Toxicity of New Psychoactive Substance (NPS): Threo-4-methylmethylphenidate (4-Mmph) - Prediction of toxicity using in silico methods.

This study represents the first application of in silico methods to evaluate the toxicity of 4-methylphenidate (4-Mmph), a new psychoactive substance (NPS). Using advanced in silico toxicology tools, it was feasible to anticipate key aspects of 4-Mmph's toxicological profile, including acute toxicity (LD50), genotoxicity, cardiotoxicity, and possible endocrine disruption. The findings indicate significant acute toxicity with variability among species, a high potential for adverse effects in the gastrointestinal system and lungs, a low genotoxic potential, a significant likelihood of skin irritation, and a notable cardiotoxicity risk associated with hERG channel inhibition. Evaluation of endocrine disruption revealed a low likelihood that 4-Mmph interacts with the estrogen receptor alpha (ER-α), indicating minimal estrogenic activity. These insights, derived from in silico studies, play a crucial role in improving the comprehension of 4-Mmph in forensic and clinical toxicology. These initial toxicological inquiries establish the foundation for future investigations and help formulate risk assessment and management strategies regarding the use and abuse of NPS. This article is part of a larger project funded by the Polish Ministry of Education and Science, titled "Toxicovigilance, Poisoning Prevention, and First Aid in Poisoning with Xenobiotics of Current Clinical Importance in Poland" (Grant Number SKN/SP/570184/2023).

Toxicovigilance 2.0 - modern approaches for the hazard identification and risk assessment of toxicants in human beings: A review.

The attempt to define toxicovigilance can be based on defining its fundamental principles: prevention of infections with toxic substances, collecting information on poisonings, both in terms of their sources and side effects, and confirming poisonings, with the aim of improving treatment. Substances referred to include both those originating from animal bites, ingested inadvertently, and those resulting from environmental poisoning in industrial regions of countries, etc. In this review, we provide information about the crucial function of poison control centres in toxicovigilance, the importance of incorporating big data analytics and artificial intelligence to streamline toxicovigilance processes, and examples of toxicovigilance in different countries. In conclusion, we will present the direction that modern toxicovigilance should take, incorporating available artificial intelligence methods to maximise efficiency.

Antidotes in Clinical Toxicology-Critical Review.

Poisoning and overdose are very important aspects in medicine and toxicology. Chemical weapons pose a threat to civilians, and emergency medicine principles must be followed when dealing with patients who have been poisoned or overdosed. Antidotes have been used for centuries and modern research has led to the development of new antidotes that can accelerate the elimination of toxins from the body. Although some antidotes have become less relevant due to modern intensive care techniques, they can still save lives or reduce the severity of toxicity. The availability of antidotes is crucial, especially in developing countries where intensive care facilities may be limited. This article aims to provide information on specific antidotes, their recommended uses, and potential risks and new uses. In the case of poisoning, supportive therapies are most often used; however, in many cases, the administration of an appropriate antidote saves the patient's life. In this review, we reviewed the literature on selected antidotes used in the treatment of poisonings. We also characterised the antidotes (bio)chemically. We described the cases in which they are used together with the dosage recommendations. We also analysed the mechanisms of action. In addition, we described alternative methods of using a given substance as a drug, an example of which is N-acetylcysteine, which can be used in the treatment of COVID-19. This article was written as part of the implementation of the project of the Polish Ministry of Education and Science, "Toxicovigilance, poisoning prevention, and first aid in poisoning with xenobiotics of current clinical importance in Poland", grant number SKN/SP/570184/2023.

Design, Synthesis and Activity of New N1-Alkyl Tryptophan Functionalized Dendrimeric Peptides against Glioblastoma.

