Development and construction of the Multidimensional Self-Efficacy Scale for Epilepsy (MSESE) and its psychometric properties.

PURPOSE: It has become evident that patients with epilepsy require strong self-efficacy support in various domains, including work, social interaction, and academic performance, to ensure their complete social functioning. Nevertheless, previous studies have predominantly assessed the self-efficacy of individuals with epilepsy from a singular perspective of disease management. This study aimed to develop the Multidimensional Self-Efficacy Scale for Epilepsy (MSESE) to assess multiple dimensions and establish its psychometric properties. METHODS: We compiled a total of 25 questions for the initial version of the questionnaire based on a review of the literature and insights from experts, patients, and family members. The study included 180 adult patients with epilepsy who met the research criteria, with 126 of them serving as pre-test samples. All participants completed the MSESE, Brief Symptom Rating Scale-50 (BSRS-50), Rosenberg Self-Esteem Scale-Chinese version (RSES-C), and General Self-Efficacy Scale (GSES). RESULTS: The final scale consisted of 12 items across four dimensions, with item factor loadings ranging from .51 to .90. Most of the fit indices indicated a good fit. Construct validity was established through significant correlations with the BSRS-50, RSES-C, and GSES (r = -0.51 to 0.69, p < 0.01). Internal consistency coefficients for the MSESE were strong at .90, with individual dimensions ranging from 0.71 to 0.89. The MSESE also demonstrated a satisfactory test-retest reliability of 0.72. CONCLUSIONS: The MSESE is a convenient, multidimensional, and easy-to-use scale with good psychometric properties, making it suitable for both clinical assessments and research purposes.

The effect of facial expression intensity on emotion recognition and psychosocial performance in patients with frontal or temporal lobe epilepsy.

PURPOSE: No studies have examined the relationship between the intensity of facial emotion expression and theory of mind (ToM) ability in people with epilepsy. This study aimed to explore facial emotion recognition in a group of patients with frontal (FLE) or temporal lobe epilepsy (TLE) and its relationship with the intensities of perceived facial emotion expressions, ToM, and social functioning. METHODS: Twenty-six patients with FLE or TLE and 30 matched controls were included in the study. All participants completed the facial emotion recognition test, Faux Pas Recognition (FPR) test measuring advanced ToM, Symptom Checklist-90-Revised, Social and Occupational Functioning Scale for Epilepsy (SOFSE), and background neuropsychological tests. RESULTS: The patient group was significantly worse than the control group in recognizing facial expressions of negative emotions, particularly for medium-intensity facial expression of fear. There was no significant difference between the groups in recognizing high-intensity fear facial expressions. The scores of FPR (overall and affective ToMs) in the patient group were significantly lower than those in the control group. Additionally, the facial emotion recognition was significantly associated with the total score of FPR, and the FPR total score remarkably correlated with the Communication subscale score of the SOFSE. CONCLUSIONS: Patients with FLE or TLE had impaired ability to recognize medium-intensity facial expressions of fear. Moreover, patients' ToM deficit significantly correlated not only with their emotion recognition problem but also with their social-communicative competence. Nevertheless, we also found that increasing the intensity of expression can improve the accuracy of emotion recognition in patients with epilepsy. These findings may provide considerations for further longitudinal studies and interventions on the social difficulties of people with epilepsy.

Betel Quid Dependence Effects on Working Memory and Remote Memory in Chewers with Concurrent Use of Cigarette and Alcohol.

OBJECTIVE: The current study asked whether BQ dependence level could affect working memory (WM) and remote memory for the chewers with concurrent use of cigarettes and alcohol, a common phenomenon in Taiwan. METHODS: The standardized neuropsychological tests (Wechsler Memory Scale III (WMS-III) and Remote Memory Test) were adopted to address the BQ chewers' verbal WM, spatial WM and remote memory. The Spatial Span Test and the Digit Span Test from WMS-III and the Remote Memory Test were adopted. The Betel Nut Dependency Scale (BNDS), the Fagerstrom Test for Nicotine Dependence (FTND), and the Alcohol Use Disorders Identification Test (AUDIT) were adopted to measure the dependence levels. RESULTS: The BQ dependence level and Last BQ did not affect spatial WM, verbal WM, and remote memory. Last Cigarette is critical in affecting WM; namely, longer interval led to worse performance. Finally, higher alcohol dependence level could lead to better remote memory. CONCLUSIONS: To our knowledge, there are no BQ studies addressing the effects of concurrent use of cigarettes and alcohol on memory. The current results suggest that cigarette smoking and alcohol drinking, rather than BQ chewing, are critical for memory performance.

