Curcumin in epilepsy disorders

Identification of Curcumin Targets in the Brain of Epileptic Mice Using DARTS

Curcumin, a compound derived from turmeric, is traditionally utilized in East Asian medicine for treating various health conditions, including epilepsy. Despite its involvement in numerous cellular signaling pathways, the specific mechanisms and targets of curcumin in epilepsy treatment have remained unclear. Our study focused on identifying the primary targets and functional pathways of curcumin in the brains of epileptic mice. Using drug affinity responsive target stabilization (DARTS) and affinity chromatography, we identified key targets in the mouse brain, revealing 232 and 70 potential curcumin targets, respectively. Bioinformatics analysis revealed a strong association of these proteins with focal adhesions and cytoskeletal components. Further experiments using DARTS, along with immunofluorescence staining and cell migration assays, confirmed curcumin's ability to regulate the dynamics of focal adhesions and influence cell migration. This study not only advances our understanding of curcumin's role in epilepsy treatment but also serves as a model for identifying therapeutic targets in neurological disorders.

Curcumin Lowers the Accelerated Speed of Epileptogenesis by Traumatic Brain Injury

Background

Traumatic brain injury or TBI can underlie epilepsy. Prevention of PTE has been of great interest to scientists. Given the antiepileptic, antioxidant and anti-inflammatory activities of curcumin, we examined whether this compound can affect epileptogenesis in rats after TBI.

Methods

Curcumin was injected once a day for two weeks. TBI was induced in the temporal cortex of anesthetized rats using a controlled cortical impact device. One day after TBI, pentylenetetrazole (PTZ), 35 mg/kg, was injected i.p. every other day until manifestation of generalized seizures. The number of PTZ injections was then recorded. Moreover, the extent of cortical and hippocampal IL-1β and glial fibrillary acidic protein (GFAP) expression in the epileptic rats were measured by Western blot analysis.

Results

Curcumin 50 and 150 mg/kg prevented the development of kindling, whereas TBI accelerated the rate of kindling. Curcumin 20 mg/kg prohibited kindling facilitation by TBI, and reduced the expression of IL-1β and GFAP induced by TBI.

Conclusion

Curcumin can stop the acceleration of epileptogenesis after TBI in rats. Inhibiting hippocampal and cortical overexpression of IL-1β and GFAP seems to be involved in this activity.

Zebrafish as a robust preclinical platform for screening plant-derived drugs with anticonvulsant properties-a review

Traditionally, selected plant sources have been explored for medicines to treat convulsions. This continues today, especially in countries with low-income rates and poor medical systems. However, in the low-income countries, plant extracts and isolated drugs are in high demand due to their good safety profiles. Preclinical studies on animal models of seizures/epilepsy have revealed the anticonvulsant and/or antiepileptogenic properties of, at least some, herb preparations or plant metabolites. Still, there is a significant number of plants known in traditional medicine that exert anticonvulsant activity but have not been evaluated on animal models. Zebrafish is recognized as a suitable in vivo model of epilepsy research and is increasingly used as a screening platform. In this review, the results of selected preclinical studies are summarized to provide credible information for the future development of effective screening methods for plant-derived antiseizure/antiepileptic therapeutics using zebrafish models. We compared zebrafish vs. rodent data to show the translational value of the former in epilepsy research. We also surveyed caveats in methodology. Finally, we proposed a pipeline for screening new anticonvulsant plant-derived drugs in zebrafish ("from tank to bedside and back again").

PET Imaging and Neurohistochemistry Reveal that Curcumin Attenuates Brain Hypometabolism and Hippocampal Damage Induced by Status Epilepticus in Rats

