Regulatory roles of dopamine D2 receptor in milk protein production and apoptosis in mammary epithelial cells.

Dopamine D2 receptors (D2Rs) play crucial roles in regulating diverse physiological functions of the central nervous system and peripheral organs. D2Rs are also expressed in mammary glands. However, which cell types express D2Rs and whether they are involved in milk production remains unclear. The present findings revealed that D2Rs are expressed in the apical regions of the lateral membranes of mammary epithelial cells (MECs) in lactating mice. We also investigated the effects of the D2R agonist bromocriptine and/or antagonist domperidone on intracellular cAMP levels, milk protein production, and apoptosis in a lactation culture model of MECs that produce major milk components like lactating MECs in vivo. We found that bromocriptine decreased intracellular cAMP levels, whereas domperidone dose-dependently neutralized this effect. Bromocriptine also inhibited casein and lactoferrin production and suppressed activities of STAT5 and glucocorticoid receptors (GRs). Domperidone neutralized the inhibition of casein production as well as STAT5 and GR inactivation induced by bromocriptine. Furthermore, D2R activation by bromocriptine induced apoptosis and inactivated ERK, a signaling molecule responsible for promoting cell proliferation and survival. Domperidone attenuated ERK inactivation and apoptosis induced by bromocriptine. These findings suggest that D2Rs play regulatory roles in milk protein production and apoptosis in MECs.

Effect of temperature and spawning agents on wild female asp (Leuciscus aspius) reproductive efficiency under controlled conditions.

Artificial reproduction is a bottleneck to produce stocking material for many species of freshwater fish. One of these species is the asp, Leuciscus aspius. Research in the field of artificial reproduction of this species is very scarce and often incomplete. There are no breeding protocols specifying optimal environmental conditions and hormonal stimulation for many species of rheophilic cyprinids, including asp. Since the number of natural asp populations is constantly decreasing, it is important to support natural stocks by restocking with high quality stocking material. For this reason, optimized protocols are needed to breed this species under controlled conditions to produce stocking material with high biodiversity and good health. Such an approach will make it possible to maintain the population of natural asp at a constant level. The aim of this study was to develop the protocol of asp artificial reproduction using optimized thermal conditions and appropriate hormonal stimulation. In experiment I, the influence of constant temperature (10.0, 12.0 and 14.0 °C) on the effectiveness of artificial reproduction of asp. In experiment II, the effectiveness of asp reproduction was checked after the application of spawning agents: Ovopel, Ovaprim or a combination of these two agents The obtained results indicate that for the final maturation of oocytes (FOM) and artificial reproduction of asp in controlled conditions, water temperatures of 10-12 °C are the most useful. Under these thermal conditions, the highest percentages of female's ovulation and embryo survival, as well as the percentage of hatching, were obtained. Hormone injections are necessary to perform final oocyte maturation (FOM) in female asp in captivity. All spawning agents used were especially useful for artificial reproduction of asp, however, the best values of the studied indices, such as ovulation rate and embryo survival, were obtained after the application of Ovaprim or the combination of Ovopel and Ovaprim in water temperature at a range of 10-12 °C. It was found that the pH of ovarian fluid may be a preliminary indicator of the biological quality of eggs in asps. The optimal pH value is 8.0-8.4. At pH below 7.4, no viable embryos were observed.

Analysis of a Pharmacy Developed, Outpatient Lactation Consultant Initiated Domperidone Programme.

