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1.
Structure ; 32(9): 1454-1464.e3, 2024 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-39025068

RESUMEN

The Pseudomonas aeruginosa lipase PaL catalyzes the stereoselective hydrolysis of menthyl propionate to produce L-menthol. The lack of a three-dimensional structure of PaL has so far prevented a detailed understanding of its stereoselective reaction mechanism. Here, the crystal structure of PaL was determined at a resolution of 1.80 Å by single-wavelength anomalous diffraction. In the apo-PaL structure, the catalytic His302 is located in a long loop on the surface that is solvent exposed. His302 is distant from the other two catalytic residues, Asp274 and Ser164. This configuration of catalytic residues is unusual for lipases. Using metadynamics simulations, we observed that the enzyme undergoes a significant conformational change upon ligand binding. We also explored the catalytic and stereoselectivity mechanisms of PaL by all-atom molecular dynamics simulations. These findings could guide the engineering of PaL with an improved diastereoselectivity for L-menthol production.


Asunto(s)
Dominio Catalítico , Lipasa , Simulación de Dinámica Molecular , Pseudomonas aeruginosa , Pseudomonas aeruginosa/enzimología , Lipasa/química , Lipasa/metabolismo , Cristalografía por Rayos X , Proteínas Bacterianas/química , Proteínas Bacterianas/metabolismo , Conformación Proteica , Especificidad por Sustrato , Estereoisomerismo , Unión Proteica
2.
Dig Dis Sci ; 69(3): 922-932, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38170335

RESUMEN

BACKGROUND: L-Menthol sprayed on early gastric cancer (EGC) has been reported to improve the visibility of the lesion. However, its impact when used in combination with novel image-enhanced endoscopy has not been investigated. AIM: This study aimed to evaluate the visual effect of spraying L-menthol on EGC under linked color imaging (LCI). METHODS: This open-label, single-arm, prospective study investigated the color difference between EGC and the surrounding mucosa (ΔEG) before and after spraying L-menthol. The primary endpoint was the percentage of lesions with ΔEG ≥ 5 on LCI. The percentage of lesions with ΔEG ≥ 5 on white light imaging (WLI) and blue laser imaging (BLI), ΔEG before and after spraying L-menthol, and percentage of lesions with increased ΔEG after spraying L-menthol constituted the secondary endpoints. RESULTS: Sixty patients were included in the final analysis. 100% lesions had ΔEG ≥ 5, both before and after spraying L-menthol on LCI, with similar results observed in WLI as well as BLI. The median ΔEG on LCI, WLI, and BLI increased after spraying L-menthol (LCI: 16.9 vs. 21.5, p < 0.01; WLI: 10.4 vs. 13.4, p < 0.01; BLI; 12.1 vs. 15.7, before and after, respectively, p < 0.01); and LCI demonstrated the highest percentage of lesions with increased ΔEG (LCI, WLI, and BLI: 98.3%, 81.7%, and 76.7%, respectively, p < 0.01). CONCLUSION: Although spraying L-menthol did not improve the visibility of EGC under LCI observation, a significant increase in ΔEG was observed in LCI (jRCTs 021200027).


Asunto(s)
Neoplasias Gástricas , Humanos , Neoplasias Gástricas/diagnóstico por imagen , Neoplasias Gástricas/patología , Mentol , Estudios Prospectivos , Endoscopía , Membrana Mucosa/patología , Color , Mucosa Gástrica/diagnóstico por imagen , Mucosa Gástrica/patología
3.
J Agric Food Chem ; 72(4): 2277-2286, 2024 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-38235660

