Network pharmacology combined with Mendelian randomization analysis to identify the key targets of renin-angiotensin-aldosterone system inhibitors in the treatment of diabetic nephropathy.

Background: Diabetic Nephropathy (DN) is one of the microvascular complications of diabetes. The potential targets of renin-angiotensin-aldosterone system (RAAS) inhibitors for the treatment of DN need to be explored. Methods: The GSE96804 and GSE1009 datasets, 729 RAAS inhibitors-related targets and 6,039 DN-related genes were derived from the public database and overlapped with the differentially expressed genes (DN vs. normal) in GSE96804 to obtain the candidate targets. Next, key targets were screened via the Mendelian randomization analysis and expression analysis. The diagnostic nomogram was constructed and assessed in GSE96804. Additionally, enrichment analysis was conducted and a 'core active ingredient-key target-disease pathway' network was established. Finally, molecular docking was performed. Results: In total, 60 candidate targets were derived, in which CTSC and PDE5A were screened as the key targets and had a causal association with DN as the protective factors (P < 0.05, OR < 1). Further, a nomogram exhibited pretty prediction efficiency. It is indicated that Benadryl hydrochloride might play a role in the DN by affecting the pathways of 'cytokine cytokine receptor interaction', etc. targeting the CTSC. Moreover, PDE5A might be involved in 'ECM receptor interaction', etc. for the effect of NSAID, captopril, chlordiazepoxide on DN. Molecular docking analysis showed a good binding ability of benadryl hydrochloride and CTSC, NSAID and PDE5A. PTGS2, ITGA4, and ANPEP are causally associated with acute kidney injury. Conclusion: CTSC and PDE5A were identified as key targets for RAAS inhibitors in the treatment of DN, which might provide some clinical significance in helping to diagnose and treat DN. Among the targets of RAAS inhibitors, PTGS2, ITGA4 and ANPEP have a causal relationship with acute kidney injury, which is worthy of further clinical research.

Chitosan-coated alginate (CCA) nanoparticles for augmentation of topical antihistaminic activity of diphenhydramine: in-vitro optimization, skin histopathology and pharmacodynamic studies with in vitro/in vivo correlation.

OBJECTIVE: The aim of the present study was to formulate chitosan-coated alginate nanoparticles containing the drug diphenhydramine hydrochloride (DHH). SIGNIFICANCE: Diphenhydramine hydrochloride (DHH) is the prototype of H1-antihistaminic drugs. It is a lipophilic drug, that easily crosses the blood-brain barrier when taken orally causing decrements in alertness and performance. Multiple applications of topical drug products are required. Thus, drug incorporation in nanocarriers would increase the skin penetration powers increasing the drug efficacy. METHODS: Chitosan-coated alginate (CCA) nanoparticles were prepared via polyelectrolyte complex technique adopting 23 full factorial designs. Three factors, namely, alginate concentration, drug-to-alginate ratio and CaCl2 volume, each in two levels were studied. The prepared formulae were evaluated utilizing entrapment efficiency (EE), particle size (PS), polydispersity index (PDI), zeta potential (ZP) and in vitro release. The characterization process was then followed by optimization. RESULTS: At alginate conc. of 1%, drug to alginate ratio of 2:1 and CaCl2 volume of 4 mL, NP8 was chosen as a candidate formula. Histopathological examination on shaved rat dorsal skin disclosed the safety of NP8 with no signs of necrosis or even inflammation. The enhanced topical delivery of diphenhydramine hydrochloride enclosed in the developed nanoparticles was further proved by induction of allergic reaction using intradermal histamine injection. The results revealed the superior ability of NP8 to decrease the diameter of the formed wheal in comparison to the marketed DHH product. CONCLUSION: Thus, CCA nanoparticles are considered candidate nanocarriers for fortifying the topical antihistaminic activity of DHH.

Comparison of the preventive effect of colchicine versus diphenhydramine, prednisolone, and a combination therapy on intraperitoneal adhesion bands: an experimental study in rats.

