The Neuroprotective Role of Origanum syriacum L. and Lavandula dentata L. Essential Oils through Their Effects on AMPA Receptors

Phytochemical analysis, antibacterial and antifungal effect of Lavandula dentata L. essential oil and methanol extract

The aim of this study was to analyse the essential oil of Lavandula dentata from Algeria and to test the antioxidant and antimicrobial properties of this plant. The essential oil (EO) (57 constituents) included mainly α-pinene, β-pinene, nopinone, linalool, cryptone, and limonene. The plant polyphenolic contents and the antioxidant activity were determined. The antimicrobial effect of the EO and the methanolic extract (ME) was assessed against referenced and clinical bacterial strains, and also foodborne fungal isolates. The EO minimal inhibitory concentration (MIC) values varied from 0.25 to 4 mg/mL and minimal bactericidal concentrations (MBCs) were less than 8 mg/mL except for S. aureus, clinical Klebsiella, S. epidermidis, and B. subtilis. The mould strains were significantly inhibited by the EO (87.50% to 88.33%). The MIC values were 3.60-15.62 mg/mL and 0.5-4 mg/mL for ME and EO, respectively. The minimal fungicidal concentration (MFC) values ranged from 31 to 125 mg/mL and from 2 to 8 mg/mL for ME and EO, respectively.

Modified Cinnabaris-stabilized Pickering emulsions loaded with the essential oil of Acorus tatarinowii Schott: preparation, characterization and in vitro evaluation

Essential oil of Acorus tatarinowii Schott (ATEO) have significant biological activity, but their physical and chemical properties are unstable and susceptible to interference by external factors, resulting in oxidation, decomposition, and isomerization of essential oils (EOs), ultimately diminishing the quality of EOs and escalating clinical risks. In this research, based on the concept of " combination of medicine and adjuvant, " the unsuitable stabilizer Cinnabaris in Lingzhu powder prescription was modified with a SiO2 surface to become a stabilizer suitable for Pickering emulsion. The modified Cinnabaris was synthesized, with a focus on exploring the surface modification of Cinnabaris to facilitate its role as a stabilizer in Pickering emulsion. Thermal stability studies showed that modified Cinnabaris-stabilized emulsion had higher EOs retention and lower peroxide value and hydrogen peroxide content. GC-MS analysis showed that the volatile components in the emulsion were more stable than the EOs. In vitro dissolution experiments showed that in the dissolution medium of artificial gastric juice and artificial intestinal juice, compared with the ATEO, the release in Pickering emulsion was faster within 48 h, indicating that the ATEO had been encapsulated in Pickering emulsion, which could improve the in vitro dissolution rate of EOs. This study convincingly demonstrates the potential of modified Cinnabaris-stabilized Pickering emulsion to improve the thermal stability and in vitro dissolution rate of EOs.

A Comprehensive Review of Essential Oils and Their Pharmacological Activities in Neurological Disorders: Exploring Neuroprotective Potential

Numerous studies have demonstrated essential oils' diverse chemical compositions and pharmacological properties encompassing antinociceptive, anxiolytic-like, and anticonvulsant activities, among other notable effects. The utilization of essential oils, whether inhaled, orally ingested, or applied topically, has commonly been employed as adjunctive therapy for individuals experiencing anxiety, insomnia, convulsions, pain, and cognitive impairment. The utilization of synthetic medications in the treatment of various disorders and symptoms is associated with a wide array of negative consequences. Consequently, numerous research groups across the globe have been prompted to explore the efficacy of natural alternatives such as essential oils. This review provides a comprehensive overview of the existing literature on the pharmacological properties of essential oils and their derived compounds and the underlying mechanisms responsible for these observed effects. The primary emphasis is on essential oils and their constituents, specifically targeting the nervous system and exhibiting significant potential in treating neurodegenerative disorders. The current state of research in this field is characterized by its preliminary nature, highlighting the necessity for a more comprehensive overlook of the therapeutic advantages of essential oils and their components. Integrating essential oils into conventional therapies can enhance the effectiveness of comprehensive treatment regimens for neurodegenerative diseases, offering a more holistic approach to addressing the multifaceted nature of these conditions.

