Xanthomicrol Activity in Cancer HeLa Cells: Comparison with Other Natural Methoxylated Flavones

The methoxylated flavone xanthomicrol represents an uncommon active phenolic compound identified in herbs/plants with a long application in traditional medicine. It was isolated from a sample of Achillea erba-rotta subsp. moschata (musk yar-row) flowering tops. Xanthomicrol promising biological properties include antioxidant, anti-inflammatory, antimicrobial, and anticancer activities. This study mainly focused on the evaluation of the xanthomicrol impact on lipid metabolism in cancer HeLa cells, together with the investigation of the treatment-induced changes in cell growth, morphology, and apoptosis. At the dose range of 5–100 μM, xanthomicrol (24 h of incubation) significantly reduced viability and modulated lipid profile in cancer Hela cells. It induced marked changes in the phospholipid/cholesterol ratio, significant decreases in the levels of oleic and palmitic acids, and a marked increase of stearic acid, involving an inhibitory effect on de novo lipogenesis and desaturation in cancer cells. Moreover, marked cell morphological alterations, signs of apoptosis, and cell cycle arrest at the G2/M phase were observed in cancer treated cells. The bioactivity profile of xanthomicrol was compared to that of the anticancer methoxylated flavones eupatilin and artemetin, and structure–activity relationships were underlined

Role of the trigeminal mesencephalic nucleus in rat whisker pad proprioception

Abstract Background Trigeminal proprioception related to rodent macrovibrissae movements is believed to involve skin receptors on the whisker pad because pad muscles operate without muscle spindles. This study was aimed to investigate in rats whether the trigeminal mesencephalic nucleus (TMnu), which provides proprioceptive feedback for chewing muscles, may be also involved in whisker pad proprioception. Methods Two retrograde tracers, Dil and True Blue Chloride, were injected into the mystacial pad and the masseter muscle on the same side of deeply anesthetized rats to label the respective projecting sensory neurons. This double-labeling technique was used to assess the co-innervation of both structures by the trigeminal mesencephalic nucleus (TMnu). In a separate group of anesthetized animals, the spontaneous electrical activities of TMnu neurons were analyzed by extracellular recordings during spontaneous movements of the macrovibrissae. Mesencephalic neurons (TMne) were previously identified by their responses to masseter muscle stretching. Changes in TMne spontaneous electrical activities, analyzed under baseline conditions and during whisking movements, were statistically evaluated using Student's t-test for paired observations. Results Neuroanatomical experiments revealed different subpopulations of trigeminal mesencephalic neurons: i) those innervating the neuromuscular spindles of the masseter muscle, ii) those innervating the mystacial pad, and iii) those innervating both structures. Extracellular recordings made during spontaneous movements of the macrovibrisae showed that whisking neurons similar to those observed in the trigeminal ganglion were located in the TMnu. These neurons had different patterns of activation, which were dependent on the type of spontaneous macrovibrissae movement. In particular, their spiking activity tonically increased during fan-like movements of the vibrissae and showed phasic bursting during rhythmic whisking. Furthermore, the same neurons may also respond to masseter muscle stretch. Conclusions results strongly support the hypothesis that the TMnu also contains first-order neurons specialized for relaying spatial information related to whisker movement and location to trigeminal-cortical pathways. In fact, the TMnu projects to second-order trigeminal neurons, thus allowing the rat brain to deduce higher-order information regarding executed movements of the vibrissae by combining touch information carried by trigeminal ganglion neurons with proprioceptive information carried by mesencephalic neurons.</p

Butyrylcholinesterase Inhibitors: Structure-Activity Relationships of 2-Phenylbenzofuran derivatives.

