-
Biomedicine & Pharmacotherapy =... Aug 2023Male infertility is a worldwide problem but few treatments, especially irradiation-induced testicular injury. The aim of this research was to investigate novel drugs for...
Novel treatment and insight for irradiation-induced injuries: Dibucaine ameliorates irradiation-induced testicular injury by inhibiting fatty acid oxidation in primary Leydig cells.
BACKGROUND
Male infertility is a worldwide problem but few treatments, especially irradiation-induced testicular injury. The aim of this research was to investigate novel drugs for the treatment of irradiation-induced testicular injury.
METHODS
We administered dibucaine (0.8 mg/kg) intraperitoneally to male mice (6 mice per group) after five consecutive daily 0.5 Gy whole-body irradiation, and evaluated its ameliorating efficacy by testicular HE staining and morphological measurements. Drug affinity responsive target stability assay (Darts) were used to find target protein and pathway; mouse primary Leydig cells were isolated and to explore the mechanism (Flow cytometry, Western blot, and Seahorse palmitate oxidative stress assays); finally rescue experiments were completed by combining dibucaine with fatty acid oxidative pathway inhibitors and activators.
RESULTS
The testicular HE staining and morphological measurements in dibucaine treatment group was significantly better than that in irradiation group (P < 0.05); sperm motility and mRNA levels of spermatogenic cell markers were also higher than those in the latter (P < 0.05). Darts and Western blot results showed that dibucaine targets CPT1A and downregulate fatty acid oxidation. Flow cytometry, Western blot, and Palmitate oxidative stress assays of primary Leydig cells demonstrated that dibucaine inhibits fatty acid oxidation in Leydig cells. Dibucaine combined with etomoxir/baicalin confirmed that its inhibition of fatty acid oxidation was beneficial in ameliorating irradiation-induced testicular injury.
CONCLUSIONS
In conclusion, our data suggest that dibucaine ameliorates irradiation-induced testicular injury in mice by inhibiting fatty acid oxidation in Leydig cells. This will provide novel ideas for the treatment of irradiation-induced testicular injury.
Topics: Humans; Male; Mice; Animals; Leydig Cells; Dibucaine; Sperm Motility; Testis; Testicular Diseases; Fatty Acids; Palmitates
PubMed: 37224756
DOI: 10.1016/j.biopha.2023.114903 -
MBio Apr 2023The intracellular membrane domain (IMD) is a laterally discrete region of the mycobacterial plasma membrane, enriched in the subpolar region of the rod-shaped cell....
The intracellular membrane domain (IMD) is a laterally discrete region of the mycobacterial plasma membrane, enriched in the subpolar region of the rod-shaped cell. Here, we report genome-wide transposon sequencing to discover the controllers of membrane compartmentalization in Mycobacterium smegmatis. The putative gene showed the most significant effect on recovery from membrane compartment disruption by dibucaine. Enzymatic analysis of Cfa and lipidomic analysis of a deletion mutant (Δ) demonstrated that Cfa is an essential methyltransferase for the synthesis of major membrane phospholipids containing a C monomethyl-branched stearic acid, also known as tuberculostearic acid (TBSA). TBSA has been intensively studied due to its abundant and genus-specific production in mycobacteria, but its biosynthetic enzymes had remained elusive. Cfa catalyzed the -adenosyl-l-methionine-dependent methyltransferase reaction using oleic acid-containing lipid as a substrate, and Δ accumulated C oleic acid, suggesting that Cfa commits oleic acid to TBSA biosynthesis, likely contributing directly to lateral membrane partitioning. Consistent with this model, Δ displayed delayed restoration of subpolar IMD and delayed outgrowth after bacteriostatic dibucaine treatment. These results reveal the physiological significance of TBSA in controlling lateral membrane partitioning in mycobacteria. As its common name implies, tuberculostearic acid is an abundant and genus-specific branched-chain fatty acid in mycobacterial membranes. This fatty acid, 10-methyl octadecanoic acid, has been an intense focus of research, particularly as a diagnostic marker for tuberculosis. It was discovered in 1934, and yet the enzymes that mediate the biosynthesis of this fatty acid and the functions of this unusual fatty acid in cells have remained elusive. Through a genome-wide transposon sequencing screen, enzyme assay, and global lipidomic analysis, we show that Cfa is the long-sought enzyme that is specifically involved in the first step of generating tuberculostearic acid. By characterizing a deletion mutant, we further demonstrate that tuberculostearic acid actively regulates lateral membrane heterogeneity in mycobacteria. These findings indicate the role of branched fatty acids in controlling the functions of the plasma membrane, a critical barrier for the pathogen to survive in its human host.
