Design, synthesis, and evaluation of formylpiperazine analogs of Ferrostatin-1 as novel improved ferroptosis inhibitors.

In this study, a series of new formylpiperazine-derived ferroptosis inhibitors were designed and synthesized based on the structure of a known ferroptosis inhibitor, ferrostatin-1 (Fer-1). The anti-ferroptosis activity of these synthetic compounds in human umbilical vein endothelial cells (HUVECs) induced by Erastin was evaluated. It was found that some of the new compounds, especially compound 26, showed potent anti-ferroptosis activity, as evidenced by its ability to restore cell viability, reduce iron accumulation, scavenge reactive oxygen species, maintain mitochondrial membrane potential, increase GSH levels, decrease LPO and MDA content, and upregulate GPX4 expression. Moreover, compound 26 exhibited superior microsomal stability than Fer-1. The present results suggest that compound 26 is a promising lead compound for the development of new ferroptosis inhibitors for the treatment of vascular diseases.

Design, synthesis, and evaluation of novel ferrostatin derivatives for the prevention of HG-induced VEC ferroptosis.

Ferroptosis is a nonapoptotic, iron-catalyzed form of regulated cell death. It has been shown that high glucose (HG) could induce ferroptosis in vascular endothelial cells (VECs), consequently contributing to the development of various diseases. This study synthesized and evaluated a series of novel ferrostatin-1 (Fer-1) derivatives fused with a benzohydrazide moiety to prevent HG-induced VEC ferroptosis. Several promising compounds showed similar or improved inhibitory effects compared to positive control Fer-1. The most effective candidate 12 exhibited better protection against erastin-induced ferroptosis and high glucose-induced ferroptosis in VECs. Mechanistic studies revealed that compound 12 prevented mitochondrial damage, reduced intracellular ROS accumulation, upregulated the expression of GPX4, and decreased the amounts of ferrous ion, LPO and MDA in VECs. However, compound 12 still exhibited undesirable microsomal stability like Fer-1, suggesting the need for further optimization. Overall, the present findings highlight ferroptosis inhibitor 12 as a potential lead compound for treating ferroptosis-associated vascular diseases.

Synthesis and biological evaluation of 1-phenyl-tetrahydro-ß-carboline-based first dual PRMT5/EGFR inhibitors as potential anticancer agents.

Protein arginine methyltransferase 5 (PRMT5) and epidermal growth factor receptor (EGFR) are both involved in the regulation of various cancer-related processes, and their dysregulation or overexpression has been observed in many types of tumors. In this study, we designed and synthesized a series of 1-phenyl-tetrahydro-ß-carboline (THßC) derivatives as the first class of dual PRMT5/EGFR inhibitors. Among the synthesized compounds, 10p showed the most potent dual PRMT5/EGFR inhibitory activity, with IC50 values of 15.47 ± 1.31 and 19.31 ± 2.14 µM, respectively. Compound 10p also exhibited promising antiproliferative activity against A549, MCF7, HeLa, and MDA-MB-231 cell lines, with IC50 values below 10 µM. Molecular docking studies suggested that 10p could bind to PRMT5 and EGFR through hydrophobic, π-π, and cation-π interactions. Furthermore, 10p displayed favorable pharmacokinetic properties and oral bioavailability (F = 30.6%) in rats, and administrated orally 10p could significantly inhibit the growth of MCF7 orthotopic xenograft tumors. These results indicate that compound 10p is a promising hit compound for the development of novel and effective dual PRMT5/EGFR inhibitors as potential anticancer agents.

An Updated Overview of Synthetic α-glucosidase Inhibitors: Chemistry and Bioactivities.

