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Science Advances Jan 2022Enteroviruses are globally prevalent human pathogens responsible for many diseases. The nonstructural protein 2C is a AAA+ helicase and plays a key role in enterovirus...
Enteroviruses are globally prevalent human pathogens responsible for many diseases. The nonstructural protein 2C is a AAA+ helicase and plays a key role in enterovirus replication. Drug repurposing screens identified 2C-targeting compounds such as fluoxetine and dibucaine, but how they inhibit 2C is unknown. Here, we present a crystal structure of the soluble and monomeric fragment of coxsackievirus B3 2C protein in complex with ()-fluoxetine (SFX), revealing an allosteric binding site. To study the functional consequences of SFX binding, we engineered an adenosine triphosphatase (ATPase)–competent, hexameric 2C protein. Using this system, we show that SFX, dibucaine, HBB [2-(α-hydroxybenzyl)-benzimidazole], and guanidine hydrochloride inhibit 2C ATPase activity. Moreover, cryo–electron microscopy analysis demonstrated that SFX and dibucaine lock 2C in a defined hexameric state, rationalizing their mode of inhibition. Collectively, these results provide important insights into 2C inhibition and a robust engineering strategy for structural, functional, and drug-screening analysis of 2C proteins.
PubMed: 34985963
DOI: 10.1126/sciadv.abj7615 -
Journal of Medicinal Chemistry Apr 2019Enterovirus D68 (EV-D68) is an atypical nonpolio enterovirus that mainly infects the respiratory system of humans, leading to moderate-to-severe respiratory diseases. In...
Enterovirus D68 (EV-D68) is an atypical nonpolio enterovirus that mainly infects the respiratory system of humans, leading to moderate-to-severe respiratory diseases. In rare cases, EV-D68 can spread to the central nervous system and cause paralysis in infected patients, especially young children and immunocompromised individuals. There is currently no approved vaccine or antiviral available for the prevention and treatment of EV-D68. In this study, we aimed to improve the antiviral potency and selectivity of a previously reported EV-D68 inhibitor, dibucaine, through structure-activity relationship studies. In total, 60 compounds were synthesized and tested against EV-D68 using the viral cytopathic effect assay. Three compounds 10a, 12a, and 12c were identified to have significantly improved potency (EC < 1 μM) and a high selectivity index (>180) compared with dibucaine against five different strains of EV-D68 viruses. These compounds also showed potent antiviral activity in neuronal cells, such as A172 and SH-SY5Y cells, suggesting they might be further developed for the treatment of both respiratory infection as well as neuronal infection.
Topics: Antiviral Agents; Cell Line, Tumor; Cell Survival; Dibucaine; Drug Design; Enterovirus D, Human; Humans; Quinolines; Structure-Activity Relationship
PubMed: 30912944
DOI: 10.1021/acs.jmedchem.9b00115 -
Antimicrobial Agents and Chemotherapy Mar 2017The efficacy of antimicrobial drugs against , an intracellular bacterial pathogen, is generally first established by testing compounds against bacteria in axenic...
The efficacy of antimicrobial drugs against , an intracellular bacterial pathogen, is generally first established by testing compounds against bacteria in axenic culture. However, inside infected macrophages, bacteria encounter an environment which differs substantially from broth culture and are subject to important host-dependent pharmacokinetic phenomena which modulate drug activity. Here, we describe how pH-dependent partitioning drives asymmetric antimicrobial drug distribution in infected macrophages. Specifically, weak bases with moderate activity against (fluoxetine, sertraline, and dibucaine) were shown to accumulate intracellularly due to differential permeability and relative abundance of their ionized and nonionized forms. Nonprotonatable analogs of the test compounds did not show this effect. Neutralization of acidic organelles directly with ammonium chloride or indirectly with bafilomycin A1 partially abrogated the growth restriction of these drugs. Using high-performance liquid chromatography, we quantified the degree of accumulation and reversibility upon acidic compartment neutralization in macrophages and observed that accumulation was greater in infected than in uninfected macrophages. We further demonstrate that the efficacy of a clinically used compound, clofazimine, is augmented by pH-based partitioning in a macrophage infection model. Because the parameters which govern this effect are well understood and are amenable to chemical modification, this knowledge may enable the rational development of more effective antibiotics against tuberculosis.
