Toxicity of the New Psychoactive Substance (NPS) Clephedrone (4-Chloromethcathinone, 4-CMC): Prediction of Toxicity Using In Silico Methods for Clinical and Forensic Purposes.

This study reports the first application of in silico methods to assess the toxicity of 4-chloromethcathinone (4-CMC), a novel psychoactive substance (NPS). Employing advanced toxicology in silico tools, it was possible to predict crucial aspects of the toxicological profile of 4-CMC, including acute toxicity (LD50), genotoxicity, cardiotoxicity, and its potential for endocrine disruption. The obtained results indicate significant acute toxicity with species-specific variability, moderate genotoxic potential suggesting the risk of DNA damage, and a notable cardiotoxicity risk associated with hERG channel inhibition. Endocrine disruption assessment revealed a low probability of 4-CMC interacting with estrogen receptor alpha (ER-α), suggesting minimal estrogenic activity. These insights, derived from in silico studies, are critical in advancing the understanding of 4-CMC properties in forensic and clinical toxicology. These initial toxicological findings provide a foundation for future research and aid in the formulation of risk assessment and management strategies in the context of the use and abuse of NPSs.

Effect of Xanthohumol, a Bioactive Natural Compound from Hops, on Adenosine Pathway in Rat C6 Glioma and Human SH-SY5Y Neuroblastoma Cell Lines.

Xanthohumol (Xn) is an antioxidant flavonoid mainly extracted from hops (Humulus lupulus), one of the main ingredients of beer. As with other bioactive compounds, their therapeutic potential against different diseases has been tested, one of which is Alzheimer's disease (AD). Adenosine is a neuromodulatory nucleoside that acts through four different G protein-coupled receptors: A1 and A3, which inhibit the adenylyl cyclases (AC) pathway, and A2A and A2B, which stimulate this activity, causing either a decrease or an increase, respectively, in the release of excitatory neurotransmitters such as glutamate. This adenosinergic pathway, which is altered in AD, could be involved in the excitotoxicity process. Therefore, the aim of this work is to describe the effect of Xn on the adenosinergic pathway using cell lines. For this purpose, two different cellular models, rat glioma C6 and human neuroblastoma SH-SY5Y, were exposed to a non-cytotoxic 10 µM Xn concentration. Adenosine A1 and A2A, receptor levels, and activities related to the adenosine pathway, such as adenylate cyclase, protein kinase A, and 5'-nucleotidase, were analyzed. The adenosine A1 receptor was significantly increased after Xn exposure, while no changes in A2A receptor membrane levels or AC activity were reported. Regarding 5'-nucleotidases, modulation of their activity by Xn was noted since CD73, the extracellular membrane attached to 5'-nucleotidase, was significantly decreased in the C6 cell line. In conclusion, here we describe a novel pathway in which the bioactive flavonoid Xn could have potentially beneficial effects on AD as it increases membrane A1 receptors while modulating enzymes related to the adenosine pathway in cell cultures.

Xanthohumol Promotes Skp2 Ubiquitination Leading to the Inhibition of Glycolysis and Tumorigenesis in Ovarian Cancer.

Ovarian cancer is a common, highly lethal tumor. Herein, we reported that S-phase kinase-associated protein 2 (Skp2) is essential for the growth and aerobic glycolysis of ovarian cancer cells. Skp2 was upregulated in ovarian cancer tissues and associated with poor clinical outcomes. Using a customized natural product library screening, we found that xanthohumol inhibited aerobic glycolysis and cell viability of ovarian cancer cells. Xanthohumol facilitated the interaction between E3 ligase Cdh1 and Skp2 and promoted the Ub-K48-linked polyubiquitination of Skp2 and degradation. Cdh1 depletion reversed xanthohumol-induced Skp2 downregulation, enhancing HK2 expression and glycolysis in ovarian cancer cells. Finally, a xenograft tumor model was employed to examine the antitumor efficacy of xanthohumol in vivo. Collectively, we discovered that xanthohumol promotes the binding between Skp2 and Cdh1 to suppress the Skp2/AKT/HK2 signal pathway and exhibits potential antitumor activity for ovarian cancer cells.

