Effects of the Aphanizomenon flos-aquae Extract (Klamin®) on a Neurodegeneration Cellular Model

Attention-deficit/hyperactivity disorder and inflammation: natural product-derived treatments-a review of the last ten years

OBJECTIVE

Attention-deficit hyperactivity disorder (ADHD) is a psychiatric disorder characterized by symptoms of inattention, hyperactivity, and impulsivity. Stimulant medication is the main pharmacological treatment for ADHD. However, the traditional pharmacological treatments may have significant side effects; therefore, non-pharmacological approaches are needed. Thus, there has been growing interest in alternative herbal treatments. The aim of this review was to comprehensively assess the current evidence for plant-based treatment of ADHD in human and animal models, as well as their ability to modulate the inflammatory process.

METHODS

This study was an integrative review of the current evidence for the plant-based treatment of ADHD. The research involved using literature available on PubMed and Scopus databases.

FINDINGS

Spontaneously hypersensitive rats treated with baicalin exhibited significant reductions in locomotion, increased spatial learning skills, and increased levels of dopamine in the striatum. Supplementation with Sansonite improved memory and attention capacity. In human studies, Ginkgo biloba significantly improved the symptoms of inattention and reduced memory impairment. In studies conducted using Korean Red ginseng, Klamath, and Crocus sativus L., the patients showed significant improvements in symptoms of inattention and hyperactivity/impulsivity. Furthermore, we demonstrated that the identified plants modulate the inflammatory process through pro-inflammatory and anti-inflammatory cytokines, nitric oxide, Th cells, Toll-like receptor 4, and mitogen-activated protein kinases.

CONCLUSION

All the studies included in this review focused on plants with demonstrated potential against inflammatory processes, positioning them as promising candidates for ADHD treatment, due to their potential to attenuate or even prevent neuroinflammatory mechanisms.

Uqcr11 alleviates oxidative stress and apoptosis after traumatic brain injury

Traumatic brain injury (TBI) is a major cause of death and disability that involves brain dysfunction due to external forces. Here, we found lower levels of Ubiquinol-cytochrome c reductase, complex III subunit XI (Uqcr11) expression in the cerebral cortex of TBI mice. A neuronal damage model was constructed using H2O2 or hypoxia reoxygenation (H/R) in vitro. We found that Uqcr11 overexpression attenuated the H2O2-or H/R-induced damage by preventing oxidative stress and neuronal apoptosis in HT22 cells. Moreover, up-regulated Uqcr11 contributed to the restoration of motor, learning, and memory in C57BL/6 mice after TBI, and its underlying mechanism may be associated with promoting neuron survival and inhibited oxidative stress. Collectively, our findings demonstrated that oxidative stress as well as neuronal apoptosis can be ameliorated post-TBI by Uqcr11 overexpression, which provides a potential therapeutic target for TBI.

Positive Impacts of Aphanizomenon Flos Aquae Extract on Obesity-Related Dysmetabolism in Mice with Diet-Induced Obesity

The present study evaluated the ability of KlamExtra®, an Aphanizomenon flos aquae (AFA) extract, to counteract metabolic dysfunctions due to a high fat diet (HFD) or to accelerate their reversion induced by switching an HFD to a normocaloric diet in mice with diet-induced obesity. A group of HFD mice was fed with an HFD supplemented with AFA (HFD-AFA) and another one was fed with regular chow (standard diet-STD) alone or supplemented with AFA (STD-AFA). AFA was able to significantly reduce body weight, hypertriglyceridemia, liver fat accumulation and adipocyte size in HFD mice. AFA also reduced hyperglycaemia, insulinaemia, HOMA-IR and ameliorated the glucose tolerance and the insulin response of obese mice. Furthermore, in obese mice AFA normalised the gene and the protein expression of factors involved in lipid metabolism (FAS, PPAR-γ, SREBP-1c and FAT-P mRNA), inflammation (TNF-α and IL-6 mRNA, NFkB and IL-10 proteins) and oxidative stress (ROS levels and SOD activity). Interestingly, AFA accelerated the STD-induced reversion of glucose dysmetabolism, hepatic and VAT inflammation and oxidative stress. In conclusion, AFA supplementation prevents HFD-induced dysmetabolism and accelerates the STD-dependent recovery of glucose dysmetabolism by positively modulating oxidative stress, inflammation and the expression of the genes linked to lipid metabolism.

