Gestational valproic acid exposure enhances facial stimulation-evoked cerebellar mossy fiber-granule cell transmission via GluN2A subunit-containing NMDA receptor in offspring mice.

Valproic acid (VPA) is one of the most effective antiepileptic drugs, and exposing animals to VPA during gestation has been used as a model for autism spectrum disorder (ASD). Numerous studies have shown that impaired synaptic transmission in the cerebellar cortical circuits is one of the reasons for the social deficits and repetitive behavior seen in ASD. In this study, we investigated the effect of VPA exposure during pregnancy on tactile stimulation-evoked cerebellar mossy fiber-granule cell (MF-GC) synaptic transmission in mice anesthetized with urethane. Three-chamber testing showed that mice exposed to VPA mice exhibited a significant reduction in social interaction compared with the control group. In vivo electrophysiological recordings revealed that a pair of air-puff stimulation on ipsilateral whisker pad evoked MF-GC synaptic transmission, N1, and N2. The evoked MF-GC synaptic responses in VPA-exposed mice exhibited a significant increase in the area under the curve (AUC) of N1 and the amplitude and AUC of N2 compared with untreated mice. Cerebellar surface application of the selective N-methyl-D-aspartate (NMDA) receptor blocker D-APV significantly inhibited facial stimulation-evoked MF-GC synaptic transmission. In the presence of D-APV, there were no significant differences between the AUC of N1 and the amplitude and AUC of N2 in the VPA-exposed mice and those of the untreated mice. Notably, blockade of the GluN2A subunit-containing, but not the GluN2B subunit-containing, NMDA receptor, significantly inhibited MF-GC synaptic transmission and decreased the AUC of N1 and the amplitude and AUC of N2 in VPA-exposed mice to levels similar to those seen in untreated mice. In addition, the GluN2A subunit-containing NMDA receptor was expressed at higher levels in the GC layer of VPA-treated mice than in control mice. These results indicate that gestational VPA exposure in mice produces ASD-like behaviors, accompanied by increased cerebellar MF-GC synaptic transmission and an increase in GluN2A subunit-containing NMDA receptor expression in the offspring.

Effects of agmatine on radial-arm maze memory performance and autistic-like behaviors in a male rat model of autism.

BACKGROUND: Autism spectrum disorder (ASD) is the fastest-growing child neuropsychiatric condition. Cognitive dysfunctions such as memory impairments are experienced by patients along with social disturbances and repetitive/stereotypic movements. We have used the radial arm maze (RAM), for measurement of working and reference memory errors in an animal model of autism. In addition, the potential effects of agmatine, an endogenous NMDA antagonist, on RAM performance and autistic-like behaviors were assessed. METHODS: Autism was modeled by valproic acid (VPA) administration at gestational Day 12.5. Autism-associated behaviors in male offspring were examined in an open field test (OFT) and three-chambered test (TCT) on postnatal days 50-51. Thereafter, the animals were trained in the RAM (PND 55) until they attained the criteria of 80% correct choices during five consecutive trials. Forty-eight hours after the acquisition of criteria, agmatine was injected 30 min before subsequent behavioral testing, which included the retention phase of the RAM, OFT, and TCT. RESULTS: VPA-treated and intact rats showed the same performance in RAM, and acute injection of agmatine rescued social and anxiety-like behavior induced by VPA without the effect on RAM. CONCLUSION: In a rat model of autism, spatial learning, and memory did not change. Agmatine rescued social and anxiety-like behavior in autistic animals.

In women with epilepsy, use of valproate in the second half of pregnancy was linked to autism in offspring.

SOURCE CITATION: Hernández-Díaz S, Straub L, Bateman BT, et al. Risk of autism after prenatal topiramate, valproate, or lamotrigine exposure. N Engl J Med. 2024;390:1069-1079. 38507750.

Modulation of keap-1/Nrf2/HO-1 and NF-ĸb/caspase-3 signaling pathways by dihydromyricetin ameliorates sodium valproate-induced liver injury.

