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, ß-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.

Inclusion complex of ITH12674 with 2-hydroxypropyl-ß-cyclodextrin: Preparation, physical characterization and pharmacological effect.

ITH12674 is a multitarget drug, designed to exert a dual "drug-prodrug" mechanism of action, able to induce 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 water solubility and instability towards heat and pH variations. In order to improve its properties, we prepared the inclusion complex of ITH12674 with 2-hydroxypropyl-ß-cyclodextrin (HP-ß-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 its water solubility and stability against heat, acidic and basic conditions. Furthermore, the inclusion complex, prepared in water solution, exerted the same potency to induce the phase II antioxidant response as the pure ITH12674. Thus the formation of the inclusion complex with HP-ß-CD is a very effective method to stabilize and solubilize the active compound for its future preclinical development.

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

BACKGROUND: 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.