Naringenin Pretreatment Research Articles

Naringenin Mitigates Dasatinib-Induced Kidney Damage by Modulating Antioxidant Defense, Inflammation, and Apoptosis Pathways.

Nephrotoxicity remains a significant concern associated with tyrosine kinase inhibitors, such as dasatinib (DASA). Previous studies have shown that DASA can induce renal tubular cell death, contributing to its nephrotoxic effects. In contrast, naringenin (NGN) is known for its antioxidant and anti-inflammatory properties. This study aimed to explore the nephroprotective potential of NGN against acute kidney injury induced by DASA in a mouse model. Mice were pre-treated with different doses of NGN (50, 100 mg/kg) for one week, followed by a single dose of DASA (25 mg/kg) on the 8th day. Results demonstrated that DASA significantly increased serum levels of blood urea nitrogen, creatinine, uric acid, and lactate dehydrogenase, which were effectively attenuated by NGN pretreatment. Furthermore, kidney tissues exposed to DASA exhibited elevated malondialdehyde (MDA) levels, which were significantly reduced by NGN. NGN also restored depleted levels of antioxidants (glutathione (GSH) and catalase (CAT)) in kidney tissues following DASA treatment. Additionally, NGN mitigated the upregulation of pro-inflammatory cytokines (TNF-α, NF-κB, and IL-6) induced by DASA, indicating an anti-inflammatory effect. Notably, DASA treatment upregulated the gene expression of the pro-apoptotic gene BAX while downregulating the expression of BCL-2 and Caspase-3 in kidney tissues. These findings suggest that NGN exerts nephroprotective effects against DASA-induced nephrotoxicity through its antioxidant, anti-inflammatory, and anti-apoptotic properties. Further investigations are warranted to elucidate the underlying mechanisms involved.

Protective effects of naringenin against methamphetamine-induced cell death in dopaminergic SH-SY5Y cells

ABSTRACT Background: Methamphetamine is a psychoactive substance that competes with the dopamine transporter, disrupting its flow and storage. This can trigger oxidative stress, finally resulting in neural cell death. Due to the increasing prevalence of methamphetamine use, extensive research has been devoted to finding treatments that ameliorate its detrimental effects. Naringenin, a dietary flavonoid found in citrus fruits, has shown several neuroprotective and pharmacological properties. Objectives: This study was aimed to assess the protective effects of naringenin against methamphetamine-induced dopaminergic cell death. Methods: Before exposure to methamphetamine, human neuroblastomaSH-SY5Y cells were either pretreated or not treated (controls) with naringenin. Cell viability, level of oxidative stress markers, and expression of some genes involved in apoptosis and autophagy processes were then assessed using MTT, ROS, and MMP assays, and qRT-PCR and Western blotting techniques. Results: Naringenin pretreatment significantly enhanced cell viability following methamphetamine exposure (p < .01). It significantly decreased ROS levels (p < .001), preserved mitochondrial membrane potential, and moderated upregulation of apoptotic (CytC, Casp3, and Bax) and autophagic genes (Beclin-1, and LC-3) and down-regulation of Bcl-2 as an anti-apoptotic gene. Similar naringenin-mediated patterns were observed for cytochrome C and caspase 3 proteins. Conclusion: Naringenin administration can be considered for treating the neurotoxic effects of methamphetamine.

"Behavioral rescue: Naringenin's neuroprotective effects against PTZ-induced seizures by mitigating oxidative stress and neuroinflammation in zebrafish larvae"

"Behavioral rescue: Naringenin's neuroprotective effects against PTZ-induced seizures by mitigating oxidative stress and neuroinflammation in zebrafish larvae"

Pharmacokinetics of Dasatinib in Rats: a Potential Food-Drug Interaction with Naringenin.