Nuclear factor erythroid factor 2 (Nrf2) is the key regulatory of the antioxidant response elements. Also, Nrf2 interacts with nuclear factor kappa B (NF-ĸB) to inhibit subsequent inflammatory cascade. Activation of Nrf2 signaling ameliorates drug-induced liver injury. Sodium valproate (SVP) is an anti-epilepsy drug with a hepatotoxic adverse effect that restricts its clinical use. In this study, coadministration of Dihydromyricetin (DHM), a natural flavonoid, with SVP to rats upregulated gene expression of Nrf2 and its downstream gene, heme oxygenase 1 (HO-1), while suppressed the Nrf2 repressor, Keap-1. Additionally, DHM led to downregulation of proinflammatory factors in liver tissues, including NF-ĸB, interleukin 1 beta (IL-1ß), and tumor necrosis factor alpha (TNF-α). This was accompanied by a decrease in the proapoptotic protein (cleaved caspase-3) expression level. Furthermore, biochemical and histopathological studies showed that DHM treatment improved liver function and lipid profile while decreased inflammatory cell infiltration, congestion, and hepatocellular damage. According to our knowledge, prior research has not examined the protective effect of DHM on the liver injury induced by SVP. Consequently, this study provides DHM as a promising herbal medication that, when used with SVP, can prevent its induced hepatotoxicity owing to its potential anti-oxidative, anti-inflammatory, and anti-apoptotic properties.

Successful Synergistic Use of Gabapentin With Other Antiepileptic Drugs in the Management of Lance-Adams Syndrome Complicated by Alcohol Withdrawal Seizures: A Case Report.

OBJECTIVE: Lance-Adams syndrome is a rare and debilitating disorder characterized by successful cardiopulmonary resuscitation resulting in myoclonus activity. Alcohol withdrawal seizures from alcohol use disorder may further exacerbate Lance-Adams syndrome. We aim to present a case of Lance-Adams syndrome complicated by alcohol withdrawal seizures and successfully treated with a combination of valproate, clonazepam, and gabapentin. MATERIALS AND METHODS: The patient's electronic medical record, direct patient care experiences, and a comprehensive literature search were used for this case report. We report a 41-year-old male patient with Lance-Adams syndrome with concurrent alcohol use disorder. Treatment was improved when adding gabapentin for alcohol use disorder treatment, alongside combination antiepileptic therapy. A PubMed search was conducted to examine Lance-Adams syndrome case reports of successful combination antiepileptic therapy, with a secondary evaluation of patients with concurrent alcohol use disorder. RESULTS: The literature search yielded 18 articles, which resulted in 21 individual cases in which combination antiepileptic drug therapy was successful in treating myoclonus secondary to Lance-Adams syndrome; however, none of the case reports utilized gabapentin synergistically. One case described Lance-Adams syndrome complicated by alcohol consumption and similar to our patient, the patient used alcohol to abolish myoclonic activity. CONCLUSIONS: To the best of our knowledge, this is the first case report documenting a patient with Lance-Adams syndrome and concurrent alcohol use disorder, with a positive effect of gabapentin use. Gabapentin, when used for alcohol use disorder treatment, may be an appropriate adjunct agent in the management of patients receiving combination antiepileptic therapy for the treatment of Lance-Adams syndrome.

Ectonucleotidase Activity in Smooth Muscle Tissues of Rats with a Valproate Model of Autism.

Ectonucleotidases play an important role in regulating the level of extracellular nucleotides and nucleosides and are an important part of the regulation of the effects of adenosine and ATP on adenosine and P2 receptors, respectively. We have previously established the ambiguous effect of P2 receptor agonists on the contractile activity of smooth muscle tissue in rats with the valproate model of autism. In this work, HPLC was used to evaluate the activity of ectonucleotidases in the smooth muscle tissues of the internal organs of rats with a valproate model of autism. The activity of ectonucleotidases was significantly higher in the smooth muscle tissues of the duodenum, vas deferens, and bladder, but lower in the ileum and uterus. The results obtained make it possible to compare the activity of ectonucleotidases identified here with changes in P2 receptor-mediated contractility of smooth muscle tissues revealed in our previous experiments.

