Spasmolytic Effect of Flopropione Does Not Involve Catechol-O- methyltransferase (COMT) Inhibition.

Flopropione (Flo) has been used for gallstone and urolithiasis as a spasmolytic agent almost exclusively in Japan. According to the package insert, its main mechanism is catechol-O-methyltransferase (COMT) inhibition and anti-serotonergic effect. This is obviously contrary to pharmacological common sense, but it is described that way in pharmacology textbooks and occurs in questions in the National Examination for Pharmacists in Japan. As this is a serious problem in education, we re-examined the action of Flo. The guinea pig ureter was hardly contracted by serotonin, but noradrenaline (NA) elicited repetitive twitch contraction, which was inhibited by Flo. The sphincter of Oddi (SO) exhibited a spontaneous repetitive twitch contraction, which was inhibited by NA and Flo. The inhibitory effect of NA was reversed by α- and ß-blockers, whereas that of Flo was not. Entacapone, a representative COMT inhibitor, did not affect the movement of the ureter and the SO. Nifedipine suppressed carbachol-induced contraction of the taenia coli, spontaneous movement of the SO, and NA-induced contraction of the ureter to almost the same extent, whereas Flo did not inhibit the taenia coli, but inhibited the contraction of the SO and the ureter. The inhibitory pattern of Flo resembled that of the ryanodine receptor agonist 4-chloro-m-cresol and the inositol 1,4,5-trisphosphate (IP3) receptor antagonist 2-aminoethoxydiphenyl borate. It is concluded that COMT inhibition or serotonin inhibition is not involved in the spasmolytic action of Flo. Flo might act on ryanodine receptors and/or IP3 receptors, which are responsible for periodic Ca release from Ca stores, to disrupt coordinated Ca dynamics.

Eperisone Hydrochloride, a Muscle Relaxant, Is a Potent P2X7 Receptor Antagonist.

Eperisone Hydrochloride was launched in Japan in 1983 and has been used to improve muscle tone and treat spastic paralysis (Originator: Eisai Co., Ltd.). However, its biochemical mechanism of action is unknown. SB Drug Discovery was used to evaluate purinergic P2X (P2X) receptor antagonism using fluorescence. In this study, we discovered that its target protein is the P2X7 receptor. Also, P2X receptor subtype selectivity was high. This finding demonstrates the (Eperisone-P2X7-pain linkage), the validity of P2X7 as a drug target, and the possibility of drug repositioning of Eperisone Hydrochloride.

Gut Microbiota and Inflammation Modulation in a Rat Model for Ulcerative Colitis after the Intraperitoneal Administration of Apigenin, Luteolin, and Xanthohumol.

Ulcerative colitis (UC) is a chronic inflammatory disorder affecting the colon, with symptomatology influenced by factors including environmental, genomic, microbial, and immunological interactions. Gut microbiota dysbiosis, characterized by bacterial population alterations, contributes to intestinal homeostasis disruption and aberrant immune system activation, thereby exacerbating the inflammatory state. This study assesses the therapeutic efficacy of intraperitoneal (IP) injected flavonoids (apigenin, luteolin, and xanthohumol) in the reduction of inflammatory parameters and the modulation of the gut microbiota in a murine model of ulcerative colitis. Flavonoids interact with gut microbiota by modulating their composition and serving as substrates for the fermentation into other anti-inflammatory bioactive compounds. Our results demonstrate the effectiveness of luteolin and xanthohumol treatment in enhancing the relative abundance of anti-inflammatory microorganisms, thereby attenuating pro-inflammatory species. Moreover, all three flavonoids exhibit efficacy in the reduction of pro-inflammatory cytokine levels, with luteolin strongly demonstrating utility in alleviating associated physical UC symptoms. This suggests that this molecule is a potential alternative or co-therapy to conventional pharmacological interventions, potentially mitigating their adverse effects. A limited impact on microbiota is observed with apigenin, and this is attributed to its solubility constraints via the chosen administration route, resulting in its accumulation in the mesentery.

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.

Sulfonate Derivatives Containing a Kakuol Moiety as Potential Fungicidal Candidates: Design, Synthesis and Antifungal Activity Evaluation.

As a part of our continuing exploration to discover new potential promising fungicide candidates, eighteen sulfonate derivatives (3a-3r) containing a kakuol moiety were designed and synthesized. Synthetic sulfonate derivatives were tested comprehensively for antifungal activities against four plant pathogenic fungi (Botrytis (B.) cinerea, Valsa (V.) mali, Fusarium (F.) graminearum, Sclerotinia (S.) sclerotiorum), and their structure activity relationships were summarized. Especially, derivatives 3i and 3j exhibited remarkable activity against V. mali, with the inhibition rates of 99.8 and 100%, which were slightly superior to that of carbendazim (98.9%), a reference fungicide. Moreover, derivatives 3a, 3k and 3q possess the broader antifungal spectrum against three tested plant pathogenic fungi with inhibition rates over 60%. Structure-activity relationship (SAR) analysis indicated that the introduction of 2-F or 3-F into the benzene ring would give rise to a remarkable increase of the antifungal activity against V. mali.

