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At least 217 records · Page 12Linked to original sources
PubMed2005

Screening of Yucatecan plant extracts to control Colletotrichum gloeosporioides and isolation of a New Pimarene from Acacia pennatula.

Screening of seven Yucatecan plant extracts to look for fungicidal activity for the control of Colletotrichum gloeosporioides was carried out. Bioassay-directed purification of the root extract of one of the most active plants, Acacia pennatula, resulted in the isolation of the new compound 15,16-dihydroxypimar-8(14)-en-3-one (1), which in the in vitro bioassay "agar dilution" was shown to have growth, sporulation, and germination inhibition activity. Nuclear magnetic resonance spectroscopic techniques were used to elucidate its structure.

Abietanes↗
PubMed1992

Effects of Phyllanthus plant extracts on duck hepatitis B virus in vitro and in vivo.

The effects of extracts of five Australian Phyllanthus species (P. hirtellus, P. gunnii, P. gasstroemii, P. similis and P. tenellus), other plant extracts and the antiviral drug foscarnet on duck hepatitis B virus (DHBV) endogenous DNA polymerase (DNAp) activity were compared. All 5 Phyllanthus species caused 50% inhibition at concentrations of dry weight between 350-800 micrograms/ml, which is comparable with the effect described for P. amarus on the DNAp of human and woodchuck hepatitis B viruses. Incubation of P. hirtellus with 100 ID50 DHBV neutralized infection. However, neither P. gasstroemi extract, given by intraperitoneal injection (i.p.) at a dose of 20 mg/kg 3 times per week to ducklings early in the incubation period, or P. hirtellus extract, given to established DHBV carrier ducklings, prevented or eliminated infection.

Animals↗
PubMed1995

Larvicidal activity of a few plant extracts against Culex quinquefasciatus and Anopheles stephensi.

Larvicidal activity of partially purified extracts of leaves of Vitex negundo, Nerium oleander and seeds of Syzygium jambolanum on different instars of Culex quinquefasciatus and Anopheles stephensi was estimated. Petroleum ether (PE): Ethyl acetate (EA) 3:1 fraction of V. negundo, 1:1 fractions of N. oleander and S. jambolanum inflicted considerable larval mortality and interfered with pupal-adult metamorphosis. At very low concentration the active fractions of these plant extracts extended the duration of the various larval instars and of pupation. In general, I and II instar larvae were more susceptible to the active fractions. Species and stage specific differences in the susceptibility of the mosquitoes to the active fractions of the plant extracts were observed.

Animals↗
PubMed2000

Antimicrobial effects of Finnish plant extracts containing flavonoids and other phenolic compounds.

Plant phenolics, especially dietary flavonoids, are currently of growing interest owing to their supposed functional properties in promoting human health. Antimicrobial screening of 13 phenolic substances and 29 extracts prepared from Finnish plant materials against selected microbes was conducted in this study. The tests were carried out using diffusion methods with four to nine microbial species (Aspergillus niger, Bacillus subtilis, Candida albicans, Escherichia coli, Micrococcus luteus, Pseudomonas aeruginosa, Saccharomyces cerevisiae, Staphylococcus aureus and Staphylococcus epidermidis). Flavone, quercetin and naringenin were effective in inhibiting the growth of the organisms. The most active plant extracts were purple loosestrife (Lythrum salicaria L.) against Candida albicans, meadowsweet (Filipendula ulmaria (L.) Maxim.), willow herb (Epilobium angustifolium L.), cloudberry (Rubus chamaemorus L.) and raspberry (Rubus idaeus L.) against bacteria, and white birch (Betula pubescens Ehrh.), pine (Pinus sylvestris L.) and potato (Solanum tuberosum. L.) against gram-positive Staphylococcus aureus.

Anti-Bacterial Agents↗
PubMed2005

Colophonium and Compositae mix as markers of fragrance allergy: cross-reactivity between fragrance terpenes, colophonium and compositae plant extracts.

The aim of this study was to assess the strength of any association between sensitization to 'new' fragrance compounds and sensitization to Compositae, fragrance mix, Myroxylon pereirae resin and colophonium, respectively. Consecutive eczema patients were tested with a series of essential oils and selected fragrance compounds and another series of oxidized terpenes in connection with European multicentre fragrance projects. Contact allergy to either series was frequently detected, in 5% of 318 and 4.6% of 262 persons tested, and both had a statistically significant association with Compositae, colophonium and fragrance mix sensitization. The individual results indicated that simultaneously occurring positive reactions to essential oils, colophonium and Compositae were based on cross-reactivity rather than concomitant sensitization. Thus, all patients with positive reaction to the rare fragrance sensitizer beta-caryophyllene had positive colophonium reactions, and cross-reactivity between essential oils and Compositae was related to the Compositae plant extracts of the Compositae mix and not the pure sesquiterpene lactones of the standard series. The implication is that Compositae mix and colophonium may be markers of fragrance allergy, which is important to know when assessing the relevance of positive reactions to Compositae plant extracts and colophonium.

