Antioxidant Activity of Chinese Medicinal Herbs

Abstract

Sequential extraction with petroleum ether, chloroform–ethyl acetate, methanol, and water was carried out on 40 commonly used Chinese medicinal herbs. The antioxidant power of different fraction extracts was measured with both the DPPH assay and the FRAP assay. Ascorbic acid and butylated hydroxytoluene were used as two reference antioxidants. The total phenolic content of the extracts was measured by Folin-Ciocalteu method. The fraction extracts showed different antioxidant activity in the two assays; however, there was a significant positive correlation between the DPPH assay and the FRAP assay. Methanol fraction extracts generally demonstrated stronger antioxidant power and higher total phenolic content than did the others. The results suggest that Radix Sanguisorbae, Cortex cinnamomi, Herba taxilli, Semen arecae, and L., Cinnamomum cassia Presl ., Taxillus sutchuenensis (Lecomte) Danser, Areca catechu Linn. and Scutellaria baicalensis Georgi contain relatively high values in antioxidant power and/or high total phenolic content. This study is the first comprehensive antioxidant activity evaluation among Chinese medicinal herbs. It demonstrates that most Chinese medicinal herbs are also useful in preventing various degenerative diseases.     

Polyphenolic Contents and Biological Activities of Rumex ecklonianus.

Abstract

Rumex ecklonianus. Meissner (Polygonaceae) is a wild South African herb whose leaves are edible when young. It is mildly purgative and is used in the treatment of chlorosis and anemia. The polyphenolic content and antioxidant and antibacterial activity of the acetone, methanol, and water extracts were determined in this study. The concentrations of the different classes of phenolic compounds were higher in the acetone and methanol extracts when compared with the water extracts; this also correlates highly with the total phenolic content. Antioxidant activities of acetone and methanol extracts as assessed by three established in vitro. methods, namely, 2,2-azinobis.-(3-ethyl benzothiazoline-6-sulfonic acid) (ABTS), 1,1-diphenyl-2-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP) methods were comparable with that of butylated hydroxyl toluene. The extracts showed significant activity against both Gram-positive and Gram-negative bacteria. The strongest antibacterial activity was found in the acetone extract, whose activity was pronounced on 7 of the 10 bacterial strains used, with a MIC value of 2.0 mg/mL. None of the extracts, however, inhibited Staphylococcus epidermidis. or Salmonella pooni.. The data obtained in this study suggest that R. ecklonianus. may be a good candidate for functional foods as well as pharmaceutical plant-based products. This is the first report on the biological activity of R. ecklonianus..     

Cytogenetic Effects Of Aqueous Extracts Of The Medicinal Plant Paico (Chenopodium Multifidum L.)

The cytogenetic effects of aqueous extracts of Chenopodium multifidum L. (Paico) were determined by addition of the extracts and fractions to human lymphocyte cultures. Toxicity was evaluated by analysis of chromosomal aberrations (CA), sister chromatid exchange (SCE), mitotic (MI) and replication (RI) indexes. The results showed an increase in CA frequency in cultures exposed to infusion decoction, no modification in the CPK values either in the decoction or in the infusion, and a decrease in the MI of lymphocyte cultures exposed to the decoction. These results suggested genotoxic effects of “Paico” aqueous extracts.     

Antinociceptive and antioxidant potential of the crude ethanol extract of the leaves of Ageratum conyzoides grown in Bangladesh

Abstract

Context: Ageratum conyzoides Linn. (Asteraceae) is an annual herbaceous plant with a long history of traditional medicinal and agricultural uses; it is usually grown in the northeast part of Bangladesh.

Objective: The ethanol extract of the plant leaves was evaluated for preliminary phytochemical screening with its antinociceptive and antioxidant activities.

Materials and methods: The preliminary phytochemical analysis was performed on the basis of standard procedures. The analgesic activity of the extract was investigated using the acetic acid-induced writhing method in mice. Five complementary tests such as DPPH free radical scavenging, nitric oxide (NO) scavenging, reducing power, Fe⁺⁺ ion chelating ability and total phenolic content were used for determining antioxidant activities.