Stalling the Course of Neurodegenerative Diseases: Could Cyanobacteria Constitute a New Approach toward Therapy?

Neurodegenerative diseases (NDs) are characterized by progressive and irreversible neuronal loss, accompanied by a range of pathological pathways, including aberrant protein aggregation, altered energy metabolism, excitotoxicity, inflammation, and oxidative stress. Some of the most common NDs include Alzheimer's Disease (AD), Parkinson's Disease (PD), Multiple Sclerosis (MS), Amyotrophic Lateral Sclerosis (ALS), and Huntington's Disease (HD). There are currently no available cures; there are only therapeutic approaches that ameliorate the progression of symptoms, which makes the search for new drugs and therapeutic targets a constant battle. Cyanobacteria are ancient prokaryotic oxygenic phototrophs whose long evolutionary history has resulted in the production of a plethora of biomedically relevant compounds with anti-inflammatory, antioxidant, immunomodulatory, and neuroprotective properties, that can be valuable in this field. This review summarizes the major NDs and their pathophysiology, with a focus on the anti-neurodegenerative properties of cyanobacterial compounds and their main effects.

Aphanizomenon flos-aquae (AFA) Extract Prevents Neurodegeneration in the HFD Mouse Model by Modulating Astrocytes and Microglia Activation

Obesity and related metabolic dysfunctions are associated with neurodegenerative diseases, such as Alzheimer's disease. Aphanizomenon flos-aquae (AFA) is a cyanobacterium considered a suitable supplement for its nutritional profile and beneficial properties. The potential neuroprotective effect of an AFA extract, commercialized as KlamExtra^®, including the two AFA extracts Klamin^® and AphaMax^®, in High-Fat Diet (HFD)-fed mice was explored. Three groups of mice were provided with a standard diet (Lean), HFD or HFD supplemented with AFA extract (HFD + AFA) for 28 weeks. Metabolic parameters, brain insulin resistance, expression of apoptosis biomarkers, modulation of astrocytes and microglia activation markers, and Aβ deposition were analyzed and compared in the brains of different groups. AFA extract treatment attenuated HFD-induced neurodegeneration by reducing insulin resistance and loss of neurons. AFA supplementation improved the expression of synaptic proteins and reduced the HFD-induced astrocytes and microglia activation, and Aβ plaques accumulation. Together, these outcomes indicate that regular intake of AFA extract could benefit the metabolic and neuronal dysfunction caused by HFD, decreasing neuroinflammation and promoting Aβ plaques clearance.

A potential host and virus targeting tool against COVID-19: Chemical characterization, antiviral, cytoprotective, antioxidant, respiratory smooth muscle relaxant effects of Paulownia tomentosa Steud

COronaVIrus Disease 2019 (COVID-19) is a newly emerging infectious disease that spread across the world, caused by the novel coronavirus Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2). Despite the advancements in science that led to the creation of the vaccine, there is still an urgent need for new antiviral drugs effective against SARS-CoV-2. This study aimed to investigate the antiviral effect of Paulownia tomentosa Steud extract against SARS-CoV-2 and to evaluate its antioxidant properties, including respiratory smooth muscle relaxant effects. Our results showed that P. tomentosa extract can inhibit viral replication by directly interacting with both the 3-chymotrypsin-like protease and spike protein. In addition, the phyto complex does not reduce lung epithelial cell viability and exerts a protective action in those cells damaged by tert-butyl hydroperoxide , a toxic agent able to alter cells' functions via increased oxidative stress. These data suggest the potential role of P. tomentosa extract in COVID-19 treatment, since this extract is able to act both as an antiviral and a cytoprotective agent in vitro.