BACKGROUND: Peritoneal adhesion formation is an inevitable consequence of abnormal repair of the peritoneum following different peritoneal injuries of intra-abdominal operations with the subsequent morbidity that they represent. Vast efforts have been made to elucidate the cause and prevent the development of abdominal adhesions. The aim of our study is to compare the capability of colchicine versus diphenhydramine (DPH) and methylprednisolone (MP), and also prednisolone in adhesion prevention. METHODS: Sixty-one male Wistar stock rats were divided into four groups. The first group attended as the control group. Groups 2, 3, and 4 received oral combination of MP + DPH solution (20 mg/kg), colchicine (0.02 mg/kg), and prednisolone (1 mg/ kg), respectively. Adhesion bands were induced by standardized abrasion of the peritoneum through a midline laparotomy. All rats were sacrificed on the 15th-day post medication administration and the subjects underwent an exploratory laparotomy. The presence of adhesions was evaluated with the modified using Nair's classification. RESULTS: The proportion of the control group with substantial adhesion bands (73.3%) was significantly higher than that of the MP + DPH (13.3%), colchicine (33.3%), and prednisolone (31.3%) groups. There were significant differences between the scores of the control and the MP + DPH, colchicine, and prednisolone groups (P = 0.001, 0.028, and 0.019, respectively). There was no statistically significant difference to favor colchicine against MP + DPH (P = 0.390) or MP + DPH against prednisolone (P = 0.394). CONCLUSIONS: Both colchicine and combination of DPH + MP prevented postoperative abdominal adhesions separately in our study. However, the lowest adhesion formation rate was observed in the DPH + MP group, even lower than the prednisolone group.

First approach to assess the effects of nanoplastics on the soil species Folsomia candida: A mixture design with bisphenol A and diphenhydramine.

The terrestrial environment is one of the main recipients of plastic waste. However, limited research has been performed on soil contamination by plastics and even less assessing the effects of nanoplastics (NPls). Behind the potential toxicity caused per se, NPls are recognized vectors of other environmental harmful contaminants. Therefore, the main aim of the present study is to understand whether the toxicity of an industrial chemical (bisphenol A - BPA) and a pharmaceutical (diphenhydramine - DPH) changes in the presence of polystyrene NPls to the terrestrial invertebrate Folsomia candida. Assessed endpoints encompassed organismal (reproduction, survival and behavior) and biochemical (neurotransmission and oxidative stress) levels. BPA or DPH, 28 d single exposures (1 to 2000 mg/kg), induce no effect on organisms' survival. In terms of reproduction, the calculated EC50 (concentration that causes 50% of the effect) and determined LOEC (lowest observed effect concentration) were higher than the environmental concentrations, showing that BPA or DPH single exposure may pose no threat to the terrestrial invertebrates. Survival and reproduction effects of BPA or DPH were independent on the presence of NPls. However, for avoidance behavior (48 h exposure), the effects of the tested mixtures (BPA + NPls and DPH + NPls) were dependent on the NPls concentration (at 0.015 mg/kg - interaction: no avoidance; at 600 mg/kg - no interaction: avoidance). Glutathione S-transferase activity increased after 28 d exposure to 100 mg/kg DPH + 0.015 mg/kg NPls (synergism). The increase of lipid peroxidation levels found after the exposure to 0.015 mg/kg NPls (a predicted environmental concentration) was not detected in the mixtures (antagonism). The results showed that the effects of the binary mixtures were dependent on the assessed endpoint and the tested concentrations. The findings of the present study show the ability of NPls to alter the effects of compounds with different natures and mechanisms of toxicity towards soil organisms, showing the importance of environmental risk assessment considering mixtures of contaminants.

Efficacy of Combination Haloperidol, Lorazepam, and Diphenhydramine vs. Combination Haloperidol and Lorazepam in the Treatment of Acute Agitation: A Multicenter Retrospective Cohort Study.

