Allium hookeri Extracts Improve Scopolamine-Induced Cognitive Impairment via Activation of the Cholinergic System and Anti-Neuroinflammation in Mice

Metabolite Profiling of Allium hookeri Leaves Using UHPLC-qTOF-MS/MS and the Senomorphic Activity of Phenolamides

The plant Allium hookeri, a member of the Allium genus, has a rich history of culinary and medicinal use. Recent studies have unveiled its potent antioxidant and anti-inflammatory properties. While research on A. hookeri has demonstrated its neuroprotective and anti-neuroinflammatory effects, the specific bioactive compounds responsible for these effects remain unidentified in prior research. This study utilized an untargeted metabolomic approach, employing HRESI-qTOF MS/MS-based molecular networking, to comprehensively profile the chemical composition of metabolites in A. hookeri and identify new compounds within the plant. As a result, ten compounds, comprising one novel flavonoid (2) and nine known compounds (1 and 3-10), were isolated and identified through NMR analysis. The inhibitory effects of all isolated compounds on the senescent cell-associated secretory phenotype (SASP), which is pivotal in neuroprotective actions, were evaluated. Biological activity testing revealed N-trans-feruloyltyramine (7) to be the most potent compound, effectively inhibiting SASP markers and contributing to the senomorphic activities of A. hookeri. These findings underscore the potential of phenolamides from A. hookeri as a promising source of bioactive compounds for mitigating senescence-associated diseases.

Combining donepezil and memantine via mannosylated PLGA nanoparticles for intranasal delivery: Characterization and preclinical studies

The current work is focused on developing mannose-coated PLGA nanoparticles for delivering Donepezil and Memantine in one dosage form. The formulated nanoparticles were prepared using a simple emulsification technique. The final coated NPs exhibited 179.4 nm size and - 33.1 mV zeta potential and spherical shape. The concentration of IN-administrated MEM and DPZ mannose coated NPs in brain was ~573 and 207 ng/mL respectively. This amount accounts for 3 times more in comparison to uncoated NPs administered via intranasal and peroral routes. The plasma concentration of coated NPs administered via the intranasal route was various times less in comparison to other groups. In the field of pharmacodynamics, the administration of coated NPs via the IN route has shown superior efficacy in comparison to other groups in various investigations involving neurobehavioral assessments, gene expression analyses and biochemical estimations. The findings indicate that the IN route may be a potential avenue for delivering therapeutic agents using nanoparticles to treat neurological illnesses. This approach shows promise as a viable alternative to traditional dose forms and administration methods.

Supplementary Effects of Allium hookeri Extract on Glucose Tolerance in Prediabetic Subjects and C57BL/KsJ-db/db Mice

