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At least 127 records · Page 7Linked to original sources
PubMed2002

Effect of outer-membrane permeabilizers on the activity of antibiotics and plant extracts against Pseudomonas aeruginosa.

Several known outer membrane permeabilizers increased susceptibility of a highly resistant pathogenic strain Pseudomonas aeruginosa to different antibiotics and plant extracts. Of all the chemicals tested, EDTA, sodium citrate and sodium hexametaphosphate (HMP) were found to be potent permeabilizers as shown by enhanced lysis of the bacteria in the presence of lysozyme. In the presence of EDTA and sodium citrate susceptibility of the strain to gentamicin and rifampicin increased markedly. The strain was resistant to vancomycin but became susceptible when grown in the presence of increasing amounts of EDTA and sodium citrate. Similar results were obtained for erythromycin when treated with sodium citrate. EDTA was found to be most potent permeabilizer in enhancing the activity of the plant extracts. Though HMP was an effective permeabilizer it had a weak or no effect on the activity of the antibiotics and plant extracts.

Anti-Bacterial Agents↗
PubMed1989

Susceptibility of two-week old Lymnaea natalensis to some plant extracts.

The molluscacidal potency of 17 Nigerian plants extracted by the unevaporated crude water (UECW) method was evaluated on two-week old Lymnaea natalensis Krauss. Five extracts were not active but extracts of Balanites aegytiaca, Blighia sapida, Boswellia dalzielii, Cissampelos mucronata, Detarium microcarpum, Kigelia africana, Opilia celtidifolia, Parkia clappertoniana, Polygonum limbatum, Pseudocedrela kotschyi, Nauclea latifolia and Securidaca longipedunculata were molluscacidal. There is potential for their future use in the integrated control of Lymnaea natalensis, as well as other snails. Mortality data for lethal concentration values for all extracts were analysed by use of probit transformation. The upper and lower fiducial limits of the LC50 (P = 0.05) were also determined.

Animals↗
PubMed2005

[Antioxidative activity of some over-the-counter plant extracts].

The recent years again saw increased interest of the public in the use of traditional natural remedies, such as plant extracts, for the treatment and prevention of diseases. This paper evaluates the antioxidative activity and content of phenolic substances of selected plant extracts from medicinal herbs, sold as dietary supplements with therapeutic effects. Using the production of 3-nitrotyrosine as the marker, the effects of extracts on the inhibition of peroxynitrite-induced nitration of tyrosine was examined, and the results were compared with the ability to extinguish the stable radical 2,2-diphenyl-1-picrylhydrazyl (DPPH). A linear correlation (r = 0.929) was found between the ability to extinguish DPPH and to inhibit tyrosine nitration. The found antioxidative activity ranged between values of 0-1702, or 0-1482 micromol of the catechine equivalent/100 ml of the extract. The total content of phenolic substances oscillated within values of 9.4-268.3 mg of the equivalent of gallic acid/100 ml of the extract. The significant linear relationship between antioxidative activities (r>0.9) and the total content of phenolic substances shows that phenolic substances are the principal group responsible for the antioxidative activity of the extracts tested.

Antioxidants↗
PubMed2000

Allergic contact dermatitis to plant extracts in patients with cosmetic dermatitis.

Cosmetic contact allergy is commonly seen in patients undergoing patch testing, with fragrance one of the most frequently implicated ingredients. Many cosmetics contain plant extracts either as a fragrance or for medicinal properties. With a vogue for natural products there is an increase in their use. We have performed a prospective study over a 2-year period looking at the prevalence of contact allergy to plants in patients diagnosed with cosmetic dermatitis. In addition, we have performed a review of the products of two popular cosmetic companies, examining product labelling and the prevalence of use of plant extracts. We suggest that patients allergic to fragrance be advised to avoid plant extracts, which are separately labelled, in their personal care products.

Adolescent↗
PubMed1993

Immunoassay of taxol and taxol-like compounds in plant extracts.