Topics: Ammonium Chloride; Anesthetics, Local; Antitubercular Agents; Biological Transport; Clofazimine; Dibucaine; Fluoxetine; Humans; Hydrogen-Ion Concentration; Macrolides; Macrophages; Microbial Sensitivity Tests; Mycobacterium tuberculosis; Protons; Selective Serotonin Reuptake Inhibitors; Sertraline
PubMed: 28052847
DOI: 10.1128/AAC.01639-16 -
JAMA Dermatology Jan 2020Contact dermatitis in the anogenital area is associated with sleep disturbance and dyspareunia and can profoundly affect quality of life. The literature on anogenital...
IMPORTANCE
Contact dermatitis in the anogenital area is associated with sleep disturbance and dyspareunia and can profoundly affect quality of life. The literature on anogenital contact dermatitis and culprit allergens is limited. The last large-scale study on common, relevant allergens in patients with anogenital dermatitis was published in 2008.
OBJECTIVES
To characterize patients with anogenital dermatitis referred for patch testing by the North American Contact Dermatitis Group, to identify common allergens, and to explore sex-associated differences between anogenital dermatitis and allergens.
DESIGN, SETTING, AND PARTICIPANTS
A retrospective, cross-sectional analysis was conducted of the North American Contact Dermatitis Group database among 28 481 patients who underwent patch testing from January 1, 2005, to December 31, 2016, at outpatient referral clinics in the United States and Canada.
EXPOSURE
Patch testing for allergens.
MAIN OUTCOMES AND MEASURES
Currently relevant allergic patch test reactions in patients with anogenital dermatitis.
RESULTS
Of 28 481 patients tested during the study period, 832 patients (336 men and 496 women; mean [SD] age, 50.1 [26.5] years) had anogenital involvement and 449 patients (177 men and 272 women; mean [SD] age, 49.6 [17.4] years) had anogenital dermatitis only. Compared with those without anogenital involvement, there were significantly more male patients in the group with anogenital dermatitis (177 [39.4%] vs 8857 of 27 649 [32.0%]; relative risk, 1.37; 95% CI, 1.14-1.66; P < .001). In the group with anogenital involvement, female patients were significantly less likely than male patients to have allergic contact dermatitis as a final diagnosis (130 [47.8%] vs 107 [60.5%]; relative risk, 0.78; 95% CI, 0.64-0.94; P = .01), whereas a final diagnosis of other dermatoses (eg, lichen planus, lichen sclerosus, or lichen simplex chronicus) was more frequent for female patients than for male patients (67 [24.6%] vs 28 [15.8%]; relative risk, 1.54; 95% CI, 1.02-2.31; P = .03). Of the 449 patients in the group with anogenital involvement only, 227 (50.6%) had 1 or more relevant reaction with patch testing. Allergens that were statistically significantly more common in patients with anogenital involvement compared with those without anogenital involvement included medicaments such as dibucaine (10 of 250 patients tested [4.0%] vs 32 of 17 494 patients tested [0.2%]; relative risk, 22.74; 95% CI, 11.05-46.78; P < .001) and preservatives such as methylchloroisothiazolinone and methylisothiazolinone (30 of 449 patients tested [6.7%] vs 1143 of 27 599 patients tested [4.1%]; relative risk, 1.61; 95% CI, 1.14-2.41; P = .008). A total of 152 patients met the definition for anogenital allergic contact dermatitis, which is defined as anogenital involvement only, allergic contact dermatitis as the only diagnosis, and 1 or more positive reaction of current clinical relevance.
CONCLUSIONS AND RELEVANCE
For patients with anogenital involvement only who were referred for patch testing, male patients were more likely to have allergic contact dermatitis, whereas female patients were more likely to have other dermatoses. Common allergens or sources consisted of those likely to contact the anogenital area. For individuals with anogenital involvement suspected of having allergic contact dermatitis, reactions to preservatives, fragrances, medications (particularly topical anesthetics), and topical corticosteroids should be tested.
Topics: Administration, Cutaneous; Adult; Aged; Allergens; Anesthetics; Anus Diseases; Cosmetics; Cross-Sectional Studies; Dermatitis, Allergic Contact; Female; Genital Diseases, Female; Genital Diseases, Male; Glucocorticoids; Humans; Male; Middle Aged; North America; Patch Tests; Quality of Life; Retrospective Studies; Young Adult
PubMed: 31774454
DOI: 10.1001/jamadermatol.2019.3844 -
The Journal of Biological Chemistry 2021The mitochondrial calcium uniporter (MCU) and cyclophilin D (CyD) are key players in induction of the permeability transition pore (PTP), which leads to mitochondrial...