Nutritional epigenomic and DNA-damage modulation effect of natural stilbenoids

The aim of the present work is the evaluation of biological effects of natural stilbenoids found in Vitis vinifera, with a focus on their activity as epigenetic modulators. In the present study, resveratrol, pterostilbene and for the first time their dimers (±)-trans-δ-viniferin, (±)-trans-pterostilbene dehydrodimer were evaluated in Caco-2 and HepG-2 cell lines as potential epigenetic modulators. Stilbenoids were added in a Caco-2 cell culture as a model of the intestinal epithelial barrier and in the HepG-2 as a model of hepatic environment, to verify their dose-dependent toxicity, ability to interact with DNA, and epigenomic action. Resveratrol, pterostilbene, and (±)-trans-pterostilbene dehydrodimer were found to have no toxic effects at tested concentration and were effective in reversing arsenic damage in Caco-2 cell lines. (±)-trans-δ-viniferin showed epigenomic activity, but further studies are needed to clarify its mode of action.

Flow Synthesis of Nature-Inspired Mitochondria-Targeted Phenolic Derivatives as Potential Neuroprotective Agents

A series of phenolic derivatives designed to selectively target mitochondria were synthesized under flow conditions starting from natural phenolic acids. The two-step continuous flow protocol, performed in Cyrene, a bioavailable dipolar aprotic solvent, allowed the isolation of the MITO compounds in moderate to good yields. The MITO compounds obtained, as a first step, were tested for their safety by cell viability analysis. The cytocompatible dose, in human neuronal cell line SH-SH5Y, depends on the type of compound and the non-toxic dose is between 3.5 and 125 µM. Among the seven MITO compounds synthesized, two of them have shown interesting performances, being able to protect mitochondria from oxidative insult.

Potential Psychoactive Effects of Microalgal Bioactive Compounds for the Case of Sleep and Mood Regulation: Opportunities and Challenges

Sleep deficiency is now considered an emerging global epidemic associated with many serious health problems, and a major cause of financial and social burdens. Sleep and mental health are closely connected, further exacerbating the negative impact of sleep deficiency on overall health and well-being. A major drawback of conventional treatments is the wide range of undesirable side-effects typically associated with benzodiazepines and antidepressants, which can be more debilitating than the initial disorder. It is therefore valuable to explore the efficiency of other remedies for complementarity and synergism with existing conventional treatments, leading to possible reduction in undesirable side-effects. This review explores the relevance of microalgae bioactives as a sustainable source of valuable phytochemicals that can contribute positively to mood and sleep disorders. Microalgae species producing these compounds are also catalogued, thus creating a useful reference of the state of the art for further exploration of this proposed approach. While we highlight possibilities awaiting investigation, we also identify the associated issues, including minimum dose for therapeutic effect, bioavailability, possible interactions with conventional treatments and the ability to cross the blood brain barrier. We conclude that physical and biological functionalization of microalgae bioactives can have potential in overcoming some of these challenges.

Insulin and Its Key Role for Mitochondrial Function/Dysfunction and Quality Control: A Shared Link between Dysmetabolism and Neurodegeneration

Insulin was discovered and isolated from the beta cells of pancreatic islets of dogs and is associated with the regulation of peripheral glucose homeostasis. Insulin produced in the brain is related to synaptic plasticity and memory. Defective insulin signaling plays a role in brain dysfunction, such as neurodegenerative disease. Growing evidence suggests a link between metabolic disorders, such as diabetes and obesity, and neurodegenerative diseases, especially Alzheimer's disease (AD). This association is due to a common state of insulin resistance (IR) and mitochondrial dysfunction. This review takes a journey into the past to summarize what was known about the physiological and pathological role of insulin in peripheral tissues and the brain. Then, it will land in the present to analyze the insulin role on mitochondrial health and the effects on insulin resistance and neurodegenerative diseases that are IR-dependent. Specifically, we will focus our attention on the quality control of mitochondria (MQC), such as mitochondrial dynamics, mitochondrial biogenesis, and selective autophagy (mitophagy), in healthy and altered cases. Finally, this review will be projected toward the future by examining the most promising treatments that target the mitochondria to cure neurodegenerative diseases associated with metabolic disorders.