Numerous preclinical studies provide evidence that curcumin, a polyphenolic phytochemical extracted from Curcuma longa (turmeric) has neuroprotective, anti-inflammatory and antioxidant properties against various neurological disorders. Curcumin neuroprotective effects have been reported in different animal models of epilepsy, but its potential effect attenuating brain glucose hypometabolism, considered as an early marker of epileptogenesis that occurs during the silent period following status epilepticus (SE), still has not been addressed. To this end, we used the lithium-pilocarpine rat model to induce SE. Curcumin was administered orally (300 mg/kg/day, for 17 days). Brain glucose metabolism was evaluated in vivo by 2-deoxy-2-[¹⁸F]Fluoro-D-Glucose ([¹⁸F]FDG) positron emission tomography (PET). In addition, hippocampal integrity, neurodegeneration, microglia-mediated neuroinflammation, and reactive astrogliosis were evaluated as markers of brain damage. SE resulted in brain glucose hypometabolism accompanied by body weight (BW) loss, hippocampal neuronal damage, and neuroinflammation. Curcumin did not reduce the latency time to the SE onset, nor the mortality rate associated with SE. Nevertheless, it reduced the number of seizures, and in the surviving rats, curcumin protected BW and attenuated the short-term glucose brain hypometabolism as well as the signs of neuronal damage and neuroinflammation induced by the SE. Overall, our results support the potential adaptogen-like effects of curcumin attenuating key features of SE-induced brain damage.

Curcumin-loaded hydroxypropyl-β-cyclodextrin inclusion complex with enhanced dissolution and oral bioavailability for epilepsy treatment

Curcumin, the main bioactive component of turmeric, has a wild range of beneficial effects on central nervous diseases, including anti-Alzheimer's disease, antioxidant stress, and anti-inflammation. Currently, it has been demonstrated the anti-epileptic potential. However, curcumin has poor water solubility, high sensitivity to light and heat, and low absorption, which results in low bioavailability and greatly limits the clinical application of curcumin, as well as the elusive effects in anti-epileptic treatment.This study aimed to develop a curcumin hydroxypropyl-β-cyclodextrin inclusion complex (CUR-HP-β-CD) to improve its bioavailability and facilitate its potential development as an anti-epileptic drug. The CUR-HP-β-CD was generated by the solvent evaporation method, which has efficient entrapment, high solubility, and facilitated bioavailability and brain distribution.The solubility of the CUR-HP-β-CD was 63.5, 60.1, and 52.9 times that of the unformulated curcumin in H₂O, HCl (pH 1.2), and PBS (pH 6.8), respectively. The bioavailability of CUR-HP-β-CD is improved 2.8 times and 38.7 folds higher brain concentrations. Moreover, the therapeutic anti-epileptic effects of CUR-HP-β-CD were much more effective in pentylenetetrazol (PTZ)-induced zebrafish and mouse models.This study showed a simple and reproducible strategy to effectively improve the bioavailability and therapeutic effects of curcumin, which could be potentially used in epilepsy treatment.

Mechanisms Underlying Curcumin-Induced Neuroprotection in Cerebral Ischemia

Ischemic stroke is the leading cause of death and disability worldwide, and restoring the blood flow to ischemic brain tissues is currently the main therapeutic strategy. However, reperfusion after brain ischemia leads to excessive reactive oxygen species production, inflammatory cell recruitment, the release of inflammatory mediators, cell death, mitochondrial dysfunction, endoplasmic reticulum stress, and blood–brain barrier damage; these pathological mechanisms will further aggravate brain tissue injury, ultimately affecting the recovery of neurological functions. It has attracted the attention of researchers to develop drugs with multitarget intervention effects for individuals with cerebral ischemia. A large number of studies have established that curcumin plays a significant neuroprotective role in cerebral ischemia via various mechanisms, including antioxidation, anti-inflammation, anti-apoptosis, protection of the blood–brain barrier, and restoration of mitochondrial function and structure, restoring cerebral circulation, reducing infarct volume, improving brain edema, promoting blood–brain barrier repair, and improving the neurological functions. Therefore, summarizing the results from the latest literature and identifying the potential mechanisms of action of curcumin in cerebral ischemia will serve as a basis and guidance for the clinical applications of curcumin in the future.