RESUMEN

Enzymatic kinetic resolution is a promising way to produce l-menthol. However, the properties of the reported biocatalysts are still unsatisfactory and far from being ready for industrial application. Herein, a para-nitrobenzylesterase (pnbA) gene from Bacillus subtilis was cloned and expressed to produce l-menthol from d,l-menthyl acetate. The highest enantiomeric excess (ee) value of the product generated by pnbA was only approximately 80%, with a high conversion rate (47.8%) of d,l-menthyl acetate with the help of a cosolvent, indicating high catalytic activity but low enantioselectivity (E = 19.95). To enhance the enantioselectivity and catalytic efficiency of pnbA to d,l-menthyl acetate in an organic solvent-free system, site-directed mutagenesis was performed based on the results of molecular docking. The F314E/F315T mutant showed the best catalytic properties (E = 36.25) for d,l-menthyl acetate, with 92.11% ee and 30.58% conversion of d,l-menthyl acetate. To further improve the properties of pnbA, additional mutants were constructed based on the structure-guided triple-code saturation mutagenesis strategy. Finally, four mutants were screened for the best enantioselectivity (ee > 99%, E > 300) and catalytic efficiency at a high substrate concentration (200 g/L) without a cosolvent. This work provides several generally applicable biocatalysts for the industrial production of l-menthol.


Asunto(s)
Esterasas , Mentol , Esterasas/genética , Esterasas/química , Mentol/química , Bacillus subtilis/genética , Simulación del Acoplamiento Molecular , Extractos Vegetales , Acetatos
4.
Curr Res Insect Sci ; 4: 100066, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37559797

RESUMEN

Nociception is the sensory perception of noxious chemical stimuli. Repellent behavior to avoid noxious stimuli is indispensable for survival, and this mechanism has been evolutionarily conserved across a wide range of species, from mammals to insects. The transient receptor potential ankyrin 1 (TRPA1) channel is one of the most conserved noxious chemical sensors. Here, we describe the heterologous stable expression of Tribolium castaneum TRPA1 (TcTRPA1) in human embryonic kidney (HEK293) cells. The intracellular Ca2+ influx was measured when two compounds, citronellal and l-menthol, derived from plant essential oils, were applied in vitro using a fluorescence assay. The analysis revealed that citronellal evoked Ca2+ influx dose-dependently for TcTRPA1, whereas l-menthol did not. In combination with our present and previous results of the avoidance-behavioral assay at the organism level, we suggest that TcTRPA1 discriminates between these two toxic compounds, and diversification in the chemical nociception selectivity has occurred in TRPA1 channel among insect taxa.

6.
Chem Biodivers ; 20(7): e202300539, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37317940

RESUMEN

To discover novel laccase inhibitors as potential fungicides, twenty-six novel L-menthol hydrazide derivatives were designed and synthesized. In the in vitro antifungal assay, most of the target compounds displayed pronounced antifungal activity against Sclerotinia sclerotiorum, Fusarium graminearum, and Botryosphaeria dothidea. Especially, the EC50 of compounds 3 b and 3 q against B. dothidea was 0.465 and 0.622 mg/L, which was close to the positive compound fluxapyroxad (EC50 =0.322 mg/L). Scanning electron microscopy (SEM) analysis showed that compound 3 b could significantly damage the mycelial morphology of B. dothidea. In vivo antifungal experiments on apple fruits showed that 3 b exhibited excellent protective and curative effects. Furthermore, in the in vitro laccase inhibition assay, 3 b showed outstanding inhibitory activity with the IC50 value of 2.08 µM, which is much stronger than positive control cysteine and PMDD-5Y. These results indicated that this class of L-menthol derivatives could be promising leads for the discovery of laccase-targeting fungicides.


Asunto(s)
Antifúngicos , Fungicidas Industriales , Antifúngicos/farmacología , Mentol , Lacasa , Relación Estructura-Actividad , Hidrazinas
7.
Brain Sci ; 13(6)2023 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-37371396