Microalgae as a Potential Source of Bioactive Food Compounds

Microalgae are unicellular, photosynthethic organisms that can grow on diverse aquatic habitatss like ponds, lakes, rivers, oceans, waste water and humid soils. Recently, microalgae are gaining importance as renewable sources of biologically active food compounds such as polysaccharides, proteins, essential fatty acids, biopigments such as chlorophylls, carotenoids, astaxanthin, as well as vitamins and minerals.The bioactive food compounds of microalgae enable them to be part of multitude of applications in numerous industrial products for healthy life and ecosystem. This review article summarizes the applications of biologically active food compounds derived from microalgae as nutraceuticals, healthy dietary supplements, pharmaceuticals and cosmetics. Further, this review article highlights the importance of research focus on the identification and extraction of bioactive food compounds from the huge numbers of microlage that exist in nature for sustainable global food security and economy.

Antioxidant Activity of Citrus Limonoids and Investigation of Their Virucidal Potential against SARS-CoV-2 in Cellular Models

The COVID-19 pandemic represents an unprecedented global emergency. Despite all efforts, COVID-19 remains a threat to public health, due to the complexity of mass vaccination programs, the lack of effective drugs, and the emergence of new variants. A link has recently been found between the risk of developing a severe COVID-19 infection and a high level of oxidative stress. In this context, we have focused our attention on natural compounds with the aim of finding molecules capable of acting through a dual virucidal–antioxidant mechanism. In particular, we studied the potential of grapefruit seed extracts (GSE) and their main components, belonging to the class of limonoids. Using chemical and biological approaches including isolation and purification of GSE, antioxidant and virucidal assays, we have shown that grapefruit seed constituents, belonging to the class of limonoids, are endowed with remarkable virucidal, antioxidant and mitoprotective activity.

Spasmolytic Effects of Aphanizomenon Flos Aquae (AFA) Extract on the Human Colon Contractility

The blue-green algae Aphanizomenon flos aquae (AFA), rich in beneficial nutrients, exerts various beneficial effects, acting in different organs including the gut. Klamin^® is an AFA extract particularly rich in β-PEA, a trace-amine considered a neuromodulator in the central nervous system. To date, it is not clear if β-PEA exerts a role in the enteric nervous system. The aims of the present study were to investigate the effects induced by Klamin^® on the human distal colon mechanical activity, to analyze the mechanism of action, and to verify a β-PEA involvement. The organ bath technique, RT-PCR, and immunohistochemistry (IHC) were used. Klamin^® reduced, in a concentration-dependent manner, the amplitude of the spontaneous contractions. EPPTB, a trace-amine receptor (TAAR1) antagonist, significantly antagonized the inhibitory effects of both Klamin^® and exogenous β-PEA, suggesting a trace-amine involvement in the Klamin^® effects. Accordingly, AphaMax^®, an AFA extract containing lesser amount of β-PEA, failed to modify colon contractility. Moreover, the Klamin^® effects were abolished by tetrodotoxin, a neural blocker, but not by L-NAME, a nitric oxide-synthase inhibitor. On the contrary methysergide, a serotonin receptor antagonist, significantly antagonized the Klamin^® effects, as well as the contractility reduction induced by 5-HT. The RT-PCR analysis revealed TAAR1 gene expression in the colon and the IHC experiments showed that 5-HT-positive neurons are co-expressed with TAAR1 positive neurons. In conclusion, the results of this study suggest that Klamin^® exerts spasmolytic effects in human colon contractility through β-PEA, that, by activating neural TAAR1, induce serotonin release from serotoninergic neurons of the myenteric plexus.

