Discovery of novel FGF trap small molecules endowed with anti-myeloma activity.

Fibroblast growth factors (FGFs) act as proangiogenic and mitogenic cytokines in several cancers, including multiple myeloma (MM). Indeed, corrupted FGF autocrine and paracrine secretion induces an aberrant activation of the FGF receptor (FGFR) signaling sustaining cancer cell spreading and resistance to pharmacological treatments. Thus, FGF traps may represent a promising anti-cancer strategy to hamper the ligand-dependent activation of the FGF/FGFR system. We previously identified NSC12 as the first orally available small molecule FGF trap able to inhibit the growth and progression of several FGF-dependent tumor models. NSC12 is a pregnenolone derivative carrying a 1,1-bis-trifluoromethyl-1,3-propanediol chain in position 17 of the steroid nucleus. Investigation of structure-activity relationships (SARs) provided more potent and specific NSC12 steroid derivatives and highlighted that the C17-side chain is pivotal for the FGF trap activity. Here, a scaffold hopping approach allowed to obtain two FGF trap compounds (22 and 57) devoid of the steroid nucleus and able to efficiently bind FGF2 and to inhibit FGFR activation in MM cells. Accordingly, these compounds exert a potent anti-tumor activity on MM cell lines both in vitro and in vivo and on MM patient-derived primary cells, strongly affecting the survival of both proteasome-inhibitor sensitive and resistant MM cells. These results propose a new therapeutic option for relapsed/refractory MM patients and set the bases for the development of novel FGF traps prone to chemical diversification to be used in the clinic for the treatment of those tumors in which the FGF/FGFR system plays a pivotal role, including MM.

The influence of cation exchange on the possible mechanism of erionite toxicity: A synchrotron-based micro-X-ray fluorescence study on THP-1-derived macrophages exposed to erionite-Na.

Fibrous erionite is the only zeolite classified as Group 1 carcinogen by the International Agency for Research on Cancer (IARC). Carcinogenesis induced by erionite is thought to involve several factors as biopersistence, the iron role and cation exchange processes. To better understand these mechanisms, a detailed investigation at the micro scale was performed, collecting elemental information on iron and cation release and their distribution in biological systems by synchrotron micro-X-ray fluorescence mapping (SR-micro-XRF) and synchrotron micro-X-ray absorption spectroscopy (SR-micro-XANES) at the TwinMic beamline (Elettra synchrotron) and at the ID21 beamline of the European Synchrotron Radiation Facility (ESRF). By microscopy and chemical mapping, highly detailed maps of the chemical and morphological interaction of biological systems with fibres could be produced. In detail, THP-1 cell line derived macrophages, used as in vitro model, were analysed during erionite-Na phagocytosis at different time intervals, after single dose exposure. For comparison, cellular fluorescent probes were also used to evaluate the intracellular free sodium and calcium concentrations. Synchrotron analyses visualised the spatial distribution of both fibre and mineral particle associated metals during the phagocytosis, describing the mechanism of internalisation of erionite-Na and its accessory mineral phases. The intracellular distribution of metals and other cations was mapped to evaluate metal release, speciation changes and/or cation exchange during phagocytosis. The fluorescent probes complemented microchemical data clarifying, and confirming, the cation distribution observed in the SR-micro-XRF maps. The significant cytoplasmic calcium decrease, and the concomitant sodium increase, after the fibre phagocytosis seemed due to activation of plasma membrane cations exchangers triggered by the internalisation while, surprisingly, the ion-exchange capacity of erionite-Na could play a minor role in the disruption of the two cations intracellular homeostasis. These results help to elucidate the role of cations in the toxicity of erionite-treated THP-1 macrophages and add knowledge to its carcinogenicity process.

The CDK Inhibitor Dinaciclib Improves Cisplatin Response in Nonseminomatous Testicular Cancer: A Preclinical Study.

