Chemical Constituents in Extracts from Leaves of Lantana trifolia and Their In Vitro Anti-oxidative Activity

Objective To isolate, purify, and analyze the anti-oxidants from the leaves of Lantanatrifolia. Methods The anti-oxidative activities of the crude extracts from liquid-liquid extraction of L. trifolia leaves were assayed by 1,1-diphenyl-2-picrylhydrazyl(DPPH) method to assess their radical scavenging and reducing abilities. The total flavonoidsand phenol contents in the ethyl acetate fraction were determined by colorimetric and Folin–Ciocalteu methods, respectively. Chemical constituents were isolated from the ethyl acetate fraction and repeatedly purified using silica gel, Sephadex LH-20 column chromatography, and HPLC, respectively. The chemical structures isolated were identified by spectral analysis and chemical evidence. Results Ethyl acetate partition from liquid-liquid extraction exhibited the highest anti-oxidative activity with an IC50 value of 4.94 μg/mL, close to that of the standard(vitamin C, VC, 4.23 μg/mL). The extract was proved to contain total flavonoids and phenol contents with values of(39.0 ± 1.6) and(29.27 ± 1.46) mg/g, respectively. Six compounds were isolated and identified as kaempferol-3,7-dimethyl ether(1), verbascoside(2), apigenin(3), umuhengerin(4), ladanetin(5), and scutellarein-7-O-β-D-apiofuranoside(6).Conclusion The ethyl acetate extract from the leaves of L. trifolia possesses the potent anti-oxidative and free radical scavenging activities which are directly proportional to the concentration of phenolic contents. The anti-oxidative activity of the extract from the leaves of L. trifolia is due to its proton donating ability that converts free radicals to more stable products and terminates chain reactions. Compound 1 is isolated from the plants of Lantana Linn. for the first time. The mechanisms may be related to the therapeutic benefits of the certain traditional claims of wild L. trifolia.     

The antioxidant activity of Clitoria ternatea flower petal extracts and eye gel

Extracts of Clitoria ternatea (butterfly pea) flowers are used in Thailand as a component of cosmetics and the chemical composition of the flowers suggest that they may have antioxidant activity. In this study the potential antioxidant activity of C. ternatea extracts and an extract containing eye gel formulation was investigated. Aqueous extracts were shown to have stronger antioxidant activity (as measured by DPPH scavenging activity) than ethanol extracts (IC₅₀ values were 1 mg/mL and 4 mg/mL, respectively). Aqueous extracts incorporated in to an eye gel formulation were also shown to retain this activity, however, it was significantly less than a commercial antiwrinkle cream included for comparison. The total phenolic content was 1.9 mg/g extract as gallic acid equivalents. The data from this study support the use of C. ternatea extracts as antioxidant inclusions in cosmetic products. Copyright © 2009 John Wiley & Sons, Ltd.     

Medicinal and edible lignicolous fungi as natural sources of antioxidative and antibacterial agents

The antioxidant activity of organic extracts of eight fungal species, Ganoderma lucidum, Ganoderma applanatum, Meripilus giganteus, Laetiporus sulphureus, Flammulina velutipes, Coriolus versicolor, Pleurotus ostreatus and Panus tigrinus, was evaluated for free radical (DPPH^· and OH^·) scavenging capacity and an effect on lipid peroxidation, and the antibacterial activity was tested by the agar well diffusion method. The highest DPPH^· scavenging activity was found in the methanol extract of G. applanatum (12.5 μg/mL, 82.80%) and the chloroform extract of G. lucidum (510.2 μg/mL, 69.12%). The same extracts also showed the highest LP inhibition (91.83%, 85.09%) at 500 μg/mL, while the methanol extracts of G. applanatum and L. sulphureus showed the highest scavenging effect on OH^· radicals (68.47%, 57.06%, respectively) at 400 μg/mL. A strong antibacterial activity against Gram‐positive bacteria was also manifested. The antioxidative potencies correlated generally with the total phenol content (0.19–9.98 mg/g). The HPLC determination showed that the majority of analysed species contained gallic and protocatechic acids. Consequently, these fungi are shown to be potential sources of antioxidative and antibacterial agents. Copyright © 2010 John Wiley & Sons, Ltd.     

