Phenolic production and antioxidant properties of some Macedonian medicinal plants

Investigations have been made to study the production of phenolic compounds (total phenolics, flavonoids and phenylpropanoids) and total antioxidant capacity in 27 Macedonian traditional medicinal plants to improve its potential as a source of natural antioxidants. Antioxidant potential of plant extracts was analyzed by five different assays: cupric reducing antioxidant capacity (CUPRAC), phosphomolybdenum method (PM), reducing power (RP), 2,2-diphenyl-1-picrylhydrazyl (DPPH^·) and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS^·+) radical scavenging activity. Origanum vulgare extract consistently exhibited the highest content of phenolic compounds and the strongest antioxidant capacity based on the tests performed, and can be proposed as a promising source of natural antioxidants. Melissa officinalis and Salvia ringens were also identified as valuable sources of antioxidant compounds. A positive linear correlation between antioxidant activity and total phenolics, flavonoids and phenylpropanoids indicates that these compounds are likely to be the main antioxidants contributing to the observed activities of evaluated plants. These findings suggest that the medicinal plants studied in this paper are good sources of bioactive compounds for the food and pharmaceutical industries.     

Phenolic composition and antioxidant activities of two Phlomis species: A correlation study

Two traditional Chinese medicines (Phlomis umbrosa Turcz. and Phlomis megalantha Diels), as well as five pure phenolic compounds (protocatechic, chlorogenic, benzoic, rosmarinic acid, and rutin) have been studied for antioxidant activities in acetone and methanol extracts from leaves. An HPLC method was developed to quantify the amounts of 14 phenolic compounds in the leaf extracts. The antioxidant capacities of the studied species are high. Almost all samples were capable of directly scavenging DPPH and superoxide free radicals, inhibiting linoleic acid oxidation, acting as reducing agents, and reducing plasmid DNA damage induced by hydroxyl radicals. Among different extracts, the acetone extract of P. megalantha exhibited the highest antioxidant activity. The major phenolic compounds identified were protocatechic, chlorogenic, caffeic, rosmarinic acid, and (−)-epicatechin. Antioxidant activities of pure compounds and correlation analysis indicated that protocatechic and rosmarinic acids were the major contributors to the observed antioxidant activities of the investigated Phlomis extracts. To cite this article: Y. Zhang, Z.-z. Wang, C. R. Biologies 332 (2009).     

Antioxidant activity and phenolic compounds of 112 traditional Chinese medicinal plants associated with anticancer

Cancer prevention and treatment using traditional Chinese medicines have attracted increasing interest. This study characterizes antioxidant activity and phenolic compounds of traditional Chinese medicinal plants associated with anticancer, comprising 112 species from 50 plant families. The improved ABTS(*+) method was used to systematically assess the total antioxidant capacity (Trolox equivalent antioxidant capacity, TEAC) of the medicinal extracts. The TEAC values and total phenolic content for methanolic extracts of herbs ranged from 46.7 to 17,323 micromol Trolox equivalent/100 g dry weight (DW), and from 0.22 to 50.3 g of gallic acid equivalent/100 g DW, respectively. A positive, significant linear relationship between antioxidant activity and total phenolic content (all R(2) values>/=0.95) showed that phenolic compounds were the dominant antioxidant components in the tested medicinal herbs. Major types of phenolic compounds from most of the tested herbs were preliminarily identified and analyzed, and mainly included phenolic acids, flavonoids, tannins, coumarins, lignans, quinones, stilbenes, and curcuminoids. These medicinal herbs exhibited far stronger antioxidant activity and contained significantly higher levels of phenolics than common vegetables and fruits. Traditional Chinese medicinal plants associated with anticancer might be potential sources of potent natural antioxidants and beneficial chemopreventive agents.     

