Neuroprotective effect of Spirulina fusiform and amantadine in the 6-OHDA induced Parkinsonism in rats

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.

A Review on Natural Antioxidants for Their Role in the Treatment of Parkinson's Disease

The neurodegenerative condition known as Parkinson's disease (PD) is brought on by the depletion of dopaminergic neurons in the basal ganglia, which is the brain region that controls body movement. PD occurs due to many factors, from which one of the acknowledged effects of oxidative stress is pathogenic pathways that play a role in the development of Parkinson's disease. Antioxidants, including flavonoids, vitamins E and C, and polyphenolic substances, help to reduce the oxidative stress brought on by free radicals. Consequently, this lowers the risk of neurodegenerative disorders in the long term. Although there is currently no cure for neurodegenerative illnesses, these conditions can be controlled. The treatment of this disease lessens its symptoms, which helps to preserve the patient's quality of life. Therefore, the use of naturally occurring antioxidants, such as polyphenols, which may be obtained through food or nutritional supplements and have a variety of positive effects, has emerged as an appealing alternative management strategy. This article will examine the extent of knowledge about antioxidants in the treatment of neurodegenerative illnesses, as well as future directions for research. Additionally, an evaluation of the value of antioxidants as neuroprotective agents will be provided.

Exploring the Therapeutic Potential of Berberine and Tocopherol in Managing Diabetic Neuropathy: A Comprehensive Approach towards Alleviating Chronic Neuropathic Pain

Diabetic neuropathy (DN) causes sensory dysfunction, such as numbness, tingling, or burning sensations. Traditional medication may not ease pain and discomfort, but natural remedies such as Berberine (BR) and vitamin E or Tocopherol (TOC) have therapeutic potential to reduce inflammation while improving nerve function. Novel substances offer a more potent alternative method for managing severe chronic neuropathic pain that does not react to standard drug therapy by targeting various pathways that regulate it. Rats with diabetic control received oral doses of BR + TOC that showed significant changes in serum insulin levels compared to DN controls after 90 days, suggesting a decrease in sensitivity to painful stimuli partly by modulating the oxidative stress of the inflammatory pathway such as TNF-α suppression or stimulation of TNF-α depending on the amount of dose consumed by them. NF-kB also played its role here. Administering doses of BR and TOC reduced heightened levels of NF-kB and AGEs, effectively counteracting inflammation-targeted key factors in diabetes, promising possibilities for the benefits of these molecules revealed through in vivo investigation. In summary, treating neuropathy pain with a more comprehensive and organic approach can involve harnessing the powerful capabilities of BR and TOC. These compounds have been found to not only considerably decrease inflammation but also provide effective nerve protection while enhancing overall nerve function. With their multifunctional impacts on various neuropathic pain pathways in the body, these naturally occurring substances offer an exciting possibility for those who encounter high levels of neuropathic distress that do not respond well to conventional medication-centred therapies.

Antiglycoxidative properties of amantadine – a systematic review and comprehensive in vitro study

An important drug used in the treatment of Parkinson’s disease is amantadine. We are the first to perform a comprehensive study based on various glycation and oxidation factors, determining the impact of amantadine on protein glycoxidation. Sugars (glucose, fructose, galactose) and aldehydes (glyoxal, methylglyoxal) were used as glycation agents, and chloramine T was used as an oxidant. Glycoxidation biomarkers in albumin treated with amantadine were generally not different from the control group (glycation/oxidation factors), indicating that the drug did not affect oxidation and glycation processes. Molecular docking analysis did not reveal strong binding sites of amantadine on the bovine serum albumin structure. Although amantadine poorly scavenged hydroxyl radical and hydrogen peroxide, it had significantly lower antioxidant and antiglycation effect than all protein oxidation and glycation inhibitors. In some cases, amantadine even demonstrated glycoxidant, proglycation, and prooxidant properties. In summary, amantadine exhibited weak antioxidant properties and a lack of antiglycation activity.