Topics: Humans; Dibucaine; Mycobacterium; Stearic Acids; Fatty Acids; Oleic Acid; Methyltransferases
PubMed: 36976029
DOI: 10.1128/mbio.03396-22 -
Pain Practice : the Official Journal of... Feb 2024Over-the-counter (OTC) local anesthetics have historically been used to alleviate pain in several common conditions including toothache and sore throat. With a rise in... (Review)
Review
Over-the-counter (OTC) local anesthetics have historically been used to alleviate pain in several common conditions including toothache and sore throat. With a rise in chronic conditions and an aging population, there has been an increase in associated chronic pain-related disorders. Individuals with chronic pain often seek OTC treatments for quick and accessible pain relief. There are several common OTC local anesthetics, including benzocaine, lidocaine, and dibucaine, which are readily available to patients in several formulations. In order to appropriately advise patients on the use of local anesthetics, it is important to understand their key characteristics, including the mechanism of action, clinical properties, pharmacokinetics, clinical applications, and adverse reactions, which may occur.
Topics: Humans; Aged; Anesthetics, Local; Chronic Pain; Lidocaine; Benzocaine; Dibucaine; Anesthetics
PubMed: 37750534
DOI: 10.1111/papr.13298 -
Frontiers in Cellular and Infection... 2024Picornaviruses, which are positive-stranded, non-enveloped RNA viruses, are known to infect people and animals with a broad spectrum of diseases. Among the nonstructural... (Review)
Review
Picornaviruses, which are positive-stranded, non-enveloped RNA viruses, are known to infect people and animals with a broad spectrum of diseases. Among the nonstructural proteins in picornaviruses, 2C proteins are highly conserved and exhibit multiple structural domains, including amphipathic α-helices, an ATPase structural domain, and a zinc finger structural domain. This review offers a comprehensive overview of the functional structures of picornaviruses' 2C protein. We summarize the mechanisms by which the 2C protein enhances viral replication. 2C protein interacts with various host factors to form the replication complex, ultimately promoting viral replication. We review the mechanisms through which picornaviruses' 2C proteins interact with the NF-κB, RIG-I, MDA5, NOD2, and IFN pathways, contributing to the evasion of the antiviral innate immune response. Additionally, we provide an overview of broad-spectrum antiviral drugs for treating various enterovirus infections, such as guanidine hydrochloride, fluoxetine, and dibucaine derivatives. These drugs may exert their inhibitory effects on viral infections by targeting interactions with 2C proteins. The review underscores the need for further research to elucidate the precise mechanisms of action of 2C proteins and to identify additional host factors for potential therapeutic intervention. Overall, this review contributes to a deeper understanding of picornaviruses and offers insights into the antiviral strategies against these significant viral pathogens.
Topics: Humans; Animals; Picornaviridae; NF-kappa B; RNA; Virus Replication; Antiviral Agents; Structure-Activity Relationship
PubMed: 38465233
DOI: 10.3389/fcimb.2024.1347615 -
Pharmaceutics Nov 2018Dibucaine (DBC) is among the more potent long-acting local anesthetics (LA), and it is also one of the most toxic. Over the last decades, solid lipid nanoparticles (SLN)...
Dibucaine (DBC) is among the more potent long-acting local anesthetics (LA), and it is also one of the most toxic. Over the last decades, solid lipid nanoparticles (SLN) have been developed as promising carriers for drug delivery. In this study, SLN formulations were prepared with the aim of prolonging DBC release and reducing its toxicity. To this end, SLN composed of two different lipid matrices and prepared by two different hot-emulsion techniques (high-pressure procedure and sonication) were compared. The colloidal stability of the SLN formulations was tracked in terms of particle size (nm), polydispersity index (PDI), and zeta potential (mV) for 240 days at 4 °C; the DBC encapsulation efficiency was determined by the ultrafiltration/centrifugation method. The formulations were characterized by differential scanning calorimetry (DSC), electron paramagnetic resonance (EPR), and release kinetic experiments. Finally, the in vitro cytotoxicity against 3T3 fibroblast and HaCaT cells was determined, and the in vivo analgesic action was assessed using the test in rats. Both of the homogenization procedures were found suitable to produce particles in the 200 nm range, with good shelf stability (240 days) and high DBC encapsulation efficiency (~72⁻89%). DSC results disclosed structural information on the nanoparticles, such as the lower crystallinity of the lipid core vs. the bulk lipid. EPR measurements provided evidence of DBC partitioning in both SLNs. In vitro (cytotoxicity) and in vivo () experiments revealed that the encapsulation of DBC into nanoparticles reduces its intrinsic cytotoxicity and prolongs the anesthetic effect, respectively. These results show that the SLNs produced are safe and have great potential to extend the applications of dibucaine by enhancing its bioavailability.
PubMed: 30441802
DOI: 10.3390/pharmaceutics10040231 -
Biochimica Et Biophysica Acta.... Jun 2019Mitochondrial membranes are pointed out as the site of cardiotoxic action of local anaesthetics. Its three main phospholipids components are phosphatidylcholine,...