Adult↗
PubMed2000

Determination of low-abundant metabolites in plant extracts by NAD(P)H fluorescence with a microtiter plate reader.

This article describes a method for the enzymatic detection of low-abundant metabolic intermediates in plant extracts via NAD(P)H fluorescence using a microtiter plate reader. The detection of changes in NAD(P)H fluorescence (excitation 340 nm, emission 465 nm) exhibits a high signal-to-noise ratio and is as sensitive (> or = 20 pmol per well) as absorbance measurements with dual-wavelength photometers. Since up to 96 reactions can be initiated, monitored, and evaluated simultaneously, this method might be suitable for high-throughput screening programs on metabolite profiles. However, in contrast to absorbance measurements, fluorescence detection of NAD(P)H yields relative data, which can be impaired by the quench characteristics and the basic fluorescence of the extracts. Hence, extensive calibration is required to gain reproducible results. Calibration of the assay system was performed using leaf or root material (equivalent to 2-35 mg of fresh weight per well) extracted with perchloric acid, chloroform/water/methanol, or hot ethanol. Extraction with perchloric acid was found to be superior for metabolite quantification. Examples of the kinetics of individual metabolite determinations are presented and the contents of 3-phosphoglycerate, hexose phosphates, triose phosphates, pyruvate, and phosphoenolpyruvate in illuminated and darkened spinach leaves as well as leaf rosettes of Arabidopsis thaliana and leaf segments of the inducible crassulacean acid metabolism plant Mesembryanthemum crystallinum were measured via NAD(P)H fluorescence and, where possible, compared to reported data determined with dual-wavelength photometers.

Arabidopsis↗
PubMed2000

Stimulatory effect of some plant extracts used in homeopathy on the phagocytosis induced chemiluminescence of polymorphonuclear leukocytes.

Some plant extracts on a large range of dilutions as used in Homeopathy were tested on the chemiluminescence emission produced by polymorphonuclear leukocytes. The high stimulatory action was noticed when extracts from Uvae Ursi and Saponaria were tested, as the classical effect exerted by zymosan was exceeded. A moderate stimulatory action comparable with that of zymosan was found when extracts from Echmaceea, Aleo and Prumis were used, as well as in the case of Propolis. The relationship between stimulatory effect and the concentration range is modulated as function of the extract source, several peaks being observed for some dilutions (Saponana), but generally no quantitative relations were obtained. By studying the time when a chemiluminescence peak was observed, it is possible to estimate wether the weight of the NADPH oxidase or myeloperoxidase pathways are involved in the stimulatory effect on polymorphonuclear leukocytes.

Arctostaphylos↗
PubMed2001

Oxygen radical absorbance capacity of the phenolic compounds in plant extracts fractionated by high-performance liquid chromatography.

The oxygen radical absorbance capacity (ORAC) assay has been used to quantify the antioxidative properties of phytonutrients in fruit and vegetable extracts. Using aqueous methanol extracts of tea and spinach as a model systems, separation of the components in the extracts by HPLC followed by semiautomatic ORAC analysis of the column fractions permitted the determination of peroxyl-radical-scavenging profiles, demonstrating the relative abilities of the individual extract components to scavenge peroxyl radicals. ORAC values for up to 80 HPLC fractions were measured, confirming the major contribution of epigallocatechin gallate in the peroxyl radical scavenging of green tea extracts. Although the flavonoids in spinach extracts provided resistance to peroxyl radicals, components that did not bind to the HPLC column and simple phenolic compounds may also be important contributors to the total ORAC activity of spinach leaf extracts. Application of these procedures to plants believed to provide certain human health benefits by reducing free radicals may allow the identification and characterization of the specific components responsible for the free-radical-scavenging activities.

Antioxidants↗
PubMed1998

Anti-nociceptive and anti-inflammatory effects of some Jordanian medicinal plant extracts.

The anti-nociceptive effect of ethanolic extract of 11 traditionally used Jordanian plants was studied by using the acetic acid-induced writhing and hot-plate test in mice. The anti-inflammatory effect of these plants was determined by xylene-induced ear oedema in mice and cotton pellet granuloma test in rats. Mentha piperita, Cinnamomum zeylanicum, Apium graveolens, Eucalyptus camaldulentis, and Ruta graveolens possess an anti-nociceptive effect against both acetic acid-induced writhing and hot plate-induced thermal stimulation. M. piperita, Jasminum officinale, Commiphora molmol, and Beta vulgaris possess an anti-inflammatory effect against acute (xylene-induced ear oedema) and chronic (cotton-pellet granuloma) inflammation. The anti-nociceptive and anti-inflammatory effects were dose dependent. These data affirm the traditional use of some of these plants for painful and inflammatory conditions.