BACKGROUND: Due to resistance to conventional therapy, a blood-brain barrier that results in poor drug delivery, and a high potential for metastasis, glioblastoma (GBM) presents a great medical challenge. Since the repertoire of the possible therapies is very limited, novel therapeutic strategies require new drugs as well as new approaches. The multiple roles played by L-tryptophan (Trp) in tumorigenesis of GBM and the previously found antiproliferative properties of Trp-bearing dendrimers against this malignancy prompted us to design novel polyfunctional peptide-based dendrimers covalently attached to N1-alkyl tryptophan (Trp) residues. Their antiproliferative properties against GBM and normal human astrocytes (NHA) and their antioxidant potential were tested. METHODS: Two groups of amphiphilic peptide dendrimers terminated with N1-butyl and N1-aminopentane tryptophan were designed. The influence of dendrimers on viability of NHA and human GBM cell lines, displaying different genetic backgrounds and tumorigenic potentials, was determined by the MTT test. The influence of compounds on the clonogenic potential of GBM cells was assessed by colony-formation assay. Dendrimers were tested for radical scavenging potency as well as redox capability (DPPH, ABTS, and FRAP models). RESULTS: Several peptide dendrimers functionalized with N1-alkyl-tryptophan at 5 µM concentration exhibited high selectivity towards GBM cells retaining 85-95% viable NHA cells while killing cancer cells. In both the MTT and colony-formation assays, compounds 21 (functionalized with N1-butyl-Trp and (+)8 charged) and 25 (functionalized with N1-aminopentane-Trp and (+)12 charged) showed the most promise for their development into anticancer drugs. According to ABTS, DPPH, and FRAP antioxidant tests, dendrimers functionalized with N1-alkylated Trp expressed higher ROS-scavenging capacity (ABTS and DPPH) than those with unsubstituted Trp. CONCLUSIONS: Peptide dendrimers functionalized with N1-alkyl-tryptophan showed varying toxicity to NHA, while all were toxic to GBM cells. Based on their activity towards inhibition of GBM viability and relatively mild effect on NHA cells the most advantageous were derivatives 21 and 25 with the respective di-dodecyl and dodecyl residue located at the C-terminus. As expected, peptide dendrimers functionalized with N1-alkyl-tryptophan expressed higher scavenging potency against ROS than dendrimers with unsubstituted tryptophan.

Peptide Dendrimers with Non-Symmetric Bola Structure Exert Long Term Effect on Glioblastoma and Neuroblastoma Cell Lines.

BACKGROUND: Glioblastoma (GBM) is the most common malignant tumor of the central nervous system (CNS). Neuroblastoma (NB) is one of the most common cancers of childhood derived from the neural crest cells. The survival rate for patients with GBM and high-risk NB is poor; therefore, novel therapeutic approaches are needed. Increasing evidence suggests a dual role of redox-active compounds in both tumorigenesis and cancer treatment. Therefore, in this study, polyfunctional peptide-based dendrimeric molecules of the bola structure carrying residues with antiproliferative potential on one side and the antioxidant residues on the other side were designed. METHODS: We synthesized non-symmetric bola dendrimers and assessed their radical scavenging potency as well as redox capability. The influence of dendrimers on viability of rat primary cerebellar neurons (CGC) and normal human astrocytes (NHA) was determined by propidium iodide staining and cell counting. Cytotoxicity against human GBM cell lines, T98G and LN229, and NB cell line SH-SY5Y was assessed by cell counting and colony forming assay. RESULTS: Testing of CGC and NHA viability allowed to establish a range of optimal dendrimers structure and concentration for further evaluation of their impact on two human GBM and one human NB cell lines. According to ABTS, DPPH, FRAP, and CUPRAC antioxidant tests, the most toxic for normal cells were dendrimers with high charge and an excess of antioxidant residues (Trp and PABA) on both sides of the bola structure. At 5 µM concentration, most of the tested dendrimers neither reduced rat CGC viability below 50-40%, nor harmed human neurons (NHA). The same dose of compounds 16 or 22, after 30 min treatment decreased the number of SH-SY5Y and LN229 cells, but did not affect the number of T98G cells 48 h post treatment. However, either compound significantly reduced the number of colonies formed by SH-SY5Y, LN229, and T98G cells measured 14 days after treatment. CONCLUSIONS: Peptide dendrimers with non-symmetric bola structure are excellent scaffolds for design of molecules with pro/antioxidant functionality. Design of molecules with an excess of positive charges and antioxidant residues rendered molecules with high neurotoxicity. Single, 30 min exposition of the GBM and NB cell lines to the selected bola dendrimers significantly suppressed their clonogenic potential.