BACKGROUND: Domperidone is a commonly prescribed galactagogue used off-label for lactation insufficiency. Prescriber unfamiliarity or safety concerns can lead to therapeutic delay and potential early breastfeeding discontinuation. To facilitate access, the study site pharmacy department developed a Structured Administration and Supply Arrangement (SASA) for International Board-Certified Lactation Consultants (IBCLC) to screen and initiate domperidone using a checklist. MATERIAL: To validate a domperidone screening tool via analysis of its use and compliance, together with a staff satisfaction survey. METHODS: Records were extracted from the REDCap® database for women with documented domperidone supply between 06/05/2022 and 27/01/2023 and reviewed with medical records. A staff survey was distributed assessing compliance and attitudes towards the SASA. RESULTS: Records of supply revealed that 34% (17/50) of patients were referred to a physician, revealing a discrepancy between database documentation and checklists, as no referrals were documented. Overall staff satisfaction with the SASA was rated 4.6 out of 5. 77.7% (7/9) felt confident counselling and supplying domperidone with the SASA in place. 88.9% (8/9) felt confident using the checklist to identify the appropriateness of therapy and referral to a physician. CONCLUSIONS: The system in place allows the IBCLCs to initiate and supply domperidone in a timely manner to breastfeeding mothers with lactation insufficiency. The support tools, including domperidone SASA, REDCap® documentation database and the checklist domperidone as a Galactagogue Checklist, can be greatly appreciated by the LCs. Continued discussion with IBCLCs to refine and improve the SASA and associated education package will result in more consistent compliance.

The use of prescription medications and non-prescription medications during lactation in a prospective Canadian cohort study.

BACKGROUND: A lack of safety data on postpartum medication use presents a potential barrier to breastfeeding and may result in infant exposure to medications in breastmilk. The type and extent of medication use by lactating women requires investigation. METHODS: Data were collected from the CHILD Cohort Study which enrolled pregnant women across Canada between 2008 and 2012. Participants completed questionnaires regarding medications and non-prescription medications used and breastfeeding status at 3, 6 and 12 months postpartum. Medications, along with self-reported reasons for medication use, were categorized by ontologies [hierarchical controlled vocabulary] as part of a large-scale curation effort to enable more robust investigations of reasons for medication use. RESULTS: A total of 3542 mother-infant dyads were recruited to the CHILD study. Breastfeeding rates were 87.4%, 75.3%, 45.5% at 3, 6 and 12 months respectively. About 40% of women who were breastfeeding at 3 months used at least one prescription medication during the first three months postpartum; this proportion decreased over time to 29.5% % at 6 months and 32.8% at 12 months. The most commonly used prescription medication by breastfeeding women was domperidone at 3 months (9.0%, n = 229/2540) and 6 months (5.6%, n = 109/1948), and norethisterone at 12 months (4.1%, n = 48/1180). The vast majority of domperidone use by breastfeeding women (97.3%) was for lactation purposes which is off-label (signifying unapproved use of an approved medication). Non-prescription medications were more often used among breastfeeding than non-breastfeeding women (67.6% versus 48.9% at 3 months, p < 0.0001), The most commonly used non-prescription medications were multivitamins and Vitamin D at 3, 6 and 12 months postpartum. CONCLUSIONS: In Canada, medication use is common postpartum; 40% of breastfeeding women use prescription medications in the first 3 months postpartum. A diverse range of medications were used, with many women taking more than one prescription and non-prescription medicines. The most commonly used prescription medication by breastfeeding women were domperidone for off-label lactation support, signalling a need for more data on the efficacy of domperidone for this indication. This data should inform research priorities and communication strategies developed to optimize care during lactation.

Feasibility study to assess lesion repair in relapsing-remitting multiple sclerosis: A randomized controlled pilot clinical trial of domperidone add-on treatment.

BACKGROUND: Identification of therapies to promote repair in multiple sclerosis is challenged by the lack of an accepted trial model and associated outcome measures. The goal of this study was to determine the feasibility of a new trial model that enrolls disease modifying therapy (DMT)-treated relapsing-remitting multiple sclerosis (RRMS) participants who have enhancing lesions on clinically indicated brain MRI, and to explore estimates of lesion repair using MRI. METHODS: This was a single site randomized controlled clinical trial. Recruitment took place between November 2015 and January 2019, with final follow-up in February 2019. DMT-treated RRMS participants aged 18-60 years with at least one gadolinium-enhancing lesion on clinically indicated brain MRI were included. Participants were randomized 2:1 to oral domperidone add-on 10-mg three times daily for 16 weeks or no add-on treatment (control). The primary outcomes were feasibility of the model pre-defined as recruitment of 24 participants within 36 months with a 79 % completion rate, and MRI outcomes of lesion repair measured at 16 and 32 weeks using texture analysis, magnetization transfer imaging (MTI), and diffusion tensor imaging (DTI). The impact of domperidone on serum prolactin at 6 and 16 weeks was also evaluated. RESULTS: Of 237 RRMS participants screened, 17 (14 women) were randomized: 12 to domperidone add-on and 5 to control. All completed the study. Median (range) age was 38.9 (26.7-55.9) years; EDSS was 1.5 (1.0-3.5); and disease duration was 12.9 (2.9-23.3) years. Both groups showed improvement in MRI texture and diffusion fractional anisotropy (FA) at 32 weeks, and the domperidone group demonstrated additional recovery at 16 weeks in both texture and FA. There was no significant group difference in any MRI outcome. Of the 12 domperidone participants, 7 had ≥4x higher serum prolactin than normal. There were no serious adverse events. CONCLUSION: The recruitment target was not met and therefore the trial model was not feasible despite a full completion rate. The imaging techniques performed well, especially MRI texture analysis, suggesting the sample size being sufficient for estimating lesion repair. The main challenge of this trial model may be recruiting gadolinium-enhancing lesions in DMT-treated RRMS participants. Prolactin is safe and may hold promise as a remyelination therapy. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02493049.