BACKGROUND: Antipsychotic and sedative combinations are commonly used for treating agitation in the emergency department despite limited evidence regarding their comparative safety and efficacy. OBJECTIVES: To compare the efficacy and safety of combination haloperidol, lorazepam, and diphenhydramine (B52) to combination haloperidol and lorazepam (52) in treating acute agitation. METHODS: This multicenter, retrospective cohort study included adult patients ≥ 18 years of age who received either B52 or 52 at a Banner Health facility between August 2017 and September 2020. Patients were excluded if they had a pre-existing movement disorder or were withdrawing from alcohol. The primary outcome was administration of additional agitation medication(s) within 2 h of B52 or 52. Secondary outcomes included incidence of extrapyramidal symptoms, length of stay, and additional safety measures. RESULTS: There was no difference in administration frequency of additional agitation medication(s) (B52: n = 28 [14%] vs. 52: n = 40 [20%]; p = 0.11). Patients who received 52 were more likely to require an antimuscarinic medication within 2 days (15 vs. 6 patients, p = 0.04). Of the patients who received an antimuscarinic medication, none had documented extrapyramidal symptoms. The 52 group had shorter length of stay (13.8 vs. 17 h; p = 0.03), lower incidence of hypotension (7 vs. 32 patients; p < 0.001), and oxygen desaturation (0 vs. 6 patients; p = 0.01), and fewer physical restraints (53 vs. 86 patients; p = 0.001) compared with the B52 group. CONCLUSIONS: Both the B52 and 52 combinations infrequently required repeat agitation medication; however, the B52 combination resulted in more oxygen desaturation, hypotension, physical restraint use, and longer length of stay.

Histamine as an Alert Signal in the Brain.

Sleep-wake behavior is a well-studied physiology in central histamine studies. Classical histamine H1 receptor antagonists, such as diphenhydramine and chlorpheniramine, promote sleep in animals and humans. Further, neuronal histamine release shows a clear circadian rhythm in parallel with wake behavior. However, the early stages of histamine-associated knockout mouse studies showed relatively small defects in normal sleep-wake control. To reassess the role of histamine in behavioral state control, this review summarizes the progress in sleep-wake studies of histamine-associated genetic mouse models and discusses the significance of histamine for characteristic aspects of wake behavior. Based on analysis of recent mouse models, we propose that neuronal histamine may serve as an alert signal in the brain, when high attention or a strong wake-drive is needed, such as during exploration, self-defense, learning, or to counteract hypersomnolent diseases. Enhanced histaminergic neurotransmission may help performance or sense of signals concerning internal or environmental dangers, like peripheral histamine from mast cells in response to allergic stimuli and inflammatory signals.

How do psychostimulants enter the human brain? Analysis of the role of the proton-organic cation antiporter.

BACKGROUND: Although psychostimulants apparently do cross the BBB, it is poorly understood how these hydrophilic and positively charged molecules can pass the blood-brain barrier (BBB). That may be mediated by a genetically still uncharacterized H+/OC antiporter with high activity at the BBB. METHODS: We studied the uptake of 16 psychostimulants and hallucinogens with hCMEC/D3 cells using the prototypic inhibitor imipramine (cis-inhibition), exchange transport with diphenhydramine and clonidine (trans-stimulation), proton dependency of the uptake, and we characterized the concentration-dependent uptake. RESULTS: Cell uptake of methylenedioxyamphetamines, amphetamines and dimethyltryptamine (DMT) were strongly inhibited (to about 10% of the controls) by imipramine and diphenhydramine, whereas uptake of cathine was only weakly inhibited and mescaline not significantly. Amphetamine, methylamphetamine, para-Methoxy-N-methylamphetamine (PMMA), Methylenedioxymethamphetamine (MDMA), phentermine and DMT exhibited the highest exchange after preloading with diphenhydramine with only 5.5%, 5.2%, 7.8%, 6%, 1.9%, 7.6% remaining in the cells. Less and no exchange were seen with cathine and mescaline, respectively. Dependence on intracellular pH was most pronounced with the methylendioxyamphetamines while uptake of cathine, DOI and cocaine were only moderately affected and mescaline not at all. CONCLUSION: Except for mescaline, all psychostimulants studied here were substrates of the H+/OC antiporter, implicating a strong need for a better characterization of this transport protein.

A randomized study of IV prochlorperazine plus diphenhydramine versus IV hydromorphone for migraine-associated symptoms: A post hoc analysis.