In vitro propagation of Caralluma tuberculata and evaluation of antioxidant potential

Present study describes rapid in vitro propagation of Caralluma tuberculata, a traditional medicinal plant, and antioxidant potential of calli and plants extracts. The highest callus induction rate (93.3%) with maximum weight of calli 5.2 g was achieved from shoot tip explants on MS medium supplemented with 9.04 μM 2,4-D and 4.44 μM BA. The maximum shoot induction rate (71.1%) with mean number of shoots 3.66 ± 1.53 and 4.6 cm average shoot length was observed on 13.32 μM BA, 4.52 μM 2,4-D and 2.89 μM GA3 appended in MS medium. The developed shoots were best rooted in the presence of 5.07 μM IAA with 3.0 ± 0.15 roots per plantlet. The plants were successfully acclimatized under in vivo conditions. The plants and calli extracts exhibited good antioxidant activities, however, plant extract activities were more pronounced. The phenolic compounds in plant and calli extracts were 0.16% and 0.057%, respectively. While the flavonoids were 0.092% in plant and 0.039% in calli extract. Total Phenolics, flavonoids; DPPH radical scavenging activity and reducing power potential distributed among different fractions depending upon polarity of the solvent. The highest DPPH scavenging activity and reducing power was exhibited by water fractions; 4.95 mg/mL and 0.729 OD at 10 mg/mL, respectively. The micropropagation protocol can be successfully used for large-scale multiplication and conservation of germplasm of this threatened plant. Furthermore, antioxidant value describes importance of this valuable plant as food and medicine.     

Variation in antioxidant properties and phenolics concentration in different organs of wild growing and greenhouse cultivated Castilleja tenuiflora Benth.

The content of total phenolic compounds and flavonoids was determined in methanol extracts of root, stem, leaves, and inflorescences from wild growing and greenhouse cultivated plants of Castilleja tenuiflora. The antioxidant activity in each extract was evaluated using three in vitro models: scavenging of free radicals with 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS), and reducing power by the phosphomolybdenum assay. Both, antioxidant activity and phytochemicals content were influenced significantly (P < 0.05) by the source of the plant material and the organ. Cultivated plants had the highest content of phenolic compounds (37.95 mg gallic acid equiv. g^?1 dry weight, P < 0.05) and the strongest antioxidant activity. Total phenolic compounds content correlated significantly with the antioxidant activity for all studied plant material and organs (P < 0.05). TLC profile using DPPH as a detection reagent indicated that the phenylethanoids verbascoside and isoverbascoside are the main contributors to the free-radical scavenging of C. tenuiflora. Cultivated plants of C. tenuiflora are an alternative source of natural antioxidants to wild growing plants. The antioxidant properties of C. tenuiflora may be associated with its traditional use to treat conditions consistent with radical-related diseases (e.g. inflammation, tumors).     

Chemical compositions by using LC–MS/MS and GC–MS and antioxidant activities of methanolic extracts from leaf and flower parts of Scabiosa columbaria subsp. columbaria var. columbaria L.

The members of the Scabiosa genus are one of the traditional medicinal plants used in the treatment of many diseases, in particular the treatment of scabies. In this study, it was aimed to determine antioxidant activities and chemical composition of methanolic extracts of leaves and flowers of Scabiosa columbaria subsp. columbaria var. columbaria. The phenolic contents of both parts of the plant were analyzed by LC–MS/MS. A total of 6 phenolic compounds were determined and chlorogenic acid was the major compound in both flower and leaf parts of the plants, with 5936.052 µg/g and 8021.666 µg/g, respectively. 6 different methods were used to determine the antioxidant activity of the plant parts. Both leaf and flower parts of the plant showed high antioxidant activity in all tested methods and the antioxidant activity values of the leaf part were measured higher than those of the flower part for four tests. The methanol extracts of the plant parts was analyzed with GC–MS and number of the essential oil compounds in the leaf and flower parts were determined as 17 and 13, respectively. Linalool compound was also found to be common in both parts of the plant. The major compounds of the essential oils were identified as 4-Octadecenal (30.01%) in the flower and carvone (35.44%) in the leaf. In addition, terpene derivatives was determined as 90.32% of the highest essential oil group in the leaf, while this value was determined as 1.42% in the flower. For the flower, aromatics were determined as the main component group with 21.31%.     