Longitudinal trends in domperidone dispensing to mothers of very preterm infants and its association with breast milk feeding at infant discharge: a retrospective study.

OBJECTIVE: This study aims: (a) to evaluate patterns of domperidone dispensing to mothers of very preterm (<32 weeks gestation) infants born before and after 2014 when international recommendations were made to limit its use and (b) to examine characteristics associated with domperidone dispensing and impacts on breast milk feeding rates at infant hospital discharge. DESIGN: Retrospective audit using linked electronic medical records and hospital pharmacy records. SETTING: Tertiary-referral neonatal intensive care unit at the Women's and Children's Hospital in South Australia. PATIENTS: Mothers of preterm infants admitted to neonatal intensive care from January 2004 to December 2018. MAIN OUTCOME MEASURES: Rate of domperidone dispensing compared pre-2014 and post-2014 recommendations using interrupted time series analyses, and breast milk feeding rates at infant discharge based on domperidone treatment status, adjusted for other factors known to influence breast milk production. RESULTS: Overall, domperidone was dispensed to 691 (41%) of 1688 mothers. Prior to 2014 recommendations, the proportion of women dispensed domperidone was stable. Following the recommendations, there was a significant reduction in trend (-2.55% per half year, 95% CI -4.57% to -0.53%;), reflecting less domperidone dispensing.Breast milk feeding rates at discharge remained consistently lower in infants of women dispensed domperidone than those who were not (adjusted OR 0.58, 95% CI 0.45 to 0.75). CONCLUSION: Domperidone dispensing in mothers of hospitalised very preterm infants has declined over time following international regulatory warnings. Breast milk feeding rates remain lower in mothers prescribed domperidone, suggesting further research is needed to optimise lactation support for mothers of very preterm infants.

Prokinetics for the treatment of functional dyspepsia: an updated systematic review and network meta-analysis.

BACKGROUND: Since the previous network meta-analysis assessing the efficacy of prokinetics for functional dyspepsia (FD), there have been a number of new studies and cinitapride is a new prokinetic agent for FD. This updated meta-analysis aimed to explore the efficacy and safety of prokinetics for FD. METHODS: An updated study search in Pubmed, EMBASE, Cochrane Library and Web of Science was conducted in literatures published from July 2015 to March 2023. Randomized controlled trials investigating the use of prokinetics in adult FD patients were included. The primary outcome was the total efficacy rate and the secondary outcome was adverse events. A Bayesian network meta-analysis was performed using R software. RESULTS: A total of 28 studies were included. Network meta-analysis showed that metoclopramide had a higher total efficacy rate than mosapride (OR: 3.53, 95%CI: 1.70-7.47), domperidone (OR: 2.29, 95%CI: 1.16-4.63), itopride(OR: 2.77, 95%CI: 1.41-5.59), acotiamide(OR: 2.63, OR: 1.33-5.36), and placebo(OR: 5.68, 95%CI: 2.98-11.10), however similar to cinitapride (OR: 1.62, 95%CI: 0.75-3.53). Cinitapride had a higher total efficacy rate than mosapride (OR: 2.18, 95%CI: 1.16-4.14) and placebo (OR: 3.52, 95%CI: 2.01-6.24). Cinitapride had lower risk of total adverse events than domperidone. There was no difference in the risk of drug-related adverse events between the prokinetics. CONCLUSIONS: Metoclopramide and cinitapride may have a better efficacy than other prokinetics in the treatment of FD, and cinitapride may have a lower risk of total adverse events. Further studies using uniform definitions or validated tools to measure the total efficacy rate are needed.

