Anticholinesterase Activity of Budmunchiamine Alkaloids Revealed by Comparative Chemical Profiling of Two Albizia spp., Molecular Docking and Dynamic Studies

UHPLC-QTOF-MS/MS profiling, molecular networking, and molecular docking analysis of Gliricidia sepium (Jacq.) Kunth. ex. Walp. stem ethanolic extract and its gastroprotective effect on gastritis in rats

Metabolic profiling of the crude ethanolic extract of Gliricidia sepium (Jacq.) Kunth. ex. Walp. stem ethanolic extract (GSS) was conducted using ultra-high performance quadrupole time of flight mass spectrometry/mass spectrometry (UHPLC-QTOF-MS/MS) in negative mode, resulting in the identification of 23 compounds belonging to various classes such as flavonoids, fatty acids, triterpenoid saponins, and phenolic acids. Notably, eight flavonoids including kaempferol-3-O-robinoside-7-O-rhamnoside, isoquercitrin, kaempferol-3-O-rutinoside, apigenin-7-glucoside, kaempeferol-7-O-rhamnoside, luteolin, apigenin, and liquiritigenin, along with two phenolic acids (4-hydroxycinnamic acid and 2-hydroxyhydrocinnamic acid) and four triterpenoid saponins (soyasaponin I, soyasaponin II, soyasaponin III, and kaikasaponin III) were dereplicated. Additionally, nine fatty acid derivatives were identified, including azelaic acid and 2-isopropyl malic acid. Molecular networking analysis revealed the formation of clusters among compounds while others do not form clusters. Further analysis indicated that the GSS ethanolic extract exhibited a total phenolic content of 38.78 ± 1.609 µg of gallic acid equivalent/mg and a total flavonoid content of 5.62 ± 0.50 µg of rutin equivalent/mg. Biological evaluations showed that GSS ethanolic extract mitigated gastric tissue injury induced by pyloric ligation, with a notable reduction in oxidative stress marker reactive oxygen species levels and inflammatory cytokines interleukin-6 and tumor necrosis factor-alpha levels. Additionally, it enhanced superoxide dismutase and inhibitor of nuclear factor kappa B alpha levels, while lowering the expression of inducible nitric oxide synthase. Histopathological examination revealed significant improvements in gastric tissue morphology in GSS-treated groups compared to the control group. Molecular docking studies indicated potential interactions between GSS ethanolic extract compounds and various target proteins involved in oxidative stress, inflammation, and gastric protection in gastritis. This study aims to investigate the potential gastroprotective activity of GSS ethanolic extract against gastritis induced via pyloric ligation.

Steroids from the mushroom Ganoderma shandongense and their AChE inhibitory activities

Investigation of the solid culture of Ganoderma shandongense led to the isolation of 15 compounds, including one new steroid (compound 1) and fourteen known ones (compounds 2-15). Their structures were determined via extensive the nuclear magnetic resonance (NMR) spectroscopic analyses and quantum chemical calculations. Compounds 3, 9, and 14 exhibited inhibitory activities against acetylcholinesterase (AChE), with half maximal inhibitory concentration (IC50) values of 29.4, 29.4 and 33.2 µM, respectively. Furthermore, molecular docking studies were undertaken to elucidate the interaction mechanisms between the compounds and the amino acid residues of AChE.

Cognitive-enhancing effect of Cordia dichotoma fruit on scopolamine-induced cognitive impairment in rats: metabolite profiling, in vivo, and in silico investigations