BACKGROUND: Most patients with testicular germ cell tumors (GCTs) are treated with cisplatin (CP)-based chemotherapy. However, some of them may develop CP resistance and therefore represent a clinical challenge. Cyclin-dependent kinase 5 (CDK5) is involved in chemotherapy resistance in different types of cancer. Here, we investigated the possible role of CDK5 and other CDKs targeted by dinaciclib in nonseminoma cell models (both CP-sensitive and CP-resistant), evaluating the potential of the CDK inhibitor dinaciclib as a single/combined agent for the treatment of advanced/metastatic testicular cancer (TC). METHODS: The effects of dinaciclib and CP on sensitive and resistant NT2/D1 and NCCIT cell viability and proliferation were evaluated using MTT assays and direct count methods. Flow cytometry cell-cycle analysis was performed. The protein expression was assessed via Western blotting. The in vivo experiments were conducted in zebrafish embryos xenografted with TC cells. RESULTS: Among all the CDKs analyzed, CDK5 protein expression was significantly higher in CP-resistant models. Dinaciclib reduced the cell viability and proliferation in each cell model, inducing changes in cell-cycle distribution. In drug combination experiments, dinaciclib enhances the CP effect both in vitro and in the zebrafish model. CONCLUSIONS: Dinaciclib, when combined with CP, could be useful for improving nonseminoma TC response to CP.

An innovative in situ AFM system for a soft X-ray spectromicroscopy synchrotron beamline.

Multimodal imaging and spectroscopy like concurrent scanning transmission X-ray microscopy (STXM) and X-ray fluorescence (XRF) are highly desirable as they allow retrieving complementary information. This paper reports on the design, development, integration and field testing of a novel in situ atomic force microscopy (AFM) instrument for operation under high vacuum in a synchrotron soft X-ray microscopy STXM-XRF end-station. A combination of µXRF and AFM is demonstrated for the first time in the soft X-ray regime, with an outlook for the full XRF-STXM-AFM combination.

Antifungal and Antiproliferative Activity of Pistagremic Acid and Flavonoids Extracted from the Galls of Pistacia chinensis subsp. integerrima.

Pistacia chinensis subsp. integerrima (J.L. Stewart) Rech. f. is a plant known for its therapeutic applications in traditional medicine, which are related to its antimicrobial, anticancer, antioxidant, anti-inflammatory, analgesic, antidiarrheal, and muscle relaxant properties. The galls of P. chinensis are rich in triterpenes and flavonoids, and we here report the extraction of pistagremic acid (1), apigenin (2) and sakuranetin (3) from this source. The isolated compounds were tested against Aspergillus flavus, Candida albicans, Candida glabrata, Fusarium solani, Microsporum canis and Trichoderma longibrachiatum. The results highlighted the antimicrobial activity of flavonoids 2 and 3, suggesting that this class of molecules may be responsible for the effect related to the traditional use. On the other hand, when the compounds and the extract were tested for their antiproliferative activity on a panel of 4 human cancer cell lines, the triterpene pistagremic acid (1) showed a higher potential, thus demonstrating a different bioactivity profile. Structure-based docking and molecular dynamics simulations were used to help the interpretation of experimental results. Taken together, the here reported findings pave the way for the rationalization of the use of P. chinensis extracts, highlighting the contributions of the different components of galls to the observed bioactivity.

Advances in sparse dynamic scanning in spectromicroscopy through compressive sensing.

Scanning microscopies and spectroscopies like X-ray Fluorescence (XRF), Scanning Transmission X-ray Microscopy (STXM), and Ptychography are of very high scientific importance as they can be employed in several research fields. Methodology and technology advances aim at analysing larger samples at better resolutions, improved sensitivities and higher acquisition speeds. The frontiers of those advances are in detectors, radiation sources, motors, but also in acquisition and analysis software together with general methodology improvements. We have recently introduced and fully implemented an intelligent scanning methodology based on compressive sensing, on a soft X-ray microscopy beamline. This demonstrated sparse low energy XRF scanning of dynamically chosen regions of interest in combination with STXM, yielding spectroimaging data in the megapixel-range and in shorter timeframes than were previously not feasible. This research has been further developed and has been applied to scientific applications in biology. The developments are mostly in the dynamic triggering decisional mechanism in order to incorporate modern Machine Learning (ML) but also in the suitable integration of the method in the control system, making it available for other beamlines and imaging techniques. On the applications front, the method was previously successfully used on different samples, from lung and ovarian human tissues to plant root sections. This manuscript introduces the latest methodology advances and demonstrates their applications in life and environmental sciences. Lastly, it highlights the auxiliary development of a mobile application, designed to assist the user in the selection of specific regions of interest in an easy way.