Potential of natural phenolic antioxidant compounds from Bersama abyssinica (Meliathacea) for treatment of chronic diseases

Chronic diseases including cardiovascular, diabetes and cancer persist for a long time in the course of treatment affecting health and are currently the cause of many deaths. In most cases, the treatment of chronic infectious diseases especially Tuberculosis relies on conventional drugs which are currently becoming fruitless due to drug resistance and unpredicted complications in course of treatment. However, herbal medicines have for a long time been used in prevention and treatment of chronic diseases including asthma and heart diseases in Africa. In this study, we extracted metabolites and screened for active compounds with potential free radical scavenging and pharmacological activities from Bersama abyssinica, the plant commonly used in traditional medicine in Tanzania. B. abyssinica root, stembark and leaf were air dried, sequentially extracted in various solvents including petroleum ether, dichloromethane, ethylacetate and methanol to yield extracts and fractions. The extracts and fractions were tested for the presence of several metabolites and antioxidant activity. The analysis of chemical compounds from resultant extracts was done by GC–MS for non-polar factions and LC-MS/MC for moderate polar extracts.High amount of phenolic acid, flavonoids and tannin were identified in ethylacetate fraction compared to ethanol, dichloromethane and petroleum ether. The GC–MS analysis of petroleum ether extract of B. abyssinica stem back yielded twelve (12) compounds with varying composition. The most abundant compounds were 2-Butenoic acid, 3-methyl-, ethyl ester comprising 33.8%, n-Hexadecanoic acid comprising 16.7% and Ethanolpentamethyl- yielded in 16.7%.The LC-MS/MS analysis of Ethyl acetate fractions yielded 20 compounds including; Mangiferin and Isoquercitin were abundant in leaves, stembark and roots. Lastly, ethyl vanillate was identified in both roots and leaves whereas Quercitrin and 7,8-Dimethoxycoumarin were found in stembark and root.These findings indicated that B. abyssinica is rich in phenolic compounds ranging from phenolic acids, flavonoids and coumarin that possess high antioxidant and pharmacological properties potential for treatment of chronic diseases.     

Chemical compositions by using LC–MS/MS and GC–MS and antioxidant activities of methanolic extracts from leaf and flower parts of Scabiosa columbaria subsp. columbaria var. columbaria L.

The members of the Scabiosa genus are one of the traditional medicinal plants used in the treatment of many diseases, in particular the treatment of scabies. In this study, it was aimed to determine antioxidant activities and chemical composition of methanolic extracts of leaves and flowers of Scabiosa columbaria subsp. columbaria var. columbaria. The phenolic contents of both parts of the plant were analyzed by LC–MS/MS. A total of 6 phenolic compounds were determined and chlorogenic acid was the major compound in both flower and leaf parts of the plants, with 5936.052 µg/g and 8021.666 µg/g, respectively. 6 different methods were used to determine the antioxidant activity of the plant parts. Both leaf and flower parts of the plant showed high antioxidant activity in all tested methods and the antioxidant activity values of the leaf part were measured higher than those of the flower part for four tests. The methanol extracts of the plant parts was analyzed with GC–MS and number of the essential oil compounds in the leaf and flower parts were determined as 17 and 13, respectively. Linalool compound was also found to be common in both parts of the plant. The major compounds of the essential oils were identified as 4-Octadecenal (30.01%) in the flower and carvone (35.44%) in the leaf. In addition, terpene derivatives was determined as 90.32% of the highest essential oil group in the leaf, while this value was determined as 1.42% in the flower. For the flower, aromatics were determined as the main component group with 21.31%.     

Characterization of saponins and phenolic compounds: antioxidant activity and inhibitory effects on α-glucosidase in different varieties of colored quinoa (Chenopodium quinoa Willd)

ABSTRACT

This study investigated the contents of saponins and phenolic compounds in relation to their antioxidant activity and α-glucosidase inhibition activity of 7 colored quinoa varieties. The total saponin content was significantly different among 7 varieties and ranged from 7.51 to 12.12 mg OAE/g DW. Darker quinoa had a higher content of phenolic compounds, as well as higher flavonoids and antioxidant activity than that of light varieties. Nine individual phenolic compounds were detected in free and bound form, with gallic acid and ferulic acid representing the major compounds. The free and bound phenolic compounds (gallic acid and ferulic acid in particular) exhibited high linear correlation with their corresponding antioxidant values. In addition, the free phenolic extracts from colored quinoa exhibited higher inhibitory activity against α-glucosidase than the bound phenolic extracts. These findings imply that colored quinoa with abundant bioactive phytochemicals could be an important natural source for preparing functional food.     