OBJECTIVE: We conducted a randomized trial among emergency department patients with migraine to determine the relative impact on migraine-associated symptoms of hydromorphone, an opioid, versus prochlorperazine, an antidopaminergic antiemetic. METHODS: This was a post hoc analysis of data from a double-blind study registered at http://clinicaltrials.gov (NCT02389829). Patients who met International Classification of Headache Disorders, 3rd edition criteria for migraine without aura or for probable migraine without aura were eligible for participation. Participants received either hydromorphone 1 mg IV or prochlorperazine 10 mg IV plus diphenhydramine 25 mg IV and could receive a second dose of the same medication 1 h later if needed. The outcomes were sustained relief of nausea, photophobia, and phonophobia. RESULTS: A total of 127 patients were enrolled, of whom 63 received prochlorperazine and 64 received hydromorphone. Of 49 patients in the prochlorperazine arm who reported nausea at baseline, 34 (69.4%) reported complete resolution without relapse versus 15/49 (30.6%) in the hydromorphone arm (absolute risk reduction [ARR] = 38.8%, 95% CI: 20.5%-57.0%, p < 0.001). Of 55 patients in the prochlorperazine arm who reported photophobia at baseline, 23 (41.8%) reported complete resolution without relapse versus 13/62 (20.9%) patients treated with hydromorphone (ARR = 20.8%, 95% CI: 4.3%-37.3%, p = 0.014). Of 56 patients in the prochlorperazine arm who reported phonophobia at baseline, 25 (44.6%) reported complete resolution without relapse versus 16/59 (27.1%) in the hydromorphone arm (ARR = 17.5%, 95% CI: 0.3%-34.8%, p = 0.049). For adverse events, three patients in the prochlorperazine arm reported anxiety or restlessness, and nine patients in the hydromorphone arm reported dizziness or weakness. CONCLUSIONS: Prochlorperazine plus diphenhydramine is more efficacious than hydromorphone for the treatment of migraine-associated symptoms.

Increased brain penetration of diphenhydramine and memantine in rats with adjuvant-induced arthritis.

Brain penetration of cationic drugs is an important determinant of their efficacy and side effects. However, the effects of alterations in the activity of uptake transporters in the brain under inflammatory conditions on the brain penetration of cationic drugs are not fully understood. The aim of this study was to examine changes in brain penetration of cationic drugs, including diphenhydramine (DPHM), memantine (MMT), and cimetidine (CMD), and changes in the expression of uptake transporters such as organic cation transporter (Oct) in brain microvascular endothelial cells (BMECs) under inflammatory conditions. To clarify the effects of inflammation on the brain penetration of DPHM, MMT, and CMD, we performed brain microdialysis studies in a rat model of adjuvant-induced arthritis (AA). Further, differences in transporter mRNA expression levels between BMECs from control and AA rats were evaluated. Brain microdialysis showed that the unbound brain-to-plasma partition coefficient (Kp,uu,brain) for DPHM and MMT was significantly lower in AA rats compared with control rats. OCT mRNA levels were increased and proton-coupled organic cation (H+/OC) antiporter mRNA levels were decreased in AA rats compared with control rats. Taken together, our findings suggest that inflammation decreases the brain penetration of H+/OC antiporter substrates such as DPHM and MMT.

Diphenhydramine and levofloxacin combination therapy against antimicrobial resistance in respiratory tract infections.

Background: Antibiotics are in use since decades to treat various infections caused by Gram-positive and Gram-negative bacteria such as Staphylococcus aureus and Pseudomonas aeruginosa. Diphenhydramine, an H1 receptor blocker possesses a weak antibiotic action but when combined with other antibiotics may potentiate their antibacterial activity. Materials & methods: This study investigated in vitro antibacterial activity of diphenhydramine when used alone and in combination with levofloxacin against methicillin-resistant S. aureus and P. aeruginosa. Results: The combined antibacterial effect of the drugs against bacteria showed a fractional inhibitory concentration index of ≤0.5, in other words, synergism. No cytotoxicity was observed as percentage cell viability was >50%. Conclusion: The combination of diphenhydramine and levofloxacin exerted antibacterial activity, and was not found to be cytotoxic when given in combination against P. aeruginosa and S. aureus.