Diabetes mellitus (DM) is a critical global health issue, affecting nearly half a billion people worldwide, with an increasing incidence rate and mortality. Type 2 diabetes is caused by the body's inability to effectively use insulin, and approximately 95% of patients have type 2 diabetes. α-glucosidase has emerged as an important therapeutic target for the treatment of type 2 diabetes. In the past years, three α-glucosidase inhibitors have been approved for clinical use, namely acarbose, voglibose, and miglitol. However, the undesirable effects associated with these carbohydrate mimic-based α-glucosidase inhibitors have limited their clinical applications. Consequently, researchers have shifted their focus towards the development of non-carbohydrate mimic α-glucosidase inhibitors that can safely and effectively manage postprandial hyperglycemia in type 2 diabetes. Herein, this article provides an overview of the synthetic α-glucosidase inhibitors, particularly those based on heterocycles, which have been reported from 2018 to 2022. This article aims to provide useful information for medicinal chemists in further developing clinically available anti-type 2 diabetes drugs.

Discovery of marine phidianidine-based Nrf2 activators and their potential against oxLDL- and HG-induced injury in HUVECs.

One effective strategy for treating atherosclerosis is to inhibit the injury of vascular endothelial cells (VECs) induced by oxidized low-density lipoprotein (oxLDL) and high glucose (HG). This study synthesized and evaluated a series of novel Nrf2 activators derived from the marine natural product phidianidine for their ability to protect human umbilical VECs against oxLDL- and HG-induced injury. The results of in vitro bioassays demonstrated that compound D-36 was the most promising Nrf2 activator, effectively inhibiting the apoptosis of HUVECs induced by oxLDL and HG. Furthermore, Nrf2 knockdown experiments confirmed that compound D-36 protected against oxLDL- and HG-induced apoptosis in HUVECs by activating the Nrf2 pathway. These findings provide important insights into a new chemotype of marine-derived Nrf2 activators that could potentially be optimized to develop effective anti-atherosclerosis agents.

New cycloalkyl[b]thiophenylnicotinamide-based α-glucosidase inhibitors as promising anti-diabetic agents: Synthesis, in silico study, in vitro and in vivo evaluations.

In the present study, a series of cycloalkyl[b]thiophenylnicotinamide derivatives against α-glucosidase were synthesized, and evaluated for their in vitro and in vivo anti-diabetic potential. Most of the synthetic analogues exhibited superior α-glucosidase inhibitory effects than the standard drug acarbose (IC50 = 258.5 µM), in which compound 11b with cyclohexyl[b]thiophene core demonstrated the highest activity with an IC50 value of 9.9 µM and showed higher selectivity towards α-glucosidase over α-amylase by 7.4-fold. Fluorescence quenching experiment confirmed the direct binding of 11b with α-glucosidase, kinetics study revealed that 11b was a mixed-type inhibitor, and its binding mode was analyzed using molecular docking. Moreover, analogs compounds 6a-9b, 11b, 12b did not show in vitro cytotoxicity against LO2 and HepG2 cells. Finally, compound 11b exhibited in vivo hypoglycemic activity by reducing the blood glucose levels in sucrose-loaded rats.

Design, synthesis and biological evaluation of novel (E)-2-benzylidene-N-(3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl)hydrazine-1-carboxamide derivatives as α-glucosidase inhibitors.

In this present study, a series of novel (E)-2-benzylidene-N-(3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl)hydrazine-1-carboxamide derivatives against α-glucosidase were designed and synthesized, and their biological activities were evaluated in vitro and in vivo. Most of the designed analogues exhibited better inhibitory activity than the marketed acarbose, especially the most potent compound 7 with an IC50 value of 9.26 ± 1.84 µM. The direct binding of 7 and 8 with α-glucosidase was confirmed by fluorescence quenching experiments, and the kinetic and molecular docking studies revealed that 7 and 8 inhibited α-glucosidase in a non-competitive manner. Cytotoxicity bioassay indicated compounds 7 and 8 were non-toxic towards LO2 and HepG2 at 100 µM. Furthermore, both compounds were demonstrated to have in vivo hypoglycemic activity by reducing the blood glucose levels in sucrose-treated rats.

Discovery of new 2-phenyl-1H-benzo[d]imidazole core-based potent α-glucosidase inhibitors: Synthesis, kinetic study, molecular docking, and in vivo anti-hyperglycemic evaluation.