The Immunosuppressive Effects of Globularia alypum Extracts

Responder lymphocytes were cultured with an equal number of irradiated stimulator lymphocytes from another donor for 6 days in RPMI 1640 (a modified Mc Coh's 5 A Medium). After 48 h incubation with PMA (phorbol 12-myristate), PHA (phytohaematogglutin) and 120 h with MLR (mixed lymphocytes reaction), the cells were labelled with ³H-thymidine. Cells were harvested in a scintillation counter Globularia alypum L. extracts were dissolved in HPLC quality ethanol or water and diluted in RPMI to concentrations ranging from 0.156–10 μg/mL. Extract solutions were added immediately after cell stimulation in the cell walls. Cyclosporin A was used as a control. Both the water and ethanol extracts of Globularia alypum L. demonstrated a dose response effect in all three systems of MLR, PHA and PMA with no statistical difference in water or ethanol extracts. The IC₅₀ were: PHA 1.14 μg/mL, PMA 1.05 μg/mL and MLR 2.06 μg/mL. The PHA and MLR IC₅₀ are approximately double the IC₅₀ for cyclosporin A (0.5 μg/mL). The effects of Glubularia alypum L. in PMA stimulated lymphocytes suggests it may suppress T cell function through a pathway that cyclosporin A does not effect.     

Comparative biological study of roots,stems, leaves,and seeds of Angelica shikokiana Makino

Ethnopharmacological relevance

Angelica shikokiana has been used as a health food for its anticancer, anti-inflammatory, antibacterial, antiallergic, and blood vessel dilating effects in Japan. It can also be used to prevent and treat hepatitis, diabetes, hyperlipidemia, and arteriosclerosis.

Aim of the study

The present study was designed to compare the biological activities such as melanin synthesis inhibitory, anti-allergy, anti-lipase, anti-bacterial, anti-oxidant, and neuroprotective activities of different parts of the plant that may justify the use of this plant in folk medicine.

Material and methods

The roots, stems, leaves and, seeds of Angelica shikokiana were separately extracted with water and ethanol. Each extract was examined for melanin synthesis inhibitory and anti-allergy activity on B16-melanoma and RBL-2H3 cells using IgE and A23187 as a stimulant for β-hexosaminidase release, respectively. We also evaluated the inhibition of two enzymes, lipase and acetylcholine esterase, and of the bacterial growth of two species, Escherichia coli and Staphylococcus aureaus. The anti-oxidant activity was determined using oxygen radical anti-oxidant capacity, ORAC assay and its relation to the phenolic content was estimated using the Folin–Ciocalteu method. Besides, the protective effect of the extracts against H₂O₂-induced oxidative stress in mouse neuroblastoma, Neuro-2A cells was investigated.

Results

The most active extract exhibiting melanin synthesis inhibition (63%) and at the same time with low cytotoxicity (15%) was the ethanol extract of roots at 20 µg/ml, followed by the ethanol extract of stems (57% inhibition, 5% cytotoxicity). On the other hand, the highest inhibitions of β-hexosaminidase release were recorded for the ethanol extract of leaves with IC₅₀ value of 6.89 µg/ml followed by the water extract of the seeds and leaves with IC₅₀ value of 78.32 and 88.44 µg/ml, respectively. For anti-lipase assay, ethanol extracts of the stems and roots showed the strongest inhibition with IC₅₀ values of 204.06 and 216.24 µg/ml, respectively. None of the examined extracts showed any activity against Escherichia coli. while the ethanol extract of the roots and stems showed moderate inhibition for Staphylococcus aureus with minimum inhibitory concentration of 400 µg/ml. Ethanol extract of the roots showed only 30% inhibition of acetylcholine esterase enzyme. The results of anti-oxidant, phenolic content and protective effect against H₂O₂-induced cytotoxicity assays showed highly correlated data. Ethanol extract of the stems (ORAC value of 1.08 µmol Trolox/ mg and phenolic content 44.25 μg GAE/mg) increased the cell viability of H₂O₂-treated Neuro-2A cells by 28%.     

