Rapid screening of lipase inhibitors in licorice extract by using porcine pancreatic lipase immobilized on Fe3O4 magnetic nanoparticles

Exploration potential sepsis-ferroptosis mechanisms through the use of CETSA technology and network pharmacology

As an important self-protection response mechanism of the body, inflammation can not only remove the necrotic or even malignant cells in the body, but also take a series of targeted measures to eliminate the pathogen of foreign invasion and block the foreign substances that may affect the life and health of the body. Flavonoids have known anti-inflammatory, anti-oxidation, anti-cancer and other effects, including glycyrrhizin molecules is one of the representatives. Licochalcone D has known anti-inflammatory and antioxidant properties and is effective in the treatment of a variety of inflammatory diseases. However, the underlying mechanism for the treatment of sepsis remains unclear. In this study, the therapeutic potential of Licochalcone D for sepsis was studied by analyzing network pharmacology and molecular dynamics simulation methods. Sepsis-related genes were collected from the database to construct PPI network maps and drug-targeting network profiles. The potential mechanism of Licochalcone D in sepsis was predicted by gene ontology, KEGG and molecular dynamics simulation. Sixty drug-disease genes were subsequently validated. Go analysis showed that monomeric small molecule Licochalcone D could regulate the process of intracellular enzyme system. The KEGG pathway analysis showed that the signal pathway of the main effect was related to the calcium pathway. The results of intersections with iron death-related target genes showed that ALOX5, ALOX15B and other nine targets all had the effect of possibly improving sepsis, while GSE 54,514, GSE 95,233 and GSE 69,528 were used to analyze the survival rate and ROC curve. Five genes were screened, including ALOX5, ALOX15B, NFE2L2 and NR4A1, HIF1A. The results of molecular docking showed that ALOX5 and Licochalcone D had strong binding activity. Finally, the results of molecular dynamics simulation showed that there was good binding power between drug and target. In the present study, we utilized molecular dynamics simulation techniques to assess the binding affinity between the small-molecule ligand and the protein receptor. The simulation outcomes demonstrate that the binding interface between the ligand and receptor remains stable, with a calculated binding free energy (ΔG) of -32.47 kJ/mol. This signifies a high-affinity interaction between the ligand and receptor, suggesting the long-term stability of the small molecule under physiological conditions. These findings provide critical insights for drug development efforts. This study elucidates the therapeutic potential of Licochalcone D, a traditional Chinese medicine monomer, in improving sepsis through the regulation of ferroptosis, thereby providing a new direction and option for subsequent clinical drug development in the treatment of sepsis.

Rapid Screening of Lipase Inhibitors From Chrysanthemum Based on Ionic Liquid/Chitosan Bifunctionalized Magnetic Multi-Walled Carbon Nanotubes Immobilized Lipase

In this study, a novel ionic liquid/chitosan bifunctionalized magnetic multi-walled carbon nanotubes composite material (m-MWCNTs@CS@IL) was utilized for the first time to immobilize lipase. The immobilized lipase exhibited exceptional stability and reusability, as evidenced by its characteristic properties. A ligand fishing approach utilizing the immobilized lipase was developed to enable rapid screening of lipase inhibitors from Chrysanthemum. Three ligands were successfully screened from Chrysanthemum and then identified as cynaroside, quercitrin, and linarin by ultra-high performance liquid chromatography-tandem mass spectrometry. The IC50 values of these three ligands were 76.77 ± 0.36, 83.01 ± 0.46, and 43.61 ± 0.77 µM, respectively. Furthermore, molecular docking analysis further confirmed the binding of three ligands to specific amino acid residues within the active site of lipase. This work presents a fast and efficient approach for screening lipase inhibitors from intricate natural sources, demonstrating promising prospects in discovering anti-obesity compounds.

In situ identification of gastroprotective components from Dendrobium huoshanense using magnetic nanoparticles combined with biomaterials assisted EFISI-MS

The identification of natural active compounds is typically a cumbersome and time-intensive process due to the necessity for elaborate sample pretreatment, leading to inefficiencies. Although recent advancements have introduced methods for targeted screening of these active compounds, they still demand intricate sample handling, and in severe cases, critical active compounds may be lost or degraded beyond detection. This study capitalizes on the novel discovery that Fe3O4 magnetic nanoparticles (MNPs) can be stably immobilized onto a magnetized steel probe of the electrostatic field induced spray ionization mass spectrometry (EFISI-MS) platform. By employing a method that targets the isolation of active compounds using MNPs paired with biomaterials (such as enzymes and cell membranes), we fixed complexes of cell membranes bound to Fe3O4 MNPs onto the magnetized probe through magnetic adsorption. This modified probe enables direct sampling from fresh plants, followed by EFISI-MS analysis. Employing this method, we successfully identified three gastroprotective compounds (schaftoside, isoschaftoside and 4-allyl-2,6-dimethoxyphenyl glucoside) directly from fresh Dendrobium huoshanense in situ, eliminating the need for preliminary sample treatment. The structures of these compounds were confirmed through total synthesis and comparative analysis with standards. Further biological experiments demonstrated that these compounds not only enhanced the survival rate of MNNG induced GES-1 cells in vitro in a dose-dependent manner but also significantly ameliorated gastric mucosal injury in a mouse model. Furthermore, the conventional approach using Fe3O4 MNPs combined with cell membranes to extract components from D. huoshanense failed to detect active compound 4-allyl-2,6-dimethoxyphenyl glucoside. This demonstrates that our newly developed methodology not only facilitates the direct in situ identification of plant derived active compounds but also significantly improves the detection rate of these bioactive substances.