In the present study, a series of 2-phenyl-1H-benzo[d]imidazole-based α-glucosidase inhibitors were synthesized and evaluated for their in vitro and in vivo anti-diabetic potential. Screening of an in-house library revealed a moderated α-glucosidase inhibitor, 6a with 3-(1H-benzo[d]imidazol-2-yl)aniline core, and then the structural optimization was performed to obtain more efficient derivatives. Most of these derivatives showed increased activity than 6a, and the most promising inhibitors were found to be compounds 15o and 22d with IC50 values of 2.09 ± 0.04 and 0.71 ± 0.02 µM, respectively. Fluorescence quenching experiment confirmed the direct binding of compounds 15o and 22d with α-glucosidase. Kinetic study revealed that both compounds were non-competitive inhibitors, that was consistent with the result of molecular docking studies where they located at the allosteric site of the enzyme. Cell viability evaluation demonstrated the non-cytotoxicity of 15o and 22d against LO2 cells. Furthermore, the in vivo pharmacodynamic study revealed that compound 15o showed significant hypoglycemic activity and improved oral sucrose tolerance, comparable to the positive control acarbose.

Discovery of New α-Glucosidase Inhibitors: Structure-Based Virtual Screening and Biological Evaluation.

α-Glycosidase inhibitors could inhibit the digestion of carbohydrates into glucose and promote glucose conversion, which have been used for the treatment of type 2 diabetes. In the present study, 52 candidates of α-glycosidase inhibitors were selected from commercial Specs compound library based on molecular docking-based virtual screening. Four different scaffold compounds (7, 22, 37, and 44) were identified as α-glycosidase inhibitors with IC50 values ranging from 9.99 to 35.19 µM. All these four compounds exerted better inhibitory activities than the positive control (1-deoxynojirimycin, IC50 = 52.02 µM). The fluorescence quenching study and kinetic analysis revealed that all these compounds directly bind to α-glycosidase and belonged to the noncompetitive α-glycosidase inhibitors. Then, the binding modes of these four compounds were carefully investigated. Significantly, these four compounds showed nontoxicity (IC50 > 100 µM) toward the human normal hepatocyte cell line (LO2), which indicated the potential of developing into novel candidates for type 2 diabetes treatment.

A highly sensitive endoplasmic reticulum-targeting fluorescent probe for the imaging of endogenous H2S in live cells.

Hydrogen sulfide (H2S) as an important signaling biomolecule participates in a series of complex physiological and pathological processes. In situ and rapid detection of H2S levels in endoplasmic reticulum (ER) is of great importance for the in-depth study of its virtual functional roles. However, the ER-targeting fluorescent probe for the detection of H2S in live cells is still quite rare. Herein, a new ER-targeting fluorescent probe (FER-H2S) for detecting H2S in live cells was characterized in the present study. This probe FER-H2S was built from the hybridization of three parts, including fluorescein-based skeleton, p-toluenesulfonamide as ER-specific group, and 2,4-nitrobenzene sulfonate as a response site for H2S. The response mechanism of the probe FER-H2S to H2S is on the basis of the ring-opening and ring-closing processes in fluorescein moiety. Moreover, the probe FER-H2S was successfully used for the imaging of exogenous and endogenous H2S in ER of live cells.

A novel lipid droplets-targeting ratiometric fluorescence probe for hypochlorous acid in living cells.

Lipid droplets were found to be involved in many organism activities. Here, a lipid droplets-targeted near-infrared fluorescence probe (named XHZ) for ratiometric detection of endogenous hypochlorous acid/hypochlorite (HClO/ClO-) in living cells was developed, which was constructed by a coumarin moiety and a malononitrile derivative. XHZ could detect HClO/ClO- with high selectivity and sensitivity in a ratiometric manner based on FRET (Förster Resonance Energy Transfer) mechanism. The two well-resolved emission (470/672 nm) bands could ensure accurate detection of HClO/ClO- in vitro as well as in vivo. XHZ was successfully used for ratiometric fluorescence imaging of exogenous and endogenous HClO/ClO- in RAW264.7 cells. A good linear relationship between the fluorescence intensity ratios of the two emissions and HClO/ClO- concentrations from 0 to 40 µM was obtained. Importantly, XHZ could localize mainly in lipid droplets of RAW264.7 cells. To the best of our knowledge, XHZ is the first lipid droplets-targeted ratiometric fluorescence probe for HClO/ClO-.