The novel tyrosine kinase inhibitor (TKI) dasatinib, a multitarget inhibitor of Bcr-Abl and Src family kinases, has been licensed for the treatment of Ph+ acute lymphoblastic leukemia and chronic myeloid leukemia. Many citrus-based foods include the flavonoid naringenin, which is commonly available. Dasatinib is a Cyp3a4, P-gp, and Bcrp1 substrate, which makes it sensitive to potential food-drug interactions. The concurrent use of naringenin may change the pharmacokinetics of dasatinib, which could result in adverse effects and toxicity. The present investigation examined the impact of naringenin on the pharmacokinetics interactions of DAS and proposes a possible interaction mechanism in Wistar rats. Rats were provided with a single oral dose of dasatinib (25mg/kg) with or without naringenin pretreatment (150mg/kg p.o. daily for 7days, n = 6 in each group). Dasatinib was quantified in plasma by UHPLC MS/MS assay. Noncompartmental analysis was used to compute the pharmacokinetic parameters, and immunoblot was used to assess the protein expression in the hepatic and intestinal tissues. Following 7 days of naringenin pretreatment, the plasma mean concentration of dasatinib was enhanced compared with without pretreatment. In rats that were pretreated with naringenin, the pharmacokinetics of the orally administered dasatinib (25mg/kg) was shown to be significantly different from that of dasatinib given without pretreatment (p < 0.05). There was a significant enhancement in pharmacokinetic parameterselimination half-life (T1/2),time to maximum concentration ( Tmax), maximum concentration )Cmax), area under the concentration-time curve (AUC0-t),area under the moment curve (AUMC0-∞), and mean residence time (MRT) by 28.41%, 50%, 103.54%, 72.64%, 115.08%, and 15.19%, respectively (p < 0.05) and suppression in elimination rate constant (Kel), volume of distribution (Vd), and clearance (CL) by 21.09%, 31.13%, and 46.25%, respectively, in comparison with dasatinib alone group (p < 0.05). The enhancement in dasatinib bioavailability and systemic exposure resulted from the significant inhibition of Cyp3a2, Mdr1/P-gp, and Bcrp1 expression and suppression of the dasatinib hepatic and intestinal metabolism, which enhanced the rate of dasatinib absorption and decreased its elimination. Concurrent use of naringenin-containing supplements, herbs, or foods with dasatinib may cause serious and potentially life-threatening drug interactions. Further studies are necessary to determine the clinical significance of these findings.

Supportive effect of naringenin on NaCl-induced toxicity in Carthamus tinctorius seedlings

In the present study, we used exogenous naringenin (0.5 mM) pretreatment before the stress (25 mM NaCl) on the growth and tolerance of safflower seedlings under non-salinity conditions and salinity conditions. Our results showed that salinity treatment significantly declined the biomass, leaf relative water content, chlorophyll content, K+ content, and K+/Na+ ratio by 28%, 28%, 12%, 36%, and 56%, respectively, as compared to untreated control. The results obtained in the present study showed the beneficial effects of the pretreatment of naringenin in safflower seedlings under non-salinity conditions concerning increasing plant biomass, total phenolic compound, radical scavenging activity (RSA), soluble sugar content, proline, glutathione, enzymatic antioxidants, and K+ content. Nevertheless, naringenin pretreated plants showed a clear increment in the values of biomass, RSA, total phenolic compound, and catalase enzyme activity parameters under salinity stress. Salinity stress caused ionic phytotoxicity and oxidative stress by enhancing Na+ content, H2O2 accumulation, malondialdehyde (MDA), and antioxidants. However, naringenin alleviated salt-induced oxidative stress by decreasing H2O2 and MDA content in the leaves and improving the catalase activity in treated plants. Generally, it could be concluded pretreatment of naringenin before stress could partly diminish NaCl-caused oxidative stress in safflower seedlings, probably due to improvement in enzymatic and non-enzymatic antioxidants and reduced cell membrane damage.

Uptake and Transport of Naringenin and Its Antioxidant Effects in Human Intestinal Epithelial Caco-2 Cells.

Naringenin, a flavanone, has been reported for a wide range of pharmacological activities. However, there are few reports on the absorption, transport and antioxidant effects of naringenin. The study was to explore the uptake, transport and antioxidant effects of naringenin in vitro. Cell transmembrane resistance, lucifer yellow transmission rate, and alkaline phosphatase activity were used to evaluate the successful construction of cell model. The results showed that the absorption and transport of naringenin by Caco-2 cells were time- and concentration-dependent. Different temperatures (37 and 4°C) had a significant effect on the uptake and transport of naringenin. Verapamil, potent inhibitor of P-glycoprotein, significantly inhibit naringenin transport in Caco-2 cells. The results revealed that naringenin was a moderately absorbed biological macromolecule and can penetrate Caco-2 cells, mainly mediated by the active transport pathway involved in P-glycoprotein. At the same time, naringenin pretreatment could significantly increase the viability of H2O2-induced Caco-2 cells. Twenty four differential metabolites were identified based on cellular metabolite analysis, mainly including alanine, aspartate and glutamate metabolism, histidine metabolism, taurine and hypotaurine metabolism, pyruvate metabolism, purine metabolism, arginine biosynthesis, citrate cycle, riboflavin metabolism, and D-glutamine and D-glutamate metabolism. We concluded that the transport of naringenin by Caco-2 cells is mainly involved in active transport mediated by P-glycoprotein and naringenin may play an important role in oxidative stress-induced intestinal diseases.

