Sub-acute toxicity evaluation of aqueous leaf extract from Passiflora edulis Sims f. edulis (Gulupa) in Wistar rats.

The genus Passiflora (Passifloraceae) comprises about 500 species. The Passiflora edulis stands out because of its economic and medicinal importance. It is widely planted in tropical and subtropical regions worldwide, especially in South America, the Caribbean, South Africa, and Asia. The aqueous extract of Passiflora edulis Sims f. edulis (Gulupa) leaves is used in traditional medicine for its soothing and tranquilizing effects on the central nervous system. Therefore, evaluating its safety for human use is a fundamental requirement to continue the development of new therapies within the framework of regulatory, preclinical, and clinical guidelines. Here, the sub-acute toxicity study was conducted following the Organization for Economic Cooperation and Development (OECD) guideline 407 for 28 days in Wistar albino rats. The study showed that 1000 mg/kg/day of the aqueous extract in 10 adult Wistar rats (five males and five females) was well tolerated. The hematological results are at normal levels. However, monocytopenia and eosinopenia were observed with a significant difference (P < 0,05) for both male and female rats treated with the aqueous extract of Passiflora edulis. The results show that liver and kidney function profiles were conserved. However, an increase in ALT is observed with significant differences between male and female rats treated with the extract compared to the controls. Study findings were limited to non-adverse histopathological results of a slightly increased incidence of focal periportal lymphocytic infiltrate in the liver and focal corticomedullary nephrocalcinosis in the kidney compared to control. Therefore, the aqueous extract of Passiflora edulis has a good safety profile in oral administration, was well tolerated, and did not cause any lethality or adverse effects in the sub-acute toxicity study in male and female rats. The NOAEL (no observed adverse effect level) for the 28-day subacute toxicity study was considered to be 1000 mg/kg.

Dendritogenic Potential of the Ethanol Extract from Lippia alba Leaves in Rat Cortical Neurons.

A reduced dendritic complexity, especially in regions such as the hippocampus and the prefrontal cortex, has been linked to the pathophysiology of some neuropsychiatric disorders, in which synaptic plasticity and functions such as emotional and cognitive processing are compromised. For this reason, the identification of new therapeutic strategies would be enriched by the search for metabolites that promote structural plasticity. The present study evaluated the dendritogenic potential of the ethanol extract of Lippia alba, an aromatic plant rich in flavonoids and terpenes, which has been widely used in traditional medicine for its presumed analgesic, anxiolytic, and antidepressant potential. An in vitro model of rat cortical neurons was used to determine the kinetics of the plant's effect at different time intervals. Changes in morphological parameters of the neurons were determined, as well as the dendritic complexity, by Sholl analysis. The extract promotes the outgrowth of dendritic branching in a rapid and sustained fashion, without being cytotoxic to the cells. We found that this effect could be mediated by the phosphatidylinositol 3-kinase pathway, which is involved in mechanisms of neuronal plasticity, differentiation, and survival. The evidence presented in this study provides a basis for further research that, through in vivo models, can delve into the plant's therapeutic potential.

An update on neurobiological mechanisms involved in the development of chemotherapy-induced cognitive impairment (CICI).

Cancer is the second leading cause of death worldwide despite efforts in early diagnosis of the disease and advances in treatment. The use of drugs that exert toxic effects on tumor cells or chemotherapy is one of the most widely used treatments against cancer. However, its low toxic selectivity affects both healthy cells and cancer cells. It has been reported that chemotherapeutic drugs may generate neurotoxicity that induces deleterious effects of chemotherapy in the central nervous system. In this sense, patients report decreased cognitive abilities, such as memory, learning, and some executive functions after chemotherapy. This chemotherapy-induced cognitive impairment (CICI) develops during treatment and persists even after chemotherapy. Here we present a review of the literature on the main neurobiological mechanisms involved in CICI using a Boolean formula following the steps of the PRISMA guidelines that were used to perform statements searches in various databases. The main mechanisms described in the literature to explain CRCI include direct and indirect mechanisms that induce neurotoxicity by chemotherapeutic agents. Therefore, this review provides a general understanding of the neurobiological mechanisms of CICI and the possible therapeutic targets to prevent it..