A review of the bioactive components and pharmacological properties of Lavandula species

Lavandula species is a flowering plant that is common in Europe and across the Mediterranean. Lavender has many health benefits for humans. In addition to its use in herbal medicine, it is widely used in the fields of cosmetics, perfumes, foods, and aromatherapy. Google Scholar, PubMed, Scopus, and Web of Science were used to search for relevant material on the phytochemical ingredients, the pharmacologic effects of the ingredients, and the mechanism of action of the Lavandula species identified. These materials were reviewed in order to have access to important updates about the Lavandula species. Lavender as referred to in English contains essential oils, anthocyanins, phytosterols, sugars, minerals, coumaric acid, glycolic acid, valeric acid, ursolic acid, herniarins, coumarins, and tannins. It has been used to treat colic and chest ailments, worrisome headaches, and biliousness, and in cleaning wounds. It has antifungal, antibacterial, neurologic, antimicrobial, anti-parasitic, anti-diabetic, and analgesic effects among others. Lavandula species has prospects for various biological applications, especially with its dermatological application. Advances in drug development would enable characterization of various bioactive constituents; thus, its development and application can have a more positive impact on humanity. Here, we highlighted updated information on the history, distribution, traditional uses, phytochemical components, pharmacology, and various biological activities of Lavandula species.

Geraniol accelerates the gastric healing, minimizes ulcers recurrence, and reduces anxiolytic-like behavior in ulcerated rodents by oral or inhaled route

BACKGROUND

Geraniol (GE) is dietary acyclic monoterpene alcohol found in essential oils from aromatic plants with therapeutic value against gastric ulcers already described.

HYPOTHESIS/PURPOSE

To assess whether oral GE accelerates gastric healing or prevents ulcer recurrence, and to evaluate the hypothesis that GE promotes antiulcer effects by the inhaled route and that promotes changes in the behavior of ulcerated rodents.

METHODS

Gastric healing effects, underlining mechanisms, and behavioral changes were measured in80% acetic acid-induced gastric ulcer model in rats receiving GE by oral (30 mg/kg) or inhaled route (1 mg/L of air/min); whereas the effects of GE to avoid ulcer recurrence was evaluated in mice submitted to 10% acetic acid plus IL-1β ulcer.

RESULTS

GE administered by both routes accelerates gastric healing, increasing mucin and GSH levels, CAT, and GST activities, and reducing MPO activity. Moreover, oral, and inhaled GE minimized ulcer recurrence reducing gastric TNF and IL-6 levels and preserving mucin levels. Interestingly, the inhalation or oral intake of GE promotes anxiolytic-like effects in ulcerated rats.

CONCLUSION

Data altogether suggest that the GE accelerates gastric healing through the strengthening of protective factors of the gastric mucosa, promoting a quality healing that reduces the recurrence of the lesion. Besides, the anxiolytic-like effect of GE may also contribute to its gastric healing action since anxiety is recognized as one of the etiologic agents of ulcers.

Origanum syriacum Phytochemistry and Pharmacological Properties: A Comprehensive Review

Herbal medicine has been gaining special interest as an alternative choice of treatment for several diseases, being generally accessible, cost-effective and safe, with fewer side-effects compared to chemically synthesized medicines. Over 25% of drugs worldwide are derived from plants, and surveys have shown that, when available, herbal medicine is the preferred choice of treatment. Origanum syriacum (Lamiaceae) is a widely used medicinal plant in the Middle East, both as a home and a folk remedy, and in the food and beverage industry. Origanum syriacum contains numerous phytochemical compounds, including flavonoids, phenols, essential oils, and many others. Because of its bioactive compounds, O. syriacum possesses antioxidant, antimicrobial, and antiparasitic capacities. In addition, it can be beneficial in the treatment of various diseases such as cancer, neurodegenerative disorders, and peptic ulcers. In this review, the chemical compositions of different types of extracts and essential oils from this herb will first be specified. Then, the pharmacological uses of these extracts and essential oils in various contexts and diseases will be discussed, putting emphasis on their efficacy and safety. Finally, the cellular and molecular mechanisms of O. syriacum phytochemicals in disease treatment will be described as a basis for further investigation into the plant's pharmacological role.

