Is the antiparasitic drug ivermectin a suitable candidate for the treatment of epilepsy?

Community-based epilepsy care in an onchocerciasis-endemic area: A 3-year cohort study in Mahenge, Tanzania

OBJECTIVE

In onchocerciasis-endemic areas, limited access to antiseizure medications (ASMs) contributes to a high epilepsy burden. This study evaluated the impact of a community-based epilepsy care program in Mahenge, Tanzania, an onchocerciasis-endemic area with high epilepsy prevalence.

METHODS

A baseline survey (2017-2018) identified persons with epilepsy (PWE) in four rural villages. Subsequently, PWE were invited to enroll in the epilepsy treatment program (2019-2022), where trained community health workers (CHWs) screened for epilepsy, promoted ivermectin intake to treat onchocerciasis, distributed ASMs, and monitored seizure frequency and ASM adherence monthly under supervision from the project clinician trained in epilepsy diagnosis and treatment. A concluding survey (2022) collected sociodemographic data and participants' status as alive, deceased, or lost to follow-up. Mixed-effects negative binomial regression analyzed risk factors for weekly seizure incidence rate.

RESULTS

Of 206 participants, 77.7% reported bilateral tonic-clonic seizures, and 32.0% reported focal seizures. More than one third (38.5%) were suspected of having nodding syndrome. Weekly seizure frequency decreased significantly from a mean of 1.9 seizures (interquartile range [IQR] = 0-2) at enrollment to .4 seizures (IQR = 0-0) at the last follow-up (Wilcoxon test p < .0001), with significantly improved ASM adherence (57.5%-94.7%, McNemar test p < .0001). Factors associated with lower weekly seizure incidence included longer program participation, ASM adherence, carbamazepine use compared to phenobarbital, and ivermectin intake in 2022. ASM adverse events were associated with increased seizure frequency. The mortality rate was 32.7 deaths per 1000 person-years, with most deceased not fully adhering to ASM (88%) and having epilepsy-related causes of death (60%).

SIGNIFICANCE

The community-based program using CHWs was associated with a significant reduction in seizure frequency and improved ASM adherence. In onchocerciasis-endemic areas, it should be investigated whether carbamazepine should be a preferred ASM in PWE. Ivermectin's impact on seizure frequency merits further investigation in onchocerciasis-endemic areas. Community-based epilepsy care is a promising strategy for scaling up epilepsy care in rural areas in Africa.

Ivermectin as a promising therapeutic option for onchocerciasis-associated epilepsy

Onchocerciasis, commonly known as river blindness, is a neglected tropical disease caused by the parasite Onchocerca volvulus. It can lead to blindness and visual impairment. Studies have also demonstrated a link between onchocerciasis and epilepsy, with there being a correlation between onchocerciasis endemicity and epilepsy prevalence. Onchocerciasis-associated epilepsy (OAE) emerges predominantly in individuals aged 3-18, with a notable prevalence in regions where onchocerciasis transmission persists. These areas exhibit elevated rates of epilepsy, underscoring the significant impact of ongoing onchocerciasis on the incidence of epilepsy, particularly within the specified age range. Both epilepsy prevalence and incidence have evolved over the past three decades in a Tanzanian area endemic for onchocerciasis. Researchers have studied the effects of the antiparasitic drug ivermectin on OAE. About one third of Ugandan patients saw reduced seizure frequency or intensity after one 150 μg/kg dose. Clinical research in the Congo among infected epileptics on anti-seizure medications (ASMs) suggested ivermectin may decrease seizure frequency following oral administration of ivermectin tablets (3 mg). Beyond its antiparasitic properties, ivermectin has demonstrated anticonvulsant effects against clonic and tonic-clonic seizures, likely through modulation of GABAA receptor and neuroinflammation. There is evidence of synergistic effects when combined with GABAergic ASMs like diazepam. As neuroinflammation plays a key role in OAE, ivermectin's anti-inflammatory properties by inhibiting cytokines like TNF-α and IL-1β are also relevant. While certain other antiparasitic drugs can interact with ASMs and have side effects like seizures, no such interactions or side effects have been reported for ivermectin. However, there is a need for more randomized controlled trials specifically evaluating ivermectin's impact on seizures in O. volvulus-infected epileptics on ASMs. Given its efficacy against parasites, limited side effects, and potential anticonvulsant mechanisms, ivermectin could be a favorable first-line treatment option, but further research is warranted to confirm benefits for OAE. PLAIN LANGUAGE SUMMARY: This article explores the potential benefits of ivermectin, a drug commonly used to treat parasitic infections, for reducing seizures in people with epilepsy linked to onchocerciasis, also known as river blindness. Research shows that ivermectin not only targets the parasitic cause of the disease but may also help reduce brain inflammation, which plays a key role in epilepsy. While early results are promising, more research is needed to confirm whether ivermectin can be a reliable treatment for epilepsy in people affected by this condition.

