Highly purified cannabidiol (CBD) in CDKL5 deficiency disorder (CDD): Open-label prospective study

Objective: CDKL5 deficiency disorder (CDD) is an early-onset developmental and epileptic encephalopathy characterized by frequent drug-resistant seizures, cerebral visual impairment, motor dysfunction, and sleep and gastrointestinal disturbances. Preliminary evidence suggests that highly purified cannabidiol (CBD) may reduce seizure frequency, but data on its effects on comorbidities are lacking. This study aimed to evaluate the efficacy and safety of CBD in individuals with CDD.

Methods: We conducted a prospective, open-label, single-center study including patients with CDD aged >1 year. Outcomes included motor seizure frequency, caregiver- and clinician-rated Clinical Global Impression (CGI), and changes in sleep, motor abilities, and EEG at 3, 6, and 12 months. CBD plasma levels were measured with High-Performance Liquid chromatography-Mass Spectrometry (HPLC-MS).

Results: Eight of nine patients (all females; median age 10 years, range 1-24) completed the study, with a retention rate at 12 months of 8/9 (89%). One discontinued at 6 months due to a skin rash. A > 50% seizure reduction was observed in 8/9 patients at 3 months, 6/9 at 6 months, and 1/8 at 12 months. Seven patients showed some degree of vigilance improvements, three in motor performance, and two in sleep and constipation. All caregivers reported at least minimal overall improvement (CGI score 3) at 3 months, and three reported marked improvement (CGI score 2), with a peak at 3 months. Five patients showed adverse events during the trial, but none were considered serious. The median CBD dose at all time-points was 15.6 mg/kg/day (IQR 10.0-18.9) corresponding to a plasma dose of 69.9 ng/mL (IQR 29.8-114.6) and the median concentration/dose ratio was 4.7 (IQR 2.7-6.8).

Significance: The safety and efficacy of highly purified CBD in CDD were consistent with previous reports in the literature, with possible benefits beyond seizure control. Further studies are warranted to assess non-seizure outcomes and compare long-term efficacy across treatment options.

Plain language summary: We studied nine girls with CDKL5 deficiency disorder who had frequent, hard-to-treat seizures. They received cannabidiol for up to 1 year, added to their usual medicines. Most children had fewer seizures in the first months of treatment. Some families also noticed better alertness, eye contact, movement, sleep, or constipation. Side effects were usually mild and manageable. Although seizure frequency often returned to baseline by the end of the study, most families chose to continue cannabidiol. Because this was a small study without a placebo group, these results are preliminary, and larger controlled trials are needed.”

https://pubmed.ncbi.nlm.nih.gov/41677102

“In this exploratory prospective open-label trial, we suggest that CBD may be an effective and relatively safe therapeutic option in patients with CDD, which warrants further investigation through randomized controlled trials. CBD may be associated with effects not only on seizures but also on awareness, sleep, and motor functions.”

https://onlinelibrary.wiley.com/doi/10.1002/epi4.70213

Synergistic Neuroprotection by Cannabis sativa and Tilia × viridis: Attenuation of Hippocampal Neurons Glutamate-Induced Oxidative Stress and LPS-Driven Microglial Inflammation

“Throughout history, Cannabis sativa has been linked to the therapeutic management of epilepsy and Tilia × viridis has a tradition of use as a sedative.

This study aimed to evaluate the protective effect of an ethanolic extract of C. sativa (CSRD), an aqueous extract of T. × viridis (TE), and their combination against oxidative stress induced by glutamate in a murine hippocampal neuronal (HT-22) cell line, as well as their anti-inflammatory activity in male Wistar rats’ microglial cells stimulated with LPS.

A phytochemical analysis was also conducted. Glutamate-induced reactive oxygen species (ROS) were quantified using 2′,7′-dichlorodihydrofluorescein diacetate via fluorescence microscopy. Cell viability was assessed using the MTT assay. Distinct microglial cell phenotypes were identified via immunofluorescence.

Extracts partially reversed glutamate-induced loss of cell viability (52% to 200% for CSRD; 22% to 82% for TE). Their combination produced a greater effect, reversing glutamate-induced toxicity by 133% to 284% and fully restoring cell viability to control levels. Moreover, the combined treatment reduced intracellular ROS levels (52% to 58%).