RESUMEN

L-menthol is known to activate transient receptor potential melastatin 8 (TRPM8) and induce analgesia to thermal stimuli. However, since thermal stimulation leads to the interaction among the other TRP channels, it was unclear whether L-menthol causes analgesia to stimuli other than thermal stimuli. Therefore, we aimed to investigate whether activating TRPM8 via topical application of 10% menthol solution attenuates pain-related somatosensory-evoked potentials (pSEPs) and affects numerical rating scale (NRS) score using intra-epidermal electrical stimulation (IES). We applied 10% L-menthol or control solution on the dorsum of the right hand of 25 healthy participants. The pSEP and NRS, elicited by IES, and sensory threshold were measured before and after each solution was applied. The results showed that the topical application of 10% L-menthol solution significantly reduced N2-P2 amplitude in pSEPs compared with the control solution. Moreover, the N2 latency was significantly prolonged upon the topical application of L-menthol solution. NRS scores were similar under both conditions. These results suggest that topical application of L-menthol does not alter subjective sensation induced using IES, although it may attenuate afferent signals at free nerve endings even with stimuli that do not directly activate TRP channels.

8.
J Pharm Health Care Sci ; 9(1): 20, 2023 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-37277876

RESUMEN

BACKGROUND: It is important to design an effective formulation to enhance the skin penetration, and nanotechnologies have been used in dermal and transdermal drug delivery. In this study, we prepared formulations (gels) containing l-menthol and felbinac (FEL) solid nanoparticles (FEL-NP gel) for topical application, and investigated the local and systemic absorption of the prepared FEL-NP gel. METHODS: FEL solid nanoparticles were obtained by bead milling of FEL powder (microparticles), and a topical formulation (FEL-NP gel) consisting of 1.5% FEL solid nanoparticles), 2% carboxypolymethylene, 2% l-menthol, 0.5% methylcellulose, and 5% 2-hydroxypropyl-ß-cyclodextrin (w/w %) were prepared. RESULTS: The particle size of FEL nanoparticles was 20-200 nm. The released FEL concentration from FEL-NP gel was significantly higher than that from FEL gel without bead mill treatment (carboxypolymethylene gel in which FEL microparticles (MPs) instead of FEL nanoparticles were incorporated, FEL-MP gel), and FEL was released as nanoparticles from the gel. Moreover, both transdermal penetration and percutaneous absorption of FEL-NP gel were significantly increased compared with those of FEL-MP gel, and the area under the FEL concentration-time curve (AUC) of FEL-NP gels was 1.52- and 1.38-fold of commercially available FEL ointment and FEL-MP gel, respectively. In addition, after 24 h of treatment, the FEL content in rat skin treated with FEL-NP gels was 1.38- and 2.54-fold higher than that when treated with commercially available FEL ointment and FEL-MP gel, respectively. Moreover, the enhanced skin penetration of FEL-NP gels was significantly attenuated by inhibition of energy-dependent endocytosis, such as clathrin-mediated endocytosis. CONCLUSIONS: We successfully prepared a topically applied carboxypolymethylene gel containing FEL nanoparticles. In addition, we observed that the endocytosis pathway was mainly related to the high skin penetration of FEL nanoparticles, and FEL-NP gel application resulted in high local tissue concentration and systemic absorption of FEL. These findings provide useful information for the design of topically applied nanoformulations against inflammation by providing local and systemic effects.

9.
Respir Physiol Neurobiol ; 311: 104036, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36804472

RESUMEN

Breathlessness is a centrally processed symptom, as evidenced by activation of distinct brain regions such as the insular cortex and amygdala, during the anticipation and/or perception of breathlessness. Inhaled L-menthol or blowing cool air to the face/nose, both selective trigeminal nerve (TGN) stimulants, relieve breathlessness without concurrent improvements in physiological outcomes (e.g., breathing pattern), suggesting a possible but hitherto unexplored central mechanism of action. Four databases were searched to identify published reports supporting a link between TGN stimulation and activation of brain regions involved in the anticipation and/or perception of breathlessness. The collective results of the 29 studies demonstrated that TGN stimulation activated 12 brain regions widely implicated in the anticipation and/or perception of breathlessness, including the insular cortex and amygdala. Inhaled L-menthol or cool air to the face activated 75% and 33% of these 12 brain regions, respectively. Our findings support the hypothesis that TGN stimulation contributes to breathlessness relief by altering the activity of brain regions involved in its central neural processing.