Results: The results of preliminary phytochemical analysis showed the presence of alkaloids, reducing sugars, saponins, gums, steroids, tannins and flavonoids. The extract possessed a significant dose-dependent DPPH free radical scavenging activity with an IC₅₀ value of 18.91?μg/ml compared to ascorbic acid (IC₅₀: 2.937?μg/ml) and butylated hydroxyanisole (IC₅₀: 5.10?μg/ml). The IC₅₀ value of the extract for NO scavenging (41.81?μg/ml) was also found to be significant compared to the IC₅₀ value of ascorbic acid (37.93?μg/ml). Moreover, the extract showed reducing power activity and Fe⁺⁺ ion chelating ability. The total phenolic amount was also calculated as quite high (378.37?mg/g of gallic acid equivalents) in the crude ethanol extract.

Discussion and conclusion: Therefore, the obtained results tend to suggest the antinociceptive and antioxidant activities of the ethanol extract of the plant leaves and justify its use in folkloric remedies.     

Iridoid content and biological activities of Veronica cuneifolia subsp. cuneifolia and V. cymbalaria

Context: The genus Veronica L. (Plantaginaceae) is represented by 79 species, 26 of which are endemic in Turkey. Some Veronica species are used for the treatment of different inflammatory diseases and cancer in traditional medicine. In addition, chemotaxonomy of the genus is important for the reclassification of the family Plantaginaceae after different phylogenetic studies.

Objective: Veronica cuneifolia subsp. cuneifolia D. Don and V. cymbalaria Bodard were studied from the view point of iridoid glucosides which are known as chemotaxonomical markers for this genus. Radical scavenging and cytotoxic activities of the extracts were also determined in this study.

Material and methods: Major compounds, isolated from iridoid fractions of V. cuneifolia subsp. cuneifolia were used as the standard compounds for HPLC after determination of their structures, and investigated for their presence in iridoid fractions of V. cymbalaria. Additionally, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and SO radical scavenging and cytotoxic activities against three cancer and a noncancerous cell lines of both extract were also tested using the MTT method.

Results: While aucubin, catalpol, verproside, amphicoside, verminoside, and veronicoside were obtained from V. cuneifolia subsp. cuneifolia, two more iridoid glucosides, 6-O-veratroylcatalposide and 6-O-isovanilloylcatalpol, were isolated from V. cymbalaria. Comparing both species, V. cuneifolia subsp. cuneifolia showed stronger radical scavenging and cytotoxic activities than V. cymbalaria.

Discussion: Our results demonstrated that the iridoid contents of both species were very close to each other confirming to the chemotaxonomic studies on Veronica species and their different bioactivity range make the plants interesting from the view point of natural drug discovery research.     

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.     

Antimicrobial Activity of Neotropical Wood and Bark Extracts

A total of 203 wood and bark extracts obtained from a Neotropical lowland rainforest in French Guiana were tested for antimicrobial activity against a panel of four human pathogens. Inhibitory activity against Staphylococcus aureus was regularly observed. Significant growth inhibition against Enterococcus faecilis was found in species belonging to the plant genus Sloanea (Elaeocarpaceae) and various Sapotaceae. The plant genera Eschweilera, Gustavia and Couratari (Lecythidaceae) showed notable growth inhibitory activity against both Escherichia coli and Enterococcus faecilis. Fractionation of the active extracts showed that the activities against Gram-positive and Gram-negative bacteria appear to be associated with different compounds. In some cases several replicates were sampled, showing that intraspecific activity levels may vary. The results of the screening experiments are compared to eth nomedicinal information available from northern South America and adjacent areas.     

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.     

Antioxidative activities and the total phenolic contents of tonic Chinese Medicinal Herbs

Chinese medicated diet is an everyday practice in China. In this study, 16 commonly used soup making tonic Chinese medicinal herbs were selected for antioxidative capacities by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and ferric reducing antioxidant power (FRAP), and the total phenolic contents of these herbal extracts were measured by the Folin-Ciocalteu method. It confirmed that drinking tonic soups could supplement total antioxidants intake. Amongst the tested herbal extracts, extracts of Canarium album Raeusch., Flos caryophylli and Fructus amomi were found to have the highest antioxidative activities in both DPPH and FRAP assays. Their antioxidative activities were comparable to ascorbic acid and butylated hydroxytoluene. Thus, these herbs are safe and inexpensive sources of natural antioxidants. A significant relationship between the antioxidative effects and total phenolic contents were found, indicating phenolic compounds are the major contributor of antioxidative capacities of these herbs. In addition, a strong correlation between DPPH assay and FRAP assay implied that antioxidants in these herbs were capable of scavenging free radicals and reducing oxidants.     

