Protective effect of naringin against ischemic reperfusion cerebral injury: Possible neurobehavioral, biochemical and cellular alterations in rat brain

NaturalEssential Oils: A Promising Therapy Way for Treating Ischemic Stroke

Stroke is an acute cerebrovascular disease with high morbidity, mortality, and disability, making it the second leading cause of death worldwide. Ischemic stroke (IS) accounts for the majority of strokes, and its pathogenesis is complex, often involving complications and sequelae. Currently, conventional clinical approaches are ineffective, with few drugs available for intravenous thrombolysis and mechanical thrombolysis limited by a short time window. With the poor efficacy of monotherapy, the search for new complementary or alternative therapies has become the focus of researchers. In traditional medicine, Chinese aromatherapy has a long history of using aromatic medicines to treat IS. Natural essential oils (EOs), as the main pharmacological substances in aromatic drugs, are composed of different ratios of active metabolites with multi-targets and multi-components, which makes EOs have a wide range of pharmacological effects. Modern studies have also shown that EOs extracts and isolated monomers are beneficial for pathologically complex CIS. Therefore, this paper summarizes the EOs and monomers obtained from EOs that can prevent and treat IS in the last 20 years, and finds that EOs exert their anti-CIS effects mainly through anti-oxidative stress, anti-inflammation, anti-apoptosis, and inhibition of excitotoxicity. The amelioration of IS complications by natural EOs and their active monomer components for the treatment of IS are further discussed.

Efficacy of ozonated autohemotherapy for improvement of myocardial injury following traumatic brain injury

BACKGROUND

Traumatic brain injury is a kind of injury caused by external violence on the head. Its danger is not limited to life rescue in the early stage of the disease. Moreover, the subsequent inflammatory reaction and the change in its oxidative stress level will cause secondary myocardial injury. The purpose of this study is to explore the myocardial protective effect of ozone autohemotherapy (OA) in the progression of acute traumatic brain injury (TBI).

METHODS

Forty patients with acute TBI were recruited and divided into The treatment group (Group OA, n = 18) and the Control group (Group C, n = 19). Patients in Group OA received OA before surgery and on the 1st and 2nd postoperative days, while patients in Group C underwent autologous blood transfusion. Venous blood was collected from all patients before (T0) and after 7 days (T1) days of surgery for measurement of cardiac troponin T (cTnT) and amino-terminal pro-B-type natriuretic peptide (NT-proBNP). At T0 and T1, transthoracic cardiac ultrasound was performed to measure left ventricular ejection fraction (LVEF), tricuspid annular plane systolic excursion (TAPSE), and venous blood was sampled to determine the contents of superoxide dismutase (SOD) and malondialdehyde (MDA). NIH Stroke Scale (NIHSS) and Glasgow Coma Scale (GCS) scores were calculated, and other clinical indexes were recorded.

RESULTS

(1) The levels of cTnT at T1 were significantly higher as compared with that at T0 in both groups (p < 0.01). Compared with Group C, a remarkable decline in the content of NT-proBNP was found in Group OA at T1 (p = 0.021). (2) The LVEF (p = 0.002) and serum SOD (p = 0.015) at T1 were significantly increased in Group OA as compared with those in Group C. (3) The length of Intensive Care Unit and hospitalization time for patients in Group OA was distinctly shorter than that for patients in Group C (p = 0.021, p = 0.015, respectively).

CONCLUSION

Perioperative OA treatment can alleviate the secondary myocardial injury during the disease course of TBI, which might be associated with its myocardial protective effect against oxidative stress.

TRIAL REGISTRATION

This study was approved by the Ethical Committee of Changzhou NO.2 People's Hospital. The protocol was registered prospectively with the Chinese Clinical Trial Registry (ChiCTR2000029612) on February 02, 2020.

Combined effect of naringin and adipose tissue-derived mesenchymal stem cell on cisplatin nephrotoxicity through Sirtuin1/Nrf-2/HO-1 signaling pathway: a promising nephroprotective candidate

Cisplatin nephrotoxicity is a well-known emergency clinical condition caused by oxidative stress and inflammation. Naringin (NAR) is considered an antioxidant agent with renoprotective effects capable of removing reactive oxygen species. Adipose tissue-derived mesenchymal stem cells (AD-MSCs) are reported to have anti-inflammatory and antioxidant properties. The present research examined the renoprotective effect of the combination of NAR and AD-MSCs as opposed to each one alone on cisplatin-induced nephrotoxicity through SIRT-1/Nrf-2/HO-1 pathway. This study included five groups (n = 8 each) of male Sprague-Dawley rats (200 - 220 g): sham, cisplatin: rats receiving cisplatin (6.5 mg/kg, i.p.) on the 4th day; NAR+cisplatin: rats pretreated with NAR (1 week, i.p.) + cisplatin on the 4th day; AD-MSCs: rats receiving AD-MSCs (1 × 106) by injection through the tail vein on the 5th day + cisplatin on the 4th day; and NAR+AD-MSCs+cisplatin. On the 8th day, the animals were anesthetized to obtain tissue and blood samples. Biochemical factors, inflammation, oxidative stress, and gene expression were explored. Cisplatin increased blood urea nitrogen, creatinine, inflammation, and oxidative stress. Moreover, mRNA expression of Sirtuin1, nuclear factor erythroid 2-related factor 2 (Nrf-2), and heme oxygenase-1 (HO-1) remarkably reduced. Furthermore, cisplatin led to a disturbance in kidney structure (glomerular atrophy, cell infiltrations, and tubular dysfunction) as confirmed by histology findings. However, NAR pretreatment, AD-MSC administration, or a combination of both significantly reversed these changes. Overall, when used together, NAR and AD-MSCs had stronger cisplatin-induced effects on kidney dysfunction by inhibiting inflammation, reducing oxidative stress, and increasing the Sirtuin1/Nrf-2/HO-1 pathway.

The neuroprotective effect of Chinese herbal medicine for cerebral ischemia reperfusion injury through regulating mitophagy

The incidence of ischemic stroke has been increasing annually with an unfavorable prognosis. Cerebral ischemia reperfusion injury can exacerbate nerve damage. Effective mitochondrial quality control including mitochondrial fission, fusion and autophagy, is crucial for maintaining cellular homeostasis. Several studies have revealed the critical role of mitophagy in Cerebral ischemia reperfusion injury. Cerebral ischemia and hypoxia induce mitophagy, and mitophagy exhibits positive and negative effects in cerebral ischemia reperfusion injury. Studies have shown that Chinese herbal medicine can alleviate Cerebral ischemia reperfusion injury and serve as a neuroprotective agent by inhibiting or promoting mitophagy-mediated pathways. This review focuses on the mitochondrial dynamics and mitophagy-related pathways, as well as the role of mitophagy in ischemia reperfusion injury. Additionally, it discusses the therapeutic potential and benefits of Chinese herbal monomers and decoctions in the treatment of ischemic stroke.

Effect of 2-Week Naringin Supplementation on Neurogenesis and BDNF Levels in Ischemia-Reperfusion Model of Rats

BACKGROUND

Ischemic stroke is the leading cause of mortality and disability worldwide with more than half of survivors living with serious neurological sequelae; thus, it has recently attracted a lot of attention in the field of medical study.

PURPOSE

The aim of this study was to determine the effect of naringin supplementation on neurogenesis and brain-derived neurotrophic factor (BDNF) levels in the brain in experimental brain ischemia-reperfusion.

STUDY DESIGN

The research was carried out on 40 male Wistar-type rats (10-12 weeks old) obtained from the Experimental Animals Research and Application Center of Selçuk University. Experimental groups were as follows: (1) Control group, (2) Sham group, (3) Brain ischemia-reperfusion group, (4) Brain ischemia-reperfusion + vehicle group (administered for 14 days), and (5) Brain ischemia-reperfusion + Naringin group (100 mg/kg/day administered for 14 days).

METHODS

In the ischemia-reperfusion groups, global ischemia was performed in the brain by ligation of the right and left carotid arteries for 30 min. Naringin was administered to experimental animals by intragastric route for 14 days following reperfusion. The training phase of the rotarod test was started 4 days before ischemia-reperfusion, and the test phase together with neurological scoring was performed the day before and 1, 7, and 14 days after the operation. At the end of the experiment, animals were sacrificed, and then hippocampus and frontal cortex tissues were taken from the brain. Double cortin marker (DCX), neuronal nuclear antigen marker (NeuN), and BDNF were evaluated in hippocampus and frontal cortex tissues by Real-Time qPCR analysis and immunohistochemistry methods.

