Parkinson's disease (PD) is characterized by the pathological aggregation of α-synuclein (α-syn) into β-sheet-rich fibrils, contributing to neuronal toxicity and oxidative stress. In this study, we investigated the inhibitory and disaggregating effects of Triprolidine (TC) on α-syn fibrillation through a combined experimental and computational approach. Biophysical assays, including ThT assay, DLS, and ANS assays, demonstrated that TC inhibits α-syn fibrillation in a concentration-dependent manner (IC50 ≈ 255 μM), disrupts preformed fibrils, and maintains the protein's native form. CD data further revealed that TC prevents the transition of α-syn to its toxic β-sheet-rich form and facilitates partial structural reversal during disaggregation. To elucidate the molecular mechanism of inhibition, we performed all-atom molecular dynamics (MD) simulations followed by Markov State Model (MSM) construction. The simulations revealed that TC binding remodels the conformational landscape of α-syn by stabilizing compact, disordered states and reducing the population of β-sheet-prone intermediates, particularly in the aggregation-prone NAC region. MSM analysis identified metastable states with diminished aggregation potential and reduced inter-residue contact probability, offering mechanistic insights into how TC interferes with early nucleation events. TC attenuates seeded fibrillation in a concentration-dependent manner too. Complementary cellular assays, including MTT and hemolytic assays, confirmed a significant reduction in α-syn-induced cytotoxicity upon TC treatment, with a decrease in ROS levels as confirmed by the DCFH-DA assay. Together, these findings demonstrate that TC modulates both the structural dynamics and functional toxicity of α-synuclein, and highlight its potential as a promising chemical modulator for further investigation in PD-related protein aggregation.

Biologics targeting interleukin-17 (IL-17) are widely used for moderate to severe psoriasis with great efficiency. Nonetheless, their usage has sporadically resulted in paradoxical reactions, such as eczema, sarcoidosis-like eruptions, alopecia areata, and pyoderma gangrenosum. Here, we report a case of temporary facial eczema to secukinumab with a score of 5 on the Naranjo scale, which suggests a probable drug side effect. The patient was a 32-year-old Chinese male with a history of chronic plaque psoriasis for 5 years. He was previously treated with topical steroids, calcipotriol, narrowband ultraviolet B phototherapy, and oral traditional Chinese medicine intermittently since 2020. In January of 2025, his psoriasis exacerbated and was not well controlled. The patient underwent an initial regimen of 300 mg secukinumab once weekly for 4 weeks, with significant psoriasis area and severity index (PASI) improvement, and was scheduled to continue maintenance therapy on a regimen of every 4 weeks. However, in the seventh week of the secukinumab treatment course, the patient's face developed diffuse, swollen, erythematous patches that had almost coalesced into sheets. The surface is smooth, without scales, blisters, or exudation, and accompanied by mild itching. Lab tests show elevated alanine aminotransferase (ALT) at 83.2 U/L (normal range: 9-50 U/L), slightly increased direct bilirubin at 8.48 μmol/L (normal range: 0-8.0 μmol/L). Other lab tests showed no significant abnormalities. After oral compound glycyrrhizin, olopatadine hydrochloride, triprolidine hydrochloride, and topical pimecrolimus for a week, his facial lesions were completely cleared. Liver function tests normalized following a 2-week course of polyenphosphatidylcholine. The patient delayed secukinumab administration by 2 weeks and continued 300 mg secukinumab administration on a regimen of every 4 weeks. No recurrence of similar rash or other adverse effects was observed during the subsequent follow-up period over 5 months. It is concluded that eczema could be induced temporarily by secukinumab, and maybe continued application.

Small, occasional doses of triprolidine would not be expected to cause any adverse effects in breastfed infants. Larger doses or more prolonged use may cause effects in the infant or decrease the milk supply, particularly in combination with a sympathomimetic such as pseudoephedrine or before lactation is well established. The nonsedating antihistamines are preferred alternatives.