Cell surface markers for mesenchymal stem cells related to the skeletal system: A scoping review.

Multipotent mesenchymal stromal cells (MSCs) have been described as bone marrow stromal cells, which can form cartilage, bone or hematopoietic supportive stroma. In 2006, the International Society for Cell Therapy (ISCT) established a set of minimal characteristics to define MSCs. According to their criteria, these cells must express CD73, CD90 and CD105 surface markers; however, it is now known they do not represent true stemness epitopes. The objective of the present work was to determine the surface markers for human MSCs associated with skeletal tissue reported in the literature (1994-2021). To this end, we performed a scoping review for hMSCs in axial and appendicular skeleton. Our findings determined the most widely used markers were CD105 (82.9%), CD90 (75.0%) and CD73 (52.0%) for studies performed in vitro as proposed by the ISCT, followed by CD44 (42.1%), CD166 (30.9%), CD29 (27.6%), STRO-1 (17.7%), CD146 (15.1%) and CD271 (7.9%) in bone marrow and cartilage. On the other hand, only 4% of the articles evaluated in situ cell surface markers. Even though most studies use the ISCT criteria, most publications in adult tissues don't evaluate the characteristics that establish a stem cell (self-renewal and differentiation), which will be necessary to distinguish between a stem cell and progenitor populations. Collectively, MSCs require further understanding of their characteristics if they are intended for clinical use.

Sphingolipids and their role in health and disease in the central nervous system.

Sphingolipids (SLs) are lipids derived from sphingosine, and their metabolism involves a broad and complex network of reactions. Although SLs are widely distributed in the body, it is well known that they are present in high concentrations within the central nervous system (CNS). Under physiological conditions, their abundance and distribution in the CNS depend on brain development and cell type. Consequently, SLs metabolism impairment may have a significant impact on the normal CNS function, and has been associated with several disorders, including sphingolipidoses, Parkinson's, and Alzheimer's. This review summarizes the main SLs characteristics and current knowledge about synthesis, catabolism, regulatory pathways, and their role in physiological and pathological scenarios in the CNS.

Role of Connexins 30, 36, and 43 in Brain Tumors, Neurodegenerative Diseases, and Neuroprotection.

Gap junction (GJ) channels and their connexins (Cxs) are complex proteins that have essential functions in cell communication processes in the central nervous system (CNS). Neurons, astrocytes, oligodendrocytes, and microglial cells express an extraordinary repertory of Cxs that are important for cell to cell communication and diffusion of metabolites, ions, neurotransmitters, and gliotransmitters. GJs and Cxs not only contribute to the normal function of the CNS but also the pathological progress of several diseases, such as cancer and neurodegenerative diseases. Besides, they have important roles in mediating neuroprotection by internal or external molecules. However, regulation of Cx expression by epigenetic mechanisms has not been fully elucidated. In this review, we provide an overview of the known mechanisms that regulate the expression of the most abundant Cxs in the central nervous system, Cx30, Cx36, and Cx43, and their role in brain cancer, CNS disorders, and neuroprotection. Initially, we focus on describing the Cx gene structure and how this is regulated by epigenetic mechanisms. Then, the posttranslational modifications that mediate the activity and stability of Cxs are reviewed. Finally, the role of GJs and Cxs in glioblastoma, Alzheimer's, Parkinson's, and Huntington's diseases, and neuroprotection are analyzed with the aim of shedding light in the possibility of using Cx regulators as potential therapeutic molecules.

Cytoprotective action against oxidative stress in astrocytes and neurons by Bactris guineensis (L.) H.E. Moore (corozo) fruit extracts.