RESULTS

While ischemia-reperfusion increased the neurological score values, DCX, NeuN, and BDNF levels decreased significantly after ischemia in the hippocampus and frontal cortex tissues. However, naringin supplementation restored the deterioration to a certain extent.

CONCLUSION

The results of the study show that 2 weeks of naringin supplementation may have protective effects on impaired neurogenesis and BDNF levels after brain ischemia and reperfusion in rats.

Naringin and Naringenin Polyphenols in Neurological Diseases: Understandings from a Therapeutic Viewpoint

The glycosides of two flavonoids, naringin and naringenin, are found in various citrus fruits, bergamots, tomatoes, and other fruits. These phytochemicals are associated with multiple biological functions, including neuroprotective, antioxidant, anticancer, antiviral, antibacterial, anti-inflammatory, antiadipogenic, and cardioprotective effects. The higher glutathione/oxidized glutathione ratio in 3-NP-induced rats is attributed to the ability of naringin to reduce hydroxyl radical, hydroperoxide, and nitrite. However, although progress has been made in treating these diseases, there are still global concerns about how to obtain a solution. Thus, natural compounds can provide a promising strategy for treating many neurological conditions. Possible therapeutics for neurodegenerative disorders include naringin and naringenin polyphenols. New experimental evidence shows that these polyphenols exert a wide range of pharmacological activity; particular attention was paid to neurodegenerative diseases such as Alzheimer's and Parkinson's diseases, as well as other neurological conditions such as anxiety, depression, schizophrenia, and chronic hyperglycemic peripheral neuropathy. Several preliminary investigations have shown promising evidence of neuroprotection. The main objective of this review was to reflect on developments in understanding the molecular mechanisms underlying the development of naringin and naringenin as potential neuroprotective medications. Furthermore, the configuration relationships between naringin and naringenin are discussed, as well as their plant sources and extraction methods.

Omarigliptin attenuates rotenone-induced Parkinson's disease in rats: Possible role of oxidative stress, endoplasmic reticulum stress and immune modulation

The current study aimed to explore the potential neuroprotective effect of omarigliptin (OG), an antidiabetic drug that crosses the blood-brain barrier (BBB), in a Parkinson's disease (PD) rotenone-based rat-model. Results showed that OG attenuated motor impairment, histological aberrations, α-synuclein accumulation, and rescued the dopaminergic neurons in rotenone-administered rats. Furthermore, OG halted rotenone-induced oxidative stress; as shown by reduced lipid peroxidation, decline in the oxidative stress sensor (nuclear factor erythroid 2-related factor 2) and its downstream heme oxygenase-1. In addition, OG abrogated neuroinflammation and apoptosis in rotenone-treated rats. Moreover, OG ameliorated endoplasmic reticulum (ER) stress in rotenone-administered rats; as evidenced by reduced levels of ER resident proteins such as glucose-regulated protein 78, C/EBP homologous protein and apoptotic caspase-12. In conclusion, this study implies repurposing of OG, as a novel neuroprotective agent due to its antioxidant properties, its effects on ER stress in addition to its anti-inflammatory and anti-apoptotic activities.

Naringin Mediates Adult Hippocampal Neurogenesis for Antidepression via Activating CREB Signaling

The brain-derived neurotrophic factor/tropomyosin receptor kinase B/cAMP response element-binding protein (BDNF/TrkB/CREB) signaling pathway is a critical therapeutic target for inducing adult hippocampal neurogenesis and antidepressant therapy. In this study, we tested the hypothesis that naringin, a natural medicinal compound, could promote adult hippocampal neurogenesis and improve depression-like behaviors via regulating the BDNF/TrkB/CREB signaling pathway. We first investigated the effects of naringin on promoting adult hippocampal neurogenesis in both normal and chronic corticosterone (CORT)-induced depressive mice. Under physiological condition, naringin treatment enhanced the proliferation of neural stem/progenitor cells (NSPCs) and accelerated neuronal differentiation. In CORT-induced depression mouse model, naringin treatment promoted neuronal differentiation and maturation of NSPCs for hippocampal neurogenesis. Forced swim test, tail suspension test, and open field test confirmed the antidepressant and anxiolytic effects of naringin. Co-treatment of temozolomide (TMZ), a neurogenic inhibitor, abolished these antidepressant and anxiolytic effects. Meanwhile, naringin treatment increased phosphorylation of cAMP response element binding protein (CREB) but had no effect on the expression of brain-derived neurotrophic factor and phosphorylation of TrkB in the hippocampus of CORT-induced depressive mice. Co-treatment of CREB inhibitor 666-15, rather than TrkB inhibitor Cyc-B, abolished the neurogenesis-promoting and antidepressant effects of naringin. Taken together, naringin has antidepressant and anxiolytic effects, and the underlying mechanisms could be attributed to enhance hippocampal neurogenesis via activating CREB signaling.

A prognostic study on the effect of post-traumatic stress disorder on cerebral ischaemia reperfusion-induced stroke

OBJECTIVES

Previous studies have been established that persons who experienced a stroke are soon likely to develop several anxiety disorders. In which one of the major anxiety disorders is Post-traumatic Stress Disorder (PTSD). Yet, the likelihood of PTSD in conjunction with cerebral stroke has not been well described. Hence, we evaluated the impact of PTSD on cerebral stroke in rodents subjected to single prolonged stress (SPS) and bilateral common carotid artery occlusion (BCCAo), respectively.

METHODS

The relation between PTSD and cerebral stroke is evaluated by performing behavioural, biochemical, histopathological, and brain lesion area measurement studies.

RESULTS

Interestingly, SPS + BCCAo induction increased behavioural abnormalities like cognitive impairment and anxiety-like behaviour compared to SPS and BCCAo groups alone. Motor impairment was also observed in SPS + BCCAo rats compared to SPS rats, whereas no change with BCCAo rats. Furthermore, increased brain tissue MDA, acetylcholinesterase, and decreased SOD, catalase, and GSH were observed in SPS + BCCAo subjected rats compared to SPS and BCCAo rats alone. Additionally, SPS + BCCAo induction considerably increased the plasma corticosterone levels and caused severe neurotransmitter alterations. The SPS + BCCAo exposure significantly increased the brain lesion area in comparison with BCCAo rats. Moreover, severe histopathological alterations were observed in the hippocampus (CA1) of SPS + BCCAo rats compared to SPS and BCCAo rats alone.

CONCLUSIONS

In conclusion, our study results suggested that SPS-induced PTSD may aggravate the BCCAo induced cerebral ischaemia-reperfusion injury.

Spontaneous, transient adenosine release is not enhanced in the CA1 region of hippocampus during severe ischemia models

Ischemic stroke causes damage in the brain, and a slow buildup of adenosine is neuroprotective during ischemic injury. Spontaneous, transient adenosine signaling, lasting only 3 s per event, has been discovered that increases in frequency in the caudate-putamen during early stages of mild ischemia-reperfusion injury. However, spontaneous adenosine changes have not been studied in the hippocampus during ischemia, an area highly susceptible to stroke. Here, we investigated changes of spontaneous, transient adenosine in the CA1 region of rat hippocampus during three different models of the varied intensity of ischemia. During the early stages of the milder bilateral common carotid artery occlusion (BCCAO) model, there were fewer spontaneous, transient adenosine, but no change in the concentration of individual events. In contrast, during the moderate 2 vertebral artery occlusion (2VAO) and severe 4 vessel occlusion (4VO) models, both the frequency of spontaneous, transient adenosine and the average event adenosine concentration decreased. Blood flow measurements validate that the ischemia models decreased blood flow, and corresponding pathological changes were observed by transmission electron microscopy (TEM). 4VO occlusion showed the most severe damage in histology and BCCAO showed the least. Overall, our data suggest that there is no enhanced spontaneous adenosine release in the hippocampus during moderate and severe ischemia, which could be due to depletion of the rapidly releasable adenosine pool. Thus, during ischemic stroke, there are fewer spontaneous adenosine events that could inhibit neurotransmission, which might lead to more damage and less neuroprotection in the hippocampus CA1 region. Read the Editorial Highlight for this article on page 800.