The mitochondrial calcium uniporter (MCU) and cyclophilin D (CyD) are key players in induction of the permeability transition pore (PTP), which leads to mitochondrial depolarization and swelling, the major signs of Ca-induced mitochondrial damage. Mitochondrial depolarization inhibits ATP production, whereas swelling results in the release of mitochondrial pro-apoptotic proteins. The extent to which simultaneous deletion of MCU and CyD inhibits PTP induction and prevents damage of brain mitochondria is not clear. Here, we investigated the effects of MCU and CyD deletion on the propensity for PTP induction using mitochondria isolated from the brains of MCU-KO, CyD-KO, and newly created MCU/CyD-double knockout (DKO) mice. Neither deletion of MCU nor of CyD affected respiration or membrane potential in mitochondria isolated from the brains of these mice. Mitochondria from MCU-KO and MCU/CyD-DKO mice displayed reduced Ca uptake and diminished extent of PTP induction. The Ca uptake by mitochondria from CyD-KO mice was increased compared with mitochondria from WT mice. Deletion of CyD prevented mitochondrial swelling and resulted in transient depolarization in response to Ca, but it did not prevent Ca-induced delayed mitochondrial depolarization. Mitochondria from MCU/CyD-DKO mice did not swell in response to Ca, but they did exhibit mild sustained depolarization. Dibucaine, an inhibitor of the Ca-activated mitochondrial phospholipase A2, attenuated and bovine serum albumin completely eliminated the sustained depolarization. This suggests the involvement of phospholipase A2 and free fatty acids. Thus, in addition to induction of the classical PTP, alternative deleterious mechanisms may contribute to mitochondrial damage following exposure to elevated Ca.
Topics: Animals; Brain; Calcium; Calcium Channels; Peptidyl-Prolyl Isomerase F; Gene Knockout Techniques; Mice; Mice, Knockout; Mitochondria; Mitochondrial Proteins
PubMed: 33864812
DOI: 10.1016/j.jbc.2021.100669 -
Molecular Pharmaceutics Jun 2023In this study, we investigated the effects of drugs on membrane function in which lipid peroxidation was inhibited by the antioxidant Trolox (TRO) in liposomes...
In this study, we investigated the effects of drugs on membrane function in which lipid peroxidation was inhibited by the antioxidant Trolox (TRO) in liposomes containing egg yolk lecithin. Local anesthetics (LAs), such as lidocaine (LID) and dibucaine (DIB), were used as model drugs. The effect of LAs on the inhibitory activity of TRO was evaluated by calculating the p from the inhibition constant calculated by curve fitting. p indicates the strength of TRO membrane protective function. p indicates the strength of LA activity. LAs inhibited lipid peroxidation in a dose-dependent manner and decreased p. The effect of DIB on p was 1.9 times more than that of LID. This result indicated that LA may improve the fluidity of the membrane, which may facilitate the migration of TRO from the membrane to the liquid phase. As a result, TRO is less likely to suppress lipid peroxidation within the lipid membrane, possibly resulting in a decrease in p. The effect of TRO on p was found to be similar in both, indicating that it did not depend on the type of the model drug. These results suggest that our developed procedure successfully quantified the effects of LAs on lipid membrane functions. We were able to obtain the characteristics of model drugs independent of TRO by simultaneously measuring and analyzing the lipid peroxidation inhibitory activities of TRO and model drugs in liposomes.
Topics: Anesthetics, Local; Liposomes; Lipid Peroxidation; Antioxidants; Dibucaine; Lidocaine; Lipids
PubMed: 37104048
DOI: 10.1021/acs.molpharmaceut.2c01053 -
Journal of Pharmacy & Bioallied Sciences Jun 2021To compare and analyze the clinical adequacy of two topical anesthetic gels, Precaine (8% lidocaine + 0.8% dibucaine) and Precaine B (20% benzocaine) in children before...
AIM
To compare and analyze the clinical adequacy of two topical anesthetic gels, Precaine (8% lidocaine + 0.8% dibucaine) and Precaine B (20% benzocaine) in children before intraoral local anesthetic injections.
MATERIALS AND METHODS
This clinical study included thirty children who needed an inferior alveolar nerve block. They were divided into three groups: Group A: Precaine topical gel group, Group B: Precaine B topical gel Group, Group C: no anesthetic topical gel group (control group). These two effective topical gels were applied before giving intraoral local anesthesia, and afterward, the child's pain response was surveyed utilizing the Wong-Baker Faces Pain Rating Scale. The scores obtained were subjected to statistical analysis.