Naringenin affords protection against lipopolysaccharide/D-galactosamine-induced acute liver failure: Role of autophagy

Acute liver failure (ALF) is considered a fatal clinical disorder and novel therapeutic interventions are mandatory. Naringenin is a flavonoid with anti-inflammatory, antioxidant and antiapoptotic effects that have displayed beneficial effects in different animal models of ALF. The current study aimed at investigating the hepatoprotective effect and the possible underlying molecular mechanisms of naringenin in lipopolysaccharide (LPS)/D-galactosamine (D-Gal) mouse model of ALF. Interestingly, naringenin pretreatment substantially alleviated LPS/D-Gal-induced liver injury, enhanced survival, improved liver function and ameliorated histopathological liver changes. Importantly, naringenin potently activated autophagy as evidenced by the increased Beclin-1 expression and LC3 II/LC3 I ratio. Furthermore, results demonstrated that naringenin alleviated oxidative stress by inducing nuclear factor-erythroid 2-related factor 2 (Nrf2) and increasing hepatic SOD activity and GSH level as well as ameliorated endoplasmic reticulum (ER) stress. Likewise, naringenin mitigated LPS/D-Gal-triggered inflammation by suppressing NF-κB and NLRP3 pathways. Accordingly, apoptotic cell death provoked by LPS/D-Gal challenge was markedly attenuated as depicted by the decrease in caspase-3 and p53 in naringenin-treated mice. To investigate the contribution of autophagy to naringenin-conferred hepatoprotection, autophagy was inhibited using 3-methyladenine (3MA). Strikingly, 3MA co-treatment abolished the hepatoprotective effect of naringenin, a finding that strongly suggests that naringenin-afforded protection is, at least in part, attributed to autophagy. Taken together, the present study revealed that naringenin exerted a prominent hepatoprotective effect by promoting autophagy with consequent attenuation of inflammatory responses, oxidative stress, ER stress and apoptosis. Our results provide evidence that naringenin use holds a promise as a potential therapeutic agent for ALF management.

Naringenin protects AlCl3/D-galactose induced neurotoxicity in rat model of AD via attenuation of acetylcholinesterase levels and inhibition of oxidative stress

Currently prescribed medications for the treatment of Alzheimer’s disease (AD) that are based on acetylcholinesterase inhibition only offer symptomatic relief but do not provide protection against neurodegeneration. There appear to be an intense need for the development of therapeutic strategies that not only improve brain functions but also prevent neurodegeneration. The oxidative stress is one of the main causative factors of AD. Various antioxidants are being investigated to prevent neurodegeneration in AD. The objective of this study was to investigate the neuroprotective effects of naringenin (NAR) against AlCl3+D-gal induced AD-like symptoms in an animal model. Rats were orally pre-treated with NAR (50 mg/kg) for two weeks and then exposed to AlCl3+D-gal (150 mg/kg + 300 mg/kg) intraperitoneally for one week to develop AD-like symptoms. The standard drug, donepezil (DPZ) was used as a stimulator of cholinergic activity. Our results showed that NAR pre-treatment significantly protected AD-like behavioral disturbances in rats. In DPZ group, rats showed improved cognitive and cholinergic functions but the neuropsychiatric functions were not completely improved and showed marked histopathological alterations. However, NAR not only prevented AlCl3+D-gal induced AD-like symptoms but also significantly prevented neuropsychiatric dysfunctions in rats. Results of present study suggest that NAR may play a role in enhancing neuroprotective and cognition functions and it can potentially be considered as a neuroprotective compound for therapeutic management of AD in the future.