Neuroprotective Potential of Aromatic Herbs: Rosemary, Sage, and Lavender

Hundreds of millions of people around the world suffer from neurological disorders or have experienced them intermittently, which has significantly reduced their quality of life. The common treatments for neurological disorders are relatively expensive and may lead to a wide variety of side effects including sleep attacks, gastrointestinal side effects, blood pressure changes, etc. On the other hand, several herbal medications have attracted colossal popularity worldwide in the recent years due to their availability, affordable prices, and few side effects. Aromatic plants, sage (Salvia officinalis), lavender (Lavandula angustifolia), and rosemary (Salvia Rosmarinus) have already shown anxiolytics, anti-inflammatory, antioxidant, and neuroprotective effects. They have also shown potential in treating common neurological disorders, including Alzheimer's disease, Parkinson's disease, migraine, and cognitive disorders. This review summarizes the data on the neuroprotective potential of aromatic herbs, sage, lavender, and rosemary.

Study of the volatilization rules of volatile oil and the sustained-release effect of volatile oil solidified by porous starch

Volatile oil from traditional Chinese medicine has various biological activities and has pharmacological activities in the central nervous system, digestive system, cardiovascular system, respiratory system, etc. These oils are widely used in clinical practice. However, the development of their clinical applications is restricted due to the disadvantages of volatile oils, such as high stimulation, high volatility and poor stability. To improve the stability of a volatile oil in the preparation process, its volatilization and stable release must be controlled. In this paper, porous starch was used as a solid carrier material, and liquid volatile oil was solidified by physical adsorption. GC–MS was used to determine the chemical constituents of the volatile oil, solidified powder and tablets, and the volatilization rules of 34 chemical constituents were analysed statistically. The solidified volatile oil/porous starch powder was characterized by XRD, TGA and DSC, and the VOCs of the volatile oil before and after solidification were analysed by portable GC–MS. Finally, the stable release of the volatile oil could be optimized by changing the porous starch ratio in the formulation. Volatilization was shown to be closely related to the peak retention time and chemical composition, which was consistent with the theory of flavour. The physical properties and chemical composition of the volatile oil did not change after curing, indicating that the adsorption of the volatile oil by porous starch was physical adsorption. In this paper, the porous starch-solidified volatile oil had a slow-release effect, and the production process is simple, easy to operate, and has high application value.

Origanum vulgare ssp. hirtum (Lamiaceae) Essential Oil Prevents Behavioral and Oxidative Stress Changes in the Scopolamine Zebrafish Model

Origanum vulgare ssp. hirtum has been used as medicinal herbs promoting antioxidant, anti-inflammatory, antimicrobial, and neuroprotective activities. We investigated the protective effects and the mechanism of O. vulgare ssp. hirtum essential oil (OEO) on cognitive impairment and brain oxidative stress in a scopolamine (Sco)-induced zebrafish (Danio rerio) model of cognitive impairment. Our results show that exposure to Sco (100 µM) leads to anxiety, spatial memory, and response to novelty dysfunctions, whereas the administration of OEO (25, 150, and 300 µL/L, once daily for 13 days) reduced anxiety-like behavior and improved cognitive ability, which was confirmed by behavioral tests, such as the novel tank-diving test (NTT), Y-maze test, and novel object recognition test (NOR) in zebrafish. Additionally, Sco-induced brain oxidative stress and increasing of acetylcholinesterase (AChE) activity were attenuated by the administration of OEO. The gas chromatography-mass spectrometry (GC-MS) analyses were used to elucidate the OEO composition, comprising thymol (38.82%), p-cymene (20.28%), and γ-terpinene (19.58%) as the main identified components. These findings suggest the ability of OEO to revert the Sco-induced cognitive deficits by restoring the cholinergic system activity and brain antioxidant status. Thus, OEO could be used as perspective sources of bioactive compounds, displaying valuable biological activities, with potential pharmaceutical applications.