Elimination of Giardia duodenalis BIV in vivo using natural extracts in microbiome and dietary supplements

In this study, a combination therapy of several natural products was evaluated in vivo in the Giardia duodenalis infection model. G. duodenalis infected mice were treated as follows: distilled water (infected control C+), BIOintestil® (BIO; natural products of Cymbopogon martinii and Zingiber officinale), MicrobiomeX® (MBX; extract of Citrus sinensis and Citrus paradisi), MBX + BIO, Camellia sinensis tea (CPR; black tea). These natural compounds were administered in a dose of 100 mg/day and were compared to G. duodenalis-infected mice treated with albendazole (ALB; 50 mg/Kg/day) and metronidazole (MET; 500 mg/Kg/day), the conventional therapies used to this day. One group remained un-infected and untreated as our control group (C-). Treatment started 8 days after infection, and after 5 days of treatment (7 days for MET), all animals were followed for 15 days. We continuously checked for the presence of G. duodenalis by Faust method, in association with detection of the parasite by PCR from feces, as well for the presence of trophozoites in the intestinal mucosa after sacrifice. Animals treated with MBX, BIO and MBX + BIO presented an undetectable parasitic load until the 15th day of monitoring, while animals treated with CPR, MET and ALB continued to release cysts. Animals in the MBX, MBX + BIO, ALB groups consumed lower feed, MBX, CPR, MET had greater weight and MBX, MBX + BIO, BIO, CPR, C- consumed more water when compared to infected-group control. MBX and BIO alone or associated eliminated G. duodenalis without apparent adverse effects and animals of these groups showed better clinical performance in relation to those with high parasitic load. MET, ALB and CPR only decreased the number of cysts, indicating limitations and therapeutic failure.

Pressurized Extraction as an Opportunity to Recover Antioxidants from Orange Peels: Heat treatment and Nanoemulsion Design for Modulating Oxidative Stress

Orange peel by-products generated in the food industry are an important source of value-added compounds that can be potentially reused. In the current research, the effect of oven-drying (50–70 °C) and freeze-drying on the bioactive compounds and antioxidant potential from Navelina, Salustriana, and Sanguina peel waste was investigated using pressurized extraction (ASE). Sixty volatile components were identified by ASE-GC-MS. The levels of terpene derivatives (sesquitenenes, alcohols, aldehydes, hydrocarbons, and esters) remained practically unaffected among fresh and freeze-dried orange peels, whereas drying at 70 °C caused significative decreases in Navelina, Salustriana, and Sanguina peels. Hesperidin and narirutin were the main flavonoids quantified by HPLC-MS. Freeze-dried Sanguina peels showed the highest levels of total-polyphenols (113.3 mg GAE·g⁻¹), total flavonoids (39.0 mg QE·g⁻¹), outstanding values of hesperedin (187.6 µg·g⁻¹), phenol acids (16.54 mg·g⁻¹ DW), and the greatest antioxidant values (DPPH•, FRAP, and ABTS^•+ assays) in comparison with oven-dried samples and the other varieties. Nanotechnology approaches allowed the formulation of antioxidant-loaded nanoemulsions, stabilized with lecithin, starting from orange peel extracts. Those provided 70–80% of protection against oxidative UV-radiation, also decreasing the ROS levels into the Caco-2 cells. Overall, pressurized extracts from freeze-drying orange peel can be considered a good source of natural antioxidants that could be exploited in food applications for the development of new products of commercial interest.

Naringin and Trimetazidine Improve Baroreflex Sensitivity and Nucleus Tractus Solitarius Electrical Activity in Renal Ischemia-Reperfusion Injury

BACKGROUND

Nucleus tractus solitarius (NTS) is a brain area that plays a key role in kidney and cardiovascular regulation via baroreceptors impulses.

OBJECTIVES

The aim of this study was to evaluate the effect of naringin (NAR) and trimetazidine (TMZ) alone and their combination on NTS electrical activity and baroreceptor sensitivity (BRS) in renal ischemia- reperfusion (I/R) injury.

METHODS

Forty male Sprague-Dawley rats (200- 250 g) were allocated into 5 groups with 8 in each. 1) Sham; 2) I/R; 3) TMZ 5 mg/kg; 4) NAR 100 mg/kg; and 5) TMZ5+ NAR100. The left femoral vein was cannulated to infuse saline solution or drug and the BRS was evaluated. I/R was induced by occlusion of renal pedicles for 45 min, followed by 4 hours of reperfusion. The NTS local electroencephalogram (EEG) was recorded before, during ischemia and throughout the reperfusion. Phenylephrine was injected intravenously to evaluate BRS at the end of reperfusion time. The data were analyzed by two-way repeated measurement ANOVA followed by Tukey's post hoc test. A p-value <0.05 was considered significant.

RESULTS

NTS electrical waves did not change during ischemia time, while they significantly decreased during the entire reperfusion time. NTS electrical activity and BRS dramatically reduced in rats with I/R injury; however, administration of NAR, TMZ alone or their combination significantly improved these changes in rats with I/R injury.

CONCLUSIONS

The results showed that I/R injury leads to reduced BRS and NTS electrical activity and there may be an association between I/R and decreased BRS. In addition, NAR and TMZ are promising agents to treat I/R complications.

An Overview of Stroke: Mechanism, In vivo Experimental Models Thereof, and Neuroprotective Agents

BACKGROUND

Stroke is one of the causes of death and disability globally. Brain attack is because of the acute presentation of stroke, which highlights the requirement for decisive action to treat it.

OBJECTIVE

The mechanism and in-vivo experimental models of stroke with various neuroprotective agents are highlighted in this review.

METHOD

The damaging mechanisms may proceed by rapid, nonspecific cell lysis (necrosis) or by the active form of cell death (apoptosis or necroptosis), depending upon the duration and severity and of the ischemic insult.

RESULTS

Identification of injury mediators and pathways in a variety of experimental animal models of global cerebral ischemia has directed to explore the target-specific cytoprotective strategies, which are critical to clinical brain injury outcomes.

CONCLUSION

The injury mechanism, available encouraging medicaments thereof, and outcomes of natural and modern medicines for ischemia have been summarized. In spite of available therapeutic agents (thrombolytics, calcium channel blockers, NMDA receptor antagonists and antioxidants), there is a need for an ideal drug for strokes.

Naringin attenuates cerebral ischemia-reperfusion injury in rats by inhibiting endoplasmic reticulum stress

Objective

This investigation was carried out with an aim of exploring neuroprotection by naringin (Nar) in rats with cerebral ischemia-reperfusion (CI/R) injury and its mechanism.

Methods

Rats were grouped into ischemia-reperfusion (I/R), sham operation (Sham), nimodipine control (NIM), and different doses of Nar (Nar-L, Nar-M, Nar-H) groups. With Zea Longa score for assessment of neurological deficits, dry and wet method for measurement of brain tissue water content, and (2,3,5-triphenyltetrazolium chloride) TTC staining for determination of cerebral infarction volume, the related parameters were obtained and compared. Subsequently, ELISA was introduced to detect levels of proinflammatory cytokines (TNF-α, IL-8) and anti-inflammatory cytokine (IL-10) in the serum as well as superoxide dismutase (SOD) and malondialdehyde (MDA) activities in brain tissue. Western blot was applied to evaluate endoplasmic reticulum stress (ERS)-related proteins expression, including glucose-regulated protein 78 (GRP78), C/EBP homologous protein (CHOP), caspase-12, and activating transcription factor 6 (ATF-6).

Results

Nar significantly alleviated nerve injury and decreased brain tissue water content and brain infraction volume in CI/R injury rats in a concentration-dependent manner. Reduction of TNF-α, IL-8 as well as MDA content and elevation of IL-10 as well as SOD activity were confirmed to be caused by Nar treatment in a concentration-dependent manner. Meanwhile, ERS-related proteins also markedly decreased in the Nar groups.

Conclusion

Nar may achieve neuroprotection and alleviation of CI/R injury by anti-inflammation, anti-oxidation, and inhibiting ERS, and its efficacy is concentration-dependent.

The Mitochondrial mitoNEET Ligand NL-1 Is Protective in a Murine Model of Transient Cerebral Ischemic Stroke

PURPOSE

Therapeutic strategies to treat ischemic stroke are limited due to the heterogeneity of cerebral ischemic injury and the mechanisms that contribute to the cell death. Since oxidative stress is one of the primary mechanisms that cause brain injury post-stroke, we hypothesized that therapeutic targets that modulate mitochondrial function could protect against reperfusion-injury after cerebral ischemia, with the focus here on a mitochondrial protein, mitoNEET, that modulates cellular bioenergetics.

METHOD

In this study, we evaluated the pharmacology of the mitoNEET ligand NL-1 in an in vivo therapeutic role for NL-1 in a C57Bl/6 murine model of ischemic stroke.