The Protein-Rich Fraction from Spirulina platensis Exerts Neuroprotection in Hemiparkinsonian Rats by Decreasing Brain Inflammatory-Related Enzymes and Glial Fibrillary Acidic Protein Expressions

Spirulina platensis is a cyanobacterium with high protein content and presenting neuroprotective effects. Now, we studied a protein-enriched fraction (SPF), on behavior, neurochemical and immunohistochemical (IHC) assays in hemiparkinsonian rats, distributed into the groups: SO (sham-operated), 6-hydroxydopamine (6-OHDA), and 6-OHDA (treated with SPF, 5 and 10 mg/kg, p.o., 15 days). Afterward, animals were subjected to behavioral tests and euthanized, and brain areas used for neurochemical and IHC assays. SPF partly reversed the changes in the apomorphine-induced rotations, open field and forced swim tests, and also the decrease in striatal dopamine and 3,4-dihydroxyphenylacetic acid contents seen in hemiparkinsonian rats. Furthermore, SPF reduced brain oxidative stress and increased striatal expressions of tyrosine hydroxylase and dopamine transporter and significantly reduced hippocampal inducible nitric oxide synthase, cyclooxygenase-2 and glial fibrillary acidic protein expressions. The data suggest that the protein fraction from S. platensis, through its brain anti-inflammatory and antioxidative actions, exerts neuroprotective effects that could benefit patients affected by neurodegenerative diseases, like Parkinson's disease.

Spirulina platensis (Arthrospira platensis) attenuates Cyclophosphamide-induced reproductive toxicity in male Wistar rats: Evidence for sperm apoptosis and p53/Bcl-2 expression

Cyclophosphamide is an antitumor agent that causes disorders in fertility. This study aimed to evaluate the protective effects of Spirulina platensis against Cyclophosphamide-induced testicular toxicity. 42 male Wistar rats were randomly divided into six groups. Experimental groups included three groups. The first experimental group received Cyclophosphamide at a dose of 5 mg/kg body weight (BW) orally. The second and third experimental groups received 5 mg/kg BW Cyclophosphamide and 500 and 1,000 mg/kg BW S. platensis orally, respectively. The control groups included a control group, and two S. platensis control groups. Following 28 days, two flow cytometry techniques were used to determine sperm apoptosis and testicular protein expression of tumor protein (p53) and B-cell lymphoma 2 (Bcl-2). p53 is a tumor suppressor protein that causes the cell to enter the apoptosis cycle after DNA damage and Bcl-2 is an anti-apoptotic protein that acts through the mitochondrial pathway of apoptosis. FITC-Annexin V assay was used for sperm apoptosis evaluation. For protein expression assay, primary and secondary antibodies staining were performed. The Cyclophosphamide group showed a significant increase in sperm apoptosis compared to the control group. Cyclophosphamide significantly increased p53 and decreased Bcl-2 expression compared to the control group. S. platensis co-treated groups exhibited a significant decrease in sperm apoptosis compared to the Cyclophosphamide group. Moreover, S. platensis co-treated groups displayed a significant decreasing in p53 and increasing in Bcl-2 expression compared to the Cyclophosphamide group. The results of this study indicated that S. platensis protected rats against Cyclophosphamide-induced reproductive toxicity. PRACTICAL APPLICATIONS: Cyclophosphamide is the chemotherapy agent used to treat different cancers. Cyclophosphamide has side effects on the male reproductive system. Spirulina plantesis has a protective effect because of its antioxidant and anti-apoptotic properties. Co-administration of Spirulina plantesis with Cyclophosphamide reduces sperm apoptosis also decreases P53 protein expression and increases Bcl-2 protein expression. This study validated the anti-apoptotic potential of Spirulina plantesis against Cyclophosphamide-induced male reproductive toxicity.

Amantadine prevented hypersensitivity and decreased oxidative stress by NMDA receptor antagonism after spinal cord injury in rats

BACKGROUND

Neuropathic pain (NP) after spinal cord injury (SCI) is a disabling condition, without an effective treatment. Hyperexcitability of N-methyl-D-aspartate (NMDA) receptors and oxidative stress have been reported to be associated with pain development. Amantadine, an NMDA receptor antagonist, has been proposed as a potential therapy for NP. However, its use has not been tested for NP after SCI.