Antioxidant,Anti‐inflammatory and Cytotoxic Activities of Polyphenols Extracted from Chroogomphus rutilus

Chroogomphus rutilus is a rare fungal species that grows under pine trees and is now widely used as a functional food and pharmaceutical product. However, the chemical constituents and biological activities of Chroogomphus rutilus have been relatively limited. The present study aimed at determining the total polyphenols and flavonoids contents, biological activities and main phenolic compounds of Chroogomphus rutilus from different geographical origins at the stipe and pileus. The results suggested that Chroogomphus rutilus polyphenol extracts revealed a higher antioxidant, anti‐inflammatory, and cytotoxic activities, and there were significant differences between samples from different locations and regions. Correlation analysis showed that the contents of total polyphenols and flavonoids were significantly correlated with antioxidant and anti‐inflammatory activities. However, only the content of total flavonoids was significantly correlated with cytotoxicity, which means that the cytotoxicity of Chroogomphus rutilus polyphenol extracts may be regulated by flavonoids or other compounds. HPLC‐DAD analysis revealed that the main phenolic compound was protocatechuic acid, followed by baicalin, p‐hydroxyphenylacetic acid and p‐hydroxybenzoic acid, but comparing with the pileus extracts, the stipe extracts can be considered as a higher concentration of phenolic compounds. Therefore, antioxidant, anti‐inflammatory and cytotoxic activities of Chroogomphus rutilus polyphenol extracts could be due to the identified compounds. This study investigated a deep knowledge about the constituents and activities of Chroogomphus rutilus and provided the reference for its application in food and pharmaceutical.     

Improving antioxidant activity in transgenic <Emphasis Type="Italic">Codonopsis lanceolata</Emphasis> plants via overexpression of the γ-tocopherol methyltransferase (γ-<Emphasis Type="Italic">tmt)</Emphasis> gene

Codonopsis lanceolata Trautv (Companulaceae) is a folk medicine in Korea. To shift the content of tocopherol and enhance its antioxidant properties, we overexpressed the γ-tocopherol methyltransferase (γ-tmt) gene in C. lanceolata. The antioxidant activity of methanolic crude extracts of the transgenic plants was compared to that of control plants using the 1,1-diphenyl-2-picrylhydrazyl radical scavenging method, with α-tocopherol and butylated hydroxy toluene as standard antioxidants. The antioxidant activity of the leaf and root extracts of transgenic plants was higher (IC ₅₀ 12–17.33 and 408–524 μg/ml, respectively) than that of control plant leaf and root extracts (18 and 529 μg/ml, respectively). High-performance liquid chromatography analysis of phenolic compounds confirmed an increase in the levels of 12 major phenolic acids and flavonoids in the leaf and root extracts of transgenic plants compared to control plants. We also found that the rate of photosynthesis was 48% higher in transgenic plants than in control plants. Based on these results, we suggest that increases in the α-tocopherol level in transgenic C. lanceolata plants may result in increases in the photosynthetic performance and antioxidant metabolism of these plants.     

Investigation of Bolivian plant extracts for their radical scavenging activity and antioxidant activity

Fifty-four different extracts of nine Bolivian plants belonging to the family Asteraceae were evaluated for their radical scavenging activity by the DPPH*, NBT/hypoxanthine superoxide, and (*)OH/luminol chemiluminescence methods, and for their antioxidant activity by the beta-carotene bleaching test. The total phenolic content was also determined by the Folin-Ciocalteu method, and the oxidative stability by the Rancimat test. Both remarkably high phenolic content and radical scavenging and antioxidant activities were found mainly in the ethyl acetate fractions among the different plant extracts. Some ethyl acetate and even some defatted crude extracts exhibited activities comparable to those of commercial extracts/compounds, thus making it possible to consider some of the studied plants as a potential source of antioxidants of natural origin.     