Antitumor Effect and Gut Microbiota Modulation by Quercetin, Luteolin, and Xanthohumol in a Rat Model for Colorectal Cancer Prevention.

Colorectal cancer stands as the third most prevalent form of cancer worldwide, with a notable increase in incidence in Western countries, mainly attributable to unhealthy dietary habits and other factors, such as smoking or reduced physical activity. Greater consumption of vegetables and fruits has been associated with a lower incidence of colorectal cancer, which is attributed to their high content of fiber and bioactive compounds, such as flavonoids. In this study, we have tested the flavonoids quercetin, luteolin, and xanthohumol as potential antitumor agents in an animal model of colorectal cancer induced by azoxymethane and dodecyl sodium sulphate. Forty rats were divided into four cohorts: Cohort 1 (control cohort), Cohort 2 (quercetin cohort), Cohort 3 (luteolin cohort), and Cohort 4 (xanthohumol cohort). These flavonoids were administered intraperitoneally to evaluate their antitumor potential as pharmaceutical agents. At the end of the experiment, after euthanasia, different physical parameters and the intestinal microbiota populations were analyzed. Luteolin was effective in significantly reducing the number of tumors compared to the control cohort. Furthermore, the main significant differences at the microbiota level were observed between the control cohort and the cohort treated with luteolin, which experienced a significant reduction in the abundance of genera associated with disease or inflammatory conditions, such as Clostridia UCG-014 or Turicibacter. On the other hand, genera associated with a healthy state, such as Muribaculum, showed a significant increase in the luteolin cohort. These results underline the anti-colorectal cancer potential of luteolin, manifested through a modulation of the intestinal microbiota and a reduction in the number of tumors.

Xanthohumol, a prenylated chalcone, regulates lipid metabolism by modulating the LXRα/RXR-ANGPTL3-LPL axis in hepatic cell lines and high-fat diet-fed zebrafish models.

Angiopoietin-like 3 (ANGPTL3) acts as an inhibitor of lipoprotein lipase (LPL), impeding the breakdown of triglyceride-rich lipoproteins (TGRLs) in circulation. Targeting ANGPTL3 is considered a novel strategy for improving dyslipidemia and atherosclerotic cardiovascular diseases (ASCVD). Hops (Humulus lupulus L.) contain several bioactive prenylflavonoids, including xanthohumol (Xan), isoxanthohumol (Isoxan), 6-prenylnaringenin (6-PN), and 8-prenylnaringenin (8-PN), with the potential to manage lipid metabolism. The aim of this study was to investigate the lipid-lowering effects of Xan, the effective prenylated chalcone in attenuating ANGPTL3 transcriptional activity, both in vitro using hepatic cells and in vivo using zebrafish models, along with exploring the underlying mechanisms. Xan (10 and 20 µM) significantly reduced ANGPTL3 mRNA and protein expression in HepG2 and Huh7 cells, leading to a marked decrease in secreted ANGPTL3 proteins via hepatic cells. In animal studies, orally administered Xan significantly alleviated plasma triglyceride (TG) and cholesterol levels in zebrafish fed a high-fat diet. Furthermore, it reduced hepatic ANGPTL3 protein levels and increased LPL activity in zebrafish models, indicating its potential to modulate lipid profiles in circulation. Furthermore, molecular docking results predicted that Xan exhibits a higher binding affinity to interact with liver X receptor α (LXRα) and retinoic acid X receptor (RXR) than their respective agonists, T0901317 and 9-Cis-retinoic acid (9-Cis-RA). We observed that Xan suppressed hepatic ANGPTL3 expression by antagonizing the LXRα/RXR-mediated transcription. These findings suggest that Xan ameliorates dyslipidemia by modulating the LXRα/RXR-ANGPTL3-LPL axis. Xan represents a novel potential inhibitor of ANGPTL3 for the prevention or treatment of ASCVD.

Xanthohumol-A Miracle Molecule with Biological Activities: A Review of Biodegradable Polymeric Carriers and Naturally Derived Compounds for Its Delivery.