METHODS

To produce SCI, 120 female Wistar rats were used, a contusion injury to the T10 and T12 thoracic vertebrae was performed from heights of 6.25 mm and 12.5 mm. Nociceptive behaviour, was evaluated with the use of von Frey filaments for 31 days. The final products of lipid peroxidation (LP) and concentration of reduced glutathione (GSH) in the injured tissue were quantified by fluorescence spectrophotometry. The antinociceptive effect of the acute (15 days after the injury) and chronic (once daily for three days immediately after the injury) with amantadine (6.25-50 mg/Kg. I.p.) was determined. Finally, the LP and GSH were quantified in the injured tissue.

RESULTS

Acute treatment with amantadine reduced nociceptive behaviour. Concomitantly, LP was decreased by Amantadine treatment while GSH increased in the injured tissue. Similar effects were observed with chronic treatment with amantadine.

CONCLUSIONS

Data from this study suggested that the antinociceptive effects of amantadine treatment are modulated through oxidative stress and excitotoxicity reduction associated with N-methyl-D-aspartate receptors activation.

SIGNIFICANCE

This study suggests that acute treatment with amantadine decreases hypersensitivity threshold and frequency of hypersensitivity response in a dose-dependent manner, in rats with SCI, by decreasing oxidative stress. Since amantadine is an easily accessible drug and has fewer adverse effects than current treatments for hypersensitivity threshold and frequency of hypersensitivity response, amantadine could represent a safe and effective therapy for the treatment of neuropathic pain. However, further research is required to provide evidence of the effectiveness and feasibility.

Improved spinal cord gray matter morphology induced by Spirulina platensis following spinal cord injury in rat models

Despite intense preclinical research focusing on developing potential strategies of mitigating spinal cord injury (SCI), SCI still results in permanent, debilitating symptoms for which there are currently no effective pharmacological interventions to improve the recovery of the fine ultrastructure of the spinal cord. Spirulina platensis is thought to have potential neuroprotective effects. We have previously demonstrated its protective potential on the lesioned corticospinal tracts and behavioral recovery. In this study, spirulina, known for its neuroprotective properties was used to further explore its protective effects on spinal cord gray matter ultrastructural. Twenty-four Sprague-Dawley rats were used and divided into sham group (laminectomy without SCI), control group (SCI without S. platensis), and S. platensis group (SCI + 180 mg/kg S. platensis). All animals were anesthetized via intramuscular injection. A partial crush injury was induced at the level of T12. The rats were humanely sacrificed for 28 days postinjury for ultrastructural study. There were significant mean differences with respect to pairwise comparisons between the ultrastructural grading score of neuronal perikarya of control and the S. platensis following injury at day 28, which correlates with the functional locomotor recovery at this timepoint in our previous study. The group supplemented with spirulina, thus, revealed a better improvement in the fine ultrastructure of the spinal cord gray matter when compared to the control group thereby suggesting neuroprotective potentials of spirulina in mitigating the effects of spinal cord injury and inducing functional recovery.

Therapeutic Effects of Spirulina platensis Against Adolescent Stress-Induced Oxidative Stress, Brain-Derived Neurotrophic Factor Alterations and Morphological Remodeling in the Amygdala of Adult Female Rats

Objective

The amygdala structural and functional abnormalities have been implicated in numerous neuropsychiatric and neurodevelopmental disorders. Given the important role of the amygdala in stress responses and the susceptibility of the females to adolescent stress, the present study investigated the beneficial effects of Spirulina platensis microalgae (SP) as a neuroprotective supplement against adolescent stress-induced oxidative stress, brain-derived neurotrophic factor (BDNF) alterations, molecular and morphological remodeling in the basolateral amygdala (BLA) of adult female rats.

Methods

During the adolescent period (PNDs 30–40) rats were subjected to restraint stress (2 h/day for 10 days). Then, the animals were subjected to 15 days treatment (PNDs 41–55) with SP (200 mg/kg/day) followed by biochemical (BDNF and stress oxidative markers), molecular (BDNF and its receptor tropomyosin receptor kinase B [TrkB] mRNA expression), and morphological (dendritic length and spines) assessments in the BLA.

Results

The study revealed that adolescent stress decreased BDNF levels and reduced apical dendritic length and branch points of pyramidal neurons in the BLA. In addition, chronic stress significantly increased oxidative stress parameters and decreased BDNF and TrkB mRNA expression in the BLA. Treatment with SP alleviated both biochemical, molecular, and neuroanatomical deficits that induced by adolescent stress.