Asunto(s)
Nervio Olfatorio , Percepción Olfatoria , Humanos , Mentol , Encéfalo/fisiología , Disnea , Percepción , Nervio Trigémino/fisiología , Imagen por Resonancia Magnética , Percepción Olfatoria/fisiología
10.
Mol Divers ; 27(1): 323-340, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-35467269

RESUMEN

Cervical cancer is a major cause of gynecological related mortalities in developing countries. Cisplatin, a potent chemotherapeutic agent used for treating advanced cervical cancer exhibits side effects and resistance development. The current study was aimed to investigate the repurposing of l-menthol as a potential therapeutic drug against cervical cancer. L-menthol was predicted to be non-toxic with good pharmacokinetic properties based on SwissADME and pkCSM analysis. Subsequently, 543 and 1664 targets of l-menthol and cervical cancer were identified using STITCH, BATMAN-TCM, PharmMapper and CTD databases. STRING and Cytoscape analysis of the merged protein-protein interaction network revealed 107 core targets of l- menthol against cervical cancer. M-CODE identified highly connected clusters between the core targets which through KEGG analysis were found to be enriched in pathways related to apoptosis and adherence junctions. Molecular docking showed that l- menthol targeted E6, E6AP and E7 onco-proteins of HPV that interact and inactivate TP53 and Rb1 in cervical cancer, respectively. Molecular docking also showed good binding affinity of l-menthol toward proteins associated with apoptosis and migration. Molecular dynamics simulation confirmed stability of the docked complexes. In vitro analysis confirmed that l-menthol was cytotoxic towards cervical cancer CaSki cells and altered expression of TP53, Rb1, CDKN1A, E2F1, NFKB1, Akt-1, caspase-3, CDH1 and MMP-2 genes identified through network pharmacology approach. Schematic representation of the work flow depicting the potential of l-menthol to target cervical cancer.


Asunto(s)
Mentol , Neoplasias del Cuello Uterino , Femenino , Humanos , Mentol/farmacología , Simulación del Acoplamiento Molecular , Farmacología en Red , Neoplasias del Cuello Uterino/tratamiento farmacológico
11.
Eur J Sport Sci ; 23(9): 1913-1921, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35997234

RESUMEN

ABSTRACTThis study aimed to clarify the contribution of L-menthol administration to endurande exercise capacity. Thirteen male runners (age, 35.8 ± 7.8 years; peak oxygen uptake, 62.7 ± 6.8 mL kg-1 min-1) ran on treadmills at fixed intensities of their anaerobic thresholds to exhaustion. All participants underwent three trials-water ingestion (W-IG), L-menthol mouth rinsing (M-MR), and L-menthol ingestion (M-IG)- in a random order every 5 min while running. Breathing comfort (BC) was measured immediately after fluid intake. Dyspnea threshold against external inspiratory resistance was examined before and after the running test. The running time with M-IG (1683.9 ± 520.3 s) was longer than that with W-IG (1410.2 ± 465.9 s, effect size [ES] = 0.55). BC with M-IG (2.00 ± 0.74) was higher than that with W-IG (0.42 ± 0.79) at exhaustion (ES > 2.00). The dyspnea threshold after running decreased to 19.2 ± 7.6 cm H2O L-1 s-1 with W-IG, whereas that with M-MR (26.2 ± 6.5 cm H2O L-1 s-1) and M-IG (29.2 ± 2.8 cm H2O L-1 s-1) remained high (p for interaction < 0.001). M-IG facilitated BC during running, improved endurance capacity, and prevented decreases in the dyspnea threshold against external inspiratory resistance after exhaustive running.HighlightsL-menthol ingestion facilitated breathing comfort during high intensity endurance running and improved exhaustive endurance running capacity.Even after exhaustion, L-menthol solution relieved dyspnea sensitivity against external inspiratory resistance.L-menthol ingestion might help athletes improve their endurance running capacity.


