New analogs of nortopsentin, a natural 2,4-bis(3′-indolyl)imidazole alkaloid, in which the central imidazole ring of the natural lead was replaced by a 1,2,4-oxadiazole moiety, and in which a 7-azaindole portion substituted the original indole moiety, were efficiently synthesized. Among all derivatives, prescreened against the HCT-116 colon rectal carcinoma cell line, the two most active compounds were selected and further investigated in different human tumor cells showing IC₅₀ values in the micromolar and submicromolar range. Flow cytometric analysis of propidium iodide-stained MCF-7 cells demonstrated that both the active derivatives caused cell cycle arrest in the G0–G1 phase. The cell death mechanism induced by the compounds was considered to be apoptotic by measuring the exposure of phosphatidylserine to the outer membrane and observed morphological evaluation using acridine orange/ethidium bromide double staining. Moreover, further tested on intestinal normal-like differentiated Caco-2 cell line, they exhibited preferential toxicity towards cancer cells.

Based on the established neuroprotective properties of indole-based compounds and their significant potential as multi-targeted therapeutic agents, a series of synthetic indole–phenolic compounds was evaluated as multifunctional neuroprotectors. Each compound demonstrated metal-chelating properties, particularly in sequestering copper ions, with quantitative analysis revealing approximately 40% chelating activity across all the compounds. In cellular models, these hybrid compounds exhibited strong antioxidant and cytoprotective effects, countering reactive oxygen species (ROS) generated by the Aβ(25–35) peptide and its oxidative byproduct, hydrogen peroxide, as demonstrated by quantitative analysis showing on average a 25% increase in cell viability and a reduction in ROS levels to basal states. Further analysis using thioflavin T fluorescence assays, circular dichroism, and computational studies indicated that the synthesized derivatives effectively promoted the self-disaggregation of the Aβ(25–35) fragment. Taken together, these findings suggest a unique profile of neuroprotective actions for indole–phenolic derivatives, combining chelating, antioxidant, and anti-aggregation properties, which position them as promising compounds for the development of multifunctional agents in Alzheimer’s disease therapy. The methods used provide reliable in vitro data, although further in vivo validation and assessment of blood–brain barrier penetration are needed to confirm therapeutic efficacy and safety.

The endoplasmic reticulum (ER) is a dynamic structure, playing multiple roles including calcium storage, protein synthesis and lipid metabolism. During cellular stress, variations in ER homeostasis and its functioning occur. This condition is referred as ER stress and generates a cascade of signaling events termed unfolded protein response (UPR), activated as adaptative response to mitigate the ER stress condition. In this regard, calcium levels play a pivotal role in ER homeostasis and therefore in cell fate regulation since calcium signaling is implicated in a plethora of physiological processes, but also in disease conditions such as neurodegeneration, cancer and metabolic disorders. A large body of emerging evidence highlighted the functional role of TRP channels and their ability to promote cell survival or death depending on endoplasmic reticulum stress resolution, making them an attractive target. Thus, in this review we focused on the TRP channels’ correlation to UPR-mediated ER stress in disease pathogenesis, providing an overview of their implication in the activation of this cellular response.