In recent years, there has been a growing scientific and clinical interest in nutraceuticals, bioactive compounds derived from natural sources such as plants, fruits and cereals. These substances have gained prominence due to their diverse pharmacological properties, particularly their anti-inflammatory, antioxidant and antitumor activities. In addition, scientific evidence supports their beneficial role in the prevention and management of cardiovascular diseases, which represent the principal focus of the present review. This review provides a comprehensive and detailed analysis of selected nutraceuticals related to the metabolic syndrome, a multifactorial pathological condition characterized by a cluster of metabolic disturbances that collectively increase the risk of developing cardiovascular disease and type 2 diabetes. The metabolic syndrome is typically defined by the presence of abdominal obesity, insulin resistance, hypertension and dyslipidemia, which includes elevated plasma triglyceride levels and decreased concentrations of high-density lipoprotein (HDL) cholesterol. Given the global importance and prevalence of metabolic syndrome, identifying new strategies to treat these disorders, such as the use of nutraceuticals, has become a central focus of biomedical research.

The development of innovative therapeutic strategies for challenging biological targets has led to a resurgence of interest in macrocyclic and peptide-stapled compounds. The conformationally constrained architectures of these compounds enable high affinity, selectivity, and improved pharmacokinetic profiles compared with linear analogues. These properties position macrocycles and stapled-peptides as promising platforms for the development of next-generation therapeutics, including antiviral agents addressing emerging diseases such as COVID-19. In six years, the scientific community has provided several structure-activity relationship studies in which the anti-SARS-CoV-2 effects of macrocycles and stapled-peptides have been reported. The present review aims to discuss macrocycles and stapled-peptides with inhibitory properties against SARS-CoV-2 infection. A particular focus has been addressed to the design of cyclic entities, effect of ring size, presence of unnatural amino acids, stapling position, stereochemistry, role of linkers, pan-antiviral effects, metabolic stability assessment, and selectivity profile, among others. Comparisons with linear counterparts were discussed, wherever applicable, to elucidate the differences in terms of biological properties towards the target, antiviral effects in cell-based assays, molecular architecture, and proteolytic resistance. Overall, the development of macrocycles and stapled-peptides against SARS-CoV-2 was found to be a productive strategy for the identification of novel and effective antiviral agents. Furthermore, future challenges and perspectives have been discussed.

Rhodesain is a cysteine protease that plays a key role in the life cycle of Trypanosoma brucei rhodesiense, an endemic parasite in sub-Saharan Africa and responsible for Human African Trypanosomiasis (HAT), a disease that can be fatal if not treated promptly. Due to the limitations associated with current HAT pharmacological therapy, the search for new targets for the development of antitrypanosomal agents is urgently needed; in this context, rhodesain represents a promising therapeutic target. In this study, new chalcones were synthesized and tested against rhodesain. Given their affinity for the trypanosomal cysteine protease (Ki values in the micromolar range), chalcone 1a was selected to evaluate its effect in combination with the nutraceutical curcumin. The Combination Index (CI) was calculated using Chou and Talalay's method. The analysis of the CI calculated at different fa values of enzyme inhibition for the combination curcumin + 1a showed promising results. For all fa values, the CI is less than one, indicating a synergistic effect when chalcone 1a is combined with curcumin. In particular, at the most significant fa value (0.90), corresponding to 90% of enzyme inhibition, the CI value is 0.1781, indicating a strong synergism between the synthetic drug and the nutraceutical. The combined use of curcumin and chalcone 1a led to an enhancement of rhodesain inhibitory activity, resulting in a strong synergistic effect and supporting further investigation of this combination.