Asunto(s)
Mentol , Resistencia Física , Humanos , Masculino , Adulto , Estudios Cruzados , Umbral Anaerobio , Extractos Vegetales , Disnea
12.
Molecules ; 27(18)2022 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-36144758

RESUMEN

Fragrances have been widely used in many customer products to improve the sensory quality and cover flavor defects. The key to the successful application of fragrance is to realize controlled fragrance release, which relies on the use of an appropriate carrier for fragrance. An ideal fragrance carrier helps to achieve the stable storage and controlled release of fragrance. In this work, a novel composite fragrance carrier with MIL-101 (Cr) as the fragrance host and cellulose acetate fiber (CAF) as the protective shell was developed. The encapsulation effect of MIL-101 (Cr) and the protective function of the CAF shell significantly improved the storage stability of L-menthol (LM). Only 5 wt % of LM was lost after 40 days of storage at room temperature. Encapsulated LM could also be effectively released upon heating due to the thermal responsiveness of CAF. In addition, the composite carrier was highly stable with neglectable Cr leaching under different conditions. The results of this work showed that the developed composite carrier could be a promising carrier for the thermally triggered release of fragrance.


Asunto(s)
Estructuras Metalorgánicas , Perfumes , Acetatos , Celulosa/análogos & derivados , Preparaciones de Acción Retardada , Mentol , Terpenos
13.
Molecules ; 27(16)2022 Aug 18.
Artículo en Inglés | MEDLINE | ID: mdl-36014511

RESUMEN

The deep eutectic solvent (DES)-based biocatalysis of l-menthol acylation was designed for the production of fatty acid l-menthyl ester (FME) using fatty acid methyl ester (FAME). The biocatalytic reaction was assisted by a lipase enzyme in the DES reaction medium. ւՒ-menthol and fatty acids (e.g., CA-caprylic acid; OA-oleic acid; LiA-linoleic acid; and LnA-linolenic acid) were combined in the binary mixture of DES. In this way, the DES provided a nonpolar environment for requested homogeneity of a biocatalytic system with reduced impact on the environment. The screening of lipase enzyme demonstrated better performance of immobilized lipase compared with powdered lipase. The performance of the biocatalytic system was evaluated for different DES compositions (type and concentration of the acid component). l-menthol:CA = 73:27 molar ratio allowed it to reach a maximum conversion of 95% methyl lauric ester (MLE) using a NV (Candida antarctica lipase B immobilized on acrylic resin) lipase biocatalyst. The recyclability of biocatalysts under optimum conditions of the system was also evaluated (more than 80% recovered biocatalytic activity was achieved for the tested biocatalysts after five reaction cycles). DES mixtures were characterized based on differential scanning calorimetry (DSC) and refractive index analysis.


Asunto(s)
Ésteres , Mentol , Acilación , Biocatálisis , Enzimas Inmovilizadas/química , Ácidos Grasos , Lipasa/química , Mentol/química
14.
Food Chem ; 396: 133728, 2022 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-35870240

RESUMEN

The extraction of curcuminoids and aromatic (ar)-turmerone from Curcuma longa L. using organic solvents produces chemical waste, and is therefore incompatible with food applications. To address this issue, this study presents the design of hydrophobic deep eutectic solvents (HDESs) and HDES-based microemulsions. Using the response surface methodology (RSM), the optimal extraction conditions were identified as follows: HDES = OA:menthol (1:3.6 M ratio), solid-to-liquid ratio = 10:1 (mg/mL), and extraction duration = 90 min (prediction accuracy ≥ 85 %). Under these conditions, the HDES extraction yields of bisdemethoxycurcumin, demethoxycurcumin, curcumin, and ar-turmerone were 2.49 ± 0.25, 5.61 ± 0.45, 9.40 ± 0.86, and 3.83 ± 0.19 % (w/w, dry basis), respectively, while those obtained using the HDES-based microemulsion were 2.10 ± 0.18, 6.31 ± 0.48, 12.6 ± 1.20, and 2.58 ± 0.19 % (w/w, dry basis), respectively. The HDES and its microemulsions are more effective and environmentally friendly than conventional organic solvents for the extraction of curcuminoids and ar-turmerone, and these solvents are also compatible with food and pharmaceutical formulations.