Erroneous predictive coding across brain hierarchies in a non-human primate model of autism spectrum disorder.

In autism spectrum disorder (ASD), atypical sensory experiences are often associated with irregularities in predictive coding, which proposes that the brain creates hierarchical sensory models via a bidirectional process of predictions and prediction errors. However, it remains unclear how these irregularities manifest across different functional hierarchies in the brain. To address this, we study a marmoset model of ASD induced by valproic acid (VPA) treatment. We record high-density electrocorticography (ECoG) during an auditory task with two layers of temporal control, and applied a quantitative model to quantify the integrity of predictive coding across two distinct hierarchies. Our results demonstrate a persistent pattern of sensory hypersensitivity and unstable predictions across two brain hierarchies in VPA-treated animals, and reveal the associated spatio-spectro-temporal neural signatures. Despite the regular occurrence of imprecise predictions in VPA-treated animals, we observe diverse configurations of underestimation or overestimation of sensory regularities within the hierarchies. Our results demonstrate the coexistence of the two primary Bayesian accounts of ASD: overly-precise sensory observations and weak prior beliefs, and offer a potential multi-layered biomarker for ASD, which could enhance our understanding of its diverse symptoms.

Reversal of electrophysiological and behavioral deficits mediated by 5-HT7 receptor upregulation following LP-211 treatment in an autistic-like rat model induced by prenatal valproic acid exposure.

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by alterations and imbalances in multiple brain neurochemical systems, particularly the serotonergic neurotransmission. This includes changes in serotonin (5-HT) levels, aberrations in 5-HT transporter activity, and decreased synthesis and expression of 5-HT receptors (5-HT7Rs). The exact role of the brain 5-HT system in the development of ASD remains unclear, with conflicting evidence on its involvement. Recently, we have reported research has shown a significant decrease in serotonergic neurons originating from the raphe nuclei and projecting to the CA1 region of the dorsal hippocampus in autistic-like rats. Additionally, we have shown that chronic activation of 5-HT7Rs reverses the effects of autism induction on synaptic plasticity. However, the functional significance of 5-HT7Rs at the cellular level is still not fully understood. This study presents new evidence indicating an upregulation of 5-HT7R in the CA1 subregion of the hippocampus following the induction of autism. The present account also demonstrates that activation of 5-HT7R with its agonist LP-211 can reverse electrophysiological abnormalities in hippocampal pyramidal neurons in a rat model of autism induced by prenatal exposure to VPA. Additionally, in vivo administration of LP-211 resulted in improvements in motor coordination, novel object recognition, and a reduction in stereotypic behaviors in autistic-like offspring. The findings suggest that dysregulated expression of 5-HT7Rs may play a role in the pathophysiology of ASD, and that agonists like LP-211 could potentially be explored as a pharmacological treatment for autism spectrum disorder.

cGAS-STING-TBK1 Signaling Promotes Valproic Acid-Responsive Human Cytomegalovirus Immediate-Early Transcription during Infection of Incompletely Differentiated Myeloid Cells.

Repression of human cytomegalovirus (HCMV) immediate-early (IE) gene expression is a key regulatory step in the establishment and maintenance of latent reservoirs. Viral IE transcription and protein accumulation can be elevated during latency by treatment with histone deacetylase inhibitors such as valproic acid (VPA), rendering infected cells visible to adaptive immune responses. However, the latency-associated viral protein UL138 inhibits the ability of VPA to enhance IE gene expression during infection of incompletely differentiated myeloid cells that support latency. UL138 also limits the accumulation of IFNß transcripts by inhibiting the cGAS-STING-TBK1 DNA-sensing pathway. Here, we show that, in the absence of UL138, the cGAS-STING-TBK1 pathway promotes both IFNß accumulation and VPA-responsive IE gene expression in incompletely differentiated myeloid cells. Inactivation of this pathway by either genetic or pharmacological inhibition phenocopied UL138 expression and reduced VPA-responsive IE transcript and protein accumulation. This work reveals a link between cytoplasmic pathogen sensing and epigenetic control of viral lytic phase transcription and suggests that manipulation of pattern recognition receptor signaling pathways could aid in the refinement of MIEP regulatory strategies to target latent viral reservoirs.