Treatment of functional dyspepsia in Chinese adult patients with domperidone: A multicenter, randomized, double-blind, placebo-controlled pilot study.

OBJECTIVE: This pilot study aimed to evaluate the efficacy and safety of domperidone for the treatment of Chinese patients with functional dyspepsia (FD) who were diagnosed according to the Rome IV criteria and to identify the FD subtypes that potentially responded better to domperidone. METHODS: This multicenter prospective study was conducted in China from August 2018 to July 2020, consisting of a 1-week screening phase and a 2-week double-blind treatment phase. Participants were randomized to receive domperidone 10 mg or matching placebo tablets thrice daily for 14 days. The primary end-point was the overall treatment effect (OTE) response rate after 2-week therapy. RESULTS: Altogether 160 patients were included, with 80 patients in each group. The OTE response rate after 2-week therapy was significantly higher for domperidone compared with placebo (60.7% vs 46.0%; relative risk [RR] 1.318, 95% confidence interval [CI] 0.972-1.787). Moreover, the OTE response rate after 2-week domperidone or placebo treatment was 60.3% versus 54.9% for postprandial distress syndrome (PDS) (RR 1.098, 95% CI 0.750-1.607) and 60.6% versus 35.2% for overlapping PDS-epigastric pain syndrome (EPS) (RR 1.722, 95% CI 0.995-2.980). Adverse events were reported by seven patients in the domperidone group and 12 patients in the placebo group. None of the adverse events in the domperidone group were serious. CONCLUSION: Domperidone showed a positive pattern regarding OTE response rates after 2-week therapy compared to placebo in patients with FD, as well as in subtypes of PDS and overlapping PDS-EPS. No new safety issue was observed.

A blinded, randomized and controlled multicenter clinical trial to assess the efficacy and safety of Leisguard® as an immunotherapeutic treatment for healthy Leishmania infantum-seropositive dogs.

BACKGROUND: Domperidone (Leisguard®) is an immunomodulatory drug used as a preventive measure in healthy dogs. However, no studies have been published in healthy Leishmania infantum-seropositive dogs. The aim of this study was to evaluate the clinical efficacy and safety of domperidone as immunotherapy in Leishmania-seropositive healthy dogs. METHODS: Sixty-seven dogs were treated with domperidone at 0.5 mg/kg and 44 dogs received placebo, once daily for 4 consecutive weeks. Monthly treatments were repeated every 4 months until the end of the 1-year follow-up period. Veterinary examinations were performed on days 0, 30, 120, 150, 240, 270 and 360. Samples of blood and urine were collected on days 0, 120, 240 and 360 for routine laboratory tests and quantitative in-house ELISA for the detection of L. infantum-specific antibodies. Furthermore, Leishmania real-time PCR and IFN-γ ELISA were performed at day 0 and the end of the study. Dogs that developed disease were withdrawn from the study and classified as sick dogs. Adverse drug reactions were reported. RESULTS: Thirty dogs developed disease during the follow-up period: 13/67 (19.4%) in the group treated with domperidone and 17/44 (38.6%) in the placebo-treated group (P = 0.03). Low-seropositive dogs treated with domperidone (4/40, 9.1%) were significantly less likely to develop disease compared to low-seropositive dogs treated with placebo (7/24, 29.2%; P = 0.04), while no differences were found between domperidone (9/23, 39.1%) and placebo (10/20, 50%) in medium- to high-seropositive dogs. At the end of the study, a higher proportion of Leishmania PCR-positive dogs was observed in the placebo-treated group (16/33, 48.5%) compared to the domperidone group (13/51, 25.5%; P = 0.04). Furthermore, low-seropositive dogs treated with domperidone with an increase of IFN-γ concentration presented a higher increase than those treated with placebo at the end of the study. Four dogs treated with domperidone presented self-limiting diarrhea. CONCLUSIONS: Healthy dogs with low L. infantum antibody levels treated with domperidone were less likely to develop disease compared to placebo-treated dogs. Furthermore, domperidone presented a good safety profile.