Prospects for using Origanum Syriacum (L.) as a source of antimicrobial agents

Origanum syriacum (O. syriacum) (L.) belongs to Group B of the genus Origanum from (Lamiaceae), which is rich in essential oils that exhibit antimicrobial efficacy, anti-inflammatory efficacy, antioxidant activity, and antitumor efficacy. These processing activities are because of its richness in carvacrol and Thymol. In this article, we will focus on O. syriacum, discussing the antimicrobial efficacy for its essential oil and extracts, in addition, cast light on mechanism of essential oil antimicrobial action. This study was conducted from March 2019 to February 2021. We have analyzed the results of studies on antimicrobial efficacy of a plant O. syriacum in the PubMed, Google Scholar, Elsevier over the past 15 years using keywords. O. syriacum essential oil and its extracts have an extensive antimicrobial efficacy give it a great importance in pharmaceutical and medical purposes.

Topical treatment of multiple erosive, ulcerative skin lesions in an Indian rhinoceros (Rhinoceros unicornis)

A 30-year-old, intact female Indian rhinoceros (Rhinocerus unicornis) was presented with ongoing erosive, ulcerative skin lesions over a 4-year-period. The lesions appeared to be non-pruritic and non-seasonal. A systemic antibiotic therapy had been unsuccessful. The dermatological examination showed 8 diffusely demarcated areas of erosion, focal ulceration, mild crusting, and moderate erythema ranging from 8 to 20 cm in diameter, bilaterally on the lateral edges of the torso armor plates. The patient had no other clinical abnormalities. Coccoid and rod-shaped bacteria were identified on cytology and a bacterial culture revealed Escherichia coli spp., Staphylococcus dysgalacticae, Stenotrophomonas maltophilia, Corynebacterium spp. and Micrococus spp. A topical product line containing essential fatty acids and plant extracts was administered daily, using a spot-on, spray and balm. Within 3 weeks a substantial alleviation of clinical signs was observed. Multiple impression smears of the lesions and a bacterial culture were negative by day 21. The patient achieved complete remission within 4 months of treatment and maintained remission for the 2-year observation period with continued use of the medication. Topically administered therapeutics containing essential fatty acids and plant extracts may offer a viable treatment option for recurrent cases of bacterial infectious skin lesions in Indian rhinocerotidae.

The impact of filtered water-pipe smoke on healthy versus cancer cells and their neurodegenerative role on AMPA receptor

Water pipe smoking is highly prevalent in developing countries, especially in Eastern Mediterranean regions. Research finds that more than 100 million people smoke a water pipe. Furthermore, tobacco smoking is one of the leading behavioral factors related to an increased risk of cancer, a leading cause of death globally. We aim to introduce a novel filtration system for water-pipe smoking and evaluate cytotoxic effects of common water pipe condensed smoke in comparison with our novel filtration system on normal (HEK293t) and cancer cell lines (Hep3B and MCF7) by MTS assay, alpha-fetoprotein (aFP), and apoptosis/necrosis effects. More so, the smoke substituents' neurotoxicity effect was evaluated by analyzing the depressive property on AMPA receptors (AMPARs). Our results showed that the silica filtration system was more effective than the water filtration system. The number of toxic compounds was reduced from 145 mg in distilled water extract (DWE) to 57.5 mg in silica solution extract (SSE). The SSE method also showed lower toxicity impacts on normal and cancerous cell lines (HEK293t, Hep3B, and MCF7) with CC₅₀ values 149.9, 10.14, and 8.9 µg/ml, relative to the DWE method (CC₅₀ values 77.1, 3.1, and 5.24 µg/ml, respectively). SSE extraction also reduced the α-FP (tumor marker test) to 2273.3 ng/ml which was closer in value to untreated cells (4066.7 ng/ml) in comparison with DWE which reduced it greatly to 1658.7 ng/ml, and the biophysical properties of AMPAR subunits demonstrate a reduced effect on desensitization rates of GluA2 homomer and GluA1/2 heteromer, using SSE relative to DWE. In conclusion, the condensed smoke of ordinary water pipe (DWE) has cytotoxic and neurotoxic impacts on various cell lines, while our newly developed system (SSE) was less toxic.