Conclusion

Our findings provide important evidence that SP as a non-pharmacological intervention during adolescent period can protect against chronic stress-induced neuroanatomical biochemical, and molecular deficits in adulthood, and thus, reduce stress-related disorders.

Protective Effects of Spirulina platensis, Voluntary Exercise and Environmental Interventions Against Adolescent Stress-Induced Anxiety and Depressive-Like Symptoms, Oxidative Stress and Alterations of BDNF and 5HT-3 Receptors of the Prefrontal Cortex in Female Rats

BACKGROUND AND PURPOSE

Ample evidence indicates that chronic adolescence stress is associated with an increased risk of developing neuropsychiatric disorders in adulthood. Given the importance of the effective therapeutic ways to overcome adolescent stress-related deficits, the present study investigated the effects of Spirulina platensis (SP), environmental enrichment (EE), and voluntary exercise (EX) and their combination on anxiety or depression-like behaviors, oxidative stress, and alterations of BDNF and 5HT-3 receptors in the prefrontal cortex (PFC) induced by adolescent stress in adult female rats.

METHODS

During the adolescent period (PNDs30-40), rats were subjected to restraint stress. Then, the animals were subjected to SP treatment (200 mg/kg/day), EX, EE, and the combined treatments (SP+EX, and SP+EE) for 15 days between PNDs41-55. Subsequently, anxiety or depression-like behaviors, BDNF levels, oxidative stress markers and mRNA expression of BDNF and 5HT₃ in the PFC were assessed.

RESULTS

Stressed rats demonstrated enhanced anxiety levels and depression-like behaviors in adulthood. Regarding the oxidative stress markers, stressed rats exhibited significantly higher levels of malondialdehyde, a lipid peroxidation product, higher activities of antioxidant enzymes (glutathione peroxidase and superoxide dismutase) and significantly lower total antioxidant reactivity capacity in the PFC. Additionally, adolescent stress significantly increased 5HT3 receptor mRNA expression and decreased BDNF content and its mRNA expression in the PFC. Treatments with SP, EX, EE, and the combined interventions alleviated these deficits.

CONCLUSION

Our findings indicate that appropriate interventions during the adolescent period can protect against adolescent stress-induced behavioral, and biochemical defects and oxidative stress damage in adulthood.

Neuroprotective potential of Spirulina platensis on lesioned spinal cord corticospinal tract under experimental conditions in rat models

Spinal cord injury (SCI) results from penetrating or compressive traumatic injury to the spine in humans or by the surgical compression of the spinal cord in experimental animals. In this study, the neuroprotective potential of Spirulina platensis was investigated on ultrastructural and functional recovery of the spinal cord following surgical-induced injury. Twenty-four Sprague-Dawley rats were divided into three groups; sham group, control (trauma) group, and experimental (S. platensis) group (180 mg/kg) of eight rats each. For each group, the rats were then subdivided into two groups to allow measurement at two different timepoints (day 14 and 28) for the microscopic analysis. Rats in the control and experimental S. platensis groups were subjected to partial crush injury at the level of T12 with Inox number 2 modified forceps by compressing on the spinal cord for 30 s. Pairwise comparisons of ultrastructural grading mean scores difference between the control and experimental S. platensis groups reveals that there were significant differences on the axonal ultrastructure, myelin sheath and BBB Score on Day 28; these correlate with the functional locomotor recovery at this timepoint. The results suggest that supplementation with S. platensis induces functional recovery and effective preservation of the spinal cord ultrastructure after SCI. These findings will open new potential avenue for further research into the mechanism of S. platensis-mediated spinal cord repair.