Carboxy-Functionalized Covalent Organic Framework as a Carrier for Lipase Immobilization and Its Application in Inhibitors Screening

Covalent organic frameworks (COFs) with large specific surface areas, high porosity, good stability, and designable structure are promising carriers for immobilized enzymes. It is important to explore lipase inhibitors from natural foods as lipase inhibitors are closely related to the treatment of obesity. In this work, a carboxyl functionalized covalent organic framework (TpBD-3COOH) was prepared by solvothermal method for covalent immobilization of porcine pancreatic lipase (PPL) and obtained the enzyme-decorated COF (PPL@COF). The immobilized lipase showed wider pH and temperature tolerance with the same optimal pH and temperature of 7.5 and 50 ℃ compared to free lipase. After 6 successive reuses, the PPL@COF maintained 53.0% of its original activity. Immobilized lipase also displayed enhanced storage stability (55.4% after 14 days at 4 ℃). When p-nitrophenyl acetate was applied as the substrate, the calculated Michaelis constant was 3.57 mM and the half maximal inhibitory concentration of orlistat was 3.20 μM. Finally, the PPL@COF was used for enzyme inhibitors screening from natural foods combined with UV spectrophotometry, and Hawthorn was screened for excellent lipase inhibitory activity.

A magnetic beads-based ligand fishing method Coupled with UHPLC-QTOF MS for screening and identification of α-glucosidase inhibitors from Houttuynia cordata Thunb

In this study, a method for the screening and identification of α-glucosidase inhibitors from natural products was developed. The α-glucosidase was immobilized on carboxyl terminated magnetic beads to form a ligand fishing system to screen the potential inhibitors. A total of 9 compounds were fishing out from the crude Houttuynia cordata Thunb. extract. Meanwhile, ultra-high performance liquid chromatography quadrupole time-of-flight mass spectrometry (UHPLC-QTOF MS) was used for the identification of the chemical structures, including 3 chlorogenic acid isomers, 2 flavone C-glycosides and 4 flavone O-glycosides. The combination of enzyme immobilization magnetic beads and UHPLC-QTOF MS could be used for the screening of bioactive multi-components from herbs with appropriate targets. Taking the advantage of the specificity of enzyme binding and the convenience of magnetic separation, the method has great potential for rapid screening of α-glucosidase inhibitors from complicated natural product extracts.

Natural Chalcones for the Management of Obesity Disease

In the last decade, the incidence of obesity has increased dramatically worldwide, reaching a dangerous pandemic spread. This condition has serious public health implications as it significantly increases the risk of chronic diseases such as type 2 diabetes, fatty liver, hypertension, heart attack, and stroke. The treatment of obesity is therefore the greatest health challenge of our time. Conventional therapeutic treatment of obesity is based on the use of various synthetic molecules belonging to the class of appetite suppressants, lipase inhibitors, hormones, metabolic regulators, and inhibitors of intestinal peptide receptors. The long-term use of these molecules is generally limited by various side effects and tolerance. For this reason, the search for natural alternatives to treat obesity is a current research goal. This review therefore examined the anti-obesity potential of natural chalcones based on available evidence from in vitro and animal studies. In particular, the results of the main in vitro studies describing the principal molecular therapeutic targets and the mechanism of action of the different chalcones investigated were described. In addition, the results of the most relevant animal studies were reported. Undoubtedly, future clinical studies are urgently needed to confirm and validate the potential of natural chalcones in the clinical prophylaxis of obesity.