Allium hookeri (AH) has been used as a nutritional and medicinal food in Asia for many years. Our previous studies have described its anti-diabetic, anti-obesity, and anti-inflammatory activities in animal models and prediabetes. This study investigated whether AH could improve glycemia by modulating insulin secretion in prediabetic subjects through an in-depth study. Eighty prediabetic subjects (100 ≤ fasting plasma glucose < 140 mg/dL) were randomly assigned to a placebo (n = 40) group or an ethanol AH extract (500 mg/day, n = 40) group for 12 weeks. Dietary intake and physical activity, blood glucose (an oral glucose tolerance test for 120 min), insulin (insulin response to oral glucose for 120 min), area under the curve (AUC) of glucose or insulin after oral glucose intake, insulin sensitivity markers, C-peptide, adiponectin, glycated hemoglobin A1c (HbA1c) levels, hematological tests (WBC, RBC, hemoglobin, hematocrit, and platelet count), blood biochemical parameters (ALP, AST, total bilirubin, total protein, albumin, gamma-GT, BUN, creatinine, LD, CK, and hs-CRP), and urine parameters (specific gravity and pH) were examined at both baseline and 12 weeks after supplementation with placebo or AH capsules. Fifty-eight participants (placebo group: 20 men and 10 women; AH group: 13 men and 15 women) completed the study. AH supplementation moderately reduced postprandial blood glucose at 60 min (-6.14 mg/dL, p = 0.061), postprandial insulin levels at 90 min (-16.69 µU/mL, p = 0.017), the glucose AUC at 90 min (-412.52 mg*min/dL, p = 0.021), as well as the insulin AUC at 90 min (-978.77 µU*min/mL, p = 0.021) and 120 min (-1426.41 µU*min/mL, p = 0.015) when compared with the placebo group. However, there were no effects of AH on dietary intake and physical activity; HOMA index; HbAlc; C-peptide; or adiponectin, hematological-, blood biochemical-, and urinary markers. To confirm the effects of AH extract on blood glucose insulin sensitivity, C57BL/6J or C57BL/KsJ-db/db mice were used (n = 8/group). Body weight, fasting plasma glucose level, lipid profiles, liver and renal function, pancreatic histology, and insulin immunoreactivity were assessed. In the diabetic db/db mice, hyperglycemia, which was accompanied by an increase in insulin secretion in diabetic mice, was significantly reduced by AH treatment, resulting in the alleviation of β-cell overcompensation and insulin resistance. We confirmed that AH supplementation can effectively control blood glucose and insulin levels by improving insulin sensitivity and may be a potential agent for glycemic control in subjects with prediabetes and type 2 diabetes mellitus.

Neuroprotective Effect of Saroglitazar on Scopolamine-Induced Alzheimer's in Rats: Insights into the Underlying Mechanisms

Alzheimer's disease (AD) is one of the most prevalent and progressive neurodegenerative disorders, hallmarked by increased amyloid-β deposition and enhanced oxidative load in the brain, ensuing cognitive decline. The present study is aimed at elucidating the neuroprotective effect of saroglitazar, a dual peroxisome-proliferator-activated receptor (PPARα/γ) agonist used in the treatment of diabetic dyslipidemia, against memory impairment induced by intraperitoneal scopolamine injection. 30 male Wistar rats were randomly divided into the following five groups: (A) Veh + Veh, (B) SGZ + Veh, (C) Veh + SCOP, (D) DPZ + SCOP, and (E) SGZ + SCOP. Rats of the respective groups were pretreated with saroglitazar (10 mg/kg, p.o.) and donepezil (3 mg/kg, p.o.) once daily for 16 days. During the final 9 days of the study, a daily injection of scopolamine (3 mg/kg, i.p.) was administered to the respective groups. Adjacent to the scopolamine injection, behavioral tests such as the open field, Y maze, novel object recognition test, and Morris water maze were conducted to assess learning and memory. Additionally, biochemical parameters such as acetylcholinesterase (AChE), butyrylcholinesterase (BuChE), nitric oxide (NO), malondialdehyde (MDA), reduced glutathione (GSH), superoxide dismutase (SOD), brain-derived neurotrophic factor (BDNF), β-amyloid levels, and NF-κB were measured in the hippocampus. The rats that received scopolamine injections showed significantly impaired short-term spatial and learning memory. This was associated with an increase in β-amyloid, iNOS, nitric oxide (NO), malondialdehyde, NF-κB, and TNF-α levels in the hippocampus of AD rats. On the other hand, saroglitazar has provided promising data on its protective role in cognition by protecting the BDNF, SOD, and GSH decline. As a result, saroglitazar was found to be a promising therapy in AD by upregulating the antioxidant status and cholinergic activity and preventing memory loss. Collectively, findings in the present study revealed that saroglitazar protected AD by suppressing scopolamine-mediated learning and memory deficits, oxidative stress, and cholinergic damage. Studying these mechanisms may conclude the protective role of saroglitazar against AD. However, further studies in transgenic animals will provide numerous insights into treatment mechanisms and contribute to developing a therapeutic intervention for AD.

