319 research outputs found
Relationship between chemical composition and nematicidal activity of different essential oils
In this study, the relationship between nematicidal activity and chemical composition of ten essential oils (EOs) from different plant species was investigated both in in vitro assays on juveniles (J2) and eggs of the root-knot nematode Meloidogyne incognita and in experiments on tomato in soil infested by M. incognita. Nematode J2 were exposed for 4, 8 or 24 h to 0.78–100 µg mL−1 concentrations of each EO, whereas 24, 48 or 96 h exposures to 250, 500 and 1000 µg mL−1
solutions were tested on M. incognita egg masses. Treatments with 50, 100 or 200 µg kg soil rates of each EO were applied in the experiment on potted tomato. The highest nematicidal potential resulted for the C. verum EO, as highly toxic to both M. incognita J2 and eggs and strongly suppressive on nematode multiplication on tomato roots. The infestation of M. incognita on tomato roots was also strongly reduced by the EOs from E. citriodora and S. aromaticum, both highly toxic to M. incognita J2 but less active on nematode eggs. Adversely, R. graveolens EO strongly inhibited the egg hatch but was limitedly toxic to the
infective J2. Chemical composition of the EOs was determined by GC-FID and GC-MS. The ten EOs showed a very different chemical composition in terms of major phytochemicals, with one or two dominant components totally amounting up to 85%. The structure–activity relationship based on the main phytochemicals identified in the assayed EOs and their nematicidal effects on M. incognita was also discussed. Results from this study confirmed that the selection of suitable EO raw materials can lead to the formulation on new effective nematicidal products
Phytochemical and biological characterization of dry outer scales extract from Tropea red onion (Allium cepa L. var. Tropea)–A promising inhibitor of pancreatic lipase
Background: Allium cepa L. var. Tropea is typically cultivated in Calabria (Italy) and it is certified as “Cipolla Rossa di Tropea Calabria-PGI” (Tropea red onion). The use of clinically available anti-obesity drugs such as Orlistat is being gradually dismissed due to their side-effects and this has encouraged the search for alternative inhibitors of intestinal lipases such as phytochemicals showing less side-effects. In this study we aimed to evaluate for the first time the anti-obesity potential of the hydroalcoholic extract from the dry outer scales of Tropea red onion by the assesment of its capacity to inhibit pancreatic lipase. Its possible mechanism of action was also studied with planar lipid membranes (PLMs) surrogate of intestinal membranes. Methods: Specialized metabolites in the extract were determined by GC–MS, HPLC-DAD, HPLC-UV-DAD and HPLC-HRMS analyses. Inhibition of pancreatic lipase was studied in vitro against crude lipase Type II from porcine pancreas. PLMs used in the electrophysiology measurements were made up of DOPS:DOPE:POPC. Results: The extract contained quercetin-4′-O-glucoside, quercetin and quercetin-3,4′-O-diglucoside as the most abundant phenolics. Among apolar constituents, γ-sitosterol, linoleic and stearic acids were dominant. The lipase inhibitory effect of the extract had an IC50 value equal to 0.77±0.03 mg/mL (positive control, IC50 = 0.018 mg/mL). The electrophysiological study demonstrated that the extract is able to incorporate into PLMs and to form transient channel-like events Conclusions: Taken altogether, the results allow us to suggest that the hydroalcoholic extract from the dry outer scales of Tropea red onion could prevent lipid ester hydrolysis and it has a protective effect against phospholipase as found for interfacially active compounds
CYP72A67 catalyses a key oxidative step in Medicago truncatula hemolytic saponin biosynthesis
In the Medicago genus, triterpenic saponins are bioactive secondary metabolites constitutively synthesized
in the aerial and subterranean parts of plants via the isoprenoid pathway. Exploitation of saponins
as pharmaceutics, agrochemicals and in the food and cosmetic industries has raised interest in identifying
the enzymes involved in their synthesis. We have identified a cytochrome P450 (CYP72A67) involved in
hemolytic sapogenin biosynthesis by a reverse genetic TILLING approach in a Medicago truncatula ethylmethanesulfonate