Xanthohumol (Xn), a prenylated chalcone found in Hop (Humulus lupulus L.), has been shown to have potent anti-aging, diabetes, inflammation, microbial infection, and cancer properties. Unfortunately, this molecule has undesirable characteristics such as inadequate intake, low aqueous solubility, and a short half-life. To address these drawbacks, researchers have made numerous attempts to improve its absorption, solubility, and bioavailability. Polymeric drug delivery systems (PDDSs) have experienced significant development over the last two decades. Polymeric drug delivery is defined as a formulation or device that allows the introduction of a therapeutic substance into the body. Biodegradable and bioreducible polymers are the ideal choice for a variety of new DDSs. Xn formulations based on biodegradable polymers and naturally derived compounds could solve some of the major drawbacks of Xn-based drug delivery. In this regard, the primary concern of this study is on presenting innovative formulations for Xn delivery, such as nanoparticles (NPs), nanomicelles, nanoliposomes, solid lipid nanoparticles (SLNs), and others, as well as the received in vitro and in vivo data. Furthermore, this work describes the chemistry and broad biological activity of Xn, which is particularly useful in modern drug technology as well as the cosmetics industry. It is also important to point out that the safety of using Xn, and its biotransformation, pharmacokinetics, and clinical applications, have been thoroughly explained in this review.

Gut enterotype-dependent modulation of gut microbiota and their metabolism in response to xanthohumol supplementation in healthy adults.

Xanthohumol (XN), a polyphenol found in the hop plant (Humulus lupulus), has antioxidant, anti-inflammatory, prebiotic, and anti-hyperlipidemic activity. Preclinical evidence suggests the gut microbiome is essential in mediating these bioactivities; however, relatively little is known about XN's impact on human gut microbiota in vivo. We conducted a randomized, triple-blinded, placebo-controlled clinical trial (ClinicalTrials.gov NCT03735420) to determine safety and tolerability of XN in healthy adults. Thirty healthy participants were randomized to 24 mg/day XN or placebo for 8 weeks. As secondary outcomes, quantification of bacterial metabolites and 16S rRNA gene sequencing were utilized to explore the relationships between XN supplementation, gut microbiota, and biomarkers of gut health. Although XN did not significantly change gut microbiota composition, it did re-shape individual taxa in an enterotype-dependent manner. High levels of inter-individual variation in metabolic profiles and bioavailability of XN metabolites were observed. Moreover, reductions in microbiota-derived bile acid metabolism were observed, which were specific to Prevotella and Ruminococcus enterotypes. These results suggest interactions between XN and gut microbiota in healthy adults are highly inter-individualized and potentially indicate that XN elicits effects on gut health in an enterotype-dependent manner.

Synergistic Anticancer Activity of Plumbagin and Xanthohumol Combination on Pancreatic Cancer Models.

Among diverse cancers, pancreatic cancer is one of the most aggressive types due to inadequate diagnostic options and treatments available. Therefore, there is a necessity to use combination chemotherapy options to overcome the chemoresistance of pancreatic cancer cells. Plumbagin and xanthohumol, natural compounds isolated from the Plumbaginaceae family and Humulus lupulus, respectively, have been used to treat various cancers. In this study, we investigated the anticancer effects of a combination of plumbagin and xanthohumol on pancreatic cancer models, as well as the underlying mechanism. We have screened in vitro numerous plant-derived extracts and compounds and tested in vivo the most effective combination, plumbagin and xanthohumol, using a transgenic model of pancreatic cancer KPC (KrasLSL.G12D/+; p53R172H/+; PdxCretg/+). A significant synergistic anticancer activity of plumbagin and xanthohumol combinations on different pancreatic cancer cell lines was found. The combination treatment of plumbagin and xanthohumol influences the levels of B-cell lymphoma (BCL2), which are known to be associated with apoptosis in both cell lysates and tissues. More importantly, the survival of a transgenic mouse model of pancreatic cancer KPC treated with a combination of plumbagin and xanthohumol was significantly increased, and the effect on BCL2 levels has been confirmed. These results provide a foundation for a potential new treatment for pancreatic cancer based on plumbagin and xanthohumol combinations.