Many plants are reported to enhance cognition in amnesic-animal models. The metabolite profile of Cordia dichotoma fruit methanolic extract (CDFME) was characterized by LC-QTOF-MS/MS, and its total phenolics content (TPC) and total flavonoids content (TFC) were determined. In parallel, its cognitive-enhancing effect on scopolamine (SCOP)-induced AD in rats was evaluated. The TPC and TFC were 44.75 ± 1.84 mg gallic acid equiv. g-1 sample and 5.66 ± 0.67 mg rutin equiv. g-1 sample, respectively. In total, 81 metabolites were identified, including phenolic acids, lignans, coumarins, amino acids, fatty acids, and their derivatives, fatty acid amides, polar lipids, terpenoids, and others. The most abundant metabolites identified were quinic acid, caffeoyl-4'-hydroxyphenyllactate, rosmarinic acid, and oleamide. CDFME (200 mg kg-1) was found to significantly enhance recognition memory in the novel object recognition test. Furthermore, it nearly corrected acetylcholinesterase (AChE), acetylcholine, noradrenaline, and dopamine hippocampal levels, which changed due to SCOP. Further in silico validation of the in vivo results was conducted, focusing on the most abundant metabolites. Molecular docking showed that rosmarinic acid, caffeoyl-4'-hydroxyphenyllactate, sebestenoid C, and sagerinic acid exhibited the greatest affinity for receptor binding against AChE. However, molecular dynamics and mechanics calculations clarified that the complex of caffeoyl-4'-hydroxyphenyllactate with AChE was the most stable one. This study represents the first comprehensive metabolite profiling of CDFME to assess its cognition-enhancing effect both in vivo and in silico. These results demonstrate that CDFME protects against SCOP-induced cognitive impairment. Thus, additional preclinical and clinical studies on CDFME may provide an attractive approach in pharmacotherapy and AD prophylaxis.

Metabolites profiling, in-vitro and molecular docking studies of five legume seeds for Alzheimer's disease

Even though legumes are valuable medicinal plants with edible seeds that are extensively consumed worldwide, there is little information available on the metabolic variations between different dietary beans and their influence as potential anti-cholinesterase agents. High-resolution liquid chromatography coupled with mass spectrometry in positive and negative ionization modes combined with multivariate analysis were used to explore differences in the metabolic profiles of five commonly edible seeds, fava bean, black-eyed pea, kidney bean, red lentil, and chickpea. A total of 139 metabolites from various classes were identified including saponins, alkaloids, phenolic acids, iridoids, and terpenes. Chickpea showed the highest antioxidant and anti-cholinesterase effects, followed by kidney beans. Supervised and unsupervised chemometric analysis determined that species could be distinguished by their different discriminatory metabolites. The major metabolic pathways in legumes were also studied. Glycerophospholipid metabolism was the most significantly enriched KEGG pathway. Pearson's correlation analysis pinpointed 18 metabolites that were positively correlated with the anti-cholinesterase activity. Molecular docking of the biomarkers to the active sites of acetyl- and butyryl-cholinesterase enzymes revealed promising binding scores, validating the correlation results. The present study will add to the metabolomic analysis of legumes and their nutritional value and advocate their inclusion in anti-Alzheimer's formulations.

Nuciferol C, a new sesquineolignan dimer from Cocos nucifera L.: bioactivity and theoretical investigation

Nuciferol C (NC), an undescribed dimer of nuciferol B (NB), was isolated from the endocarp of Cocos nucifera L. The planar structure of NC was determined using 1D- and 2D-NMR spectroscopy as well as high resolution MS spectrometry. The absolute configuration was concluded based on analysis of NOESY spectra. NC showed cytotoxic activity against colon cancer cells (CaCo-2) with an IC50 value of 76 μM, and significantly decreased the expression of human epidermal growth factor receptor (EGFR) and tumor necrosis factor alpha (TNF-α) in CaCo-2 as compared with untreated cells by 39% and 33%, respectively (p < 0.05). In addition, NC exhibited anti-herpes simplex virus (HSV-I) activity with an IC50 value of 23 μM. In silico study of NC was implemented at three levels: density functional theory (DFT) was used to study its electronic properties, molecular mechanics was used to estimate the docking results, and finally, molecular dynamic simulation was used to study the behavior and stability of NC inside the active site of the target protein of HSV-1.