(EMS) mutagenized collection. Genetic and biochemical analyses, mutant complementation,
and expression of the gene in a microsome yeast system showed that CYP72A67 is responsible for
hydroxylation at the C-2 position downstreamof oleanolic acid synthesis. The affinity of CYP72A67 for substrates
with different substitutions at multiple carbon positions was investigated in the same in vitro yeast
system, and in relation to two other CYP450s (CYP72A68) responsible for the production of medicagenic
acid, the main sapogenin in M. truncatula leaves and roots. Full sib mutant and wild-type plants were
compared for their sapogenin profile, expression patterns of the genes involved in sapogenin synthesis,
and response to inoculation with Sinorhizobium meliloti. The results obtained allowed us to revise the
hemolytic sapogenin pathway in M. truncatula and contribute to highlighting the tissue specificities
(leaves/roots) of sapogenin synthesis
New frontiers and emerging applications of 3D printing in ENT surgery: A systematic review of the literature
3D printing systems have revolutionised prototyping in the industrial field by lowering production time from days to hours and costs from thousands to just a few dollars. Today, 3D printers are no more confined to prototyping, but are increasingly employed in medical disci- plines with fascinating results, even in many aspects of otorhinolaryngology. All publications on ENT surgery, sourced through updated electronic databases (PubMed, MEDLINE, EMBASE) and published up to March 2017, were examined according to PRISMA guidelines. Overall, 121 studies fulfilled specific inclusion criteria and were included in our systematic review. Studies were classified according to the specific field of application (otologic, rhinologic, head and neck) and area of interest (surgical and preclinical education, customised surgical planning, tissue engineering and implantable prosthesis). Technological aspects, clinical implications and limits of 3D printing processes are discussed focusing on current benefits and future perspectives
Hypericum perforatum plant cells reduce Agrobacterium viability during co-cultivation
Plant recalcitrance is the major barrier in developing Agrobacterium-mediated transformation protocols for several important plant species. Despite the substantial knowledge of T-DNA transfer process, very little is known about the factors leading to the plant recalcitrance. Here, we analyzed the basis of Hypericum perforatum L. (HP) recalcitrance to Agrobacterium-mediated transformation using cell suspension culture. When challenged with Agrobacterium, HP cells swiftly produced an intense oxidative burst, a typical reaction of plant defense. Agrobacterium viability started to decline and reached 99% mortality within 12 h, while the plant cells did not suffer apoptotic process. This is the first evidence showing that the reduction of Agrobacterium viability during co-cultivation with recalcitrant plant cells can affect transformation
Variability in the carbon isotopic composition of foliage carbon pools (soluble carbohydrates, waxes) and respiration fluxes in southeastern U.S. pine forests
Author Posting. © American Geophysical Union, 2012. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 117 (2012): G02009, doi:10.1029/2011JG001867.We measured the δ13C of assimilated carbon (foliage organic matter (δCOM), soluble carbohydrates (δCSC), and waxes (δCW)) and respiratory carbon (foliage (δCFR), soil (δCSR) and ecosystem 13CO2 (δCER)) for two years at adjacent ecosystems in the southeastern U.S.: a regenerated 32 m tall mature Pinus palustris forest, and a mid-rotation 13 m tall Pinus elliottii stand. Carbon pools and foliage respiration in P. palustris were isotopically enriched by 2‰ relative to P. elliottii. Despite this enrichment, mean δCER values of the two sites were nearly identical. No temporal trends were apparent in δCSC, δCFR, δCSR and δCER. In contrast, δCOM and δCW at both sites declined by approximately 2‰ over the study. This appears to reflect the adjustment in the δ13C of carbon storage reserves used for biosynthesis as the trees recovered from a severe drought prior to our study. Unexpectedly, the rate of δ13C decrease in the secondary C32–36 n-alkanoic acid wax molecular cluster was twice that observed for δCOM and the predominant C22–26 compound cluster, and provides new evidence for parallel but separate wax chain elongation systems utilizing different carbon precursor pools in these species. δCFR and δCER were consistently enriched relative to assimilated carbon but, in contrast to previous studies, showed limited variations in response to changes in vapor pressure deficit (D). This limited variability in respiratory fluxes and δCSC may be due to the shallow water table as well as the deep taproots of pines, which limit fluctuations in photosynthetic discrimination arising from changes in D.This work was supported by a NSF