Neurodegenerative conditions such as Alzheimer's disease, Parkinson's disease and amyotrophic lateral sclerosis are characterized by having a significant increase in oxidative stress that can lead to the cellular damage of both neurons and astrocytes. Therefore, the search for molecules that can modulate oxidative stress in these diseases has recently gain interest, especially for those non-traditional antioxidants that can be gained from diet. In the present work, pulp and seed extracts from the fruit of the palm, Bactris guineensis were obtained by hydro-alcoholic solution and by a solid-liquid phase using solvents with different polarities and evaluated for their capacity to protect both neurons and astrocytes against rotenone-induced oxidative stress. Analysis of the chemical antioxidant activity showed that Bactris guineensis pulp crude extract and seed ethyl acetate and ethanol extracts had a high scavenging capacity when compared with extracts obtained in Hexane and dichloromethane. Toxicity assays also showed that the pulp crude extract and seed ethyl acetate and ethanol extracts at low doses did not affect the cell viability of primary astrocyte and SH-SY5Y neuroblastoma cells. In addition, ethyl acetate and ethanol extracts, not only decreased O2- radicals production but also protected both SHSY5Y and astrocytes oxidative stress induced by rotenone. Together our results suggest that Bactris guineensis fruit contain antioxidant molecules that can have therapeutic potential.

L-Glutamato: un aminoácido clave para las funciones sensoriales y metabólicas / L-glutamate: a key amino acid for sensory and metabolic functions

El ácido glutámico como tal o en su forma ionizada L-glutamato (GLU) es uno de los aminoácidos más abundantes en la naturaleza debido a que cumple funciones importantes a nivel celular y sistémico. En el intestino y el hígado, por ejemplo, el GLU constituye fuente de energía y es precursor de moléculas de relevancia biológica. Mientras que en el sistema nervioso central de los mamíferos actúa como neurotransmisor excitatorio, debido a la interacción con receptores específicos distribuidos en el cerebro. Además al GLU se le ha relacionado con la potenciación a corto y largo plazo de la memoria y el aprendizaje. Por otro lado, el consumo de GLU o de su sal monosódica (GMS) como aditivo alimentario genera el gusto umami, palabra japonesa que significa sabroso. El consumo de GMS ha sido considerado seguro por diferentes organizaciones que evalúan la inocuidad de uso de los aditivos alimentarios, razón por la cual han establecido una ingesta diaria admisible (IDA) "no especificada" y lo clasifican como un ingrediente reconocido como seguro o sustancia GRAS (por sus siglas en inglés, Generally Recognized Safe Substance). En esta revisión se presentan los aspectos del metabolismo del GLU, su papel en la degustación de los alimentos y la inocuidad del uso del GMS(AU)

Glutamic acid or its ionic form L-glutamate (GLU) is one of the most abundant amino acids in nature and it plays important functions at the cellular and systemic levels. For instance, in the intestine and liver, GLU is a source of energy and is the precursor of key biological molecules. At the central nervous system of mammals, GLU acts as an excitatory neurotransmitter due to the interaction with specific receptors. In addition, GLU has been related with short- and long-term potentiation, memory and the learning. Furthermore, consumption of GLU or its monosodium salt (monosodium glutamate, MSG) as a food additive is responsible for the umami taste. The consumption of MSG has been considered safe for different agencies responsible for the evaluation of the safe use of food additives, which have establish an Acceptable Daily Intake (ADI) “not specified”, or classified as Generally Recognized Safe Substance (GRAS). This review focuses on important metabolic aspects of GLU and its role in food tasting and MSG safety(AU)

L-glutamate: a key amino acid for senory and metabolic functions.