Metabolic profiling of Vitex Pubescens Vahl bark via UPLC-ESI-QTOF/MS/MS analysis and evaluation of its antioxidant and acetylcholinesterase inhibitory activities

BACKGROUND

Alzheimer's disease is a neurodegenerative age-related disease that primarily affects the elderly population leading to progressive memory impairments and neural deficits. It is counted as a major cause of geriatric dependency and disability. The pathogenesis of Alzheimer's disease incidence is complex and involves various hypotheses, including the cholinergic hypothesis, deposition of β-amyloid plaques, neuroinflammation, oxidative stress, and apoptosis. Conventional treatments such as donepezil aim to delay the symptoms but do not affect the progression of the disease and may cause serious side effects like hepatoxicity. The use of natural candidates for Alzheimer's disease treatment has drawn the attention of many researchers as it offers a multitargeted approach.

METHODS

This current study investigates the metabolic profiles of total defatted methanolic extract of Vitex pubescens bark and its polar fractions, viz. ethyl acetate and n-butanol, using ultra-performance liquid chromatography-electrospray ionization-quadrupole time-of-flight tandem mass spectrometry(UPLC-ESI-QTOF/MS/MS) technique as well as evaluate the antioxidant using free radical scavenging assays, viz. DPPH and ABTS assays and in-vitro acetylcholinesterase inhibitory activities using Ellman's microplate assay.

RESULTS

Metabolic profiling revealed a total of 71, 43, and 55 metabolites tentatively identified in the defatted methanolic extract, ethyl acetate, and n-butanol fractions, respectively. Phenolic acids were the most abundant class, viz. benzoic acids, and acyl quinic acid derivatives followed by flavonoids exemplified mainly by luteolin-C-glycosides and apigenin-C-glycosides. Quantification of the total phenolic and flavonoid contents in the total defatted methanolic extract confirmed its enrichment with phenolics and flavonoids equivalent to 138.61 ± 9.39 µg gallic acid/mg extract and 119.63 ± 4.62 µg rutin/mg extract, respectively. Moreover, the total defatted methanolic extract exhibited promising antioxidant activity confirmed through DPPH and ABTS assays with a 50% inhibitory concentration (IC50) value equivalent to 52.79 ± 2.16 µg/mL and 10.02 ± µg/mL, respectively. The inhibitory activity of acetylcholine esterase (AchE) was assessed using in-vitro Ellman's colorimetric assay, the total defatted methanolic extract, ethyl acetate, and n-butanol fractions exhibited IC50 values of 52.9, 15.1 and 108.8 µg/mL that they proved the significant inhibition of AchE activity.

CONCLUSION

The results obtained herein unraveled the potential use of the total methanolic extract of Vitex pubescens bark and its polar fractions as natural candidates for controlling Alzheimer's disease progression.

Sub-chronic oral toxicity study of the alkaloid rich fraction from Luffa cylindrica fruit in Sprague-Dawley rats

The loofah/sponge gourd Luffa cylindrica (L.), a member of the Cucurbitaceae family, is one of the neglected medicinal plants. Traditionally, Luffa cylindrica is prescribed for inducing labor. It has a long history of use in China for the treatment of fever, diabetes, dyspnea, and dysentery. This study investigated the toxicity profile of the alkaloid-rich fraction of Luffa cylindrica (ARF-LC) for the first time in Sprague Dawley rats. A total of 80 rats (40 male and 40 female rats) aged 13 weeks old and weighing 200-220 g were selected for this study. In SD rats, sub-chronic oral toxicity was investigated at doses of 100, 200, and 400 mg/kg/d for a total of 90 days, followed by a 30-day recovery period. The results showed no variation in body weight among the three dose groups compared to the control group. Treatment-related adverse events, such as alterations in hematology and serum biochemistry parameters and the histology of the liver were sporadic in the high-dose rats but within the reference range. However, these changes disappeared after the doses were withdrawn during the recovery period. In conclusion, the "no observed adverse effect level" (NOAEL) of oral administration of ARF-LC in SD rats was considered 400 mg/kg/d and can be studied for its potential in further in vivo chronic investigations.

Computational studies and structural insights for discovery of potential natural aromatase modulators for hormone-dependent breast cancer

Introduction

The aromatase enzyme plays an important role in the progress of hormone-dependent breast cancer, especially in estrogen receptor-positive (ER+) breast cancers. In case of postmenopausal women, the aromatization of androstenedione to estrone in adipose tissue is the most important source of estrogen. Generally 60%-75% of pre- and post-menopausal women suffer from estrogen-dependent breast cancer, and thus suppressing estrogen has been recognized to be a successful therapy. Hence, to limit the stimulation of estrogen, aromatase inhibitors (AIs) are used in the second-line treatment of breast cancer.

