PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Plant Extracts”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 163 records · Page 9Linked to original sources
PubMed2006

Thiobarbituric acid reactive substances and volatile compounds in chicken breast meat infused with plant extracts and subjected to electron beam irradiation.

The effect of irradiation on thiobarbituric acid reactive substances (TBARS) and volatile compounds in raw and cooked nonirradiated and irradiated chicken breast meat infused with green tea and grape seed extracts was investigated. Chicken breast meat was vacuum infused with green tea extract (3,000 ppm), grape seed extract (3,000 ppm), or their combination (at a total of 6,000 ppm), irradiated with an electron beam, and stored at 5 degrees C for 12 d. The targeted irradiation dosage was 3.0 kGy and the average absorbed dosage was 3.12 kGy. Values of TBARS and volatile compound contents of raw and cooked chicken meat were determined during the 12-d storage period. Thiobarbituric acid reactive substances values ranged from 15.5 to 71.4 mg of malondialdehyde/kg for nonirradiated raw chicken and 17.3 to 80.1 mg of malondialdehyde/kg for irradiated raw chicken. Values for cooked chicken ranged from 31.4 to 386.2 and 38.4 to 504.1 mg of malondialdehyde/kg for nonirradiated and irradiated chicken, respectively. Irradiation increased TBARS and hexanal values of controls and meat infused with plant extracts. Hexanal had the highest intensity of volatiles followed by pentanal and other volatiles. Cooking the samples significantly (P < 0.05) increased the amounts of TBARS and volatiles. Addition of plant extracts decreased the amount of TBARS as well as hexanal and pentanal values. Although irradiation increases lipid oxidation, infusion of chicken meat with plant extracts could reduce lipid oxidation caused by irradiation.

Aldehydes↗
PubMed2006

The high throughput screening of neuropeptide FF2 receptor ligands from Korean herbal plant extracts.

We have screened 356 libraries of Korean herbal plant extracts to find potential anti-obesity drugs. We employed the recently developed fluorescence polarization high throughput screening (FP HTS) assays of human neuropeptide FF (NPFF) receptors in 384-well microtiter plates. The primary hits were cherry-picked from the libraries and further analyzed by secondary displacement curve assays, in vitro GTPgammaS binding assays and cell-based CRE luciferase reporter assays. Agonists of NPFF receptors showed biphasic affinity curves while the antagonist, BIBP 3226, gave a monophasic affinity curve in competitive binding assays. We isolated and characterized two agonists of human NPFF2 receptor, PC 314 with K(i) of 1.42 microM, and PC 315 with K(i) of 2.17 microM from Schizandra chinensis. PC 314 and PC 315 have been characterized as benzoylgomisin Q (M.W. 552) and gomisin G (M.W. 536). We report that PC 314 and PC 315 are the first non-peptide, natural compounds, which bind to human NPFF2 receptors with good affinity. PC 314 and PC 315 inhibit forskolin-stimulated luciferase expression when CHO cells are co-transfected with NPFF2 receptor and CRE reporter vector. They possess the pharmacological and functional profiles of full agonists. The FP HTS system provides a specific, sensitive and reproducible methodology for studying and screening NPFF receptor ligands.

Combinatorial Chemistry Techniques↗
PubMed1985

Quantification of arabinogalactan-protein in plant extracts by single radial gel diffusion.

The amount of arabinogalactan-protein in whole plant extracts can be quantified by single radial diffusion in agarose gels containing a dye known as the beta-glucosyl-Yariv reagent which specifically interacts with and precipitates arabinogalactan-proteins. The lower limit of quantification is 0.04 microgram of arabinogalactan-protein; gum arabic is used as a standard reference arabinogalactan-protein. In principle, this method can be adapted to measure levels of any dye-precipitating macromolecule; for example, acidic polysaccharides can be estimated by their binding to the cationic dye Alcian blue.

Chemical Precipitation↗
PubMed1992

Preliminary pharmacologic evaluation of crude whole plant extracts of Elephantopus scaber. Part I: In vivo studies.

Elephantopus scaber has been used in Brazil as a traditional remedy to cause diuresis, antipyresis and to eliminate bladder stones. In the current study, aqueous and hydroalcoholic extracts of whole plants were tested for acute toxicity, analgesic, antipyretic, antiinflammatory, cardiovascular, diuretic and constipating activities. Both extracts (0.3-6 g/kg i.p.) induced writhing, loss of muscle tone, ataxia, prostration and death in mice. No analgesic effects of these extracts were detected using mouse hot-plate and acetic acid-induced writhing tests. Both extracts failed to modify diuresis or carrageenan-induced rat paw edema. In contrast, given intraperitoneally, both reduced brewer's yeast-induced hyperthermia in rats, but when given orally did not affect it. Moreover, the aqueous extract decreased the intestinal transit time in mice while the hydroalcoholic extract increased it. Finally, these extracts, given intravenously, reduced blood pressure and heart rate in rats; these effects could be blocked by atropine but not by co-administration of pyrilamine and cimetidine.