Prostate cancer is the most frequently diagnosed solid-organ malignancy in men worldwide. Metastatic castration-resistant prostate cancer represents a rapidly fatal, end-stage form of the disease for which current therapies remain palliative rather than curative. The advent of chimeric antigen receptor (CAR) T-cell therapy has revolutionized the treatment of refractory hematologic malignancies, and a growing number of studies are now exploring its potential in solid tumors. In this review, we first provide a concise overview of current immunotherapeutic strategies for prostate cancer, including checkpoint inhibitors, vaccine-based approaches, and bispecific antibodies. We then focus on the most recent and promising developments in CAR-T cell therapy for this malignancy. Specifically, we examine the key tumor-associated antigens targeted in prostate cancer-directed CAR-T cell therapy and summarize findings from preclinical research as well as ongoing and completed clinical trials. Finally, we discuss the main challenges that limit the efficacy of CAR-T therapy in prostate cancer, such as antigen heterogeneity, immunosuppressive tumor microenvironments, on-target/off-tumor toxicity, limited T-cell persistence, and inefficient trafficking to metastatic lesions, and outline potential strategies to overcome these barriers. Our aim is to define a translational roadmap for advancing CAR-T therapy toward clinical application in patients with metastatic castration-resistant prostate cancer.

Background: In this study, we report a novel series of proline- and pipecolic acid-based small molecules designed as allosteric inhibitors of the NS2B/NS3 serine proteases from dengue and Zika viruses, key targets in antiviral drug discovery. Results: Enzymatic studies revealed that S-proline derivatives bearing electron-withdrawing substituents on the aromatic ring, particularly that with a trifluoromethyl group in meta position (i.e., compound 3, IC50 = 5.0 µM), were the most potent against DENV NS2B/NS3, while nitro-substituted inhibitors were mostly effective only against the ZIKV protease. R-configured pipecolic acid-based derivatives were the only ones active against DENV NS2B/NS3, even if the mid-micromolar range; however, they demonstrated improved cellular efficacy since inhibitors 24 and 27 exhibiting strong activity in a DENV2 protease reporter gene assay (EC50 = 5.2 and 5.1 µM, respectively). All compounds showed no cytotoxicity (CC50 > 100 µM) and were selective for the viral protease over off-target serine proteases. Structure-based approaches were exploited to map the druggable allosteric site close to Asn152. Conclusions: Our findings led us to identify proline and pipecolic acid-based inhibitors as promising leads for the development of selective flaviviral NS2B/NS3 allosteric inhibitors.

Although conventional medicine has seen substantial progress in recent years, there is a growing interest in nutraceuticals, bioactive compounds derived from natural sources such as plants, fruits, and cereals, due to their potential therapeutic applications. These substances have garnered increasing attention for their capacity to support ocular health and to aid in the prevention and management of age-related eye disorders, including age-related macular degeneration (AMD), cataracts, and glaucoma. This review provides a comprehensive and detailed analysis of selected nutraceuticals related to ocular health and diseases. It aims to define their pharmacodynamic properties, to elucidate the molecular and cellular mechanisms underlying their effects and to critically evaluate the current evidence regarding their potential clinical applications. By integrating findings from both preclinical and clinical studies, this review seeks to offer insights into the role of these nutraceuticals in the prevention, management, and adjunctive treatment of various ocular disorders, thereby suggesting future research directions and clinical practice. Notable attention is given to their antioxidant, anti-inflammatory, and neuroprotective properties, which are believed to contribute to the preservation of visual function and the deceleration of disease progression. Elucidating the medicinal benefits of these compounds may open new pathways for complementary or alternative strategies in the prevention and treatment of ocular diseases.

In this structure-activity relationship (SAR) study, we report the development of rhodesain-targeting peptidomimetics with antitrypanosomal activity. The new compounds (SPR65-SPR80) feature the 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (Tic) moiety as conformationally constrained Phe analog. Various substituents were inserted at the P1 and P3 positions, and the methyl vinyl ketone moiety was introduced as warhead. The incorporation of Tic resulted in reduced affinity against rhodesain compared to the parent compounds containing Phe (2a-m), suggesting that its rigidity negatively affects target binding. Nevertheless, promising EC50 values ranging from 0.42 to 1.35 mu M were observed in cell-based assays, probably due to better pharmacokinetic properties and/or interactions with additional protozoal targets. CC50 values > 100 mu M were observed. Therefore, while Tic is less tolerated by rhodesain, its incorporation in peptidomimetic Michael acceptors led to antitrypanosomal effects that were comparable or slightly better than those of the parent compounds and no cytotoxicity up to 100 mu M. These findings could be taken into consideration in future SAR studies aimed at the development of antitrypanosomal agents.