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.

Metabolic profile of N-ethylhexedrone, N-ethylpentedrone, and 4-chloromethcathinone in urine samples by UHPLC-QTOF-HRMS.

Forensic laboratories are constantly required to identify new drugs and their metabolites. N-ethylhexedrone (NEH, HEXEN), N-Ethylpentedrone (NEP), and 4-Chloromethcathinone (4-CMC, clephedrone) are synthetic substances structurally related to natural cathinone, alkaloid present in the leaves of the Catha edulis (Khat) plant. These synthetic cathinones (SC) are members of the heterogenous family of new psychoactive substances (NPS) that raised major concerns in scientific and forensic communities over the past years due to their widespread consumption. In this context, we investigated their metabolic profile using of UHPLC-QTOF-HRMS to elucidate the distribution of the parent drug and its metabolites in urine samples over time. Initially, both male and female volunteers were divided into three groups and eight subjects of each group were administered intranasally or orally with one SC (20-40 mg of NEH or NEP intranasal, 100-150 mg of 4-CMC oral). Urine samples were collected at 0-2 and 2-4 or 2-5 h. Urine (50 µL) was diluted 1:2 with acetonitrile/methanol (95:5) and injected into the UHPLC-QTOF-HRMS. Phase-I and phase-II metabolites were identified on the basis of fragmentation patterns and exact masses. Several phase-I and glucuronide-phase-II metabolites were identified in urine samples. Keto group reduction, hydroxylation and dealkylation were the common metabolic pathways identified for all cathinones and the presence of NEH-glucuronide, NEP-glucuronide and 4-CMC-glucuronide was also relevant. Significant is the slower metabolite formation for 4-CMC, which was detected at high concentrations in its original form even 5 h after administration, due to its long half-life and low intrinsic clearance compared to the other SCs. UHPLC-QTOF-HRMS demonstrated a considerable capability to semi-quantify the three synthetic cathinones and identify the target metabolites with high reliability. The introduction of new target compounds improves the efficiency of toxicological screening analysis on real samples and extends the window of detection of the SCs in biological matrices.

Are TaNAC Transcription Factors Involved in Promoting Wheat Yield by cis-Regulation of TaCKX Gene Family?

NAC transcription factors (TFs) are one of the largest TF families in plants, and TaNACs have been known to participate in the regulation of the transcription of many yield-regulating genes in bread wheat. The TaCKX gene family members (GFMs) have already been shown to regulate yield-related traits, including grain mass and number, leaf senescence, and root growth. The genes encode cytokinin (CK) degrading enzymes (CKXs) and are specifically expressed in different parts of developing wheat plants. The aim of the study was to identify and characterize TaNACs involved in the cis-regulation of TaCKX GFMs. After analysis of the initial transcription factor data in 1.5 Kb cis-regulatory sequences of a total of 35 homologues of TaCKX GFMs, we selected five of them, namely TaCKX1-3A, TaCKX22.1-3B, TaCKX5-3D, TaCKX9-1B, and TaCKX10, and identified five TaNAC genes: TaNACJ-1, TaNAC13a, TaNAC94, TaNACBr-1, and TaNAC6D, which are potentially involved in the cis-regulation of selected TaCKX genes, respectively. Protein feature analysis revealed that all of the selected TaNACs have a conserved NAC domain and showed a stable tertiary structure model. The expression profile of the selected TaNACs was studied in 5 day-old seedling roots, 5-6 cm inflorescences, 0, 4, 7, and 14 days-after-pollination (DAP) spikes, and the accompanying flag leaves. The expression pattern showed that all of the selected TaNACs were preferentially expressed in seedling roots, 7 and 14 DAP spikes, and flag leaves compared to 5-6 cm inflorescence and 0 and 4 DAP spikes and flag leaves in Kontesa and Ostka spring wheat cultivars (cvs.). In conclusion, the results of this study highlight the potential role of the selected TaNACs in the regulation of grain productivity, leaf senescence, root growth, and response to various stresses.

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.

Impurities in over-the-counter pseudoephedrine leading to methcathinone detection in urine.

