Exploiting Citrus aurantium seeds and their secondary metabolites in the management of Alzheimer disease

Protective effect of a hydromethanolic extract from Fraxinus excelsior L. bark against a rat model of aluminum chloride-induced Alzheimer's disease: Relevance to its anti-inflammatory and antioxidant effects

ETHNOPHARMACOLOGICAL RELEVANCE

Fraxinus excelsior L. (FE), commonly known as the ash, belongs to the Oleaceae family and has shown several pharmacological and biological properties, such as antioxidant, immunomodulatory, neuroprotective, and anti-inflammatory effects. It has also attracted the most attention toward neuroinflammation. Moreover, FE bark and leaves have been used to treat neurological disorders, aging, neuropathic pain, urinary complaints, and articular pain in traditional and ethnomedicine. Alzheimer's disease (AD) is a multifactorial neurodegenerative disorder resulting from the involvement of amyloid-beta, metal-induced oxidative stress, and neuroinflammation.

AIM OF THE STUDY

The objective of the current study was to assess the neuroprotective effects of hydromethanolic extract from FE bark in an AlCl3-induced rat model of AD.

MATERIALS AND METHODS

The maceration process was utilized to prepare the hydromethanolic extract of FE bark, and characterized by LC-MS/MS. To assess the anti-AD effects of the FE extract, rats were categorized into five different groups, AlCl3; normal control; FE-treated groups at 50, 100, and 200 mg/kg. Passive avoidance learning test, Y-maze, open field, and elevated plus maze behavioral tests were evaluated on days 7 and 14 to analyze the cognitive impairments. Zymography analysis, biochemical tests, and histopathological changes were also followed in different groups.

RESULTS

LC-MS/MS analysis indicated the presence of coumarins, including isofraxidin7-O-diglucoside in the methanolic extract of FE as a new isofraxidin derivative in this genus. FE significantly improved memory and cognitive function, maintained weight, prevented neuronal damages, and preserved the hippocampus's histological features, as demonstrated by behavioral tests and histopathological analysis. FE increased anti-inflammatory MMP-2 activity, whereas it decreased that of inflammatory MMP-9. Moreover, FE increased plasma antioxidant capacity by enhancing CAT and GSH while decreasing nitrite levels in the serum of treated groups. In comparison between the treated groups, the rats that received high doses of the FE extract (200 mg/kg) showed the highest therapeutic effect.

CONCLUSION

FE rich in coumarins could be an effective anti-AD adjunct agent, passing through antioxidant and anti-inflammatory pathways. These results encourage further studies for the development of this extract as a promising agent in preventing, managing, or treating AD and related diseases.

A pharmacological and toxicological biochemical study of cardiovascular regulatory effects of hibiscus, corn silk, marjoram, and chamomile

Hypertension is one of the most typical causes of morbidity and mortality. The present study investigated the possible antihypertensive cardiovascular effects of an herbal mixture extract of Hibiscus, Corn silk, Marjoram, and Chamomile. HPLC analysis of the water extract prepared from the aerial parts of four plants and their mixture was done to detect the most predominant compounds. A safety study was done prior to the efficacy study to determine the dose and ensure the extract's safety in female rats. Hypertension was induced in ovariectomized and non-ovariectomized rats by oral administration of 50 mg/kg of LName for 30 days; the hypertensive rats were classified into non-ovariectomized and ovariectomized untreated groups, treated groups with high and low doses of the mixture(150,300 mg/kg) given to ovariectomized and non-ovariectomized hypertensive groups and a standard group treated with angiotensin-converting enzyme inhibitor. The untreated group showed significant elevation of blood pressure, heart rate, cholesterol, triglycerides, malondialdehyde, cyclic adenosine monophosphate, angiotensin-converting enzyme, C-reactive protein, and significantly lowered reduced glutathione, high-density lipoprotein, and endothelial nitric oxide synthase. Treatment significantly counteracted the effects of L Name. The mixture provides a promising natural cardiovascular regulating supplement owing to its high contents of flavonoids.