Notably, the combination also exhibited the most pronounced anti-inflammatory effects, significantly reducing the proportion of reactive phenotype 1 cells, while increasing the population of anti-inflammatory phenotype 2 cells and preserving the trophic phenotype 3 subpopulation.

In conclusion, this study not only validates the ethnobotanical uses of C. sativa and T. × viridis but also reveals a potent synergy when combined. This provides a strong foundation for the development of phytomedicines with translational potential for managing complex pathologies like epilepsy or neuroinflammation associated with neurodegenerative diseases.”

https://pubmed.ncbi.nlm.nih.gov/41628619

https://www.thieme-connect.de/products/ejournals/abstract/10.1055/a-2751-0171

Antiseizure Effects of Cannabidiol in Combination With Cannabigerol in the Maximal Electroshock Seizure Model

“Current antiseizure therapy for epilepsy is only effective in about 70% of the patient population.

Previous studies had shown that the addition of small amounts of tetrahydrocannabinol (THC) made cannabidiol (CBD) much more potent in the maximal electroshock seizure (MES) model.

The current study investigated the effects of combining CBD with the non-psychotoxic cannabinoid cannabigerol (CBG) in the MES model in mice.

Mice were administered (i.p.) CBD or CBG or a combination of both before undergoing the MES procedure. Dose-response and dose-toxicity curves were generated for each compound and combinations.

It was found that CBG has antiseizure properties and that it potentiates the effects of CBD.

By using a 1:1 ratio combination of CBD and CBG, the ED50 for CBD was reduced by over 50% and the TD50 for CBD was reduced by 40%, indicating increased toxicity. This suggests that the interaction between CBD and CBG may be additive in nature. Both drugs showed little toxicity at therapeutic doses.

This is the first study to provide detailed dose-response data for CBG as well as CBG in combination with CBD in a seizure model and suggests that the two drugs could act in a similar manner to suppress seizures.”

https://pubmed.ncbi.nlm.nih.gov/41588555

“The present study determines dose–response and dose–toxicity relationships for the non-psychotoxic cannabinoids CBG and CBD in the MES model and finds that CBG has antiseizure effects on its own and can potentiate the antiseizure effects of CBD, possibly in an additive manner. This suggests that CBG and CBD could use similar mechanisms for their antiseizure effects. This study is the first to present antiseizure effects of CBG as well as provide detailed dose–response and dose–toxicity data of CBG in combination with CBD.”

“Cannabinoids have been examined as potential antiseizure drugs but psychotoxic effects and low potency have been problematic. The present study determines dose–response and dose–toxicity relationships for the non‐psychotoxic cannabinoids CBG and CBD in the MES model and finds that CBG has antiseizure effects on its own and can potentiate the antiseizure effects of CBD, possibly in an additive manner. This suggests that CBG and CBD could use similar mechanisms for their antiseizure effects. This study is the first to present antiseizure effects of CBG as well as provide detailed dose–response and dose–toxicity data of CBG in combination with CBD.”

https://onlinelibrary.wiley.com/doi/10.1111/bcpt.70194

Unveiling Neurological Benefits: A Review of Hemp Leaf, Flower, Seed Oil Extract, and Their Phytochemical Properties in Neurological Disorders

“Neurological disorders such as epilepsy, Alzheimer’s disease, Parkinson’s disease, and multiple sclerosis present significant global health care challenges, with complex pathophysiology and limited therapeutic options that often carry substantial side effects.

Hemp-derived compounds, particularly from Cannabis sativa seeds, leaves, and flowers, have gained attention for their potential neuroprotective properties.

This review aims to synthesize the current evidence surrounding the therapeutic benefits of hemp-derived compounds, focusing on their bioactive phytochemical profiles, mechanisms of action, and therapeutic efficacy in treating neurological disorders.

A comprehensive review of pre-clinical and clinical studies was conducted, analyzing the phytochemical composition of hemp extracts, including cannabinoids (such as cannabidiol, CBD), terpenes, flavonoids, and polyunsaturated fatty acids. We explored their mechanisms of action through interactions with the endocannabinoid system, neurotransmitter receptors, inflammatory pathways, and oxidative stress mechanisms.