Protective effects of neohesperidin and poncirin isolated from the fruits of Poncirus trifoliata on potential gastric disease

The effects of Poncirus trifoliata (P. trifoliata) (Ponciri Fructus, PF) extract and its constituents such as neohesperidin and poncirin on gastritis in rats and human gastric cancer cells were investigated. The PF 70% ethanol extracts (1 g) showed approximately 11.38% of acid‐neutralizing capacities and cytotoxicity (IC₅₀ = 85.39 µg/mL) against human AGS gastric cancer cells. In addition, neohesperidin exhibited antioxidant activity (IC₅₀ = 22.31 µg/mL) in the 1,1‐diphenyl‐2‐picryldydrazyl (DPPH) radical‐scavenging assay. Neohesperidin (50 mg/kg) and poncirin (100 mg/kg) significantly inhibited 55.0% and 60.0% of HCl/ethanol‐induced gastric lesions, respectively, and increased the mucus content. In pylorus ligated rats, neohesperidin (50 mg/kg) significantly decreased the volume of gastric secretion and gastric acid output, and increased the pH. From these results, it could be suggested that neohesperidin and poncirin isolated from PF may be useful for the treatment and/or protection of gastritis. Copyright © 2009 John Wiley & Sons, Ltd.     

丹参茎叶提取物抗氧化活性物质基础与量效关系研究

目的以7月份和12月份采收丹参茎叶的水提物和醇提物为研究对象,评价丹参茎叶提取物的抗氧化效应,并探讨丹参茎叶提取物抗氧化活性的物质基础。方法采用超高效液相-三重四级杆质谱联用技术(UPLC-TQ/MS)对各提取物中化学成分进行定性定量分析,明确丹参茎叶提取物中主要丹酚酸类化合物(丹参素、咖啡酸、迷迭香酸和丹酚酸B),基于1,1-二苯基-2-三硝基苦肼(DPPH)、2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐(ABTS)自由基清除法和铁还原/抗氧化能力(FRAP)法对丹参茎叶提取物进行抗氧化活性评价,同时以市售丹参(根及根茎)样品作对照。结果 7月份采收丹参茎叶水提物(SY-7)抗氧化活性最强,且总酚酸的量最高(75.663 mg/g),其次为7月份采收丹参茎叶醇提物(CY-7),市售丹参提取物抗氧化活性及总酚酸的量均低于7月份采收丹参茎叶提取物。丹酚酸单体化合物丹参素、咖啡酸、迷迭香酸和丹酚酸B均具有明显抗氧化、清除自由基能力,且表现出明显的量效关系。结论丹参茎叶水提物和醇提物具有较强的体外抗氧化活性,且含有丰富的丹酚酸类化合物,其中含有的丹参素、咖啡酸、迷迭香酸和丹酚酸B具有明显抗氧化活性。     

Tanzanian medicinal plants used traditionally for the treatment of malaria: In vivo antimalarial and in vitro cytotoxic activities

Seventeen fractions of extracts obtained from 11 Tanzanian medicinal plants, which had previously been shown to possess a high antimalarial activity in vitro were submitted to the 4-day suppressive test in Plasmodium berghei-infected mice, and were investigated for cytotoxic activity in human carcinoma cell lines in vitro. Several fractions administered orally to the mice (500 mg/kg body weight/day) produced a significant reduction of parasitaemia. The most effective plant fractions investigated were those of the root and stem bark of Maytenus senegalensis (90% and 63% suppression of parasitaemia, respectively) and of the roots of Cissampelos mucronata (59% suppression). Highest cytotoxic activities were found with all fractions of Maytenus senegalensis (IC₅₀ 1 μg/mL) and with the PE fraction of the roots of Salacia madagascariensis (median IC₅₀=1.2 μg/mL for HT 29 and 2.3 μg/mL for KB).     

Effect of Honghua (Flos Carthami) on nitric oxide production in RAW 264.7 cells and α-glucosidase activity

Objective

To study the effects of extracts from Honghua (Flos Carthami) on lipopolysaccharide induced nitric oxide (NO) production in RAW 264.7 cells and the influence of the extracts on yeast α-glucosidase activity. The total flavonoid content of the extracts was also determined.

Methods

Cytotoxicity of the extracts to RAW 264.7 cells was evaluated by the ATPlite™ method. Inhibitory effects of the extracts on NO production were evaluated by Griess assay. Curcumin was used as a positive control. Screening of extracts for potential α-glucosidase inhibitors was done by a fluorometric assay. The assay was based on the hydrolysis of 4-methylumbelliferyl-a-D-glucopyranoside to form the fluorescent product, 4-methylumbellifer-one. Acarbose was used as a positive control. The total flavonoid content was tested using kaempferol as the standard.