The Interconnected Mechanisms of Oxidative Stress and Neuroinflammation in Epilepsy

One of the most important characteristics of the brain compared to other organs is its elevated metabolic demand. Consequently, neurons consume high quantities of oxygen, generating significant amounts of reactive oxygen species (ROS) as a by-product. These potentially toxic molecules cause oxidative stress (OS) and are associated with many disorders of the nervous system, where pathological processes such as aberrant protein oxidation can ultimately lead to cellular dysfunction and death. Epilepsy, characterized by a long-term predisposition to epileptic seizures, is one of the most common of the neurological disorders associated with OS. Evidence shows that increased neuronal excitability—the hallmark of epilepsy—is accompanied by neuroinflammation and an excessive production of ROS; together, these factors are likely key features of seizure initiation and propagation. This review discusses the role of OS in epilepsy, its connection to neuroinflammation and the impact on synaptic function. Considering that the pharmacological treatment options for epilepsy are limited by the heterogeneity of these disorders, we also introduce the latest advances in anti-epileptic drugs (AEDs) and how they interact with OS. We conclude that OS is intertwined with numerous physiological and molecular mechanisms in epilepsy, although a causal relationship is yet to be established.

Neuroprotective Effects of Thymoquinone by the Modulation of ER Stress and Apoptotic Pathway in In Vitro Model of Excitotoxicity

Experimental evidence indicates that the activation of ionotropic glutamate receptors plays an important role in neurological disorders’ models such as epilepsy, cerebral ischemia and trauma. The glutamate receptor agonist kainic acid (KA) induces seizures and excitotoxic cell death in the CA3 region of the hippocampus. Thymoquinone (TQ) is the most important component of the essential oil obtained from black cumin (Nigella sativa L.) seeds. It has many pharmacological actions including antioxidant, anti-inflammatory, and anti-apoptotic effects. TQ was used in an in vitro experimental model of primary cultures where excitotoxicity was induced. Briefly, rat organotypic hippocampal slices were exposed to 5 µM KA for 24 h. Cell death in the CA3 subregions of slices was quantified by measuring propidium iodide fluorescence. The cross-talk between TQ, ER stress and apoptotic pathways was investigated by Western blot. In untreated slices TQ (10 µM) induced a significant increase on the PSD95 levels and it decreased the excitotoxic injury induced by KA. Additionally, TQ was able to ameliorate the KA-induced increase in unfolded proteins GRP78 and GRP94 expression. Finally, TQ was able to partially rescue the reduction of the KA-induced apoptotic pathway activation. Our results suggest that TQ modulates the processes leading to post-kainate neuronal death in the CA3 hippocampal area.

Enlightening the neuroprotective effect of quercetin in epilepsy: From mechanism to therapeutic opportunities

Epilepsy is a devastating neurological disorder characterized by the repeated occurrence of epileptic seizures. Epilepsy stands as a global health concern affecting around 70 million people worldwide. The mainstream antiepileptic drugs (AEDs) only exert symptomatic relief and drug-resistant epilepsy occurs in up to 33 percent of patients. Hence, the investigation of novel therapeutic strategies against epileptic seizures that could exert disease modifying effects is of paramount importance. In this context, compounds of natural origin with potential antiepileptic properties have recently gained increasing attention. Quercetin is a plant-derived flavonoid with several pharmacological activities. Emerging evidence has demonstrated the antiepileptic potential of quercetin as well. Herein, based on the available evidence, we discuss the neuroprotective effects of quercetin against epileptic seizures and further analyze the plausible underlying molecular mechanisms. Our review suggests that quercetin might be a potential therapeutic candidate against epilepsy that deserves further investigation, and paves the way for the development of plant-derived antiepileptic treatment approaches.

