Components In Plant Extracts Research Articles

The protective effect of some Thai plants and their bioactive compounds in UV light-induced skin carcinogenesis

Skin cancer, represents a major public health concern. While the vast majority is non-melanoma skin cancers, melanomas are mostly responsible for mortality. Solar UVB radiation is mutagenic and carcinogenic. It is primarily responsible for both non-melanoma and melanoma skin cancers via excessive production of reactive oxygen species (ROS), which mediate changes in inflammation and immunity, and have been implicated in all three stages of skin cancer development. Due to their regulatory role in numerous functions of cells, signaling pathways are targets for chemoprevention. The current standards in melanoma therapy are targeted and combination therapies, which, albeit prolong survival responses, are still prone to development of drug resistance. To this extent, drugs of natural origin continue to spark great interest. Thailand has a rich biodiversity of indigenous flora, which have traditionally been used to treat a variety of pathologies. The active components in plant extracts that have medicinal properties, termed ‘bioactive compounds,’ are efficient chemopreventive agents due to their antioxidant, antimutagenic, anticarcinogenic, and carcinogen detoxification properties. Thai plants and their bioactive compounds have shown protective effects on UV light-induced skin cancer in different experimental models. This warrants further in vivo investigations and translation to clinical studies to determine efficacy and safety, for use as lead compounds in targeted/combination therapy or adjuvant therapy with existing regimes. Coupled with a strategy for prevention, this offers a promising outlook for protection against photocarcinogenesis.

Microbiological characterization and functionality of set-type yogurt fermented with potential prebiotic substrates Cudrania tricuspidata and Morus alba L. leaf extracts

The objective of this study was to investigate the effect of 2 plant leaf extracts on fermentation mechanisms and health-promoting activities and their potential as a nutraceutical prebiotics ingredient for application in dairy products. The individual active phenolic compounds in the plant extract-supplemented milk and yogurts were also identified. Compared with control fermentation, the plant extracts significantly increased the growth and acidification rate of Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus. In particular, plant extract components, including monosaccharides, formic acid, and hydroxycinnamic acid, such as neo-chlorogenic, chlorogenic, and caffeic acid, together play a stimulatory role and cause this beneficial effect on the growth of yogurt culture bacteria through fermentation. In addition, supplementation with the plant extracts enhanced antioxidant activities with increased total phenolic contents, especially the highest antioxidant activity was observed in yogurt supplemented with Cudrania tricuspidata leaf extract.

Chemical Constituents and Antioxidant Properties of <i>Phyllostachys prominens</i> Gramineae (W Y Xiong ) Leaf Extracts

Purpose: To isolate and identify chemical components of Phyllostachys prominens (Poaceae) leaf extracts, and measure their antioxidant activities. Methods: Ethanol extracts of P. prominens leaves were subjected to different chromatographic methods: macroporous resin column chromatography, Sephadex LH-20 column chromatography, and semi-preparative, reversed-phase (RP) high performance liquid chromatography (HPLC). Plant extract components were identified by ultraviolet spectroscopy (UV), mass spectrometry (MS), and nuclear magnetic resonance spectroscopy (NMR). DPPH (1,1-diphenyl 2-picrylhydrazyl) assay was used to measure the radical scavenging activity of the compounds . Results: We isolated fourteen compounds including six flavonoids, two lignans, two phenolic glycosides, a phenolic acid, a phenylpropanoid, a monoterpene glycoside, and amarusine from the leaves of Phyllostachys prominens. The DPPH assay showed that eleven compounds (compounds 1, 4, 6, 7, 8, 9, 10, 11, 12, 13, and 14) exhibited radical scavenging activity. (The half maximal inhibitory concentration ranged from 33.52 to 100.58 μg/mL). The half maximal inhibitory concentration (IC 50 ) values of compounds 1, 4, 6 and 7 were 33.52, 40.61, 47.10, and 35.84 μg/mL respectively, while the IC 50 of the positive control, butylated hydroxytoluene, was 46.32 μg/mL. Conclusion: Fourteen compounds have been successfully all isolated from Phyllostachys prominens for the first time. Eleven of the compounds have radical scavenging activity. Keywords: Phyllostachys prominens , Phytochemicals, Flavonoids, Lignans, Antioxidant activity