Results

There were significant inhibitory effects on NO production when the extracts were 25-100 μg/mL (P<0.05) and curcumin was 2-4 μg/mL (P< 0.001). The extracts showed an inhibitory effect on α-glucosidase activity at the concentrations of 15.6-125 μg/mL with a half maximal (50%) inhibitory concentration (IC50) of (32.8 ± 5.7) μg/mL, compared with the IC₅₀ of acarbose at (1.8±0.4) μg/mL. There was a significant difference between the two IC₅₀ values (P<0.001). The total content of flavonoids per gram of dried herb was 1.14 mg.

Conclusion

Honghua (Flos Carthami) showed inhibitory effects on NO production in activated RAW 264.7 macrophage cells and an inhibitory effect on yeast α-glucosidase. There might be a relationship between these pharmacological effects and its flavonoid content.     

Compounds with tyrosinase inhibition, elastase inhibition and DPPH radical scavenging activities from the branches of Distylium racemosum Sieb. et Zucc

Twenty compounds were isolated from the ethanol extract of Distylium racemosum branches and their inhibitory activities on tyrosinase, elastase and free radicals evaluated. The isolated compounds were identified as dibenzofurans (1–4), abscisic acid (5), 6′‐O‐galloylsalidroside (6), catechin derivatives (7–11), gallic acid derivatives (12–14), tyrosol (15), flavonoids (16–18), lupeol (19) and 1,2,3,6‐tetragalloylglucose (20). For study of tyrosinase inhibition activities, when compared with arbutin (IC₅₀ 48.8 μg/mL), four compounds (8, 11, 13, 17) showed higher activities, with IC₅₀ values of 4.8, 30.2, 40.5 and 37.7 μg/mL, respectively. For the elastase inhibition test, dibenzofuran 1 showed greater activity than the positive control, oleanolic acid (IC₅₀ 9.7 μg/mL), with an IC₅₀ of 7.7 μg/mL. In the studies on DPPH radical scavenging activities, five compounds (11, 12, 13, 14, 15) showed higher activities than ascorbic acid (IC₅₀ 5.0 μg/mL), with IC₅₀ values of 4.6, 3.9, 2.9, 3.8 and 4.7 μg/mL, respectively. Copyright © 2011 John Wiley & Sons, Ltd.     

Effect of different plant growth regulators on callus and adventitious shoots induction, polysaccharides accumulation and antioxidant activity of Rhodiola dumulosa

ObjectiveAs a medicinal plant, the resource of Rhodiola dumulosa is deficient along with the large collection. For the protection and utilization of R. dumulosa, the influence of plant growth regulators (PGRs) on callus induction and adventitious shoots differentiation, polysaccharide production and the antioxidant activity were tested.MethodsInternodes of R. dumulosa were used as explants and cultured on MS medium plus different plant growth regulators (PGRs). The anti-oxidative activities of polysaccharides were evaluated using radical scavenging assays.ResultsBy response surface plot, 0.85 mg/L N6-benzyladenine (BA), 0.34 mg/L naphthaleneacetic acid (NAA) and 0.33 mg/L 2,4-dicholorophenoxyacetic acid (2,4-D) were the optimal factors for callus induction (90.03%) from internodes explants on MS medium. The fresh weight of green callus increased 47.26 fold, when callus was inoculated on MS + thidiazuron (TDZ) 0.5 mg/L + NAA 2.0 mg/L. Adventitious buds regenerated from callus on the media of MS were fortified with BA 1.0 mg/L plus NAA 0.5 mg/L, and the induction rate was 40.00%. MS plus indole-3-butyric acid (IBA) 1.0 mg/L produced the highest rooting rate with 10 to 15 roots in a length of 2–3 cm per shoot. The content of total polysaccharides in callus developed on MS + TDZ 0.5 mg/L + NAA 2.0 mg/L and MS + BA 1.0 mg/L + NAA 0.5 mg/L was as high as 1.72%−2.15%. At the dose of 0.5 mg/mL polysaccharides extracted from different callus induced on MS + NAA 2.0 mg/L + TDZ 0.5 mg/L or MS + BA 1.0 mg/L + NAA 0.5 mg/L or MS + BA 0.5 mg/L + 2,4-D 0.5 mg/L, the ABTS radical eliminating percentages were 82.78%, 80.18% and 68.59%, respectively, much higher than that of wild plant.ConclusionA rapid micropropagation system for R. dumulosa has been developed. The combination of TDZ and NAA or BA and NAA can increase the yield of the total polysaccharides. The polysaccharides isolated from callus and whole wild plants had stronger free radicals scavenging activities, indicating that polysaccharides from R. dumulosa are the potential pharmaceutical supplements.     