Protective, Antioxidant and Antiproliferative Activity of Grapefruit IntegroPectin on SH-SY5Y Cells

Tested in vitro on SH-SY5Y neuroblastoma cells, grapefruit IntegroPectin is a powerful protective, antioxidant and antiproliferative agent. The strong antioxidant properties of this new citrus pectin, and its ability to preserve mitochondrial membrane potential and morphology, severely impaired in neurodegenerative disorders, make it an attractive therapeutic and preventive agent for the treatment of oxidative stress-associated brain disorders. Similarly, the ability of this pectic polymer rich in RG-I regions, as well as in naringin, linalool, linalool oxide and limonene adsorbed at the outer surface, to inhibit cell proliferation or even kill, at high doses, neoplastic cells may have opened up new therapeutic strategies in cancer research. In order to take full advantage of its vast therapeutic and preventive potential, detailed studies of the molecular mechanism involved in the antiproliferative and neuroprotective of this IntegroPectin are urgently needed.

Bridging Cyanobacteria to Neurodegenerative Diseases: A New Potential Source of Bioactive Compounds against Alzheimer's Disease

Neurodegenerative diseases (NDs) represent a drawback in society given the ageing population. Dementias are the most prevalent NDs, with Alzheimer’s disease (AD) representing around 70% of all cases. The current pharmaceuticals for AD are symptomatic and with no effects on the progression of the disease. Thus, research on molecules with therapeutic relevance has become a major focus for the scientific community. Cyanobacteria are a group of photosynthetic prokaryotes rich in biomolecules with confirmed activity in pathologies such as cancer, and with feasible potential in NDs such as AD. In this review, we aimed to compile the research works focused in the anti-AD potential of cyanobacteria, namely regarding the inhibition of the enzyme β-secretase (BACE1) as a fundamental enzyme in the generation of β-amyloid (Aβ), the inhibition of the enzyme acetylcholinesterase (AChE) lead to an increase in the availability of the neurotransmitter acetylcholine in the synaptic cleft and the antioxidant and anti-inflammatory effects, as phenomena associated with neurodegeneration mechanisms.

New Neuroprotective Effect of Lemon IntegroPectin on Neuronal Cellular Model

Lemon IntegroPectin obtained via hydrodynamic cavitation of organic lemon processing waste in water shows significant neuroprotective activity in vitro, as first reported in this study investigating the effects of both lemon IntegroPectin and commercial citrus pectin on cell viability, cell morphology, reactive oxygen species (ROS) production, and mitochondria perturbation induced by treatment of neuronal SH-SY5Y human cells with H2O2. Mediated by ROS, including H2O2 and its derivatives, oxidative stress alters numerous cellular processes, such as mitochondrial regulation and cell signaling, propagating cellular injury that leads to incurable neurodegenerative diseases. These results, and the absence of toxicity of this new pectic substance rich in adsorbed flavonoids and terpenes, suggest further studies to investigate its activity in preventing, retarding, or even curing neurological diseases.

Chlorogenic Acid Alleviates Aβ25-35-Induced Autophagy and Cognitive Impairment via the mTOR/TFEB Signaling Pathway

Purpose

Chlorogenic acid (CGA), a phenolic acid isolated from fruits and vegetables, has been established to have neuroprotective properties in relation to Alzheimer's disease (AD). However, the precise mechanism by which CGA prevents cognitive deficits in AD has not been well studied. This study aimed to explore the potential molecular mechanism of CGA action using an Aβ_25-35-induced SH-SY5Y neuron injury and cogxnitive deficits model in APP/PS1 mice.