Modeling and analysis of visual digital impact model for a Chinese human thorax.

OBJECTIVE: To establish a three-dimensional finite element model of the human chest for engineering research on individual protection. METHOD: Computed tomography (CT) scanning data were used for three-dimensional reconstruction with the medical image reconstruction software Mimics. The finite element method (FEM) preprocessing software ANSYS ICEM CFD was used for cell mesh generation, and the relevant material behavior parameters of all of the model's parts were specified. The finite element model was constructed with the FEM software, and the model availability was verified based on previous cadaver experimental data. RESULTS: A finite element model approximating the anatomical structure of the human chest was established, and the model's simulation results conformed to the results of the cadaver experiment overall. CONCLUSION: Segment data of the human body and specialized software can be utilized for FEM model reconstruction to satisfy the need for numerical analysis of shocks to the human chest in engineering research on body mechanics.

Is endoscopic treatment beneficial in patients with clinically suspicious of common bile duct stones but no obvious filling defects during the ERCP examination?

BACKGROUND: Sometimes, no definite filling defect could be found by cholangiogram (ERC) during the endoscopic retrograde cholangio-pancreatiographic (ERCP) exam; even prior images had evidence of common bile duct stones (CBDS). We aimed in estimating the positive rate of extraction of CBDS who had treated by endoscopic sphincterotomy/endoscopic papillary balloon dilation (EST/EPBD) with negative ERC finding. METHODS: One hundred forty-one patients with clinically suspicious of CBDS but negative ERC, who had received EST/EPBD treatments was enrolled. Potential factors for predicting CBDS, as well as the treatment-related complications were analyzed. RESULTS: Nearly half of the patients with negative ERC, had a positive stone extraction. Only patients with high probability of CBDS were significantly associated with positive stone extraction. Moreover, patients with intermediate probability of CBDS had higher rates of overall complications, including post-ERCP pancreatitis. In addition, no significant difference of post-ERCP pancreatitis was found between EST and EPBD groups in any one group of patients with the same probability of CBDS. CONCLUSIONS: Regarding patients with negative ERC, therapeutic ERCP is beneficial and safe for patients present with high probability of CBDS. Moreover, under the same probability of CBDS, there was no significance difference in post-ERCP pancreatitis between EST and EPBD.

The efficacy of endoscopic papillary balloon dilation for patients with acute biliary pancreatitis.

Background. No study investigated the efficacy and safety of endoscopic papillary balloon dilation (EPBD) for the treatment of acute biliary pancreatitis (ABP). Method. We retrospectively reviewed the effects of EPBD on patients with ABP from February 2003 to December 2012. The general data, findings of image studies, details of the procedure, and outcomes after EPBD were analyzed. Result. Total 183 patients (male/female: 110/73) were enrolled. The mean age was 65.9 years. Among them, 155 patients had mild pancreatitis. The meantime from admission to EPBD was 3.3 days. Cholangiogram revealed filling defects inside the common bile duct (CBD) in 149 patients. The mean dilating balloon size was 10.5 mm and mean duration of the dilating procedure was 4.3 minutes. Overall, 124 patients had gross stones retrieved from CBD. Four (2.2%) adverse events and 2 (1.1%) intraprocedure bleeding incidents but no procedure-related mortality were noted. Bilirubin and amylase levels significantly decreased after EPBD. On average, patients resumed oral intake within 1.4 days. The clinical parameters and outcomes were similar in patients with different severity of pancreatitis. Conclusion. EPBD can be effective and safe for the treatment of ABP, even in patients presenting with severe disease.

Comparison of hemostatic efficacy of argon plasma coagulation with and without distilled water injection in treating high-risk bleeding ulcers.