The review highlights the therapeutic potential of hemp-derived extracts in mitigating various neurological conditions. Pre-clinical and clinical studies have demonstrated their efficacy in reducing seizure frequency in epilepsy, protecting dopaminergic neurons in Parkinson’s disease, alleviating neuroinflammation and oxidative stress in Alzheimer’s disease, and promoting remyelination in multiple sclerosis.

The entourage effect, where cannabinoids, terpenes, and flavonoids work synergistically, enhances these therapeutic effects. Innovations in extraction technologies have optimized yield and preserved bioactivity, further enhancing clinical relevance.

Hemp-derived compounds exhibit significant neuroprotective and therapeutic potential for managing neurological disorders. However, challenges such as product standardization, safety profiles, and regulatory frameworks must be addressed for clinical translation. Further research is essential to optimize dosing, establish safety parameters, and develop standardized formulations, which will be crucial for fully harnessing the therapeutic potential of hemp-derived products in treating neurological conditions.”

https://pubmed.ncbi.nlm.nih.gov/41468178

https://www.liebertpub.com/doi/10.1177/25785125251410822


Medical Cannabis and Epilepsy: The Evidence

“Epilepsy is a serious neurological condition that can affect individuals of all ages. Treatment is far from perfect, and roughly 30% of patients can experience seizures that are resistant to antiseizure medications.

Interestingly, the cannabis plant, specifically the phytocannabinoids, cannabidiol and delta-9-tetrahydrocannabinol, has been shown to possess anticonvulsant properties and are effective in the treatment of seizures.

The clinical evidence base for cannabis for epileptic conditions has been growing in the last few decades with studies aiming to establish the clinical efficacy and safety profile of the plant. Despite the advancements that are being made, clinicians and medical regulatory bodies are still reluctant for epilepsy patients to use cannabis. Thus, it is essential that individuals are educated about the therapeutic properties of cannabis and the clinical evidence base to help patients gain access to cannabis medicines.”

https://pubmed.ncbi.nlm.nih.gov/41284246

“Evidence has shown that the plant possesses a range of therapeutic properties and has suggested its use as a potentially effective treatment for a variety of medical conditions. Consequently, the evidence base for the medicinal use of cannabis has been significantly growing over the years.”

https://www.magonlinelibrary.com/doi/full/10.12968/hmed.2024.0903

A Balanced Cannabinoids Mixture Protects Neural Stem/progenitor Cells from CoCl2 Induced Injury by Regulating Autophagy and Inflammation: An in Vitro Study

“Although tetrahydrocannabinol (THC) and cannabidiol (CBD) have been individually studied for their neuroprotective roles, few studies have addressed the effects of their balanced 1:1 formulation Satinex (STX) under pathologic conditions like hypoxia. Moreover, the effect of STX on embryonic neural stem/progenitor cells (ENS/PCs) derived from the rat embryonic brain, which are highly vulnerable during early development, remains unexplored.

Considering the pivotal role of hypoxia in numerous neuropathological situations, this study examined the impact of STX on rat ENS/PCs exposed to chemically induced hypoxia.

ENS/PCs were isolated from rat embryos and subjected to hypoxia using 100 µM cobalt (II) chloride hexahydrate (CoCl₂0.6 H₂O) for 48 h. Cytotoxic activity of STX andCoCl2was assessed using the 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2 H-tetrazolium (MTT) assay, while stem cell identity was confirmed via flow cytometry (Nestin, SOX2). STX (0.1 and 0.5 µM) was applied under both normoxic and hypoxic conditions. Expression levels of hypoxia-inducible factor 1-alpha (Hif1α) mRNA, autophagy markers (Beclin-1, microtubule-associated protein 1 light chain 3-II [LC3-II]), and pro-inflammatory proteins nuclear factor kappa B [NF-κB], Toll-like receptor 2 [TLR2], Toll-like receptor 4 [TLR4]) were assessed using reverse transcription polymerase chain reaction (RT-PCR) and western blot techniques following STX treatment.

Based on flow cytometric assays, over 70% of cultivated cells were positive for Nestin and SOX2. Hypoxia significantly reduced cell viability and proliferation, accompanied by increased Hif1α mRNA expression. Treatment with STX (0.1 µM and 0.5 µM) significantly reversed these changes, restoring cell viability and proliferation while reducing Hif1α levels. Hypoxia also elevated autophagy markers (Beclin-1, LC3-II) and pro-inflammatory proteins (NF-κB, TLR2, TLR4), which STX suppressed in a dose-dependent manner.