乌梅抗氧化作用的实验考察

目的:研究乌梅提取物抗氧化作用。方法:通过检测还原力和清除DPPH、ABTS和超氧阴离子自由基的能力,分析和评价乌梅提取物的抗氧化活性。结果:乌梅醇提物对DPPH、ABTS自由基的IC50分别为0.500 mg.mL-1及0.253 mg.mL-1;乌梅水提物对DPPH、ABTS自由基的IC50分别0.510 mg.mL-1及0.500 mg.mL-1;乌梅醇提物还原能力大于乌梅水提物,且乌梅醇提物对超氧阴离子自由基的清除作用显著,其清除作用优于乌梅水提物及对照品BHT。结论:乌梅提取物有不同程度的抗氧化活性,其中以醇提物抗氧化作用最强。     

Antifilarial Effect of a Combination of Botanicals from Acacia auriculiformis and Centella asiatica on Canine Dirofilariasis

A mixture (1:1) of the ethanol extracts from the leaves of Centella asiatica and the funicles of Acacia auriculiformis was administered orally to pariah dogs naturally infected with Dirofilaria immitis at 0.04 mg/g body weight/d for 45 days. Two triterpenoid saponins, acaciaside A and B, isolated from the funicles of A. auriculiformis were combined with the leaf ethanol extract from C. asiatica (1:1) and tested at 0.04 mg/g body weight/d for 45 days on microfilaraemic dogs. There was an initial fluctuation in the microfilarial (mf) count in the blood following treatment with the mixture of crude extracts, and then the mf density decreased up to 99%. This suppression lasted for 120 days. When treated with the saponins mixed with the C. asiatica ethanol extract, there was an 86% reduction in mf density 30 days after the last date of treatment, and 68% reduction was maintained 120 days after the treatment.     

胜红蓟内生真菌乙酸乙酯提取物的抗氧化及抑菌活性研究

越来越多证据表明,内生真菌代谢产物具有重要的生物学活性,胜红蓟(Ageratum conyzoides)是菊科一种具有多种药理活性的入侵草本植物.我们从胜红蓟根、茎、叶和花中分离并鉴定内生真菌,并对其乙酸乙酯提取物的体外抗氧化活性(DPPH、ABTS+和FRAP测定)、抑菌活性及黄酮、多酚含量进行测定.结果 显示,从胜...     

Bioefficacy of Mauritian Endemic Medicinal Plants: Assessment of Their Phenolic Contents and Antioxidant Potential

Abstract

The role of free radicals in the etiology and development of a wide range of clinical disorders has continued to fuel the suggestion that phenolic antioxidants can offer a realistic promise to reduce the incidence of a number of pathologies involving oxidative stress. In this study, the total phenol, flavonoid, and proanthocyanidin contents of the Mauritian medicinal plants Crinum mauritianum. Lodd. (Asteraceae), Gaertnera psychotroides. DC (Rubiaceae), Psidia terebinthina. A.J. Scott (Asteraceae), and Tylophora coriacea. Marais. (Monimiaceae) were assessed and contrasted with their antioxidant potential. The antioxidant propensity was evaluated by the ability of the extracts to scavenge hypochlorous acid and hydroxyl radical and the ABTS^{? +} radical including their abilities to inhibit microsomal lipid peroxidation. The endemic plants Badula multiflora. A. DC. (Myrsinaceae), Croton vaughanii. L. (Euphorbiaceae), Erythroxylum macrocarpum. Lam. (Erythroxylaceae), Ochna mauritiana. Lam. (Ochnaceae), Tambourissa cordifolia. Lorence. (Monimiaceae), and Turraea rigida. Vent. (Meliaceae) were similarly investigated. Badula multiflora. and Erythoxylum macrocarpum. showed highest antioxidant activity in the TEAC and FRAP assay. Badula multiflora., Ochna mauritiana., and Gaertnera psychotroides. were very potent scavengers of hypochlorous acid and inhibited microsomal lipid peroxidation induced by 2,2′-azobis.(2-amidinopropane) hydrochloride (AAPH), suggesting that the inhibition was intrinsically linked to peroxyl radical scavenging. The antioxidant activity of Gaertnera psychotroides., Tylophora coriacea., Psidia terebinthina., and Crinum mauritianum. may account for the therapeutic effects of these extracts, in particular, in conditions characterized by inflammation and oxidative mechanisms. While these polyphenolic-rich endemics are good sources of natural prophylactic antioxidants, there is an urgent need for sustainable conservation programs for their protection.     