Methods

The present computational study employed an in silico approach in the identification of natural actives targeting the aromatase enzyme from a structurally diverse set of natural products. Molecular docking, QSAR studies and pharmacophore modeling were carried out using the VLife Molecular Design Suite (version 4.6). The stability of the compounds was confirmed by molecular dynamics.

Results

From molecular docking and analysis of interactions with the amino acid residues of the binding cavity, it was found that the amino acid residues interacting with the non-steroidal inhibitors exhibited π-stacking interactions with PHE134, PHE 221, and TRP 224, while the steroidal drug exemestane lacked π-stacking interactions. QSAR studies were performed using the flavonoid compounds, in order to identify the structural functionalities needed to improve the anti-breast cancer activity. Molecular dynamics of the screened hits confirmed the stability of compounds with the target in the binding cavity. Moreover, pharmacophore modelling presented the pharmacophoric features of the selected scaffolds for aromatase inhibitory activity.

Conclusion

The results presented 23 hit compounds that can be developed as anti-breast cancer modulating agents in the near future. Additionally, anthraquinone compounds with minor structural modification can also serve to be potential aromatase inhibitors. The in silico protocol utilised can be useful in the drug discovery process for development of new leads from structurally diverse set of natural products that are comparable to the drugs used clinically in breast cancer therapy.

Investigating the superiority of chitosan/D-alpha-tocopheryl polyethylene glycol succinate binary coated bilosomes in promoting the cellular uptake and anti-SARS-CoV-2 activity of polyphenolic herbal drug candidate

The evolution of a safe and effective therapeutic system to conquer SAR-CoV-2 infection deemed to be a crucial worldwide demand. Curcumin (CUR) is a phytomedicinal polyphenolic drug that exhibited a well-reported anti-SAR-CoV-2. However, the therapeutic activity of CUR is hindered by its poor intestinal permeability and diminished aqueous solubility. Therefore, this study strived to develop D-alpha-tocopheryl polyethylene glycol succinate (TPGS) bilosomes (TPGS-Bs) adopting 23 full factorial designs to improve solubility and intestinal permeability of CUR, hence boosting its anti-SARS-CoV-2 activity. Eight experimental runs were attained considering three independent variables: soybean phosphatidylcholine amount (mg) (SPC amount), bile salt amount (mg) (BS amount), and TPGS amount (mg). The optimum formula (F4) exhibited EE % (88.5 ± 2.4 %), PS (181.5 ± 21.6 nm), and ZP (-34.5 ± 3.7 mV) with desirability value = 0.739 was picked as an optimum formula. Furthermore, the optimum formula (F4) was extra coated with chitosan (CS) to improve permeability and anti-SAR-CoV-2 activity. Caco-2 cell uptake after 2 hr revealed the superiority of CS-F4 and F4 by 6 and 5 folds relative to CUR dispersion, respectively. Furthermore, CS-F4 exhibited a significantly higher anti-SARS-CoV-2 activity with IC50 (0.24 µg/ml) by 8.3 times than F4 (1.99 µg/ml). Besides, the mechanistic study demonstrated that the two formulae imparted antiviral activity by inhibiting the spike protein by virucidal potentialities. In addition, the conducted molecular docking and MD simulations towards the SARS-CoV-2 Mpro enzyme confirmed the interaction of CUR with key residues of the virus enzymes. Based on the preceded, CS-F4 could be assumed to be used to effectively eradicate SARS-CoV-2 infection.