Effects of Sweet Bee Venom on the Central Nervous System in Rats: Use of a Functional Observational Battery

Objectives: Reactive oxygen species (ROS) are continuously produced at a high rate as a by-product of aerobic metabolism. Because of tissue damage by free radicals, ROS such as hydrogen peroxide (H₂O₂) and nitric oxide (NO) increase with age. Several lines of evidence show that ROS appear to cause the development of various aging-related diseases, such as cancer, arthritis, and cardiovascular disease. In this study, we investigated the pharmacological effects of red ginseng to determine the feasibility of using it as a pharmacopuncture drug source or health food.Methods: For our aims, we investigated the biological activities of red ginseng ethanol extracts (RGEE) by measuring the total polyphenol contents, the total flavonoid contents, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, the 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS) radical scavenging activity, and the cell viabilities of MCF 10A and SK-MEL-2 in vitro with the dimethyl thiazolyl diphenyl tetrazolium salt (MTT) assay method.Results: The total polyphenol content of RGEE was 3.06 ± 0.11mg/g in 10 mg/ml, and the total flavonoid content of RGEE was 1.35 ± 0.01mg/g in the same concentration. The ABTS radical scavenging activity was about 80%, and that of the DPPH activity was 65% in 50 mg/ml of RGEE. The cell viability of the SKMEL-2 skin cancer cell line was decreased and that of the MCF 10A skin normal cell line was increased.Conclusions: We conclude that RGEE may be useful as a potential functional food or pharmacopuncture drug source for the treatment of diseases induced by oxidant stress.Key Words: red ginseng; red ginseng ethanol extracts; antioxidant activity; skin cell viability     

Antioxidant activity of Osbeckia aspera

Plants of the Osbeckia family have been shown to possess hepatoprotective properties, which could be due to the presence of antioxidant compounds. The plant extract was shown to inhibit significantly in a dose-dependent manner, the activities of the DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical (EC₅₀ of 27.5 μg/mL), xanthine oxidase (EC₅₀ of 1.16 mg/mL) and demonstrate a scavenging effect on hydroxyl radical mediated damage to deoxyribose (EC₅₀ of 140 μg/mL). The plant extract possessed some prooxidant activity from the effect on bleomycin-induced DNA damage, but this was less than that shown by comparable concentrations of (+)-catechin or silymarin. © 1998 John Wiley & Sons, Ltd.     

Quality Evaluation of Astragali Radix based on DPPH Radical Scavenging Activity and Chemical Analysis

Objective To assess the quality of Astragali Radix from different areas based on the biological evaluation and chemical analysis. Methods The bioassay method of 1,1-diphenyl-2-picryl-hydrazyl(DPPH) radical scavenging activity for Astragali Radix was established. The parameters of DPPH assay including sample extraction time, reaction time, repeatability, and stability were detected. Furthermore, a method of HPLC-MS was developed to simultaneously determine calycosin-7-O-glucoside, ononin, formononetin, and astragaloside IV in Astragali Radix samples. And the total flavonoids and total saponins were detected by spectrophotometry. The relationship between DPPH evaluation and chemical analysis was studied by Pearson correlation analysis. Results Twelvebatches of Astragali Radix from different origins showed a wide range of DPPH radical scavenging activities(IC50 = 1.395-9.894 μg/mL). Based on DPPH assay, Sample 10 derived from Inner Mongolia Autonomous Region(IC50 = 1.395 μg/mL) showed the best quality of all samples. Chemical analysis showed that different compounds selected as indices would cause different results for quality evaluation. Pearson correlation analysis revealed that the contents of total flavonoids(P = 0.032), calycosin-7-glucoside(P =0.035), and astragaloside IV(P = 0.010) were positively correlated with DPPH radical scavenging activity. Conclusion Except for chemical analysis, DPPH radical scavenging activity can be used as a good alternative to assess and control the quality of Astragali Radix.     