A rationally engineered specific near-infrared fluorogenic substrate of human pancreatic lipase for functional imaging and inhibitor screening

Obesity, now widespread all over the world, is frequently associated with several chronic diseases. Human pancreatic lipase (hPL) is a crucial digestive enzyme responsible for the digestion of dietary lipids in humans, and the inhibition of hPL is effective in reducing triglyceride intake and thus preventing and treating obesity. In this work, a practical sequential screening strategy was developed to construct a highly selective near-infrared fluorogenic substrate 7-STCFC for hPL. Under physiological conditions, 7-STCFC can be rapidly hydrolyzed by hPL to form 7-HTCFC, which triggers 254-fold NIR signal enhancement at 670 nm. 7-STCFC was successfully applied for the sensing and imaging of endogenous PL in living systems (including living cells, tissues and organs) with low cytotoxicity and high imaging resolution. Moreover, a high-throughput screening platform was established using 7-STCFC, and the inhibitory effects of 94 kinds of herbs toward hPL were evaluated. Among them, Pu-erh tea stood out with outstanding hPL inhibitory effects, and the inhibitory ingredients and involved inhibitory mechanism were further revealed, which strongly facilitates the discovery of novel anti-obesity agents targeting hPL. Collectively, these findings suggested that our strategy was practical to develop an isoform-specific fluorogenic substrate for a target enzyme, and 7-STCFC was a powerful tool for monitoring PL activity in complex biological systems with value for exploring physiological functions and rapid screening of inhibitors.

Efficient screening of pancreatic lipase inhibitors from cod meat hydrolysate through ligand fishing strategy

Obesity has become an increasingly serious public health problem. Pancreatic lipase (PL) is identified as a ideal target for the prevention and treatment of obesity. Orlistat, the only approved PL inhibitor (PLI), is a powerful weight loss drug but has many side effects. Therefore, there is an urgent need to discover powerful PLIs with high safety. Protein hydrolysate has been demonstrated to be a treasure trove of PLIs, but recognizing responsible functional peptides from them is like looking for a needle in a haystack. In this work, we synthesized and optimized a PL ligand fishing model (PLLFM) using magnetic nanoparticles (MNPs), then PLLFM was used to quickly fish out potential PLIs from the Cod meat hydrolysate (CMH). Finally, two new PLIs, GSPPPSG and KLEGDLK were identified with IC₅₀ of 0.60 and 1.08 mg/mL, respectively. The Lineweaver-Burk diagram showed that GSPPPSG is a non-competitively dominant mixed-type PLI, whereas KLEGDLK is a competitive inhibitory-type PLI. Moreover, molecular docking suggested that both peptides can stably bind to the key amino acid residues of the PL active site, mainly through hydrogen bonding, hydrophobic, and electrostatic interactions. In general, we not only established a method to rapidly fish out potential PLIs from protein hydrolysate, but also provided safe and efficient lead compounds for the development of novel diet foods or drugs.

Rapid Screening of Lipase Inhibitors from Ophiopogonis Radix Using High-Performance Thin Layer Chromatography by Two Step Gradient Elution Combined with Bioautographic Method

In this study, a high-performance thin layer chromatography (HPTLC) method by two step gradient elution with two mobile phases was developed for the simultaneous analysis of seven constituents in Ophiopogonis Radix. The chromatography was performed on silica gel 60 F₂₅₄ plate with dichloromethane-methanol-ethyl acetate-water (70:25:12:3, v/v/v/v) and dichloromethane-methanol (300:1, v/v) as the mobile phase for two step gradient elution. Then, the HPTLC profiles were observed after derivatization with 10% sulfuric acid in ethanol solution. The obtained HPTLC images were further analyzed by chemometric approaches and the samples could be clustered based on regions and/or growth years, which were two important factors affecting the constituents in Ophiopogonis Radix. Furthermore, five compounds including ophiopogonin D, ophiopojaponin C, ophiopogonin D’, ophiopogonin C’ and methylophiopogonanone B were screened as potential lipase inhibitors from Ophiopogonis Radix by the HPTLC-bioautographic method. The binding modes and interactions between the five compounds and lipase were further explored by molecular docking analysis. The developed HPTLC method could be used for quality control of Ophiopogonis Radix and screening of the potential lipase inhibitors.

Preparation and characterization of active oxidized starch films containing licorice residue extracts and its potential against methicillin-resistant S. aureus

The antibacterial and antioxidant packaging films were fabricated by incorporating licorice residue extracts (LREs) into oxidized starch (OS) films. The bioactive fraction (BF) was firstly obtained from LREs by using bioassay-guided isolation method. The BF showed potent anti-Gram⁽⁺⁾ bacteria effects, especially against methicillin-resistant S. aureus (MRSA) with MIC of 32.5 μg/mL. The present results also indicated that the addition of BF could significantly decrease the moisture content, water vapor permeability, light transmittance of OS films. Notably, the antibacterial and antioxidant activities of OS films significantly enhanced with the concentration of BF increasing. Moreover, the films with the highest concentration of BF showed the lowest tensile strength (4.23 MPa) and the highest elongation at break (63.89%). Meanwhile, the bioactive films could release bioactive compounds such as licochalcone A and licochalcone B into the alcoholic and fatty food simulants. Taken together, the active OS films containing LREs have the potential for application in food packaging films, due to its potential against MRSA and antioxidant activity as well as good physicochemical properties.