Neuroprotective natural products: promising candidates against neurodegenerative diseases / Productos naturales con propiedades neuroprotectivas: posibles candidatos para el tratamiento de enfermedades neurodegenerativas

Neurodegeneration is a progressive loss of neurons both structurally and functionally causing neuronal cell death ultimately leading to development of various neurodegenerative diseases. Due to poor pharmacokinetic profile of neurotrophins, there still remains a challenge in their neurotrophic therapy where plants, bacteria and fungi, as natural products, could act as promising candidates against various neurological disorders by modulating the neurotrophic activity. Therefore, these natural products that mimic neurotrophins, could develop novel therapeutic approaches to herbal drug that can ameliorate neurodegenerative diseases such as Parkinson's disease, Alzheimer's disease and other associated neurological disorders. Taking into account the failure of strategies involving single neurotrophins for the treatment of neurodegenerative diseases, we propose a combination of small molecules of natural products that may work synergistically to restore neuronal functions, minimize side effects and target multiple pathways for a more effective treatment.

La neurodegeneración es una pérdida progresiva de neuronas, tanto estructural como funcional, que causa la muerte neuronal, lo que conduce al desarrollo de diversas enfermedades neurodegenerativas. Debido al pobre perfil farmacocinético de las neurotrofinas, existe un desafío en su terapia neurotrófica donde plantas, bacterias y hongos, como productos naturales, podrían actuar como candidatos contra diversos trastornos neurológicos al modular la actividad neurotrófica. Estos productos naturales que asemejan a las neurotrofinas podrían desarrollar enfoques terapéuticos novedosos como medicamentos a base de hierbas que pueden mejorar enfermedades neurodegenerativas como: Parkinson, Alzheimer y otros trastornos neurológicos asociados. Teniendo en cuenta el fracaso de las estrategias terapéuticas de neurotrofinas para las enfermedades neurodegenerativas, proponemos una combinación de pequeñas moléculas de productos naturales que pueden funcionar sinérgicamente para restaurar las funciones neuronales, minimizar los efectos secundarios y apuntar a múltiples vías para un tratamiento más efectivo.

Nicotine-evoked cytosolic Ca2+ increase and cell depolarization in capillary endothelial cells of the bovine adrenal medulla

Endothelial cells are directly involved in many functions of the cardiovascular system by regulating blood flow and blood pressure through Ca2+ dependent exocitosis of vasoactive compounds. Using the Ca2+ indicator Fluo-3 and the patch-clamp technique, we show that bovine adrenal medulla capillary endothelial cells (B AMCECs) respond to acetylcholine (ACh) with a cytosolic Ca2+ increase and depolarization of the membrane potential (20.3±0.9 mV; n=23). The increase in cytosolic Ca2+ induced by 10µM ACh was mimicked by the same concentration of nicotine but not by muscarine and was blocked by 100 µM of hexamethonium. On the other hand, the increase in cytosolic Ca2+ could be depressed by nifedipine (0.01 -100 µM) or withdrawal of extracellular Ca2+. Taken together, these results give evidence for functional nicotinic receptors (nAChRs) in capillary endothelial cells of the adrenal medulla. It suggests that nAChRs in B AMCECs may be involved in the regulation of the adrenal gland's microcirculation by depolarizing the membrane potential, leading to the opening of voltage-activated Ca2+ channels, influx of external Ca2+ and liberation of vasoactive compounds.