Glutamic acid or its ionic form L-glutamate (GLU) is one of the most abundant amino acids in nature and it plays important functions at the cellular and systemic levels. For instance, in the intestine and liver, GLU is a source of energy and is the precursor of key biological molecules. At the central nervous system of mammals, GLU acts as an excitatory neurotrausmitter due to the interaction with specific receptors. In addition, GLU has been related with short- and long-term potentiation, memory and the learning. Furthermore, consumption of GLU or its monosodium salt (monosodium glutamate, MSG) as a food additive is responsible for the umami taste. The consumption of MSG has been considered safe for different agencies responsible for the evaluation of the safe use of food additives, which have establish an Acceptable Daily Intake (ADI) "not specified", or classified as Generally Recognized Safe Substance (GRAS). This review focuses on important metabolic aspects of GLU and its role in food tasting and MSG safety.

Cellular and molecular mechanisms of antioxidants in Parkinson's disease.

Parkinson's disease (PD) is a neurodegenerative movement disorder characterized by the degeneration and progressive loss of dopaminergic neurons in the substantia nigra pars compacta. It has been suggested that oxidative stress plays a role in the etiology and progression of PD. For instance, low levels of endogenous antioxidants, increased reactive species, augmented dopamine oxidation, and high iron levels have been found in brains from PD patients. In vitro and in vivo studies of Parkinson models evaluating natural and endogenous antioxidants such as polyphenols, coenzyme Q10, and vitamins A, C, and E have shown protective effects against oxidative-induced neuronal death. In this paper, we will review the mechanisms by which polyphenols and endogenous antioxidants can produce protection. Some of the mechanisms reviewed include: scavenging nitrogen and oxygen reactive species, regulation of signaling pathways associated with cell survival and inflammation, and inhibition of synphilin-1 and alpha-synuclein aggregation.

Effects of natural antioxidants in neurodegenerative disease.

Polyphenols are secondary metabolites with antioxidant properties and are abundant in the diet. Fruits, vegetables, herbs, and various drinks (tea, wine, and juices) are all sources of these molecules. Despite their abundance, investigations into the benefits of polyphenols in human health have only recently begun. Phenolic compounds have received increasing interest because of numerous epidemiological studies. These studies have suggested associations between the consumption of polyphenol-rich aliments and the prevention of chronic diseases, such as cancer, cardiovascular diseases, and neurodegenerative diseases. More specifically, in the last 10 years literature on the neuroprotective effects of a polyphenol-rich diet has grown considerably. It has been demonstrated, in various cell culture and animal models, that these metabolites are able to protect neuronal cells by attenuating oxidative stress and damage. However, it remains unclear as to how these compounds reach the brain, what concentrations are necessary, and what biologically active forms are needed to exert beneficial effects. Therefore, further research is needed to identify the molecular pathways and intracellular targets responsible for polyphenol's neuroprotective effects. The aim of this paper is to present various well-known dietary polyphenols and their mechanisms of neuroprotection with an emphasis on Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis.

Purificación y determinación de carbohidratos en la vicilina de Canavalia ensiformis / Purification and carbohydrate determination of vicilin from Canavalia ensiformis

Este estudio reporta la purificación y determinación de carbohidratos en la vicilina de Canavalia ensiformis ( Jack bean). La vicilina se purificó por precipitación isoeléctrica a pH 6,4 y 4,8, cromatografía de intercambio iónico (DEAE -Sephadex A-50) y cromatografía de afinidad (Con A -Sepharosa 4B). La pureza de la proteína se verificó por SDS-PAGE y su identidad se confirmó por espectrometría de masas empleando la técnica de ionización MALDI (desorción-ionización con láser asistida por una matriz) en un espectrómetro de tiempo de vuelo (TOF) obteniéndose un espectro de masas característico de la proteína (PMF) (MALDI-TOF-PMF).La oxidación de residuos glicosídicos en la vicilina demostró la presencia de carbohidratos en la proteína, lo cual se corroboró por deglicosilación enzimática con Péptido N-glicosidasa F (PNGasa F) y por el método de Dubois, el cual mostró un contenido de carbohidratos del 4,03% en la proteína. Estos resultados muestran, por primera vez, la presencia de glicósidos en la vicilina de Canavalia ensiformis.El proceso de purificación de la vicilina de la semilla de Canavalia ensiformis, desarrollado en este trabajo, permitió obtener la proteína con un grado de pureza muy superior al descrito previamente en la literatura.