Effectiveness of Lidocaine Infusion Versus Valproate Infusion for Pediatric Status Migrainosus.

OBJECTIVE: To compare the efficacy (as measured by time to resolution of pain) and safety of valproate infusion and lidocaine infusion in the treatment of pediatric status migrainosus. METHODS: We conducted a single-center retrospective cohort study from March 2014 to June 2021 evaluating children and adolescents who received a lidocaine or sodium valproate infusion for the treatment of status migrainosus. During the study period, lidocaine infusion was exclusively used before March 2016, whereas sodium valproate infusion was exclusively used afterward. RESULTS: A total of 31 patients received lidocaine and 63 received sodium valproate infusion. Patients in the lidocaine group achieved significantly faster control of pain with median hours to pain free of 11.7 (interquartile range, 3.8-32.3) hours compared with 43.4 (interquartile range 13.8-68.7) hours in the valproate group (P = .002). At discharge, 21 of 31 (67.7%) of patients receiving lidocaine were pain-free compared with 26 of 59 (44.1%) of patients receiving valproate (P = .03). There were significantly more infusion interruptions of valproate compared with lidocaine for various patient-related factors (16/63, 25.4% vs 1/31, 3.2%; P = .009). More adverse effects were observed with valproate (42/63, 67%) compared with lidocaine (1/31, 3.2%; P < .001). The significant difference in hours to pain control persisted after adjustment for sex, race, age, BMI, presence of comorbidities, and pain score at admission. All patients in both groups completed the infusions and were discharged from the hospital. CONCLUSIONS: Intravenous lidocaine infusion is associated with superior pain control and a better safety profile compared with intravenous sodium valproate infusion in status migrainosus.

Influence of the glutamate-glutamine cycle on valproic acid-associated hepatotoxicity in pediatric patients with epilepsy.

INTRODUCTION: Although valproic acid is generally well tolerated, hepatotoxicity is a common side effect in patients receiving long-term treatment. However, the mechanisms underlying valproic acid-associated hepatotoxicity remain elusive. METHODS: To investigate the mechanisms and explore the potential risk factors for valproic acid-associated hepatotoxicity, 165 age-matched pediatric patients were recruited for laboratory tests and glutamate-glutamine cycle analysis. RESULTS: The concentration of glutamate in patients with hepatotoxicity was significantly greater than that in control patients, while the concentration of glutamine in patients with hepatotoxicity was significantly lower than that in control patients (P <0.05). In addition, the frequencies of the heterozygous with one mutant allele and homozygous with two mutant alleles genotypes in glutamate-ammonia ligase rs10911021 were significantly higher in the hepatotoxicity group than those in the control group (47.1 percent versus 32.5 percent, P = 0.010; 17.6 percent versus 5.2 percent, P = 0.001, respectively). Moreover, heterozygous carriers with one mutant allele and homozygous carriers with two mutant alleles genotypes of glutamate-ammonia ligase rs10911021 exhibited significant differences in the concentrations of glutamine and glutamate concentrations (P ˂ 0.001 and P = 0.001, respectively) and liver function indicators (activities of aspartate aminotransferase, alanine aminotransferase, and gamma-glutamyl transferase, P <0.001, respectively). Furthermore, logistic regression analysis indicated that glutamate-ammonia ligase rs10911021 (P = 0.002, odds ratio: 3.027, 95 percent confidence interval, 1.521 - 6.023) and glutamate (P = 0.001, odds ratio: 2.235, 95 percent confidence interval, 1.369 - 3.146) were associated with a greater risk for hepatotoxicity, while glutamine concentrations were negatively associated with hepatotoxicity (P = 0.001, odds ratio: 0.711, 95 percent confidence interval, 0.629 - 0.804). DISCUSSION: Understanding pharmacogenomic risks for valproic acid induced hepatotoxicity might help direct patient specific care. Limitations of our study include the exclusive use of children from one location and concomitant medication use in many patients. CONCLUSION: Perturbation of the glutamate-glutamine cycle is associated with valproic acid-associated hepatotoxicity. Moreover, glutamate-ammonia ligase rs10911021, glutamate and glutamine concentrations are potential risk factors for valproic acid-associated hepatotoxicity.