RESULTS
Intergroup comparison showed a significant mean difference between the control group and Precaine group ( > 0.05) as well as Precaine B group ( > 0.05). However, there is no significant difference obtained between Group A and Group B ( < 0.05).
CONCLUSION
It is psychologically and clinically beneficial to apply a topical anesthetic agent before injecting any intraoral anesthesia. In this study, both anesthetic gels showed a nonsignificant difference in reducing inferior alveolar injection pain, but Precaine B shows more promising results than Precaine.
PubMed: 34447172
DOI: 10.4103/jpbs.JPBS_772_20 -
Antimicrobial Agents and Chemotherapy May 2016Enteroviruses (EVs) represent many important pathogens of humans. Unfortunately, no antiviral compounds currently exist to treat infections with these viruses. We...
Enteroviruses (EVs) represent many important pathogens of humans. Unfortunately, no antiviral compounds currently exist to treat infections with these viruses. We screened the Prestwick Chemical Library, a library of approved drugs, for inhibitors of coxsackievirus B3, identified pirlindole as a potent novel inhibitor, and confirmed the inhibitory action of dibucaine, zuclopenthixol, fluoxetine, and formoterol. Upon testing of viruses of several EV species, we found that dibucaine and pirlindole inhibited EV-B and EV-D and that dibucaine also inhibited EV-A, but none of them inhibited EV-C or rhinoviruses (RVs). In contrast, formoterol inhibited all enteroviruses and rhinoviruses tested. All compounds acted through the inhibition of genome replication. Mutations in the coding sequence of the coxsackievirus B3 (CV-B3) 2C protein conferred resistance to dibucaine, pirlindole, and zuclopenthixol but not formoterol, suggesting that 2C is the target for this set of compounds. Importantly, dibucaine bound to CV-B3 protein 2C in vitro, whereas binding to a 2C protein carrying the resistance mutations was reduced, providing an explanation for how resistance is acquired.
Topics: Antiviral Agents; Carbazoles; Carrier Proteins; Clopenthixol; Dibucaine; Enterovirus; Fluoxetine; Formoterol Fumarate; HeLa Cells; Humans; Rhinovirus; Viral Nonstructural Proteins; Viral Proteins; Virus Replication
PubMed: 26856848
DOI: 10.1128/AAC.02182-15 -
Revista Brasileira de Ginecologia E... May 2021The diagnosis of genital ulcers remains a challenge in clinical practice. Lipschütz ulcer is a non-sexually transmitted rare and, probably, underdiagnosed condition,...
The diagnosis of genital ulcers remains a challenge in clinical practice. Lipschütz ulcer is a non-sexually transmitted rare and, probably, underdiagnosed condition, characterized by the sudden onset of vulvar edema along with painful necrotic ulcerations. Despite its unknown incidence, this seems to be an uncommon entity, with sparse cases reported in the literature. We report the case of an 11-year-old girl who presented at the emergency department with vulvar ulcers. She denied any sexual intercourse. The investigation excluded sexually transmitted infections, so, knowledge of different etiologies of non-venereal ulcers became essential. The differential diagnoses are extensive and include inflammatory processes, drug reactions, trauma, and malignant tumors. Lipschütz ulcer is a diagnosis of exclusion. With the presentation of this case report, the authors aim to describe the etiology, clinical course, and outcomes of this rare disease, to allow differential diagnosis of genital ulceration.
Topics: Administration, Topical; Anti-Infective Agents, Local; Child; Diagnosis, Differential; Dibucaine; Epstein-Barr Virus Infections; Female; Humans; Rare Diseases; Treatment Outcome; Ulcer; Vulvar Diseases
PubMed: 34077985
DOI: 10.1055/s-0041-1729147 -
Indian Journal of Anaesthesia Jul 2017Dibucaine, a potent and toxic local anaesthetic, although currently withdrawn by the United States Food and Drug Administration for use as a spinal anaesthetic,...
Dibucaine, a potent and toxic local anaesthetic, although currently withdrawn by the United States Food and Drug Administration for use as a spinal anaesthetic, continues to remain available in many over-the-counter topical formulations. Systemic toxicity following oral ingestion of local anaesthetics is rare. We report a case of accidental ingestion of dibucaine (ear drops) in a 7-year-old child who developed diplopia, giddiness, ventricular premature contractions and a right bundle branch block. We also present a brief discussion on the pharmacologic and toxicity profile of dibucaine, the Naranjo algorithm for assessing causality in case of adverse drug reactions and a review of current guidelines on the management of local anaesthetic systemic toxicity.
PubMed: 28794532
DOI: 10.4103/ija.IJA_166_17