysis of eight Hypericum taxa from Central Italy

Eight taxa of the Hypericum spp. growing in Central Italy (Appennino Umbro-Marchigiano) were analyzed by HPLC-DAD for constituents quantitation, for antioxidant and free radical scavenging activities. H. perforatum subsp. veronense was the richest in phenolic compounds and hyperforin was detected for the first time in H. hircinum subsp. majus. Significant values of antioxidant activity were found in the investigated Hypericum taxa.     

Tannins from barks of Pinus caribaea protect Escherichia coli cells against DNA damage induced by gamma-rays

This work was aimed to evaluate genotoxicity and antigenotoxicity activity against gamma-rays of a tannin fraction obtained from barks of Pinus caribaea, as well as to elucidate the antigenotoxic mechanisms involved in radioprotection by using different approaches as pre-, co- and post-irradiation cell treatments with plant extract. The tannin fraction was not genotoxic to Escherichia coli cells in experiments using different exposure times. This extract was antigenotoxic against gamma-rays when the cells were pre- or co-treated with this extracts, but not during post-irradiation treatments, suggesting a possibly antigenotoxic action through free radical scavenging mechanisms. The results are discussed in relation to the chemopreventive and therapeutic potential of the studied plant species.     

Phenolic constituents and the in vitro antioxidant activity of the flowers of Hypericum venustum

The phenolic constituents and antioxidant activity of ethanol and water extract of the flowers of Hypericum venustum, collected in Turkey, were investigated. The extracts possess strong reducing power, free radicals and hydrogen peroxide scavenging activity, as well as metal chelating ability.     

Antioxidant activity of Filipendula hexapetala flowers

The antioxidant activity of the methanol extract of Filipendula hexapetala flowers was assessed by the assay for ferric-reducing antioxidant power (FRAP), the assay for DPPH free radical scavenging ability (DPPH) and the assay for the influence of lipid peroxidation in liposomes, induced by Fe(2+)/ascorbate system and measured by the TBA test (LP). The activity of the investigated extract in all test-systems was found to be significant. The principal constituent responsible for the observed effects was isolated and identified as spiraeoside.     

Comparison of bioactive compounds content, free radical scavenging and anti-acne inducing bacteria activities of extracts from the mangosteen fruit rind at two stages of maturity

Contents of bioactive components, free radical scavenging and anti-acne producing bacteria activities of young and mature fruit rind extracts of mangosteen were compared. The young fruit rind extract contained significantly higher contents of phenolics and tannins and promoted higher free radical scavenging activity than the mature fruit rind extract, while the later extract contained higher contents of flavonoids and α-mangostin xanthone and gave higher anti-acne producing bacteria activity than the young fruit rind extract. Thus, the young and mature stages of mangosteen fruit rind should be beneficial for further development of antioxidant and anti-acne pharmaceutical preparations, respectively.     

香椿叶提取物清除DPPH自由基能力的测定方法

建立了以分光光度法测定天然抗氧化剂清除2,2-二苯基-1-苦肼基(DPPH)自由基能力的方法。通过测定芦丁、檞皮素、抗坏血酸、没食子酸的DPPH自由基清除率曲线,提出以IC50值作为评价试样清除DPPH自由基能力的指标,并将此应用于测定香椿叶提取物清除DPPH自由基的能力。通过测定香椿叶提取物与DPPH溶液反应后,DPPH溶液在517 nm处的吸光度的变化,确定了测定香椿叶提取物清除DPPH自由基能力的条件。即:测定波长517 nm,反应时间50 m in。在此条件下测得的以总黄酮计的香椿叶提取物清除DPPH自由基的IC50值为22.026。     

A new flavonoid glycoside from the leaf of Cephalotaxus koreana

A new flavone glycoside, apigenin 5-O-alpha-L-rhamnopyranosyl-(1-->3)-beta-D-glucopyranoside (1), along with four known flavonol glycosides (2-5), were isolated from the leaf of Cephalotaxus koreana. The new glycoside 1 showed inhibitory activity in superoxide radical scavenging assay with IC(50) value of 13.0 microM, while it showed weak activity in 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay. Compounds 2-5 exhibited antioxidant activity in scavenging DPPH and superoxide radicals with IC(50) values ranging from 5.7 to 22.3 microM.     

一个新培育的小蜡花叶嵌合体——‘新顺’

对福建农林大学校园小蜡绿篱中发现的一个小蜡花叶变异枝进行培育,得到了一个小蜡的花叶栽培变种,定名为'新顺'(Ligustrumsinense'XinShun')。描述'新顺'的植物学特征、栽培性状和园林用途。'新顺'叶片由金黄色的表层包被着绿色心层或包围着表层裸露的绿色心层组成。'新顺'叶片具有花叶性状,因而比小蜡更具观赏性,凡适合小蜡栽培的地方都适合'新顺'的栽培。园林应用上可以作为模纹花坛,花叶小蜡绿篱或花叶小蜡球,盆栽或制作盆景。     

山楂叶总黄酮清除DPPH和超氧阴离子自由基的活性研究

以山楂秋日落叶为原料,70%乙醇为溶剂,提取得到山楂叶总黄酮。以芦丁和VC为对照,采用分光光度法研究了山楂叶总黄酮对DPPH自由基和超氧阴离子自由基的体外清除活性。结果表明,山楂叶总黄酮对DPPH自由基和超氧阴离子自由基均具有一定的清除作用。对DPPH自由基的清除率随加入量的增加而增加,当加入量为2 mg时,清除率为50.29%;而对超氧阴离子自由基的清除在加入量为1.2 mg时达到最高值27.36%。芦丁对二自由基的最高清除率分别为63.83%和32.55%;而VC则分别为69.93%和99.04%。经比较发现,山楂叶总黄酮的清除自由基活性稍低于芦丁,远低于VC。     

New icetexane diterpenes with intestinal α-glucosidase inhibitory and free-radical scavenging activity isolated from Premna tomentosa roots

New icetexane diterpenes (1-2); 8, 11, 13-icetexatriene-10-hydroxy, 11, 12, 16-tri acetoxyl (1) and 8, 11, 13-icetexatriene-7, 10, 11-dihydroxy-12, 13-dihydrofuran (2) along with six known compounds namely acetoxy syranzaldehyde (3), syranzaldehyde (4), coniferaldehyde (5), lupeol (6), betulin (7), and 4-(4-methoxy phenyl)-2-butanone (8) were isolated from the roots of Premna tomentosa. The structures of compounds 1 and 2 were established by detailed spectral analysis using UV, IR, ¹H NMR, ¹³C NMR, 1D, 2D and Mass. The newly isolated compounds were screened for rat intestinal α-glucosidase inhibitory and free radical (DPPH) scavenging potentiality. The new icetexane diterpenes (1, 2) and compound 3 were found to have significant α-glucosidase inhibitory and also free radical scavenging (DPPH) activities.     

Free radical scavenging activity of extracts prepared from fresh leaves of selected Chinese medicinal plants

The free radical scavenging activity of the 80% methanolic extracts from fresh leaves of 300 Chinese medical woody plants was assessed with the aid of the stable DPPH radical. Among the plants screened, 56 species had strong free radical scavenging capacities, with IC50 values lower than 0.5 mg leaves per milliliter. Analysis of the medical uses of these plants showed that most of them are employed for their effects on hemostasis, as anti-inflammatory, antimicrobial or for treatment of dysentery. These uses may be directly linked to the content in tannins and flavonoids and consequently to their free radical scavenging activities.