Neuroprotective role of naringenin against methylmercury induced cognitive impairment and mitochondrial damage in a mouse model

Human exposure to organomercurials like methylmercury (MeHg) may occur by consumption of contaminated seafood, affecting various vital organs especially, brain contributing to neuro disorders. The citrus flavanone, naringenin (NAR) has shown strong antioxidant and anti-inflammatory effects and therefore may exert cytoprotective effect against xenobiotic agents. Herein, we investigated the neuroprotective role of NAR against MeHg induced functional changes in mitochondria, neuronal cell death and cognitive impairment in a mouse model. A neurotoxic dose of MeHg (4 mg/kg.b.wt.) was administered orally to mice for 15 days. This resulted in the reduction of GSH and GST, an increase in mitochondrial DNA damage and memory impairment. On the contrary, NAR pre-treatment (100 mg/kg.b.wt.), helped in lowering the oxidative burden which in turn maintained mitochondrial function and prevented induced neuronal cell death, ultimately improving the cognitive impairment. As MeHg intoxication occurs chronically, consumption of the dietary components rich in NAR may have its positive human health impact, ultimately improving the quality of life.

Antidepressant and Neuroprotective Effects of Naringenin via Sonic Hedgehog-GLI1 Cell Signaling Pathway in a Rat Model of Chronic Unpredictable Mild Stress.

Depression is one of the most prevalent and crucial public health problem connected to significant mortality and co-morbidity. Recently, numerous studies suggested that dietary flavanones exhibit neuroprotective and antidepressant effects against various psycho-physiological conditions including depression. The present study is focused on the antidepressant and neuroprotective effects of naringenin (NAR) and the involvement of sonic hedgehog (Shh) signaling in the chronic unpredictable mild stress (CUMS)-induced depression. Twenty-four male Wistar rats were randomly assigned into four groups: CON group (saline s.c.), NAR group (NAR 50mg/kg, p.o.), CUMS group (subjected to CUMS along with saline p.o.), and CUMS + NAR group (NAR 50mg/kg p.o. along with CUMS) for 28days including 1-week pre-treatment with NAR. The results showed that NAR was found to inhibit behavioral abnormalities including increased despair in force swim test, and reduced locomotor activity caused by CUMS in open field test. Moreover, Morris water maze revealed that NAR also mitigates CUMS-associated cognitive impairment. In addition to the antidepressant-like effect, NAR mitigates morphological anomalies in the hippocampal CA1 region and cortex. Furthermore, we observed brain-derived neurotrophic factor (BDNF), Shh, GLI1, NKX2.2, and PAX6 were downregulated in the hippocampus of CUMS-exposed rats, which can be upregulated by NAR pre-treatment. GLI1 is main downstream signaling component of Shh signaling cascade, which further regulates the expression of homeodomain transcription factors PAX6 and NKX2.2.

Naringin ameliorates doxorubicin-induced neurotoxicity In vitro and cognitive dysfunction In vivo

Objectives: The primary objective of the study was to study the neuroprotective potential of naringin (NAR) against doxorubicin (DOX)-induced neurotoxicity in vitro and DOX-induced cognitive deficits (chemobrain) in vivo. Materials and Methods: In vitro methods, viz., 3-[4,5dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide assay, flow cytometry, acridine orange/ethidium bromide staining, and neuritogenic and reactive oxygen species (ROS) assays, assessed neuroprotective potential of NAR and its aglycone naringenin (NGN) in IMR-32 cells. Chemobrain was developed in Wistar rats on chronic administration of ten cycles of DOX, and episodic memory was assessed using novel object recognition task. Serum cortisol, locomotor activity, and hematological biochemical and histological analysis were carried out. Results: A protective effect of NAR or NGN was observed upon pretreatment with the respective compounds in IMR-32 cells challenged with DOX. Flow cytometry revealed that flavonoids reduced cell cycle changes produced by DOX. In addition, an increase in apoptosis, intracellular ROS generation, and inhibition of neurite growth was noticed in IMR-32 cells with DOX treatment, which was significantly prevented by NAR or NGN pretreatment. Interestingly, NAR (50 mg/kg, p.o.) significantly ameliorated episodic memory deficit associated with DOX without influencing locomotion, upon chronic treatment. NAR also prevented histological changes to major organs observed with DOX. Conclusion: NAR showed neuroprotective potential and may be used as an adjuvant therapy for amelioration of neurocognitive complications associated with chemotherapy in cancer survivors. Abbreviations used: CKL: Creatine kinase level; COX: Cyclooxygenase; DMEM: Dulbecco's modified eagle media; DOX: Doxorubicin; FBS: Fetal bovine serum; MTT: 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide; NAR: Naringin; NGN: Naringenin; NORT: Novel object recognition task; NOS: Nitric oxide synthase; QOL: Quality of life; RA: retinoic acid.