Administration, Oral↗
PubMed2004

Anti-plasmodial activity of some Kenyan medicinal plant extracts singly and in combination with chloroquine.

Sixty organic and aqueous extracts of eleven plants used for the control of malaria by local communities in Kisii District, Kenya were screened for in vitro anti-plasmodial activity. The plants selection was based on existing ethnobotanical information and interviews with local communities. The extracts were tested against chloroquine sensitive and resistant laboratory adapted strains of Plasmodium falciparum. The study revealed that 63.6% of the plants were active (IC50 < or = 100 microg/mL). Extracts of four plants, Ekebergia capensis, Stephania abyssinica, Ajuga remota and Clerodendrum myricoides gave IC50 values below 30 microg/mL against both chloroquine sensitive and resistant P. falciparum strains. Combination of extracts of E. capensis and C. myricoides with chloroquine against the multi-drug resistant P. falciparum isolate (V1/S) revealed synergistic effect. The plants which showed activity may be useful as sources for novel anti-plasmodial compounds.

Animals↗
PubMed2000

Screening of selected plant extracts for in vitro inhibitory activity on HIV-1 reverse transcriptase (HIV-1 RT).

Methanolic-aqueous extracts of 70 plants were investigated for their ability to inhibit HIV-1 reverse transcriptase activity in vitro. Two thirds of the extracts screened showed more than 50% inhibition. Two extracts inhibited the enzyme completely while four exhibited more than 90% inhibition. Tannins as nonspecific HIV-1 RT inhibitors were detected and removed from the extracts. The IC50 values of the most potent extracts after the removal of tannins for the HIV-1 RT inhibition are as follows: Sambucus racemosa 0.017 mg/ml and Geranium phaeum 0.067 mg/ml. Daunomycine was chosen as a standard substance in the non-radioactive immuno assay used for screening. As a result from the future isolation and characterization of these compounds, new leading structures are expectable.

Enzyme-Linked Immunosorbent Assay↗
PubMed1997

A scFv-alkaline phosphatase fusion protein which detects potato leafroll luteovirus in plant extracts by ELISA.

A single chain Fv antibody fragment (scFv) was obtained from a synthetic phage-antibody library after four rounds of selection against purified preparations of potato leafroll luteovirus (PLRV). Nucleotide sequence analysis showed that the scFv belongs to the human V(H)3 family. DNA encoding the scFv was sub-cloned into pDAP2 such that a scFv-alkaline phosphatase fusion protein was produced by transformed bacteria following induction by isopropyl-beta-D-thiogalactopyranoside (IPTG). The fusion protein was obtained at concentrations of 10 mg/l of Escherichia coli culture medium and these fusion protein preparations were used directly in ELISA to detect PLRV in sap extracts from infected plants. Our work is the first report of the selection of a scFv specific for a luteovirus from a synthetic phage-display library and the production of a fusion protein with alkaline phosphatase for the detection of PLRV in infected plants. The results demonstrate the potential of scFv and enzyme-scFv fusion proteins in routine testing for plant virus infection.

Alkaline Phosphatase↗
PubMed1984

Inhibition by certain plant extracts of the binding and adenylate cyclase stimulatory effect of bovine thyrotropin in human thyroid membranes.