Separation, Identification, and Investigation of Antioxidant Ability of Plant Extract Components Using TLC, LC–MS, and TLC–DPPH•

Ten common phenolic compounds from the extracts of five plant species, that is, Hypericum perforatum L., Matricaria recutita L., Achillea millefolium L., Thymus vulgaris L., and Salvia officinalis L., were separated using optimized thin-layer chromatography (TLC) conditions at normal phase mode and were visualized using Natural Product/Polyethylene Glycol Reagent. Antioxidant properties of components of the extracts were assessed using TLC–DPPH• directly on the TLC plate. Nine out of ten analyzed polyphenols were proved to be radical scavengers. The presence and identity of target substances in plant samples were confirmed by the liquid chromatography–mass spectrometry technique.

Micellar liquid chromatography of plant extracts components

Raw materials quality assessment is a very important factor, enabling products creation up to the international standards. In this investigation, the qualitative composition of bioactive plant extracts has been checked. The tested extracts have been obtained by the use of supercritical carbon dioxide extraction and can be utilized as raw materials in a commercial production of a wide range of many different goods. Plant extracts of raspberry (Rubus idaeus), strawberry (Fragaria ananassa), blackcurrant (Ribes nigrum), aronia (Aronia Medik.), Japanese rose (Rosa rugosa Thunb.) seeds, and palmetto palm (Sabal minor) fruit have been examined. In these extracts, saturated, monounsaturated, and polyunsaturated fatty acids as well as polyphenols have been identified using thin-layer chromatography (TLC) with aqueous-organic mobile phases. Appropriate content of these components tends to be a determinant of human organism operation. In our investigation, the plant extract components, especially saturated and unsa...

Combined effects of testosterone propionate and Leptadenia hastata Pers. (Decne) aqueous extracts on immature castrated male rats

To evaluate the competition between testosterone propionate (TP) and Leptadenia hastata aqueous extracts, immature castrated male Wistar rats were divided into two groups. L. hastata aqueous extracts reduced significantly the weight of androgen-dependant sex glands, the level of phosphatase acid prostatic (PAP) and fructose in seminal vesicles and prostate, and the serum testosterone level. When TP was administered simultaneously with 100, 200 and 400 mg/kg of L. hastata aqueous extracts, a potentiate action was observed with 100 mg/kg of L. hastata by the increase of androgen-dependant sex glands weights, fructose and PAP levels in seminal vesicles and prostate, and the serum testosterone level. The anti-androgenic effect of L. hastata appeared with the doses of 200 and 400 mg/kg which reduced significantly the weight of androgen-dependant sex glands, fructose and PAP levels in seminal vesicles and prostate and serum testosterone level. From these findings, it was concluded that the effect of TP was potentiated with low doses of L. hastata and antagonized with high doses. This study confirmed the anti-androgenic effects of L. hastata aqueous extracts in immature castrated male rats. Key words: Leptadenia hastata , testosterone propionate, anti-androgenic activity, rats. INTRODUCTION The increasing interest in the effects of the components of plant extracts on humans and wildlife has been reflected in the number of recent papers and international conferences devoted to this topic (Weisburger, 1999; Arbonnier, 2000; Vasudeva and Sharma, 2006). Plant-derived chemicals that influence endocrine activities in both humans and animals have received a great deal of attention due to their possible beneficial as well as adverse effects (Gamache and Acworth, 1998). Leptadenia hastata (Pers.) Decne (Asclepediaceae) is an indigenous medicinal plant of West Africa, commonly

A fluorescence-based analysis of aristolochic acid-derived DNA adducts

Aristolochic acids (AAs), major components of plant extracts from Aristolochia species, form (after metabolic activation) pro-mutagenic DNA adducts in renal tissue. The DNA adducts can be used as biomarkers for studies of AA toxicity. Identification of these adducts is a complicated and time-consuming procedure. We present here a fast, nonisotopic, fluorescence-based assay for the detection of AA–DNA adducts in multiple samples. This approach allows analysis of AA adducts in synthetic DNA with known nucleotide composition and analysis of DNA adducts formed from chemically diverse AAs in vitro. The method can be applied to compare AA–DNA adduct formation in cells and tissues.