Mitochondrial membranes are pointed out as the site of cardiotoxic action of local anaesthetics. Its three main phospholipids components are phosphatidylcholine, phosphatidylethanolamine and cardiolipin. Cardiolipins, in eukaryotes, are only found in mitochondria and are essential for the maintenance of its integrity and dynamics. Fluorescence and nuclear magnetic resonance spectroscopy were used to study the interactions of a local anaesthetics, Dibucaine (DBC), with different mitochondrial membrane models constituted by combinations of its three main lipid components in which cardiolipin was a natural extract (CL). Both CL presence/absence and its percentage in the model membranes were evaluated. Fluorescence spectroscopy showed that DBC lowered the transition temperature of all membrane models understudy. DBC partition showed to be dependent of CL presence and phosphatidylethanolamine:CL ratio. Furthermore, the maximum emission wavelength (λ) exhibited a notorious decreased with increasing phospholipid to DBC ratio, in all the membrane models containing CL. Nevertheless, it remained approximately the same in the membrane without CL. This indicates a differential membrane localization of the anaesthetics, dependent on the membrane models used. NMR results showed that DBC interaction and location in the membrane models is mainly influenced by CL presence, and DBC can significant alter lipid systems properties e.g. percentage and type of lipid phase present. Taken all together it was shown that DBC interaction and location are largely dependent on the membrane model system. Furthermore, DBC is able to produce significant changes in the lipidic systems which might help to explain its high toxicity.
Topics: Anesthetics, Local; Binding Sites; Cardiolipins; Dibucaine; Mitochondrial Membranes; Models, Biological; Phosphatidylethanolamines; Temperature
PubMed: 30840858
DOI: 10.1016/j.bbamem.2019.02.011 -
Frontiers in Microbiology 2022Human enterovirus infections are mostly asymptomatic and occasionally could be severe and life-threatening. The conserved non-structural 2C from enteroviruses protein is...
Human enterovirus infections are mostly asymptomatic and occasionally could be severe and life-threatening. The conserved non-structural 2C from enteroviruses protein is a promising target in antiviral therapies against human enteroviruses. Understanding of 2C-drug interactions is crucial for developing the potential antiviral agents. While functions of enterovirus 2C proteins have been widely studied, three-dimensional structure information of 2C is limited. In this study, the structures of 2C proteins from 20 enteroviruses were simulated and reconstructed using programs. Subsequent docking studies of the known 22 antiviral inhibitors for 2C proteins were performed to uncover the inhibitor-binding characteristics of 2C. Among the potential inhibitors, the compound hydantoin exhibited the highest broad-spectrum antiviral activities with binding to 2C protein. The anti-enteroviral activity of GuaHCL, compound 19b, R523062, compound 12a, compound 12b, quinoline analogs 12a, compound 19d, N-benzyladenosine, dibucaine derivatives 6i, TBZE-029, fluoxetine analogs 2b, dibucaine, 2-(α-hydroxybenzyl)-benzimidazole (HBB), metrifudil, pirlindole, MRL-1237, quinoline analogs 10a, zuclopenthixol, fluoxetine, fluoxetine HCl, and quinoline analogs 12c showed a trend of gradual decrease. In addition, the free energy with 22 compounds binding to EV 2C ranged from -0.35 to -88.18 kcal/mol. Our studies will provide important information for the development of pan-enterovirus antiviral agents based on 2C.
PubMed: 35572704
DOI: 10.3389/fmicb.2022.856574 -
Journal of Clinical Biochemistry and... Jul 2023This study aimed to illustrate the dose-response relationships of the direct scavenging activity of amide-based local anesthetics against multiple free radicals . We...
This study aimed to illustrate the dose-response relationships of the direct scavenging activity of amide-based local anesthetics against multiple free radicals . We have demonstrated that amide-type local anesthetics selectively and directly scavenge some free radicals. Three kinds of free radicals were eliminated by all the four local anesthetics examined. Mepivacaine, lidocaine, bupivacaine, and dibucaine scavenged hydroxyl radicals in dose-dependent manners. Ascorbyl free radicals were also scavenged in dose-dependent manners, and lastly singlet oxygen was scavenged in dose-dependent manners. Three other free radicals were not scavenged by all of the four local anesthetics; -butoxyl radical was scavenged by all the anesthetics examined but dibucaine, nitric oxide by mepivacaine but not by the other three, and tyrosyl radical by mepivacaine and lidocaine but not by the other two. Some free radicals (superoxide anion, -butyl peroxyl radical, DPPH) were not scavenged by any of the four local anesthetics. The local anesthetics were also shown to inhibit lipid peroxidation by TBARS assay. These results suggest that local anesthetics have antioxidant properties through their free radical scavenging activities.
PubMed: 37534092
DOI: 10.3164/jcbn.22-131