Butyrylcholinesterase Inhibitors: Structure-Activity Relationships of 2-Phenylbenzofuran derivatives Antonella Fais1*, Giovanna L. Delogu 1, Benedetta Era 1, Amalia Di Petrillo1, Amit Kumar2,3, Paola Caria4, Sonia Floris1, Francesca Pintus1 1Department of Life and Environmental Sciences, University of Cagliari , Cagliari , Italy; 2Department of Mech., Chem. and Material Engineering , University of Cagliari , Cagliari , Italy; 3Biosciences Sector, CRS4 ,Pula , Italy 4Department of Biomedical Sciences, University of Cagliari, Cagliari, Italy *Corresponding author: [email protected] Alzheimer’s disease (AD) is an irreversible and progressive brain disorder which is characterized by progressive memory loss and a wide range of cognitive impairments.1 Although the precise cause of AD is not completely known, there are some factors that seem to play a significant role in the pathogenesis of AD. Since AD is characterized by a forebrain cholinergic neuron loss and a progressive decline in acetylcholine, a possible therapeutic strategy involves the use of cholinesterase (ChE) inhibitors to restore the neurotransmitter level and thus alleviate AD symptoms.2 Benzofuran scaffold has drawn considerable attention over the last few years due to its profound physiological and chemotherapeutic properties. Recent studies have also investigated their inhibitory activity towards ChEs.3,4 In this study, a series of 2-phenylbezonfurans compounds were synthesized and their inhibition activity towards the ChE enzymes were investigated. We further combined biochemical analysis and molecular modelling studies to identify selective butyrylcholinesterase (BChE) inhibition by benzofuran scaffold. In particular, two compounds exhibited the highest BChE inhibition with IC50 values better than the standard cholinesterase inhibitor compound. Molecular modelling studies highlighted the importance of catalytic and peripheral site residues in BChE inhibition. Subsequently, the biosafety of the two promising compounds was evaluated, in NSC-34 cells at the concentration in which BChE activity is inhibited, and no considerable cytotoxic effect was found. References 1. Schuster et al. Bioorg. Med. Chem. (2010) 18, 5071. 2. Zemek et al. Expert Opin Drug Saf (2014) 13, 759. 3. Mostofi et al. Eur. J. Med. Chem. (2015) 103, 361. 4. Delogu et al. Bioorg. Med. Chem. (2016) 26, 2308

Olfactory-hypoglossal connections

Natural olfactory stimulation with amyl acetate significantly modulates the electrical activity of hypoglossal neurons and the electromyographic responses of the tongue musculature. The aim of the present study was to identify and characterize, using neuroanatomical and neurophysiological approaches, the pathways involved in the transmission of the olfactory information to the hypoglossal nucleus (XIIn). The neuroanatomical findings provided the initial demonstration that olfactory information is conveyed from the olfactory bulb to the hypoglossal nucleus via the interpeduncular nucleus (IPn) by both fast disynaptic and different polysynaptic pathways. The latter, in particular, involve many of the brain structures that process olfactory information. The electrophysiological studies demonstrated that the IPn neurons respond with a variety of patterns to natural stimulation of the olfactory receptors, thus supporting the hypothesis that the IPn is a crucial relay station for the elaboration and transmission of olfactory stimuli to XIIn

Involvement of trigeminal mesencephalic nucleus in kinetic encoding of whisker movements

In previous experiments performed on anaesthetised rats, we demonstrated that whisking neurons responsive to spontaneous movement of the macrovibrissae are located within the trigeminal mesencephalic nucleus (Me5) and that retrograde tracers injected into the mystacial pad of the rat muzzle extensively labelled a number of Me5 neurons. In order to evaluate the electrophysiological characteristics of the Me5–whisker pad neural connection, the present study analysed the Me5 neurons responses to artificial whisking induced by electrical stimulation of the peripheral stump of the facial nerve. Furthermore, an anterograde tracer was injected into the Me5 to identify and localise the peripheral terminals of these neurons in the mystacial structures. The electrophysiological data demonstrated that artificial whisking induced Me5 evoked potentials as well as single and multiunit Me5 neurons responses consistent with a direct connection. Furthermore, the neuroanatomical findings showed that the peripheral terminals of the Me5 stained neurons established direct connections with the upper part of the macrovibrissae, at the conical body level, with fibres spiralling around the circumference of the vibrissae shaft. As for the functional role of this sensory innervation, we speculated that the Me5 neurons are possibly involved in encoding and relaying proprioceptive information related to vibrissae movements to other CNS structures

Hypoglossal nuclei participation in rat mystacial pad control

Recently, we showed that extra-trigeminal axons, originating from the hypoglossal nucleus, travel with the infraorbital division of the trigeminal nerve (ION), which is known to innervate the rat mystacial pad. Dil was monolaterally injected into the rat XII nucleus to analyse the peripheral distribution of hypoglossal axons to the mystacial pad, to evaluate their involvement in facial sensory–motor control. Electromyographic responses of mystacial pad motor units to electrical stimulation of the ION were recorded, along with the evoked responses to electrical stimulation of the ipsilateral XII nucleus. The results showed that hypoglossal axon terminals target the ipsilateral extrinsic musculature of the mystacial pad, but they do not have any contact with the intrinsic muscles. ION electrical stimulation increased electromyographic activity in the ipsilateral pad extrinsic muscles, even following VII nerve transection. Hypoglossal nucleus electrical stimulation induced field potentials and monosynaptic responses in the same motor units that persisted even following VII nerve transection, these disappearing after cooling the ION. We suggest that the small hypoglossal neurons projecting to the extrinsic musculature of the mystacial pad are part of a hypoglossal–trigeminal loop that participates in the sensory–motor control of the rat vibrissae system