Synthesis, docking studies and biological evaluation of 1H-1,2,3-triazole-7-chloroquinoline derivatives against SARS-CoV-2.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a single-stranded enveloped positive RNA virus and the cause of the ongoing coronavirus disease 2019 (COVID-19) pandemic. Chloroquine (CQ), an antimalarial drug, was reported to be active against several viruses including coronaviruses. The mechanism of host cell invasion by SARS-CoV-2 involves the interaction of angiotensin-converting enzyme (ACE2) with receptor-binding domain (RBD) of spike protein (S). The main protease (Mpro/3CLpro) is an attractive drug target due to its vital function in regulation of polyprotein translated from viral RNA. In this study, a series of novel quinoline-triazole hybrid compounds was synthesized and subjected to evaluations on their cytotoxicity, interactions with different variants of RBD in SARS-CoV-2 and with 3CLpro enzyme by experimental and computational techniques to identify their ability of counteracting viral infection. The results of bio-layer interferometry showed that quinoline derivative 11 has good interaction with delta plus and omicron RBD variants (KD = 3.46 × 10-5 and 6.38 × 10-5 M) while derivative 1 is the best binder for recent variant omicron (KD = 26.9 µM) among the series. Potent compounds 1-4 and 11 also demonstrated a suppressive effect on 3CLpro activity in a non-dose-dependent manner. Further docking study revealed that these compounds interacted within the same area of RBD, while no correlation was found for 3CLpro. Furthermore, the molecular dynamics simulations were carried out to assess the conformational stability of docked complexes for preliminary verification.

Virtual Screening-Accelerated Discovery of a Phosphodiesterase 9 Inhibitor with Neuroprotective Effects in the Kainate Toxicity In Vitro Model.

In the central nervous system, some specific phosphodiesterase (PDE) isoforms modulate pathways involved in neuronal plasticity. Accumulating evidence suggests that PDE9 may be a promising therapeutic target for neurodegenerative diseases. In the current study, computational techniques were used to identify a nature-inspired PDE9 inhibitor bearing the scaffold of an isoflavone, starting from a database of synthetic small molecules using a ligand-based approach. Furthermore, docking studies supported by molecular dynamics investigations allowed us to evaluate the features of the ligand-target complex. In vitro assays confirmed the computational results, showing that the selected compound inhibits the enzyme in the nanomolar range. Additionally, we evaluated the expression of gene and protein levels of PDE9 in organotypic hippocampal slices, observing an increase following exposure to kainate (KA). Importantly, the PDE9 inhibitor reduced CA3 damage induced by KA in a dose-dependent manner in organotypic hippocampal slices. Taken together, these observations strongly support the potential of the identified nature-inspired PDE9 inhibitor and suggest that such a molecule could represent a promising lead compound to develop novel therapeutic tools against neurological diseases..

Morphological and lipid metabolism alterations in macrophages exposed to model environmental nanoplastics traced by high-resolution synchrotron techniques.

The release of nanoplastics (NPs) in the environment is a significant health concern for long-term exposed humans. Although their usage has certainly revolutionized several application fields, at nanometer size, NPs can easily interact at the cellular level, resulting in potential harmful effects. Micro/Nanoplastics (M/NPs) have a demonstrated impact on mammalian endocrine components, such as the thyroid, adrenal gland, testes, and ovaries, while more investigations on prenatal and postnatal exposure are urgently required. The number of literature studies on the NPs' presence in biological samples is increasing. However, only a few offer a close study on the model environmental NP-immune system interaction exploited by advanced microscopy techniques. The present study highlights substantial morphological and lipid metabolism alterations in human M1 macrophages exposed to labeled polypropylene and polyvinyl chloride nanoparticles (PP and PVC NPs) (20 µg/ml). The results are interpreted by advanced microscopy techniques combined with standard laboratory tests and fluorescence microscopy. We report the accurate detection of polymeric nanoparticles doped with cadmium selenide quantum dots (CdSe-QDs NPs) by following the Se (L line) X-ray fluorescence emission peak at higher sub-cellular resolution, compared to the supportive light fluorescence microscopy. In addition, scanning transmission X-ray microscopy (STXM) imaging successfully revealed morphological changes in NP-exposed macrophages, providing input for Fourier transform infrared (FTIR) spectroscopy analyses, which underlined the chemical modifications in macromolecular components, specifically in lipid response. The present evidence was confirmed by quantifying the lipid droplet (LD) contents in PP and PVC NPs-exposed macrophages (0-100 µg/ml) by Oil Red O staining. Hence, even at experimental NPs' concentrations and incubation time, they do not significantly affect cell viability; they cause an evident lipid metabolism impairment, a hallmark of phagocytosis and oxidative stress.