Inhibitory properties of selected South African medicinal plants against Mycobacterium tuberculosis

Ethnopharmacological relevance

Tuberculosis (TB), caused by Mycobacterium tuberculosis (MTB) is the most commonly notified disease and the fifth largest cause of mortality. One in 10 cases is resistant to treatment in some areas. Several plants are used locally to treat TB-related disease.

Aims of the study

The aim was to screen selected South African medicinal plants used to treat TB and related symptoms by traditional healers for antimycobacterial activity.

Materials and methods

Ethnobotanical information on these plants was obtained. Crude acetone, methanol, hexane and ethanol extracts of 21 selected medicinal plants obtained in Venda, South Africa were screened for their ability to inhibit MTB H₃₇Ra and a clinical strain resistant to first-line drugs and one second-line drug using tetrazolium microplate assay to determine the minimum inhibitory concentration (MIC). Results were analyzed using Microsoft Excel 2007 and One way ANOVA; p < 0.05 was considered for statistical significance.

Results

Few acetone extracts were active against MTB with MIC under 100 μg/mL. Four plants showed lower MIC values; Berchemia discolor Klotzsch Hemsl 12, 5 μg/mL on H₃₇Ra and 10.5 μg/mL on the clinical isolate, Bridelia micrantha Hochst. Baill (25 μg/mL), Warbugia salutaris Bertol. F Chiov (25 μg/mL), and Terminalia sericea Burch ex D. F (25 μg/mL) on both H₃₇Ra and clinical isolate. However, the roots of Ximenia caffra Sond. Var. caffra, barks of Sclerocarya birrea (A Rich) Hochst, Asclepias fruticosa L, tubers of Allium sativum L, leaves of Carica papaya L, Solanum panduriforme E. Mey C, and roots of Securidaca longepedunculata Fresen gave MIC greater than 100 μg/mL.

Conclusion

The acetone extracts of Berchemiadiscolor, Bridelia micrantha, Terminalia sericea and Warbugia salutaris could be important sources of mycobactericidal compounds against multidrug-resistant MTB.     

一种白蛋白纳米粒的制备与评价

 目的研究白蛋白纳米粒的去溶剂化法制备工艺。方法采用乙醇作为非溶剂,考察了白蛋白质量浓度和pH值、非溶剂(乙醇)体积和加入速度、交联剂体积等对纳米粒产率、粒径以及游离氨基含量的影响。结果将白蛋白100 mg溶于碳酸盐缓冲液(pH9)10 mL中,搅拌下按1.0 mL·min^-1的速度滴加乙醇60 mL,加入0.025 kg·L^-1戊二醛溶液50μL,25℃固化12h,减压浓缩除去乙醇,得白蛋白纳米粒胶体。结论确定了去溶剂化-交联法制备白蛋白纳米粒的优化工艺。     

Cytotoxic Activities of Colombian Plant Extracts on Chinese Hamster Lung Fibroblasts

Fifty-one crude extracts from 31 Colombian plants used in traditional medicine have been screened for cytotoxicity in a MTT assay with V79 cells. Eleven extracts (21%) were active, showing a survival percentage below 20% with respect to the controls. The most active were ethanol and dichloromethane extracts from Acnistus arborescens leaves. The IC₅₀ values obtained (6 and 11 μg/mL) encourage a more in depth investigation.     

Antimicrobial assays of three native British plants used in Anglo-Saxon medicine for wound healing formulations in 10th century England

Ethnopharmacological relevance

Three important Anglo-Saxon medical texts from the 10th century contain herbal formulations for over 250 plant species, many of which have yet to be evaluated for their phytochemical and/or pharmacological properties. In this study, three native British plants were selected to determine antimicrobial activity relevant to treating bacterial infections and wounds.

Materials and methods

Several preparations of Agrimonia eupatoria L., Arctium minus (Hill) Bernh. and Potentilla reptans L. were screened for antimicrobial activity against selected Gram-positive and Gram-negative bacteria of relevance in wounds using a 96 well plate microdilution method (200, 40 and 8 μg/mL). Minimum inhibitory concentration (MIC) values were determined for the most potent extracts from 2 to 0.004 mg/mL and HPLC chromatograms examined by multivariate analysis. Principle components analysis (PCA) was used to identify chemical differences between antimicrobial activity of the crude extracts.