Methcathinone, a psychoactive substance with stimulant properties, has raised concerns in recent years due to its presence in urine screenings, even among individuals with no history of drug abuse. To prevent misjudgment, this work aims to explore the source of methcathinone in urine. A total of 58 urine samples tested positive for methcathinone in the National Taiwan University Hospital cohort, with 27 linked to illicit drug use and 31 from individuals with no drug use history. Co-occurrence analysis revealed a strong association between methcathinone and over-the-counter cold medications containing pseudoephedrine or ephedrine. In an in vivo experiment, participants who consumed pseudoephedrine-containing drugs showed the presence of methcathinone in their urine, suggesting a connection between these substances. Additionally, tests on pharmaceutical products containing pseudoephedrine detected small amounts of methcathinone as impurities. The findings suggest that the presence of methcathinone in nonillicit drug users may be attributed to impurities in over-the-counter pseudoephedrine-containing medications. This raises concerns about potential misinterpretations of drug screening results and underscores the need for more comprehensive criteria for assessing drug use. This study contributes to our understanding of the origin of methcathinone in urine, which has implications for legal justice and drug screening practices.

Disturbance of consciousness caused by dyclonine hydrochloride mucilage: a case report.

BACKGROUND: Dyclonine hydrochloride mucilage is a topical anaesthetic formulated for mucosal surfaces. It is employed frequently for topical anaesthesia of the pharynx prior to endoscopic examinations such as electronic gastroscopy, and few adverse reactions have been reported. This article describes a patient who experienced a transient but severe disturbance of consciousness following oral dyclonine hydrochloride mucilage administration. CASE PRESENTATION: A 75-year-old female presenting with gastrointestinal bleeding was examined by electronic gastroscopy. Six minutes after oral dyclonine hydrochloride mucilage administration, the patient entered a comatose-like state accompanied by loss of limb muscle tone and profuse perspiration. This response was not accompanied by changes in cardiac rhythm, blood pressure, or respiration rate, suggesting an effect on higher brain centres. After ten minutes, the patient's symptoms were alleviated. CONCLUSION: We suggest that sites of dyclonine hydrochloride mucilage use be equipped with appropriate rescue devices for these rare events.

Xanthohumol, a prenylated flavonoid from hops (Humulus lupulus L.) exerts multidirectional pro-healing properties towards damaged zebrafish hair cells by regulating the innate immune response.

Xanthohumol (XN) is a prominent prenylated flavonoid present in the hop plant (Humulus lupulus L.). Despite undoubted pro-healing properties of hop plant, there is still a need for clinical investigations confirming these effects as well as the underlying molecular mechanisms. The present study was designed to (1) establish the role of XN in non-invasive inflammation induced by chemical damage to zebrafish hair cells, (2) clarify if it influences cell injury severity, neutrophil migration, macrophage activation, cell regeneration, and (3) find out whether it modulates the gene expression profile of chosen immune and stress response markers. All experiments were performed on 3 dpf zebrafish larvae. After fertilization the embryos were transferred to appropriate XN solutions (0.1 µM, 0.3 µM and 0.5 µM). The 40 min 10 µM CuSO4 exposure evoked severe damage to posterior lateral line hair cells triggering a robust acute inflammatory response. Four readouts were selected as the indicators of XN role in the process of inflammation: 1) hair cell death, 2) neutrophil migration towards damaged hair cells, 3) macrophage activation and recruitment to damaged hair cells, 4) hair cell regeneration. The assessments involved in vivo confocal microscopy imaging and qPCR based molecular analysis. It was demonstrated that XN (1) influences death pathway of damaged hair cells by redirecting their severe necrotic phenotype into apoptotic one, (2) impacts the immune response via regulating neutrophil migration, macrophage recruitment and activation (3) modulates gene expression of immune system markers and (4) accelerates hair cell regeneration.

Muscle Strength Decline Caused by Eperisone Hydrochloride: A Case Report.

A 65-year-old female with thoracic spinal stenosis and incomplete paraplegia underwent T11-T12 posterior thoracic interbody fusion. During postoperative rehabilitation, she experienced thigh pain, involuntary lower limb convulsions, and muscle fatigue. Despite being prescribed eperisone hydrochloride for relief, her muscle strength decreased after 14 doses. This adverse effect, not listed in the latest Chinese medication instructions, subsided 4 days after discontinuation. This case suggests eperisone hydrochloride potentially caused reversible muscle strength decline, highlighting its potential unsuitability for incomplete paraplegia patients due to possible further muscle strength reduction. We propose updating the medication instructions to alert clinicians to this risk.

Mechanistic Skin Modeling of Plasma Concentrations of Sunscreen Active Ingredients Following Facial Application.