Modulation of GABAergic neurons in acute epilepsy using sonogenetics

Epilepsy, a neurological disorder caused by hypersynchronous neural disturbances, has traditionally been treated with surgery, pharmacotherapy, and neuromodulation techniques such as deep brain stimulation and vagus nerve stimulation. However, these methods are often limited by invasiveness, off-target effects, and poor resolution. We present a noninvasive alternative utilizing sonogenetics to selectively stimulate γ-aminobutyric acid (GABA)ergic neurons in the amygdala through engineered auditory-sensing protein, mPrestin (N7T, N308S), in a pentylenetetrazole-induced rat model. Activation of GABAergic neurons induced by the sonication with 0.5-MHz transcranial ultrasound can modulate epileptiform activity by 50 %. Electrophysiological recordings confirmed effective neuromodulation and persistent seizure suppression up to 60 min post-treatment without tissue damage, inflammation, or apoptosis. This sonogenetic approach offers a promising, safe method for epilepsy management by targeting GABAergic neurons.

Importin subunit beta-1 mediates ERK5 nuclear translocation, and its inhibition synergizes with ERK5 kinase inhibitors in reducing cancer cell proliferation

The mitogen-activated protein kinase (MAPK) extracellular signal-regulated kinase 5 (ERK5) is emerging as a promising target in cancer. Indeed, alterations of the MEK5/ERK5 pathway are present in many types of cancer, including melanoma. One of the key events in MAPK signalling is MAPK nuclear translocation and its subsequent regulation of gene expression. Likewise, the effects of ERK5 in supporting cancer cell proliferation have been linked to its nuclear localization. Despite many processes regulating ERK5 nuclear translocation having been determined, the nuclear transporters involved have not yet been identified. Here, we investigated the role of importin subunit alpha (α importin) and importin subunit beta-1 (importin β1) in ERK5 nuclear shuttling to identify additional targets for cancer treatment. Either importin β1 knockdown or the α/β1 importin inhibitor ivermectin reduced the nuclear amount of overexpressed and endogenous ERK5 in HEK293T and A375 melanoma cells, respectively. These results were confirmed in single-molecule microscopy in HeLa cells. Moreover, immunofluorescence analysis showed that ivermectin impairs epidermal growth factor (EGF)-induced ERK5 nuclear shuttling in HeLa cells. Both co-immunoprecipitation experiments and proximity ligation assay provided evidence that ERK5 and importin β1 interact and that this interaction is further induced by EGF administration and prevented by ivermectin treatment. The combination of ivermectin and the ERK5 inhibitor AX15836 synergistically reduced cell viability and colony formation ability in A375 and HeLa cells and was more effective than single treatments in preventing the growth of A375 and HeLa spheroids. The increased reduction of cell viability upon the same combination was also observed in patient-derived metastatic melanoma cells. The combination of ivermectin and ERK5 inhibitors other than AX15836 provided similar effects on cell viability. The identification of importin β1 as the nuclear transporter of ERK5 may be exploited for additional ERK5-inhibiting strategies for cancer therapy.

Ivermectin Exerts Anticonvulsant Effects Against Status Epilepticus Induced by Lithium-Pilocarpine in Rats via GABAA Receptor and Neuroinflammation Modulation: Possible Interaction of Opioidergic Pathways and KATP Channel with Nitrergic System

Status epilepticus (SE) is a critical medical emergency marked by persistent or rapidly repeating seizures, posing a threat to life. Using the lithium-pilocarpine-induced SE model, we decide to evaluate the anti-seizure effects of ivermectin as a positive allosteric modulator of GABAA receptor and the underlying mechanisms involved. Lithium chloride was injected intraperitoneally at a dose of 127 mg/kg, followed by the administration of pilocarpine at a dose of 60 mg/kg after a 20-h interval in order to induce SE. Subsequently, the rats received varying amounts of ivermectin (0.3, 1, 3, 5, and 10 mg/kg, i.p.) 30 min before the onset of SE. To study the underlying molecular mechanisms, we had pharmacological interventions of diazepam (1 mg/kg), glibenclamide and nicorandil as ATP-sensitive potassium channel blocker and opener (both 1 mg/kg, i.p.), naltrexone and morphine, as opioid receptor antagonist and agonist (1 mg/kg and 0.5 mg/kg, i.p., respectively). In addition, three nitric oxide inhibitors, namely, L-NAME (10 mg/kg, i.p.), 7-NI (30 mg/kg, i.p.), and aminoguanidine (100 mg/kg, i.p.), were administered to the rats in the experiment. Finally, we use ELISA and western blotting, respectively, to examine the amounts of pro-inflammatory cytokines (TNF-α and IL-1β), nitrite, and GABAA receptors in the rat hippocampal tissue. The study found that ivermectin, at doses of 3, 5, and 10 mg/kg, exerts anti-seizure effects and decrease Racine's scale SE score. Interestingly glibenclamide and naltrexone reduced the anti-seizure effects of ivermectin, and from other hand diazepam, nicorandil, morphine, L-NAME, 7-NI, and aminoguanidine, enhance the effects when co-administrated with subeffective dose of ivermectin. Additionally, the study found that ivermectin decreased the elevated levels of TNF-α and IL-1β following SE, while increased the reduced expression of GABAA receptors. Overall, these findings suggest that ivermectin has anti-seizure effects in a SE seizure which may be mediated by the modulation of GABAergic, opioidergic, and nitrergic pathways and KATP channels.