A randomized, double-blind study on the efficacy of oral domperidone versus placebo for reducing SARS-CoV-2 viral load in mild-to-moderate COVID-19 patients in primary health care.

INTRODUCTION: The clinical effect of domperidone against COVID-19 has been investigated in a double-blind phase III clinical trial (EudraCT number 2021-001228-17). Domperidone has shown in vitro antiviral activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and potential immudolatory properties through the stimulation of prolactin secretion. PATIENTS AND METHODS: The efficacy of oral domperidone plus standard of care (SOC; n = 87) versus placebo plus SOC (n = 86) was evaluated in a 28-day randomized double-blind multicentre study in primary health care centres. A total of 173 outpatients with mild-to-moderate COVID-19 were included. Three daily doses of 10 mg (30 mg/day) of domperidone or placebo were administered for 7 days. Reduction of viral load on day 4 was the primary efficay endpoint. It was estimated in saliva samples by reverse transcription-quantitative polymerase chain reaction (RT-qPCR), as the cycle thresholds detected ORF1ab, N Protein and S Protein genes. RESULTS: A significant reduction in the viral load was observed (p < 0.001) from baseline to days 4, 7 and 14 of the three genes studied with non-significant differences between domperidone and placebo groups. Twenty-three patients (13.3%) experienced adverse events, 14 patients in the domperidone group (16.1%) and 9 patients in the placebo group (10.5%). No patients needed to be hospitalized. CONCLUSION: Results do not prove the use of domperidone as antiviral in patients with COVID-19.

A 28-day double-blind clinical trial was performed to investigate the antiviral effect of domperidone, 30 mg/day for 7 days (n = 87) versus placebo (n = 86) in outpatients with mild-to-moderate COVID-19.The primary efficacy endpoint was the reduction of viral load on day 4 as compared with baseline, estimated as the cycle thresholds to detect ORF1ab, N Protein and S Protein genes by RT-qPCR in saliva samples.The study findings do not prove the use of domperidone as antiviral in patients with COVID-19.

Cost-effectiveness of alginic acid in combination with proton pump inhibitor for the treatment of gastroesophageal reflux disease in systemic sclerosis patients.

BACKGROUND: Systemic sclerosis (SSc) patients often become refractory to proton pump inhibitors (PPI)-a standard treatment for gastroesophageal reflux disease (GERD)-and intolerant to PPI in combination with domperidone. PPI with alginic acid is an alternative treatment option, but alginic acid is costly. OBJECTIVES: We compared the costs and effectiveness of alginic acid plus PPI versus standard treatments (PPI with/without antacids as needed and lifestyle modifications) for GERD in SSc patients unsuitable for, or intolerant to, domperidone. METHODS: An economic evaluation using the Markov model was conducted among SSc patients aged between 40 and 65 years with GERD, having a partial or non-response to 4 weeks of standard-dose omeprazole (40 mg/day) and being unsuitable for or intolerant to domperidone. Using a societal perspective, we computed the incremental cost-effectiveness ratios (ICERs) in terms of Thai baht (THB) per quality-adjusted life-year (QALY) between a combination of alginic acid plus PPI and standard treatment for GERD. The lifetime time horizon was used. RESULTS: The ICER for alginic acid plus PPI versus standard treatments was 377 101 THB/QALY. According to the one-way sensitivity analysis, the cost of alginic acid was the most impactful parameter. If the market prices of alginic acid plus PPI were reduced by 61%, this treatment option would become cost-effective at the willingness-to-pay threshold of 160 000 THB/QALY (34.68 THB/USD data on 25 May 2023). Furthermore, if alginic acid were included in the public health insurance program, the national budget would be increased by 66 313 THB per patient, resulting in an overall budget increase of 5 106 101 to 8 885 942 THB compared with the standard treatment. CONCLUSIONS: Alginic acid plus PPI does not represent good value for money compared with the standard treatment among such SSc patients in Thailand unless its price is reduced significantly.