The name Green Chemistry was coined in 1996 to point out the development of chemical substances and sustainable processes that reduce the formation of toxic products for the environment and humans. The urgent need to bring down the negative effects of the chemical industry to safeguard human health has been the driving force behind green chemistry and the need to respect the United Nations Sustainable Development Goals. This approach allows to increase the effectiveness of synthetic methods, to develop safer, less toxic, and environmentally sustainable chemicals. In this context, microwave-assisted organic reactions revolutionized the chemical synthesis; as a matter of fact, microwave chemistry led to a low environmental impact of the used solvents, and, over the years this overture has become the method of choice in synthetic chemistry. This review highlights in detail the main features of microwaves.

Glioblastoma multiforme (grade IV glioma) is characterized by a high invasive potential, making surgical intervention extremely challenging and patient survival very limited. Current pharmacological approaches show, at best, slight improvements in the therapy against this type of tumor. Microtubules are often the target of antitumoral drugs, and specific drugs affecting their dynamics by acting on microtubule-associated proteins (MAPs) without producing their depolymerization could affect both glioma cell migration/invasion and cell proliferation. Here, we analyzed on a cellular model of glioblastoma multiforme, the effect of a molecule (1-(4-amino-3,5-dimethylphenyl)-3,5-dihydro-7,8-ethylenedioxy-4h2,3-benzodiazepin-4-one, hereafter named 1g) which was shown to act as a cytostatic drug in other cell types by affecting microtubule dynamics. We found that the molecule acts also as a migration suppressor by inducing a loss of cell polarity. We characterized the mechanics of U87MG cell aggregates exposed to 1g by different biophysical techniques. We considered both 3D aggregates and 2D cell cultures, testing substrates of different stiffness. We established that this molecule produces a decrease of cell spheroid contractility and it impairs 3D cell invasion. At the same time, in the case of isolated cells, 1g selectively produces an almost instantaneous loss of cell polarity blocking migration and it also produces a disorganization of the mitotic spindle when cells reach mitosis, leading to frequent mitotic slippage events followed by cell death. We can state that the studied molecule produces similar effects to other molecules that are known to affect the dynamics of microtubules, but probably indirectly via microtubule-associated proteins (MAPs) and following different biochemical pathways. Consistently, we report evidence that, regarding its effect on cell morphology, this molecule shows a specificity for some cell types such as glioma cells. Interestingly, being a molecule derived from a benzodiazepine, the 1g chemical structure could allow this molecule to easily cross the blood–brain barrier. Thanks to its chemical/physical properties, the studied molecule could be a promising new drug for the specific treatment of GBM.

Background/Objectives: Rhodesain is a cysteine protease crucial for the life cycle of Trypanosoma brucei rhodesiense, a parasite that causes the lethal form of human African trypanosomiasis. For these reasons, rhodesain is considered an important target for the drug discovery process of novel antitrypanosomal agents. Methods: In the present work, we carried out a combination study of two novel synthetic nitriles, Nitrile 1 and Nitrile 2, with curcumin, the golden multitarget nutraceutical obtained from Curcuma longa L., which we demonstrated to inhibit rhodesain in a non-competitive manner. We calculated the combination index (CI) in both the combination studies by using the Chou and Talalay method. Results: Comparing the CI values of the combinations Nitrile 1 + curcumin and Nitrile 2 + curcumin, we assessed that the inhibitory effect of the combination Nitrile 2 + curcumin against rhodesain was much more potent than that of the other combination. At the IC50 value, in the case of the combination Nitrile 1 + curcumin an additive effect occurred, while in the case of Nitrile 2 + curcumin, we observed a moderate synergism: at 99% of the effect, the synergism induced by the combination Nitrile 2 + curcumin was much stronger than the synergism promoted by the combination Nitrile 1 + curcumin (CI = 0.3843 vs 0.6622, respectively). Conclusions: The co-administration of dipeptide nitriles with curcumin enhances rhodesain inhibition through synergistic effects. Notably, Nitrile 2 + curcumin exhibits a stronger synergy at higher inhibition levels, indicating a greater therapeutic potential.