A mouse monoclonal anti-taxol antibody (69E4A8E) and a rabbit polyclonal anti-taxol antiserum were used to measure taxol levels in plant extracts in a double-blind experiment in conjunction with assays by HPLC. 69E4A8E was previously shown by ELISA to be specific for taxol with only a slight cross reaction with another bioactive compound, cephalomannine; the antiserum, on the other hand, was, by radioimmunoassay (RIA), essentially equally reactive with taxol and cephalomannine. Immunoassays of the plant extracts gave results in agreement with that found by HPLC, suggesting that the antibodies can be used in simple routine procedures for the quantification of taxol or taxol-like compounds in extracts of plants or other potential natural sources.

Animals↗
PubMedDate not supplied

Oral administration of pectin-rich plant extract enhances C3 and C4 complement concentration in woman colostrum.

C3 and C4 components of the complement are normally present in human colostrum. These compounds are natural antibacterial agents. Pectin-rich plant extracts have been shown to induce prolactin release and milk synthesis when administered by the oral route in rat. In the present work, extract from a plant rich in pectin, Gossypium herbaceum was given orally to women 2 days after parturition. The extract enhanced concentration of C3 and C4 in colostrum but did not modify the total hemolytic complement activity (TCH50). No change in the concentration of the three compounds was observed in serum of the treated women. Control experiments showed that a treatment by placebo had no effect on colostrum composition. These data suggest that pectin-rich plant extracts favour transfer of C3 and C4 from blood to colostrum by an unknown mechanism. This observation suggests that some plant extracts might be used to reinforce the antibacterial activity of human colostrum.

Adult↗
PubMedDate not supplied

[In vitro effect against Giardia of 14 plant extracts].

OBJECTIVE: To investigate antigiardiasic activity in plants used in Mexico as antidiarrheics and/or antiparasitics. MATERIALS AND METHODS: Fourteen species were evaluated. The antigiardiasic activity was measured in vitro in a blinded fashion using trophozoites of Giardia duodenalis incubated with plant extracts. The viability of trophozoites was ascertained using MTT (3-[4,5-dimethylthiazol-2-il]-2, 5-diphenyl tetrazolium bromide) which is reduced to MTT-formazan by the activity of live trophozoites. The reduced MTT was extracted with an acidified alcohol (2-propanol with HCI 0.04 M) and measured in a spectrophotometer at 570 nm. Negative (trophozoites without extract) and positive controls (incubated with tinadazol) were included. RESULTS: The scientific and trivial names of the plants are given (trivials in Spanish marked by an asterisk). They had the following trophozoite mortality (mean +/- SD in percent): Justicia spicigera (muicle*) = 91 +/- 0.5; Lipia beriandieri (oregano) = 90 +/- 0.6; Psidium guajava (guava) = 87 +/- 1.0; positive control of tinidazol = 79 +/- 1.9; Punica granutus (granado*) = 78 +/- 1.3; Magnifera indica (mango) = 77 +/- 1.0; Plantago major (lante*) = 76 +/- 1.2; Cupressus semperbirens (cipres) = 73 +/- 1.2; Castella tormentosa (chaparro amargoso*) = 70 +/- 0.7; Hematoxilon campechanum (palo de Campeche*) = 67 +/- 1.2. Without or with a low mean activity were Prosopis juliflora (mesquite*) and Rizophora mangle (mangle*) with 0%, Oriza sativa (rice) with 5%, Capsicum annum (pimiento*) with 21% and Persea americana (avocado) with 23%. There were no associations of the antigiardiasic effect with concentration or osmolality of the extracts. CONCLUSIONS: A clear in vitro antigiardiasic effects was seen in nine species. Three of them were superior to tinidazol which is a drug of common use in the treatment of giardiasis.

Animals↗
PubMed2005

Protective effect of plant extract from Onobrychis ebenoides on ovariectomy-induced bone loss in rats.

