Passiflora incarnata attenuation of neuropathic allodynia and vulvodynia apropos GABA-ergic and opioidergic antinociceptive and behavioural mechanisms

Background: Passiflora incarnata is widely used as an anxiolytic and sedative due to its putative GABAergic properties. Passiflora incarnata L. methanolic extract (PI-ME) was evaluated in an animal model of streptozotocininduced diabetic neuropathic allodynia and vulvodynia in rats along with antinociceptive, anxiolytic and sedative activities in mice in order to examine possible underlying mechanisms. Methods: PI-ME was tested preliminary for qualitative phytochemical analysis and then quantitatively by proximate and GC-MS analysis. The antinociceptive property was evaluated using the abdominal constriction assay and hot plate test. The anxiolytic activity was performed in a stair case model and sedative activity in an open field test. The antagonistic activities were evaluated using naloxone and/or pentylenetetrazole (PTZ). PI-ME was evaluated for prospective anti-allodynic and anti-vulvodynic properties in a rat model of streptozotocin induced neuropathic pain using the static and dynamic testing paradigms of mechanical allodynia and vulvodynia. Results: GC-MS analysis revealed that PI-ME contained predominant quantities of oleamide (9-octadecenamide), palmitic acid (hexadecanoic acid) and 3-hydroxy-dodecanoic acid, among other active constituents. In the abdominal constriction assay and hot plate test, PI-ME produced dose dependant, naloxone and pentylenetetrazole reversible antinociception suggesting an involvement of opioidergic and GABAergic mechanisms. In the stair case test, PI-ME at 200 mg/kg increased the number of steps climbed while at 600 mg/kg a significant decrease was observed. The rearing incidence was diminished by PI-ME at all tested doses and in the open field test, PI-ME decreased locomotor activity to an extent that was analagous to diazepam. The effects of PI-ME were antagonized by PTZ in both the staircase and open field tests implicating GABAergic mechanisms in its anxiolytic and sedative activities. In the streptozotocin-induced neuropathic nociceptive model, PI-ME (200 and 300 mg/kg) exhibited static and dynamic anti-allodynic effects exemplified by an increase in paw withdrawal threshold and paw withdrawal latency. PI-ME relieved only the dynamic component of vulvodynia by increasing flinching response latency. Conclusions: These findings suggest that Passiflora incarnata might be useful for treating neuropathic pain. The antinociceptive and behavioural findings inferring that its activity may stem from underlying opioidergic and GABAergic mechanisms though a potential oleamide-sourced cannabimimetic involvement is also discussed

Porosity determination of self-compacting concretes using combined forced saturation

The superplasticizers (SP) and high mineral addition contents used in Self-Compacting Concrete (SCC) can have an important effect on the porosity of the hardened mixtures, influencing their durability and mechanical strength. In this paper, a combination of forced vacuum and boiling saturation techniques is used to determine the influence of the composition of six SCC concrete mixtures on the open porosity. The mixtures differ by the type of addition (quartzite, fly ash and two types of limestone addition), the cement type (a CEM I 52.5 R HES Portland cement and a coarser CEM III/A 42.5 N LA blast furnace slag (BFS) cement) and the cement-to-powder ratio (C/P). A traditionally vibrated concrete (TC) mixture with an identical water-to-cement ratio (W/C) is tested as a reference. The tests are performed on one year old concrete core samples. The combination of the saturation techniques results in an improved, though somewhat lengthy open porosity determination. The results show a distinct influence of the addition type: a higher specific volume and Blaine fineness of the addition lead to significantly lower open porosities. This effect is most important for the fly ash addition, for which the pozzolanic reaction adds to the densification of the microstructure. Due to the old age of the samples, the expected higher porosity for the coarser BFS cement is not distinguishable: the secondary pozzolanic reaction has had the time to phase out any differences. The lower C/P logically yields higher porosities due to the smaller quantities of reactive materials and consequent higher W/C. Except for the latter, all SCC mixtures show reduced open porosities compared to the TC, which can be explained by the presence of the additions and the superplasticizer

A compilation of charged-particle induced thermonuclear reaction rates

Low-energy cross section data for 86 charged-particle induced reactions involving light (1 ≤ Ζ ≤ 14), mostly stable, nuclei are compiled. The corresponding Maxwellian-averaged thermonuclear reaction rates of relevance in astrophysical plasmas at temperatures in the range from 106 Κ to 1010 Κ are calculated. These evaluations assume either that the target nuclei are in their ground state, or that the target states are thermally populated following a Maxwell-Boltzmann distribution, except in some cases involving isomeric states. Adopted values complemented with lower and upper limits of the rates are presented in tabular form. Analytical approximations to the adopted rates, as well as to the inverse/direct rate ratios, are provided. © 1999 Elsevier Science B.V. All rights reserved.info:eu-repo/semantics/publishe