RESULTS

NL-1 decreased hydrogen peroxide production with an IC50 of 5.95 μM in neuronal cells (N2A). The in vivo activity of NL-1 was evaluated in a murine 1 h transient middle cerebral artery occlusion (t-MCAO) model of ischemic stroke. We found that mice treated with NL-1 (10 mg/kg, i.p.) at time of reperfusion and allowed to recover for 24 h showed a 43% reduction in infarct volume and 68% reduction in edema compared to sham-injured mice. Additionally, we found that when NL-1 was administered 15 min post-t-MCAO, the ischemia volume was reduced by 41%, and stroke-associated edema by 63%.

CONCLUSION

As support of our hypothesis, as expected, NL-1 failed to reduce stroke infarct in a permanent photothrombotic occlusion model of stroke. This report demonstrates the potential therapeutic benefits of using mitoNEET ligands like NL-1 as novel mitoceuticals for treating reperfusion-injury with cerebral stroke.

Mechanistic insights into the protective effect of paracetamol against rotenone-induced Parkinson's disease in rats: Possible role of endocannabinoid system modulation

Parkinson's disease (PD) is a disabling progressive neurodegenerative disease. So far, PD's treatment remains symptomatic with no curative effects. Aside from its blatant analgesic and antipyretic efficacy, recent studies highlighted the endowed neuroprotective potentials of paracetamol (PCM). To this end: the present study investigated: (1) Possible protective role of PCM against rotenone-induced PD-like neurotoxicity in rats, and (2) the mechanisms underlying its neuroprotective actions including cannabinoid receptors' modulation. A dose-response study was conducted using three doses of PCM (25, 50, and 100 mg/kg/day, i.p.) and their effects on body weight changes, spontaneous locomotor activity, rotarod test, tyrosine hydroxylase (TH) and α-synuclein expression, and striatal dopamine (DA) content were evaluated. Results revealed that PCM (100 mg/kg/day, i.p.) halted PD motor impairment, prevented rotenone-induced weight loss, restored normal histological tissue structure, reversed rotenone-induced reduction in TH expression and striatal DA content, and markedly decreased midbrain and striatal α-synuclein expression in rotenone-treated rats. Accordingly, PCM (100 mg/kg/day, i.p.) was selected for further mechanistic investigations, where it ameliorated rotenone-induced oxidative stress, neuro-inflammation, apoptosis, and disturbed cannabinoid receptors' expression. In conclusion, our findings imply a multi-target neuroprotective effect of PCM in PD which could be attributed to its antioxidant, anti-inflammatory and anti-apoptotic activities, in addition to cannabinoid receptors' modulation.

Naringin Supplementation during Pregnancy Induces Sex and Region-Specific Alterations in the Offspring's Brain Redox Status

Research has shown the beneficial effects of naringin supplementation to adult rodents, which can ameliorate oxidative stress in disease models. However, evidence has demonstrated that polyphenol supplementation induced detrimental effects when consumed during sensitive periods of development, such as pregnancy. Therefore, we investigated the effect of maternal naringin supplementation during pregnancy on the offspring’s cerebral redox status. Pregnant Wistar rats were divided into control and naringin groups and supplemented from gestational day 15 to gestational day 21. On postnatal days 1, 7, and 21, offspring were euthanized, and the prefrontal cortex, hippocampus, striatum, and cerebellum dissected. On postnatal day 1, maternal naringin supplementation positively modulated the pups’ brain redox status. On postnatal day 7, a pro-oxidative milieu was observed in the offspring’s striatum and cerebellum in a sex-dependent manner, even though the prefrontal cortex and hippocampus were not negatively affected. Besides, the alterations observed on postnatal day 7 did not persist up to weaning. Our findings demonstrated that the effect induced by naringin supplementation in the brain redox status differed according to the period of development in which naringin was consumed since the beneficial effects usually found in the adult rodents became detrimental when the supplementation was applied during pregnancy.

Isolation and Characterization of Neuroprotective Components from Citrus Peel and Their Application as Functional Food

The elderly experience numerous physiological alterations. In the brain, aging causes degeneration or loss of distinct populations of neurons, resulting in declining cognitive function, locomotor capability, etc. The pathogenic factors of such neurodegeneration are oxidative stress, mitochondrial dysfunction, inflammation, reduced energy homeostatis, decreased levels of neurotrophic factor, etc. On the other hand, numerous studies have investigated various biologically active substances in fruit and vegetables. We focused on the peel of citrus fruit to search for neuroprotective components and found that: 1) 3,5,6,7,8,3',4'-heptamethoxyflavone (HMF) and auraptene (AUR) in the peel of Kawachi Bankan (Citrus kawachiensis) exert neuroprotective effects; 2) both HMF and AUR can pass through the blood-brain barrier, suggesting that they act directly in the brain; 3) the content of AUR in the peel of K. Bankan was exceptionally high, and consequently the oral administration of the dried peel powder of K. Bankan exerts neuroprotective effects; and 4) intake of K. Bankan juice, which was enriched in AUR by adding peel paste to the raw juice, contributed to the prevention of cognitive dysfunction in aged healthy volunteers. This review summarizes our studies in terms of the isolation/characterization of HMF and AUR in K. Bankan peel, analysis of their actions in the brain, mechanisms of their actions, and trials to develop food that retains their functions.

Grapefruit-derived extracellular vesicles as a promising cell-free therapeutic tool for wound healing

Due to the prevalence of individuals suffering from chronic wounds, developing safe and effective wound care agents are one of the more prominent fields of research in biology. However, wound healing is a complex, multi-stage biological process, involving multiple sequences of biological responses from different types of cells, secreted mediators, and extracellular matrix elements. Plants have a long history of use in the treatment of wounds. Plant-derived extracellular vesicles, which are secreted nano vesicle messengers responsible for intercellular communications, show promise as a new, biotechnological wound-care agent. In this study, we assessed the wound healing potential of extracellular vesicles isolated from grapefruits - a plant with well-known anti-inflammatory and wound healing properties. Grapefruit extracellular vesicles (GEVs) increased cell viability and cell migration while reducing intracellular ROS production in a dose-dependent manner in HaCaT cells. Expression of proliferation and migration-related genes were raised by GEV treatment in a dose dependent manner. Additionally, GEV treatment increased the tube formation capabilities of treated HUVEC cells. These findings suggest that GEVs can be used as plant-derived wound healing agents, and have shown potential as a biotechnological agent for wound healing. Further development and study of plant-derived extracellular vesicles may lead to the realization of their full potential.

Galangin attenuated cerebral ischemia-reperfusion injury by inhibition of ferroptosis through activating the SLC7A11/GPX4 axis in gerbils

AIMS

To evaluate the impact of galangin treatment on cerebral ischemia-reperfusion (I/R) injury in gerbils and to identify potential mechanisms of the protective effect of galangin on hippocampal neurons after I/R injury.

PRINCIPAL METHODS

A cerebral ischemia model using bilateral common carotid artery ligation in gerbils was established. The Morris water maze (MWM) test was used to evaluate the learning and memory ability of gerbils. The cell viability was evaluated with an MTT assay. The levels of lipid peroxide biomarkers were measured to estimate the injury due to lipid peroxide. The morphology was detected by electron micrography, immunofluorescence and Nissl staining. Western blot and quantitative real-time polymerase chain reaction (qRT-PCR) were used to measure the molecular characteristics.

KEY FINDINGS

In the MWM, gerbils treated with galangin after I/R injury showed significant improvements in learning and memory. In addition, galangin treatment reduced the levels of lipid peroxide in the brains of gerbils that underwent I/R as well as reduced the amount of cell death and increased the expression of SLC7A11 and glutathione peroxidase 4 (GPX4). Furthermore, the expression of the marker of ferroptosis was decreased in galangin-treated gerbils, and the effect of galangin was weakened when SLC7A11 was knocked down. These results show that galangin can inhibit ferroptosis by enhancing the expressions of SLC7A11 and GPX4 as well as reduce neuronal cell death.

SIGNIFICANCE

Galangin inhibits ferroptosis through activation of the SLC7A11/GPX4 axis and has a protective effect on hippocampal neurons in gerbils after I/R.

Possible Pharmacodynamic Interaction of Azelnidipine with Citicoline Against Ischemic Brain Injury: Behavioral, Biochemical and Histological Alterations

BACKGROUND

Currently, no drug has been approved for the management of postischemic neuronal damage. Existing studies show that calcium channel blockers have neuroprotective properties, while citicoline is involved in maintaining neuronal integrity.