The present studies were undertaken to explore the mechanism by which, as previous studies have shown, freeze-dried aqueous extracts (FDE) of plants of the species Lycopus virginicus and Lycopus europaeus, Melissa officinalis (Laminaceae), and Lithospermum officinale (Boraginaceae) have the ability to inhibit at least many of the effects of exogenous and endogenous TSH on the thyroid gland. To this end, we have examined the in vitro effects of FDE from these plants on the ability of bovine TSH (bTSH) to both bind to human thyroid plasma membranes (TPM) and activate adenylate cyclase therein. FDE of these four species produced a dose-related, ultimately complete, inhibition of the binding of 125I-labeled bTSH when studied at 4 C in a 20 mM Tris-HCl-0.5% BSA buffer, pH 7.45. Half-maximum inhibition of bTSH binding was produced by approximately 50 mU/ml bTSH and only about 10-30 micrograms/ml of the four active FDE. When studied in Tris-BSA-50 mM NaCl buffer at 37 C, these FDE remained inhibitory to bTSH binding, but their potency was decreased to about one fifth of that seen in the absence of NaCl. The binding of [125I]hCG to rat testis membranes was also inhibited by all of these FDE, but no effect on the binding of [125I]insulin to crude rat liver membranes was observed. In concentrations as high as 1 mg/ml, FDE of Verbena officinalis (Verbenaceae), which belongs to the same order (Tubiflorae) as the other plants, but exhibits no antithyrotropic or antigonadotropic activity in vivo, had no effect on either the binding of bTSH to thyroid membranes or the binding of hCG to rat testis membranes. No inhibition of [125I]bTSH binding occurred when TPM were preincubated with the four active FDE, washed, and then incubated with [125I]bTSH in medium devoid of FDE. Hence, the inhibition of [125I]bTSH binding seen when labeled hormone and active FDE were added together was not due to irreversible binding of FDE to TPM or damage to the TSH receptor. When [125I]bTSH was incubated with the active FDE in Tris-BSA and the mixture was chromatographed on Sephadex G-100 using the same buffer, [125I]bTSH was shifted from an apparent mol wt of 30,000 and eluted at the void volume. Direct binding of [125I]bTSH in fractions from the new, large molecular peak was nil. Addition of a large excess of unlabeled bTSH during preincubation prevented the shift in the elution pattern of [125I] bTSH produced by these FDE.(ABSTRACT TRUNCATED AT 400 WORDS)

Adenylyl Cyclases↗
PubMed2004

Larvicidal activity of plant extracts used alone and in combination with known synthetic larvicidal agents against Aedes aegypti.

Larvicidal activity of acetone and petroleum ether extracts of four plants Murraya koenigii, Coriandrum sativum, Ferula asafoetida, Trigonella foenum graceum and synthetic larvicides Fenthion and Temephos used alone and in combination was carried out against A. aegypti larvae under laboratory conditions. Optimum values were found out by using different concentrations of each plant (ranged 25 ppm-900 ppm) and both synthetic larvicides (ranged 0.01-7.5 ppm). The synergistic study was carried out by using 0.05 ppm of Temephos and Fenthion with 25ppm of M. koenigii, F. asafetida, T. foenum graceum and 100 ppm of C. sativum. All the plants showed potential synergistic activity although showed comparatively poor larvicidal activity when tested individually.

Aedes↗
PubMed2006

Larvicidal activity of some Labiatae (Lamiaceae) plant extracts from Turkey.

Ethanol extracts of the aerial parts from five Labiatae (Lamiaceae) species, obtained from Antalya, Turkey, were tested for larvicidal activity against the house mosquito Culex pipiens L. (Diptera: Culicidae) under laboratory conditions. Third and fourth instar mortality from six concentrations (5, 10, 25, 50, 100 and 200 ppm) of each plant extract were compared against the organophosphorus insecticide, temephos which is currently used for larval control. All plant extracts showed high larvicidal activity in 24 h exposure tests. Teucrium divaricatum Sieber was the most toxic, followed by Mentha longifolia (L.) Huds., Melissa officinalis L., Salvia sclarea L. and Mentha pulegium L. with LC(50) values of 18.6, 26.8, 39.1, 62.7 and 81.0 ppm, respectively. This study is the first to report on the larvicidal activity of ethanol extracts of these five plant species against C. pipiens.

Animals↗
PubMed1997

Screening for Annonaceous acetogenins in bioactive plant extracts by liquid chromatography/mass spectrometry.

The Annonaceous acetogenins are amenable to analysis by liquid chromatography/mass spectrometry (LC/MS) using the electrospray positive-ion mode. Under conditions of atmospheric pressure in-source collision-induced dissociation (APICID), the acetogenins reproducibly provided characteristic ion patterns and fragment ions. Accordingly, the presence of these biologically interesting acetogenins and other derivatives in plant extracts and chromatographic fractions can be readily detected by analyzing selected ion chromatograms. LC/MS screening of a bioactive crude methanol-soluble fraction of Rollinia mucosa detected the presence of some 40 known acetogenins in this plant extract, in addition to four new acetogenins of diverse structure. This rapid and relatively uncomplicated selected ionization procedure should also prove suitable for the screening of many other structural families of natural products.

4-Butyrolactone↗
PubMed1999

Effect on cell surface hydrophobicity and susceptibility of Helicobacter pylori to medicinal plant extracts.

