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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 -
Anaesthesia Apr 1969
Topics: Anesthesia, Spinal; Dibucaine; Drug and Narcotic Control; Economics; Humans; Lidocaine; Procaine; Tetracaine
PubMed: 5774706
DOI: No ID Found -
Journal of Medical Toxicology :... Mar 2010Dibucaine is a potent, long-lasting local anesthetic (LA). Topical dibucaine ointments are marketed directly to consumers in the USA without prescription. Dibucaine...
INTRODUCTION
Dibucaine is a potent, long-lasting local anesthetic (LA). Topical dibucaine ointments are marketed directly to consumers in the USA without prescription. Dibucaine ointment is intended to treat discomfort associated with sunburn, eczema, minor rashes, minor scratches, insect bites, and poison ivy and is used alone or in combination with other active ingredients to treat pain associated with hemorrhoids or other anorectal disorders. Oral dibucaine toxicosis has been reported in children and includes gastrointestinal upset and neurologic and cardiovascular dysfunction.
CASE REPORT
An 18-month-old, female, Parson Russell terrier ingested approximately 23 g of 1% dibucaine ointment (approximately 38 mg/kg dibucaine) recommended to the owner for the treatment of hemorrhoids. Onset and resolution of clinical signs were relatively rapid, 5 min and 60 min, respectively. Clinical signs included vomiting, ptyalism, whole-body muscle fasciculations, disorientation, and severe ataxia.
DISCUSSION
Oral dibucaine toxicosis in dogs is similar to oral dibucaine toxicosis in children. Dibucaine ointment poses a real and potentially serious toxicological risk to pets and thus should be stored in a safe location.
Topics: Accidents; Administration, Oral; Anesthetics, Local; Animals; Antidotes; Ataxia; Charcoal; Confusion; Dibucaine; Dog Diseases; Dogs; Female; Poisoning; Sialorrhea; Spasm; Treatment Outcome; Vomiting
PubMed: 20224995
DOI: 10.1007/s13181-010-0036-3 -
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 -
Biophysical Journal Sep 1996To study the molecular mechanisms of local anesthesia, locations of local anesthetic dibucaine in model membranes and the interactions of dibucaine with a Na+ channel...
Locations of local anesthetic dibucaine in model membranes and the interaction between dibucaine and a Na+ channel inactivation gate peptide as studied by 2H- and 1H-NMR spectroscopies.
To study the molecular mechanisms of local anesthesia, locations of local anesthetic dibucaine in model membranes and the interactions of dibucaine with a Na+ channel inactivation gate peptide have been studied by 2H- and 1H-NMR spectroscopies. The 2H-NMR spectra of dibucaine-d9 and dibucaine-d1, which are deuterated at the butoxy group and at the 3 position in its quinoline ring, respectively, have been observed in multilamellar dispersions of the lipid mixture composed of phosphatidylcholine, phosphatidylserine, and phosphatidylethanolamine. 2H-NMR spectra of deuterated palmitic acids incorporated, as a probe, into the lipid mixture containing cholesterol have also been observed. An order parameter, SCD, for each carbon segment was calculated from the observed quadrupole splittings. Combining these results, we concluded that first, the butoxy group of dibucaine is penetrating between the acyl chains of lipids in the model membranes, and second, the quinoline ring of dibucaine is located at the polar region of lipids but not at the hydrophobic acyl chain moiety. These results mean that dibucaine is situated in a favorable position that permits it to interact with a cluster of hydrophobic amino acids (Ile-Phe-Met) within the intracellular linker between domains III and IV of Na+ channel protein, which functions as an inactivation gate. To confirm whether the dibucaine molecule at the surface region of lipids can really interact with the hydrophobic amino acids, we synthesized a model peptide that includes the hydrophobic amino acids (Ac-GGQDIFMTEEQK-OH, MP-1), the amino acid sequence of which corresponds to the linker part of rat brain type IIA Na+ channel, and the one in which Phe has been substituted by Gln (MP-2), and measured 1H-NMR spectra in both phosphate buffer and phosphatidylserine liposomes. It was found that the quinoline ring of dibucaine can interact with the aromatic ring of Phe by stacking of the rings; moreover, the interaction can be reinforced by the presence of lipids. In conclusion, we wish to propose that local anesthesia originates from the pi-stacking interaction between aromatic rings of an anesthetic molecule located at the polar headgroup region of the so-called boundary lipids and of the Phe in the intracellular linker between domains III and IV of the Na+ channel protein, prolonging the inactivated state and consequently making it impossible to proceed to the resting state.
Topics: Amino Acid Sequence; Anesthetics, Local; Animals; Biophysical Phenomena; Biophysics; Cholesterol; Deuterium; Dibucaine; In Vitro Techniques; Liposomes; Magnetic Resonance Spectroscopy; Membrane Lipids; Membranes, Artificial; Models, Molecular; Molecular Structure; Oligopeptides; Palmitic Acids; Phenylalanine; Phosphatidylserines; Protons; Rats; Sodium Channel Blockers; Sodium Channels
PubMed: 8873993
DOI: 10.1016/S0006-3495(96)79327-X -
Acta Crystallographica. Section E,... Nov 2010The mol-ecular conformation of the title compound, C(20)H(29)N(3)O(2), is stabilized by an intra-molecular C-H⋯O hydrogen bond. The orientation of the amide group to...
The mol-ecular conformation of the title compound, C(20)H(29)N(3)O(2), is stabilized by an intra-molecular C-H⋯O hydrogen bond. The orientation of the amide group to the ring system is characterized by a C-C-C-O dihedral angle of 137.5 (3)°. In the crystal, inter-molecular N-H⋯O hydrogen bonds between the amide groups form C(4) chains running parallel to the a axis.
PubMed: 21589483
DOI: 10.1107/S1600536810045460