Simultaneous Intranasal Codelivery of Donepezil and Memantine in a Nanocolloidal Carrier: Optimization, Pharmacokinetics, and Pharmacodynamics Studies

This work focuses on developing nanoemulsions using a low-energy emulsification method for the codelivery of donepezil and memantine in one dosage form intended to be administered via the intranasal route for enhanced brain delivery. The nanoemulsion formulation was prepared using a low emulsification technique and characterized using various microscopy and nasal ciliotoxicity studies. The safe nanoemulsion was intended for preclinical pharmacokinetics with brain distribution and pharmacodynamics in a scopolamine-induced murine model. The formulated nanoemulsion was 16 nm in size, with a zeta potential of -7.22 mV, and exhibited a spherical shape. The brain concentration of IN-administered NE for DPZ and MEM was ∼678 and 249 ng/mL after 15 min. This concentration is more than 2 times higher in amount when compared with NE administered via PO, free drug solution administered via IN and PO route both. However, the plasma concentration of IN-administered NE for DPZ and MEM was ∼3 and 28 ng/mL after 15 min. In pharmacodynamic studies, the efficacy of NE administered via the IN route was higher when compared with other groups in neurobehavioral, biochemical estimation, and gene expression studies. The results suggest that the IN route can be explored in the future for the delivery of actives via nanocolloidal carriers in the brain for neurological disorders and can serve as promising alternatives for conventional dosage forms and routes.

Barbigerone prevents scopolamine-induced memory impairment in rats by inhibiting oxidative stress and acetylcholinesterase levels

The current study was designed for the evaluation of barbigerone on memory loss. In this experimental study, 24 Wistar rats (n = 6) were used. Control rats and scopolamine (SCOP)-treated control group rats were orally administered with 3 ml of 0.5% sodium carboxymethyl cellulose (vehicle), whereas barbigerone was (10 and 20 mg kg^-1) administered orally to the rats from the test group. During the 14-day treatment, control group rats were given 3 ml kg^-1 day^-1 saline, and all other groups were administered SCOP (1 mg kg^-1 day^-1, i.p.) 1 h after barbigerone p.o. treatment. The spontaneous alternation activities, learning capacities of a rat's memory were tested with Morris water maze and Y-maze. Reduced glutathione, malondialdehyde, acetylcholine esterase (AChE) and catalase (CAT) levels were measured in rat brain tissue as oxidative stress/antioxidant markers. Moreover, the levels of tumour necrosis factor, interleukin-6 (IL-6) and IL-1β were also estimated. Treatment with barbigerone in SCOP-administered rats dramatically reduced SCOP-induced neurobehavioural deficits, oxidative stress and neuroinflammatory markers, improved endogenous antioxidants, and restored AChE activity. By improving cholinergic function and reducing oxidative damage, barbigerone could mitigate the effects of SCOP-induced changes in the brain.

Antioxidant and Immune Stimulating Effects of Allium hookeri Extracts in the RAW 264.7 Cells and Immune-Depressed C57BL/6 Mice

We investigated the antioxidant and immune-enhancing effects of the extracts from Allium hookeri leaves and roots (AHL and AHR) in in vitro and in vivo models. Their antioxidant effects were determined by total phenolic content (TPC), DPPH and ABTS radical scavenging activities, and superoxide dismutase and catalase activities. The immunomodulatory effects were evaluated by nitric oxide (NO) production and cytokine concentrations produced from RAW 264.7, and by serum IgA and IgG levels, cytokine levels, and NK cell activities in the immunosuppressed C57BL/6 mice. AHL and AHR extracts improved antioxidant activities and productions of NO and cytokines without cytotoxicity in the RAW 264.7 cells. AHL and AHR groups showed significantly higher serum IgA and IgG levels, Th1 cytokine concentrations, splenocyte proliferations, and NK cell activities than the NC group which was not treated with AHL or AHR extract. AHR extract showed higher values than AHL extract in the factors evaluated in this study. The results show that they have high antioxidant and immunomodulatory effects and can be used as novel potential therapeutic candidates to treat related diseases and to improve public health.