Trends in Antiseizure Medication Initiation, Switch, or Termination in Patients With Newly Diagnosed Epilepsy: A Nationwide Study.

BACKGROUND AND OBJECTIVES: Few studies evaluate physicians' choice of antiseizure medication (ASM) to treat patients with newly diagnosed epilepsy. The objective of this study was to analyze the choice of ASM and its use by age, sex, psychiatric comorbidities, and concurrent treatment with other drugs (antidepressant medications and contraceptives) in patients who initiated epilepsy treatment using monotherapy. METHODS: Included in this study were persons (any age) with an incident hospital diagnosis of epilepsy during 2010-2022 in the Swedish Patient Register (SPR), preceding a first dispensing of any ASM (as reported in the Swedish Prescribed Drug Register, SPDR) for the period 2010-2022. Incident patients were identified using retrospective information during 2000-2009 in the SPR. Primary outcome was first dispensed ASM by age, sex, comorbidity, and comedication with antidepressants or contraceptives (SPDR). Secondary outcomes were time to ASM switch or termination assessed by survival analyses. RESULTS: Of 67,984 patients included (mean age 46; 46% female), 66,441 initiated ASM treatment using monotherapy. Relative risk (RR) for initiating treatment using monotherapy did not differ between age groups, sex, or patients with concurrent treatment with antidepressants, contraceptives, or psychiatric illness (RR and 95% CI did include 1.0). The share initiating treatment using levetiracetam increased from 10% in 2010 to 55% in 2022; valproic acid: 10%-5%. The likelihood of initiating treatment using 1 of the 5 most frequent ASMs differed between all compared groups (0.3 < RR < 1; 95% CI < 1; 1 < RR < 15; 1 <95% CI). Seven percent of female patients of childbearing age initiated treatment with valproic acid, levetiracetam was the most frequent initial ASM in patients with psychiatric comorbidity (40.2%), and lamotrigine the most prescribed initial ASM to women on contraceptives (50.4%). Highest likelihoods of treatment termination were found among children (1.72 < RR < 3.07; 1 <95% CI) and among patients with psychiatric comorbidity (initiated on carbamazepine, RR 1.38; 1 <95% CI or lamotrigine, RR 1.31; 1 <95% CI). Thirty-one percent to 47% of patients switched from an initial monotherapy to a new monotherapy within 5 years. Twenty percent to 42% terminated ASM treatment within 5 years. DISCUSSION: Levetiracetam and lamotrigine were the most frequently dispensed initial ASMs, also among patients with comorbidities or comedications complicating the use of these ASMs, highlighting the need for improved education of prescribers concerning ASM selection in relation to individual patient characteristics. Use of ASMs in hospital is not captured in the SPDR.

Effects of (S)-3,4-DCPG, an mGlu8 receptor agonist, on hippocampal long-term potentiation at perforant pathway-dentate gyrus synapses in prenatal valproic acid-induced rat model of autism.

Autism spectrum disorder (ASD) is a pervasive neurodevelopmental condition characterized by social interaction deficits, communication impairments, repetitive behaviors, and sensory sensitivities. While the etiology of ASD is multifaceted, abnormalities in glutamatergic neurotransmission and synaptic plasticity have been implicated. This study investigated the role of metabotropic glutamate receptor 8 (mGlu8) in modulating long-term potentiation (LTP) in a rat model of ASD induced by prenatal valproic acid (VPA) exposure. To induce an animal model with autism-like characteristics, pregnant rats received an intraperitoneal injection of 500 mg/kg of sodium valproate (NaVPA) on embryonic day 12.5. High-frequency stimulation was applied to the perforant path-dentate gyrus (PP-DG) synapse to induce LTP, while the mGlu8 receptor agonist (S)-3,4-dicarboxyphenylglycine (DCPG) was administered into the DG. The results revealed that VPA-exposed rats exhibited reduced LTP compared to controls. DCPG had contrasting effects, inhibiting LTP in controls and enhancing it in VPA-exposed rats. Moreover, reduced social novelty preference index (SNPI) in VPA-exposed rats was reversed by intra-DG administration of S-3,4-DCPG. In conclusion, our study advances our understanding of the complex relationship between glutamatergic neurotransmission, synaptic plasticity, and VPA-induced autism model. The findings suggest that mGlu8 receptor dysfunction plays a role in the impaired synaptic plasticity seen in ASD.