This study provides novel evidence that STX mitigates hypoxia-induced neural damage by downregulating Hif1α and its downstream inflammatory and autophagic signaling pathways. The use of a clinically relevant cannabinoids mixture and a developmentally sensitive cell model underline the translational potential of balanced THC/CBD formulations in the treatment of hypoxia-related neurodegenerative and neurodevelopmental conditions.”

https://pubmed.ncbi.nlm.nih.gov/41240218

https://link.springer.com/article/10.1007/s12640-025-00770-2

Cannabidiol as Adjunctive Treatment in Drug-Resistant Epilepsy With Epileptic Spasms Beyond Two Years of Age

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“Background: To assess the efficacy and safety of adjunctive cannabidiol (CBD) in children with drug-resistant epileptic spasms (ES) beyond age 2 years.

Methods: We conducted a retrospective longitudinal study of patients with childhood epileptic spasms (CESs) treated with purified CBD (Epidyolex) at Niño Jesus Hospital in Madrid, Spain, from 2020 to 2024. All patients were older than 2 years and had drug-resistant epilepsy and ES as the primary seizure type. Efficacy was assessed by comparing ES frequency before and after CBD treatment, with a good response defined as a ≥50% reduction in ES. Adverse effects (AEs) were recorded to assess safety and tolerability.

Results: Of the 53 patients included, 58.5% achieved a ≥50% reduction in ES frequency, 15% of whom attained complete freedom from ES. Patients with malformations of cortical development and Down syndrome showed the highest response rates. Clobazam was the most frequently associated medication (77.3%), indicating a potential synergistic effect. AEs were reported in 62.2% of patients, with drowsiness, hyperammonemia, and behavioral disturbances being the most common. CBD was discontinued in 17% due to lack of efficacy and in 11.3% due to AEs.

Conclusions: CBD appears to be an effective and well-tolerated adjunctive treatment for drug-resistant ES in children older than 2 years. Significant response rates were found, particularly in patients with Down syndrome and malformations of cortical development. Future studies with larger cohorts and longer follow-up are needed to validate these findings and explore the potential for earlier use of CBD in treatment-resistant epilepsy.”

https://pubmed.ncbi.nlm.nih.gov/41197417/

https://www.pedneur.com/article/S0887-8994(25)00314-5/abstract

Real-world efficacy and safety of cannabidiol in developmental and epileptic encephalopathies

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“Objective: Highly purified cannabidiol (CBD) is approved as adjunctive therapy for seizures associated with Dravet syndrome (DS), Lennox-Gastaut syndrome (LGS), and tuberous sclerosis complex (TSC), although its role in other developmental and epileptic encephalopathies (DEEs) remains unexplored. The aim of this study was to assess the real-world use, efficacy, and safety of CBD across a broad cohort of patients with DEEs, including off-label indications.

Methods: In this retrospective study, we evaluated 107 patients with DEEs treated with CBD for ≥3 months between 2020 and 2024. Data on seizure frequency, tolerability, retention, and non-seizure outcomes were collected. Efficacy was defined as ≥50% or ≥75% seizure reduction. Statistical analyses explored predictors of response.

Results: Patients had LGS (55.1%), DS (16.8%), TSC (8.4%), or other DEEs (19.6%), with a genetic etiology in 56.1%. At a median follow-up of 20 months, 69% achieved ≥50% seizure reduction, and 21% achieved ≥75% reduction. Patients with LGS, TSC, and other DEEs showed higher efficacy and retention rates compared to DS. Genetic or unknown etiology was associated with better outcomes (p = 0.011). Combination with valproate was associated with reduced efficacy (p = 0.006), while combination with clobazam had no significant effect on efficacy nor safety. Non-seizure improvements included increased alertness (56%), improved sleep quality (25%), and enhanced motor performance (14%). Adverse events occurred in 33.6%, mostly mild and transient; 9% discontinued due to side effects.

Significances: This study confirms the effectiveness and good tolerability of CBD in a real-world DEE population, including off-label use. These findings support expanding CBD indications and underscore the need for prospective studies targeting both seizure and developmental outcomes.