Naringenin ameliorates LPS-induced acute lung injury through its anti-oxidative and anti-inflammatory activity and by inhibition of the PI3K/AKT pathway.

The aim of the present study was to explore the effect of naringenin on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in a mouse model, as well as the underlying mechanism. The animals were randomly assigned to four groups: PBS-treated healthy control (Control), LPS-induced ALI (LPS), vehicle-treated ALI (LPS + Vehicle), and naringenin-treated ALI (LPS + Nar) group. Naringenin (100 mg/kg) was administered orally for 4 consecutive days, starting 3 days prior to induction of ALI. The survival rates of mice, lung wet/dry weight ratios, lung injury score, protein levels of bronchoalveolar lavage fluid (BALF), lactate dehydrogenase (LDH) activity in the BALF, lung myeloperoxidase (MPO) activity, the number of infiltrated neutrophils and reactive oxygen species (ROS) levels (H2O2 and malondialdehyde) were assessed. In addition, the serum and BALF levels of inflammatory cytokines [tumor necrosis factor-α, interleukin (IL)-1β, IL-6 and macrophage inflammatory protein 2] were determined, along with the total and the phosphorylated protein levels of phosphatidylinositol 3-hydroxy kinase (PI3K) and AKT in lung tissues. The results showed that naringenin pre-treatment significantly increased the survival rate, improved histopathologic changes, alleviated pulmonary edema and lung vascular leak, downregulated the levels of ROS and reduced neutrophil infiltration as well as the levels of inflammatory cytokines in the serum and BALF. Moreover, naringenin pre-treatment reduced the total and the phosphorylated protein levels of PI3K and AKT. The present study suggested that naringenin pre-treatment ameliorated LPS-induced ALI through its anti-oxidative and anti-inflammatory activity and by inhibition of the PI3K/AKT pathway in mice.

Naringenin pre-treatment inhibits neuroapoptosis and ameliorates cognitive impairment in rats exposed to isoflurane anesthesia by regulating the PI3/Akt/PTEN signalling pathway and suppressing NF-κB-mediated inflammation.

The volatile anaesthetic isoflurane is one of the most frequently employed general anaesthetics in neonates, children and adults. Accumulating evidence demonstrated that exposure to anaesthetics is associated with widespread neurodegeneration and cognitive impairment. Thus, the identification and development of compounds capable of preventing or reducing these adverse effects is of great clinical importance. For this purpose, the present study aimed to assess the effects of a flavonoid, naringenin, on isoflurane-induced neuroapoptosis and cognitive impairment. Separate groups of neonatal rat pups were administered naringenin at 25, 50 or100mg/kg body weight from postnatal day 1(P1) to P21. On P7, the pups were exposed to 6h of isoflurane (0.75%) anaesthesia. Neuroapoptosis was examined using the TUNEL assay. The expression of cleaved caspase-3, the apoptotic pathway proteins (Bad, Bax, Bcl-2 and Bcl-xL), the phosphoinositide 3-kinase(PI3K)/protein kinase B(Akt) pathway proteins [Akt, phosphorylated(-)Akt, glycogen synthase kinase3β(GSK‑3β), p‑GSK-3β, phosphatase and tensin homolog(PTEN)] and nuclear factor-κB(NF-κB)‑mediated signalling proteins were determined by western blot analysis. General behaviour, as well as the learning ability and memory of the pups were assessed. Naringenin significantly inhibited isoflurane‑induced neuroapoptosis and markedly decreased the protein expression of caspase-3, Bad, Bax, NF-κB, tumor necrosis factor-α, interleukin(IL)-6 and IL-1β. Furthermore, naringenin increased the expression of Bcl-xL and Bcl-2 and activated the PI3K/Akt pathway. Significant improvements in learning capacity and memory retention were observed following naringenin treatment. Naringenin effectively ameliorated cognitive dysfunction and reduced isoflurane‑induced apoptosis as well as modulating the PI3/Akt/PTEN and NF-κB signalling pathways.