PURPOSE

This study was envisaged to investigate the effect of azelnidipine (novel calcium channel blocker) alone and in combination with citicoline (phosphatidyl-choline analogue) against ischemic brain damage in Wistar rats.

METHODS

Previously standardized bilateral common carotid artery occlusion model was used to induce cerebral ischemic injury in Wistar rats. Pretreatment with azelnidipine (1.5 mg/Kg and 3 mg/Kg; p.o.) or citicoline (250 mg/Kg; i.p.) was done every 24 h starting 7 days before the bilateral common carotid artery occlusion surgery. Pharmacological assessments (behavioral, biochemical, mitochondrial, molecular, and histological) were done after 48 h of the reperfusion period.

RESULTS

Azelnidipine and citicoline were found to protect the brain from progressive neuronal damage as seen by improved sensorimotor behavior (locomotion, rota rod, and beam balance performance) and reduced oxidative stress (decreased malondialdehyde (MDA), nitrite, increased glutathione (GSH), superoxide dismutase (SOD)). Impairment of mitochondrial enzyme system and increase in the infarct area were found to be arrested by individual treatments with azelnidipine and citicoline. These effects were further potentiated synergistically as the combination of citicoline and azelnidipine was found to decrease glutamate levels, caspase-3 activity and histological alterations as compared to their individual effects.

CONCLUSION

Azelnidipine and citicoline synergistically decrease excitotoxic and oxidative damage against ischemic brain injury in Wistar rats and, therefore, propose a clinically relevant combination for the prevention of postischemic neuronal damage.

The effect of pentadecapeptide BPC 157 on hippocampal ischemia/reperfusion injuries in rats

BACKGROUND AND PURPOSE

We focused on the, yet undescribed, therapy effect of the stable gastric pentadecapeptide BPC 157 in hippocampal ischemia/reperfusion injuries, after bilateral clamping of the common carotid arteries in rats. The background is the proven therapy effect of BPC 157 in ischemia/reperfusion injuries in different tissues. Furthermore, there is the subsequent oxidative stress counteraction, particularly when given during reperfusion. The recovering effect it has on occluded vessels, results with activation of the alternative pathways, bypassing the occlusion in deep vein thrombosis. Finally, the BPC 157 therapy benefits with its proposed role as a novel mediator of Roberts' cytoprotection and bidirectional effects in the gut-brain axis.

MATERIALS AND METHODS

Male Wistar rats underwent bilateral clamping of the common carotid arteries for a 20-min period. At 30 s thereafter, we applied medication (BPC 157 10 µg/kg; or saline) as a 1 ml bath directly to the operated area, that is, trigonum caroticum. We documented, in reperfusion, the resolution of the neuronal damages sustained in the brain, resolution of the damages reflected in memory, locomotion, and coordination disturbances, with the presentation of the particular genes expression in hippocampal tissues.

RESULTS

In the operated rats, at 24 and 72 hr of the reperfusion, the therapy counteracted both early and delayed neural hippocampal damage, achieving full functional recovery (Morris water maze test, inclined beam-walking test, lateral push test). mRNA expression studies at 1 and 24 hr, provided strongly elevated (Egr1, Akt1, Kras, Src, Foxo, Srf, Vegfr2, Nos3, and Nos1) and decreased (Nos2, Nfkb) gene expression (Mapk1 not activated), as a way how BPC 157 may act.

CONCLUSION

Together, these findings suggest that these beneficial BPC 157 effects may provide a novel therapeutic solution for stroke.

Naringin Targets NFKB1 to Alleviate Oxygen-Glucose Deprivation/Reoxygenation-Induced Injury in PC12 Cells Via Modulating HIF-1α/AKT/mTOR-Signaling Pathway

This study was designed to investigate the effect of naringin in oxygen-glucose deprivation/reoxygenation (OGD/R) model and its mechanism. The target gene of naringin and the enriched pathways of the gene were searched and identified using bioinformatics analysis. Then OGD/R model was built using PC12 cells, after which the cells were treated with different concentrations of naringin. Subsequently, cell proliferation and apoptosis were evaluated by cell counting kit-8 (CCK-8) and flow cytometry assays, respectively. Meanwhile, the expression of NFKB1 in PC12 cells underwent OGD/R-induced injury was detected by qRT-PCR, while apoptosis-related and pathway-related proteins were checked by Western blot. DCF-DA kit was utilized to measure the level of ROS. Our results revealed that NFKB1, which was upregulated in MACO rats and OGD/R-treated PC12 cells, was a target gene of naringin. Naringin could alleviate OGD/R-induced injury via promoting the proliferation, and repressing the apoptosis of PC12 cells through regulating the expression of NFKB1 and apoptosis-associated proteins and ROS level. Besides, the depletion of NFKB1 was positive to cell proliferation but negative to cell apoptosis. Moreover, the depletion of NFKB1 enhanced the influences of naringin on cell proliferation and apoptosis as well as the expression of apoptosis-related proteins and ROS level. Western blotting indicated that both naringin treatment and depletion of NFKB1 could increase the expression of HIF-1α, p-AKT, and p-mTOR compared with OGD/R group. What's more, treatment by naringin and si-NFKB1 together could significantly increase these effects. Nevertheless, the expression of AKT and mTOR among each group was almost not changed. In conclusion, naringin could prevent the OGD/R-induced injury in PC12 cells in vitro by targeting NFKB1 and regulating HIF-1α/AKT/mTOR-signaling pathway, which might provide novel ideas for the therapy of cerebral ischemia-reperfusion (I/R) injury.

Therapeutic targets of oxidative/nitrosative stress and neuroinflammation in ischemic stroke: Applications for natural product efficacy with omics and systemic biology

Oxidative/nitrosative stress and neuroinflammation are critical pathological processes in cerebral ischemia-reperfusion injury, and their intimate interactions mediate neuronal damage, blood-brain barrier (BBB) damage and hemorrhagic transformation (HT) during ischemic stroke. We review current progress towards understanding the interactions of oxidative/nitrosative stress and inflammatory responses in ischemic brain injury. The interactions between reactive oxygen species (ROS)/reactive nitrogen species (RNS) and innate immune receptors such as TLR2/4, NOD-like receptor, RAGE, and scavenger receptors are crucial pathological mechanisms that amplify brain damage during cerebral ischemic injury. Furthermore, we review the current progress of omics and systematic biology approaches for studying complex network regulations related to oxidative/nitrosative stress and inflammation in the pathology of ischemic stroke. Targeting oxidative/nitrosative stress and neuroinflammation could be a promising therapeutic strategy for ischemic stroke treatment. We then review recent advances in discovering compounds from medicinal herbs with the bioactivities of simultaneously regulating oxidative/nitrosative stress and pro-inflammatory molecules for minimizing ischemic brain injury. These compounds include sesamin, baicalin, salvianolic acid A, 6-paradol, silymarin, apocynin, 3H-1,2-Dithiole-3-thione, (-)-epicatechin, rutin, Dl-3-N-butylphthalide, and naringin. We finally summarize recent developments of the omics and systematic biology approaches for exploring the molecular mechanisms and active compounds of Traditional Chinese Medicine (TCM) formulae with the properties of antioxidant and anti-inflammation for neuroprotection. The comprehensive omics and systematic biology approaches provide powerful tools for exploring therapeutic principles of TCM formulae and developing precision medicine for stroke treatment.

Naringin provides neuroprotection in CCL2-induced cognition impairment by attenuating neuronal apoptosis in the hippocampus

Background

Chemokine C–C motif ligand 2 (CCL2) is one of the most widely recognised proinflammatory chemokines in cognitive disorders. Currently, CCL2-targeting drugs are extremely limited. Thus, this study aimed to explore the neuroprotection afforded by naringin in CCL2-induced cognitive impairment in rats.

Methods

Before the CCL2 intra-hippocampal injection, rats were treated with naringin for 3 consecutive days via intraperitoneal injection. Two days post-surgery, the Morris water maze (MWM) and novel object recognition (NORT) tests were performed to detect spatial learning and memory and object cognition, respectively. Nissl staining and dUTP nick-end labelling (TUNEL) staining were performed to assess histopathological changes in the hippocampus. Commercial kits were used to measure the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) and the content of malondialdehyde (MDA). Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to examine the relative mRNA expression of interleukin 1β, (IL-1β), interleukin 6 (IL-6), glutamate/aspartate transporter (GLAST), glutamate transporter-1 (GLT-1), phosphate-activated glutaminase (PAG), cysteine aspartic acid-specific protease 8 (caspase-8), cysteine aspartic acid-specific protease 3 (caspase-3), cell lymphoma/leukaemia-2 (Bcl-2), and Bcl-2 associated X protein (Bax).

