鸡眼草3种不同溶剂提取物对ABTS自由基和羟自由基清除活性的研究

目的:研究鸡眼草3种不同溶剂提取物对ABTS自由基(ABTS·+)和羟自由基(·OH)的清除活性。方法:用冷浸法得到鸡眼草乙醇、丙酮和乙酸乙酯提取物,以UV法测定3种提取物的总黄酮含量,并测定3种提取物对ABTS·+和·OH的清除活性。结果:鸡眼草丙酮提取物的总黄酮含量最高(131.41mg·g-1),对自由基的清除效果也最好,其对ABTS·+和·OH的清除率最高可达到88.79%和95.81%。结论:鸡眼草乙醇、丙酮和乙酸乙酯提取物都具有较强的自由基清除能力,有作为天然抗氧化剂开发利用的潜力。     

Antigenotoxic and Free Radical Scavenging Activities of Extracts from Moricandia arvensis

This study evaluates genotoxic and antigenotoxic effects of extracts from leaves of Moricandia arvensis, which are used in traditional cooking and medicines. Extracts showed no genotoxicity when tested with the SOS Chromotest using E. coli PQ37 and PQ35 strains, except for the total oligomers flavonoids enriched extract. Petroleum ether and methanol extracts are the most active in reducing nitrofurantoin genotoxicity, whereas methanol and total oligomers flavonoids enriched extracts showed the most important inhibitory effect of H₂O₂ genotoxicity. In addition, these two extracts showed important free radical scavenging activity toward the DPPH^· radical, whereas the chloroform extract exhibited the highest value of TEAC against ABTS^+· radical.     

Free Radical Scavenging Activity of Extracts from Thai Plants in Guttiferae and Schisandraceae Families

ABSTRACT

Five Thai plants from the Guttiferae (Hypericum hookerianum. Wight & Arn, Garcinia speciosa. Wall, Garcinia xanthochymus. Hook f. ex. T. Anderson, Cratoxylum formosum. ssp. pruniflorum. (Kurz) Gogel, and Calophyllum polyanthum. Wall ex Choisy) and one from the Schisandraceae (Schisandra verruculosa.) were extracted by methanol and chloroform. The extracts were screened for free radical scavenging activity using the DPPH assay. All extracts showed a dose-dependent antioxidant activity. The most potent with the lowest IC₅₀ values were observed in the methanol extracts from the wood of G. speciosa., which were 2.5- and 5.3-fold more potent than the two standard antioxidants, ascorbic acid and α.-tocopherol, respectively. Free radical scavenging activities ranging from moderate to high were observed in both methanol and chloroform extracts from H. hookerianum., C. formosum. ssp. pruniflorum., G. xanthochymus., S. verruculosa. and C. polyanthum.. The information from this study can explain the traditional use and the further development of these extracts into new pharmaceuticals.     

Antioxidant and Free Radical Scavenging Effects of Lippia nodiflora

This study evaluated the in vitro antioxidant potential of methanol extract of Lippia nodiflora Mich. (Verbenaceae) (MELN). The different antioxidants assays, including total antioxidant activity, reducing power, free radical, superoxide anion radical, hydroxyl radical, hydrogen peroxide, nitric oxide scavenging, and total phenolic content, were studied. MELN exhibited potent total antioxidant activity that increased with increasing amount of extract concentration (50, 100, 200, and 400 μg/mL), which were compared with standard drug α -tocopherol (400 μg/mL). The different concentrations of MELN and α -tocopherol showed inhibition of 49.07%, 58.96%, 63.07%, 68.29%, and 74.59%, respectively, on peroxidation in linoleic acid emulsion. In addition, MELN had effective reducing power, free radical scavenging, superoxide anion radical scavenging, hydroxyl radical scavenging, hydrogen peroxide radical scavenging, and nitric oxide scavenging activity, and total phenolic content depending on concentration. These various antioxidant activities were compared with standard antioxidants such as BHA, BHT, catechin, and α -tocopherol.     

