470 research outputs found
The Effect of an Aqueous Extract of Teucrium polium on Glutathione Homeostasis In Vitro: A Possible Mechanism of Its Hepatoprotectant Action
Background. Teucrium polium is used in Arab traditional medicine to treat liver diseases. Glutathione is an important intracellular antioxidant, and intrahepatic glutathione levels are depleted in liver diseases.
Hypothesis and Aim. This investigation tested the hypothesis that aqueous extracts of T. polium maintains intracellular glutathione levels by augmenting glutathione peroxidase and glutathione reductase activity in cultured hepatocytes.
Methods.
The effects of increasing concentrations (0.01–1 mg/mL) of aqueous extract of T. polium were assessed in cultured HepG2 cells following 24 hours incubation on (1) cellular integrity using (a) the Trypan blue exclusion assay, (b) the [di-methylthiazol-2yl]-2,5-diphenyl-tetrazoliumbromide (MTT) assay, and (c) the lactate dehydrogenase (LDH) assay; (2) glutathione redox state; and (3) glutathione peroxidase and glutathione reductase activities using a repeated measures experimental design.
Results. At concentrations of 0.375 mg/mL and 0.5 mg/mL, the extract increased the intracellular levels of total and reduced glutathione and had no effect on the intracellular amounts of oxidized glutathione. The extract had no effect on glutathione peroxidase and glutathione reductase activities.
Conclusion.
These data indicate that the mechanism of the hepatoprotective action of aqueous extracts of T. polium may be, in part, due to augmenting intracellular glutathione levels
Mechanical Strains Induced in Osteoblasts by Use of Point Femtosecond Laser Targeting
A study demonstrating how ultrafast laser radiation stimulates osteoblasts is presented. The study employed a custom made optical system that allowed for simultaneous confocal cell imaging and targeted femtosecond pulse laser irradiation. When femtosecond laser light was
focused onto a single cell, a rise in intracellular Ca2+ levels was observed followed by contraction of the targeted cell. This contraction
caused deformation of neighbouring cells leading to a heterogeneous strain field throughout the
monolayer. Quantification of the strain fields in the monolayer using digital image correlation revealed local
strains much higher than threshold values typically reported to stimulate extracellular bone matrix production
in vitro. This use of point targeting with femtosecond pulse lasers could provide a new method for stimulating cell
activity in orthopaedic tissue engineering
Fertilization-Induced Changes in Growth Parameters and Antioxidant Activity of Medicinal Plants Used in Traditional Arab Medicine
In response to increased popularity and greater demand for medicinal plants, a number of conservation groups are recommending that wild medicinal plants be brought into cultivation systems. We collected four medicinal herbs Cichorium pumilum, Eryngium creticum, Pistacia palaestina and Teucrium polium used in traditional Arab medicine for greenhouse cultivation to assess the effects of different fertilization regimes on their growth and antioxidant activity. Wild seedlings were collected and fertilized with either 100% Hoagland solution, 50% Hoagland solution, 20% Hoagland solution or irrigated with tap water. Plant height was measured and the number of green leaves and branches counted weekly. Thereafter, the aboveground parts of plants were harvested for preparing a water-soluble powder extracts of which antioxidant activity was measured by their ability to suppress the oxidation of β-carotene. Of the fertilization regimes, we found either 20 or 50% Hoagland solution produced the most consistent response of the plant growth parameters. All powders prepared from the four wild growing plants inhibited oxidation of β-carotene. Increasing the amount of fertilizer caused a significant concentration-dependent increase in antioxidant activity of the cultivated T. polium compared with the wild type. In contrast, increasing the amount of fertilizer caused a significant concentration-dependent reduction in the antioxidant activity of powders prepared from the cultivated E. creticum when compared with wild plants. Our results showed that cultivation success should not rely solely on parameters of growth but should incorporate assessment related to indices of therapeutic potential
Aqueous Extracts of Teucrium polium Possess Remarkable Antioxidant Activity In Vitro