Investigation of the phytochemical composition, antioxidant, antibacterial, anti-osteoarthritis, and wound healing activities of selected vegetable waste

Agri-food wastes, produced following industrial food processing, are mostly discarded, leading to environmental hazards and losing the nutritional and medicinal values associated with their bioactive constituents. In this study, we performed a comprehensive analytical and biological evaluation of selected vegetable by-products (potato, onion, and garlic peels). The phytochemical analysis included UHPLC-ESI-qTOF-MS/MS in combination with molecular networking and determination of the total flavonoid and phenolic contents. Further, the antimicrobial, anti-osteoarthritis and wound healing potentials were also evaluated. In total, 47 compounds were identified, belonging to phenolic acids, flavonoids, saponins, and alkaloids as representative chemical classes. Onion peel extract (OPE) showed the higher polyphenolic contents, the promising antioxidant activity, the potential anti-osteoarthritis activity, and promising antimicrobial activity, especially against methicillin-resistant Staphylococcus aureus (MRSA). Furthermore, OPE revealed to have promising in vivo wound healing activity, restoring tissue physiology and integrity, mainly through the activation of AP-1 signaling pathway. Lastly, when OPE was loaded with nanocapsule based hydrogel, the nano-formulation revealed enhanced cellular viability. The affinities of the OPE major metabolites were evaluated against both p65 and ATF-2 targets using two different molecular docking processes revealing quercetin-3,4'-O-diglucoside, alliospiroside C, and alliospiroside D as the most promising entities with superior binding scores. These results demonstrate that vegetable by-products, particularly, those derived from onion peels can be incorporated as natural by-product for future evaluation against wounds and osteoarthritis.

Anticholinesterase and anti-inflammatory constituents from Caralluma awdeliana, a medicinal plant from Yemen

From the dichloromethane (DCM) fraction of the crude ethanolic extract of Caralluma awdeliana, four pregnane glycosides and a flavone glycoside were isolated using a bio-guided isolation approach. The different extracts of C. awdeliana were subjected to in vitro enzyme inhibitory assays of anticholinesterases (AChE and BChE) and anti-inflammatory (COXs and 5-LOX). The highest inhibitory activity was exhibited by DCM fraction against COX-1, COX-2, and 5-LOX with IC₅₀ of 4.8 ± 0.5 μg/mL, 0.68 ± 0.2 μg/mL, and 39.5 ± 3.0 μg/mL, respectively. The DCM showed also a moderate activity against AChE (IC₅₀ 384.72 ± 3.6 μg/mL), and BChE (IC₅₀ 384.72 ± 3.6 μg/mL). The repeated chromatography of DCM fraction resulted in the isolation of two new pregnane glycosides, namely awdeliosides A (1) and B (4), two known ones, namely caratuberosides B and D, along with the known flavone glycoside identified as luteolin 4 -O-neohesperidoside. All the isolated compounds were tested for their in vitro enzyme inhibitory assays. Among the isolated compounds, awdelioside B (4) showed the most potent effect against COX-1 with IC₅₀ value of 10.99 ± 0.35 μM, compared to standard celecoxib (IC₅₀ 230.74 ± 2.62 μM). All the isolated compounds showed weak anticholinesterase, except a moderate activity observed for awdelioside B (4) against BChE with IC₅₀ value of 15.63 ± 3.5 μM, compared to standard donepezil (IC₅₀ 0.77 ± 0.0088 μM).

Identification of Antimicrobial Metabolites from the Egyptian Soil-Derived Amycolatopsis keratiniphila Revealed by Untargeted Metabolomics and Molecular Docking

Actinomycetes are prolific producers of bioactive secondary metabolites. The prevalence of multidrug-resistant (MDR) pathogens has prompted us to search for potential natural antimicrobial agents. Herein, we report the isolation of rare actinobacteria from Egyptian soil. The strain was identified as Amycolatopsis keratiniphila DPA04 using 16S rRNA gene sequencing. Cultivation profiling, followed by chemical and antimicrobial evaluation of crude extracts, revealed the activity of DPA04 ISP-2 and M1 culture extracts against Gram-positive bacteria. Minimum inhibitory concentrations (MIC) values ranged from 19.5 to 39 µg/mL. Chemical analysis of the crude extracts using ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF) led to the identification of 45 metabolites of different chemical classes. In addition, ECO-0501 was identified in the cultures with significant antimicrobial activity. Multidrug resistance in Staphylococcus aureus is reported to be related to the multidrug efflux pump (MATE). ECO-0501 and its related metabolites were subjected to molecular docking studies against the MATE receptor as a proposed mechanism of action. ECO-0501 and its derivatives (AK_1 and N-demethyl ECO-0501) had better binding scores (-12.93, -12.24, and -11.92 kcal/mol) than the co-crystallized 4HY inhibitor (-8.99 kcal/mol) making them promising candidates as MATE inhibitors. Finally, our work established that natural products from this strain could be useful therapeutic tools for controlling infectious diseases.

