Calidad nutricional y contenido fitoquímico de aceites prensados en frío de semillas de chía, cardo mariano, nigella, y amapola blanca y negra

Cold pressed oils obtained from chia (Salvia hispanica L.), milk thistle (Silybum marianum L.), nigella (Nigella sativa L.), and white and black varieties of poppy (Papaver somniferum L.) seeds were character­ized. The nutritional quality was determined based on the analysis of fatty acids, tocochromanol and phytos­terol contents, as well as antioxidant activity and general physico-chemical properties. Among the oils analyzed the fatty acid composition most beneficial for health was found in chia seed oil, with 65.62% of α-linolenic acid and the n-6:n-3 fatty acid ratio of 1:3.5. Other oils studied were rich sources of linoleic acid (18.35-74.70%). Chia seed oil was also distinguished by high contents of phytosterols, mainly β-sitosterol (2160.17 mg/kg oil). The highest content of tocochromanols was found in milk thistle oil with dominant α-tocopherol (530.2 mg/kg oil). In contrast, the highest antioxidant activity was recorded for nigella oil (10.23 μM Trolox/g), which indi­cated that, in addition to tocopherols, other antioxidants influenced its antioxidant potential.Se caracterizaron aceites prensados en frío obtenidos de semillas de chía (Salvia hispanica L.), cardo mariano (Silybum marianum L.), nigella (Nigella sativa L.) y de variedades blancas y negras de amapola (Papaver somniferum L.). La calidad nutricional se determinó en base al análisis de ácidos grasos, el contenido de tococromanoles y fitosteroles, así como la actividad antioxidante y las propie­dades fisicoquímicas generales. Entre los aceites analizados, la composición de ácidos grasos más beneficiosa para la salud se encontró en el aceite de semilla de chía, con un 65,62% de ácido α-linolénico y una relación de ácido graso n-6:n-3 de 1:3,5. Los demás aceites estudiados fueron ricos en ácido linoleico (18,35-74,70%). El aceite de semilla de chía también se distinguió por el alto contenido de fitosteroles, principalmente β-sitosterol (2160,17 mg/kg de aceite). El mayor contenido de tococromanoles se encontró en el aceite de cardo mariano con α-tocoferol dominante (530,2 mg/kg de aceite). Por el contrario, se registró la mayor actividad antioxidante para el aceite de nigella (10,23 μM Trolox/g), lo que indica que, además del tocoferol, otros antioxidantes influyeron en su potencial antioxidante

Cromatografía en columna como método para la eliminación de componentes menores del aceite de colza

The purpose of this study was to verify the influence of different chromatographic column beds (silicic acid, activated charcoal, aluminum oxide, silica gel) on the concentration of individual minor components (sterols, tocopherols, carotenoids and chlorophyll) in rapeseed oil. With the use of a combination of these beds, a three-stage optimized method for removing minor components from rapeseed oil was developed. It was demonstrated that the combination of silicic acid and activated charcoal removed about half of the sterols present from the oil. Aluminum oxide turned out to be the most effective bed in removing tocopherols, purifying the oil to their minimum level (2.6 mg/kg). All adsorbents used had similar capacity to purify oil from pigments (carotenoids and chlorophyll). In the three-stage purification process free sterols were almost completely removed (to the level 90.0 mg/kg). Purification of β-carotene and chlorophyll from the oil was also very effective. Tocopherols were completely removed with this method, except for a small amount of α-tocopherol (0.4 mg/kg), which results from its relatively weak interaction with a hydrophilic bed. The developed method may be used in studies on the effect of association colloids on bulk oil autoxidation processes.El propósito de este estudio fue verificar la influencia de diferentes rellenos de columnas cromatográficas (ácido silícico, carbón activo, óxido de aluminio, gel de sílice) sobre la concentración de componentes menores individuales (esteroles, tocoferoles, carotenoides y clorofila) en aceite de colza. Gracias a esto, se desarrolló un método optimizado de tres etapas para eliminar los componentes secundarios del aceite de colza (utilizando una combinación de todos los rellenos descritos anteriormente). Se ha demostrado que con la combinación de ácido silícico y carbón activo se elimina del aceite alrededor de la mitad de los esteroles presentes. El óxido de aluminio resultó ser el relleno más eficaz para eliminar los tocoferoles, purificando el aceite hasta su nivel mínimo (2,6 mg/kg). Todos los adsorbentes utilizados tenían una capacidad similar para purificar el aceite de pigmentos (carotenoides y clorofila). En el proceso de purificación en tres etapas, los esteroles libres se eliminaron casi por completo (hasta el nivel de 90,0 mg/kg). La purificación de aceite de β-caroteno y clorofila también fue muy efectiva. En este método, los tocoferoles se eliminaron completamente, excepto pequeñas cantidades de α-tocoferol (0,4 mg/kg), lo que resulta de su interacción relativamente débil con un relleno hidrófilo. El método desarrollado se puede usar en los estudios sobre el efecto de los coloides de asociación en los procesos de autooxidación de aceites a granel