Sunscreen products constitute two distinct categories. Recreational sunscreens protect against high-intensity, episodic sun exposure, often applied over the entire body. In contrast, facial sunscreen products are designed for sub-erythemal, low-intensity daily sun exposure. Such different exposures necessitate distinctive product safety assessments. Building on earlier methods for predicting dermal disposition, a mechanistic model was developed to simulate plasma concentrations of seven organic sunscreen active ingredients: avobenzone, ensulizole, homosalate, octinoxate, octisalate, octocrylene, and oxybenzone, following facial application. In vitro permeation testing (IVPT) was performed with two different vehicles using a subset of the UV filters. These IVPT results, in addition to previously published IVPT data and published in vivo Maximal Usage Trial (MUsT) data for the UV filters, were used to train the mechanistic dermal model via a Bayesian Markov chain Monte Carlo (MCMC) method. An external validation of the trained model with real-world in vivo datasets demonstrated that the model's predicted UV filter plasma concentrations align well with experimental measurements and capture the observed inter-individual variability. Predictions of steady-state UV filter plasma concentrations under facial application scenarios at 5% concentration and at the maximal allowable concentrations were then generated by the trained model. Oxybenzone had the greatest predicted plasma concentration following facial application. Homosalate and octisalate predictions had high uncertainty associated with the absence of data. Several application scenarios pertaining to avobenzone, ensulizole, octocrylene and octinoxate were identified in which median plasma concentration levels were at 0.5 ng/ml or below when applied in the recreational or facial product. Model limitations include uncertainty in vehicle/water partitioning, formulation metamorphosis, and UV filter systemic clearance, all of which can be refined with additional data. For UV filters, limiting exposure to facial application reduces human safety concerns based on FDA established thresholds.

Compounds derived from Humulus lupulus inhibit SARS-CoV-2 papain-like protease and virus replication.

BACKGROUND: Selected natural compounds exhibit very good antiviral properties. Especially, the medicinal plant Humulus lupulus (hop) contains several secondary plant metabolites some of which have previously shown antiviral activities. Among them, the prenylated chalcone xanthohumol (XN) demonstrated to be a potent inhibitor of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) main protease (Mpro). HYPOTHESIS/PURPOSE: Following the finding that xanthohumol (XN) is a potent inhibitor of SARS-CoV-2 Mpro, the effect of XN and its major derivatives isoxanthohumol (IXN), 6-prenylnaringenin (6-PN), and 8-prenylnaringenin (8-PN) from hops on SARS-CoV-2 papain-like protease (PLpro) were investigated. STUDY DESIGN: The modulatory effect of the hop compounds on PLpro were studied first in silico and then in vitro. In addition, the actual effect of hop compounds on the replication of SARS-CoV-2 in host cells was investigated. METHODS: In silico docking analysis was used to predict the binding affinity of hop compounds to the active site of PLpro. A recombinant PLpro was cloned, purified, characterized, and analyzed by small-angle X-ray scattering (SAXS), deISGylation assays, and kinetic analyses. Antiviral activity of hop compounds was assessed using the fluorescently labeled wildtype SARS-CoV-2 (icSARS-CoV-2-mNG) in Caco-2 host cells. RESULTS: Our in silico docking suggests that the purified hop compounds bind to the active site of SARS-CoV-2 PLpro blocking the access of its natural substrates. The hop-derived compounds inhibit SARS-CoV-2 PLpro with half maximal inhibitory concentration (IC50) values in the range of 59-162 µM. Furthermore, we demonstrate that XN and 6-PN, in particular, impede viral replication with IC50 values of 3.3 µM and 7.3 µM, respectively. CONCLUSION: In addition to the already known inhibition of Mpro by XN, our results show, for the first time, that hop-derived compounds target also SARS-CoV-2 PLpro which is a promising therapeutic target as it contributes to both viral replication and modulation of the immune system. These findings support the possibility to develop new hop-derived antiviral drugs targeting human coronaviruses.

Selective inhibition of overactive warmth-sensitive Ca2+-permeable TRPV3 channels by antispasmodic agent flopropione for alleviation of skin inflammation.

The temperature-sensitive Ca2+-permeable TRPV3 ion channel is robustly expressed in the skin keratinocytes, and its gain-of-function mutations are involved in the pathology of skin lesions. Here, we report the identification of an antispasmodic agent flopropione that alleviates skin inflammation by selective inhibition of TRPV3. In whole-cell patch clamp recordings, flopropione selectively inhibits macroscopic TRPV3 currents in a concentration-dependent manner with an IC50 value of 17.8 ± 3.5 µM. At the single-channel level, flopropione inhibits TRPV3 channel open probability without alteration of its unitary conductance. In an in vivo mouse model of skin inflammation induced by the skin sensitizer DNFB, flopropione also alleviates dorsal skin lesions and ear skin swelling. Further molecular docking combined with site-directed mutagenesis reveals that two residues E501 and I505 in the channel S2-helix are critical for flopropione-mediated inhibition of TRPV3. Taken together, our findings demonstrate that the spasmolytic drug flopropione as a selective inhibitor of TRPV3 channel not only provides a valuable tool molecule for understanding of TRPV3 channel pharmacology but also holds repurposing potential for therapy of skin disorders, such as dermatitis and pruritus.