Antioxidant and anticancer potentials of edible flowers: where do we stand?

Edible flowers are attracting special therapeutic attention and their administration is on the rise. Edible flowers play pivotal modulatory roles on oxidative stress and related interconnected apoptotic/inflammatory pathways toward the treatment of cancer. In this review, we highlighted the phytochemical content and therapeutic applications of edible flowers, as well as their modulatory potential on the oxidative stress pathways and apoptotic/inflammatory mediators, resulting in anticancer effects. Edible flowers are promising sources of phytochemicals (e.g., phenolic compounds, carotenoids, terpenoids) with several therapeutic effects. They possess anti-inflammatory, anti-diabetic, anti-microbial, anti-depressant, anxiolytic, anti-obesity, cardioprotective, and neuroprotective effects. Edible flowers potentially modulate oxidative stress by targeting erythroid nuclear transcription factor-2/extracellular signal-regulated kinase/mitogen-activated protein kinase (Nrf2/ERK/MAPK), reactive oxygen species (ROS), nitric oxide (NO), malondialdehyde (MDA) and antioxidant response elements (AREs). As the interconnected pathways to oxidative stress, inflammatory mediators, including tumor necrosis factor (TNF)-α, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), interleukins (ILs) as well as apoptotic pathways such as Bcl-2-associated X protein (Bax), Bcl-2, caspase and cytochrome C are critical targets of edible flowers in combating cancer. In this regard, edible flowers could play promising anticancer effects by targeting oxidative stress and downstream dysregulated pathways.

Patch Clamp Technology in the Twenty-First Century

In the almost four decades since its inception, the patch clamp technique has transitioned from a specialist skill to a method commonly used among many others in a lab. Development of patch clamp instrumentation has not been steady: A boost of product releases in rapid succession by multiple manufacturers in the 1990s had slowed to a trickle by the mid-2000s. In 2016, Sutter Instrument's entry into the market of turnkey patch clamp amplifier systems, defined as an amplifier with matching data acquisition hardware and software, caused a fresh breeze in a field in danger of going stale. Sutter has meanwhile completed the product line, culminating in the flagship dPatch^® Ultra-fast, Low-noise Digital Amplifier. The dPatch System constitutes a contemporary, digital design that features many firsts, including digital signal compensation, an extremely high bandwidth and fully integrated dynamic clamp capability, paired with the increasingly popular SutterPatch^® Software.This chapter compares feature sets of the new Sutter instrumentation with the established platforms by the other two providers of turnkey systems, Axon Instruments by Molecular Devices and HEKA Elektronik by Harvard Bioscience. A variety of products from other manufacturers, who rely on combination with components from other sources rather than offering turnkey systems, are listed, but for their conceptual diversity not compared at a great level of detail. The chapter further covers architectural considerations for patch clamp systems, headstage design, data acquisition strategies and efficient structuring of the recorded data, controlling and monitoring periphery, advanced technologies, such as software lock-in amplifier capability and dynamic clamp features, and application modules for efficient analysis of action potentials and postsynaptic events.

Glechoma curviflora Volatile Oil from Palestine: Chemical Composition and Neuroprotective, Antimicrobial, and Cyclooxygenase Inhibitory Activities