Interaction between Plectranthus barbatus herbal tea components and acetylcholinesterase: binding and activity studies

Plectranthus barbatus water extracts, have been used as herbal teas, for the treatment of various diseases. In a previous study it was demonstrated that antioxidant and anti-acetylcholinesterase active extract constituents and their metabolites were found in the plasma of rats after P. barbatus tea intraperitoneal administration. Consequently, a decrease in brain acetylcholinesterase activity occurred. The aim of the present research is to elucidate how P. barbatus extract components interact with acetylcholinesterase. The estimated thermodynamic parameters suggest that the main intermolecular interaction is hydrophobic association, although hydrogen bonds between flavonoids and the active gorge of the acetylcholinesterase molecule seem to occur and have a great impact on acetylcholinesterase inhibition. The hydroxyl positions in flavonoids seem to be of utmost importance for enzyme inhibition, as they interact with specific amino acid residues in the active gorge. FTIR analysis showed that the plant extract components do not interfere with the secondary structure of the enzyme, but decreases the rate of hydrogen-deuterium exchange, possibly by decreasing solvent accessibility in the acetylcholinesterase active gorge. The spectroscopic data complements docking studies of acetylcholinesterase inhibition by plant phenolic compounds, clarifying the dominant interactions between enzyme and inhibitor and the most important structural features of the inhibitor molecules.

Interaction betweenPlectranthus barbatusherbal tea components and human serum albumin and lysozyme: Binding and activity studies

Anti-cholinesterase and antioxidant active constituents ofPlectranthus barbatusaqueous extract were found in plasma of rats after its administration – rosmarinic acid, luteolin and apigenin. The aim of the present work is to determine if the extract components can interact with human plasma proteins, namely albumin and lysozyme. Protein intrinsic fluorescence analysis showed that the plant phenolic compounds may bind to albumin, the main transport protein in plasma, and to lysozyme. The estimated thermodynamic parameters suggest that the main intermolecular interaction is hydrophobic association. FTIR analysis of the protein amide bands showed that the plant extract components do not alter the secondary structure of either albumin or lysozyme, however the rate of hydrogen–deuterium exchange suggests that tertiary structure changes might have occurred. An increase of hydrogen deuterium exchange suggests that rosmarinic acid may bind to the fatty acid binding sites in albumin, while luteolin and apigenin may bind to the drug binding sites. The plant extract components also inhibit lysozyme activity with IC50values around 100 μM. ThereforeP. barbatusherbal tea, rosmarinic acid, luteolin and apigenin interact and may be transported by albumin and lysozyme. The inhibition of lysozyme activity may be an additional mechanism for its anti-inflammatory activity.

Interaction between Plectranthus barbatus herbal tea components and human serum albumin and lysozyme: Binding and activity studies

Anti-cholinesterase and antioxidant active constituents of Plectranthus barbatus aqueous extract were found in plasma of rats after its administration - rosmarinic acid, luteolin and apigenin. The aim of the present work is to determine if the extract components can interact with human plasma proteins, namely albumin and lysozyme. Protein intrinsic fluores- cence analysis showed that the plant phenolic compounds may bind to albumin, the main transport protein in plasma, and to lysozyme. The estimated thermodynamic parameters suggest that the main intermolecular interaction is hydrophobic associa- tion. FTIR analysis of the protein amide bands showed that the plant extract components do not alter the secondary structure of either albumin or lysozyme, however the rate of hydrogen-deuterium exchange suggests that tertiary structure changes might have occurred. An increase of hydrogen deuterium exchange suggests that rosmarinic acid may bind to the fatty acid binding sites in albumin, while luteolin and apigenin may bind to the drug binding sites. The plant extract components also inhibit lysozyme activity with IC50 values around 100 µM. Therefore P. barbatus herbal tea, rosmarinic acid, luteolin and apigenin interact and may be transported by albumin and lysozyme. The inhibition of lysozyme activity may be an additional mechanism for its anti-inflammatory activity.