Free Radical Scavenging and Hepatoprotective Constituents from the Leaves of Juglans sinensis

In the course of searching for hepatoprotective agents from natural products, six compounds were isolated from the MeOH extract of the leaves of Juglans sinensis, as guided by their DPPH free radical scavenging activity. The structures were determined as juglanoside B (1), quercetin 3-O-alpha-L-arabinofuranoside (avicularin, 2), quercetin 3-O-alpha-L-arabinopyranoside (guaijaverin, 3), quercetin 3-O-alpha-L-rhamnopyranoside (quercitrin, 4), (+)-catechin (5) and quercetin 3-O-beta-D-galactopyranoside (hyperin, 6). Compounds 2-6 showed significant DPPH free radical scavenging effects. An evaluation for the hepatoprotective activity of the isolated compounds on drug-induced cytotoxicity was conducted, and compounds 1, 2, and 5 showed protective effects against nitrofurantoin-induced cytotoxicity, and compound 5 also exhibited a moderate protective effect on amiodarone-induced cytotoxicity in Hep G2 cells.     

Hesperitin Esters: Highly Stable Flavanones with Both Free Radical Scavenging and Anti-Elastase Activities

Abstract

In targeting molecules, destinated for treatment of skin ageing, we synthesized esters of hesperitin (4′-methoxy-5,7,3′-trihydroxyflavanone). Esterification with lauric acid was used with the aim to overcome the flavonoid instability and to improve the therapeutic usefulness. Stability, free radical scavenging activity and anti-elastase potency of the prepared compounds were studied and compared to those of hesperitin (natural compound). Compounds obtained are more stable than hesperitin and display similar or higher anti-elastolytic and free radical scavenging activities.     

仙茅苷对自由基的清除作用

目的研究仙茅(Curculigo orchioidesGaertn.)主要成分仙茅苷(curcu ligoside)对羟自由基和超氧阴离子自由基的清除作用。方法分别采用比色法及电子顺磁共振技术(ESR)测定仙茅苷对羟自由基和超氧阴离子自由基的清除效果。结果仙茅苷对羟自由基和超氧阴离子自由基均有良好的清除作用,其清除率略低于茶多酚。结论仙茅苷对自由基具有明显的清除作用,是一种有效的天然抗氧化剂。     

水杉皮中Agatharesinol的分离鉴定及清除自由基活性

目的：研究水杉树皮中的化学成分和生物活性。方法水杉皮采用60％乙醇提取,经大孔树脂、Sephadex LH-20和制备HPLC分离获得化合物,结构采用1 H NMR和13 C NMR光谱技术鉴定。采用DPPH测定化合物的清除自由基活性。结果分离获得化合物为木质素 Agathares-inol,其能浓度依赖性地清除DPPH自由基。结论首次对水杉皮中的木质素成分进行了研究,从中分离获得具有清除自由基活性的 Agathares-inol。     

Novel Flavanone Glucoside with Free Radical Scavenging Properties from Galium fissurense

Abstract

From the herb of Galium fissurense, a new flavanone glucoside was isolated and characterized as 5,7,3′-trihydroxy-flavanone-4′-O-β-D-glucopyranoside (1) from spectroscopic evidence. In addition, three known compounds (luteolin, apigenin-7-O-β-D-glucopyranoside, naringenin-7-O-β-D-glucopyranoside) were isolated for the first time from this plant. The free radical scavenging properties of the four compounds were studied by use of in vitro electron spin resonance spectrometry. The new compound showed potent antioxidant activity.     

Radical Scavenging Activity of Methanol Leaf Extracts of Orthosiphon stamineus.