Paradigms and Success Stories of Natural Products in Drug Discovery Against Neurodegenerative Disorders (NDDs)

Neurodegenerative disorders (NDDs) are multifaceted complex disorders that have put a great health and economic burden around the globe nowadays. The multi-factorial nature of NDDs has presented a great challenge in drug discovery and continuous efforts are in progress in search of suitable therapeutic candidates. Nature has a great wealth of active principles in its lap that has cured the human population since ancient times. Natural products have revealed several benefits over conventional synthetic medications and scientists have shifted their vision towards exploring the therapeutic potentials of natural products in the past few years. The structural mimicking of natural compounds to endogenous ligands has presented them as a potential therapeutic candidate to prevent the development of NDDs. In the presented review, authors have summarized demographical facts about various NDDs including Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD) and various types of sclerosis in the brain. The significant findings of new active principles of natural origin along with their therapeutic potentials on NDDs have been included. Also, a description of clinical trials and patents on natural products has been enlisted in this compilation. Although natural products have shown promising success in drug discovery against NDDs, still their use is associated with several ethical issues which need to be solved in the upcoming time.

Hesperidin ameliorates benign prostatic hyperplasia by attenuating cell proliferation, inflammatory response, and epithelial-mesenchymal transition via the TGF-β1/Smad signaling pathway

Excessively activated transforming growth factor-beta 1 (TGF-β1) exacerbates benign prostatic hyperplasia (BPH) by triggering epithelial-mesenchymal transition (EMT) as well as epithelial and stromal cell differentiation. Hesperidin (HSP), a flavanone rich in citrus peels, exhibits a safe anti-cancer activity with few side effects. Although HSP reportedly inhibits cell growth in prostate cancer, studies on BPH have not yet been reported. Thus, this study aimed to figure out the therapeutic effect of HSP and its underlying mechanisms in BPH models in vivo and in vitro. To evaluate the anti-BPH effect of HSP in vivo, rats were injected with testosterone propionate (TP; 10 mg/kg, s.c.), finasteride (5 mg/kg, p.o.), and HSP (50 and 100 mg/kg, i.p.) for four weeks. The in vitro efficacy of HSP was evaluated using two prostate cell models, BPH-1 and dihydrotestosterone-stimulated WPMY-1 cells, for studying the interaction between epithelial and stromal cells. Both in vivo and in vitro, HSP inhibited prostate cell proliferation by suppressing the expression of androgen receptor-related markers. In addition, HSP reduced the expression levels of inflammatory and mesenchymal markers by blocking TGF-β1 activation. Collectively, HSP alleviated BPH by attenuating prostate cell proliferation, the inflammatory response, and EMT by regulating the TGF-β1/Smad signaling pathway. Thus, these results provide evidence for a new therapeutic approach against BPH.

Neuroprotective Potentials of Flavonoids: Experimental Studies and Mechanisms of Action

Neurological and neurodegenerative diseases, particularly those related to aging, are on the rise, but drug therapies are rarely curative. Functional disorders and the organic degeneration of nervous tissue often have complex causes, in which phenomena of oxidative stress, inflammation and cytotoxicity are intertwined. For these reasons, the search for natural substances that can slow down or counteract these pathologies has increased rapidly over the last two decades. In this paper, studies on the neuroprotective effects of flavonoids (especially the two most widely used, hesperidin and quercetin) on animal models of depression, neurotoxicity, Alzheimer's disease (AD) and Parkinson's disease are reviewed. The literature on these topics amounts to a few hundred publications on in vitro and in vivo models (notably in rodents) and provides us with a very detailed picture of the action mechanisms and targets of these substances. These include the decrease in enzymes that produce reactive oxygen and ferroptosis, the inhibition of mono-amine oxidases, the stimulation of the Nrf2/ARE system, the induction of brain-derived neurotrophic factor production and, in the case of AD, the prevention of amyloid-beta aggregation. The inhibition of neuroinflammatory processes has been documented as a decrease in cytokine formation (mainly TNF-alpha and IL-1beta) by microglia and astrocytes, by modulating a number of regulatory proteins such as Nf-kB and NLRP3/inflammasome. Although clinical trials on humans are still scarce, preclinical studies allow us to consider hesperidin, quercetin, and other flavonoids as very interesting and safe dietary molecules to be further investigated as complementary treatments in order to prevent neurodegenerative diseases or to moderate their deleterious effects.