Effect of Levodopa on Reward and Impulsivity in a Rat Model of Parkinson's Disease

The use of dopamine replacement therapies (DRT) in the treatment of Parkinson's disease (PD) can lead to the development of dopamine dysregulation syndrome (DDS) and impulse control disorders (ICD), behavioral disturbances characterized by compulsive DRT self-medication and development of impulsive behaviors. However, the mechanisms behind these disturbances are poorly understood. In animal models of PD, the assessment of the rewarding properties of levodopa (LD), one of the most common drugs used in PD, has produced conflicting results, and its ability to promote increased impulsivity is still understudied. Moreover, it is unclear whether acute and chronic LD therapy differently affects reward and impulsivity. In this study we aimed at assessing, in an animal model of PD with bilateral mesostriatal and mesocorticolimbic degeneration, the behavioral effects of LD therapy regarding reward and impulsivity. Animals with either sham or 6-hydroxydopamine (6-OHDA)-induced bilateral lesions in the substantia nigra pars compacta (SNc) and ventral tegmental area (VTA) were exposed to acute and chronic LD treatment. We used the conditioned place preference (CPP) paradigm to evaluate the rewarding effects of LD, whereas impulsive behavior was measured with the variable delay-to-signal (VDS) task. Correlation analyses between behavioral measurements of reward or impulsivity and lesion extent in SNc/VTA were performed to pinpoint possible anatomical links of LD-induced behavioral changes. We show that LD, particularly when administered chronically, caused the development of impulsive-like behaviors in 6-OHDA-lesioned animals in the VDS. However, neither acute or chronic LD administration had rewarding effects in 6-OHDA-lesioned animals in the CPP. Our results show that in a bilateral rat model of PD, LD leads to the development of impulsive behaviors, strengthening the association between DRT and DDS/ICD in PD.Portuguese Foundation for Science and Technology: Ciência 2007 Program and IF Development Grant (IF/00111/2013) to AJS, Portuguese Foundation for Science and Technology PhD scholarships attributed to MMC (SFRH/BD/51061/2010), FLC (SFRH/BD/47311/2008) and CS-C (SFRH/BD/51992/2012), and Post-Doctoral Fellowship to HL-A (SFRH/BPD/80118/2011). Neurochemical analysis was funded from ELKE/UOA: 11650. This article has been developed under the scope of the project NORTE-01-0145-FEDER-000013 and NORTE-01-0145-FEDER-000023, supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER). This work has been funded by FEDER funds, through the Competitiveness Factors Operational Programme (COMPETE), and by National funds, through the Foundation for Science and Technology (FCT), under the scope of the project POCI-01-0145-FEDER-007038info:eu-repo/semantics/publishedVersio

Influence of Pramipexole on Probability Discounting and Ventral Pallidal Function: Assessments in Parkinsonian-Like Rats