Results

In the MWM, the average escape latency and average swimming distance were significantly reduced and the crossing times were increased in the naringin-treated groups, compared with the CCL2 group. The NORT results revealed that, compared with the CCL2 rats, the discrimination index in the naringin-treated rats increased significantly. Nissl and TUNEL staining revealed that naringin protected the structure and survival of the neurons in the CA1 zone of the hippocampus. In the naringin-treated groups, the SOD and GSH-Px activities were increased, whereas the MDA levels were decreased. Furthermore, in the naringin-treated groups, the relative mRNA expression of IL-1β and IL-6 was significantly decreased; GLAST and GLT-1 mRNA expression levels were increased, whereas PAG was decreased. In the naringin-treated groups, the relative mRNA expression levels of caspase-8, caspase-3, and Bax were decreased, whereas that of Bcl-2 was increased.

Conclusion

Collectively, these data indicated that naringin alleviated the CCL2-induced cognitive impairment. The underlying mechanisms could be associated with the inhibition of neuroinflammation, oxidative stress, apoptosis, and the regulation of glutamate metabolism.

The protective effect of cordyceps sinensis extract on cerebral ischemic injury via modulating the mitochondrial respiratory chain and inhibiting the mitochondrial apoptotic pathway

Cerebral ischemia is a common refractory brain disease, resulting from a reduction in the blood flow to the brain. Mitochondrial dysfunction leads to ischemic stroke and brain injury. Cordyceps sinensis (CS) is an important traditional Chinese medicine, which has been linked to neuroprotection in recent studies. In this study, we investigated the role of the mitochondrial respiratory chain and the mitochondrial apoptotic pathway on the protective effect of Cordyceps sinensis extract (CSE) against cerebral ischemia injury both in vivo and in vitro. In a murine middle cerebral artery occlusion (MCAO) model, administration of CSE relieved neuronal morphological damage and attenuated the neuronal apoptosis. CSE also reduced neurobehavioral scores and oxygen free radical (OFR), while improving the levels of ATP, cytochrome c oxidase (COX), and mitochondrial complexes I-IV. Furthermore, the mRNA expression of Bax, cytochrome c (Cyt c) and caspase-3 were down-regulated. In brain microvascular endothelial cells (BMECs) exposed to oxygen and glucose deprivation (OGD), CSE prevented OGD-induced cellular apoptosis, and recovered the reduction of mitochondrial membrane potential (MMP). Moreover, CSE treatment induced an increase of Bcl-2 protein expression and a decrease of Bax, Cyt c and caspase-3 protein expression. Meanwhile, the caspase-3, -8, and -9 activities were also inhibited. The results indicate that CSE can relieve cerebral ischemia injury and exhibit protective effects via modulating the mitochondrial respiratory chain and inhibiting the mitochondrial apoptotic pathway.

Protective effects of naringin and trimetazidine on remote effect of acute renal injury on oxidative stress and myocardial injury through Nrf-2 regulation

BACKGROUND

Ischemia/reperfusion (I/R) is the predominant cause of acute renal failure (ARF), which damages the remote organs, especially the heart, and subsequently leads to death. The aim of the current study was to examine the effects of naringin (NAR), trimetazidine (TMZ), or their combination on the Nrf-2 expression in the kidney tissue, and myocardial injury in the renal IR injury in rats.

METHODS

Forty male Sprague-Dawley rats were randomly separated into five groups as follows: sham, IR injury, TMZ (5 mg/kg, intravenously), NAR (100 mg/kg), and their combination. Renal I/R injury and ischemia were induced by using clamps for 45 min, and after 4 h reperfusion, respectively. Then, the Nrf-2 expression in the kidney, antioxidant activity (CAT, SOD, and GPx), total antioxidant capacity (TAC), oxidative stress, electrocardiogram (ECG) parameters, and biochemical markers were examined.

RESULTS

Renal IR injury significantly reduced the Nrf-2 expression, superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) enzymes' activities and TAC. Moreover, Malondialdehyde (MDA) level in kidney and heart tissues, plasma creatine kinase-MB (CK-MB), and lactate dehydrogenase (LDH) activity were increased, and ECG parameters were significantly distributed; however, NAR, TMZ, or their combination improved these changes, in comparison with the renal IR injury in rats.

CONCLUSION

NAR, TMZ, or their combination could attenuate the Nrf-2 expression in the kidney tissue, following the renal IR injury through inhibition of lipid peroxidase, and enhancement of antioxidant activity.

Protective Effect of Naringin on Bisphenol A-Induced Cognitive Dysfunction and Oxidative Damage in Rats

Bisphenol A (BPA) is one of the highest volume chemicals produced worldwide, which is used in many plastic industries. The present study aimed to evaluate the effect of BPA on cognitive functions and oxidative stress, and determine whether the naringin (NG) co-administration can modify the effect of this compound on cognitive functions and inhibit any possible oxidative stress in the brain tissue of rats. Adult male Wistar rats were divided into six groups. Group I: control, Group II: BPA-treated rats (50 mg/kg/day), Group III, IV, V: BPA+NG (40, 80, 160 mg/kg/day), Group VI: NG (160 mg/kg/day) alone. Cognitive functions were evaluated using step-down latency (SDL) on a passive avoidance apparatus, and transfer latency (TL) in elevated plus-maze. A significant decrease in SDL, prolongation of TL, noticeable oxidative impairment and increase in acetylcholinesterase activity were observed in the BPA-treated in comparison with the control group. Also, the co-administration of NG (160 mg/kg) antagonized the effect of BPA on SDL and TL, attenuated oxidative damage by lowering malondialdehyde and nitrite concentrations and restored superoxide dismutase, catalase, and glutathione S-transferase activities. On the other hand, acetylcholinesterase activity was reduced in the groups co-administred with NG (80 or 160 mg/kg) and BPA in comparison with the BPA alone-treated group. The present study highlighted the therapeutic potential of NG against BPA-induced cognitive impairment and oxidative damage.

Temporal changes in physiological and molecular markers in various brain regions following transient global ischemia in rats

Several mechanisms are involved in the loss of cellular integrity and tissue destructions in various brain regions during ischemic insult. The affected brain employs various self-repair mechanisms during the poststroke recovery. Therefore, the current study involves time course changes in different brain regions following ischemia in terms of inflammation, oxidative stress and apoptosis for which a bilateral common carotid arteries occlusion model was chosen. The development of oxidative stress was seen with a marked increase in ROS and NO levels with concomitant decrease in GSH levels and also the activities of anti-oxidant enzymes. These alterations were accompanied with decreased levels of neurotransmitters and motor and cognitive deficits at various time points. Increased expressions of various pro-inflammatory cytokines and a decline in BDNF levels in hippocampal regions on 7th day post ischemia, suggesting their role in its pathogenesis. The restoration of BDNF and neurotransmitter levels along with significant decline in inflammatory cytokine levels 14th day onwards following ischemia in hippocampus suggested poststroke recovery. The extent of neuronal damage was found to be increased significantly on 7th day post ischemia as indicated by TUNEL assay and hematoxylin and eosin staining depicting enhanced number of pyknotic neurons in cortical and hippocampal regions. Cortical regions of the ischemic brains were severely affected while hippocampal regions showed significant poststroke recovery, which might attributed to the normalization of BDNF and pro-inflammatory cytokine levels. In conclusion, the present study established the central role of BDNF and pro-inflammatory cytokines in the poststroke recovery. Also, the cortical and hippocampal regions were found to be more susceptible for ischemic injury. As our results indicated, full recovery after ischemic injury in different brain regions was not achieved, therefore further studies with long-term recovery time are required to be conducted.

Therapeutic potential of naringin in neurological disorders

Neurological illnesses are multifactorial incurable debilitating disorders that may cause neurodegeneration. These diseases influence approximately 30 million people around the world. Despite several therapies, effective management of such disorders remains a global challenge. Thus, natural products might offer an alternative therapy for the treatment of various neurological disorders. Polyphenols, such as curcumin, resveratrol, myricetin, mangiferin and naringin (NRG) have been shown to possess promising potential in the treatment of neurogenerative illness. In this review, we have targeted the therapeutic potential of naringin as a neuroprotective agent. The overall neuroprotective effects and different possible underlying mechanisms related to NRG are discussed. In light of the strong evidence for the neuropharmacological efficacy of NRG in various experimental paradigms, it is concluded that this molecule should be further considered and studied as a potential candidate for neurotherapeutics, focusing on mechanistic and clinical trials to ascertain its efficacy.