Valproate Use During Spermatogenesis and Risk to Offspring.

Importance: Concerns exist about teratogenic and long-term neurodevelopmental outcomes of paternal use of valproate during spermatogenesis. Objective: To evaluate the association between paternal use of valproate during spermatogenesis and offspring risk of congenital malformations and neurodevelopmental disorders. Design, Setting, and Participants: This nationwide cohort study included 1 235 353 singletons born in Denmark between January 1, 1997, and December 31, 2017, identified in the Medical Birth Register; 1336 children had fathers who had filled prescriptions for valproate during spermatogenesis. Congenital malformations were identified in the first year of life and neurodevelopmental disorders were identified from 1 year of age until December 31, 2018. Statistical analysis was performed March 2024. Exposures: Paternal valproate exposure was defined as fathers who filled 1 or more prescriptions for valproate immediately before or during the time of spermatogenesis (ie, 3 months prior to conception). Main Outcomes and Measures: Children with major congenital malformations in the first year of life and with neurodevelopmental disorders before death or end of follow-up were identified in Danish health registers. Log-binomial regression was used to estimate adjusted relative risks (ARRs) of congenital malformations, and Cox proportional hazards regression was used to estimate adjusted hazards ratios (AHRs) of neurodevelopmental disorders, adjusted for relevant confounders. Results: Among 1 235 353 live births (634 415 boys [51.4%] and 600 938 girls [48.6%]), 1336 children (0.1%) had fathers who filled prescriptions for valproate during spermatogenesis. The median follow-up was 10.1 years (IQR, 5.1-14.8 years) for valproate-exposed children and 10.3 years (IQR, 5.2-15.6 years) for valproate-unexposed children. A total of 43 903 children (3.6%) received a diagnosis of major congenital malformations in the first year of life, and 51 633 children (4.2%) received a diagnosis of neurodevelopmental disorders during follow-up. When comparing the risk among valproate-exposed children with that among unexposed children, the ARR of major congenital malformations was 0.89 (95% CI, 0.67-1.18), the AHR of neurodevelopmental disorders was 1.10 (95% CI, 0.88-1.37), and the AHR of autism spectrum disorder was 0.92 (95% CI, 0.65-1.30). In analyses addressing the robustness of the findings (ie, dose-response analyses, sibling analyses, analyses restricted to children of fathers with epilepsy, analyses that used children with paternal lamotrigine exposure as active comparator, and analyses that used children with paternal exposure to valproate only before spermatogenesis as a negative control exposure), there still was no increased risk of any of the included end points. Conclusions and Relevance: In all analyses based on this large Danish cohort study, results suggest that exposure to valproate during spermatogenesis was not associated with offspring risk of congenital malformations or neurodevelopmental disorders, including autism spectrum disorder.

Effect of SCN1Aand SCN2A gene polymorphisms on the efficacy of valproic acid treatment in Chinese children with epilepsy.