Abstract

The antioxidant activity of methanol extracts of Orthosiphon stamineus. Benth (Lamiaceae), cultivated in different regions of Malaysia, was determined by measuring the scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and on superoxide anion. The results showed a variation in free-radical and superoxide-anion scavenging activities of the methanol extracts ranging from 62.82 to 92.34% and 53.29 to 75.88%, respectively. Methanol extract was active, and its antioxidative potency was comparable to that of pure quercetin and higher than that of the widely used synthetic antioxidant butylated hydroxylanisole (BHA). The UV and HPLC chromatographic fingerprints of the major phenolics were qualitatively similar for all the methanol leaf extracts of Orthosiphon stamineus. from various locations.     

Superoxide Radical Scavenging Properties of Extracts and Flavonoids Isolated from the Leaves of Blumea balsamifera

In view of the pharmacological interest in flavonoids, the superoxide radical scavenging capacity of pet-ether, chloroform, and methanol extracts and flavonoids of Blumea balsamifera DC leaves on nonenzymatically (phenazine methosulfate/NADH) generated superoxide radicals were evaluated. The methanol extract (93.91 ± 1.37%) exhibited higher radical scavenging activity than the chloroform extract (84.58 ± 1.51%). The pet-ether extract was inactive toward nonenzymatically generated superoxide radicals. The superoxide radical scavenging capacity of flavonoids (100 µM) as determined was decreased in the order quercetin > luteolin > 5,7,3′,5′-tetrahydroxyflavanone > blumeatin > rhamnetin > tamarixetin > luteolin-7-methyl ether > dihydroquercetin-4′-methyl ether > dihydroquercetin-4′,7-dimethyl ether. It was concluded that flavonoids with a free hydroxyl group were more active than methylated compounds, and the flavonoid content of extracts contributed to their superoxide radical scavenging activity.     

四物口服液对羟基自由基的清除作用

目的 评价四物口服液体外对羟基自由基的清除作用.方法 采用荧光分光光度法,过氧化氢溶液与不同浓度的四物口服液稀释、混匀,254 nm紫外光照射后加入苯甲酸溶液,室温放置后在激发波长304 nm、发射波长401 nm条件下测定荧光强度,用羟基自由基清除率IC50（荧光强度降低50％时药物浓度）作为四物口服液对羟基自由基清除率大小的评价指标.结果 四物口服液体外对羟基自由基清除率IC50为0.009 3倍原药.结论 四物口服液具有体外清除羟基自由基的作用.     

茉莉花挥发油清除自由基活性的研究

目的：从清除1,1－二苯基－2－苦苯肼自由基（DPPH?）、羟自由基（? OH）、超氧阴离子自由基（O2?－）3个方面,研究茉莉花挥发油清除自由基活性。方法采用水蒸气蒸馏法提取茉莉花挥发油,从其清除DPPH?、? OH和O2?－能力3个方面进行考察,并以常用抗氧化剂L－抗坏血酸为对照作比较,通过计算半数抑制浓度（ IC50）评价茉莉花挥发油清除,在供试质量浓度范围内,呈一定量效关系,其 IC50分别为153．548μg?mL －1、56．481μg? mL －1和133．586μg? mL －1。结论茉莉花挥发油具有良好的清除自由基活性,是一种新型天然抗氧化物质来源。     

滋泉口服液清除氧自由基和抗脂质过氧化作用

目的研究滋泉口服液抗氧化的作用机理。方法采用体外氧自由基和羟自由基诱导的小鼠心肌匀浆脂质过氧化反应,评价抗氧化作用。结果滋泉口服液可清除次黄嘌呤黄嘌呤氧化酶系统产生的超氧阴离子(SAFR)和Fenton反应生成的羟自由基(HFR),并能抑制HFR诱导的小鼠心肌匀浆脂质过氧化作用。结论滋泉口服液具有抗氧化作用。     