TLC of Alkaloids on Cyanopropyl Bonded Stationary Phases. Part II. Connection with RP18 and Silica Plates

Some standards of the alkaloids and synthetic or natural mixtures are separated by two-dimensional thin-layer chromatography (TLC) on different adsorbent layers. Normal- and reversed-phase systems are used to obtain significant differences in the separation selectivity. Optimization of the one-dimensional TLC separation of the alkaloids' standards is performed on cyanopropyl-silica, RP18W, and silica layers in various eluents containing (besides diluent and modifier) silanol blockers, such as diethyl amine or ammonia. The most selective systems are used for the separation of the alkaloids' mixtures by two-dimensional TLC with an adsorbent gradient method. The mixtures of alkaloids or plant extracts (Chelidonium majus, Fumaria officinalis, or Glaucium flavum) are chromatographed in system I; the plates are connected with the plate pre-coated with various adsorbent, and partly separated fractions are transferred to the second layer and developed in system II. CN-silica-RP18W and CN-silica-silica are used as the connected layers. The alkaloids are identified by R(F) values of standards, and the components of plant extracts are identified in both systems, and by the comparison of UV spectra obtained in diode array detector densitometry.

Galbanic Acid from Ferula szowitsiana Enhanced the Antibacterial Activity of Penicillin G and Cephalexin against Staphylococcus aureus

In this study the enhancement effect of Ferula szowitsiana roots' acetone extract on the antibacterial activity of penicillin G and cephalexin was evaluated against Staphylococcus aureus. Disk diffusion and broth dilution methods were used to determine the antibacterial activity of these antibiotics in the absence and presence of plant extract and its various fractions separated by TLC plate. The active component of plant extract involved in enhancement of penicillin G's and cephalexin's activities had Rf=0.336 on a TLC plate. The spectral data ((1)H-, (13)C-NMR) of this compound revealed that this compound was 7-[6-(beta-carboxyethyl)-5-isopropylidene-1,2-dimethylcyclo-hexylmethoxy]coumarin (galbanic acid), previously isolated from Ferula assa-foetida. In the presence of sub-inhibitory concentration of galbanic acid (100 microg/ml) the MIC of penicillin G for S. aureus decreased from 64 to 1 (a sixteen four-fold decrease) and for cephalexin from 128 to 1 microg/ml (a one hundred twenty eight-fold decrease). The highest fold decrease in MIC was observed for cephalexin in combination of galbanic acid against test strain. These results signify that the low concentration of galbanic acid (100 microg/ml) potentiates the antimicrobial action of penicillin G and cephalexin suggesting a possible utilization of these compounds in combination therapy against S. aureus.

Ultra low concentrations of sophoraflavanone G from Sophora pachycarpa C. Meyer enhanced the antibacterial activity of gentamycin aginst Staphylococcus aureus

In this study the enhancement effect of Sophora pachycarpa roots' acetone extract on the antibacterial activity of gentamycin was evaluated against Staphylococcus aureus. Disk diffusion and broth dilution methods were used to determine the antibacterial activity of gentamycin in the absence and presence of plant extract and its various fractions separated by TLC. Clinical isolate of S. aureus was used as test strain. The active component of plant extract involved in enhancement of gentamycin's activity had Rf =0.72 on TLC. The spectral data (1H NMR, 13C NMR) of this compound revealed that this compound was 5,7,2',4'-tetrahydroxy-8-lavandulylflavanone (sophoraflavanone G), previously isolated from Sophora exigua. In the presence of 0.03 mcg/mL of sophoraflavanone G the MIC of gentamycin for S. aureus decreased from 32 to 8 mcg/mL (a fourfold decrease). These results signify that the ultra low concentration of sophoraflavanone G potentiates the antimicrobial action of gentamycin suggestion a possible utilization of this compound in combination therapy against S. aureus.

Aqueous Vernomia amygdalina extracts alter MCF-7 cell membrane permeability and efflux.