Biochemical and Molecular Mechanisms of Radioprotective Effects of Naringenin, a Phytochemical from Citrus Fruits.

The present study was aimed to evaluate the radioprotective effects of naringenin in vivo using Swiss albino mice as a model system. Oral administration of 50 mg/kg body weight of naringenin for 7 days prior to radiation exposure protected mice against radiation-induced DNA, chromosomal and membrane damage. Naringenin pretreatment also increased the antioxidant status of irradiated mice. Multiple factors operating at cellular and molecular levels led to increased endogenous spleen colonies and survival of mice. Although naringenin induces apoptosis in cancer cells we found that it can protect against radiation-induced apoptosis in normal cells by modulating the expression of p53, Bax, and Bcl-2. The results from the present study indicate that naringenin inhibits the NF-kB pathway and down regulates radiation-induced apoptotic proteins resulting in radioprotection at the cellular, tissue and organism levels.

Naringenin improves learning and memory in an Alzheimer's disease rat model: Insights into the underlying mechanisms

Alzheimer's disease (AD) is one of the prevalent neurological disorders of the central nervous system hallmarked by increased beta-amyloid (Aβ) deposition and ensuing learning and memory deficit. In the present study, the beneficial effect of naringenin on improvement of learning and memory was evaluated in an Alzheimer's disease rat model. The Aβ-injected rats showed a lower alternation score in Y-maze task, impairment of retention and recall capability in passive avoidance test, and lower correct choices and higher errors in radial arm maze (RAM) task as compared to sham group in addition to enhanced oxidative stress and apoptosis. Naringenin, but not a combination of naringenin and fulvestrant (an estrogenic receptor antagonist) significantly improved the performance of Aβ-injected rats in passive avoidance and RAM tasks. Naringenin pretreatment of Aβ-injected rats also lowered hippocampal malondialdehyde (MDA) with no significant effect on nitrite and superoxide dismutase (SOD) activity in addition to lowering apoptosis. These results suggest naringenin pretreatment attenuates Aβ-induced impairment of learning and memory through mitigation of lipid peroxidation and apoptosis and its beneficial effect is somewhat mediated via estrogenic pathway.

Naringenin ameliorates Alzheimer’s disease (AD)-type neurodegeneration with cognitive impairment (AD-TNDCI) caused by the intracerebroventricular-streptozotocin in rat model

Oxidative stress is involved in Alzheimer's disease (AD)-type neurodegeneration with cognitive impairment (AD-TNDCI) as well as age related cognitive deficit. The present study was designed to investigate the pre-treatment effects of naringenin (NAR), a polyphenolic compound on cognitive dysfunction, oxidative stress in the hippocampus, and hippocampal neuron injury in a rat model of AD-TNDCI. The rats were pre-treated with NAR at a selective dose (50mg/kg, orally) for 2 weeks followed by intracerebroventricular-streptozotocin (ICV-STZ) (3mg/kg; 5μl per site) injection bilaterally. Behavioral alterations were monitored after 2 weeks from the lesion using passive avoidance test and Morris water maze paradigm. Three weeks after the lesion, the rats were sacrificed for measuring non-enzymatic [4-hydroxynonenal (4-HNE), malonaldehyde (MDA), thiobarbituric reactive substances (TBARS), hydrogen peroxide (H(2)O(2)), protein carbonyl (PC), reduced glutathione (GSH)] content and enzymatic [glutathione peroxidase (GPx), glutathione reductase (GR), glutathione-S-transferase (GST), superoxide dismutase (SOD), catalase (CAT) and Na(+)/K(+)-ATPase] activity in the hippocampus, and expression of choline acetyltransferase (ChAT) positive neuron, and histopathology of hippocampal neurons. The non-enzymatic level and enzymatic activity was significantly increased and decreased, respectively, with striking impairments in spatial learning and memory, loss of ChAT positive neuron and severe damage to hippocampal neurons in the rat induced by ICV-STZ. These abnormalities were significantly improved by NAR pre-treatment. The study suggests that NAR can protect against cognitive deficits, neuronal injury and oxidative stress induced by ICV-STZ, and may be used as a potential agent in treatment of neurodegenerative diseases such as AD-TNDCI.