Allergic rhinitis affects millions globally, causing significant discomfort and reducing the quality of life. This study investigates the metabolic alterations in murine mast cells (MC/9) under allergic rhinitis conditions induced by lipopolysaccharide (LPS) stimulation, employing UHPLC-QTOF-MS-based untargeted and targeted metabolomics. The analysis identified 44 significantly regulated metabolites, including histamine, leukotrienes, prostaglandins, thromboxanes, and ceramides. Key metabolic pathways such as arachidonic acid, histidine, and sphingolipid metabolisms were notably modulated. The study further examined the therapeutic effects of triprolidine and zileuton, demonstrating their capacity to reverse LPS-induced metabolic shifts. Triprolidine primarily modulated histidine and sphingolipid metabolism, while zileuton targeted arachidonic acid and sphingolipid metabolism. These findings underscore the utility of metabolomics analysis in elucidating the complex biochemical pathways involved in allergic rhinitis and highlight the potential of metabolomics for evaluating therapeutic interventions. This study enhances our understanding of mast cell metabolism in allergic responses and provides a robust model for assessing the efficacy of anti-allergic agents, paving the way for more effective treatments.

This study attempted to clarify the role of histamine H1 receptors in epilepsy by exploring the effects of agonists and inverse agonists on the rundown of the current induced by iterative applications of NMDA or GABA in primary neuronal culture. Mepyramine, a classical H1-receptor antagonist/inverse agonist, increased the NMDA current by about 40% during the first minutes of recording. This effect was concentration-dependent, maximal at 10 nM, and mimicked by triprolidine, another antagonist/inverse agonist. No endogenous histamine was detected in the cultures by a selective immunoassay; both compounds were acting as inverse agonists. Indicating a high constitutive activity of the H1 receptor in this system, histamine did not affect the NMDA rundown, including its settlement, but significantly reversed the effect of mepyramine. A similar pattern was obtained with 2,3 bromophenyl histamine, a selective H1-receptor agonist. The initial increase induced by the two inverse agonists was followed by the same rundown as in controls. H1- and NMDA receptors are colocalized in most cultured neuronal cells. Mepyramine and histamine did not affect the GABA rundown. Our findings suggest an interaction between H1- and NMDA receptors. Inactivation of the H1-receptor by its inverse agonists delays the settlement of the NMDA rundown, which may underlie their proconvulsant effect reported in clinics. Therefore, H1-receptor constitutive activity and the effect of histamine revealed in its absence, tend to facilitate the initiation of the rundown, which is consistent with the anticonvulsant properties of histamine via activation of H1-receptors reported in many studies.

The endothelial glycocalyx (EG), covering the luminal side of endothelial cells, regulates vascular permeability and senses wall shear stress. In sepsis, EG undergoes degradation leading to increased permeability and edema formation. We hypothesized that restoring EG integrity using liposomal nanocarriers of preassembled glycocalyx (LNPG) will restore normal venular permeability in lipopolysaccharide (LPS)-induced sepsis model of mice. To test this hypothesis, we designed a unique perfusion microchamber in which the permeability of isolated venules could be assessed by measuring the concentration of Evans blue dye (EBD) in microliter samples of extravascular solution (ES). Histamine-induced time- and dose-dependent increases in EBD in the ES could be measured, confirming the sensitivity of the microchamber system. Notably, the histamine-induced increase in permeability was significantly attenuated by histamine receptor (H1) antagonist, triprolidine hydrochloride. Subsequently, mice were treated with LPS or LPS + LNPG. When compared with control mice, venules from LPS-treated mice showed a significant increased permeability, which was significantly reduced by LNPG administration. Moreover, in the presence of wall shear stress, intraluminal administration of LNPG significantly reduced the permeability in isolated venules from LPS-treated mice. We have found no sex differences. In conclusion, our newly developed microchamber system allows us to quantitatively measure the permeability of isolated venules. LPS-induced sepsis increases permeability of mesenteric venules that is attenuated by in vivo LNPG administration, which also reestablished endothelial responses to shear stress. Thus, LNPG presents a promising therapeutic potential for restoring EG function and thereby mitigating vasogenic edema due to increased permeability in sepsis.NEW & NOTEWORTHY In sepsis, the degradation of the endothelial glycocalyx leads to increased venular permeability. In this study, we developed a potentially new therapeutic approach by in vivo administration of liposomal nanocarriers of preassembled glycocalyx to mice, which restored venular sensitivity to wall shear stress and permeability in lipopolysaccharide-induced sepsis, likely by restoring the integrity of the endothelial glycocalyx. Using a new microchamber system, the permeability of Evans blue dye could be quantitatively determined.