Results

The HPLC–PCA score plots attributed HPLC peaks to the antimicrobial activity with all three plants inhibiting growth of Gram-positive Staphylococcus aureus by >50% in four or more extracts. The first two principal components (PC) represented 87% of the dataset variance. The P. reptans 75% ethanol root extract exhibited the greatest range of activity with MIC₅₀ at 31.25 μg/mL to a total MIC that was also the minimum bactericidal concentration (MBC) at 1 mg/mL. Additionally, the root of P. reptans, inhibited growth of Gram-negative bacteria with the 75% ethanol extract having a MIC₅₀ at 1 mg/mL against Pseudomonas aeruginosa and the decoction a MIC₅₀ at 3.9 μg/mL against Escherichia coli.

Conclusions

The results indicate a moderate antimicrobial activity against common wound pathogens for P. reptans suggesting it may well have been effective for treating wound and bacterial infections. Anglo-Saxon literary heritage may provide a credible basis for researching new antimicrobial formulations. Our approach encompassing advanced analytical technologies and chemometric models paves the way for systematic investigation of Anglo-Saxon medical literature for further therapeutic indications to uncover knowledge of native British plants, some of which are currently lost to modern Western herbal medicine.     

艾纳香不同部位提取物的抗氧化活性及其对酪氨酸酶的抑制作用

目的:考察艾纳香不同部位提取物的抗氧化活性及其对酪氨酸酶的抑制作用,筛选具有抗氧化活性及美白作用的有效部位。方法:采用水,50%乙醇及95%乙醇3种不同极性溶剂分别回流提取艾纳香的功能叶、嫩叶、嫩茎;运用DPPH,ABTS,FRAP法及酪氨酸酶抑制活性试验分别比较各部分提取物的相关活性。结果:艾纳香功能叶、嫩叶、嫩茎的95%乙醇提取物DPPH自由基清除率大于其他溶剂提取物,依次为95.38%,91.32%,92.49%;ABTS,FRAP法及酪氨酸酶抑制试验结果显示艾纳香功能叶和嫩叶的50%乙醇和95%乙醇提取物均具有较好的活性,当各提取物质量浓度为1 500 mg·L-1时,艾纳香功能叶的水,50%乙醇和95%乙醇提取物对ABTS自由基的清除率分别为26.54%,82.48%,67.46%,嫩叶的3种提取物分别为34.15%,95.39%,59.59%,嫩茎的3种提取物分别为52.05%,39.35%,38.77%。功能叶的水,50%乙醇及95%乙醇提取物对酪氨酸酶的抑制率分别为24.24%,32.79%,37.97%;嫩叶不同提取物的抑制率分别为27.12%,36.53%,34.19%,嫩茎的则依次为31.36%,26.22%,24.00%。结论:艾纳香提取物具有较好的抗氧化活性和酪氨酸酶抑制作用,其中功能叶和嫩叶为其主要活性部位。     

Antioxidant activity of yellow dock (Rumex crispus L., Polygonaceae) fruit extract

The methanol extract of ripe Rumex crispus L. fruits was evaluated for its antioxidant potential by assays for ferric‐reducing antioxidant power (FRAP), DPPH‐free radical scavenging activity (DPPH) and the influence on lipid peroxidation in liposomes (LP). Considerable activity was observed in all test systems (FRAP: 9.9 mmol Fe²⁺/g; DPPH IC₅₀: 3.7 μg/mL; LP IC₅₀: 4.9 μg/mL), comparable to that of BHT (FRAP: 8.0 μg/mL; DPPH IC₅₀: 19.4 μg/mL; LP IC₅₀: 3.5 μg/mL), but lower than the activity of ascorbic acid, rutin and quercetin, used as positive control substances. The in vivo effects were evaluated in several hepatic antioxidant systems (activities of LPx, GSH‐Px, Px, CAT and XOD, as well as GSH content), after treatment with the studied yellow dock extract in different doses, or in combination with carbon tetrachloride (CCl₄). Pretreatment with the R. crispus extract inhibited CCl₄‐induced oxidative stress by decreasing LPx and increasing GSH content in a dose dependent manner, bringing the levels of antioxidant enzymes to near control values. Copyright © 2010 John Wiley & Sons, Ltd.