Discovery of a series of ester-substituted NLRP3 inflammasome inhibitors.

The NLRP3 inflammasome is a component of the innate immune system involved in the production of proinflammatory cytokines. Aberrant activation by a wide range of exogenous and endogenous signals can lead to chronic, low-grade inflammation. It has attracted a great deal of interest as a drug target due to the association with diseases of large unmet medical need such as Alzheimer's disease, Parkinson's disease, arthritis, and cancer. To date, no drugs specifically targeting inhibition of the NLRP3 inflammasome have been approved. In this work, we used the known NLRP3 inflammasome inhibitor CP-456,773 (aka CRID3 or MCC 950) as our starting point and undertook a Structure-Activity Relationship (SAR) analysis and subsequent scaffold-hopping exercise. This resulted in the rational design of a series of novel ester-substituted urea compounds that are highly potent and selective NLRP3 inflammasome inhibitors, as exemplified by compounds 44 and 45. It is hypothesized that the ester moiety acts as a highly permeable delivery vehicle and is subsequently hydrolyzed to the carboxylic acid active species by carboxylesterase enzymes. These molecules are greatly differentiated from the state-of-the-art and offer potential in the treatment of NLRP3-driven diseases, particularly where tissue penetration is required.

Molecular Antioxidant Properties and In Vitro Cell Toxicity of the p-Aminobenzoic Acid (PABA) Functionalized Peptide Dendrimers.

BACKGROUND: Exposure to ozone level and ultraviolet (UV) radiation is one of the major concerns in the context of public health. Numerous studies confirmed that abundant free radicals initiate undesired processes, e.g. carcinogenesis, cells degeneration, etc. Therefore, the design of redox-active molecules with novel structures, containing radical quenchers molecules with novel structures, and understanding their chemistry and biology, might be one of the prospective solutions. Methods: We designed a group of peptide dendrimers carrying multiple copies of p-aminobenzoic acid (PABA) and evaluated their molecular antioxidant properties in 1,1'-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) tests. Cytotoxicity against human melanoma and fibroblast cells as well as against primary cerebral granule cells (CGC) alone and challenged by neurotoxic sodium glutamate and production of reactive oxygen species (ROS) in presence of dendrimers were measured. Results: PABA-terminated dendrimers express enhanced radical and radical cation scavenging properties in relation to PABA alone. In cellular tests, the dendrimers at 100 M fully suppress and between 20⁻100 M reduce proliferation of the human melanoma cell line. In concentration 20 M dendrimers generate small amount of the reactive oxygen species (<25%) but even in their presence human fibroblast and mouse cerebellar granule cells remain intact Moreover, dendrimers at 0.2⁻20 µM concentration (except one) increased the percentage of viable fibroblasts and CGC cells treated with 100 M glutamate. Conclusions: Designed PABA-functionalized peptide dendrimers might be a potential source of new antioxidants with cationic and neutral radicals scavenging potency and/or new compounds with marked selectivity against human melanoma cell or glutamate-stressed CGC neurons. The scavenging level of dendrimers depends strongly on the chemical structure of dendrimer and the presence of other groups that may be prompted into radical form. The present studies found different biological properties for dendrimers constructed from the same chemical fragments but the differing structure of the dendrimer tree provides once again evidence that the structure of dendrimer can have a significant impact on drug⁻target interactions.

Synthesis of amide and sulfonamide substituted N-aryl 6-aminoquinoxalines as PFKFB3 inhibitors with improved physicochemical properties.