Breast cancer is the second leading cause of cancer related deaths of women in the United States. Several treatment strategies have been developed over the past decade to reduce cancer morbidity and mortality rates. While mortality rates have declined in some ethnic populations, the overall cancer incidence continues to grow. Hence, chemotherapeutic agents are needed to improve cancer treatment outcome. Previous studies show that low concentrations (microgram/ml) of water-soluble leaf extracts of a Nigerian edible plant, V. amygdalina (VA), potently retard the proliferative activities of estrogen receptor positive (ER+) human breast cancerous cells (MCF-7) cells in vitro in a concentration-dependent fashion. The anti-proliferative activities of VA are extracellular signal-regulated kinases (1/2) (ERKs (1/2))-dependent. Cell culture and animal model studies, conducted by other investigators using other plant extracts, have also revealed that plant extract components called thionins may be responsible for their anticancer activities. These thionins are believed to interact with the cells in ways that compromise membrane potential/permeability resulting in the alteration of efflux, cytosolic activities, and subsequent cell death. Therefore, we hypothesized that VA exposure may compromise cell membrane as another mode of action to elicit its anticancer activities in MCF-7 cells. The exposure of cells to VA decreased [3H]thymidine uptake in a concentration-dependent (0, 30, and 100 mug/ml VA) manner (p < 0.05) but increased [3H]thymidine release, expressed as percent of [3H]thymidine incorporated, into the medium (p < 0.05). The amount of [3H]thymidine released into the medium was 1.7, 7.4, and 11.0 % for 0, 30, and 100 mug/ml VA respectively. Thus suggesting the membranes in VA-treated cells were compromised in a concentration-dependent fashion.

Analysis of Some Natural Antioxidants by Thin‐Layer Chromatography and High Performance Thin‐Layer Chromatography

(HP)TLC is a technique with large applicability in the fields of plant material analysis and stability tests of extracts and finished products. The implementation of a modern standardized methodology led to the increasing of acceptance and recognition of (HP)TLC as competitive analytical method. (HP)TLC has many advantages, such as lower costs, short time analysis, the possibility of multiple detection, and specific derivatization on the same plate, etc. The natural antioxidants (polyphenols) are present in plant extracts; they play a key role in antioxidative defence mechanisms in biological systems and they act as free radicals scavenging agents. The separation of polyphenols from each other and from other components of the plant extracts can be done by a great number of (HP)TLC developed techniques. Mostly, complex crude plant extracts are screened for antioxidant activity or to distinguish the components of plant extracts with antioxidant character or radical‐scavenging properties. (HP)TLC has been used for the determination of individual antioxidant capacity of target compounds and it might be of interest to the routine chemical or biological screening and they can solve real analytical problems.

Diosgenin induces cell cycle arrest and apoptosis in HEL cells with increase in intracellular calcium level, activation of cPLA2 and COX-2 overexpression

Many natural components of plant extracts are studied for their beneficial effects for health and particularly on carcinogenesis chemoprevention. In the present study, we investigated the effects of diosgenin on erythroleukemia HEL cells. Our results demonstrated that diosgenin induced G2/M arrest of cell cycle progression through p21 up-regulation in a p53-independent pathway and strong induction of apoptosis in HEL cells. Apoptosis induction was accompanied by an increase in Bax/Bcl-2 ratio, PARP cleavage and DNA fragmentation. Moreover, we showed for the first time that diosgenin provoked a collapse of mitochondrial membrane potential with an increase in intracellular calcium levels. It is well known that [Ca2+]i increase is one of the major activators of cytosolic PLA2. In our study, we demonstrated that diosgenin treatment induced cPLA2 activation through translocation to the cellular membrane. Moreover, arachidonic acid metabolism activation led to cyclooxygenase-2 (COX-2) but not lipoxygenase overexpression. Surprisingly, we observed a COX-2 up-regulation associated with apoptosis induction by diosgenin. These findings suggest that diosgenin has a potential chemopreventive effect; future studies should evaluate the mechanism of COX-2 activation during diosgenin-induced apoptosis in cancer cell lines.

HPLC micro-fractionation coupled to a cell-based assay for automated on-line primary screening of calcium antagonistic components in plant extracts.

High performance liquid chromatography (HPLC) micro-fractionation was successfully coupled to an automated 45Ca2+ uptake assay using GH4C1 cells for the separation of natural product extracts and for the primary detection of their calcium antagonistic components. The reliability of the procedure was first established with a reference solution consisting of pure compounds with a known effect on the Ca2+ uptake. No loss of activity was observed to occur after HPLC micro-fractionation. Extracts of Peucedanum palustre and Pinus sylvestris, showing high and no inhibition of Ca2+ uptake as total extracts, respectively, were analysed and the inhibitory activity of the P. palustre extract could be traced to two components, identified as columbianadin and isoimperatorin. As expected, no significant inhibition was observed with the micro-fractionated P. sylvestris samples. In summary, the procedure was found to be applicable for primary detection of calcium antagonistic components in complex matrices and to significantly reduce the time previously needed for bioactivity-guided isolation.