南沙参多糖对小鼠的抗衰老及清除氧自由基作用研究

目的:探讨南沙参多糖对老龄小鼠的抗衰老作用及清除氧自由基作用.方法:考察用药前后老龄小鼠肝、脑脂褐素、血中皮质醇、睾酮含量和肝、脑中单胺氧化酶活性的变化,以及南沙参多糖对老龄小鼠体内超氧化物歧化酶、丙二醛和谷胱甘肽过氧化物酶和体外直接清除氧自由基的作用.结果:1.0 g·kg-1南沙参多糖明显降低老龄小鼠肝、脑脂褐素含量,并增加老龄小鼠血清中睾酮的含量,同时可使老龄小鼠肝、脑中B型单胺氧化酶的活性降低.这些效应与其抑制老龄小鼠血清中丙二醛的生成、提高其红细胞中超氧化物歧化酶及全血中谷胱甘肽过氧化物酶的活性和直接清除体外氧自由基关系密切.结论:南沙参多糖对于老龄小鼠有明显的抗衰老效应.     

不同提取方式对金线莲多糖含量及DPPH自由基清除活性的影响

目的考察不同提取方式对金线莲多糖含量、结构及抗氧化活性的影响。方法采用热水回流提取法、超声提取法和酶法分别提取金线莲多糖,苯酚硫酸法测定多糖含量,刚果红实验检测三螺旋结构,采用DPPH自由基清除实验评价其抗氧化活性。结果不同提取方式对多糖的产率和DPPH清除活性均有影响,其中超声提取和酶解提取得到的多糖DPPH自由基清除活性优于热水回流提取所得金线莲多糖;提取所得金线莲多糖不含三螺旋结构。结论综合考虑提取效率、抗氧化活性和工艺成本,超声提取为最优方法。     

Free Radical Scavenging Activity of Calotropis gigantea on Streptozotocin-Induced Diabetic Rats

Swarnabhasma, an Ayurvedic preparation containing Calotropis gigantea R. Br. (Asclepiadaceae) is extensively used by Ayurvedic physicians for treatment of diabetes mellitus, bronchial asthma, rheumatoid arthritis and nervous disorders. In the present study, we report the effect of chloroform extracts of Calotropis gigantea leaf and flower on free radical scavenging activity, and lipid profile in streptozotozin-induced diabetic rats. The lipid peroxidation, superoxide dismutase, and catalase were measured in liver homogenate and serum glutamic pyruvic transaminase, serum glutamic oxaloacetic transaminase, alkaline phosphatase, lipid profile were measured in blood serum. Administration of single dose of streptozotozin (55 mg/kg, i.p.) caused significant increases in lipid peroxidation, serum glutamic pyruvic transaminase, serum glutamic oxaloacetic transaminase, alkaline phosphatase, cholesterol and triglyceride levels, while superoxide dismutase and catalase levels were significantly decreased. Further, administration of chloroform extracts of Calotropis gigantea leaf and flower to streptozotocin-induced diabetes rats at a dose of 10, 20 and 50 mg/kg orally for 27 d lead to a significant decrease in lipid peroxidation, serum glutamic pyruvic transaminase, serum glutamic oxaloacetic transaminase, alkaline phosphatase, cholesterol and triglyceride levels. Consequently, superoxide dismutase and catalase levels were significantly increased. Glibenclamide was used as a positive control (10 mg/kg). It was observed that the effect of chloroform extracts of Calotropis gigantea on alkaline phosphatase, cholesterol, superoxide dismutase, serum glutamic pyruvic transaminase, serum glutamic oxaloacetic transaminase, levels are comparable to that of those produced by the positive control.     

Lignan Production by Cell Cultures of Linum setaceum. and Linum campanulatum.

Abstract

Callus and suspension cultures of Linum campanulatum. L. and Linum setaceum. Brot. (Linaceae) were established to study accumulation of lignans. Justicidin B proved to be the main constituent in the callus and suspension cultures of Linum campanulatum. L. Phytochemical analysis of cell cultures of Linum setaceum. Brot. has demonstrated that callus produces yatein, desoxypodophyllotoxin, and β.-peltatin, whereas the suspension cultures contain yatein, desoxypodophyllotoxin, β.-peltatin, and 6-methoxypodophyllotoxin.