Flavonoid Derivatives as Potential Cholinesterase Inhibitors in Scopolamine-Induced Amnesic Mice: An In Vitro, In Vivo and Integrated Computational Approach

Flavonoids are one of the most exciting types of phenolic compounds with a wide range of bioactive benefits. A series of flavone derivatives (F1–F5) were previously synthesized from substituted O-hydroxy acetophenone and substituted chloro-benzaldehydes. The titled compounds F1–F5 in the present study were evaluated for their anticholinesterase potential (against AChE and BuChE). The obtained results were then validated through a molecular docking approach. Compound F5 was found to be the most potent inhibitor of AChE (IC₅₀ = 98.42 ± 0.97 µg/mL) followed by compound F4, whereas compound F2 was found to be the most promising inhibitor of BuChE (IC₅₀ = 105.20 ± 1.43 µg/mL) among the tested compounds. The molecular docking analysis revealed a similar trend in the binding affinity of compounds with the targeted enzymes and found them to be capable of forming highly stable complexes with both receptors. The selected compounds were further subjected to in vivo assessment of cognitive function in a scopolamine-induced amnesic animal model, in which almost all compounds F1–F5 significantly attenuated the amnesic effects as evaluated through Y-Maze Paradigm and novel object discrimination (NOD) tasks, findings that were further supported by ex vivo experimental results. Among (F1–F5), F5 showed significant anti-amnesic effects in scopolamine-induced amnesic models and ameliorated the memory loss in behavioral model studies as compared to counterparts. In ex vivo study, noteworthy protection from oxidative stress in the brains of scopolamine-induced amnesic mice was also recorded for F5. These findings also confirmed that there were no significant differences among the in vivo and ex vivo results after administration of F1–F5 (7.5 or 15 mg/kg) or donepezil (2 mg/kg). These synthesized flavonoids could serve as potential candidates for new neuroprotective and nootropic drugs. However, further studies are needed to validate their observed potential in other animal models as well.

Underlying Mechanism and Active Ingredients of Tianma Gouteng Acting on Cerebral Infarction as Determined via Network Pharmacology Analysis Combined With Experimental Validation

Cerebral infarction (CI), a common cerebrovascular disease worldwide, is caused by unknown factors common to many diseases, including hypokalemia, respiratory diseases, and lower extremity venous thrombosis. Tianma Gouteng (TMGT), a traditional Chinese Medicine (TCM) prescription, has been used for the clinical treatment of CI. In this study, high-performance liquid chromatography (HPLC) fingerprint analysis was used to detect and identify major chemical constituents of TMGT. TCMSP and BATMAN-TCM databases were used to screen for active TMGT constituent compounds, while the GeneCards database was used to screen for protein targets associated with CI. Next, GO and KEGG enrichment analysis of these core nodes were performed to determine the identities of key associated biological processes and signal pathways. Meanwhile, a total of six possible gene targets of TMGT, including NFKBIA, PPARG, IL6, IL1B, CXCL8, and HIF1A, were selected for further study using two cellular models of CI. For one model, PC12 cells were treated under oxygen and glucose deprivation (OGD) conditions to generate an OGD cellular model of CI, while for the other model, BV2 cells were stimulated with lipopolysaccharide (LPS) to generate a cellular model of CI-associated inflammation. Ultimately TMGT treatment increased PPARγ expression and downregulated the expression of p-P65, p-IκBα, and HIF-1α in both OGD-induced and LPS-induced cell models of CI. In addition, molecular docking analysis showed that one TMGT chemical constituent, quercetin, may be a bioactive TMGT compound with activity that may be associated with the alleviation of neuronal damage and neuroinflammation triggered by CI. Moreover, additional data obtained in this work revealed that TMGT could inhibit neuroinflammation and protect brain cells from OGD-induced and LPS-induced damage by altering HIF-1α/PPARγ/NF-κB pathway functions. Thus, targeting this pathway through TMGT administration to CI patients may be a strategy for alleviating nerve injury and neuroinflammation triggered by CI.