Bisavenathramide Analogues as Nrf2 Inductors and Neuroprotectors in In Vitro Models of Oxidative Stress and Hyperphosphorylation

Oxidative stress is crucial to the outbreak and advancement of neurodegenerative diseases and is a common factor to many of them. We describe the synthesis of a library of derivatives of the 4-arylmethylen-2-pyrrolin-5-one framework by sequential application of a three-component reaction of primary amines, β-dicarbonyl compounds, and α-haloketones and a Knoevenagel condensation. These compounds can be viewed as cyclic amides of caffeic and ferulic acids, and are also structurally related to the bisavenanthramide family of natural antioxidants. Most members of the library showed low cytotoxicity and good activity as inductors of Nrf2, a transcription factor that acts as the master regulator of the antioxidant response associated with activation of the antioxidant response element (ARE). Nrf2-dependent protein expression was also proved by the significant increase in the levels of the HMOX1 and NQO1 proteins. Some compounds exerted neuroprotective properties in oxidative stress situations, such as rotenone/oligomycin-induced toxicity, and also against protein hyperphosphorylation induced by the phosphatase inhibitor okadaic acid. Compound 3i, which can be considered a good candidate for further hit-to-lead development against neurodegenerative diseases due to its well-balanced multitarget profile, was further characterized by proving its ability to reduce phosphorylated Tau levels

Novel multitarget chiral α7-nAChRs ligands with neuroprotective properties for Alzheimer’s Disease treatment

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Medicina, Departamento de Farmacología. Fecha de lectura: 31-10-2019Esta tesis tiene embargado el acceso al texto completo hasta el 30-04-2021Alzheimer’s Disease (AD) is an age-related, chronic, progressive and continuous neurodegenerative disease and the most common form of dementia worldwide. Because of its high biological complexity, AD is considered a multifactorial disorder. Currently, there are only five Food and Drug Administration (FDA) marketed symptomatic drugs, which cannot stop disease progression. This has led to the development of the new therapeutic strategy of multitarget directed ligands (MTDLs). In this context, we have obtained a two chiral MTDLs families based on important pathological routes involved in AD. Family A de novo synthesised compounds were simultaneously free radical scavengers, Nrf2 inducers, acetylcholinesterase (AChE) inhibitors, α7- neuronal nicotinic acetylcholine receptors (α7-nAChR)-selective ligands and neuroprotectant agents. The pharmacokinetic profile of selected hit compounds was assessed and systemic parameters were evaluated. The neuropharmacokinetic studies revealed they distribute within the brain and bind to brain parenchyma, accumulating intracellularly. However, free unbound drug was low, most probably due to the existence of an active efflux transport across the blood brain barrier. These results were valuable in order to re-design the second generation of MTDLs with advantageous physicochemical properties. Although Nrf2 induction activity was lost in Family B, the excellent free radical scavenger effect, as well as the selective activation of α7-nAChR, remained, leading to higher neuroprotectant activity. These compounds were conceived to be directed to the aforementioned different therapeutic targets, and to act at complementary targets of the neurodegenerative process. Thus, activating the endogen survival cell routes, which could prevent or, at least, slow down the neurodegeneration process of ADLa Enfermedad de Alzheimer (EA) es una enfermedad neurodegenerativa, crónica y progresiva, relacionada con el envejecimiento y es la forma más común de demencia en el mundo. Debido a su extraordinaria complejidad, la EA es considerada una enfermedad multifactorial. En la actualidad, solamente existen cinco fármacos aprobados por la FDA comercializados, los cuales son sintomáticos y no pueden parar la progresión de la enfermedad. Esto ha llevado a desarrollar la nueva estrategia terapéutica de ligandos multidiana. En este contexto, hemos obtenido nos nuevas familias de compuestos multidiana basados en importantes rutas patológicas involucradas en la EA. Los compuestos de novo sintetizados de la Familia A resultaron ser simultáneamente captadores de radicales libres, inductores de Nrf2, inhibidores de AChE, ligandos selectivos de α7-nAChRy agentes neuroprotectores. Además, se realizaron estudios farmacocinéticos y de distribución cerebral con los compuestos seleccionados como cabeza de serie, donde se obtuvieron los parámetros sistémicos y los cuales revelaron que se distribuyen y se unen al parénquima cerebral, acumulándose intracelularmente. Sin embargo, la cantidad de compuesto libre fue muy baja, muy probablemente debido a la existencia de un transporte active de expulsión del cerebro a través de la barrera hematoencefálica. A pesar de ello, estos resultados fueron valiosos para rediseñar una segunda generación de compuestos multidiana con propiedades fisicoquímicas mejoradas. Aunque se perdió la actividad de inducción de Nrf2, los compuestos de la Familia B mostraron un potente efecto secuestrador de radicales libres, así como mantuvieron la activación selectiva de los α7-nAChR, dando lugar a una mayor capacidad neuroprotectora. Estos compuestos fueron concebidos para ser dirigidos a diferentes dianas terapéuticas, con el fin de actuar sobre rutas complementarias del proceso neurodegenerativo. De este modo, mediante la activación de rutas de supervivencia endógenas, se podría evitar o, al menos, ralentizar el proceso neurodegenerativo de la E