BACKGROUND: Argon plasma coagulation (APC) is useful to treat upper gastrointestinal bleeding, but its hemostatic efficacy has received little attention. Aims. This investigation attempted to determine whether additional endoscopic injection before APC could improve hemostatic efficacy in treating high-risk bleeding ulcers. METHODS: From January 2007 to April 2011, adult patients with high-risk bleeding ulcers were included. This investigation compared APC plus distilled water injection (combined group) to APC alone for treating high-risk bleeding ulcers. Outcomes were assessed based on initial hemostasis, surgery, blood transfusion, hospital stay, rebleeding, and mortality at 30 days posttreatment. RESULTS: Totally 120 selected patients were analyzed. Initial hemostasis was accomplished in 59 patients treated with combined therapy and 57 patients treated with APC alone. No significant differences were noted between these groups in recurred bleeding, emergency surgery, 30-day mortality, hospital stay, or transfusion requirements. Comparing the combined end point of mortality plus the failure of initial hemostasis, rebleeding, and the need for surgery revealed an advantage for the combined group (P = 0.040). CONCLUSIONS: Endoscopic therapy with APC plus distilled water injection was no more effective than APC alone in treating high-risk bleeding ulcers, whereas combined therapy was potentially superior for patients with poor overall outcomes.

Linear echoendoscope-guided ERCP for the diagnosis of occult common bile duct stones.

BACKGROUND: Less than 67% of patients with intermediate risk for common bile duct (CBD) stones require therapeutic intervention. It is important to have an accurate, safe, and reliable method for the definitive diagnosis of CBD stones before initiating therapeutic endoscopic retrograde cholangiopancreatography (ERCP). Few publications detail the diagnostic efficacy of linear echoendoscopy (EUS) for CBD stones. METHODS: 30 patients with biliary colic, pancreatitis, unexplained derangement of liver function tests, and/or dilated CBD without an identifiable cause were enrolled in the study. When a CBD stone was disclosed by linear EUS, ERCP with stone extraction was performed. Patients who failed ERCP were referred for surgical intervention. If no stone was found by EUS, ERCP would not be performed and patients were followed-up for possible biliary symptoms for up to three months. RESULTS: The major reason for enrollment was acute pancreatitis. The mean predicted risk for CBD stones was 47% (28-61). Of the 12 patients who were positive for CBD stones by EUS, nine had successful ERCP, one failed ERCP (later treated successfully by surgical intervention) and two were false-positive cases. No procedure-related adverse events were noted. For those 18 patients without evidence of CBD stones by EUS, no false-negative case was noted during the three-month follow-up period. Linear EUS had sensitivity, specificity, positive and negative predicted values for the detection of CBD stones of 1, 0.9, 0.8 and 1, respectively. CONCLUSION: Linear EUS is safe and efficacious for the diagnosis of occult CBD stones in patients with intermediate risk for the disease.

Upper gastrointestinal lesions in patients receiving clopidogrel anti-platelet therapy.

BACKGROUND/PURPOSE: Clopidogrel is associated with a high incidence of upper gastrointestinal bleeding in high-risk patients. However, the characteristic upper gastrointestinal lesions in symptomatic clopidogrel users remain unclear. The aims of this study were to investigate the characteristics of endoscopic findings in clopidogrel users undergoing endoscopy for upper gastrointestinal symptoms and to compare the clinical characteristics and upper gastrointestinal lesions between symptomatic clopidogrel and aspirin users. METHODS: This observational study included 215 consecutive patients receiving clopidogrel (n=106) or low-dose aspirin (n=109) therapy who underwent endoscopy for dyspeptic symptoms. The upper gastrointestinal lesions were carefully assessed, and a complete medical history was obtained by a standard questionnaire. RESULTS: The frequencies of hemorrhagic spots, erosions and peptic ulcers in the symptomatic clopidogrel users were 25%, 39% and 39%, respectively. Among the peptic ulcer patients on clopidogrel therapy, the distributions of ulcers were 78%, 5% and 17% in the stomach, duodenum and both, respectively. Compared with the aspirin group, the clopidogrel group was older and had higher frequencies of past ulcer history and past gastrointestinal bleeding history in their clinical characteristics. By contrast, the clopidogrel users had a lower prevalence of active Helicobacter pylori infection than aspirin users (17% vs. 35%, respectively, p=0.007). Regarding to the endoscopic findings, the clopidogrel users had higher frequencies of hemorrhagic spots (25% vs. 10%) and peptic ulcer (39% vs. 24%) than aspirin users (p=0.004 and 0.027, respectively). CONCLUSION: Most peptic ulcers in clopidogrel users are located in the stomach. The frequencies of hemorrhagic spots and peptic ulcers in symptomatic clopidogrel users are higher than those in symptomatic aspirin users.