OBJECTIVE: Epilepsy patients exhibit considerable differences in their response to sodium valproate (VPA) therapy, a phenomenon that might be attributed to individual genetic variances. The role of genetic variations, specifically in sodium channels encoded by SCN1A and SCN2A genes, in influencing the effectiveness of VPA in treating epilepsy is still debated. This research focuses on examining the impact of these genetic polymorphisms on the efficacy of VPA therapy among pediatric epilepsy patients in China. METHODS: Five single nucleotide polymorphisms (SNPs), including SCN1A (rs10188577, rs2298771, rs3812718) and SCN2A (rs2304016, rs17183814), were genotyped in 233 epilepsy patients undergoing VPA therapy. The associations between genotypes and the antiepileptic effects of VPA were assessed, with 128 patients categorized as VPA responders and 105 as VPA non-responders. RESULTS: In the context of VPA monotherapy, SCN1A rs2298771 and SCN2A rs17183814 were found to be significantly associated with VPA response (P< 0.05). CONCLUSION: Our study suggests the findings of this investigation indicate that the polymorphisms SCN1A rs2298771 and SCN2A rs17183814 could potentially act as predictive biomarkers for the responsiveness to VPA among Chinese epilepsy patients.

Model-Based Bioequivalence Analysis to Assess and Predict the Relative Bioavailability of Valproic Acid Formulations.

BACKGROUND AND OBJECTIVE: Model-based bioequivalence (MBBE) encompasses the use of nonlinear mixed effect models supporting the estimation of pharmacokinetic endpoints to assess the relative bioavailability between multi-source drug products. This application emerges as a valuable alternative to the standard non-compartmental analysis (NCA) in bioequivalence (BE) studies in which dense sampling is not possible. In this work, we aimed to assess the application of MBBE compared to traditional methods in evaluating the relative bioavailability of two formulations with different drug release properties. Additionally, we sought to predict the performance of a modified-release formulation in a multiple-dose scenario, leveraging data from a single-dose study. METHODS: MBBE analysis was implemented to estimate the BE endpoints (90% CI for the Test/Reference geometric mean ratio, T/R GMR) in area under the concentration-time curve (AUC) and maximum concentration (Cmax) using data from a single-dose, 2-period, 2-sequence BE study performed in 14 healthy subjects between a locally developed valproic acid extended-release formulation (Test) and the brand-name delayed-release formulation (Reference). RESULTS: Results were compared with the standard approach, revealing that MBBE analysis achieved higher discrimination between formulations for Cmax, addressing limitations of the experimental sampling design and highlighting an advantage for this model-based analysis even when rich data are available. Additionally, the bioequivalence outcome under the multiple-dose scenario was predicted through a simulation-based study for both total and unbound valproic acid concentrations, considering the impact of valproic acid saturable binding on BE conclusions. CONCLUSIONS: The MBBE analysis was superior to the NCA approach in detecting product-related differences, overcoming limitations in the study experimental design. Predictions for the multiple-dose scenario preclude that the extended-release properties of the Test formulation would persist at steady state, resulting in lower peak-to-trough fluctuation and bioequivalent performance in terms of the extent of drug absorption. Overall, these results should discourage unnecessary experimentation in healthy subjects.

Assessment of the Novel Anti-Seizure Potential of Validamycin A Using Zebrafish Epilepsy Model.

Epilepsy is a prevalent neurological disorder characterized by recurrent seizures. Validamycin A (VA) is an antibiotic fungicide that inhibits trehalase activity and is widely used for crop protection in agriculture. In this study, we identified a novel function of VA as a potential anti-seizure medication in a zebrafish epilepsy model. Electroencephalogram (EEG) analysis demonstrated that VA reduced pentylenetetrazol (PTZ)-induced seizures in the brains of larval and adult zebrafish. Moreover, VA reduced PTZ-induced irregular movement in a behavioral assessment of adult zebrafish. The developmental toxicity test showed no observable anatomical alteration when the zebrafish larvae were treated with VA up to 10 µM within the effective range. The median lethal dose of VA in adult zebrafish was > 14,000 mg/kg. These results imply that VA does not demonstrate observable toxicity in zebrafish at concentrations effective for generating anti-seizure activity in the EEG and alleviating abnormal behavior in the PTZ-induced epileptic model. Furthermore, the effectiveness of VA was comparable to that of valproic acid. These results indicate that VA may have a potentially safer anti-seizure profile than valproic acid, thus offering promising prospects for its application in agriculture and medicine.