Phytochemical screening and evaluation of in vitro antioxidant and antimicrobial activities of the indigenous medicinal plant Albizia odoratissima

Context: Albizia odoratissima (L. f.) Benth has been used in Indian folk medicine to treat numerous inflammatory pathologies, such as leprosy, ulcers, burns and asthma.

Objective: To evaluate the antioxidant and antimicrobial properties of A. odoratissima.

Materials and methods: Dried leaves of A. odoratissima were extracted in organic solvents (hexane, chloroform, ethyl acetate, and methanol). The total phenolic content (TPC) and total flavonoid content (TFC) were determined using the Folin-Ciocalteu and aluminum chloride colorimetric methods, respectively. The antioxidant activity was examined using 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydrogen peroxide (H₂O₂), 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS), and ferric reducing antioxidant power (FRAP) assays. The antibacterial activity was examined using minimum inhibitory concentration (MIC) and the minimum bacterial concentration (MBC), determined by broth microdilution method against Gram-negative bacteria (Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, and Proteus vulgaris) and Gram-positive bacterium (Staphylococcus aureus).

Results: The TPC ranged from 4.40?±?1.06 to 1166.66?±?31.85?mg GAE/g of dry weight (DW), and the TFC ranged from 48.35?±?3.62 to 109.74?±?1.84?mg QE/g of DW. The IC₅₀ values of the ethyl acetate extract for DPPH, ABTS, and H₂O₂ were 10.96?±?0.40, 4.35?±?0.07, and 163.82?±?1.52?μg/mL, respectively. Both methanol and ethyl acetate extracts demonstrated effective antibacterial activity with MICs and MBCs values ranging 136–546?μg/mL and 273–1093?μg/mL, respectively, against the tested pathogenic species.

Conclusions: The leaves of A. odoratissima showed potent free radical scavenging property and antimicrobial activity.     

Antioxidant Potential of Gynura procumbens

Abstract

The leaves of Gynura procumbens (Merr.) Compositae, commonly called “sambung nyawa” in Malaysia, are often eaten raw with rice. The methanol extract was prepared from the dried leaves using a Soxhlet apparatus. The methanol extract was then fractionated into chloroform, ethyl acetate, n-butanol, and aqueous fractions using a separating funnel. In the current study, the antioxidant potency of G. procumbens extract and fractions were investigated, employing various established in vitro systems, such as trolox equivalent antioxidant capacity, β -carotene–linoleic acid model system, 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging, reducing power, and xanthine oxidase inhibitory activity. Based on the results obtained, the extract and fractions showed different antioxidant potential. Among the fractions, the ethyl acetate fraction displayed higher antioxidant properties. The contents of the potential antioxidant component of the extract and fractions were also determined using HPTLC densitometric and spectrophotometric (using Folin-Ciocalteu reagent) methods. HPTLC study revealed that the methanol extract and the ethyl acetate and n-butanol fractions contain 0.74% and 2.9%, 7.76% and 12.75%, and 4.52% and 0.33% of kaempferol-3-O-rutinoside and astragalin, respectively. The total phenolic content of the extract and fractions varied from 4.37% to 23.43% of dry weight, expressed as gallic acid equivalents (GAE). With further data analysis, it was found there was a significant correlation (p < 0.05) between the total phenolic content of the sample and its DPPH scavenging activity and reducing power with correlation coefficients (r) of 0.891 and 0.926, respectively. These results suggest that phenolics in these plants provide substantial antioxidant activity.     

Free Radical Scavenging Activity of Linum arboreum.

Abstract

The methanol and water extracts of Linum arboreum.. aerial parts were screened for free radical scavenging activity. The free radical scavenging activity was determined spectrophotometrically on the basis of inhibition of cytochrome c reduction and the ability to bleach the stable radical 2,2-diphenyl-1-picrylhydrazyl (DPPH). The methanol extracts of Linum arboreum. were shown to have potent antioxidant activity.     