Methods

Three-month-old male APP/PS1 double transgenic mice and a human neuroblastoma cell line (SH-SY5Y) were used to assess the effects of CGA on AD in vivo and in vitro, respectively. Cognitive function in mice was measured using a Morris water maze (MWM) test. Hematoxylin and eosin, monodansylcadaverine fluorescence, LysoTracker Red (LTR), and immunofluorescence staining were used to evaluate the morphological changes in vivo and in vitro. The protein expressions of autophagy markers (LC3B-II/LC3B-I, p62/SQSTM, beclin1 and Atg5) and lysosomal-function-related markers (cathepsin D, mTOR, p-mTOR P70S6K, p-p70s6k and TFEB) were analyzed with Western blot analyses.

Results

CGA treatment significantly improved spatial memory, relieved neuron damage, and inhibited autophagy in APP/PS1 mice (P<0.05). Moreover, CGA notably suppressed autophagosome production and enhanced autophagy flux in SH-SY5Y cells induced by Aβ_25-35 (P<0.05). Further analysis showed that CGA markedly promoted lysosomal activity, and this was accompanied by upregulated cathepsin D protein expression, which was induced by the mTOR/TFEB signaling pathway in APP/PS1 mice and Aβ_25-35-exposed SH-SY5Y cells (P<0.05).

Conclusion

CGA treatment restored autophagic flux in the brain and alleviated cognitive impairments in APP/PS1 mice via enhanced activation of the mTOR/TFEB signaling pathway.

β-Amyloid Peptide: the Cell Compartment Multi-faceted Interaction in Alzheimer's Disease

Alzheimer's disease (AD) is the most widespread form of dementia, characterized by memory loss and reduction of cognitive functions that strongly interfere with normal daily life. Numerous evidences show that aggregates of the amyloid beta peptide, formed by 39 to 42 amino acid residues (Aβ39-43), from soluble small oligomers to large fibrils are characteristic markers of this pathology. However, AD is a complex disease and its neurodegenerative molecular mechanism is not yet fully understood. Growing evidence suggests a link between Aβ polymorphic nature, oligomers and fibrils, and specific mechanisms of neurodegeneration. The Aβ variable nature and its multiplicity of interactions with different proteins and organelles reflect the complexity of this pathology. In this review, we analyze the effects of the interaction between Aβ peptide and different cellular compartments in relation to the different kinds and sizes of amyloid aggregates. In particular, Aβ interaction with different cell structures such as the plasma membrane, mitochondria, lysosomes, nucleus, and endoplasmic reticulum is discussed. Further, we analyze the Aβ peptide ability to modify the structure and function of the target organelle, inducing alteration of its physiological role thus contributing to the pathological event. Dysfunction of cellular components terminating with the activation of the cellular death mechanism and subsequent neurodegeneration is also taken into consideration.

Natural Compounds as Beneficial Antioxidant Agents in Neurodegenerative Disorders: A Focus on Alzheimer's Disease

The positive role of nutrition in chronic neurodegenerative diseases (NDs) suggests that dietary interventions represent helpful tools for preventing NDs. In particular, diets enriched with natural compounds have become an increasingly attractive, non-invasive, and inexpensive option to support a healthy brain and to potentially treat NDs. Bioactive compounds found in vegetables or microalgae possess special properties able to counteract oxidative stress, which is involved as a triggering factor in neurodegeneration. Here, we briefly review the relevant experimental data on curcuminoids, silymarin, chlorogenic acid, and compounds derived from the microalga Aphanizomenon flos aquae (AFA) which have been demonstrated to possess encouraging beneficial effects on neurodegeneration, in particular on Alzheimer's disease models.

