Background: Several pre-clinical and clinical reports suggest that HIV-1 protease inhibitors, in addition to the antiretroviral properties, possess pleiotropic pharmacological effects including anticancer action. Therefore, we investigated the pro-apoptotic activity in tumor cells of two molecules, RDD-19 and RDD-142, which are hydroxyethylamine derivatives’ precursors of darunavir and several HIV-1 protease inhibitors. Methods: Three hepatoma cell lines and one non-pathological cell line were treated with RDD-19 and RDD-142, and cell viability was assessed. The expression levels of several markers for ER stress, autophagy, cellular ubiquitination, and Akt activation were quantified in HepG2 cells treated with RDD-19 and RDD-142 to evaluate apoptotic and non-apoptotic cell death. Results: RDD-19 and RDD-142 showed a greater dose-dependent cytotoxicity towards the hepatic tumor cell line HepG2 compared to the non-pathological hepatic cell line IHH. Both molecules caused two types of cell death, a caspase-dependent apoptosis, which was ascertained by a series of biochemical and morphological assays, and a caspase-independent death that was characterized by the induction of ER stress and autophagy. The strong increase of ubiquitinated proteins inside the cells suggested that the target of these molecules could be the proteasome and in silico molecular docking analysis that was used to support the plausibility of this hypothesis. Furthermore, cells treated with the two compounds displayed decreased levels of p-AKT, which interferes with cell survival and proliferation. Conclusions: These findings demonstrate that two compounds, RDD-19 and RDD-142, have pleiotropic effects and that they may represent promising anticancer candidates.

Liver cancer is one of the most common causes of cancer death worldwide. In recent years, substantial progress has been made in the development of systemic therapies, but there is still the need for new drugs and technologies that can increase the survival and quality of life of patients. The present investigation reports the development of a liposomal formulation of a carbamate molecule, reported as ANP0903, previously tested as an inhibitor of HIV-1 protease and now evaluated for its ability to induce cytotoxicity in hepatocellular carcinoma cell lines. PEGylated liposomes were prepared and characterized. Small, oligolamellar vesicles were produced, as demonstrated by light scattering results and TEM images. The physical stability of the vesicles in biological fluids was demonstrated in vitro, alongside the stability during storage. An enhanced cellular uptake was verified in HepG2 cells treated with liposomal ANP0903, resulting in a greater cytotoxicity. Several biological assays were performed to elucidate the molecular mechanisms explaining the proapoptotic effect of ANP0903. Our results allow us to hypothesize that the cytotoxic action in tumor cells is probably due to the inhibition of the proteasome, resulting in an increase in the amount of ubiquitinated proteins within the cells, which in turn triggers activation of autophagy and apoptosis processes, resulting in cell death. The proposed liposomal formulation represents a promising approach to deliver a novel antitumor agent to cancer cells and enhance its activity.

Up-regulated Gene clone 7 (URG7) is a protein localized in the endoplasmic reticulum (ER) and overexpressed in liver cells upon hepatitis B virus (HBV) infection. Its activity has been related to the attenuation of ER stress resulting from HBV infection, promoting protein folding and ubiquitination and reducing cell apoptosis overall. While the antiapoptotic activity of URG7 in HBV-infected cells may have negative implications, this effect could be exploited positively in the field of proteinopathies, such as neurodegenerative diseases. In this work, we aimed to verify the possible contribution of URG7 as a reliever of cellular proteostasis alterations in a neuronal in vitro system. Following tunicamycin-induced ER stress, URG7 was shown to modulate different markers of the unfolded protein response (UPR) in favor of cell survival, mitigating ER stress and activating autophagy. Furthermore, URG7 promoted ubiquitination, and determined a reduction in protein aggregation, calcium release from the ER and intracellular ROS content, confirming its pro-survival activity. Therefore, in light of the results reported in this work, we hypothesize that URG7 offers activity as an ER stress reliever in a neuronal in vitro model, and we paved the way for a new approach in the treatment of neurodegenerative diseases.

The Virus HIV-1 infection still represents a serious disease even if actually it is transformed in chronic pathology. Considering the crucial role of the enzyme Protease in life cycle of HIV many efforts have been made in the research of new organic compounds showing inhibitory activity. After development of several series of non peptidic inhibitors we report here the synthesis of novel simple HIV-Protease inhibitors containing heteroaryl carboxamides and their antiviral activity in vitro and in HEK293 cells. Benzofuryl- benzothienyl- and indolyl rings as well as aryl sulfonamides with different electronic properties have been introduced by efficient synthetic procedures. All compounds showed inhibitory activity similar to the commercial drug Darunavir, effective against both wild-type HIV-1 protease and that containing the V32I or V82A mutations. ADME properties were also evaluated, showing the potential of such compounds to be developed as drugs.

This study focuses on the rational design and synthesis of new pyrrolidinone derivatives aimed at inhibiting the ACE2 receptor, a key entry point for SARS-CoV-2. Building on structural insights from known inhibitors like MLN-4760, five compounds featuring a pyrrolidinone core, with some incorporating indole rings, were synthesized and characterized. Their inhibitory activity against ACE2 was evaluated in vitro, with compound 4 showing the most promising results, further confirmed through cytotoxicity assays and molecular docking studies. Docking analysis revealed favorable binding interactions within the ACE2 active site, supporting the potential of compound 4 as a therapeutic agent. These findings provide a foundation for future in vivo studies and highlight the potential development of novel therapeutics targeting ACE2-related diseases, including COVID-19.

Background/Objectives: The valorization of bioactive compounds from food industry by-products aligns with sustainable development goals and represents a strategy for obtaining functional ingredients. Hazelnut (Corylus avellana L.) skins are a phenolic-rich residue with high antioxidant potential, but their extraction conditions and cellular mechanisms of action remain insufficiently explored. Methods: Ultrasound-assisted extraction was optimized using a 3³ Full Factorial Design (FFD) by investigating temperature (30–50–70 °C), extraction time (1–2–3 h), and solvent composition (water/ethanol). Antioxidant activity was evaluated using multiple in vitro assays, including Total Phenolic Content (TPC), DPPH, ABTS, FRAP, and β-carotene bleaching (BCB) assays. The optimized extract (OE) was chemically characterized by UHPLC–MS/MS and its activity was evaluated in HepG2 cells for biocompatibility, modulation of intracellular ROS levels, and antioxidant pathway activation. Results: Optimal extraction conditions were identified as 30 °C, 70.86 min (1.181 h), and 21.13% ethanol (v/v), yielding an extract with enhanced antioxidant capacity. UHPLC–MS/MS analysis revealed 25 bioactive compounds, mainly flavonoids and phenolic acids, relevant for oxidative stress modulation. The extract significantly reduced tert-butyl hydroperoxide (TBH)-induced intracellular ROS levels, restoring antioxidant proteins involved in the Nuclear Factor erythroid 2-related factor 2 (NRF-2)-mediated defense pathway. Conclusions: The optimized hazelnut skin extract combines strong antioxidant efficacy with cellular compatibility, supporting its potential application as a functional ingredient for nutraceutical and pharmaceutical strategies targeting oxidative stress-related conditions.