Photodegradation is widely known as a changer of both the quality and the quantity of several chemical compounds. In this study, we sought to examine the photochemical behavior of triprolidine (TRP), which is a member of the first-generation antihistamine and utilized for a relief of an allergic conditions, in an aqueous media. There are no reports focused on its potential photoproducts and photodegradation pathways in detail to the best of our knowledge. TRP photodegradation induced by ultraviolet light (UV) irradiation was monitored utilizing high-performance liquid chromatography (HPLC), and structural elucidation of the TRP photoproduct was performed by electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) and nuclear magnetic resonance (NMR). Finally, the mechanism of TRP photodegradation was speculated based on the identified photoproduct. TRP was photodegraded dependent on the irradiation time of UV in proportion to the generation of one TRP photoproduct (TRP-P). Structural determination by LC-ESI-MS/MS and NMR clarified that TRP-P was the geometrical isomer of TRP, which was formed by the cis-trans conversion of double bond. UV irradiation experiment for TRP-P revealed the conversion from it to TRP. It is clarified that cis-trans conversion between TRP and TRP-P is photo-equilibrium reaction and TRP-P is predominant under the condition as this experiment. Toxicological potencies of TRP and TRP-P might not be observed by ProTox-II in silico toxicity evaluation. This is the first study evaluating the photochemical behavior of TRP.

Epilepsy is one of the most common neurological disorders, affecting millions of patients with a substantial economic and human burden. About 30-40% of epileptic patients remain un-treated after the therapeutic option. Genetic or idiopathic epilepsy count about 40% of total epilepsy patients, showing a maximum percentage for drug-resistant epilepsy. Since the last century basic approach to understanding disease progression and drug discovery has been through the prism, exploring all possible causes and treatment options. Here we report about the gene expression-based drug repositioning study for epilepsy. Epilepsy gene expression data was retrieved from the Gene Expression Omnibus database, while drugs-associated gene expression data was retrieved from the Connectivity map (CMAP). The study predicted309 drug compounds which can alter genetic epilepsy-mediated gene signature using an in-house developed R-script. These compounds were docked against identified epilepsy targets- Voltage-gated sodium channel subunit α2 (Nav1.2); GABA receptor α1-β1; and Voltage-gated calcium channel α1G (Cav3.1)using Carbamazepine, Clonazepam, and Pregabalin as standard drugs, respectively. Twenty-one predicted drug compounds showed better binding affinity than respective standards against the selected epileptic receptors. Among these drug compounds, Ergocalciferol, Oxaprozin, Flunarizine, Triprolidine and Cyproheptadine have been previously reported for anti-epileptic activities and can be potential hits to target idiopathic epilepsy.

Acrivastine is a second-generation H1-receptor antagonist, and its structure is sensitive to ultraviolet. Four unknown and one reported degradation products can be detected in the ultraviolet radiation solutions of acrivastine. To improve the quality control of acrivastine, the photodegradation impurities were isolated and structurally elucidated. There are four new impurities (1-3 and 5), and one reported compound (4). The isolation strategy was designed as preparative high-performance liquid chromatography using a reversed phase column with volatile acid addition in the mobile phase, combined with preparative thin-layer chromatography using silica gel with alkaline addition in the mobile phase. Using the developed methods, five impurities (1-5) were efficiently purified after two or three chromatography runs with purities > 95%. The structures of compounds 1-5 are elucidated based on spectroscopy analysis of MS, and nuclear magnetic resonance spectroscopy. Using the impurity standard, the high-performance liquid chromatography method was developed and validated. The method was proved to be sensitive, accurate (Recovery% 96.1-107.7%), linear (0.15-0.75 μg/mL, R2 > 0.996), robust, and specific, and it was successfully used to determine the degradation impurities of acrivastine and its formulation.