Comparison of conventional and ultrasound‐assisted extraction of carvone and limonene from caraway seeds

AbstractExtraction experiments with hexane were carried out at atmospheric pressure in Soxhlet, conventional and ultrasound extractions of flaked caraway seeds, and detailed results are given for two major plant extract components, carvone and limonene. The results indicate that carvone yield and plant extract quality are better in ultrasound extraction compared to those given by conventional methodology. Extraction rates of carvone and limonene reported that ultrasound‐assisted extraction was 1.3–2 times more rapid, depending on temperature, than a conventional system, according to the rate constant obtained during the initial 10 minutes of extraction. Moreover, the SEM micrographs provided more evidence for the mechanical effects of ultrasound, mainly appearing on cell walls and shown by the destruction of cells, faulitating the release of their contents, in contrast to conventional maceration or extraction, which involve diffusion of plant extracts across glandular walls and causing cell rupture over longer time periods. Copyright © 2004 John Wiley &amp; Sons, Ltd.

Cell surface interactions of Rhizobium bacteroids and other bacterial strains with symbiosomal and peribacteroid membrane components from pea nodules.

Samples of Rhizobium bacteroids isolated from pea nodule symbiosomes reacted positively with a monoclonal antibody recognizing N-linked glycan epitopes on plant glycoproteins associated with the peribacteroid membrane and peribacteroid fluid. An antiserum recognizing the symbiosomal lectin-like glycoprotein PsNLEC-1 also reacted positively. Samples of isolated bacteroids also reacted with an antibody recognizing a glycolipid component of the peribacteroid membrane and plasma membrane. Bacterial cells derived from free-living cultures then were immobilized on nitrocellulose sheets and tested for their ability to associate with components of plant extracts derived from nodule fractionation. A positive antibody-staining reaction indicated that both PsNLEC-1 and membrane glycolipid had become associated with the bacterial surface. A range of rhizobial strains with mutants affecting cell surface polysaccharides all showed similar interactions with PsNLEC-1 and associated plant membranes, with the exception of strain B659 (a deep-rough lipopolysaccharide mutant of Rhizobium leguminosarum). However, the presence of a capsule of extracellular polysaccharide apparently prevented interactions between rhizobial cells and these plant components. The importance of a close association between peribacteroid membranes, PsNLEC-1, and the bacterial surface is discussed in the context of symbiosome development.

Detection and activity evaluation of radical scavenging compounds by using DPPH free radical and on-line HPLC-DPPH methods

The antiradical activity of crude extracts (80% methanol, 20% water) of S. officinalis, S. glutinosa, S. sclarea and S. aethiopis was determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH·) radical scavenging method. For validation of this method several well known antioxidants (ascorbic acid-6-palmitate, gallic, chlorogenic, ferulic, caffeic, uric, gentisic and vanillic acids, catechin, quercetin, epicatechin, phloridzin, rutin and naringin) were investigated additionally. In these experiments ascorbic acid-6-palmitate had highest antiradical activity. Within the group of phenolic acids gentisic acid had the highest antiradical activity comparing with the other tested phenolic acids. Uric acid, vanillic acid, phloridzin and naringin have a much lower antiradical activity. Different reaction kinetics behaviour was observed. The validated DPPH radical scavenging method was applied to the evaluation of the antiradical activity of plant extracts. The Salvia extracts showed very high antiradical activity towards the DPPH·. An on-line HPLC-DPPH method was developed using a methanolic solution of DPPH· for a rapid detection of radical scavenging components after HPLC separation. The HPLC-DPPH on-line method was also applied to a screening of several radical scavenging components in plant extracts as well as for quantitative analysis. The HPLC analysis revealed the presence of several radical scavenging components in the all Salvia extracts. This HPLC-DPPH on-line method can also be used for quantitative determination of radical scavenging compounds.