People with neuropathologies who are treated with dopamine agonists may be at risk to develop impulse control disorders. The overall goal of this dissertation project was to expand our knowledge on the neuropsychopharmacology of dopamine agonist-induced impulsivity. At the time this dissertation was being developed, pramipexole was the drug, gambling was the behavior, and Parkinson\u27s disease (PD) was the pathology most widely reported for this phenomenon. Therefore, we first developed a behavioral paradigm (i.e., probability discounting) to measure risk-taking, one aspect of gambling. Utilizing this paradigm, we determine if risk-taking was altered after acute and/or chronic pramipexole treatment. We incorporated an animal model of PD in this study to determine if a PD-like brain state alters the response of pramipexole in the discounting paradigm. The final series of studies focused on determining if a limbic brain region involved in reward-related behaviors is also altered by acute and/or chronic pramipexole exposure. Work from our laboratory and others suggest that the ventral pallidum (VP) would be a region of interest. The VP mediates responses to rewards and VP neural activity integrates predictive, incentive, and reward value information. As studies show that pramipexole can alter aspects of impulsivity, such as risk-taking, and enhance motivational salience of reward-related cues, it is possible that the VP plays a role in mediating effects of pramipexole. Accordingly, we hypothesized that VP neuronal activity is altered by behaviorally relevant doses of pramipexole. We utilized single-cell extracellular electrophysiological techniques to investigate effects of systemic pramipexole on VP neuronal firing rate. Finally, as D3Rs can mediate reward-seeking behavior, we investigated the influence of D3Rs in the ability of pramipexole to alter VP neuronal firing rate using PG01037, a D3R-preferring antagonist. Collectively, my studies demonstrate that acutely administered pramipexole enhances risk-taking in rats and also modulates VP neuronal firing rate; this modulation appears to be mediated by D3R activation. Chronic pramipexole treatment enhances risking-taking compared to acute treatment. Chronic treatment also enhances the potency of PPX to alter VP neuronal firing rate. Finally, these studies suggest that a PD-like brain state does not alter pramipexole-induced alterations in risk-taking

Locomotion Induced by Non-Contingent Intracranial Stimulation:

Non-contingent experimenter-applied stimulation (nEAS) to the ventral mesencephalon, unlike contingent intracranial selfstimulation (ICSS), elicits high rates of general locomotion. This locomotion may be due to the nature of the presentation of stimulation, in that nEAS is non-contingent, while ICSS depends on a specific and focused response (e.g., bar pressing). Psychomotor stimulants also elicit high amounts of general locomotion, with the locomotion attributed to increased dopamine release. Interestingly, dopamine release decreases or is absent with repeated ICSS, but not nEAS. This suggests that the locomotion elicited by nEAS may be the result of DA release similar to that observed with psychomotor stimulants. To determine the relationship between locomotion induced by nEAS and psychomotor stimulants, locomotion elicited by nEAS was directly compared to that produced by cocaine, a psychomotor stimulant and indirect DA agonist. Six groups of rats were examined: (1) DA+ group: rats were implanted with a stimulating electrode in the ventral mesencephalon and activation of DA neurons was verified during surgery by monitoring DA release in the striatum; (2) DA− group: rats were also implanted with stimulating electrodes, but the location in the ventral mesencephalon did not elicitDArelease; (3) 10-mg/kg cocaine group: rats were exposed to a low dose (10 mg/kg) of cocaine; (4) 40-mg/kg cocaine group: rats were exposed to a high dose (40 mg/kg) of cocaine; (5) saline group: rats were injected with saline; and (6) naive group: rats received no treatment. The topography of behavior was assessed in all rats during four periods: a pre-treatment baseline, treatment, early post-treatment, and a late post-treatment end point. The results suggest that locomotion elicited by nEAS was stereotypic, dependent upon DA release and similar, but not identical, to psychomotor stimulant-induced locomotion

Locomotion Induced by Non-Contingent Intracranial Electrical Stimulation: Dopamine Dependence and General Characteristics

Intracranial self-stimulation (ICSS) is induced by delivery of electrical stimulation contingent upon a response such as bar pressing. This procedure has been widely used to investigate the brain reward system. Recent investigations, however, have noted that non-contingent electrical stimulation, also called experimenter applied stimulation (EAS), produces a unique set of locomotion behaviors that appear to be related to ICSS, and that these behaviors resemble locomotion similar to those elicited by dopamine enhancing drugs. However, little is known about the general characteristics of EAS-induced locomotion. While ICSS appears to be robust, long lasting, and highly rewarding in that the rat will invest vast amounts of time or energy to obtain the electrical stimulation, these parameters have not been explored for EAS. Moreover, the dopamine dependence of EAS-evoked locomotion is also not firmly established. Thus, the present study investigated dopamine dependence and general characteristics of the EAS-induced locomotion to determine its similarity to ICSS. Results suggested that motor and limbic systems were strongly activated by non-contingent EAS, and that the resulting locomotion was dopamine dependent, robust, continued across long time horizons, and was greater than that evoked by contingent electrical stimulation