Teucrium polium L. (Lamiaceae) (RDC 1117) is a medicinal plant whose species have been used for over 2000 years in traditional medicine due to its diuretic, diaphoretic, tonic, antipyretic, antispasmodic and cholagogic properties. The therapeutic benefit of medicinal plants is often attributed to their antioxidant properties. We previously reported that an aqueous extract of the leaves and stems of this plant could inhibit iron-induced lipid peroxidation in rat liver homogenate at concentrations that were not toxic to cultured hepatic cells. Others have reported that organic extracts of the aerial components of this plant could inhibit oxidative processes. Against this background, we felt further investigation on the antioxidant action of the extract of T. polium prepared according to traditional Arab medicine was warranted. Accordingly, we assessed (i) its ability to inhibit (a) oxidation of β-carotene, (b) 2,2′-azobis(2-amidinopropan) dihydrochloride (AAPH)-induced plasma oxidation and (c) iron-induced lipid peroxidation in rat liver homogenates; (ii) to scavenge the superoxide ([Formula: see text]) radical and the hydroxyl radical (OH(•)); (iii) its effects on the enzyme xanthine oxidase activity; (iv) its capacity to bind iron; and (v) its effect on cell glutathione (GSH) homeostasis in cultured Hep G2 cells. We found that the extract (i) inhibited (a) oxidation of β-carotene, (b) AAPH-induced plasma oxidation (c) Fe(2+)-induced lipid peroxidation in rat liver homogenates (IC(50) = 7 ± 2 μg ml(−1)); (ii) scavenged [Formula: see text] (IC(50) = 12 ± 3 μg ml(−1)) and OH(•) (IC(50) = 66 ± 20 μg ml(−1)); (iii) binds iron (IC(50) = 79 ± 17 μg ml(−1)); and (iv) tended to increase intracellular GSH levels resulting in a decrease in the GSSG/GSH ratio. These results demonstrate that the extract prepared from the T. polium possesses antioxidant activity in vitro. Further investigations are needed to verify whether this antioxidant effect occurs in vivo
Systematic review of the factors affecting cat and dog owner compliance with pharmaceutical treatment recommendations
© 2018 British Veterinary Association. The aim of this systematic review is to describe and assess the quality of the existing evidence base concerning factors that influence the compliance of cat and dog owners to pharmaceutical and specifically polypharmacy treatment recommendations. PubMed, CAB Abstracts and Google were searched to identify relevant literature and search results were filtered according to predetermined inclusion and exclusion criteria. Standardised data extraction and critical appraisal were carried out on each included study, and a Centre for Evidence-Based Medicine level of evidence grading was applied. Of the 8589 studies, eight studies were included in the review. Majority (five of eight) of the included studies were examining compliance with short-term antimicrobial therapies and none examined polypharmacy. Multiple definitions of compliance, methods of measurement and different factors potentially affecting compliance were used. Factors reported to have affected compliance in at least one study were dosing regimen, discussion of dosing regimen in light of owners' circumstances, consultation time, disease, month of consultation/treatment, physical risk, social risk and method of administration. The evidence available regarding factors affecting client compliance with pharmaceutical treatment recommendations in cats and dogs is scarce and of poor quality
Discrete Cylindrical Vector Beam Generation from an Array of Optical Fibers
A novel method is presented for the beam shaping of far field intensity
distributions of coherently combined fiber arrays. The fibers are arranged
uniformly on the perimeter of a circle, and the linearly polarized beams of
equal shape are superimposed such that the far field pattern represents an
effective radially polarized vector beam, or discrete cylindrical vector (DCV)
beam. The DCV beam is produced by three or more beams that each individually
have a varying polarization vector. The beams are appropriately distributed in
the near field such that the far field intensity distribution has a central
null. This result is in contrast to the situation of parallel linearly
polarized beams, where the intensity peaks on axis
Focusing of atoms with strongly confined light potentials
Focusing of atoms with light potentials is studied. In particular, we
consider strongly confined, cylindrical symmetric potential, and demonstrate
their applications in both red and blue-detuned focusing of atoms. We also
study the influence of aberrations, and find that a resolution of 1 nm should
in principle be possible.Comment: 23 pages, 9 figures, Submitted to Optics Communication
Ultra-high field enhancing in Split Ring Resonators by azimuthally polarized excitation
We study the field enhancement and resonance frequencies in split-ring
resonators (SRR) illuminated by azimuthally polarized light. We find that
compared to linearly polarized illumination, the azimuthally polarized
illumination increase the intensity enhancement by more than an order of
magnitude. We attribute the increase in the intensity enhancement to the
improved overlap between the SRR geometry and the direction of the electric
field vector in each point. In addition, we present and explore a method to
tune the resonance frequency of the SRR (for azimuthal polarization) by
introducing more gaps to the structure. This approach allows for simple and
straightforward tuning of the resonance frequency with small impact on the
intensity enhancement. The impact of the design parameters on the intensity
enhancement under azimuthally polarized illumination is also studied in
details, exhibiting clear differences to the case of linear polarized
illumination.Comment: To be published in Optics Expres
- …