Sequential therapy achieves a higher eradication rate than standard triple therapy in Taiwan.

BACKGROUND AND AIMS: Most clinical trials concerning sequential therapy have been conducted in Italy. The efficacy of sequential therapy for Helicobacter pylori (H. pylori) eradication in Asia remains unclear. The aim of this study was to compare the efficacy of sequential therapy with standard triple therapy in Taiwan. METHODS: From January 2005 to December 2009, 233 H. pylori-infected patients receiving either a 10-day sequential therapy (40 mg pantoprazole and 1 g amoxicillin, twice daily, for the initial 5 days, followed by 40 mg pantoprazole, 500 mg clarithromycin, and 500 mg metronidazole, twice daily, for the subsequent 5 days, n = 118) or a 7-day standard triple therapy (40 mg pantoprazole, 500 mg clarithromycin, and 1 g amoxicillin twice daily for 7 days, n = 115) were included in the retrospective study. All the patients underwent a follow-up endoscopy with a rapid urease test and histological examination or a urea breath test at 8 weeks after the end of anti-H. pylori therapy to assess H. pylori status. RESULT: Intention-to-treat analysis demonstrated a significantly higher eradication rate for the sequential group than for the triple group (93% vs 80%, respectively, P = 0.003). Per-protocol analysis also showed similar results (93% vs 80%, P = 0.005). Both groups had similar frequencies of adverse events (29% vs 22%) and drug compliance (98% vs 97%). CONCLUSION: Sequential therapy achieves a higher eradication rate than standard triple therapy in Taiwan. The novel treatment can be used as a first-line therapy for H. pylori infection for Taiwanese.

Ginsenosides stimulated the proliferation of mouse spermatogonia involving activation of protein kinase C.

The effect of ginsenosides on proliferation of type A spermatogonia was investigated in 7-day-old mice. Spermatogonia were characterized by c-kit expression and cell proliferation was assessed by immunocytochemical demonstration of proliferating cell nuclear antigen (PCNA). After 72-h culture, Sertoli cells formed a confluent monolayer to which numerous spermatogonial colonies attached. Spermatogonia were positive for c-kit staining and showed high proliferating activity by PCNA expression. Ginsenosides (1.0 approximately10 microg/ml) significantly stimulated proliferation of spermatogonia. Activation of protein kinase C (PKC) elicited proliferation of spermatogonia at 10(-8) to 10(-7) mol/L and the PKC inhibitor H(7) inhibited this effect. Likewise, ginsenosides-stimulated spermatogonial proliferation was suppressed by combined treatment of H(7). These results indicate that the proliferating effect of ginsenosides on mouse type A spermatogonia might be mediated by a mechanism involving the PKC signal transduction pathway.

Attenuating effect of daidzein on polychlorinated biphenyls-induced oxidative toxicity in mouse testicular cells.

The attenuating effect of daidzein (DAI) on oxidative toxicity induced by Aroclor 1254 (A1254) was investigated in mouse testicular cells. Cells were exposed to A1254 alone or with DAI. The oxidative damage was estimated by measuring malondialdehyde (MDA) formation, superoxide dismutase (SOD) activity and glutathione (GSH) content. Results show that A1254 induced a decrease of germ cell number, an elevation in thiobarbituric acid reactive substances (TBARS) but a decrease in SOD activity and GSH content. However, simultaneous supplementation with DAI decreased TBARS level and increased SOD activity and GSH content. Consequently, dietary DAI may restore the intracellular antioxidant system to attenuate the oxidative toxicity of A1254 in testicular cells.