grants DEB-0343604, DEB-0344562 and DEB-0552202, and DOE grant
DE-FC02-06ER64156/06-SC-NICCR-1063.2012-10-1
Do bilateral social security agreements deliver on the portability of pensions and health care benefits? A summary policy paper on four migration corridors between EU and non-EU member states
Hypericum sp.: essential oil composition and biological activities
Phytochemical composition of Hypericum
genus has been investigated for many years. In the recent past, studies on the essential oils (EO) of this genus have been progressing and many of them have reported interesting biological activities. Variations in the EO composition of Hypericum species influenced
by seasonal variation, geographic distribution, phenological cycle and type of the organ in which EO are produced and/or accumulated have also been reported. Although many reviews attributed to the characterization
as well as biological activities of H. perforatum
crude extracts have been published, no review has been published on the EO composition and biological activities of Hypericum species until recently (Crockett
in Nat Prod Commun 5(9):1493–1506, 2010;
Bertoli et al. in Global Sci Books 5:29–47, 2011). In this article, we summarize and update information regarding the composition and biological activities of Hypericum species EO. Based on experimental work carried out in our laboratory we also mention possible biotechnology approaches envisaging EO improvement of some species of the genus.Fundação para a Ciência e a Tecnologia (FCT) - project PTDC/AGR AAM/70418/2006, SFRH/BD/
13283/2003
Growth Inhibition of Human Gynecologic and Colon Cancer Cells by Phyllanthus watsonii through Apoptosis Induction
Phyllanthus watsonii Airy Shaw is an endemic plant found in Peninsular Malaysia. Although there are numerous reports on the anti cancer properties of other Phyllanthus species, published information on the cytotoxicity of P. watsonii are very limited. The present study was carried out with bioassay-guided fractionation approach to evaluate the cytotoxicity and apoptosis induction capability of the P. watsonii extracts and fractions on human gynecologic (SKOV-3 and Ca Ski) and colon (HT-29) cancer cells. P. watsonii extracts exhibited strong cytotoxicity on all the cancer cells studied with IC50 values of ≤ 20.0 µg/mL. Hexane extract of P. watsonii was further subjected to bioassay-guided fractionation and yielded 10 fractions (PW-1→PW-10). PW-4→PW-8 portrayed stronger cytotoxic activity and was further subjected to bioassay-guided fractionation and resulted with 8 sub-fractions (PPWH-1→PPWH-8). PPWH-7 possessed greatest cytotoxicity (IC50 values ranged from 0.66 – 0.83 µg/mL) and was selective on the cancer cells studied. LC-MS/MS analysis of PPWH-7 revealed the presence of ellagic acid, geranic acid, glochidone, betulin, phyllanthin and sterol glucoside. Marked morphological changes, ladder-like appearance of DNA and increment in caspase-3 activity indicating apoptosis were clearly observed in both human gynecologic and colon cancer cells treated with P. watsonii especially with PPWH-7. The study also indicated that P. watsonii extracts arrested cell cycle at different growth phases in SKOV-3, Ca Ski and HT-29 cells. Cytotoxic and apoptotic potential of the endemic P. watsonii was investigated for the first time by bioassay-guided approach. These results demonstrated that P. watsonii selectively inhibits the growth of SKOV-3, Ca Ski and HT-29 cells through apoptosis induction and cell cycle modulation. Hence, P. watsonii has the potential to be further exploited for the discovery and development of new anti cancer drugs
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