Nucleoside 2',3'-Cyclic Monophosphates in Aphanizomenon flos-aquae Detected through Nuclear Magnetic Resonance and Mass Spectrometry

Aphanizomenon flos-aquae (AFA) cyanobacteria from Klamath Lake (Oregon) are considered a "superfood" due to their broad nutritional profile that has proved to have health-enhancing properties. The AFA metabolome is quite complex. Here, we present a study that, combining multinuclear ¹H, ³¹P, and ¹³C Nuclear Magnetic Resonance (NMR) spectroscopy and high-resolution mass spectrometry, led to the detection of uncommon phosphorylated metabolites in AFA. We focused our attention on ³¹P NMR signals at 20 ppm, a chemical shift that usually points to the presence of phosphonates. The molecules contributing to 20 ppm ³¹P NMR signals revealed, instead, to be nucleoside 2',3'-cyclic monophosphates. These metabolites were fully characterized by multinuclear ¹H, ³¹P, and ¹³C NMR spectroscopy and high-resolution mass spectrometry.

Heat-Resistant Aphanizomenon flos-aquae (AFA) Extract (Klamin®) as a Functional Ingredient in Food Strategy for Prevention of Oxidative Stress

Microalgae are generally considered an excellent source of vitamins, minerals, and bioactive molecules that make them suitable to be introduced in cosmetics, pharmaceuticals, and food industries. Aphanizomenon flos-aquae (AFA), an edible microalga, contains numerous biomolecules potentially able to prevent some pathologies including age-related disorders. With the aim to include an AFA extract (Klamin®) as a functional ingredient in baked products, we investigated if its bioactive molecules are destroyed or inactivated after standard cooking temperature. The AFA extract was exposed to heat stress (AFA-HS), and no significant decrease in pigment, polyphenol, and carotenoid content was detected by spectroscopic analysis. Thermal stability of AFA-HS extract was demonstrated by thermogravimetric analysis (TGA), and no change in the morphology of the granules of the powder was noticed by SEM microscopic observation. By Folin-Ciocalteu, ORAC, and ABTS assays, no change in the antioxidant activity and polyphenol contents was found after high-temperature exposition. When added in cell culture, solubilized AFA-HS lost neither its scavenging ability against ROS generation nor its protective role against Abeta, the main peptide involved in Alzheimer's disease. Prebiotic and antioxidant activities of AFA extract that are not lost after thermal stress were verified on E. coli bacteria. Finally, AFA-HS cookies, containing the extract as one of their ingredients, showed increased polyphenols. Here, we evaluate the possibility to use the AFA extract to produce functional food and prevent metabolic and age-related diseases.

Larrea tridentata Extract Mitigates Oxidative Stress-Induced Cytotoxicity in Human Neuroblastoma SH-SY5Y Cells

Creosote bush (Larrea tridentata; LT) leaves extracts were tested for their potential efficacy to mitigate cellular oxidative stress on human SH-SY5Y cells. Here, the differential nuclear staining assay, a bioimager system, and flow cytometric protocols, concurrently with several specific chemicals, were used to measure the percentage of cell viability and several facets implicated in the cytoprotective mechanism of LT extracts. Initially, three LT extracts, prepared with different solvents, ethanol, ethanol:water (e/w), and water, were tested for their capacity to rescue the viability of cells undergoing aggressive H₂O₂-induced oxidative stress. Results indicate that the LT extract prepared with a mixture of ethanol:water (LT-e/w; 60:40% v/v) displayed the most effective cytoprotection rescue activity. Interestingly, by investigating the LT-e/w mechanism of action, it was found that LT-e/w extract decreases the levels of H₂O₂-provoked reactive oxidative species (ROS) accumulation, mitochondrial depolarization, phosphatidylserine externalization, caspase-3/7 activation, and poly (ADP-ribose) polymerase (PARP) cleavage significantly, which are hallmarks of apoptosis. Thus, out of the three LT extracts tested, our findings highlight that the LT-e/w extract was the most effective protective reagent on SH-SY5Y cells undergoing oxidative stress in vitro, functioning as a natural anti-apoptotic extract. These findings warrant further LT-e/w extract examination in a holistic context.