The rise of the emergence of microbial resistance of antibiotics, the dangerous side effects of nonsteroidal anti-inflammatory drugs, and noncompetent medications of Alzheimer's, Parkinson's, and other neurodegenerative diseases prompt scientists to search for phytochemicals that could be utilized in the remedy of lethal diseases. Glechoma curviflora (Boiss.) Kuntze (Nepeta curviflora) is a medicinal herb growing in the eastern parts of the Mediterranean Sea Basin and is widely consumed as a tea. The leaves of this plant have been traditionally used for the treatment of various infectious diseases. The current research was designed to identify the chemical composition of Glechoma curviflora (Boiss.) essential oil (EO) and to assess its antibacterial, antifungal, and cyclooxygenase inhibitory activities and the biophysical gating effect on AMPA receptors. Twenty phytochemicals were identified from G. curviflora leaves and flowers EO amounting to almost 100% of the total constituents using GC-MS technique, of which 1,6-dimethylspiro[4.5]decane (27.51%) 1, caryophyllene oxide (20.08%) 2, and β-caryophyllene (18.28%) 3 were the main constituents. The biophysical properties' effect from the plant extract on various AMPA-type receptors expressed in Human Embryonic Kidney (HEK293) cells was assessed by exploiting the whole-cell patch-clamp technique. Microdilution assay was adopted for assessing the antimicrobial property against eight virulent microbial strains whilst the cyclooxygenase inhibition effect was accomplished utilizing COX inhibitory screening colorimetric assay G. curviflora EO displayed potent activity against P. aeruginosa (MIC = 1.25 μg/mL), S. sonnei (MIC = 3.12 μg/mL), and E. coli (MIC = 1.25 μg/mL), compared with ciprofloxacin (positive control) and potent antibacterial activity against S. aureus, MRSA, S. sonnei, E. coli, and P. aeruginosa compared to Ampicillin (2nd positive control). It also showed anti-Candida (MIC = 6.25 μg/mL) and antimold (MIC = 3.125 μg/mL) activities compared with fluconazole (antifungal positive control). Likewise, our results showed an inhibition and biophysical impact of G. curviflora on all AMPARs subunits.

Lavandula dentata from Italy: Analysis of Trichomes and Volatiles

This study presented a micromorphological and phytochemical survey on Lavandula dentata L. cultivated at the Ghirardi Botanic Garden (Toscolano Maderno, BS, Italy). The morphological investigation revealed the presence of peltate, short- and medium-stalked capitate trichomes. The histochemical survey showed terpene production by peltates and medium-stalked capitates, hydrophilic secretions by short-stalked capitates. The phytochemical survey was developed on leaf and flower volatile organic compounds (VOCs) and on the essential oil (EO) from the flowering aerial parts. The VOC profiles represented an element of novelty and were dominated by oxygenated monoterpenes, among which 1,8-cineole and β-pinene were the most abundant (77.40 %, 7.11 % leaves; 81.08 %, 10.46 % flowers). The EO of L. dentata was dominated by oxygenated monoterpenes with a high percentage of 1,8-cineole (69.08 %), followed by β-pinene, trans-pinocarveol and myrtenal. Evaluations about the ecological role, the potential biological activity and the sensory attributes were proposed, based on literature contributions.

Synthesis and Biological Evaluation of Benzodioxol Derivatives as Cyclooxygenase Inhibitors

Background:

Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most widely used therapeutics; they are competitive inhibitors of cyclooxygenase (COX), the enzyme which mediates the conversion of arachidonic acid to inflammatory prostaglandins.

Objective:

In this study, new benzodioxol derivatives with different core cycles and functional groups (i.e., aryl acetate, aryl acetic acid and diazepine) were designed, synthesized, identified and evaluated for their analgesic and anti-inflammatory activity, as a preliminary screening study to identify the most potent and more selective groups.

Methods:

The synthesized compounds were identified using FTIR, HRMS, 1H-NMR and 13C-NMR, and evaluated for their inhibitory activity against ovine COX-1 and COX-2 using an in vitro cyclooxygenase (COX) inhibition assay kit.

Results:

Six compounds were synthesized as a preliminary screening study to identify which was the most potent and more selective group towards COX-2 versus COX-1, compared to ketoprofen as non-selective NSAIDs. The compounds have three different groups: aryl acetate, aryl acetic acid and diazepine. The results showed that the most potent compound against the COX- 1 enzyme was 4b (which has diazepine and 2-chlorophenyl) with IC50 = 0.363 μM, and the selectivity ratio of 4b was found to be better than ketoprofen. In contrast, compound 4a (which has diazepine and 3-chlorophenyl) was the most selective with a COX-1/COX-2 ratio value of 0.85 in comparison with a ketoprofen ratio value of 0.20.

Conclusion:

In general, the synthesized library has moderate activity against both enzymes (i.e., COX-1 and COX-2). Moreover, all six compounds have better COX-2 inhibition selectivity compared to the commercial drug ketoprofen.