Background/Objectives: SARS-CoV-2 pandemic led to the identification of peptide-based main protease (Mpro) inhibitors. The overwhelming majority of them carry an electrophilic warhead and a γ-lactam at the P1 position. During the selectivity assessment of an in-house Michael acceptors targeting SARS-CoV-2 Mpro, we unexpectedly observed a significant inhibition of human cathepsin S (hCatS). Methods: The biological investigation of three compounds (i.e., SPR38, SPR39, and SPR41) against hCatS was performed. The binding mode of SPRs was investigated by docking and molecular dynamics simulations. Results: Biological investigation has corroborated that hCatS is sensitive to peptide-based analogues harbouring γ-lactam at the P1 position and a vinyl methyl ketone warhead. In silico studies revealed that despite being solvent exposed, the γ-lactam at P1 might be involved in water-mediated H-bonds that could be optimized to gain inhibition potency and selectivity. Conclusions: The molecules repurposing of peptide-based SARS-CoV-2 Mpro inhibitors carrying the γ-lactam at the P1 site could pave the way for the identification of novel potent and selective hCatS ligands.

Recently, increasing attention has been directed toward nutraceuticals, natural substances extracted from plants, fruits, or cereals. These compounds are well-known for their antibacterial, anti-inflammatory, antioxidant, and antitumor properties, with the latter being the primary focus of this review. The use of nutraceuticals, both as standalone treatments and in combination with standard chemotherapy, has been extensively studied through in vitro, in vivo experiments, and clinical trials for the prevention and treatment of various types of cancer, including breast, colon, pancreatic, prostate cancers, and leukemia. Findings from these studies emphasize the benefits of nutraceuticals in improving patient compliance and mitigating the adverse effects of conventional drugs. Specifically, the combination of nutraceuticals with chemotherapy allows for reduced dosages of synthetic drugs, thereby lessening their often-severe side effects. In this review, we explore the diverse mechanisms of action underlying the antitumor activity of key nutraceuticals-including curcumin, resveratrol, tocotrienols, ursolic acid, fisetin, gambogic acid, catechins, silibinin, berberine, emodin, piperine, deguelin, garcinol, plumbagin, zerumbone, and ginger. Furthermore, we summarize the most significant outcomes from clinical trials investigating these compounds. The clinical studies addressed various aspects of treatment, such as efficacy, safety, maximum tolerated doses, potential adverse effects, and patient compliance. The majority of the findings highlight the positive impact of combining nutraceuticals with chemotherapy, demonstrating enhanced therapeutic outcomes in anticancer treatments.

Enzymes are biocatalysts that are widespread in living organisms [...]

In the eukaryotic cells, the ubiquitin–proteasome system (UPS) plays a crucial role in the intracellular protein turnover. It is involved in several cellular functions such as the control of the regular cell cycle progression, the immune surveillance, and the homeostasis. Within the 20S proteasome barrel-like structure, the catalytic subunits, β1, β2 and β5, are responsible for different proteolytic activities: caspase-like (C-L), trypsin-like (T-L) and chymotrypsin-like (ChT-L), respectively. The β5 subunit is particularly targeted for its role in antitumor activity: the synthesis of β5 subunit inhibitors could be a promising strategy for the treatment of solid and hematologic tumors. In the present work, we performed two combination studies of AM12, a recently developed synthetic proteasome inhibitor, with curcumin and quercetin, two nutraceuticals endowed of many pharmacological properties. We measured the combination index (CI), applying the Chou and Talalay method, comparing the two studies, from 50% to 90% of proteasome inhibition. In the case of the combination AM12 + curcumin, an increasing synergism was observed from 50% to 90% of proteasome inhibition, while in the case of the combination AM12 + quercetin an additive effect was observed only from 50% to 70% of β5 subunit inhibition. These results suggest that combining AM12 with curcumin is a more promising strategy than combining it with quercetin for potential therapeutic applications, especially in treating tumors.

In recent decades, neglected tropical diseases and poverty-related diseases have become a serious health problem worldwide. Among these pathologies, human African trypanosomiasis, and malaria present therapeutic problems due to the onset of resistance, toxicity problems and the limited spectrum of action. In this drug discovery process, rhodesain and falcipain-2, of Trypanosoma brucei rhodesiense and Plasmodium falciparum, are currently considered the most promising targets for the development of novel antitrypanosomal and antiplasmodial agents, respectively. Therefore, in our study we identified a novel lead-like compound, i.e., inhibitor 2b, which we proved to be active against both targets, with a Ki = 5.06 µM towards rhodesain and an IC50 = 40.43 µM against falcipain-2.