The short third intracellular loop and cytoplasmic tail of bitter taste receptors provide functionally relevant GRK phosphorylation sites in TAS2R14.

For most G protein-coupled receptors, the third intracellular loop (IL3) and carboxy-terminal tail (CT) are sites for G protein-coupled receptor kinase (GRK)-mediated phosphorylation, leading to ß-arrestin binding and agonist-specific desensitization. These regions of bitter taste receptors (TAS2Rs) are extremely short compared with the superfamily, and their function in desensitization is unknown. TAS2R14 expressed on human airway smooth muscle cells relax the cell, suggesting a novel target for bronchodilators. To assess IL3 and CT in agonist-promoted TAS2R14 desensitization (tachyphylaxis), we generated fusion proteins of both the WT sequence and Ala substituted for Ser/Thr in the IL3 and CT sequences. In vitro, activated GRK2 phosphorylated WT IL3 and WT CT proteins but not Ala-substituted forms. TAS2R14s with mutations in IL3 (IL-5A), CT (CT-5A), and in both regions (IL/CT-10A) were expressed in human embryonic kidney 293T cells. IL/CT-10A and CT-5A failed to undergo desensitization of the intracellular calcium response compared with WT, indicating that functional desensitization by GRK phosphorylation is at residues in the CT. Desensitization of TAS2R14 was blocked by GRK2 knockdown in human airway smooth muscle cells. Receptor:ß-arrestin binding was absent in IL/CT-10A and CT-5A and reduced in IL-5A, indicating a role for IL3 phosphorylation in the ß-arrestin interaction for this function. Agonist-promoted internalization of IL-5A and CT-5A receptors was impaired, and they failed to colocalize with early endosomes. Thus, agonist-promoted functional desensitization of TAS2R14 occurs by GRK phosphorylation of CT residues and ß-arrestin binding. However, ß-arrestin function in the internalization and trafficking of the receptor also requires GRK phosphorylation of IL3 residues.

Effectiveness of Standard Combination Therapy in Pediatric Migraine.

BACKGROUND: A combination of parenteral medications (often referred to as standard combination therapy) is frequently used in the treatment of acute migraine in the pediatric emergency department (PED). The primary aim of this study was to evaluate the two-hour, 24-hour, and seven-day impact of one such regimen on pain in children who present to the PED. Standard combination therapy for purposes of our study is defined as a bolus of intravenous saline, and a combination of intravenous ketorolac, prochlorperazine, and diphenhydramine. METHODS: This prospective observational study included 120 children between the ages seven and 18 years who presented to the PED with migraine, whose parents could read and understand the consent form in English, and who were treated with standard combination therapy. The primary outcome measure for this study was the change in severity of pain as noted by the child using the Faces Pain Scale-Revised. We analyzed normally distributed continuous variables by mean and standard deviation, whereas non-normally distributed continuous variables are reported by median and interquartile range. RESULTS: Nonparametric Friedman testing on the entire cohort (n = 120) noted that there was a statistically significant change in the Faces pain scale from before administration of standard combination therapy to the two-hour, 24-hour, and one-week time point with a reduction in pain score of 87.5%, 100%, and 50%, respectively, at the three time points. CONCLUSIONS: This study noted moderate relief of pain after administration of standard combination therapy, which persisted at one-week after administration.

Diphenhydramine may be a preventive medicine against cisplatin-induced kidney toxicity.