OBJECTIVE: Certain plant extracts have been the object of recent studies due to their mild estrogenic action and their possible potential role in osteoporosis prevention and/or treatment. The present study was undertaken to investigate the possible protective effect of the aqueous solution of the plant Onobrychis ebenoides, with proven in vitro mild estrogenic action, on bone mass loss of the ovariectomized (Ovx) rat experimental model of osteoporosis. METHODS: Forty intact female mature (10-month-old) Wistar rats were separated into three groups: Ovx, Ovx plus plant extract (Ph) and sham-operated (control). Ph administration in the drinking water at a dose of 300 mg/kg body weight/day commenced immediately after Ovx. Bone mineral density (BMD) values, percentage change from the baseline measurement and histomorphometry of the tibia, as well as body and uterine weight, were examined and compared between groups. RESULTS: Comparison of BMD absolute values of the whole tibia of Ovx + Ph and Ovx animals at both 3 and 6 months post-Ovx were highly significant (p < 0.0005), showing a protective effect on treated animals. The extract did not appear to have such a beneficial effect on BMD of the proximal tibia of the treated animals compared to the Ovx animals after 3 months; however, a significant protective effect was observed at 6 months post-Ovx in treated animals compared to the Ovx (p = 0.015). When the % changes from baseline measurement of the whole tibia of Ovx + Ph and controls were compared, there was no significant difference at 3 or 6 months, demonstrating a highly protective effect; the respective comparisons of proximal tibia % changes did not display such protection. Body and uterine weight comparisons showed no significant difference between Ovx and treated rats, whereas, the level of significance for each group compared to controls was p < 0.0005. CONCLUSIONS: The Ph studied showed a highly significant protective effect on BMD of the whole tibia of Ovx rats after 3 and 6 months of treatment, compared to the non-treated animals. Its effect on the proximal tibia was less pronounced, but also statistically significant compared to non-treated rats after 6 months. The lack of significant effect on body and uterine weight is in favor of its selective estrogen receptor modulator-like activity, and merits further studies.

Absorptiometry, Photon↗
PubMedDate not supplied

High-performance liquid chromatography-coordination ion spray-mass spectrometry (HPLC-CIS/MS): a new tool for the analysis of non-polar compound classes in plant extracts using the example of Piper methysticum Forst.

An efficient method to characterise complex plant extracts is described using the example of Piper methysticum Forst. (kava; Piperaceae). The method is based on the on-line coupling of high-performance liquid chromatography to a new detection technique: coordination ion spray-mass spectrometry (CIS/MS). CIS/MS is a universal, novel ionisation technique improving selectivity as well as sensitivity. Charged complexes were formed through addition of central complexing ions such as sodium, silver and cobalt. The advantages of CIS/MS detection compared with the electrospray ionisation detection are discussed. The experimental set-up and the application of this simple and robust technique is described to show the its various fields of application in the analysis of plant extracts.

Chromatography, High Pressure Liquid↗
PubMed2003

Determination of peroxyl radical scavenging activity of flavonoids and plant extracts using an automatic potentiometric titrator.

A novel potentiometric method for evaluation of peroxyl radical scavenging activity of flavonoids and plant extracts was developed. The oxidation of potassium iodide (KI) was performed in acetonitrilephosphate buffer (1:1) containing antioxidant using 2,2'-azobis(2-amidinopropane) dihydrochloride as a peroxyl radical generator. The amount of iodine released from KI during a 20-min free radical oxidation was determined quantitatively using an automatic potentiometric titrator with sodium thiosulfate. The radical scavenging activity of the sample was expressed as the inhibition ratio for iodine release of the control group mediated by the radical. The results obtained from some authentic polyphenols correlated well with those of previous reports. This is a simple, time-saving method requiring less than 30 min and is useful in assessing the radical scavenging activity of antioxidants in plant extracts. We describe the radical scavenging activities of various flavonoids including 21 kinds of tea catechins and vegetable extracts by this method.

Camellia sinensis↗
PubMed1996

Antimicrobial activity of some medicinal plants extracts on Escherichia coli, Salmonella paratyphi and Shigella dysenteriae.

The antimicrobial activity of three plants extracts--Momordica charantia, Alstonia boonei, and Ocimum bacilicum on pure and viable cultures of Escherichia coli, Salmonella paratyphi and Shigella dysenterae was examined. Cold maceration method of extraction using 95% ethanol was used for the extraction of the active constituents of the leaves. Filter paper disks which were 6 mm in diameter were used for sensitivity testing. Results showed that the extracts from the leaves of the three plants have some antimicrobial properties against the test organisms which suggest their future possible commercial therapeutic use, although this is a preliminary study.

Anti-Bacterial Agents↗
PubMed1989

[Anti-inflammatory, analgesic and antipyretic effect of various plant extracts and their combinations in an animal model].

