This review is devoted to the problems of the common features linking metabolic disorders and type 2 diabetes with the development of Alzheimer’s disease. The pathogenesis of Alzheimer’s disease closely intersects with the mechanisms of type 2 diabetes development, and an important risk factor for both pathologies is aging. Common pathological mechanisms include both factors in the development of oxidative stress, neuroinflammation, insulin resistance, and amyloidosis, as well as impaired mitochondrial dysfunctions and increasing cell death. The currently available drugs for the treatment of type 2 diabetes and Alzheimer’s disease have limited therapeutic efficacy. It is important to note that drugs used to treat Alzheimer’s disease, in particular acetylcholinesterase inhibitors, show a positive therapeutic potential in the treatment of type 2 diabetes, while drugs used in the treatment of type 2 diabetes can also prevent a number of pathologies characteristic for Alzheimer’s disease. A promising direction in the search for a strategy for the treatment of type 2 diabetes and Alzheimer’s disease may be the creation of complex multi-target drugs that have neuroprotective potential and affect specific common targets for type 2 diabetes and Alzheimer’s disease.

The development of multi-target-directed ligands (MTDLs) would provide effective therapy of neurodegenerative diseases (ND) with complex and nonclear pathogenesis. A promising method to create such potential drugs is combining neuroactive pharmacophoric groups acting on different biotargets involved in the pathogenesis of ND. We developed a synthetic algorithm for the conjugation of indole derivatives and methylene blue (MB), which are pharmacophoric ligands that act on the key stages of pathogenesis. We synthesized hybrid structures and performed a comprehensive screening for a specific set of biotargets participating in the pathogenesis of ND (i.e., cholinesterases, NMDA receptor, mitochondria, and microtubules assembly). The results of the screening study enabled us to find two lead compounds (4h and 4i) which effectively inhibited cholinesterases and bound to the AChE PAS, possessed antioxidant activity, and stimulated the assembly of microtubules. One of them (4i) exhibited activity as a ligand for the ifenprodil-specific site of the NMDA receptor. In addition, this lead compound was able to bypass the inhibition of complex I and prevent calcium-induced mitochondrial depolarization, suggesting a neuroprotective property that was confirmed using a cellular calcium overload model of neurodegeneration. Thus, these new MB-cycloalkaneindole conjugates constitute a promising class of compounds for the development of multitarget neuroprotective drugs which simultaneously act on several targets, thereby providing cognitive stimulating, neuroprotective, and disease-modifying effects.

Currently, there are no effective drugs for the treatment of amyotrophic lateral sclerosis (ALS). Only two drugs—edaravone and riluzole—have been approved, but they have very limited efficacy. The aim of this work was to modify the structural core of the Edaravone—phenylpyrazolone moiety and combine it with aminoadamantane pharmacophore in order to expand the spectrum of its action to a number of processes involved in the pathogenesis of ALS. New conjugates of edaravone derivatives with 1-aminoadamantanes combined with alkylene or hydroxypropylene spacers were synthesized, and their biological activity was investigated. Compounds were found that could inhibit lipid peroxidation and calcium-related mitochondrial permeability, block fast sodium currents of CNS neurons, and reduce aggregation of the mutated form of the FUS-protein typical to ALS. So, the proposed modification of the edaravone molecule has allowed the obtaining of new original structures that combine some prospective therapeutic mechanisms against key chains of the pathogenesis of ALS. The identified lead compounds can be used for further optimization and development of new promising drugs on this basis for the treatment of ALS.

Mitochondrial permeability transition pore (MPTp) opening is a critical event in neurodegeneration, representing a point of no return in cell death cascades. Despite the neuroprotective potential of MPTp inhibitors, systematic structure–activity relationship (SAR) studies for this target remain scarce. Here we present the first standardized dataset of 57 γ-carboline derivatives evaluated for their ability to inhibit MPTp under uniform experimental conditions. Using complementary Free–Wilson and 2D-QSAR analyses, we expertly propose rational structure–activity relationships (SAR) for this scaffold. Based on the Free–Wilson analysis, we assume that increasing lipophilicity and steric bulk at all four substitution positions to a certain limit positively correlates with inhibitory activity. The R3 linker plays a critical role: the presence of positively ionizable amine groups and potentially hydrogen bond donors enhances activity, whereas non-ionizable amide linkers may be detrimental. The QSAR model based on physicochemical descriptors of substituents corroborates these findings, with positive contributions from cLogP and HBD descriptors. This integrated computational–experimental approach provides a predictive framework for the rational design of novel neuroprotective agents targeting MPTp, with potential implications for the treatment of neurodegenerative diseases.