Synthesis and Evaluation of Bithiazole Derivatives As Potential α-Sarcoglycan Correctors.

4'-Methyl-4,5'-bithiazoles were previously identified as cystic fibrosis transmembrane regulator (CFTR) correctors, thus being able to correct folding defective mutants of the channel regulating chloride transport through the membrane. Additionally, bithiazole derivative C17 was reported to recover α-sarcoglycan in vitro and in vivo. We report here the synthesis of two new derivatives of C17, in which the two sides of the bithiazole scaffold were modified. The synthesized compounds and the corresponding precursors were tested in myogenic cells to evaluate the expression of α-sarcoglycan. The results highlighted that both substitutions of the bithiazole scaffold are important to achieve the maximum recovery of the α-sarcoglycan mutant. Nonetheless, partial preservation of the activity was observed. Accordingly, this paves the way to further derivatizations/optimization and target fishing studies, which were preliminarily performed in this study as a proof of concept, allowing the investigation of the molecular mechanisms leading to the α-sarcoglycan correction.

Severity of Hepatocyte Damage and Prognosis in Cirrhotic Patients Correlate with Hepatocyte Magnesium Depletion.

We aimed to evaluate the magnesium content in human cirrhotic liver and its correlation with serum AST levels, expression of hepatocellular injury, and MELDNa prognostic score. In liver biopsies obtained at liver transplantation, we measured the magnesium content in liver tissue in 27 cirrhotic patients (CIRs) and 16 deceased donors with healthy liver (CTRLs) by atomic absorption spectrometry and within hepatocytes of 15 CIRs using synchrotron-based X-ray fluorescence microscopy. In 31 CIRs and 10 CTRLs, we evaluated the immunohistochemical expression in hepatocytes of the transient receptor potential melastatin 7 (TRPM7), a magnesium influx chanzyme also involved in inflammation. CIRs showed a lower hepatic magnesium content (117.2 (IQR 110.5-132.9) vs. 162.8 (IQR 155.9-169.8) µg/g; p < 0.001) and a higher percentage of TRPM7 positive hepatocytes (53.0 (IQR 36.8-62.0) vs. 20.7 (10.7-32.8)%; p < 0.001) than CTRLs. In CIRs, MELDNa and serum AST at transplant correlated: (a) inversely with the magnesium content both in liver tissue and hepatocytes; and (b) directly with the percentage of hepatocytes stained intensely for TRPM7. The latter also directly correlated with the worsening of MELDNa at transplant compared to waitlisting. Magnesium depletion and overexpression of its influx chanzyme TRPM7 in hepatocytes are associated with severity of hepatocyte injury and prognosis in cirrhosis. These data represent the pathophysiological basis for a possible beneficial effect of magnesium supplementation in cirrhotic patients.

The Role of Natural and Semi-Synthetic Compounds in Ovarian Cancer: Updates on Mechanisms of Action, Current Trends and Perspectives.

Ovarian cancer represents a major health concern for the female population: there is no obvious cause, it is frequently misdiagnosed, and it is characterized by a poor prognosis. Additionally, patients are inclined to recurrences because of metastasis and poor treatment tolerance. Combining innovative therapeutic techniques with established approaches can aid in improving treatment outcomes. Because of their multi-target actions, long application history, and widespread availability, natural compounds have particular advantages in this connection. Thus, effective therapeutic alternatives with improved patient tolerance hopefully can be identified within the world of natural and nature-derived products. Moreover, natural compounds are generally perceived to have more limited adverse effects on healthy cells or tissues, suggesting their potential role as valid treatment alternatives. In general, the anticancer mechanisms of such molecules are connected to the reduction of cell proliferation and metastasis, autophagy stimulation and improved response to chemotherapeutics. This review aims at discussing the mechanistic insights and possible targets of natural compounds against ovarian cancer, from the perspective of medicinal chemists. In addition, an overview of the pharmacology of natural products studied to date for their potential application towards ovarian cancer models is presented. The chemical aspects as well as available bioactivity data are discussed and commented on, with particular attention to the underlying molecular mechanism(s).

Automatic Differentiation for Inverse Problems in X-ray Imaging and Microscopy.