The renoprotective effects of naringin and trimetazidine on renal ischemia/reperfusion injury in rats through inhibition of apoptosis and downregulation of micoRNA-10a

Renal Ischemia-Reperfusion (IR) injury occurs due to circulatory shock and renal transplantation, leading to mortality and morbidity worldwide. The primary purpose of the current study was to evaluate the renoprotective effects of the naringin (NAR) and trimetazidine (TMZ) on IR injury, renal hemodynamics, antioxidant capacity, microRNA-10a, and expression of apoptosis factors. Forty rats were divided into five groups randomly: Sham, IR injury, (TMZ, 5 mg/kg), (NAR pretreatment, 100 mg/kg), and TMZ plus NAR. The sham group underwent the identical surgical procedure as the other groups, except for the application of clamps. After anesthesia, IR injury was induced by 45 min of ischemia, followed by reperfusion for 4 h. Tissue and blood samples were collected for evaluation of renal function, antioxidant activity and, biochemical and molecular parameters. Administration of the NAR, TMZ, and their combination decreased the plasma level of microRNA-10a, caspase-3, and Bcl-2 associated x protein (Bax) mRNA expression, but increased the B- cell lymphoma 2 (Bcl-2) mRNA expression in the kidney tissue. In addition, antioxidant activity, renal blood flow, creatinine clearance (C_Cr), and fractional excretion of sodium (FE_Na) were improved. The NAR, TMZ, and their combination can prevent renal I/R injury through promotion of the level of antioxidant enzymes, as well as decrease of microRNA-10a and anti-apoptosis properties. Our data also suggest that NAR, TMZ, or their combination might be beneficial as potent therapeutic factors against renal IR injury.

Effects of thrombolysis within 6 hours on acute cerebral infarction in an improved rat embolic middle cerebral artery occlusion model for ischaemic stroke

Recombinant tissue plasminogen activator (rt-PA) is the first-line drug for revascularization in acute cerebral infarction (ACI) treatment. In this study, an improved rat embolic middle cerebral artery occlusion model for ischaemic stroke was used and the rats were killed on the first, third and seventh day after model establishment. Increases in infarct volume were significantly less in the thrombolytic group than in the conventional group at every time-point. The microvascular density (MVD) in the thrombolytic group was significantly higher than that in the conventional group at every time-point, especially on the seventh day. Increases in the expressions of neuronal nitric-oxide synthase (NOS) and caspase-3 in the ischaemic region and in the nitric oxide contents, malondialdehyde contents, and inducible NOS activities in the cortex of infarct side were significantly less in the thrombolytic group than in the conventional group. Furthermore, decreases in the superoxide dismutase activities in the thrombolytic group were significantly less than those in the conventional group. In conclusion, thrombolytic rt-PA therapy within a broadened therapeutic window (6 hours) could significantly decrease the infarct volume after ACI, possibly by increasing MVD in the ischaemic region, decreasing apoptotic molecule expression, and alleviating the oxidative stress response.

Investigation of the effects of naringin on intestinal ischemia reperfusion model at the ultrastructural and biochemical level

We aimed to evaluate the ultrastructural effect of reversing cellular damage, occurring in rats due to ischemia-reperfusion (I/R) in the intestine, with naringin implementation through biochemical parameters. Rats were divided the sham/control, I/R and the naringin groups (n = 7). For I/R group, 120 min of ischemia and 120 min of reperfusion was applied to the superior mesenteric artery. In the naringin group, after 120 min, 50 mg/kg naringin was implemented, and then 120 min of reperfusion was applied. Morphological evaluation was performed via Chiu score and electron microscopy. The antioxidant parameters were examined. Chiu score in I/R (p < 0.01) and naringin (p < 0.05) groups were higher than the sham/control group. In ultrastructural level some irregularity were observed in I/R group. Although it decreased in the naringin group, the damage was observed to continue. Malondialdehyde (MDA) amount and Superoxide dismutase activity (SOD) in I/R group were higher in comparison to the sham/control group (p < 0.01), while glutathione peroxidase activity (Gpx) was found to be lower (p < 0.01). SOD (p < 0.05) and MDA (p < 0.01) were decreased by naringin group. Gpx was decreased in I/R group compared to sham/control group (p < 0.01) and elevated due to naringin administration (p < 0.05). Catalase activity was observed to decrease in the naringin group compared to control and I/R groups (p < 0.01). It was determined that naringin provided limited healing at the ultrastructural level but also effected recovery within antioxidant parameters.

Effects of major ozonated autoheamotherapy on functional recovery, ischemic brain tissue apoptosis and oxygen free radical damage in the rat model of cerebral ischemia

Stroke is the second leading cause of death and disability in the world, with a heavy burden on patients, their families, and society. At present, a major focus of cerebrovascular disease research is to find a safe and effective new method to promote early functional recovery in the acute phase of cerebral infarction. Major ozonated autohemotherapy (MOAH) can maintain ATP and energy metabolism in cerebral ischemia and hypoxia, and reduce cell apoptosis. In the current study, the model of middle cerebral artery occlusion in the Sprague Dawley rat was established and evaluated by the clinical functional score, Hoechst staining, immunohistochemistry, Western blot analysis, and biochemical detection. Then, the effects of MOAH on neurological function, apoptosis, and oxygen free radical damage after acute ischemia in middle cerebral artery were evaluated. Moreover, the potential two mechanisms have been illustrated for MOAH effects. This study would lay a theoretical foundation for the application of MOAH and find an effective and early treatment method for the cerebral infarction.

Inhibitory Effects of Auraptene and Naringin on Astroglial Activation, Tau Hyperphosphorylation, and Suppression of Neurogenesis in the Hippocampus of Streptozotocin-Induced Hyperglycemic Mice

Auraptene, a citrus-related compound, exerts anti-inflammatory effects in peripheral tissues, and we demonstrated these effects in the brains of a lipopolysaccharide-injected systemic inflammation animal model and a brain ischemic mouse model. Naringin, another citrus-related compound, has been shown to exert antioxidant effects in several animal models. Hyperglycemia induces oxidative stress and inflammation and causes extensive damage in the brain; therefore, we herein evaluated the anti-inflammatory and other effects of auraptene and naringin in streptozotocin-induced hyperglycemic mice. Both compounds inhibited astroglial activation and the hyperphosphorylation of tau at 231 of threonine in neurons, and also recovered the suppression of neurogenesis in the dentate gyrus of the hippocampus in hyperglycemic mice. These results suggested that auraptene and naringin have potential effects as neuroprotective agents in the brain.

Neuroprotective effect of Citrus kawachiensis (Kawachi Bankan) peels, a rich source of naringin, against global cerebral ischemia/reperfusion injury in mice

Cerebral ischemia/reperfusion is known to induce the generation of reactive oxygen species and inflammatory responses. Numerous studies have demonstrated that naringin (NGIN) has anti-oxidant and anti-inflammatory properties. We previously reported that Citrus kawachiensis contains a large quantity of NGIN in its peel. In the present study, we orally (p.o.) administered dried peel powder of C. kawachiensis to mice of a transient global ischemia model and found in the hippocampus region that it 1) suppressed neuronal cell death, 2) reversed the reduction in the level of phosphorylated calcium-calmodulin-dependent protein kinase II, 3) had the tendency to reverse the reduction in the level of glutathione, and 4) blocked excessive activation of microglia and astrocytes. These results suggested that the dried peel powder of C. kawachiensis had a neuroprotective effect against ischemic brain via anti-oxidative and anti-inflammatory effects. We also showed that these effects of the dried peel powder were more powerful than those obtained with a comparable amount of NGIN alone.

Early changes in transient adenosine during cerebral ischemia and reperfusion injury

Adenosine is an important neuromodulator in the central nervous system, and tissue adenosine levels increase during ischemic events, attenuating excitotoxic neuronal injury. Recently, our lab developed an electrochemical fast-scan cyclic voltammetry (FSCV) method that identified rapid, spontaneous changes in adenosine concentrations that last only about 3 seconds. Here, we investigated the effects of cerebral ischemia and reperfusion on the concentration and frequency of transient adenosine release in the caudate-putamen. In anesthetized rats, data were collected for four hours: two hours of normoxia, 30 min of cerebral ischemia induced by bilateral common carotid artery occlusion, and 90 min of reperfusion. Transient adenosine release was increased during the cerebral ischemia period and remained elevated during reperfusion. The total number of adenosine transients increased by 52% during cerebral ischemia and reperfusion compared to normoxia. The concentration of adenosine per event did not increase but the cumulative adenosine concentration during cerebral ischemia and reperfusion increased by 53% because of the higher frequency of events. Further, we evaluated the role of A_2A antagonist, SCH442416, a putative neuroprotective agent to affect adenosine transients. SCH442416 significantly decreased the transient frequency during cerebral ischemia-reperfusion by 27% and the cumulative concentration by 31%. Our results demonstrate that this mode of rapid adenosine release increases during early cerebral ischemia-reperfusion injury. Rapid adenosine release could provide fast, local neuromodulation and neuroprotection during cerebral ischemia.