Adverse Effects of Avobenzone on Boar Sperm Function: Disruption of Protein Kinase A Activity and Tyrosine Phosphorylation.

Avobenzone (AVO), an ultraviolet (UV) filter, is frequently used as an ingredient in personal cosmetics. This UV filter has been found to be easily exposed in swimming pools and beaches, and it has been detected in human urine and blood. Moreover, numerous studies have demonstrated that AVO exhibits endocrine-disrupting properties. Nevertheless, the effects of AVO on male fertility have not yet fully understood. Therefore, this study aimed to assess the effects of AVO on various sperm functions during capacitation. First, boar spermatozoa were treated with various AVO concentrations. After treatment, sperm motility and kinetic characteristics, capacitation status, intracellular adenosine triphosphate (ATP) levels, and sperm viability were evaluated. Moreover, Western blot analysis w.as conducted to evaluate protein kinase A (PKA) activity and tyrosine phosphorylation. As a result, AVO treatment significantly decreased total motility, progressive motility, and several kinetic characteristics at high concentrations (50 and 100 µM). Furthermore, the capacitation status dose-dependently decreased. Conversely, no significant differences in acrosome reaction, cell viability, and intracellular ATP levels were observed. However, the intracellular ATP level tended to decrease. In addition, AVO dose-dependently induced abnormal changes in PKA activity and tyrosine phosphorylation. Although AVO did not directly exert a toxic effect on cell viability, it ultimately negatively affected sperm functions through abnormal alterations in PKA activity and tyrosine phosphorylation. Thus, the potential implications on male fertility must be considered when contemplating the safe utilization of AVO.

Xanthohumol ameliorates drug-induced hepatic ferroptosis via activating Nrf2/xCT/GPX4 signaling pathway.

BACKGROUND: As a canonical iron-dependent form of regulated cell death (RCD), ferroptosis plays a crucial role in chemical-induced liver injuries. Previous studies have demonstrated that xanthohumol (Xh), a natural prenylflavonoid isolated from hops, exhibits anti-inflammatory, anti-antioxidative and hepatoprotective properties. However, the regulatory effects of Xh on hepatic ferroptosis and the underlying mechanism have not yet been fully elucidated. PURPOSE: To investigate the hepatoprotective effects of Xh against drug-induced liver injury (DILI) and the regulatory effects of Xh on hepatic ferroptosis, as well as to reveal the underlying molecular mechanisms. METHODS/STUDY DESIGN: The hepatoprotective benefits of Xh were investigated in APAP-induced liver injury (AILI) mice and HepaRG cells. Xh was administered intraperitoneally to assess its in vivo effects. Histological and biochemical studies were carried out to evaluate liver damage. A series of ferroptosis-related markers, including intracellular Fe2+ levels, ROS and GSH levels, the levels of MDA, LPO and 4-HNE, as well as the expression levels of ferroptosis-related proteins and modulators were quantified both in vivo and in vitro. The modified peptides of Keap1 by Xh were characterized utilizing nano LC-MS/MS. RESULTS: Xh remarkably suppresses hepatic ferroptosis and ameliorates AILI both in vitro and in vivo, via suppressing Fe2+ accumulation, ROS formation, MDA generation and GSH depletion, these observations could be considerably mitigated by the ferroptosis inhibitor ferrostatin-1 (Fer-1). Mechanistically, Xh could significantly activate the Nrf2/xCT/GPX4 signaling pathway to counteract AILI-induced hepatocyte ferroptosis. Further investigations showed that Xh could covalently modify three functional cysteine residues (cys151, 273, 288) of Keap1, which in turn, reduced the ubiquitination rates of Nrf2 and prolonged its degradation half-life. CONCLUSIONS: Xh evidently suppresses hepatic ferroptosis and ameliorates AILI via covalent modifying three key cysteines of Keap1 and activating Nrf2/xCT/GPX4 signaling pathway.