Cisplatin is widely used as an anti-tumor drug for the treatment of solid tumors. Unfortunately, it causes kidney toxicity as a critical side effect, limiting its use, given that no preventive drug against cisplatin-induced kidney toxicity is currently available. Here, based on a repositioning analysis of the Food and Drug Administration Adverse Events Reporting System, we found that a previously developed drug, diphenhydramine, may provide a novel treatment for cisplatin-induced kidney toxicity. To confirm this, the actual efficacy of diphenhydramine was evaluated in in vitro and in vivo experiments. Diphenhydramine inhibited cisplatin-induced cell death in kidney proximal tubular cells. Mice administered cisplatin developed kidney injury with significant dysfunction (mean plasma creatinine: 0.43 vs 0.15 mg/dl) and showed augmented oxidative stress, increased apoptosis, elevated inflammatory cytokines, and MAPKs activation. However, most of these symptoms were suppressed by treatment with diphenhydramine. Furthermore, the concentration of cisplatin in the kidney was significantly attenuated in diphenhydramine-treated mice (mean platinum content: 70.0 vs 53.4 µg/g dry kidney weight). Importantly, diphenhydramine did not influence or interfere with the anti-tumor effect of cisplatin in any of the in vitro or in vivo experiments. In a selected cohort of 98 1:1 matched patients from a retrospective database of 1467 patients showed that patients with malignant cancer who had used diphenhydramine before cisplatin treatment exhibited significantly less acute kidney injury compared to ones who did not (6.1 % vs 22.4 %, respectively). Thus, diphenhydramine demonstrated efficacy as a novel preventive medicine against cisplatin-induced kidney toxicity.

Activation of multiple receptors stimulates extracellular vesicle release from trophoblast cells.

Reports of the stimulated release of extracellular vesicles (EVs) are few, and the mechanisms incompletely understood. To our knowledge, the possibility that the activation of any one of the multitudes of G-protein-coupled receptors (GPCRs) expressed by a single cell-type might increase EV release has not been explored. Recently, we identified the expression of cholecystokinin (CCK), gastrin, gastrin/cholecystokinin types A and/or B receptors (CCKAR and/or -BR), and the bitter taste receptor, TAS2R14 in the human and mouse placenta. specifically, trophoblast. These GPCR(s) were also expressed in four different human trophoblast cell lines. The current objective was to employ two of these cell lines-JAR choriocarcinoma cells and HTR-8/SVneo cells derived from first-trimester human villous trophoblast-to investigate whether CCK, TAS2R14 agonists, and other GPCR ligands would each augment EV release. EVs were isolated from the cell-culture medium by filtration and ultracentrifugation. The preparations were enriched in small EVs (<200 nm) as determined by syntenin western blot before and after sucrose gradient purification, phycoerythrin (PE)-ADAM10 antibody labeling, and electron microscopy. Activation of TAS2R14, CCKBR, cholinergic muscarinic 1 & 3, and angiotensin II receptors, each increased EV release by 4.91-, 2.79-, 1.87-, and 3.11-fold, respectively (all p < .05 versus vehicle controls), without significantly changing EV diameter. A progressive increase of EV concentration in conditioned medium was observed over 24 hr consistent with the release of preformed EVs and de novo biogenesis. Compared to receptor-mediated stimulation, EV release by the calcium ionophore, A23187, was less robust (1.63-fold, p = .08). Diphenhydramine, a TAS2R14 agonist, enhanced EV release in JAR cells at a concentration 10-fold below that required to increase intracellular calcium. CCK activation of HTR-8/SVneo cells, which did not raise intracellular calcium, increased EV release by 2.06-fold (p < .05). Taken together, these results suggested that other signaling pathways may underlie receptor-stimulated EV release besides, or in addition to, calcium. To our knowledge, the finding that the activation of multiple GPCRs can stimulate EV release from a single cell-type is unprecedented and engenders a novel thesis that each receptor may orchestrate intercellular communication through the release of EVs containing a subset of unique cargo, thus mobilizing a specific integrated physiological response by a network of neighboring and distant cells.

A new sponge-type hydrogel based on hyaluronic acid and poly(methylvinylether-alt-maleic acid) as a 3D platform for tumor cell growth.

A new sponge-type hydrogel was obtained by cross-linking hyaluronic acid (HA) and poly(methylvinylether-alt-maleic acid) P(MVE-alt-MA) through a solvent-free thermal method. The sponge-type hydrogel was characterized and checked as a support for cell growth. The influence of concentration and weight ratio of polymers on the morphology and hydrogel stability was investigated. The total polymers concentration of 3% (w/w) and the weight ratio of 1:1 were optimal for the synthesis of a stable hydrogel (HA3P50) and to promote cell proliferation. The swelling measurements revealed a high-water absorption capacity of the hydrogel in basic medium. Diphenhydramine (DPH), lidocaine (Lid) and propranolol (Prop) were loaded within the hydrogel as a model drugs to investigate the ability of drug transport and release. In vitro studies revealed that HA3P50 hydrogel promoted the adhesion and proliferation of human hepatocellular carcinoma cell line HepG2, providing a good support for 3D cell culture to obtain surrogate tumor scaffold suitable for preclinical anti-cancer drug screening.