The beneficial role of Naringin- a citrus bioflavonoid, against oxidative stress-induced neurobehavioral disorders and cognitive dysfunction in rodents: A systematic review and meta-analysis

OBJECTIVES

Naringin is a bioflavonoid, very abundantly found in citrus species. In literature, naringin has been scientifically well documented for its beneficial effects in various neurological disorders. In this systematic review and meta-analysis, we have made an attempt to correlate the protective role of naringin against oxidative stress-induced neurological disorders in rodents.

METHODS

The systematic search was performed using electronic databases; the search was mainly focused on the role of naringin in oxidative stress-induced neuropathological conditions in rodents. While, the meta-analysis was performed on the effect of naringin on oxidative stress markers [superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST), reduced glutathione (GSH), lipid peroxidation (LPO)], nitrite, mitochondrial complexes (I to IV) and enzymes (acetylcholinesterase, Na⁺-K⁺-ATPase, Ca²⁺-ATPase, and Mg²⁺-ATPase) in the rodent brain. The data was analyzed using Review Manager Software.

THE RESULTS

Based on the inclusion and exclusion criteria, twenty studies were selected. The meta-analysis revealed that, naringin could significantly inhibit various physical and chemical stimuli- induced neurological perturbances in the rodent brain, mediated through oxidative stress. Further, naringin also significantly restored the levels of all the oxidative stress markers (oxidative, nitrosative, enzymes, and mitochondrial complexes) in different parts of the rodent brain.

SUMMARY

This systematic review and meta-analysis supports the available scientific evidence on the beneficial role of naringin in the management of various neurological ailments. However, further studies involving human subjects is recommended to establish the safety and therapeutic efficacy in humans.

Naringin Reverses Neurobehavioral and Biochemical Alterations in Intracerebroventricular Collagenase-Induced Intracerebral Hemorrhage in Rats

Intracerebral hemorrhage (ICH) contributes to 10-15% of all strokes and is a high risk factor for morbidity and mortality as compared to other subtypes of stroke, that is, cerebral ischemia and subarachnoid hemorrhage. Oxidative stress (OS)-induced neuroinflammation and neuronal cell death contribute towards the hallmarks of ICH. Spared antioxidant levels, increased inflammatory cytokines and free radicals in ICH lead to neuronal death and exaggerate the hallmarks of ICH. Intracerebroventricular (ICV) collagenase (COL-induced neuronal cell damage and cognitive deficits form a widely recognized experimental model for ICH. Naringin (NGN), a natural antioxidant bioflavonoid, has shown potent neuroprotective effects in different neurodegenerative diseases. However, its potential is least explored in pathological conditions, such as hemorrhagic stroke. This study is aimed at exploring the protective effects of NGN against ICV-COL induced behavioral, neurological and memory deficits in rats. ICV-ICH was induced by single, unilateral intrastriatal injection of COL (1 IU in 2 µL, ICV) over 10 min. From 2nd day onwards, NGN was administered in three different doses (10, 20, and 40 mg/kg; p.o.). Animals were subjected to a battery of behavioral tests to assess behavioral changes, including neurological scoring tests (cylinder test, spontaneous motility, righting reflex, horizontal bar test, forelimb flexion), actophotometer, rotarod, Randall Selitto and von Frey. Poststroke depression and memory deficits were estimated using forced swim test and Morris water maze test, respectively. Poststroke depression, neurological and cognitive deficits were mitigated dose dependently by NGN administration. NGN administration also attenuated the nitro-OS and restored tumor necrosis factor-α and endogenous antioxidant levels. Our research demonstrates that NGN has a protective effect against ICH-induced neurocognitive deficits, along with mitigation of oxido-nitrosative and inflammatory stress.

Naringin protects viscera from ischemia/reperfusion injury by regulating the nitric oxide level in a rat model

We investigated the effects of naringin on small intestine, liver, kidney and lung recovery after ischemia/reperfusion (I/R) injury of the gut. Rats were divided randomly into four groups of eight. Group A was the sham control; group B was ischemic for 2 h; group C was ischemic for 2 h and re-perfused for 2 h (I/R); group D was treated with 50 mg/kg naringin after ischemia, then re-perfused for 2 h. Endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) expressions were detected by immunolabeling. We also measured arginase activity, amounts of nitric oxide (NO) and total protein. iNOS was increased significantly in the small intestine, liver and kidney in group C. iNOS was decreased significantly only in small intestine and lung in group D. eNOS was increased significantly in the small intestine, liver and lung in group C. eNOS was decreased in small intestine, liver and lung in group D; however, eNOS was decreased in the kidney in group C and increased in the kidney in group D. The amount of NO was decreased significantly in all tissues in group D, but arginase activity was decreased in the small intestine and lung, increased in the kidney and remained unchanged in the liver in group D. The total protein increased in the small intestine and liver in group D, but decreased significantly in the kidney and lung in group D. Naringin had significant, salutary effects on the biochemical parameters of I/R by decreasing the NO level, equilibrating iNOS and eNOS expressions, and decreasing arginase activity.

Anti-Inflammation of Natural Components from Medicinal Plants at Low Concentrations in Brain via Inhibiting Neutrophil Infiltration after Stroke

Inflammation after stroke consists of activation of microglia/astrocytes in situ and infiltration of blood-borne leukocytes, resulting in brain damage and neurological deficits. Mounting data demonstrated that most natural components from medicinal plants had anti-inflammatory effects after ischemic stroke through inhibiting activation of resident microglia/astrocytes within ischemic area. However, it is speculated that this classical activity cannot account for the anti-inflammatory function of these natural components in the cerebral parenchyma, where they are detected at very low concentrations due to their poor membrane permeability and slight leakage of BBB. Could these drugs exert anti-inflammatory effects peripherally without being delivered across the BBB? Factually, ameliorating blood-borne neutrophil recruitment in peripheral circulatory system has been proved to reduce ischemic damage and improve outcomes. Thus, it is concluded that if drugs could achieve effective concentrations in the cerebral parenchyma, they can function via crippling resident microglia/astrocytes activation and inhibiting neutrophil infiltration, whereas the latter will be dominating when these drugs localize in the brain at a low concentration. In this review, the availability of some natural components crossing the BBB in stroke will be discussed, and how these drugs lead to improvements in stroke through inhibition of neutrophil rolling, adhesion, and transmigration will be illustrated.

Control of Granule Cell Dispersion by Natural Materials Such as Eugenol and Naringin: A Potential Therapeutic Strategy Against Temporal Lobe Epilepsy

The hippocampus is an important brain area where abnormal morphological characteristics are often observed in patients with temporal lobe epilepsy (TLE), typically showing the loss of the principal neurons in the CA1 and CA3 areas of the hippocampus. TLE is frequently associated with widening of the granule cell layer of the dentate gyrus (DG), termed granule cell dispersion (GCD), in the hippocampus, suggesting that the control of GCD with protection of hippocampal neurons may be useful for preventing and inhibiting epileptic seizures. We previously reported that eugenol (EUG), which is an essential component of medicinal herbs and has anticonvulsant activity, is beneficial for treating epilepsy through its ability to inhibit GCD via suppression of mammalian target of rapamycin complex 1 (mTORC1) activation in the hippocampal DG in a kainic acid (KA)-treated mouse model of epilepsy in vivo. In addition, we reported that naringin, a bioflavonoid in citrus fruits, could exert beneficial effects, such as antiautophagic stress and antineuroinflammation, in the KA mouse model of epilepsy, even though it was unclear whether naringin might also attenuate the seizure-induced morphological changes of GCD in the DG. Similar to the effects of EUG, we recently observed that naringin treatment significantly reduced KA-induced GCD and mTORC1 activation, which are both involved in epileptic seizures, in the hippocampus of mouse brain. Therefore, these observations suggest that the utilization of natural materials, which have beneficial properties such as inhibition of GCD formation and protection of hippocampal neurons, may be useful in developing a novel therapeutic agent against TLE.