Luminescence of Eu (III) complex under near-infrared light excitation for curcumin detection

An intrinsic Eu(III) luminescence phenomenon of Eu(III) complex was found under near-infrared light (NIRL) excitation of xenon lamp, and the maximum excitation wavelength is about twice the excitation wavelength of its Stokes fluorescence. The NIRL excitation fluorescence was mainly originated from second order diffracted light (SODL) excitation. The Eu(III) complex was consist of Eu(III), Gd(III), 2-trifluoroacetylacetone (TTA) and cetyltrimethylammonium bromide (CTAB). Curcumin (Cur) could notably quench the luminescence intensity of the Eu(III) complex. Based on this, a sensitive method for Cur detection was developed. Under optimum conditions, the decrease extent in the fluorescence intensity at 611 nm exhibited a good linear relationship with the Cur concentration in the range of 2.0 × 10^-9 mol/L - 6.0 × 10^-8 mol/L under 746 nm excitation, the limit of detection (LOD, S/N = 3) was 5.2 × 10^-10 mol/L. While, the linear relationship and the LOD of Stokes fluorescence method (λ_ex/λ_em = 360/611 nm) were found to be 1.0 × 10^-8 mol/L - 6.0 × 10^-8 mol/L and 2.6 × 10^-9 mol/L, respectively. The former method is superior to the latter one in Cur detection. Both two methods were successfully applied to determine Cur in real samples. The luminescence mechanism of Eu(III) complex under the NIRL excitation and the quenching mechanism of Cur on the Eu(III) fluorescence was also investigated.

Therapeutic effects of curcumin on sepsis and mechanisms of action: A systematic review of preclinical studies

Sepsis is a complex disease that begins with an infectious disorder and causes excessive immune responses. Curcumin is considered as an active component of turmeric that can improve the condition in sepsis due to its anti-inflammatory and antioxidant properties. PubMed, Embase, Google Scholar, Web of Science, and Scopus databases were searched. Searching was not limited to a specific publication period. Only English-language original articles, which had examined the effect of curcumin on sepsis, were included. At first, 1,098 articles were totally found, and 209 articles were selected after excluding duplicated data; 46 articles were remained due to the curcumin effects on sepsis. These included 23 in vitro studies and 23 animal studies. Our results showed that curcumin and various analogs of curcumin can have an inhibitory effect on sepsis-induced complications. Curcumin has the ability to inhibit the inflammatory, oxidative coagulation factors, and regulation of immune responses in sepsis. Despite the promising evidence of the therapeutic effects of curcumin on the sepsis complication, further studies seem necessary to investigate its effect and possible mechanisms of action in human studies.

Curcumin-loaded nanoparticles: a novel therapeutic strategy in treatment of central nervous system disorders

Curcumin as a hydrophobic polyphenol is extracted from the rhizome of Curcuma longa. Curcumin is widely used as a dietary spice and a topical medication for the treatment of inflammatory disorders in Asia. This compound also possesses remarkable anti-inflammatory and neuroprotective effects with the ability to pass from the blood brain barrier. Based on several pharmacological activities of curcumin, it has been introduced as an ideal candidate for different neurological disorders. Despite the pleiotropic activities of curcumin, poor solubility, rapid clearance and low stability have limited its clinical application. In recent years, nano-based drug delivery system has effectively improved the aqueous solubility and bioavailability of curcumin. In this review article, the effects of curcumin nanoparticles and their possible mechanism/s of action has been elucidated in various central nervous system (CNS)-related diseases including Parkinson's disease, Huntington disease, Alzheimer's disease, Multiple sclerosis, epilepsy and Amyotrophic Lateral Sclerosis. Furthermore, recent evidences about administration of nano-curcumin in the clinical trial phase have been described in the present review article.

Preparation, Characterization, and Release Kinetics of Chitosan-Coated Nanoliposomes Encapsulating Curcumin in Simulated Environments

Curcumin, a natural polyphenol, has many biological properties, such as anti-inflammatory, antioxidant, and anti-carcinogenic properties, yet, its sensitivity to light, oxygen, and heat, and its low solubility in water renders its preservation and bioavailability challenging. To increase its bioaccessibility, we fabricated nanoliposomes and chitosan-coated nanoliposomes encapsulating curcumin, and we evaluated the systems in terms of their physicochemical characteristics and release profiles in simulated gastrointestinal mediums. Chitosan-coating enhanced the stability of nanoliposomes and slowed the release of curcumin in the simulated gastrointestinal (GI) environment. This study demonstrates that nanoliposomes and chitosan-coated nanoliposomes are promising carriers for poorly soluble lipophilic compounds with low oral bioavailability, such as curcumin.