Plain language summary: This study looked at the use of cannabidiol (CBD), a cannabis-based medicine, in 107 people with severe forms of epilepsy called developmental and epileptic encephalopathies (DEEs). With CBD add-on, about two-thirds of patients had fewer seizures, and some caregivers noticed improvements in alertness, sleep, or movement. Most patients tolerated the treatment well, but some experienced side effects, and a few had to stop taking it. While the results are promising, more research is needed to confirm how effective and safe CBD is for different types of DEEs, especially those not currently approved for treatment with CBD.”

https://pubmed.ncbi.nlm.nih.gov/41165013/

“After a median follow-up of 20 months, CBD was globally effective and safe in 107 patients with LGS, DS, TSC, and other DEEs.”

https://onlinelibrary.wiley.com/doi/10.1002/epi4.70149

Efficacy and safety of cannabidiol in children with developmental and epileptic encephalopathies: A systematic review

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“Background: Developmental and epileptic encephalopathies (DEEs) constitute rare epileptic conditions characterized by treatment-resistant seizures, neurodevelopmental delay, and various comorbidities. None of the currently available drugs have proven effective in suppressing epileptiform activity in those conditions.

Objectives: We aimed to assess the efficacy and safety of cannabidiol in children with DEEs through a systematic review.

Methods: We searched MEDLINE, Cochrane Central Register of Controlled Trials, trial registries, and reference lists of included studies. We conducted the last search on March 9, 2024. All study types investigating pharmaceutical cannabidiol in children with DEEs were considered eligible, with no language or date restrictions. Risk of bias was assessed using RoB2 and ROBINS-I V2.

Results: Of the 722 records identified, 14 met the inclusion criteria. The included studies varied in design and involved a total of 682 children. Cannabidiol was administered to a maximum dose of 50mg/kg/day. Almost all studies reported positive outcomes with cannabidiol, leading to a reduction of a 50% or above in seizure frequency in at least 20% of patients included in 11 studies. Adverse events were relatively common across studies and included somnolence, loss of appetite, diarrhea, fatigue, and increased serum aminotransferases. Most of them were mild to moderate and reversible.

Conclusions: Cannabidiol is generally well tolerated and has been shown to effectively reduce seizure frequency in children with DEEs whose seizures are refractory to concomitant antiepileptic medications. Future research should explore the long-term effects of cannabidiol on seizure control, developmental outcomes, and quality of life in this population.”

https://pubmed.ncbi.nlm.nih.gov/41135306/

https://www.seizure-journal.com/article/S1059-1311(25)00269-9/abstract

Molecular targets of cannabinoids and their derivatives in epilepsy – a review with focus on CBD

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“In recent years, cannabinoids and their derivatives have been tested for efficacy in epilepsy therapy and related disorders. Many of them may help alleviate ailments associated with seizures. An in-depth study of cannabinoid derivatives and the receptors on which they operate give us a chance for more effective use of these substances in epilepsy therapy.

Many studies point to the beneficial synergy of cannabinoids with chemotherapeutics and the increase in effectiveness of the latter. As a result, both alternatives to drug treatment and support for the pharmacotherapy are being developed.

In this review, we focused on compounds such as Δ9-THC, CBDV, Δ9-THCA, Δ9-THCV, H2CBD and their receptors as well as on CBD’s actions, and the enzymes, ion channels, and transporters engaged in the fundamental causes of epileptic seizures.

Treating epilepsy and drug-resistant epilepsy are the two common medical uses of cannabinoids. We looked at approximately 150 current scientific articles from peer-reviewed journals to explore the molecular effects of cannabinoids in these applications. Our goal was to improve physician awareness of factors influencing treatment decisions and potential adverse reactions to minimize medical errors and optimize patient care.”

https://pubmed.ncbi.nlm.nih.gov/41098593/

“In conclusion, while CBD now stands as a recognized and effective treatment for specific forms of epilepsy, a deeper, integrated understanding of its comprehensive mechanisms, validated efficacy across diverse populations, and long-term safety profile remains essential. Continued collaborative efforts among scientists, clinicians, and policymakers, coupled with stringent critical appraisal of evidence, will be key to unlocking the full and safe potential of cannabinoids in epilepsy therapy.”

https://www.frontierspartnerships.org/journals/acta-biochimica-polonica/articles/10.3389/abp.2025.15251/full