The involvement of calcium in the toxic effect of 4-methylethcathinone on SH-SY5Y cells.

Neurotoxicity induced by psychoactive substances is often accompanied by an imbalance of intracellular calcium ions. It is unclear whether calcium ions play a role in the toxicity induced by psychoactive substances. In the present study, we aimed to evaluate the occurrence of calcium dysregulation and its contribution to cytotoxicity in human neurotypic SH-SY5Y cells challenged with a recently developed psychoactive substance 4-methylethcathinone (4-MEC). An increase in the intracellular calcium was detected by inductively coupled plasma atomic emission spectrometry and Fluo-3 AM dye in SH-SY5Y cells after being treated with 4-MEC. The increase of intracellular Ca2+ level mediated G0/G1 cell cycle arrest and ROS/endoplasmic reticulum stress-autophagy signaling pathways to achieve the toxicity of 4-MEC. In particular, N-acetyl-L-cysteine, a classical antioxidant, was found to be a potential treatment for 4-MEC-induced toxicity. Taken together, our results demonstrate that an increase in intracellular calcium content is one of the mechanisms of 4-MEC-induced toxicity. This study provides a molecular basis for the toxicity mechanism and therapeutic intervention of psychoactive substances.

The Effect of Xanthohumol Derivatives on Apoptosis Induction in Canine Lymphoma and Leukemia Cell Lines.

Xanthohumol is a cancer chemopreventive agent that can interfere with the initiation, promotion, and progression phase of carcinogenesis via a variety of inhibitory mechanisms. Xanthohumol was reported as an effective agent against leukemia/lymphoma cells. In the present study, we investigated the effect of xanthohumol and its natural and semisynthetic derivatives against various canine leukemia/lymphoma cell lines. Xanthohumol, three hops minor prenylflavonoids (xanthohumol C, xanthohumol D, α,ß-dihydroxanthohumol) and four derivatives obtained by biotransformation (xanthohumol 4'-O-ß-D-(4‴-O-methyl)-glucopyranoside) as well as by chemical modification (1″,2″-dihydroxanthohumol K, 2,3-dehydroisoxanthohumol, (Z)-6,4'-dihydroxy-4-methoxy-7-prenylaurone) were tested for their antiproliferative and pro-apoptotic activities against the following canine leukemia/lymphoma cell lines: CLBL-1 (B-cell lymphoma), CLB70 (B-cell leukemia), and GL-1 (B-cell leukemia). The compounds were tested at a final concentration range of 0.1-30 µM for 48 h. All eight of the tested flavonoids exerted concentration-dependent cytotoxicity in the selected canine lymphoma/leukemia cell lines. Three compounds markedly decreased the viability of all cell lines with IC50 in the range of 0.5 to 8 µM. Double-staining of the treated cells with AnnexinV and propidium iodide revealed that the dying cells were mostly in the late apoptosis stage. ROS production and changes in mitochondrial potential were detected. Western blot analysis showed a decreased expression of Bcl-2. Canine lymphoma and leukemia cell lines are sensitive to xanthohumol derivatives, and the compounds acted through an apoptotic cell-death mechanism. These compounds, either used alone or in combination with other therapies, may be useful for the treatment of canine leukemia/lymphoma.

Xanthohumol-Enriched Beer Does Not Exert Antitumorigenic Effects on HeLa Cell Line In Vivo.

Xanthohumol is a hop-derived flavonoid that has been widely examined for its health-protecting and antitumorigenic properties, but not yet in a natural beer matrix. The aim of the study was to investigate the antitumorigenic potential of a xanthohumol-enriched beer in vivo. Four groups of 4 × 10 nude mice were formed. Following the injection of HeLa tumorigenic cell lines, the treatment groups were administered a xanthohumol supplementation for 100 days, either dissolved in beer or in an ethanolic solution with the same alcohol strength as beer. The control groups received un-supplemented material. The terminal tumor masses, liver weights, and plasma antioxidant capacities (FRAP and ABTS methods) were measured. For the statistical analysis, a two-way ANOVA test was performed (p < 0.05). There were no statistically significant differences in tumor size between the groups. Xanthohumol did not induce higher levels of plasma antioxidant capacity, neither in beer nor in the water-ethanol matrix. The terminal liver weights were significantly higher in the control group receiving the unsupplemented ethanol solution. Xanthohumol dissolved in beer or in the water-alcohol matrix did not have a protective effect on tumor growth, nor did it have a positive effect on plasma antioxidant capacity either. However, beer with added xanthohumol had a less harmful effect on the liver compared to the supplemented water-ethanol solution. Our results indicate the possible negative countereffect of ethanol; however, further investigations are needed.