Computational techniques allow breaking the limits of traditional imaging methods, such as time restrictions, resolution, and optics flaws. While simple computational methods can be enough for highly controlled microscope setups or just for previews, an increased level of complexity is instead required for advanced setups, acquisition modalities or where uncertainty is high; the need for complex computational methods clashes with rapid design and execution. In all these cases, Automatic Differentiation, one of the subtopics of Artificial Intelligence, may offer a functional solution, but only if a GPU implementation is available. In this paper, we show how a framework built to solve just one optimisation problem can be employed for many different X-ray imaging inverse problems.

An Updated Overview on the Role of Small Molecules and Natural Compounds in the "Young Science" of Rejuvenation.

Aging is a gradual process that occurs over time which leads to a progressive decline of cells and tissues. Telomere shortening, genetic instability, epigenetic alteration, and the accumulation of misfolded proteins represent the main hallmarks that cause perturbed cellular functions; this occurs in conjunction with the progression of the so-called "aging clocks". Rejuvenation aims to influence the natural evolution of such aging clocks and to enhance regenerative capacity, thus overcoming the limitations of common anti-aging interventions. Current rejuvenation processes are based on heterochronic parabiosis, cell damage dilution through asymmetrical cell division, the excretion of extracellular vesicles, the modulation of genetic instability involving G-quadruplexes and DNA methylation, and cell reprogramming using Yamanaka factors and the actions of antioxidant species. In this context, we reviewed the most recent contributions that report on small molecules acting as senotherapeutics; these molecules act by promoting one or more of the abovementioned processes. Candidate drugs and natural compounds that are being studied as potential rejuvenation therapies act by interfering with CDGSH iron-sulfur domain 2 (CISD2) expression, G-quadruplex structures, DNA methylation, and mitochondrial decay. Moreover, direct and indirect antioxidants have been reported to counteract or revert aging through a combination of mixed mechanisms.

Impact of Sample Preparation Methods on Single-Cell X-ray Microscopy and Light Elemental Analysis Evaluated by Combined Low Energy X-ray Fluorescence, STXM and AFM.

BACKGROUND: Although X-ray fluorescence microscopy is becoming a widely used technique for single-cell analysis, sample preparation for this microscopy remains one of the main challenges in obtaining optimal conditions for the measurements in the X-ray regime. The information available to researchers on sample treatment is inadequate and unclear, sometimes leading to wasted time and jeopardizing the experiment's success. Many cell fixation methods have been described, but none of them have been systematically tested and declared the most suitable for synchrotron X-ray microscopy. METHODS: The HEC-1-A endometrial cells, human spermatozoa, and human embryonic kidney (HEK-293) cells were fixed with organic solvents and cross-linking methods: 70% ethanol, 3.7%, and 2% paraformaldehyde; in addition, HEK-293 cells were subjected to methanol/ C3H6O treatment and cryofixation. Fixation methods were compared by coupling low-energy X-ray fluorescence with scanning transmission X-ray microscopy and atomic force microscopy. RESULTS: Organic solvents lead to greater dehydration of cells, which has the most significant effect on the distribution and depletion of diffusion elements. Paraformaldehyde provides robust and reproducible data. Finally, the cryofixed cells provide the best morphology and element content results. CONCLUSION: Although cryofixation seems to be the most appropriate method as it allows for keeping cells closer to physiological conditions, it has some technical limitations. Paraformaldehyde, when used at the average concentration of 3.7%, is also an excellent alternative for X-ray microscopy.

Solid-State Fermentation of Trichoderma spp.: A New Way to Valorize the Agricultural Digestate and Produce Value-Added Bioproducts.

In this study, the agricultural digestate from anaerobic biogas production mixed with food wastes was used as a substrate to grow Trichoderma reesei RUT-C30 and Trichoderma atroviride Ta13 in solid-state fermentation (SSF) and produce high-value bioproducts, such as bioactive molecules to be used as ingredients for biostimulants. The Trichoderma spp. reached their maximum growth after 6 and 3 SSF days, respectively. Both Trichoderma species were able to produce cellulase, esterase, and citric and malic acids, while T. atroviride also produced gibberellins and oxylipins as shown by ultraperformance liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) profiling. Experimental evaluation of germination parameters highlighted a significant promotion of tomato seed germination and root elongation induced by T. atroviride crude extracts from SSF. This study suggests an innovative sustainable use of the whole digestate mixed with agro-food waste as a valuable substrate in fungal biorefineries. Here, it has been applied to produce plant growth-promoting fungi and bioactive molecules for sustainable agriculture.

Soft X-ray Fluorescence and Near-Edge Absorption Microscopy for Investigating Metabolic Features in Biological Systems: A Review.