Beneficial effects of Spirulina platensis, voluntary exercise and environmental enrichment against adolescent stress induced deficits in cognitive functions, hippocampal BDNF and morphological remolding in adult female rats

Chronic exposure to stress during adolescent period has been demonstrated to impair cognitive functions and the dendritic morphology of pyramidal neurons in the rat hippocampal CA3 area. The present study investigated the combined protective effects of Spirulina platensis (SP), a supplement made from blue-green algae with neuroprotective properties, voluntary exercise (EX) and environmental enrichment (EE) against cognitive deficits, alternations in hippocampal BDNF levels, and abnormal neuronal remodeling in adult female rats (PND 60) induced by exposure to chronic restraint stress during adolescent period (PND 30-40). Rats were exposed to restraint stress (2 h/day for 10 days, PND 30-40). Then, the animals were subjected to treatment with SP (200 mg/kg/day), EX, EE and the combined treatments (SP + EX, and SP + EE) between PND 41 and 55 of age. Following the interventions, spatial learning and memory, passive avoidance performance, hippocampal dendritic morphology and BDNF levels were assessed. Results showed that plasma corticosterone levels increased at PND 40 and remained elevated at PND 55 and 70 in the stressed rats. Stressed rats showed deficits in spatial learning and memory and passive avoidance performance, decreased BDNF levels in the hippocampus, and reduced apical dendritic length and branch points of the CA3 pyramidal neurons. These deficits were alleviated by the SP, EX and EE, and the combined treatments, which accompanied with a decline in serum corticosterone in stressed animals. Some treatments even enhanced cognitive functions, and BDNF levels and neuroanatomical remodeling in the hippocampus of non-stressed animals. Our findings provide important evidences that physical activity, exposure to EE, and the SP treatment during adolescent period can protect against adolescent stress induced behavioral, biochemical and neuroanatomical impairments in adulthood.

Neuroprotective Activities of Spirulina platensis in the 6-OHDA Model of Parkinson's Disease Are Related to Its Anti-Inflammatory Effects

Spirulina platensis (SPI) is a cyanobacterium, presenting anti-inflammatory and antioxidant actions. Considering the importance of inflammation and oxidative stress in Parkinson's disease (PD), SPI neuroprotective effects were evaluated in a model of PD. Male Wistar rats were divided into: sham-operated (SO), untreated 6-OHDA and 6-OHDA treated with SPI (25 and 50 mg/kg, p.o.). The 6-OHDA was injected into the right striata and SPI treatments started 24 h later for 2 weeks. The SO and untreated 6-OHDA-lesioned groups were administered with distilled water, for the same period. Afterwards, the animals were subjected to the apomorphine-induced rotational test and euthanized for striatal measurements of DA and DOPAC, nitrite and TBARS and immunohistochemistry assays for TH, DAT, iNOS and COX-2. SPI reduced the apomorphine-induced rotational behavior, DA and DOPAC depletions and nitrite and TBARS increases, at its high dose. Furthermore, TH and DAT immunoreactivities in the lesioned striatum of the untreated 6-OHDA-lesioned group were attenuated by SPI. Similarly, immunoreactivities for iNOS and COX-2 were also decreased after SPI treatments. In conclusion, we showed that behavioral and neurochemical alterations in hemiparkinsonian rats were partly reversed by SPI, characterizing the neuroprotective potential of Spirulina and stimulating translational studies focusing on its use as an alternative treatment for PD.

The Role of Group II Metabotropic Glutamate Receptors in the Striatum in Electroacupuncture Treatment of Parkinsonian Rats

AIMS

Glutamatergic transmission may play a critical role in the pathogenesis of Parkinson's disease (PD). Electroacupuncture (EA) has been demonstrated to effectively alleviate PD symptoms. In this study, a potential glutamate-dependent mechanism underlying the therapeutic action of EA was investigated.

METHODS

The effects of EA stimulation on motor behaviors, dopamine contents, glutamate release, and group II metabotropic glutamate receptor (mGluR2/3) expression in unilateral 6-hydroxydopamine (6-OHDA)-lesioned rats were examined.

RESULTS

Unilateral 6-OHDA lesions of the nigrostriatal system caused a marked increase in glutamate content in the ipsilateral cortex and striatum. mGluR2/3 protein expression and mGluR3 mRNA expression were reduced in the striatum. Noticeably, prolonged EA stimulation at 100 Hz significantly reversed these changes in the striatal glutamate system. Behaviorally, EA improved the motor deficits induced by 6-OHDA lesions. Intrastriatal infusion of an mGluR2/3 antagonist APICA blocked the improving effect of EA.

CONCLUSIONS

These data collectively demonstrate that the group II mGluR-mediated glutamatergic transmission in the striatum is sensitive to dopamine depletion and may serve as a substrate of EA for mediating the therapeutic effect of EA in a rat model of PD.