Antiinflammatory, Analgesic and Antipyretic Effects of Various Plant Extracts and a Combination Thereof in Animal Models. The three main components comprising the efficacy of non-steroidal antiinflammatory drugs could be demonstrated for STW 1 in different animal models. The phytotherapeutic preparation, containing three individual plant extracts (Populus tremula, Solidago virgaurea, Fraxinus excelsior) produced dose-dependent antiinflammatory, analgesic and antipyretic effects which were similar to those of the reference substances salicyl alcohol and indometacin. As each of the individual extracts displayed considerable efficacy, it may be assumed that each of them contributes to the overall effects of the combination STW 1.

Animals↗
PubMed2002

Taste thresholds and suprathreshold responses to tannin-rich plant extracts and quinine in a primate species (Microcebus murinus).

Theories of plant chemical defenses discriminate between quantitative digestibility reducers (e.g., tannins) and qualitative toxins (e.g., alkaloids). Since the differential effect on taste of these compounds is poorly known, we recorded ingestive responses of a primate species, Microcebus murinus, to four tannin-rich plant extracts and to quinine, by using the behavioral method of the "two-bottle test." The efficiency of tannic extracts at precipitating protein was measured with the blue BSA method. Inhibition taste thresholds for tannins added to a moderately sweet solution varied between 0.25 and 2 g/l. The threshold for quinine hydrochloride was 0.32 g/l. The profiles of the response/concentration curves established for these astringent and bitter substances were similar, with maximal inhibition of consumption occurring for near-threshold concentrations. The large amounts of quinine required to deter this small-bodied species from feeding were unexpected, given its unspecialized frugivorous/insectivorous diet. We propose that the taste responses of Microcebus to tannins have been shaped in relation to the widespread occurrence of efficient polyphenols in food plants, while low responsiveness to quinine reflects a low risk of ingesting toxic alkaloids when feeding on ripe fruits and insects.

Animals↗
PubMed1998

The Griess assay: suitable for a bio-guided fractionation of anti-inflammatory plant extracts?

In the field of inflammation research the inducible nitric oxide synthase (iNOS) became an important pharmacological target, since overproduction of nitric oxide (NO) after induction of this enzyme seems to be associated with numerous pathological conditions. NO released from cells can be detected and quantified photometrically as its stable product nitrite by a simple colorimetric reaction (Griess reaction). The aim of our study was to investigate whether this method might be suitable for the bio-guided fractionation of anti-inflammatory plant extracts. For this purpose we assayed extracts as well as fractions of the roots of Curcuma zanthorrhiza Roxb, which contain the known iNOS inhibitor curcumin, and compared the obtained activity with their curcumin content. Furthermore, leaf extracts of Betula pendula Roth, to which defined amounts of curcumin were added, were examined to clarify the question whether chlorophyll might interfere with the test system. The presented results suggest that the Griess assay is indeed suitable to guide fractionation of plant extracts in order to isolate highly active compounds. Factors, however, which might restrict the broad application of this assay are the limited selection of solvents which do not interfere with the system and high contents of chlorophyll in plant extracts.

Animals↗
PubMed1999

Antimicrobial activity of essential oils and other plant extracts.

The antimicrobial activity of plant oils and extracts has been recognized for many years. However, few investigations have compared large numbers of oils and extracts using methods that are directly comparable. In the present study, 52 plant oils and extracts were investigated for activity against Acinetobacter baumanii, Aeromonas veronii biogroup sobria, Candida albicans, Enterococcus faecalis, Escherichia col, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella enterica subsp. enterica serotype typhimurium, Serratia marcescens and Staphylococcus aureus, using an agar dilution method. Lemongrass, oregano and bay inhibited all organisms at concentrations of < or = 2.0% (v/v). Six oils did not inhibit any organisms at the highest concentration, which was 2.0% (v/v) oil for apricot kernel, evening primrose, macadamia, pumpkin, sage and sweet almond. Variable activity was recorded for the remaining oils. Twenty of the plant oils and extracts were investigated, using a broth microdilution method, for activity against C. albicans, Staph. aureus and E. coli. The lowest minimum inhibitory concentrations were 0.03% (v/v) thyme oil against C. albicans and E. coli and 0.008% (v/v) vetiver oil against Staph. aureus. These results support the notion that plant essential oils and extracts may have a role as pharmaceuticals and preservatives.

Anti-Bacterial Agents↗