Neuroprotective Effects of Agri-Food By-Products Rich in Phenolic Compounds

Neurodegenerative diseases are known for their wide range of harmful conditions related to progressive cell damage, nervous system connections and neuronal death. These pathologies promote the loss of essential motor and cognitive functions, such as mobility, learning and sensation. Neurodegeneration affects millions of people worldwide, and no integral cure has been created yet. Here, bioactive compounds have been proven to exert numerous beneficial effects due to their remarkable bioactivity, so they could be considered as great options for the development of new neuroprotective strategies. Phenolic bioactives have been reported to be found in edible part of plants; however, over the last years, a large amount of research has focused on the phenolic richness that plant by-products possess, which sometimes even exceeds the content in the pulp. Thus, their possible application as an emergent neuroprotective technique could also be considered as an optimal strategy to revalorize these agricultural residues (those originated from plant processing). This review aims to summarize main triggers of neurodegeneration, revise the state of the art in plant extracts and their role in avoiding neurodegeneration and discuss how their main phenolic compounds could exert their neuroprotective effects. For this purpose, a diverse search of studies has been conducted, gathering a large number of papers where by-products were used as strong sources of phenolic compounds for their neuroprotective properties. Finally, although a lack of investigation is quite remarkable and greatly limits the use of these compounds, phenolics remain attractive for research into new multifactorial anti-neurodegenerative nutraceuticals.

Non-Enzymatic Antioxidants against Alzheimer's Disease: Prevention, Diagnosis and Therapy

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by progressive memory loss and cognitive decline. Although substantial research has been conducted to elucidate the complex pathophysiology of AD, the therapeutic approach still has limited efficacy in clinical practice. Oxidative stress (OS) has been established as an early driver of several age-related diseases, including neurodegeneration. In AD, increased levels of reactive oxygen species mediate neuronal lipid, protein, and nucleic acid peroxidation, mitochondrial dysfunction, synaptic damage, and inflammation. Thus, the identification of novel antioxidant molecules capable of detecting, preventing, and counteracting AD onset and progression is of the utmost importance. However, although several studies have been published, comprehensive and up-to-date overviews of the principal anti-AD agents harboring antioxidant properties remain scarce. In this narrative review, we summarize the role of vitamins, minerals, flavonoids, non-flavonoids, mitochondria-targeting molecules, organosulfur compounds, and carotenoids as non-enzymatic antioxidants with AD diagnostic, preventative, and therapeutic potential, thereby offering insights into the relationship between OS and neurodegeneration.

Can natural products modulate cytokine storm in SARS-CoV2 patients?

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Immune reaction CoV2 can cause uncontrolled systemic inflammatory responses called cytokine storm.

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Medicinal plants and their secondary metabolites are potential modulators of cytokine storm.

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Secondary metabolites modulate inflammatory signaling associated with CoV2.

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The potential applicability of natural products against CoV2 need to be evaluated in strictly defined clinical research.

Currently, the number of cases and deaths of SARS-CoV2, especially among the chronic disease groups, due to aggressive SARS-CoV2 infection is increasing day by day. Various infections, particularly viral ones, cause a cytokine storm resulting in shortness of breath, bleeding, hypotension, and ultimately multi-organ failure due to over-expression of certain cytokines and necrosis factors. The most prominent clinical feature of SARS-CoV2 is the presence of elevated proinflammatory cytokines in the serum of patients with SARS-CoV2. Severe cases exhibit higher levels of cytokines, leading to a “cytokine storm” that further increases disease severity and causes acute respiratory distress syndrome, multiple organ failure, and death. Therefore, targeted cytokine production could be a potential therapeutic option for patients severely infected with SARS-CoV2.

Given the current scenario, great scientific progress has been made in understanding the disease and its forms of treatment. Because of natural ingredients properties, they have the potential to be used as potential agents with the ability to modulate immune responses. Moreover, they can be used safely because they have no toxic effects, are biodegradable and biocompatible. However, these natural substances can continue to be used in the development of new therapies and vaccines.