Green synthesis of quince/pectin cross-linked superporous hydrogel sponges for pH-regulated sustained domperidone delivery.

The present study aims to utilize green synthesis to fabricate stimuli-responsive, smart, quince/pectin cross-linked hydrogel sponges for the pH-regulated conveyance of domperidone. The designed hydrogel sponges were evaluated for a sol-gel fraction (%), swelling studies and kinetics, drug loading (%), electrolyte-responsive character, scanning electron microscopy (SEM), thermal analysis, drug-excipient compatibility studies (FTIR), X-ray diffraction (XRD) analysis, mechanical testing, in-vitro drug release studies, and acute oral toxicity studies. The drug loading (%) ranged from 67 to 85%. Hydrogel sponges displayed pH-responsive swelling potential, with optimum swelling in a phosphate buffer (pH 7.4) and insignificant swelling in an acidic buffer of pH 1.2. The prepared hydrogel sponges displayed second-order swelling dynamics. The FTIR data revealed the successful fabrication of the hydrogel sponges with the primary drug peaks remaining unchanged, demonstrating excipients-drug compatibility. SEM confirmed the rough, porous surface of hydrogel sponges with numerous cracks. XRD measurements revealed the transformation of the crystalline nature of domperidone into an amorphous one within the developed hydrogel sponges. Dissolution studies revealed little domperidone release in an acidic environment. However, hydrogel sponges exhibited release up to 10 h in phosphate buffer.The sponge's non-toxic or biocompatible character was confirmed through toxicological studies. Thus, the finding indicates that quince/pectin cross-linked hydrogel sponges are durable enough to deliver the domperidone to the gut for a longer time.

Domperidone Inhibits Clostridium botulinum C2 Toxin and Bordetella pertussis Toxin.

Bordetella pertussis toxin (PT) and Clostridium botulinum C2 toxin are ADP-ribosylating toxins causing severe diseases in humans and animals. They share a common translocation mechanism requiring the cellular chaperones Hsp90 and Hsp70, cyclophilins, and FK506-binding proteins to transport the toxins' enzyme subunits into the cytosol. Inhibitors of chaperone activities have been shown to reduce the amount of transported enzyme subunits into the cytosol of cells, thus protecting cells from intoxication by these toxins. Recently, domperidone, an approved dopamine receptor antagonist drug, was found to inhibit Hsp70 activity. Since Hsp70 is required for cellular toxin uptake, we hypothesized that domperidone also protects cells from intoxication with PT and C2. The inhibition of intoxication by domperidone was demonstrated by analyzing the ADP-ribosylation status of the toxins' specific substrates. Domperidone had no inhibitory effect on the receptor-binding or enzyme activity of the toxins, but it inhibited the pH-driven membrane translocation of the enzyme subunit of the C2 toxin and reduced the amount of PTS1 in cells. Taken together, our results indicate that domperidone is a potent inhibitor of PT and C2 toxins in cells and therefore might have therapeutic potential by repurposing domperidone to treat diseases caused by bacterial toxins that require Hsp70 for their cellular uptake.

Protective effect of exogenous melatonin on testicular histopathology and histomorphometry of adult rats with domperidone-induced hyperprolactinemia.

Hyperprolactinemia is a pathological condition resulting from increased prolactin that directly affects reproduction, as this condition inhibits the release of LH, FSH and gonadal steroidogenesis, bringing several negative clinical associations in reproduction. In contrast, melatonin (MEL) plays an important role in the regulation of steroidogenesis and modulates damages to the process of spermatogenesis. The objective was to analyze the protective effects of exogenous melatonin on the testis of hyperprolactinemic adult rats. Forty-eight male rats were used, divided into two treatment periods: 30 and 60 days, each treatment was subdivided into three groups: Control, Hyper (hyperprolactinemia), and Hyper+MEL (hyperprolactinemia and melatonin). Treatment with melatonin was 200 µg/100 g, subcutaneously. Induction of hyperprolactinemia was obtained with a dose of 4 mg/kg of domperidone, subcutaneously. The results of the histopathology demonstrated that the animals in the Hyper group presented degeneration of germ cells when compared to the control. In addition, the degenerations were presented in smaller quantities in the Hyper+MEL, in both treatment periods, evidencing the benefits of the melatonin in gonadal regeneration. The Hyper group of both treatment periods showed a decrease in tubular diameter, epithelium height, and tubular area, in addition to a decrease in Sertoli cells, when compared to the control and the Hyper+MEL group. In conclusion, the hyperprolactinemia can affect the germinal epithelium and testicular microstructure; the exogenous melatonin has a protective effect against hyperprolactinemia, reducing testicular damage.