In the global pandemic scenario, dengue and zika viruses (DENV and ZIKV, respectively), both mosquito-borne members of the flaviviridae family, represent a serious health problem, and considering the absence of specific antiviral drugs and available vaccines, there is a dire need to identify new targets to treat these types of viral infections. Within this drug discovery process, the protease NS2B/NS3 is considered the primary target for the development of novel anti-flavivirus drugs. The NS2B/NS3 is a serine protease that has a dual function both in the viral replication process and in the elusion of the innate immunity. To date, two main classes of NS2B/NS3 of DENV and ZIKV protease inhibitors have been discovered: those that bind to the orthosteric site and those that act at the allosteric site. Therefore, this perspective article aims to discuss the main features of the use of the most potent NS2B/NS3 inhibitors and their impact at the social level.

In this structure-activity relationship (SAR) study, we report the development of dual inhibitors with antiviral properties targeting the SARS-CoV-2 main protease (M-pro) and human cathepsin L (hCatL). The novel molecules differ in the aliphatic amino acids at the P2 site and the fluorine position on the phenyl ring at the P3 site. The identified dual inhibitors showed K-i values within 1.61 and 10.72 mu M against SARS-CoV-2 M-pro; meanwhile, K-i values ranging from 0.004 to 0.701 mu M toward hCatL were observed. A great interdependency between the nature of the side chain at the P2 site and the position of the fluorine atom was found. Three dual-targeting inhibitors exhibited antiviral activity in the low micromolar range with CC50 values >100 mu M. Docking simulations were executed to gain a deeper understanding of the SAR profile. The findings herein collected should be taken into consideration for the future development of dual SARS-CoV-2 M-pro/hCatL inhibitors.

Neglected tropical diseases (NTDs) include 20 diverse infections mainly prevalent in tropical areas that mostly affect disadvantaged communities and women and children [...].

Neuroinflammation is an inflammatory response of the nervous tissue mediated by the production of cytokines, chemokines, and reactive oxygen species. Recent studies have shown that an upregulation of immunoproteasome is highly associated with various diseases and its inhibition attenuates neuroinflammation. In this context, the development of non-covalent immunoproteasome-selective inhibitors could represent a promising strategy for treating inflammatory diseases. Novel amide derivatives, KJ3 and KJ9, inhibit the β5 subunit of immunoproteasome and were used to evaluate their possible anti-inflammatory effects in an in vitro model of TNF-α induced neuroinflammation. Differentiated SH-SY5Y and microglial cells were challenged with 10 ng/mL TNF-α for 24 h and treated with KJ3 (1 µM) and KJ9 (1 µM) for 24 h. The amide derivatives showed a significant reduction of oxidative stress and the inflammatory cascade triggered by TNF-α reducing p-ERK expression in treated cells. Moreover, the key action of these compounds on the immunoproteasome was further confirmed by halting the IkB-α phosphorylation and the consequent inhibition of NF-kB. As downstream targets, IL-1β and IL-6 expression resulted also blunted by either KJ3 and KJ9. These preliminary results suggest that the effects of these two compounds during neuroinflammatory response relies on the reduced expression of pro-inflammatory targets.

Despite several major achievements in the development of vaccines and antivirals, the fight against SARS-CoV-2 and the health problems accompanying COVID-19 are still ongoing. SARS-CoV-2 main protease (Mpro), an essential viral cysteine protease, is a crucial target for the development of antiviral agents. A virtual screening analysis of in-house cysteine protease inhibitors against SARS-CoV-2 Mpro allowed us to identify two hits (i.e., 1 and 2) bearing a methyl vinyl ketone warhead. Starting from these compounds, we herein report the development of Michael acceptors targeting SARS-CoV-2 Mpro, which differ from each other for the warhead and for the amino acids at the P2 site. The most promising vinyl methyl ketone-containing analogs showed sub-micromolar activity against the viral protease. SPR38, SPR39, and SPR41 were fully characterized, and additional inhibitory properties towards hCatL, which plays a key role in the virus entry into host cells, were observed. SPR39 and SPR41 exhibited single-digit micromolar EC50 values in a SARS-CoV-2 infection model in cell culture.