Anti-Neuroinflammatory effects of the extract of Achillea fragrantissima

<p>Abstract</p> <p>Background</p> <p>The neuroinflammatory process plays a central role in the initiation and progression of neurodegenerative diseases such as Parkinson's and Alzheimer's diseases, and involves the activation of brain microglial cells. During the neuroinflammatory process, microglial cells release proinflammatory mediators such as cytokines, matrix metalloproteinases (MMP), Reactive oxygen species (ROS) and nitric oxide (NO). In the present study, extracts from 66 different desert plants were tested for their effect on lipopolysaccharide (LPS) - induced production of NO by primary microglial cells. The extract of <it>Achillea fragrantissima </it>(<it>Af</it>)<it/>, which is a desert plant that has been used for many years in traditional medicine for the treatment of various diseases, was the most efficient extract, and was further studied for additional anti-neuroinflammatory effects in these cells.</p> <p>Methods</p> <p>In the present study, the ethanolic extract prepared from <it>Af </it>was tested for its anti-inflammatory effects on lipopolysaccharide (LPS)-activated primary cultures of brain microglial cells. The levels of the proinflammatory cytokines interleukin1β (IL-1β) and tumor necrosis factor-α (TNFα) secreted by the cells were determined by reverse transcriptase-PCR and Enzyme-linked immunosorbent assay (ELISA), respectively. NO levels secreted by the activate cells were measured using Griess reagent, ROS levels were measured by 2'7'-dichlorofluorescein diacetate (DCF-DA), MMP-9 activity was measured using gel zymography, and the protein levels of the proinflammatory enzymes cyclooxygenase-2 (COX-2) and induced nitric oxide synthase (iNOS) were measured by Western blot analysis. Cell viability was assessed using Lactate dehydrogenase (LDH) activity in the media conditioned by the cells or by the crystal violet cell staining.</p> <p>Results</p> <p>We have found that out of the 66 desert plants tested, the extract of <it>Af </it>was the most efficient extract and inhibited ~70% of the NO produced by the LPS-activated microglial cells, without affecting cell viability. In addition, this extract inhibited the LPS - elicited expression of the proinflammatory mediators IL-1β, TNFα, MMP-9, COX-2 and iNOS in these cells.</p> <p>Conclusions</p> <p>Thus, phytochemicals present in the <it>Af </it>extract could be beneficial in preventing/treating neurodegenerative diseases in which neuroinflammation is part of the pathophysiology.</p

Eye-Hand Coordination: Dexterous Object Manipulation in New Gravity Fields

The stabilisation of an object manipulated with the hand depends on applying a sufficiently strong force with each finger such that sufficient friction is generated to resist the load force acting tangentially to the contact surfaces. Gravity normally provides a constant force acting on the object (depending on its weight) which is adequately taken into account by an appropriate level of grip force.Variations in inertial forces caused by the subject's own arm movements over a range of accelerations also produce synchronous changes in grip forces that rise and fall with the changes in the tangential load forces on the fingers.That is, grip force reflects an anticipatory adjustment to the fluctuations in inertial forces.The modulation of grip force in anticipation of load force implies that the nervous system has access to information concerning the object's weight, mass and the kinematics of the forthcoming movement, since changes in any of these require a different grip force.This suggests that the internal models used to predict load forces and generate appropriate grip forces are pretty good. It remains to be proved, however, whether the entire control process of grip-force compensation is based on feedforward, model-based control, or if some components of the required grip responses are generated through reflex actions. Microgravity presents a significant challenge to dexterous object manipulation for a number of reasons. Owing to all the potential deviations from the expected characteristics of the load forces, planning movement under microgravity conditions might involve a greater reliance on visual, tactile and/or memory cues to an object's mass. In addition, there might be over- gripping to reduce the consequence of an erroneous estimate of mass. Alternatively, the hand might initially be moved more slowly than normal to allow more time for feedback-based adjustments to grip force. In this regard, a series of experiments has been designed in order to study the effects of a change in gravity on the dynamics of prehension, on the kinematics of upper limb movements and on eye-hand coordination. This report describes the results of some experiments already performed and the scientific objectives of the experiments that will be carried out in the coming years