Asunto(s)
Curcuma , Curcumina , Curcuma/química , Curcumina/química , Disolventes Eutécticos Profundos , Diarilheptanoides/química , Cetonas , Sesquiterpenos , Solventes/química
15.
BMC Gastroenterol ; 22(1): 105, 2022 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-35255832

RESUMEN

BACKGROUND: A randomized, placebo-controlled clinical trial (FDREST) of a novel formulation of caraway oil and L-menthol (COLM-SST) demonstrated symptom relief in patients with functional dyspepsia (FD). Two follow-up studies were conducted to evaluate patient satisfaction, self-regulated dosing, and long-term safety data: FDACT, Functional Dyspepsia Adherence and Compliance Trial, and FDSU36, Functional Dyspepsia Safety Update at 36 months. METHODS: A patient reported outcomes (PRO) questionnaire was designed and distributed online to assess real-world satisfaction and dosing frequency of open-label COLM-SST in patients with FD. A separate study analyzing voluntary safety surveillance data evaluated the frequency and severity of reported adverse events (AEs). RESULTS: A total of 600 FD patients were enrolled in the PRO study. Ninety five percent of respondents reported a major or moderate improvement in their FD symptoms and 91.7% indicated a major or moderate improvement in quality of life (QOL) using COLM-SST. Between 1 and 4 capsules were consumed daily by 91.2% of respondents, with 56.2% taking them before meals. Symptom relief was rapid, with 86.4% of respondents indicating relief within 2 h of taking COLM-SST. Few adverse events (AEs) were reported (0.0187%) by patients using COLM-SST. No serious AEs were identified. CONCLUSION: COLM-SST is safe, well tolerated, and provides rapid relief of FD symptoms. These findings, demonstrated in the FDREST trial, were further supported by a large prospective PRO study evaluating self-regulated dosing frequency, symptom improvement, and QOL. COLM-SST was well-tolerated based on review of AE data at 36 months.


Asunto(s)
Dispepsia , Mentol , Dispepsia/diagnóstico , Dispepsia/tratamiento farmacológico , Humanos , Mentol/uso terapéutico , Aceites de Plantas , Estudios Prospectivos , Calidad de Vida , Resultado del Tratamiento
16.
Artículo en Chino | WPRIM (Pacífico Occidental) | ID: wpr-934108

RESUMEN

Objective:To evaluate the effects of single spay of L-menthol (NPO-11) on suppressing gastric peristalsis during upper gastrointestinal endoscopy and the influencing factor.Methods:This study was a multicenter, randomized, double-blind, placebo-parallel controlled study. The eligible patients were randomly divided into two groups by randomized blocks. Patients received local spray of either NPO-11 (160 mg L-menthol) or placebo 20 mL during upper gastrointestinal endoscopy. The gastric peristalsis was recorded and evaluated before, 2 minutes after and at the end of endoscopy. The complexity of the procedure was evaluated by the researchers. The influencing factors for antiperistaltic effect of NPO-11 were analyzed.Results:A total of 220 patients were enrolled from five research centers. There were 109 cases in the NPO-11 group and 111 cases in the placebo group. The baseline data of the two groups were similar and comparable. The proportion of patients with grade 1 peristalsis at 2 minutes after the treatment and at the end of endoscopy was significantly higher in the NPO-11 group than that in the placebo group [40.37% (44/109) VS 16.22% (18/111), χ2=15.93, P<0.001]. Compared with the placebo group, the proportions of weak peristalsis (grade 1 and 2) were higher in the NPO-11 group at 2 minutes after the treatment [67.89% (74/109) VS 46.85% (52/111)] and at the end of endoscopy [79.82% (87/109) VS 48.65% (54/111)]. Subgroup analysis showed that the inhibitory effect of NPO-11 on gastric peristalsis was more significant in Helicobacter pylori antibody positive group. Conclusion:Local spray of NPO-11 can effectively inhibit gastric peristalsis during upper gastrointestinal endoscopy, and its effect is more significant in Helicobacter pylori antibody positive group. It could be recommended for no obvious adverse reactions , its safety, and the convenient procedure.