Cholinesterase Inhibitors from an Endophytic Fungus Aspergillus niveus Fv-er401: Metabolomics, Isolation and Molecular Docking

Alzheimer’s disease poses a global health concern with unmet demand requiring creative approaches to discover new medications. In this study, we investigated the chemical composition and the anticholinesterase activity of Aspergillus niveus Fv-er401 isolated from Foeniculum vulgare (Apiaceae) roots. Fifty-eight metabolites were identified using UHPLC-MS/MS analysis of the crude extract. The fungal extract showed acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory effects with IC50 53.44 ± 1.57 and 48.46 ± 0.41 µg/mL, respectively. Two known metabolites were isolated, terrequinone A and citrinin, showing moderate AChE and BuChE inhibitory activity using the Ellman’s method (IC50 = 11.10 ± 0.38 µg/mL and 5.06 ± 0.15 µg/mL, respectively for AChE, and IC50 15.63 ± 1.27 µg/mL and 8.02 ± 0.08 µg/mL, respectively for BuChE). As evidenced by molecular docking, the isolated compounds and other structurally related metabolites identified by molecular networking had the required structural features for AChE and BuChE inhibition. Where varioxiranol G (−9.76 and −10.36 kcal/mol), penicitrinol B (−9.50 and −8.02 kcal/mol), dicitrinol A (−8.53 and −7.98 kcal/mol) and asterriquinone CT5 (−8.02 and −8.25 kcal/mol) showed better binding scores as AChE and BuChE inhibitors than the co-crystallized inhibitor (between −7.89 and 7.82 kcal/mol) making them promising candidates for the development of new drugs to treat Alzheimer’s.

Metformin ameliorates doxorubicin-induced cardiotoxicity targeting HMGB1/TLR4/NLRP3 signaling pathway in mice

AIMS

Oxidative stress and inflammation have been linked to doxorubicin (DOX)-induced cardiotoxicity, while the exact molecular processes are currently under investigation. The goal of this study is to investigate Metformin's preventive role in cardiotoxicity induced by DOX.

MATERIALS AND METHODS

Male albino mice were divided randomly into 4 groups. Metformin (Met) 200 mg/kg orally (p.o.) was given either alone or when combined with a single DOX (15 mg/kg; i.p.). A control group of 5 mice was also provided. Met was initiated 7 days before DOX, lasting for 14 days. Besides, docking studies of Met towards HMGB1, NF-kB, and caspase 3 were performed.

KEY FINDINGS

Heart weight, cardiac troponin T (cTnT), creatine kinase Myocardial Band (CK-MB) levels, malondialdehyde (MDA), and nitric oxide (NO) contents all increased significantly when comparing the DOX group to the control normal group. Conversely, there was a substantial decline in superoxide dismutase (SOD) and glutathione peroxidase (GSH). DOX group depicts a high expression of TLR4, HMGB1, and caspase 3. Immunohistochemical staining revealed an increase in NLRP3 inflammasome and NF-κB expressions alongside histopathological modifications. Additionally, Met dramatically decreased cardiac weight, CK-MB, and cTnT while maintaining the tissues' histological integrity. Inflammatory biomarkers, including HMGB1, TLR4, NF-κB, inflammasome, and caspase 3 were reduced after Met therapy. Furthermore, molecular docking studies suggested the antagonistic activity of Met towards HMGB1, NF-κB, and caspase 3 target receptors.

SIGNIFICANCE

According to recent evidence, Met is a desirable strategy for improving cardiac toxicity produced by DOX by inhibiting the HMGB1/NF-κB inflammatory pathway, thus preserving heart function.