Domperidone Protects Cells from Intoxication with Clostridioides difficile Toxins by Inhibiting Hsp70-Assisted Membrane Translocation.

Clostridioides difficile infections cause severe symptoms ranging from diarrhea to pseudomembranous colitis due to the secretion of AB-toxins, TcdA and TcdB. Both toxins are taken up into cells through receptor-mediated endocytosis, autoproteolytic processing and translocation of their enzyme domains from acidified endosomes into the cytosol. The enzyme domains glucosylate small GTPases such as Rac1, thereby inhibiting processes such as actin cytoskeleton regulation. Here, we demonstrate that specific pharmacological inhibition of Hsp70 activity protected cells from TcdB intoxication. In particular, the established inhibitor VER-155008 and the antiemetic drug domperidone, which was found to be an Hsp70 inhibitor, reduced the number of cells with TcdB-induced intoxication morphology in HeLa, Vero and intestinal CaCo-2 cells. These drugs also decreased the intracellular glucosylation of Rac1 by TcdB. Domperidone did not inhibit TcdB binding to cells or enzymatic activity but did prevent membrane translocation of TcdB's glucosyltransferase domain into the cytosol. Domperidone also protected cells from intoxication with TcdA as well as CDT toxin produced by hypervirulent strains of Clostridioides difficile. Our results reveal Hsp70 requirement as a new aspect of the cellular uptake mechanism of TcdB and identified Hsp70 as a novel drug target for potential therapeutic strategies required to combat severe Clostridioides difficile infections.

Effective nose-to-brain drug delivery using a combination system targeting the olfactory region in monkeys.

The nose-to-brain (N2B) pathway has garnered attention because it transports drugs directly into the brain. Although recent studies have suggested the necessity of selective drug administration to the olfactory region for effective N2B drug delivery, the importance of delivering the formulation to the olfactory region and the detailed pathway involved in drug uptake in primates brain remain unclear. Here, we developed a combination system for N2B drug delivery comprising a proprietary mucoadhesive powder formulation and a dedicated nasal device (N2B-system) and evaluated it for nasal drug delivery to the brain in cynomolgus monkeys. This N2B-system demonstrated a much greater formulation distribution ratio in the olfactory region in an in vitro experiment using a 3D-printed nasal cast and in vivo experiment using cynomolgus monkeys, as compared to that in other nasal drug delivery systems that comprise of a proprietary nasal powder device developed for nasal absorption and vaccination and a commercially available liquid spray. Additionally, Texas Red-labeled dextran (TR-DEX, 3 kDa) was administered using the N2B-system to estimate the drug transition pathway from the nasal cavity to the brain. TR-DEX preferentially localized to the olfactory epithelium and reached the olfactory bulb through the cribriform foramina. Moreover, domperidone, a model drug with poor blood-brain barrier permeability, was administered to assess the brain uptake of medicine after olfactory region-selective administration by using the N2B-system. Domperidone accumulation in the brain was evaluated using positron emission tomography with intravenously administered [18F]fallypride based on competitive inhibition of the dopamine D2 receptor (D2R). Compared to other systems, the N2B-system significantly increased D2R occupancy and domperidone uptake in the D2R-expressing brain regions. The current study reveals that the olfactory region of the nasal cavity is a suitable target for efficient nasal drug delivery to the brain in cynomolgus monkeys. Thus, the N2B-system, which targets the olfactory region, provides an efficient approach for developing effective technology for nasal drug delivery to the brain in humans.

The Transfer of Domperidone into Human Milk Remains Low at High Doses.