Ortho versus Meta Chlorophenyl-2,3-Benzodiazepine Analogues: Synthesis, Molecular Modeling, and Biological Activity as AMPAR Antagonists

2,3-Benzodiazepine compounds are an important family of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) antagonists that act in a noncompetitive manner. Due to the critical role of AMPARs in the synapse and various neurological diseases, significant scientific interest in elucidating the molecular basis of the function of the receptors has spiked. The analogues were synthesized to assess the functional consequence of removing the amine group of the phenyl ring, the potency and efficacy of inhibition by substituting a halogen group at the meta vs ortho position of the phenyl ring, and layout the prediction of potential drug candidates for AMPAR hyperactivation. Using the whole-cell patch-clamp technique, we assessed the effect of the derivative on the amplitude of various AMPA-type glutamate receptors and calculated the desensitization and deactivation rates before and after treatment of HEK293 cells. We noticed that the amino group is not necessary for inhibition as long as an electron-withdrawing group is placed on the meta position of the phenyl ring of BDZ. Furthermore, compound 4a significantly inhibited and affected the desensitization rate of the tested AMPARs but showed no effect on the deactivation rate. The current study paves the way to a better understanding of AMPARs and provides possible drug candidates of 2,3-BDZ different from the conventional derivatives.

Effect of Geraniol and Citronellol Essential Oils on the Biophysical Gating Properties of AMPA Receptors

Essential oils have been advertised endlessly to be very beneficial for the health of humans, and an extensive amount of research examines the validity of such claims. In contribution, the current study evaluates the neuroprotective properties of Citronellol and Geraniol essential oils (EOs). In relationship to the biophysical gating properties of different the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) subunits, the EOs were administered to HEK293 (Human embryonic kidney 293) cells and examined for any inhibition and effect on desensitization or deactivation rates, using whole-cell patch-clamp electrophysiology. Our results demonstrated the highest levels of inhibition from Citronellol oil by four-fold on all AMPARs subunits. Likewise, Geraniol oil had a similar inhibiting impact on the receptors, and both oils decreased the desensitization and deactivation rates of the inhibited receptors. Thus, the examined EOs of this study portray neuroprotective qualities by targeting AMPARs activation and reducing desensitization and deactivation rates. Finally, the results of the current study entail a better understanding of AMPARs, provides a natural template for future drug synthesis to treat neurological diseases associated with excessive AMPAR activation, and offers a possible mechanism by which these essential oils deploy their ‘calming’ effect.

Inhibition and assessment of the biophysical gating properties of GluA2 and GluA2/A3 AMPA receptors using curcumin derivatives

The development of efficacious and safe drugs for the treatment of neurological diseases related to glutamate toxicity has been a focus in neuropharmacological research. Specifically, discovering antagonists to modulate the activity and kinetics of AMPA receptors, which are the fastest ligand-gated ion channels involved in excitatory neurotransmission in response to glutamate. Thus, the current study investigated novel curcumin derivatives on the biophysical properties of AMPA receptors, specifically on the homomeric GluA2 and the heteromeric GluA2/A3 subunits and assessed for inhibitory actions. The biophysical parameter (i.e., desensitization, deactivation, and peak currents) were measured by using whole-cell patch clamp electrophysiology with and without the administration of the derivatives onto HEK293 cells. CR-NN, CR-NNPh, CR-MeNH, and CR-NO of the tested derivatives showed inhibition on all AMPA receptors up to 6 folds. Moreover, the inhibitory derivatives also increased desensitization and deactivation, which further intensifies the compounds' neuroprotective effects. However, CR-PhCl, CR-PhF, and CR-PhBr did not show any significant changes on the peak current, deactivation or desensitization rates. By comparison to other discovered and widely used antagonist, the prepared curcumin derivatives are not selective to a specific AMPA subunit, instead implement its effect in the same way between all types of AMPA receptors. Additionally, the obtained results provide derivatives that not only noncompetitively inhibit AMPARs but also decrease its biophysical kinetics, specifically desensitization and deactivation rates. Hence, to potentially serve as a new AMPAR inhibitor with therapeutic potential, the current study provides compounds that are non-selective and non-competitive antagonist, which also effect the desensitization and deactivation rates of the receptor.