Scanning transmission X-ray microscopy (STXM) provides the imaging of biological specimens allowing the parallel collection of localized spectroscopic information by X-ray fluorescence (XRF) and/or X-ray Absorption Near Edge Spectroscopy (XANES). The complex metabolic mechanisms which can take place in biological systems can be explored by these techniques by tracing even small quantities of the chemical elements involved in the metabolic pathways. Here, we present a review of the most recent publications in the synchrotrons' scenario where soft X-ray spectro-microscopy has been employed in life science as well as in environmental research.

Morphological and Chemical Investigation of Ovarian Structures in a Bovine Model by Contrast-Enhanced X-ray Imaging and Microscopy.

An improved understanding of an ovary's structures is highly desirable to support advances in folliculogenesis knowledge and reproductive medicine, with particular attention to fertility preservation options for prepubertal girls with malignant tumors. Although currently the golden standard for structural analysis is provided by combining histological sections, staining, and visible 2D microscopic inspection, synchrotron radiation phase-contrast microtomography is becoming a new challenge for three-dimensional studies at micrometric resolution. To this aim, the proper use of contrast agents can improve the visualization of internal structures in ovary tissues, which normally present a low radiopacity. In this study, we report a comparison of four staining protocols, based on iodine or tungsten containing agents, applied to bovine ovarian tissues fixed in Bouin's solution. The microtomography (microCT) analyses at two synchrotron facilities under different set-ups were performed at different energies in order to maximize the image contrast. While tungsten-based agents allow large structures to be well identified, Iodine ones better highlight smaller features, especially when acquired above the K-edge energy of the specific metal. Further scans performed at lower energy where the setup was optimized for overall quality and sensitivity from phase-contrast still provided highly resolved visualization of follicular and intrafollicular structures at different maturation stages, independent of the staining protocol. The analyses were complemented by X-ray Fluorescence mapping on 2D sections, showing that the tungsten-based agent has a higher penetration in this type of tissues.

Multidimensional Profiling of Human Body Hairs Using Qualitative and Semi-Quantitative Approaches with SR-XRF, ATR-FTIR, DSC, and SEM-EDX.

This study aimed to assess the potential of a multidimensional approach to differentiate body hairs based on their physico-chemical properties and whether body hairs can replace the use of scalp hair in studies linked to forensic and systemic intoxication. This is the first case report controlling for confounding variables to explore the utility of multidimensional profiling of body hair using synchrotron synchrotron microbeam X-ray fluorescence (SR-XRF) for longitudinal and hair morphological region mapping) and benchtop methods, including attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) (complemented with chemometrics analysis), energy dispersive X-ray analysis (EDX) (complemented with heatmap analysis), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM) analysis (complemented by descriptive statistics) to profile different body hairs in terms of their elemental, biochemical, thermal, and cuticle properties. This multidimensional approach provided supportive information to emphasize the intricate and rather complex interplay between the organization and levels of elements and biomolecules within the crystalline and amorphous matrix of different body hairs responsible for the differences in physico-chemical properties between body hairs that are predominantly affected by the growth rate, follicle or apocrine gland activity, and external factors such as cosmetic use and exposure to environmental xenobiotics. The data from this study may have important implications for forensic science, toxicology and systemic intoxication, or other studies involving hair as a research matrix.

The Bright Side of Psychedelics: Latest Advances and Challenges in Neuropharmacology.

The need to identify effective therapies for the treatment of psychiatric disorders is a particularly important issue in modern societies. In addition, difficulties in finding new drugs have led pharmacologists to review and re-evaluate some past molecules, including psychedelics. For several years there has been growing interest among psychotherapists in psilocybin or lysergic acid diethylamide for the treatment of obsessive-compulsive disorder, of depression, or of post-traumatic stress disorder, although results are not always clear and definitive. In fact, the mechanisms of action of psychedelics are not yet fully understood and some molecular aspects have yet to be well defined. Thus, this review aims to summarize the ethnobotanical uses of the best-known psychedelic plants and the pharmacological mechanisms of the main active ingredients they contain. Furthermore, an up-to-date overview of structural and computational studies performed to evaluate the affinity and binding modes to biologically relevant receptors of ibogaine, mescaline, N,N-dimethyltryptamine, psilocin, and lysergic acid diethylamide is presented. Finally, the most recent clinical studies evaluating the efficacy of psychedelic molecules in some psychiatric disorders are discussed and compared with drugs already used in therapy.