This study reports the purification and carbohydrate determination of vicilin from anavalia ensiformis (Jack bean). The vicilin was purified by isoelectric precipitation at pH 6.4 and 4.8, ion exchange chromatography (deae-Sephadex A-50) and affinity chromatography (Con A -Sepharosa 4B). Protein identity was confirmed by mass spectrometry (maldi-tof-pmf) (Matrix assisted laser desorption ionizationtime of flight-Peptide mass fingerprinting) and purification was confirmed by sdspage. Oxidation of glycosylated moiety in pure vicilin demonstrates the presence of carbohydrates in the protein. The presence of carbohydrates in the pure vicilin fraction was confirmed by enzymatic deglycosylation by Peptide N-glycosidase F (PNGasa F) and by Dubois’ method, finding a 4.03% carbohydrate content in such protein. These results demonstrate for the first time the presence of glycosides in C. ensiformis vicilin. The purification process of vicilin seed of Canavalia Ensiformis used in this study allowed us to obtain a protein with a high degree of purity, superior to the ones described in the literature.

Modelo integrador para las rutas de señalización diferencial del receptor ionotrópico de glutamato activado por el N-metil-D-aspartato / Integrative Model for Differential Signaling Pathways of the Ionotropic Glutamate Receptor Activated by N-methyl-D-aspartate

El receptor ionotrópico de glutamato activado por N-metil-D-aspartato (iGluR-NMDA) es un complejo macromolecular heteromultimérico constituido por entre 3 y 5 subunidades de tres diferentes tipos, a saber: NR1, NR2A-D y NR3A y B. Se ha demostrado su participación activa en prácticamente todos los procesos fisiológicos, patológicos e intermediarios de efectos farmacológicos que ocurren en las células de tejidos excitables, inclusive se ha reportado su presencia en otros tejidos no excitables. En el sistema nervioso central (SNC) participa en los procesos de aprendizaje, memoria, plasticidad, diferenciación, migración de la célula neural y apoptosis. Además, en los eventos de índole farmacológica se ha demostrado su intervención en excitotoxicidad, drogadicción y alcoholismo. Surge entonces la pregunta de cómo un mismo complejo macromolecular puede participar en tantos y tan diversos procesos. La revisión de literatura en la que se demuestra la interacción del iGluR-NMDA con proteínas de señalización, soporte, adaptadoras, moduladoras, de adhesión celular, de citoesqueleto y enzimas reporta un conjunto de más de 160 moléculas que participan en las cascadas que generan las señales a diferentes niveles de interacción y con diferentes sustratos. En este artículo se presenta un modelo predictivo estructural y funcional que permite distinguir, por lo menos, tres rutas diferenciadas de señalización.

The ionotropic glutamate receptor activated by N-methyl-D-aspartate (iGluR-NMDA) is a multiheteromeric complex constituted from by three to five subunits belonging to by three different kinds of subunits known as NR1, NR2AD y NR3A y B. It is well established the participation of iGluR-NMDA complexes in a broad range of physiological, pathological, and as intermediary in pharmacological processes of neural systems. In the CNS, iGluR-NMDA participates in learning, memory, plasticity, neural differentiation, neural migration, and apoptosis, among others. In addition, from the pharmacological point of view the iGluR-NMDA is playing a role in excitotoxicity, drugs-addiction and other dependences. How the same complex can participate in a significant broad group of neural activities is a valid question after a literature review. A carefully analysis shows that iGluR-NMDA interacts, at some level, with a big number of intracellular proteins belonging to signaling proteins family, support proteins, modulator proteins, cytoskeleton, and enzymes, resulting in interactions with more than a 160 proteins, at different interaction levels and acting with intracellular proteins. In this work we report a proposal for a model of differential signaling cascade pathways generated by the iGluR-NMDA gating. The model shows at least the possibility of three different signaling pathways.