Voltage-dependent modulation of TRPA1 currents by diphenhydramine.

Diphenhydramine (DPH) has been broadly used to treat allergy. When used as a topical medicine, DPH temporarily relieves itching and pain. Although transient receptor potential type A1 (TRPA1) channel is known to play roles in both acute and chronic itch and pain, whether DPH affects the activities of TRPA1 remains unclear. Using whole-cell patch clamp recordings, we demonstrated that DPH modulates the voltage-dependence of TRPA1. When co-applied with a TRPA1 agonist, DPH significantly enhanced the inward currents while suppressing the outward currents of TRPA1, converting the channel from outwardly rectifying to inwardly rectifying. This effect of DPH occurred no matter TRPA1 was activated by an electrophilic or non-electrophilic agonist and for both mouse and human TRPA1. The modulation of TRPA1 by DPH was maintained in the L906C mutant, which by itself also causes inward rectification of TRPA1, indicating that additional acting sites are present for the modulation of TRPA1 currents by DPH. Our recordings also revealed that DPH partially blocked capsaicin evoked TRPV1 currents. These data suggest that DPH may exert its therapeutic effects on itch and pain, through modulation of TRPA1 in a voltage-dependent fashion.

Future Oncotargets: Targeting Overexpressed Conserved Protein Targets in Androgen Independent Prostate Cancer Cell Lines.

BACKGROUND: Targeting evolutionarily conserved proteins in malignant cells and the adapter proteins involved in signalling that generates from such proteins may play a cardinal role in the selection of anti-cancer drugs. Drugs targeting these proteins could be of importance in developing anti-cancer drugs. OBJECTIVES: We inferred that drugs like loperamide and promethazine that act as antagonists of proteins conserved in cancer cells like voltage-gated Calcium channels (Cav), Calmodulin (CaM) and drug efflux (ABCB1) pump may have the potential to be re-purposed as an anti-cancer agent in Prostate Cancer (PCa). METHODS: Growth and cytotoxic assays were performed by selecting loperamide and promethazine to target Cav, CaM and drug efflux (ABCB1) pumps to elucidate their effects on androgen-independent PC3 and DU145 PCa cell lines. RESULT: We show that loperamide and promethazine in doses of 80-100µg/ml exert oncocidal effects when tested in DU145 and PC3 cell lines. Diphenhydramine, which shares its targets with promethazine, except the CaM, failed to exhibit oncocidal effects. CONCLUSION: Anti-cancer effects can be of significance if structural analogues of loperamide and promethazine that specifically target Cav, CaM and ABCB1 drug efflux pumps can be synthesized, or these two drugs could be re-purposed after human trials in PCa.

Percutaneous Absorption of Lorazepam, Diphenhydramine Hydrochloride, and Haloperidol from ABH Gel.

The objective of this project was to study the percutaneous absorption of lorazepam, diphenhydramine hydrochloride, and haloperidol from a topical Pluronic lecithin organogel, also known as ABH gel, across the porcine ear skin and verify its suitability for topical application. ABH gel was prepared using lecithin in isopropyl palmitate solution (1:1) as an oil phase and 20% w/v Poloxamer 407 solution as an aqueous phase. The gel was characterized for pH, viscosity, drug content, and thermal behavior. A robust high-performance liquid chromatography method was developed and validated for simultaneous analysis of lorazepam, diphenhydramine hydrochloride, and haloperidol. The percutaneous absorption of lorazepam, diphenhydramine hydrochloride, and haloperidol from ABH gel was carried out using Franz cells across the Strat-M membrane and pig ear skin. The pH of ABH gel was found to be 5.66 ± 0.13. The retention time of diphenhydramine hydrochloride, haloperidol, and lorazepam was found to be 5.2 minutes, 7.8 minutes, and 18.9 minutes, respectively. The ABH gel was found to be stable for up to 30 days. Theoretical steady state plasma concentrations (CSS) of diphenhydramine hydrochloride, haloperidol, and lorazepam calculated from flux values were found to be 1.6 ng/mL, 0.13 ng/mL, and 2.30 ng/mL, respectively. The theoretical CSS of diphenhydramine hydrochloride, haloperidol, and lorazepam were much lower than required therapeutic concentrations for antiemetic activity to relieve chemotherapy-induced nausea and vomiting. From the percutaneous absorption data, it was evident that ABH gel failed to achieve required systemic levels of lorazepam, diphenhydramine hydrochloride, and haloperidol following topical application.