Ivermectin Synergizes with Modulated Electro-hyperthermia and Improves Its Anticancer Effects in a Triple-Negative Breast Cancer Mouse Model

Triple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype, with limited treatment options. Modulated electro-hyperthermia (mEHT) is a novel adjuvant cancer therapy that induces selective cancer damage. However, mEHT upregulates heat shock protein beta 1 (HSPB1), a cancer-promoting stress chaperone molecule. Thus, we investigated whether ivermectin (IVM), an anthelmintic drug, may synergize with mEHT and enhance its anticancer effects by inhibiting HSPB1 phosphorylation. Isogenic 4T1 TNBC cells were inoculated into BALB/c mice and treated with mEHT, IVM, or a combination of both. IVM synergistically improved the tumor growth inhibition achieved by mEHT. Moreover, IVM downregulated mEHT-induced HSPB1 phosphorylation. Thus, the strongest cancer tissue damage was observed in the mEHT + IVM-treated tumors, coupled with the strongest apoptosis induction and proliferation inhibition. In addition, there was no significant body weight loss in mice treated with mEHT and IVM, indicating that this combination was well-tolerated. In conclusion, mEHT combined with IVM is a new, effective, and safe option for the treatment of TNBC.

Improving the treatment of bacterial infections caused by multidrug-resistant bacteria through drug repositioning

Drug repurposing (repositioning) is a dynamically-developing area in the search for effective therapy of infectious diseases. Repositioning existing drugs with a well-known pharmacological and toxicological profile is an attractive method for quickly discovering new therapeutic indications. The off-label use of drugs for infectious diseases requires much less capital and time, and can hasten progress in the development of new antimicrobial drugs, including antibiotics. The use of drug repositioning in searching for new therapeutic options has brought promising results for many viral infectious diseases, such as Ebola, ZIKA, Dengue, and HCV. This review describes the most favorable results for repositioned drugs for the treatment of bacterial infections. It comprises publications from various databases including PubMed and Web of Science published from 2015 to 2023. The following search keywords/strings were used: drug repositioning and/or repurposing and/or antibacterial activity and/or infectious diseases. Treatment options for infections caused by multidrug-resistant bacteria were taken into account, including methicillin-resistant staphylococci, multidrug-resistant Mycobacterium tuberculosis, or carbapenem-resistant bacteria from the Enterobacteriaceae family. It analyses the safety profiles of the included drugs and their synergistic combinations with antibiotics and discusses the potential of antibacterial drugs with antiparasitic, anticancer, antipsychotic effects, and those used in metabolic diseases. Drug repositioning may be an effective response to public health threats related to the spread of multidrug-resistant bacterial strains and the growing antibiotic resistance of microorganisms.

New GABA-Targeting Therapies for the Treatment of Seizures and Epilepsy: II. Treatments in Clinical Development

The inhibitory neurotransmitter γ-aminobutyric acid (GABA) plays an important role in the modulation of neuronal excitability, and a disruption of GABAergic transmission contributes to the pathogenesis of some seizure disorders. Although many currently available antiseizure medications do act at least in part by potentiating GABAergic transmission, there is an opportunity for further research aimed at developing more innovative GABA-targeting therapies. The present article summarises available evidence on a number of such treatments in clinical development. These can be broadly divided into three groups. The first group consists of positive allosteric modulators of GABAA receptors and includes Staccato® alprazolam (an already marketed benzodiazepine being repurposed in epilepsy as a potential rescue inhalation treatment for prolonged and repetitive seizures), the α2/3/5 subtype-selective agents darigabat and ENX-101, and the orally active neurosteroids ETX155 and LPCN 2101. A second group comprises two drugs already marketed for non-neurological indications, which could be repurposed as treatments for seizure disorders. These include bumetanide, a diuretic agent that has undergone clinical trials in phenobarbital-resistant neonatal seizures and for which the rationale for further development in this indication is under debate, and ivermectin, an antiparasitic drug currently investigated in a randomised double-blind trial in focal epilepsy. The last group comprises a series of highly innovative therapies, namely GABAergic interneurons (NRTX-001) delivered via stereotactic cerebral implantation as a treatment for mesial temporal lobe epilepsy, an antisense oligonucleotide (STK-001) aimed at upregulating NaV1.1 currents and restoring the function of GABAergic interneurons, currently tested in a trial in patients with Dravet syndrome, and an adenoviral vector-based gene therapy (ETX-101) scheduled for investigation in Dravet syndrome. Another agent, a subcutaneously administered neuroactive peptide (NRP2945) that reportedly upregulates the expression of GABAA receptor α and β subunits is being investigated, with Lennox-Gastaut syndrome and other epilepsies as proposed indications. The diversity of the current pipeline underscores a strong interest in the GABA system as a target for new treatment development in epilepsy. To date, limited clinical data are available for these investigational treatments and further studies are required to assess their potential value in addressing unmet needs in epilepsy management.