Finally, the aim and approach of this review article is to highlight current research on the possible use of natural products with promising potential as immune response activators. Moreover, consider the expected use of natural products when developing potential therapies and vaccines.

Biochemical and pharmacological prospects of Citrus sinensis peel

Gastric ulcer and hepatotoxicity due to irrational drug overuse are two of the most serious conditions associated with inflammation and oxidative stress that affect the digestive system. This study aimed to experimentally evaluate the hepatoprotective/gastroprotective effects of aqueous and butanol citrus peel extracts and hesperidin in rat models of ulcer and hepatotoxicity. Acute toxicity study was performed for determining the safe dose of citrus extracts to analyze efficacy. In the experiments on hepatoprotective and gastroprotective effects, rats were classified into nine groups in each experiment: (1) negative control, (2) positive control hepatotoxic model with paracetamol (640 mg/kg)/gastric ulcer model:ethanol 70% (1 ml), (3)reference hepatoprotective:silymarin (25 mg/kg)/gastroprotective:ranitidine (50 mg/kg), and (4-9) groups treated for 2 weeks before induction of each disease with either citrus aqueous or butanol extracts or hesperidin (125-250 mg/kg). Drugs, ethanol, or tested compounds were administered orally. The levels of biochemical parameters, such as AST, ALT, NO, MDA, CRP, and ILβ6, were significantly reduced, but CAT level was increased. Postmortem examination of liver and stomach tissues of treated animals revealed marked improvement compared with positive control animals. Hesperidin exerted the best hepatoprotective, antioxidant, anti-inflammatory, and gastroprotective effects, followed by butanol and then aqueous citrus peel extracts.

Pharmacological and metabolomic profiles of Musa acuminata wastes as a new potential source of anti-ulcerative colitis agents

Musa acuminata (MA) is a popular fruit peels in the world. Non-food parts of the plant have been investigated for their antioxidant and anti-ulcerative colitis activity. Metabolomic approaches were found to be informative as a screening tool. It discovered different metabolites depending on statistical analysis. The antioxidant activity content was measured by colorimetric method. Seventy six investigated metabolites were observed. The identities of some of these markers were confirmed based on their MS² fragmentation and NMR spectroscopy. These include: cinnamic acid and its dimer 2-hydroxy-4-(4-methoxyphenyl)-1H-phenalen-1-one beside; gallic acid and flavonoids; quercetin, quercetin-3-O-β-d-glucoside, luteolin-7-O-β-d-glucopyranoside. GC/MS analysis of MA peels essential oil led to identification of 37 compounds. The leaves, pseudostem and fruit peels extracts were tested for their safety and their anti-ulcerative colitis efficacy in rats. Rats were classified into: normal, positive, prednisolone reference group, MA extracts pretreated groups (250–500 mg/kg) for 2 weeks followed by induction of ulcerative colitis by per-rectal infusion of 8% acetic acid. Macroscopic and microscopic examinations were done. Inflammatory markers (ANCA, CRP and Ilβ6) were measured in sera. The butanol extracts showed good antioxidant and anti-inflammatory activities as they ameliorated macroscopic and microscopic signs of ulcerative colitis and lowered the inflammatory markers compared to untreated group. MA wastes can be a potential source of bioactive metabolites for industrial use and future employment as promising anti-ulcerative colitis food supplements.

An ethnopharmacological review on the therapeutical properties of flavonoids and their mechanisms of actions: A comprehensive review based on up to date knowledge

Flavonoids -a class of low molecular weight secondary metabolites- are ubiquitous and cornucopia throughout the plant kingdom. Structurally, the main structure consists of C6-C3-C6 rings with different substitution patterns so that many sub-classes are obtained, for example: flavonols, flavonolignans, flavonoid glycosides, flavans, anthocyanidins, aurones, anthocyanidins, flavones, neoflavonoids, chalcones, isoflavones, flavones and flavanones. Flavonoids are evaluated to have drug like nature since they possess different therapeutic activities, and can act as cardioprotective, antiviral, antidiabetic, anti-inflammatory, antibacterial, anticancer, and also work against Alzheimer's disease and others. However, information on the relationship between their structure and biological activity is scarce. Therefore, the present review tries to summarize all the therapeutic activities of flavonoids, their mechanisms of action and the structure activity relationship.