Domperidone is a dopamine-2 (D2) receptor antagonist that stimulates the release of stored prolactin in the anterior pituitary. It is prescribed off-label in Canada and Australia to promote lactation in prolactin-deficient women. The case of a 43-year-old woman taking a high daily dose of domperidone (160 mg) is described from the InfantRisk Center Human Milk Biorepository. Milk samples were analyzed using a high-performance liquid chromatography-mass spectrometry method, detecting an average domperidone concentration of 7.0 ng/mL (range 6.2 to 8.4 ng/mL). Even at high doses, the transfer of domperidone into breast milk was negligible with a relative infant dose (RID) of 0.05%. The RID estimates the infant's potential exposure to a drug via lactation as a percentage of the weight-adjusted maternal dose. The standard threshold for reasonable infant exposure is an RID of 10%.

Drugs in Focus: Domperidone.

Domperidone is a peripheral dopamine-2 receptor antagonist with prokinetic and antiemetic properties. Its prokinetic effects are mainly manifest in the upper gastrointestinal (GI) tract. Currently its use is restricted to relief of nausea and vomiting in children older than 12 years for a short period of time. However, among (pediatric) gastroenterologists, domperidone is also used outside its authorized indication ("off label") for treatment of symptoms associated with gastro-esophageal reflux disease, dyspepsia, and gastroparesis. Little is known about its efficacy in the treatment of GI motility disorders in children and controversial data have emerged in the pediatric literature. As its use is off label, appropriate knowledge of its efficacy is helpful to support an "off label/on evidence" prescription. Based on this, the purpose of this review is to summarize all evidence on the efficacy of domperidone for the treatment of GI disorders in infants and children and to report an overview of its pharmacological properties and safety profile.

Oral administration of domperidone in the first or third week of lactation: Effects on prolactin concentrations and mammary gene expression in sows and piglet growth.

The scope of the present study is endocrine and metabolic control of sow lactation. This project aimed to determine the impact of increasing prolactin concentrations via oral administration of the dopamine receptor antagonist domperidone in the first or third week of lactation in sows. Effects on sow hormonal and metabolic status, lactational performance, and gene expression in mammary epithelial cells were determined. Primiparous sows were divided in 3 treatments: 1) 10 mL of vehicle (table syrup) per os twice daily during the first and third weeks of lactation (Control, CTL, n = 23), 2) 0.5 mg/kg of domperidone per os twice daily during the first week of lactation (LACT1, n = 23), or 3) 0.5 mg/kg of domperidone given per os twice daily during the third week of lactation (LACT3, n = 22). Treated sows also received 10 mL of the vehicle twice daily during the other treatment period. Litter size was standardized to 12 ± 1 and piglets were weighed at birth, 24 h, and on d 8, 15, 22 (weaning), 35, and 56. Sow feed intake was recorded daily. Representative milk samples were obtained on d 7 and 21 of lactation for compositional analyses, and milk fat globules were used to measure mRNA abundances of various genes. Jugular blood samples were obtained from sows on d 1, 7, 14, and 21 of lactation to measure concentrations of prolactin, IGF-1, insulin, urea, and FFA. Concentrations of prolactin were increased (P < 0.01) at the end of the 7-d treatment period with domperidone, whether imposed in the first (LACT1) or third (LACT 3) week of lactation. No other blood variables were affected by treatments and neither was milk composition (P > 0.10). Sow BW, backfat thickness, or feed intake were not altered by treatments (P > 0.10), but piglet BW tended to be greater in litters from LACT3 compared with CTL sows on d 22 and 35 (P ≤ 0.10). Gene expression of EGF in milk fat globules tended to be (LACT1, P < 0.10) or was increased (LACT3, P < 0.05) after treatment, and the effect in LACT1 sows was maintained until d 21 of lactation. The mRNA abundance of SPP1 was increased (P < 0.05) in LACT1 vs CTL sows on d 7, and that of 3 major milk proteins tended to be (CSN1S2 and WAP, P < 0.10) or was greater (LALBA, P < 0.05) in LACT3 vs CTL sows on d 21 of lactation. Oral administration of domperidone during the first or third week of lactation increased prolactin concentrations and altered mRNA abundances of selected genes in milk fat globules. Yet, only the LACT 3 treatment positively affected piglet performance.