盐炙对广西余甘子中黄酮类成分清除DPPH自由基谱效关系的影响

目的:分析盐炙对广西余甘子中黄酮类成分清除DPPH自由基(1,1-二苯基-2-苦肼基)谱效关系的影响.方法:采用高效液相色谱法,建立13批广西不同产地余甘子盐炙前后黄酮类成分的HPLC指纹图谱,结合DPPH自由基体外抗氧化试验,用改进的灰色关联分析法分析整体的指纹图谱与药效之间的关联.结果:确定了20个特征共有峰,清除...     

A comparative evaluation of mutagenic,antimutagenic, radical scavenging and antibacterial activities of essential oils of Pituranthos chloranthus (Coss. et Dur.)

The Salmonella typhimurium/microsome assay is a widely used bacterial genotoxicity assay to test potential carcinogens. The aim of this work was to evaluate the mutagenic and antimutagenic activities with and without the addition of an extrinsic metabolic activation system of essential oils obtained from an aerial part of Pituranthos chloranthus harvested from different stations in Tunisia. The oils showed no mutagenicity when tested with S. typhimurium strains TA98, TA100, and TA1535. On the other hand, we showed that these essential oils reduced significantly Benzo [a] pyrene (B[a] P) and sodium-azide–induced mutagenicity. The scavenging capacity of these essential oils was also estimated by evaluating the inhibition of DPPH radical. Essential oils harvested at Medenine and Gabes in November were more effective in scavenging activity. The essential oils were tested for their antimicrobial properties against five different bacteria, and were found to be weakly active, with MIC and MBC values in the range 0.6–4 and 2.2–5?mg/mL, respectively.     

红树林放线菌Streptomyces sp.CHQ-61产生的胞外多糖结构及自由基清除活性

目的 探究红树林放线菌Streptomyces sp.CHQ-61产生的胞外多糖的结构及自由基清除活性。方法 利用乙醇沉淀法、阴离子交换层析柱和凝胶层析柱对菌株发酵产物中的胞外多糖进行分离纯化,运用核磁共振、气质联用色谱、红外光谱、高效凝胶渗透色谱和柱前衍生高效液相色谱分析鉴定多糖的结构特征,采用DPPH、超氧阴离子和羟基自由基清除率评价胞外多糖的抗氧化活性。结果 从红树林放线菌Streptomyces sp.CHQ-61发酵产物中分离得到多糖XH-1,其分子量为8.9 kDa,丙酮酸含量为4.0 %,主要由半乳糖和氨基葡萄糖组成,糖链主要含有(1→6)Galp,还有少量的(1→3)GlcNp、(1→4,6)Galp、(1→3,6)GlcNp、末端Galp和GlcNp,XH-1具有一定的体外自由基清除活性,其清除DPPH、超氧阴离子和羟基自由基的EC50分别为0.5、0.8和3.0 mg/mL。结论 本文首次报道了红树林根泥放线菌Streptomyces sp.CHQ-61产生的胞外多糖XH-1为1种含有丙酮酸的半乳糖和氨基葡萄糖组成的结构新颖的胞外多糖,其具有较强的体外自由基清除活性。     

Synthesis and In Vitro Antioxidant Activity of New 3-Substituted-2-Oxindole Derivatives

A series of new 1,3-dihydro-3-hydroxy-3-(2-phenyl-2-oxoethyl)-2H-indol-2-ones (1a-g) and 1,3-dihydro-3-(2-phenyl-2-oxoethylidene)-2H-indol-2-ones (2a-g) were synthesised by Knoevenagel condensation of substituted indole-2,3-diones (isatins) with various acetophenones. The synthesised compounds were characterised by their physical data, elemental, IR, ¹H NMR, ¹³C NMR and mass spectral analyses and their in vitro antioxidant activity was determined by 2,2-diphenyl-1-picrylhydrazyl free radical scavenging assay. These compounds showed moderate to good antioxidant activities as compared with the standard, ascorbic acid. The antioxidant potential of 3-hydroxy-3-substituted oxindoles (1a-g) increased in a concentration-dependent manner from 10 to 500 μg/ml with 5-fluoro and 5-methyl analogues showing maximum activity. Of 3-aroyl methylene indol-2-ones (2a-g), majority of compounds with halogen substitution at position 5 of isatin ring exhibited good antioxidant activity within a concentration range of 5-100 μg/ml and the maximum activity was observed at 20 and 25 μg/ml concentrations. Thus, our study provides evidence that some newly synthesised isatin derivatives exhibit substantial antioxidant activity at low concentrations.