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Latest updated ethnopharmacological review of the therapeutic effects of flavonoids.

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Flavonoids are attracting attention because of their therapeutic properties.

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Flavonoids are valuable candidates for drug development against many dangerous diseases.

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This overview summarizes the most important therapeutic effect and mechanism of action of flavonoids.

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General knowledge about the structure activity relationship of flavonoids is summarized.

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Substitution of chemical groups in the structure of flavonoids can significantly change their biological and chemical properties.

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The chemical properties of the basic flavonoid structure should be considered in a drug-based structural program.

The Potential Synergistic Activity of Zolmitriptan Combined in New Self-Nanoemulsifying Drug Delivery Systems: ATR-FTIR Real-Time Fast Dissolution Monitoring and Pharmacodynamic Assessment

Purpose

The current work aimed to overcome the poor permeability and undesirable adverse effects of Zolmitriptan (ZMT) and to increase its efficacy in the treatment of acute migraine by exploiting the synergistic effect of the essential oil, lavender, to fabricate ZMT self-nanoemulsifying drug delivery systems (ZMT-SNEDDS).

Methods

ZMT-SNEDDS were fabricated based on full factorial design (3²) to statistically assess the impact of oil and surfactant concentrations on the nanoemulsion globule size, zeta potential and percentage drug dissolution efficiency. An ATR-FTIR method was developed and validated for continuous real-time monitoring of ZMT dissolution and permeation. The dose of the optimized ZMT-SNEDDS used in the efficacy study was selected according to the acute toxicity study. The efficacy study was performed on migraineous rats induced by nitroglycerin and was evaluated by the activity cage and thermal tests, electroencephalogram, electroconvulsive stimulation, and biochemical analysis of brain tissue. Finally, histopathological and immunohistochemical examinations of the cerebra were carried out.

Results

Upon dilution, the optimized ZMT-SNEDDS (F5) exhibited nanosized spherical droplets of 19.59±0.17 nm with narrow size distribution, zeta potential (-23.5±1.17mV) and rapid emulsification characteristics. ATR-FTIR spectra elucidated the complete time course of dissolution and permeation, confirming F5 superior performance. Moreover, ZMT-SNEDDS (F5) showed safety in an acute toxicity study. ZMT concentration in rat brain tissues derived from F5 was lower compared to that of ZMT solution, yet its effect was better on the psychological state, algesia, as well as maintaining normal brain electrical activity and delayed convulsions. It counteracted the cerebral biochemical alternations induced by nitroglycerin, which was confirmed by histopathological examination.

Conclusion

In a nutshell, these findings corroborated the remarkable synergistic efficacy and the high potency of lavender oil-based ZMT-SNEDDS in migraine management compared to the traditional zolmitriptan solution.

Citrus aurantium L. Active Constituents, Biological Effects and Extraction Methods. An Updated Review

Citrus genus is a prominent staple crop globally. Long-term breeding and much hybridization engendered a myriad of species, each characterized by a specific metabolism generating different secondary metabolites. Citrus aurantium L., commonly recognized as sour or bitter orange, can exceptionally be distinguished from other Citrus species by unique characteristics. It is a fruit with distinctive flavor, rich in nutrients and phytochemicals which possess different health benefits. This paper presents an overview of the most recent studies done on the matter. It intends to provide an in-depth understanding of the biological activities and medicinal uses of active constituents existing in C. aurantium. Every plant part is first discussed separately with regards to its content in active constituents. All extraction methods, their concepts and yields, used to recover these valuable molecules from their original plant matrix are thoroughly reported.

Acetylcholinesterase Inhibitors in the Treatment of Neurodegenerative Diseases and the Role of Acetylcholinesterase in their Pathogenesis

Acetylcholinesterase (AChE) plays an important role in the pathogenesis of neurodegenerative diseases by influencing the inflammatory response, apoptosis, oxidative stress and aggregation of pathological proteins. There is a search for new compounds that can prevent the occurrence of neurodegenerative diseases and slow down their course. The aim of this review is to present the role of AChE in the pathomechanism of neurodegenerative diseases. In addition, this review aims to reveal the benefits of using AChE inhibitors to treat these diseases. The selected new AChE inhibitors were also assessed in terms of their potential use in the described disease entities. Designing and searching for new drugs targeting AChE may in the future allow the discovery of therapies that will be effective in the treatment of neurodegenerative diseases.