Analgesics↗
PubMed2001

Anti-HIV activity of medicinal plant extracts.

As part of our screening of anti-AIDS agents from natural sources, ethanolic and aqueous extracts of 15 medicinal plants widely used in the folk medicine of the Iberian Peninsula were evaluated in vitro. Most of the extracts tested were relatively nontoxic to human lymphocytic MT-2 cells, but only the extracts of Tuberaria lignosa and Sanguisorba minor magnolii exhibited anti-HIV activity in an in vitro MTT assay. The aqueous extracts of these plants showed inhibitory effects against HIV-1 induced infections in MT-2 cells at concentrations ranging from 12.5 to 50 microg/ml and 50 microg/ml, respectively. Both extracts showed no appreciable cytotoxicity at these concentrations.

Anti-HIV Agents↗
PubMed1999

Antiviral activity of Bolivian plant extracts.

Ethanolic and aqueous extracts of seven plant species used in the traditional medicine of Bolivia have been tested for their antiviral activity against herpes simplex type I (HSV-1), vesicular stomatitis virus (VSV), and poliovirus type 1. The aqueous extracts of most of the species investigated showed antiviral activity. Two of these plants-namely, Satureja boliviana and Baccharis genistelloides-were active against two different viruses-HSV-1 and VSV.

Animals↗
PubMed1980

Influence of lipidic plant extracts on carrageenin-induced inflammation of guinea-pig palatal mucosa.

Inflammation was induced in the guinea-pig palatal mucosa by a carrageenin solution injection. The inflammatory process was studied by a stereologic procedure. A determination was made of the volume fraction occupied by collagen, edema and vessels 1, 3, 6, 12, 24 hours and 4 days after the injection. The non-treated animals group presented a maximal collagen volumetric density decrease 6 hours after the carrageenin injection. The volume fraction of collagen then increased to reach approximately a value similar to the healthy mucosa collagen volumetric density 4 days after the injection. Edema was correlatively maximal 6 hours after the carrageenin injection and decreased during the next hours. During the whole course of the experiment, the volumetric density of vessels was higher than in healthy mucosa. The modification of the inflammatory process in the group of animals treated by the lipidic plants extracts (15 mg daily during 60 days before the carrageenin injection) mainly consisted in a stabilization of the vessels volumetric density during the experiment. The lipidic plants extracts would act as an inhibiting factor of the inflammatory vascular neoformation.

Animals↗
PubMed1993

Regulation of the expression of a pelA::uidA fusion in Erwinia chrysanthemi and demonstration of the synergistic action of plant extract with polygalacturonate on pectate lyase synthesis.

The phytopathogenicity of Erwinia chrysanthemi is chiefly supported by the production of pectate lyase isoenzymes, encoded by the pel genes. One of these enzymes, PelA, encoded by the pelA gene, seems to represent only a small part of the total pectate lyase activity, but is required for full bacterial pathogenicity. To study the regulation of pelA gene expression, a pelA::uidA gene fusion was constructed. Expression of this fusion was analysed under various growth conditions and in various genetic backgrounds. Whatever the culture conditions, the pelA gene was weakly expressed. Moreover, pelA expression seems not to be regulated by the pecS gene product, but essentially by the kdgR gene product. In many plant-associated bacteria, genes involved in pathogenicity are induced by certain plant compounds. In this work, we demonstrate that E. chrysanthemi pel genes are induced in the presence of plant extracts, but only in synergy with known pectate lyase inducers (KDG: 2-keto-3-deoxygluconate; DKII: 2,5-diketo-3-deoxygluconate). However, different pel genes did not exhibit the same sensitivity to plant signal molecules. Partial purification of inducing plant compounds suggested that plant extracts contain at least one molecule involved in pectate lyase induction. This compound is thermoresistant, and has a low molecular mass and a very hydrophilic behaviour.

Carbohydrate Sequence↗
PubMed2004

Metabolite profiling and chemopreventive bioactivity of plant extracts from Bidens pilosa.