Xanthohumol exerts anti-inflammatory effects in an in vitro model of mechanically stimulated cementoblasts.

Xanthohumol (XN) is a prenylated plant polyphenol that naturally occurs in hops and its products, e.g. beer. It has shown to have anti-inflammatory and angiogenesis inhibiting effects and it prevents the proliferation of cancer cells. These effects could be in particular interesting for processes within the periodontal ligament, as previous studies have shown that orthodontic tooth movement is associated with a sterile inflammatory reaction. Based on this, the study evaluates the anti-inflammatory effect of XN in cementoblasts in an in vitro model of the early phase of orthodontic tooth movement by compressive stimulation. XN shows a concentration-dependent influence on cell viability. Low concentrations between 0.2 and 0.8 µM increase viability, while high concentrations between 4 and 8 µM cause a significant decrease in viability. Compressive force induces an upregulation of pro-inflammatory gene (Il-6, Cox2, Vegfa) and protein (IL-6) expression. XN significantly reduces compression related IL-6 protein and gene expression. Furthermore, the expression of phosphorylated ERK and AKT under compression was upregulated while XN re-established the expression to a level similar to control. Accordingly, we demonstrated a selective anti-inflammatory effect of XN in cementoblasts. Our findings provide the base for further examination of XN in modulation of inflammation during orthodontic therapy and treatment of periodontitis.

Testing a very low-carbohydrate adaption of the Diabetes Prevention Program among adults with prediabetes: study protocol for the Lifestyle Education about prediabetes (LEAP) trial.

BACKGROUND: The Center for Disease Control and Prevention's National Diabetes Prevention Program (NDPP) aims to help individuals with prediabetes avoid progression to type 2 diabetes mellitus (T2DM) through weight loss. Specifically, the NDPP teaches individuals to follow a low-fat, calorie-restricted diet and to engage in regular physical activity to achieve ≥ 5% body weight loss. Most NDPP participants, however, do not achieve this weight loss goal, and glycemic control remains largely unchanged. One promising opportunity to augment the NDPP's weight loss and glycemic effectiveness may be to teach participants to follow a very low-carbohydrate diet (VLCD), which can directly reduce post-prandial glycemia and facilitate weight loss by reducing circulating insulin and enabling lipolysis. To date, there have been no high-quality, randomized controlled trials to test whether a VLCD can prevent progression to T2DM among individuals with prediabetes. The aim of this study is to test the effectiveness of a VLCD version the NDPP (VLC-NDPP) versus the standard NDPP. We hypothesize the VLC-NDPP will demonstrate greater improvements in weight loss and glycemic control. METHODS: We propose to conduct a 12-month, 1:1, randomized controlled trial that will assign 300 adults with overweight or obesity and prediabetes to either the NDPP or VLC-NDPP. The primary outcome will be glycemic control as measured by change in hemoglobin A1c (HbA1c) from baseline to 12 months. Secondary outcomes will include percent body weight change and changes in glycemic variability, inflammatory markers, lipids, and interim HbA1c. We will evaluate progression to T2DM and initiation of anti-hyperglycemic agents. We will conduct qualitative interviews among a purposive sample of participants to explore barriers to and facilitators of dietary adherence. The principal quantitative analysis will be intent-to-treat using hierarchical linear mixed effects models to assess differences over time. DISCUSSION: The NDPP is the dominant public health strategy for T2DM prevention. Changing the program's dietary advice to include a carbohydrate-restricted eating pattern as an alternative option may enhance the program's effectiveness. If the VLC-NDPP shows promise, this trial would be a precursor to a multi-site trial with incident T2DM as the primary outcome. TRIAL REGISTRATION: NCT05235425. Registered February 11, 2022.