Antiviral activity of Lavandula angustifolia L. and Salvia officinalis L. essential oils against avian influenza H5N1 virus

Nowadays, viral infection is considered a major cause of mortality all over the world such as covid-19 pandemic. In this context, searching for antiviral agents are major researchers interests. In this study, essential oils (EO) of Lavandula angustifolia (lavender) and Salvia officinalis (salvia) were subjected to combat avian influenza H5N1 virus. Laboratory trials were performed to identify Lavender and salvia EOs and evaluate their antioxidant, anti-inflammatory and antiviral activity against an avian influenza H5N1 virus. EOs were prepared by the hydrodistillation of air-dried plants and analyzed by GC-MS methods. The results revealed that salvia has the highest EOs yield 1.3% than lavender 1%. The dominant constituents of lavender EO were linalyl acetate and linalool while camphor and α-thujone were the dominant compounds of salvia. Both oils exhibited antioxidant activity in DPPH and ABTS and total antioxidant capacity assays. The results suggest the use of salvia and lavender EOs as effective natural anti-inflammatory, antioxidant and antiviral agents.

New designer phenethylamines 2C-C and 2C-P have abuse potential and induce neurotoxicity in rodents

2C (2C-x) is the general name for the family of phenethylamines containing two methoxy groups at the 2 and 5 positions of the benzene ring. The abuse of 2C family drugs has grown rapidly, although the abuse potential and neurotoxic properties of 2C drugs have not yet been fully investigated. In this study, we investigated the abuse potential and neurotoxicity of 4-chloro-2,5-dimethoxyphenethylamine (2C-C) and 2,5-dimethoxy-4-propylphenethylamine (2C-P). We found that 2C-C and 2C-P produced conditioned place preference in a dose-dependent manner in mice, and increased self-administration in rats, suggesting that 2C-C and 2C-P have abuse potential. To investigate the neurotoxicity of 2C-C and 2C-P, we examined motor performance and memory impairment after high doses of 2C-C and 2C-P. High doses of 2C-C and 2C-P decreased locomotor activity, rota-rod performance, and lower Y-maze test, novel objective recognition test, and passive avoidance test scores. We also observed that 2C-C and 2C-P affected expression levels of the D1 dopamine receptor, D2 dopamine receptor, dopamine transporter, and phospho-dopamine transporter in the nucleus accumbens and the medial prefrontal cortex, and increased c-Fos immuno-positive cells in the nucleus accumbens. Moreover, high doses of 2C-C and 2C-P induced microglial activation, which is involved in the inflammatory reaction in the striatum. These results suggest that 2C-C and 2C-P have abuse potential by affecting dopaminergic signaling and induce neurotoxicity via initiating neuroinflammation at high doses.

Cytotoxicity and antimicrobial efficiency of selenium nanoparticles biosynthesized by Spirulina platensis

Nanotechnology has been exploited as a great scientific area especially in stating scenarios in drug discovery. In the present study, biosynthesized selenium nanoparticles (SeNPs) were prepared by the filtrate of Spirulina platensis after ultrasonication of their biomass. The biosynthesized SeNPs was characterized by using ultra-violet visible, Fourier transform infra-red spectroscopy, dynamic light scattering, and transmission electron microscope (TEM). The zeta potential of Biogenic SeNPs was -32.9 ± 8.12 mv that caused their stability. TEM micrographs elucidated the spherical shape of Biogenic SeNPs with a mean average size of 79.40 ± 44.26 nm. Biogenic SeNPs showed potential antimicrobial activity against gram-negative bacteria and yeast fungi C. albicans ATCC10231. No toxic effect was observed for SeNPs on normal kidney and liver cell lines. Biogenic SeNPs could be considered as a hopeful choice for future therapeutic applications because of their good biocompatibility and reactivity.