In oncology, the "Warburg effect" describes the elevated production of energy by glycolysis in cancer cells. The ubiquitous and hypoxia-induced 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) plays a noteworthy role in the regulation of glycolysis by producing fructose-2,6-biphosphate (F-2,6-BP), a potent activator of the glycolysis rate-limiting phosphofructokinase PFK-1. Series of amides and sulfonamides derivatives based on a N-aryl 6-aminoquinoxaline scaffold were synthesized and tested for their inhibition of PFKFB3 in vitro in a biochemical assay as well as in HCT116 cells. The carboxamide series displayed satisfactory kinetic solubility and metabolic stability, and within this class, potent lead compounds with low nanomolar activity have been identified with a suitable profile for further in vivo evaluation.

Discovery and Structure-Activity Relationships of N-Aryl 6-Aminoquinoxalines as Potent PFKFB3 Kinase Inhibitors.

Energy and biomass production in cancer cells are largely supported by aerobic glycolysis in what is called the Warburg effect. The process is regulated by key enzymes, among which phosphofructokinase PFK-2 plays a significant role by producing fructose-2,6-biphosphate; the most potent activator of the glycolysis rate-limiting step performed by phosphofructokinase PFK-1. Herein, the synthesis, biological evaluation and structure-activity relationship of novel inhibitors of 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3), which is the ubiquitous and hypoxia-induced isoform of PFK-2, are reported. X-ray crystallography and docking were instrumental in the design and optimisation of a series of N-aryl 6-aminoquinoxalines. The most potent representative, N-(4-methanesulfonylpyridin-3-yl)-8-(3-methyl-1-benzothiophen-5-yl)quinoxalin-6-amine, displayed an IC50 of 14 nm for the target and an IC50 of 0.49 µm for fructose-2,6-biphosphate production in human colon carcinoma HCT116 cells. This work provides a new entry in the field of PFKFB3 inhibitors with potential for development in oncology.

Bioinspired Amphiphilic Peptide Dendrimers as Specific and Effective Compounds against Drug Resistant Clinical Isolates of E. coli.

Evolution-derived natural compounds have been inspirational for design of numerous pharmaceuticals, e.g., penicillins and tetracyclines. Herein, we present a bioinspired strategy to design peptide dendrimers for the effective therapy of E. coli infections where the selection of appropriate amino acids and the mode of their assembly are based on the information gained from research on membranolytic natural antimicrobial peptides (AMP's). On the molecular level two opposite effects were explored: the effect of multiple positive charges necessary for membrane disintegration was equilibrated by the anchoring role of tryptophanes. Indeed, a series of Trp-terminated dendrimers exhibited high potency against clinical isolates of antibiotic resistant ESBL E. coli strains, stability in human plasma along with very low hemo- and genotoxicity. Investigation of the underlying antimicrobial mechanism indicated that the dendrimers studied at minimal inhibitory concentration showed weak permeability toward membranes. Solid-state 2D NMR studies revealed their presence on and inside the model membranes. Therefore, their biological properties might be explained by targeting of extra- or intracellular receptors. Our results point to a new approach to design novel branched antimicrobials with high therapeutic index.

Novel dendrimeric lipopeptides with antifungal activity.

A series of new cationic lipopeptides containing branched, amphiphilic polar head derived from (Lys)Lys(Lys) dendron and C(8) or C(12) chain at C-end were designed, synthesized and characterized. Antimicrobial in vitro activity expressed as minimal inhibitory concentration (MIC) was evaluated against Gram-positive and Gram-negative bacteria and yeasts from the Candida genus. A significant enhancement of antimicrobial potency along with increased selectivity against Candida reference strains was detected for derivatives with the C(12) residue. Several compounds were characterized by a low hemotoxicity. The antifungal activity of branched lipopeptides is multimodal and concentration dependent. Several compounds, studied in detail, induced potassium leakage from fungal cells, caused morphological alterations of fungal cells and inhibited activity of candidal ß(1,3)-glucan synthase.