Bitterness-Suppressing Effect of Umami Dipeptides and Their Constituent Amino Acids on Diphenhydramine: Evaluation by Gustatory Sensation and Taste Sensor Testing.

Diphenhydramine, a sedating antihistamine, is an agonist of human bitter taste receptor 14 (hTAS2R14). Diphenhydramine hydrochloride (DPH) was used as a model bitter medicine to evaluate whether the umami dipeptides (Glu-Glu and Asp-Asp) and their constituent amino acids (Glu, Asp) could suppress its bitterness intensity, as measured by human gustatory sensation testing and using the artificial taste sensor. Various concentrated (0.001-5.0 mM) Glu-Glu, Asp-Asp, Glu and Asp significantly suppressed the taste sensor output of 0.5 mM DPH solution in a dose-dependent manner. The effect of umami dipeptides and their constituent amino acids was tending to be ranked as follows, Asp-Asp > Glu-Glu >> Gly-Gly, and Asp > Glu >> Gly (control) respectively. Whereas human bitterness intensity of 0.5 mM DPH solution with various concentrated (0.5, 1.0, 1.5 mM) Glu-Glu, Asp-Asp, Glu and Asp all significantly reduced bitterness intensity of 0.5 mM DPH solution even though no statistical difference was observed among four substances. The taste sensor outputs and the human gustatory sensation test results showed a significant correlation. A surface plasmon resonance study using hTAS2R14 protein and these substances suggested that the affinity of Glu-Glu, Asp-Asp, Glu and Asp for hTAS2R14 protein was greater than that of Gly-Gly or Gly. The results of docking-simulation studies involving DPH, Glu-Glu and Asp-Asp with hTAS2R14, suggested that DPH is able to bind to a space near the binding position of Glu-Glu and Asp-Asp. In conclusion, the umami dipeptides Glu-Glu and Asp-Asp, and their constituent amino acids, can all efficiently suppress the bitterness of DPH.

Diphenhydramine increases the therapeutic window for platinum drugs by simultaneously sensitizing tumor cells and protecting normal cells.

Platinum-based compounds remain a well-established chemotherapy for cancer treatment despite their adverse effects which substantially restrict the therapeutic windows of the drugs. Both the cell type-specific toxicity and the clinical responsiveness of tumors have been associated with mechanisms that alter drug entry and export. We sought to identify pharmacological agents that promote cisplatin (CP) efficacy by augmenting the levels of drug-induced DNA lesions in malignant cells and simultaneously protecting normal tissues from accumulating such damage and from functional loss. Formation and persistence of platination products in the DNA of individual nuclei were measured in drug-exposed cell lines, in primary human tumor cells and in tissue sections using an immunocytochemical method. Using a mouse model of CP-induced toxicity, the antihistaminic drug diphenhydramine (DIPH) and two methylated derivatives decreased DNA platination in normal tissues and also ameliorated nephrotoxicity, ototoxicity, and neurotoxicity. In addition, DIPH sensitized multiple cancer cell types, particularly ovarian cancer cells, to CP by increasing intracellular uptake, DNA platination, and/or apoptosis in cell lines and in patient-derived primary tumor cells. Mechanistically, DIPH diminished transport capacity of CP efflux pumps MRP2, MRP3, and MRP5 particularly in its C2+C6 bimethylated form. Overall, we demonstrate that DIPH reduces side effects of platinum-based chemotherapy and simultaneously inhibits key mechanisms of platinum resistance. We propose that measuring DNA platination after ex vivo exposure may predict the responsiveness of individual tumors to DIPH-like modulators.