Lupus nephritis (LN) is the most common and significant complication of systemic lupus erythematosus (SLE) due to its poor prognosis and mortality rates in SLE patients. There is a critical need for new drugs as the pathogenesis of LN remains to be elucidated and immunosuppressive therapy comes with many deficiencies. In this study, 23 hub genes (IFI6, PLSCR1, XAF1, IFI16, IFI44, MX1, IFI44L, IFIT3, IFIT2, IFI27, DDX58, EIF2AK2, IFITM1, RTP4, IFITM3, TRIM22, PARP12, IFIH1, OAS1, HERC6, RSAD2, DDX60, and MX2) were identified through bioinformatics and network analysis and are closely related to interferon production and function. Interestingly, immune cell infiltration analysis and correlation analysis demonstrate a positive correlation between the expression of 23 hub genes and monocyte infiltration in glomeruli and M2 macrophage infiltration in the tubulointerstitium of LN patients. Additionally, the CTD database, DsigDB database, and DREIMT database were used to explore the bridging role of genes in chemicals and LN as well as the potential influence of these chemicals on immune cells. After comparison and discussion, six small molecules (Acetohexamide, Suloctidil, Terfenadine, Prochlorperazine, Mefloquine, and Triprolidine) were selected for their potential ability in treating lupus nephritis.

A drug/proton-antiporter, whose the molecular structure is still unknown, was previously evidenced at the blood-brain barrier (BBB) by functional experiments. The computational method could help in the identification of substrates of this solute carrier (SLC) transporter. Two pharmacophore models for substrates of this transporter using the FLAPpharm approach were developed. The trans-stimulation potency of 40 selected compounds for already known specific substrates ([3H]-clonidine) were determined and compared in the human brain endothelial cell line hCMEC/D3. Results. The two pharmacophore models obtained were used as templates to screen xenobiotic and endogenous compounds from four databases (e.g., Specs), and 45 hypothetical new candidates were tested to determine their substrate capacity. Psychoactive drugs such as antidepressants (e.g., imipramine, desipramine), antipsychotics/neuroleptics such as phenothiazine derivatives (chlorpromazine), sedatives anti-histamine-H1 drugs (promazine, promethazine, triprolidine, pheniramine), opiates/opioids (e.g., hydrocodone), trihexyphenidyl and sibutramine were correctly predicted as proton-antiporter substrates. The best performing pharmacophore model for the proton-antiporter substrates appeared as a good predictor of known substrates and allowed the identification of new substrate compounds. This model marks a new step in the characterization of this drug/proton-antiporter and will be of great use in uncovering its substrates and designing chemical entities with an improved influx capability to cross the BBB.

Current data on use of antihistamines during breastfeeding and risks to the breastfed infant are insufficient. The aim of this systematic review was to provide an overview of studies measuring the levels of antihistamines in human breast milk, estimating the exposure for breastfed infants and/or reporting possible adverse effects on the breastfed infant. An additional aim was to review the antihistamine product labels available in the European Union (EU) and the United States. We searched seven online databases and identified seven human lactation studies that included 25 mother-infant pairs covering cetirizine, clemastine, ebastine, epinastine, loratadine, terfenadine and triprolidine. In addition, one study investigated the impact of chlorpheniramine or promethazine on prolactin levels among 17 women, and one study investigated possible adverse drug reactions in 85 breastfed infants exposed to various antihistamines. The relative infant dose was below 5% for all antihistamines, ranging from 0.3% for terfenadine to 4.5% for clemastine. Most product labels of the 10 antihistamines with available information in both the EU and the United States reported lack of evidence and recommended to avoid use during breastfeeding. The knowledge gap on antihistamines and lactation is extensive, and further human studies are warranted to ensure optimal treatment of breastfeeding women with allergy.