17.
Toxics ; 9(12)2021 Dec 09.
Artículo en Inglés | MEDLINE | ID: mdl-34941780

RESUMEN

It has been demonstrated that propylene glycol (PG), vegetable glycerin (VG), and flavoring chemicals can thermally degrade to form carbonyls during vaping, but less is known about carbonyl emissions produced by transformation of flavoring chemicals and the interactive effects among e-liquid constituents. This study characterized carbonyl composition and levels in vaping emissions of PG-VG (e-liquid base solvents) and four e-liquid formulations flavored with trans-2-hexenol, benzyl alcohol, l-(-)-menthol, or linalool. Utilizing gas chromatography (GC)- and liquid chromatography (LC)-mass spectrometry (MS) methods, 14 carbonyls were identified and quantified. PG-VG emitted highest levels of formaldehyde, acetaldehyde, and acrolein. However, flavored e-liquids contributed to the production of a wider variety of carbonyls, with some carbonyls directly corresponding to the oxidation of alcohol moieties in flavoring compounds (e.g., trans-2-hexenol and benzyl alcohol transformed into trans-2-hexenal and benzaldehyde, respectively). Detections of formaldehyde-GSH and trans-2-hexenal-GSH adducts signify interactions of carbonyls with biological nucleophiles. The global reactivity descriptors (I, A, µ, η, and ω) and condensed Fukui parameters (fk0, fk-, fk+, and dual-descriptor) were computed to elucidate site reactivities of selected simple and α,ß-unsaturated carbonyls found in vaping emissions. Overall, this study highlights carbonyl emissions and reactivities and their potential health risk effects associated with vaping.

18.
Int J Mol Sci ; 22(19)2021 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-34639049

RESUMEN

The ability of sodium caprylate and l-menthol to fluidize phospholipid bilayers composed of lipids simulating the buccal epithelium was investigated using electron spin resonance (ESR) to evaluate the action of these agents as permeation enhancers. 5-Doxyl stearic acid (5-DSA) and 16-doxyl stearic acid (16-DSA) were used as spin labels to identify alterations in membrane fluidity near the polar head groups or inner acyl regions of the lipid bilayer, respectively. The molecular motion of both 5-DSA and 16-DSA showed increased disorder near the polar and inner hydrophobic regions of the bilayer in the presence of sodium caprylate suggesting fluidization in both the regions, which contributes to its permeation enhancing effects. L-menthol decreased the order parameter for 16-DSA, showing membrane fluidization only in the inner acyl regions of the bilayer, which also corresponded to its weaker permeation enhancing effects. The rapid evaluation of changes in fluidity of the bilayer in the presence of potential permeation enhancers using ESR enables improved selection of effective permeation enhancers and enhancer combinations based on their effect on membrane fluidization.


Asunto(s)
Caprilatos/farmacología , Espectroscopía de Resonancia por Spin del Electrón , Fluidez de la Membrana/efectos de los fármacos , Mentol/farmacología , Mucosa Bucal/efectos de los fármacos , Mucosa Bucal/metabolismo , Permeabilidad de la Membrana Celular/efectos de los fármacos , Óxidos N-Cíclicos/química , Óxidos N-Cíclicos/farmacología , Espectroscopía de Resonancia por Spin del Electrón/métodos , Membrana Dobles de Lípidos , Liposomas , Lípidos de la Membrana/química , Lípidos de la Membrana/metabolismo , Fosfolípidos/química , Fosfolípidos/metabolismo
19.
Heliyon ; 7(6): e07329, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-34195432