Anthocyanins and Their Metabolites as Therapeutic Agents for Neurodegenerative Disease

Neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease, and amyotrophic lateral sclerosis (ALS), are characterized by the death of neurons within specific regions of the brain or spinal cord. While the etiology of many neurodegenerative diseases remains elusive, several factors are thought to contribute to the neurodegenerative process, such as oxidative and nitrosative stress, excitotoxicity, endoplasmic reticulum stress, protein aggregation, and neuroinflammation. These processes culminate in the death of vulnerable neuronal populations, which manifests symptomatically as cognitive and/or motor impairments. Until recently, most treatments for these disorders have targeted single aspects of disease pathology; however, this strategy has proved largely ineffective, and focus has now turned towards therapeutics which target multiple aspects underlying neurodegeneration. Anthocyanins are unique flavonoid compounds that have been shown to modulate several of the factors contributing to neuronal death, and interest in their use as therapeutics for neurodegeneration has grown in recent years. Additionally, due to observations that the bioavailability of anthocyanins is low relative to that of their metabolites, it has been proposed that anthocyanin metabolites may play a significant part in mediating the beneficial effects of an anthocyanin-rich diet. Thus, in this review, we will explore the evidence evaluating the neuroprotective and therapeutic potential of anthocyanins and their common metabolites for treating neurodegenerative diseases.

In vitro antioxidant, anti-glycation and immunomodulation activities of fermented blue-green algae Aphanizomenon flos-aquae

To clarify the antioxidant, anti-glycation and immunomodulatory capacities of fermented blue-green algae Aphanizomenon flos-aquae (AFA), hot aqueous extract suspensions made from 10% AFA were fermented by Lactobacillus plantarum AN7 and Lactococcus lactis subsp. lactis Kushiro-L2 strains isolated from a coastal region of Japan. The DPPH and O₂^- radical scavenging capacities and Fe-reducing power were increased in the fermented AFA. The increased DPPH radical scavenging capacity of the fermented AFA was fractionated to mainly < 3 kDa and 30-100 kDa. The increased O₂^- radical scavenging capacities were fractionated to mainly < 3 kDa. Anti-glycation activity in BSA-fructose model rather than BSA-methylglyoxal model was increased by the fermentation. The increased anti-glycation activity was fractionated to mainly 30-100 kDa. The NO concentration in the murine macrophage RAW264.7 culture media was high with the fermented AFA. The increased immunomodulation capacity was also fractionated to mainly 30-100 kDa. These results suggest that the fermented AFA is a more useful material for health foods and supplements.

Enhanced In Situ Availability of Aphanizomenon Flos-Aquae Constituents Entrapped in Buccal Films for the Treatment of Oxidative Stress-Related Oral Diseases: Biomechanical Characterization and In Vitro/Ex Vivo Evaluation

In recent years, the key role of oxidative stress in pathogenesis of oral diseases has been emphasized and the use of antioxidant agents has been encouraged. Aphanizomenon flos-aquae (AFA) is a unicellular blue-green alga with antioxidant and anti-inflammatory properties. The aim of this study was the formulation and characterization of mucoadhesive thin layer films loaded with AFA, finalized to the treatment of oxidative stress (OS)-related oral diseases. First, to enhance the bioavailability of AFA constituents, the raw food grade material was appropriately treated by a high frequency homogenization able to disrupt cell walls. Thus, Eudragit^® E100-based buccal films were produced by the solvent casting method, containing 7% and 18% of AFA. The films, characterized by uniformity in thickness, weight, and drug content, showed low swelling degree, good muco-adhesiveness and controlled drug release. The mechanical tests showed elastic moduli of films of almost 5 MPa that is well-suitable for human buccal applications without discomfort, besides biaxial tests highlighted a marked material isotropy. Permeation studies through porcine mucosae demonstrated the ability of films to promote AFA penetration in the tissues, and when sublingually administered, they produced a drug flux up to six-fold higher than an AFA solution. The new formulations represent an interesting alternative for the development of cosmetics and nutraceuticals with a functional appeal containing plant extracts.