Effects on aqueous extracts of medicinal plants on ten Helicobacter pylori strains were studied by the salt aggregation test to determine the possibility to modulate their cell surface hydrophobicity and by an agar diffusion assay for detection of antimicrobial activity. It was established that aqueous extracts of bearberry and cowberry leaves enhance cell aggregation of all H. pylori strains tested by the salt aggregation test, and the extract of bearberry possessed a remarkable bacteriostatic activity. Pure tannic acid showed a result similar to that of bearberry and cowberry extracts which contained a large amount of tannins. In contrast, extracts of wild camomile and pineapple-weed, which blocked aggregation of H. pylori, contained small amounts of tannins and did not reveal any antimicrobial activity. Tannic acid seems to be the component of bearberry and cowberry aqueous extracts with the highest activity to decrease cell surface hydrophobicity as well as in antibacterial activity against H. pylori.

Baltic States↗
PubMed1992

Evaluation of plant extracts for antileishmanial activity using a mechanism-based radiorespirometric microtechnique (RAM).

Extracts of eleven plants used in Nigerian traditional medicine have been evaluated for possible antileishmanial activity using a radiorespirometric microtest technique based on in vitro inhibition of catabolism of 14CO2 from a battery of 14C-substrates by promastigotes. Of 13 methanol extracts tested, 5 from Gongronema latifolia, Dorstenia multiradiata, Picralima nitida, Cola attiensis, and Desmodium gangeticum, were active at concentrations of 50 micrograms/ml or less against a visceral Leishmania isolate.

Animals↗
PubMedDate not supplied

Interaction of folk medicinal plant extracts with human alpha2-adrenoceptor subtypes.

Forty-two extracts of folk medicinal plant organs from Pakistan were tested in competition binding assays for their interaction with the specific ligand recognition sites on the human alpha2-adrenoceptor subtypes alpha2A, alpha2B and alpha2C Strong binding of the extracts (40 mg/ml) from Acacia nilotica (L.) Delile leaves (88-98% displacement of radiolabel) and Peganum harmala seeds (89-96% displacement) on three subtypes prompted us to extract these plant materials with 40% and 80% methanol, ethanol, and acetone. The extraction results indicated an absence of alpha2-adrenoceptor binding activity in the stalk of A. nilotica and A. tortils, whereas the leaves of both plants contained activity. The extracts of A. nilotica leaves showed a slight, but consistent, preference for the alpha2C-adrenoceptor, whereas the leaves of A. tortils were slightly more active on the alpha2B subtype. The extract of P. harmala stalks was less active than that of its seeds. The binding activities of A. nilotica leaves and P. harmala seeds were mainly concentrated in the water and 30% methanol fractions and further sub-fractions. In a functional activity assay, the active fractions inhibited epinephrine-stimulated 35S-GTPyS binding, thus indicating a predominantly antagonistic nature of the compounds with alpha2-adrenoceptor affinity in these fractions. Among the known major alkaloids of P. harmala (demissidine, harmaline, harmine, 6-methoxyharmalan, and norharmane), only 6-methoxyharmalan showed moderate affinity (dissociation constant (Ki) of 530 +/- 40 nm for alpha2A subtype). This study is a first systematic attempt towards the discovery of potential drug candidates from these plant materials for treating alpha2-adrenoceptor related diseases.

Binding Sites↗
PubMed1992

Inhibition of peptidase and glycosidase activities of Porphyromonas gingivalis, Bacteroides intermedius and Treponema denticola by plant extracts.

Aqueous extracts from 5 plants used widely in Kenya as chewing sticks (mswaki) for the control of oral hygiene were tested for their ability to inhibit extracellular peptidase and glycosidase enzyme activities produced by the periodontopathic bacteria Porphyromonas gingivalis (formerly Bacteroides gingivalis), Bacteroides intermedius and Treponema denticola. The plants studied were Rhus natalensis, Cupressus hisitanica, Sida cordifolia, Olea africana and Euclea divinorum. Protease activities, including glycylprolyl dipeptidase and trypsin-like activities of P. gingivalis, chymotrypsin-like and glycylprolyl dipeptidase activities of B. intermedius and the trypsin-like activity of T. denticola, were particularly affected by extracts from Rhus natalensis and Euclea divinorum. Glycosidase activities were generally less affected with the notable exceptions of the inhibition of beta-mannosidase activity of P. gingivalis by all extracts and the inhibition of neuraminidase activity of T. denticola by Rhus natalensis and Euclea divinorum. Generally, these same proteolytic and glycosidic activities were inhibited by tannic acid and to lesser extents by gallic acid and gallic acid methyl ester. An inhibitory component, present in all extracts, exhibited physical and chemical properties identical to those of tannic acid. The inhibition of these enzyme activities is likely to reduce the virulence of these periodontophathic bacteria and to reduce the rate of dental plaque formation.

Bacteroides↗