RESUMEN

The present study used a binding assay to identify novel target biomolecules of l-menthol ([-]-menthol) that promote mouse ambulation. Among 88 different ligands to specific biomolecules examined, 0.1 mM l-menthol inhibited the binding of 13 ligands with relatively high inhibition rates. The assays showed that l-menthol acts on calcium channels, sodium channels, γ-aminobutyric acid type A (GABAA) receptor, GABA transporter, dopamine transporter, dopamine D4 receptor, adenosine A2a receptor, α2A-adrenergic receptor, histamine H2 receptor, bombesin receptor, angiotensin AT1 receptor, vasopressin V2 receptor, and leukotriene B4 receptor over a similar concentration range. The inhibition constant (Ki) for l-menthol inhibition of binding of [3H]-WIN35,428 to the human recombinant dopamine transporter was 6.15 × 10-4 mol/L. The Ki for l-menthol inhibition of binding of [3H]-ethynylbicycloorthobenzoate (EBOB), a ligand of GABAA receptor picrotoxin site, was 2.88 × 10-4 mol/L. These results should aid future research by providing clues for investigating the mechanisms underlying l-menthol activities, including the ambulation-promoting effect. The present results suggest that the dopamine transporter, adenosine A2a receptor, dopamine D4 receptor, α2A-adrenergic receptor, and GABAA receptor are promising candidate molecules that are involved in the mechanisms underlying the psychostimulant-like effect of l-menthol.

20.
Int J Mol Sci ; 22(10)2021 May 12.
Artículo en Inglés | MEDLINE | ID: mdl-34066280

RESUMEN

We previously designed a Carbopol gel formulation (N-IND/MEN) based on a combination of indomethacin solid nanoparticles (IND-NPs) and l-menthol, and we reported that the N-IND/MEN showed high transdermal penetration. However, the detailed mechanism for transdermal penetration of IND-NPs was not clearly defined. In this study, we investigated whether endocytosis in the skin tissue of rat and Göttingen minipig is related to the transdermal penetration of IND-NPs using pharmacological inhibitors of endocytosis. The pharmacological inhibitors used in this study are as follows: 54 µM nystatin, a caveolae-mediated endocytosis (CavME) inhibitor; 40 µM dynasore, a clathrin-mediated endocytosis (CME) inhibitor; and 2 µM rottlerin, a micropinocytosis (MP) inhibitor. The N-IND/MEN was prepared by a bead mill method, and the particle size of solid indomethacin was 79-216 nm. In both rat and Göttingen minipig skin, skin penetration of approximately 80% IND-NPs was limited by the stratum corneum (SC), although the penetration of SC was improved by the combination of l-menthol. On the other hand, the treatment of nystatin and dynasore decreased the transdermal penetration of indomethacin in rats and Göttingen minipigs treated with N-IND/MEN. Moreover, in addition to nystatin and dynasore, rottlerin attenuated the transdermal penetration of IND-NPs in the Göttingen minipigs' skin. In conclusion, we found that l-menthol enhanced the SC penetration of IND-NPs. In addition, this study suggests that the SC-passed IND-NPs are absorbed into the skin tissue by energy-dependent endocytosis (CavME, CME, and/or MP pathways) on the epidermis under the SC, resulting in an enhancement in transdermal penetration of IND-NPs. These findings provide significant information for the design of nanomedicines in transdermal formulations.


Asunto(s)
Endocitosis , Indometacina/administración & dosificación , Mentol/administración & dosificación , Nanopartículas/administración & dosificación , Absorción Cutánea , Piel/efectos de los fármacos , Administración Cutánea , Animales , Antiinflamatorios no Esteroideos/administración & dosificación , Antipruriginosos/administración & dosificación , Composición de Medicamentos , Metabolismo Energético , Masculino , Nanopartículas/química , Ratas , Porcinos , Porcinos Enanos
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