Ligand and Structure-Based Virtual Screening in Combination, to Evaluate Small Organic Molecules as Inhibitors for the XIAP Anti-Apoptotic Protein: The Xanthohumol Hypothesis.

Herein, we propose two chalcone molecules, (E)-1-(4-methoxyphenyl)-3-(p-tolyl) prop-2-en-1-one and (E)-3-(4-hydroxyphenyl)-1-(2,4,6-trihydroxyphenyl) prop-2-en-1-one, based on the anticancer bioactive molecule Xanthohumol, which are suitable for further in vitro and in vivo studies. Their ability to create stable complexes with the antiapoptotic X-linked IAP (XIAP) protein makes them promising anticancer agents. The calculations were based on ligand-based and structure-based virtual screening combined with the pharmacophore build. Additionally, the structures passed Lipinski's rule for drug use, and their reactivity was confirmed using density functional theory studies. ADMET studies were also performed to reveal the pharmacokinetic potential of the compounds. The candidates were chosen from 10,639,400 compounds, and the docking protocols were evaluated using molecular dynamics simulations.

Significance of D- tryptophan in Contryphan-Ar1131 Conus peptide: Oxidative folding, trypsin binding, and photostabilization activity.

Distinct differences have been observed between L-tryptophan and D-tryptophan containing contryphan-Ar1131 in oxidative folding, trypsin binding, and photostabilization activity on avobenzone. [W5] contryphan-Ar1131 and [w5] contryphan-Ar1131 were chemically synthesized and characterized using RP-HPLC and mass spectrometry. Structural differences due to the change of configuration of tryptophan were evident from the optimized structures of contryphan-Ar1131 using density functional theory (DFT). The comparison of early events of oxidative folding has revealed the role of D-tryptophan in accelerating the formation of a disulfide bond. The optimized structures of the reduced form of peptides revealed the occurrence of aromatic-aromatic and aromatic-proline interactions in [w5] contryphan-Ar1131 which may be critical in aiding the oxidative folding reaction. The presence of the Lys6-Pro7 peptide bond indicates that contryphan-Ar1131 is resistant but may bind to trypsin allowing to assign the binding affinity of peptides to the protein surface. Competitive binding studies and molecular docking along with molecular dynamic (MD) simulations have revealed that [w5] contryphan-Ar1131 has more affinity for the active site of trypsin. Given tryptophan is a photostabilizer of FDA-approved chemical UV-A filter avobenzone, the report has compared the photostabilization activity of [W5]/ [w5] contryphan-Ar1131 on avobenzone under natural sunlight. [w5] contryphan-Ar1131 has better photostabilization activity than that of [W5] contryphan-Ar1131 and also individual D-tryptophan and L-tryptophan amino acids. These biochemical studies have highlighted the significance of D-tryptophan in contryphan-Ar1131 and its photostabilization activity on avobenzone may find applications in cosmetics.

Inhibition of Glutamine Cellular Uptake Contributes to the Cytotoxic Effect of Xanthohumol in Triple-Negative Breast Cancer Cells.