Quantification of polyphenolic antioxidants and free radical scavengers in marine algae

While the health benefits of antioxidant compounds from terrestrial plants are widely accepted in Western counties, there is less recognition of the health benefits of marine algal antioxidant compounds. Oceans are an abundant source of biomaterials, with many natural antioxidants derived from marine algae being investigated as potential anti-aging, anti-inflammatory, anti-bacterial, anti-fungal, cytotoxic, anti-malarial, anti-proliferative, and anti-cancer agents. The aim of this work was to quantify and compare polyphenolic content and free radical scavenging activity of algal extracts using normal phase and reverse phase thin layer chromatography. Post-chromatographic derivatization with neutral ferric chloride (FeCl₃) solution and with 2,2-diphenyl-1-picrylhydrazyl (DPPH·) free radical were used to assess total polyphenolic content and free radical scavenging activities in algal samples. Total phenolic content quantified on normal phase plates was correlated to phenolic content established on reverse phase plates. Similarly, free radical scavenging activity established on normal phase and reverse phase plates were in good agreement. However, although free radical scavenging activities determined on normal phase plates were highly correlated with polyphenolic content, this correlation was low for reverse phase plates. Lipophilic reversed phase TLC plates do not effectively separate mixtures of highly polar compounds like flavonoids, phenolic compounds and their glucosides. Thus, although reversed phase plates are recommended for assessment of free radical scavengers, as they do not influence the free radical-antioxidant reaction, they may not provide the best separation of polar phenolic compounds, especially flavonoids, and therefore may not accurately quantify polyphenolic content and free radical scavenging potential.     

Screening of the antioxidative properties and total phenolic contents of three endemic Tanacetum subspecies from Turkish flora

Methanolic extracts of three different Tanacetum subspecies [Tanacetum densum (Lab.) Schultz Bip. subsp. sivasicum Hub-Mor and Grierson, Tanacetum densum (Lab.) Schultz Bip. subsp. eginense Heywood and Tanacetum densum (Lab.) Schultz Bip. subsp. amani Heywood] which are endemic to Turkish flora were screened for their possible antioxidant activities by two complementary test systems namely DPPH free radical scavenging and beta-carotene/linoleic acid. In DPPH system, the most active plant was T. densum subsp. amani with an IC(50) value of 69.30+/-0.37 microg/ml. On the other hand, T. densum subsp. sivasicum exerted greater antioxidant activity than those of other subspecies in beta-carotene/linoleic acid system (79.10%+/-1.83). Antioxidant activities of BHT, curcumine and ascorbic acid were also determined as positive controls in parallel experiments. Total phenolic constituents of the extracts of Tanacetum subspecies were performed employing the literature methods involving Folin-Ciocalteu reagent and gallic acid as standard. The amount of total phenolics was highest in subsp. sivasicum (162.33+/-3.57 microg/mg), followed by subsp. amani (158.44+/-2.17 microg/mg). Especially, a positive correlation was observed between total phenolic content and antioxidant activity of the extracts.     

Studies on the antioxidant activity and phenolic compounds of enzyme-assisted water extracts from Du-zhong (Eucommia ulmoides Oliv.) leaves

Enzyme-assisted water extracts (EWEDL) and ethanol extracts of Du-zhong leaves (EEDL) were evaluated for their antioxidant activities using the DPPH radical-scavenging assay, Fe²⁺-chelating assay, and inhibition ability of the linoleic acid peroxidation assay. In general, the antioxidant activity of Du-zhong leaf extracts increased with increasing concentration. Based on the two extracting methods with different antioxidative reactions, it was shown that the enzyme-assisted water extracting method was more effective for antioxidant extraction from Du-zhong leaves. By HPLC-MS analysis, the main phenolic compounds (geniposidic acid, epicatechin, and chlorogenic acid) identified in EWEDL and EEDL were similar. EWEDL and EEDL had total phenolic contents of 13.84?±?0.11 and 14.72?±?0.14?mg chlorogenic acid equivalents (CAE) in each gram of extract, respectively. However, there was no positive correlation between total phenolic content and antioxidant activities of EWEDL and EEDL measured by the three different assays.     