Inclusion complex of ITH12674 with2-hydroxypropyl-beta-cyclodextrin: Preparation, physical characterization and pharmacological effect

ITH12674 is a multitarget drug, designed to exert a dual “drug-prodrug” mechanism of action, able toinduce the phase II antioxidant and anti-inflammatory response for the treatment of brain ischemia.However, its physicochemical properties limit its potential preclinical development due to its low watersolubility and instability towards heat and pH variations. In order to improve its properties, we preparedthe inclusion complex of ITH12674 with 2-hydroxypropyl- -cyclodextrin (HP- -CD) by the freeze-drying method. The formation of the inclusion complex was confirmed by FT-IR spectroscopy, PXRD,DSC,1H NMR and SEM techniques. Experimental results showed that the inclusion complex enhanced itswater solubility and stability against heat, acidic and basic conditions. Furthermore, the inclusion com-plex, prepared in water solution, exerted the same potency to induce the phase II antioxidant response asthe pure ITH12674. Thus the formation of the inclusion complex with HP- -CD is a very effective methodto stabilize and solubilize the active compound for its future preclinical development.European Commission-ERCInstituto de Salud Carlos IIIFundación FIPSEInstituto-Fundación Teófilo HernandoDepto. de Química en Ciencias FarmacéuticasFac. de FarmaciaTRUEpu

New melatonin–cinnamate hybrids as multi-target drugs for neurodegenerative diseases: Nrf2-induction, antioxidant effect and neuroprotection

Neurodegenerative diseases share many pathological pathways, such as abnormal protein aggregation, mitochondrial dysfunction, extensive oxidative stress and neuroinflammation. Cells have an intrinsic mechanism of protection, the Nrf2 transcriptional factor, known as the master regulator of redox homeostasis. Results: Based on the common features of these diseases we have designed a multi-target hybrid structure derived from melatonin and ethyl cinnamate. The obtained derivatives were Nrf2 inducers and potent-free radical scavengers. These new compounds showed a very interesting neuroprotective profile in several in vitro models of oxidative stress, Alzheimer's disease and brain ischemia. Conclusion: We have designed a new hybrid structure with complementary activities. We have identified compound 5h as an interesting Nrf2 inducer, very potent antioxidant and neuroprotectant.European CommissionMinisterio de Sanidad(España)Ministerio de Economía, Comercio y Empresa(España)Instituto de Salud Carlos IIIMinisterio de Educación, Cultura y Deporte(España)Depto. de Química en Ciencias FarmacéuticasFac. de FarmaciaTRUEpu

New melatonin–cinnamate hybrids as multi-target drugs for neurodegenerative diseases: Nrf2-induction, antioxidant effect and neuroprotection

Neurodegenerative diseases share many pathological pathways, such as abnormal protein aggregation, mitochondrial dysfunction, extensive oxidative stress and neuroinflammation. Cells have an intrinsic mechanism of protection, the Nrf2 transcriptional factor, known as the master regulator of redox homeostasis. Results: Based on the common features of these diseases we have designed a multi-target hybrid structure derived from melatonin and ethyl cinnamate. The obtained derivatives were Nrf2 inducers and potent-free radical scavengers. These new compounds showed a very interesting neuroprotective profile in several in vitro models of oxidative stress, Alzheimer's disease and brain ischemia. Conclusion: We have designed a new hybrid structure with complementary activities. We have identified compound 5h as an interesting Nrf2 inducer, very potent antioxidant and neuroprotectant.European CommissionMinisterio de Sanidad(España)Ministerio de Economía, Comercio y Empresa(España)Instituto de Salud Carlos IIIMinisterio de Educación, Cultura y Deporte(España)Depto. de Química en Ciencias FarmacéuticasFac. de FarmaciaTRUEpu