Breast cancer constitutes the most incident cancer and one of the most common causes of cancer-related death. "Glutamine addiction", an important metabolic feature of cancer cells, is dependent on supply of this amino acid from external sources. In this study, the effect of several polyphenols (catechin, epicatechin, EGCG, catechin:lysine, naringenin, hesperidin, malvidin, delphinidin, kaempferol, quercetin, rutin, myricetin, resveratrol, xanthohumol, and chrysin) upon glutamine (3H-GLN) uptake by human breast epithelial adenocarcinoma cell lines with distinct characteristics (MCF-7 and MDA-MB-231) was assessed.Several polyphenols interfere with 3H-GLN uptake by both cell lines. Xanthohumol markedly decreases total and Na+-dependent 3H-GLN uptake and showed a cytotoxic and anti-proliferative effect in MDA-MB-231 cells. Xanthohumol is as an uncompetitive inhibitor of Na+-dependent 3H-GLN uptake and inhibits GPNA (L-γ-glutamyl-p-nitroanilide)-sensitive, both ASCT2 (alanine, serine, cysteine transporter 2)-mediated and non-ASCT2-mediated 3H-GLN uptake. Xanthohumol does not interfere with the transcription rates of ASCT2. The cytotoxic effect of xanthohumol, but not its anti-proliferative effect, is GPNA-sensitive and related to ASCT2 inhibition. Combination of xanthohumol with the breast cancer chemotherapeutic agent doxorubicin results in an additive anti-proliferative, but not cytotoxic effect.We conclude that targeting glutamine uptake might constitute a potential interesting strategy for triple-negative breast cancer.

Xanthohumol: An underestimated, while potent and promising chemotherapeutic agent in cancer treatment.

Today, there is a growing interest nowadays in the use of herbal substances as cancer therapeutic agents. Over recent years, Xanthohumol (XTL) has been brought out as a prenylated chalcone that is found in hops (Humulus lupulus) and beer. XTL is being investigated for its potential properties, and it has been found to have various biological effects, including anti-microbial, anti-viral, and immunomodulatory. Other than these biological effects, it has also been found that XTL exerts anti-tumor effects. In the beginning, XTL, by modulating cell signaling pathways, including ERK, AKT, NF-κB, AMPK, Wnt/ß-catenin, and Notch signaling in cancer cells, inhibits tumor cell functions. Moreover, XTL, by inducing apoptotic pathways, either intrinsic or extrinsic, promotes cancer cell death and arrests the cell cycle. Furthermore, XTL inhibits metastasis, angiogenesis, cancer stemness, drug resistance, cell respiration, etc., which results in tumor aggressiveness inhibition. XTL has low solubility in water, and it has been hypothesized that some modifications, including biotinylation, can improve its pharmacogenetic characteristics. Additionally, XTL derivates such as dihydroXTL and tetrahydroXTL can be helpful for more anti-tumor activities. Using XTL with other anti-tumor agents is another approach to overcome tumor cell resistance. XTL or its derivatives, it is believed, might provide novel chemotherapeutic methods in future cancer therapy.

PI3K/AKT/Nrf2 signalling pathway is involved in the ameliorative effects of xanthohumol on amyloid ß-induced oxidative damage and bone loss.

OBJECTIVE: Xanthohumol (XAN), a natural isoflavone from Humulus lupulus L., possesses biological activities on relieving oxidative stress and osteoporosis (OP). This study aimed to evaluate the antioxidative and osteoprotective effect of XAN on Aß-injured osteoblasts, and explore its underlying mechanism. METHODS: Osteoblasts were pretreated with XAN followed by stimulation with Aß1-42. Cell proliferation, ALP activity, bone mineralization and bone formation index were measured. Apoptosis and reactive oxygen species (ROS) were analysed with flow cytometer. PI3K inhibitor LY294002 or siRNA-Nrf2 was added and transfected in osteoblasts, to further confirm whether the pathway participated in the regulation of XAN-induced cytoprotection. KEY FINDINGS: XAN markedly improved the proliferation, differentiation and mineralization of Aß-injured osteoblasts. Additionally, XAN reduced cell apoptosis rate and ROS level, and increased the expression of p-AKT, Nrf2, NQO1, HO-1 and SOD-2. More importantly, LY294002 or siNrf2 abolished the beneficial effect of XAN on osteoblasts activity and decreased the PI3K expression and inhibited its downstream proteins, indicating XAN activated PI3K/AKT/Nrf2 pathway in Aß-injured osteoblasts. CONCLUSION: It was the first time to reveal the antioxidative and osteoprotective effect of XAN through regulating PI3K/AKT/Nrf2 pathway in Aß-injured osteoblasts, which provides reference for the clinical application of XAN in the prevention and treatment of OP.