Bidens pilosa has been used as a folk medicine in various medications and as a popular ingredient in herb teas. Chemopreventive activities of crude and fractionated plant extracts of Bidens pilosa were evaluated in this study. Ethyl acetate and butanolic fractions, partitioned from the total crude extract of Bidens pilosa, exhibited significant scavenging free radical activity (IC(50) values approximately = with 14-17 microg/mL) comparable to that of alpha-tocopherol. Strong effects on the inhibition of LPS-mediated nitric oxide production in RAW 264.7 cells were also observed for the EA and BuOH fractions. Detectable cytotoxicity on RAW 264.7 cells, however, was observed for the EA fraction at a dose >100 microg/ml. The metabolite profile and major constituents of the BuOH fraction were studied and characterized using various spectroscopic analyses. A new compound, heptanyl 2-O-beta-xylofuranosyl-(1-->6)-beta-glucopyranoside (1), and eight phenolic compounds, namely quercetin 3-O-rabinobioside (2), quercetin 3-O-rutinoside (3), chlorogenic acid (4), 3,4-di-O-caffeoylquinic acid (5), 3,5-di-O-caffeoylquinic acid (6), 4,5-di-O-caffeoylquinic acid (7), jacein (8), centaurein (9) were for the first time isolated from Bidens pilosa. Compounds 2-7 are the major antioxidative constituents in the Bidens pilosa extract.

Animals↗
PubMed2006

The response of gastrointestinal microbiota to avilamycin, butyrate, and plant extracts in early-weaned pigs.

An experiment was designed to evaluate the effects of 3 different additives on the gastrointestinal microbiota of early-weaned pigs. Early-weaned (18 to 22 d; n = 32) pigs (6.0 +/- 0.10 kg of BW) from 8 litters were randomly distributed into 8 pens. Each pen was assigned 1 of 4 dietary treatments: a prestarter or control diet, the control diet with 0.04% avilamycin (AB), with 0.3% sodium butyrate, or with 0.03% plant extract mixture (XT; standardized mixture with 5% (wt/wt) carvacrol extracted from Origanum spp., 3% cinnamaldehyde extracted from Cinnamonum spp., and 2% capsicum oleoresin from Capsicum annum). At the end of the experimental period, 8 pigs per treatment were killed, and samples of their intestinal content were taken. The total bacterial load along the gastrointestinal tract (GIT; stomach, jejunum, cecum, and distal colon) and the lactobacilli and enterobacteria in the jejunum and cecum were measured by quantitative PCR. The total microbial counts along the GIT did not differ among the diets, but there was an increase in the lactobacilli:enterobacteria ratio in the cecum of the piglets on the XT diet (P = 0.003). Restriction fragment length polymorphism of the PCR-amplified V3, V4, and V5 regions of the 16S rDNA gene showed changes in the structure of the microbial community in the jejunum. Dendrograms grouped animals by diets; control with 0.3% sodium butyrate was the treatment that promoted the biggest changes in the microbial ecosystem, followed by AB and then XT. Biodiversity increased when using additives compared with the control diet (P = 0.002). Microbial metabolic activity along the hindgut was studied using the concentration of purine bases and carbohydrase activities. Different patterns for purine bases were observed between diets (diet x intestinal section, P = 0.01). The control diet reached a maximum purine base concentration at the end of the colon, whereas that of the AB diet was reached at the cecum. We could not detect any cellulase or xylanase activities in animals of this age. Appreciable amylase and amylopectinase activities were found, but they did not differ between diets. The results suggest that the effects of avilamycin, butyrate, or the plant extract would not be related to a reduction in the number of total bacteria inhabiting different sections of the GIT but rather to changes in the ecological structure and metabolic activity of the microbial community.

Animal Feed↗
PubMed1993

Comparison of finasteride (Proscar), a 5 alpha reductase inhibitor, and various commercial plant extracts in in vitro and in vivo 5 alpha reductase inhibition.

Human prostate was used as a source of 5 alpha reductase. Compounds were incubated with an enzyme preparation and [3H]testosterone. [3H]-dihydrotestosterone production was measured to calculate 5 alpha reductase activity. IC50 values (ng/ml) were finasteride = 1; Permixon = 5,600; Talso = 7,000; Strogen Forte = 31,000; Prostagutt = 40,000; and Tadenan = 63,000. Bazoton and Harzol had no activity at concentrations up to 500,000 ng/ml. In castrate rats stimulated with testosterone (T) or dihydrotestosterone (DHT), finasteride, but not Permixon or Bazoton, inhibited T stimulated prostate growth, while none of the three compounds inhibited DHT stimulated growth. These results demonstrate that finasteride inhibits 5 alpha reductase, while Permixon and Bazoton have neither anti-androgen nor 5 alpha reductase inhibitory activity. In addition, in a 7 day human clinical trial, finasteride, but not Permixon or placebo, decreased serum DHT in men, further confirming the lack of 5 alpha reductase inhibition by Permixon. Finasteride and the plant extracts listed above do not inhibit the binding of DHT to the rat prostatic androgen receptor (concentrations to 100 micrograms/ml). Based on these results, it is unlikely that these plant extracts would shrink the prostate by inhibiting androgen action or 5 alpha reductase.

5-alpha Reductase Inhibitors↗