Consequence of the antioxidant activities and tyrosinase inhibitory effects of various extracts from the fruiting bodies of Pleurotus ferulae

This study was initiated to screen the antioxidant activities, tyrosinase inhibitory effects on the fruiting bodies of Pleurotus ferulae extracted with acetone, methanol and hot water. The antioxidant activities were performed on β-carotene–linoleic acid, reducing power, DPPH, ferrous ions chelating abilities, and xanthine oxidase. In addition to this, phenolic compounds were also analyzed. The methanolic extract showed the strongest β-carotene–linoleic acid inhibition and high reducing power as compared to other extracts. The scavenging effects on DPPH radicals, the acetonic and methanolic extracts were more effective than hot water extracts. The strongest chelating effect was obtained from the methanolic extract as compared to the tested synthetic antioxidant. Gallic acid, protocatechuic acid, caffeic acid, vanillin, ferulic acid, naringin, resveratrol, naringenin, hesperetin, formononetin and biochanin-A were detected from acetonitrile and hydrochloric acid (5:1) solvent extract. Xanthine oxidase and tyrosinase inhibitory activities of acetonic, methanolic, and hot water extracts of P. ferulae increased with increasing concentration. The results suggested that consumption of P. ferulae might be beneficial to the antioxidant, xanthine oxidase, and tyrosinase protection system of the human body against oxidative damage and others complications.     

Survey of Phytochemical Composition and Biological Effects of Three Extracts from a Wild Plant (Cotoneaster nummularia Fisch. et Mey.): A Potential Source for Functional Food Ingredients and Drug Formulations

This study was focused on the analysis of the phenolic content, antioxidant, antibacterial, anti-cholinesterase, anti-tyrosinase, anti-amylase and anti-glucosidase activity of three solvent extracts from Cotoneaster nummularia. Moreover, water extract was tested in terms of mutagenic/anti-mutagenic effects. The antioxidant activities of these extracts were evaluated by DPPH, ABTS, O₂, metal chelating, phosphomolybdenum, β-carotene/linoleic acid, ferric and cupric reducing power assays. Enzyme inhibitory activities were also examined with colorimetric methods. Generally, methanol and water extracts exhibited excellent biological activities. These extracts were rich in phenolic and flavonoid content. Furthermore, Cotoneaster extracts indicated appreciable antibacterial properties against human pathogen strains. HPLC analysis showed that ferulic acid, chlorogenic acid, (-) – epicatechin and (+)-catechin were the major phenolics in extracts tested. These data offer that these extracts from C. nummularia may be considered as a potential source of biological agents for developing functional foods or drug formulations.     

In vitro Antioxidant and Anti‐inflammatory Activities of Extracts from Nicotiana tabacum L. (Solanaceae) Leafy Galls Induced by Rhodococcus fascians

Plant galls are widely distributed, and their extracts are used in traditional medicine worldwide. Traditional remedies containing extracts of plant galls in China, India and some African countries have effective in the treatment of various pathologies. To open a new promising procedure for screening bioactive compounds from plant galls, standardized plant materials were generated in vitro and used for phytochemical and biological investigations. Methanol aqueous chloroform and hexane extracts of Nicotiana tabacum leafy galls induced by Rhodococcus fascians were used to evaluate phenolic and flavonoid contents, and to investigate antioxidant activity by 2,2‐diphenyl‐1‐picrylhydrazyl radical scavenging and ferric reducing antioxidant/power assays and anti‐inflammatory activity by the lipoxygenase inhibition assay. Infection by R. fascians modifies significantly the phytochemical profile of N. tabacum as well as its biological properties. The total polyphenolic content was increased (120–307%), and that of flavonoids was reduced (20–42.5%). Consequently, antioxidant and anti‐inflammatory activities of non‐infected tobacco extracts are significantly modified compared to plants treated with leafy gall extracts. This shows that infection by R. fascians favoured the production of anti‐inflammatory and antioxidant compounds in N. tabacum. The study indicates the benefit of plant galls used in traditional medicines against various pathologies.