Treatment effects of the combination of ceftriaxone and valproic acid on neuronal and behavioural functions in a rat model of epilepsy.

NEW FINDINGS: What is the central question of this study? Imbalance of activities between GABAergic and glutamatergic systems is involved in epilepsy. It is not known whether simultaneously increasing GABAergic and decreasing glutamatergic activity using valproic acid and ceftriaxone, respectively, leads to better seizure control. What is the central question of this study? Ceftriaxone suppressed seizure and cognitive deficits and restored neuronal density and the number of newborn cells in the hippocampus in a rat model of epilepsy. Combined treatment with ceftriaxone and valproic acid showed additive effects in seizure suppression. ABSTRACT: The pathophysiology of epilepsy is typically considered as an imbalance between inhibitory GABA and excitatory glutamate neurotransmission. Valproic acid (Val), a GABA agonist, is one of the first-line antiepileptic drugs in the treatment of epilepsy, but it exhibits adverse effects. Ceftriaxone (CEF) elevates expression of glutamate transporter-1, enhances the reuptake of synaptic glutamate, increases the number of newborn cells and exhibits neuroprotective effects in animal studies. In this study, we evaluated effects of the combination of CEF and Val on behavioural and neuronal measures in a rat epilepsy model. Male Wistar rats were injected i.p. with pentylenetetrazol (35 mg/kg, every other day for 13 days) to induce the epilepsy model. Ceftriaxone (10 or 50 mg/kg), Val (50 or 100 mg/kg) or the combination of CEF and Val were injected daily after the fourth pentylenetetrazol injection for seven consecutive days. Epileptic rats exhibited seizure and impairments in motor and cognitive functions. Treatment with CEF and Val reduced the seizure and enhanced motor and cognitive functions in a dose-dependent manner. The combination of CEF (10 mg/kg) and Val (50 mg/kg) improved behaviours considerably. Histologically, compared with control animals, epileptic rats exhibited lower neuronal density and a reduction in hippocampal newborn cells but higher apoptosis in the basolateral amygdala, all of which were restored by the treatment with CEF, Val or the combination of CEF and Val. The study findings demonstrated that the combination of low doses of CEF and Val has beneficial effects on seizure suppression, neuroprotection and improvement in motor and cognitive functions in epilepsy.

Social functioning and health-related quality of life trajectories in people with epilepsy after epilepsy surgery.

OBJECTIVE: An improvement in quality of life (QoL) over time after epilepsy surgery has been demonstrated in people with epilepsy; however, social functioning has been less investigated. We conducted this study to examine whether postsurgical improvement is parallel between QoL and social functioning in patients with epilepsy. METHODS: We retrospectively reviewed patients who underwent epilepsy surgery. All participants completed a comprehensive neuropsychological assessment, the Quality of Life in Epilepsy Inventory (QOLIE-89) questionnaire, and the Social and Occupational Functioning Scale for Epilepsy (SOFSE) before surgery and at 3 months, 6 months, and 1 year after surgery. Demographic and epilepsy-related information was also collected. Generalized estimating equations with identity links were used to model the QOLIE-89 and SOFSE over time and possible associated factors. A p < 0.05 was considered statistically significant. RESULTS: A total of 76 patients, including 36 males and 43 females aged 18 to 62 years were collected. Both total QOLIE-89 and overall SOFSE improved over time after epilepsy surgery (adjusted p value < 0.001 and 0.002, respectively, with Bonferroni's correction). Total QOLIE-89 improved 3 months after surgery, while overall SOFSE showed no significant improvement until 6 months after surgery. The presurgical Full-Scale Intelligence Quotient (FSIQ) of the Wechsler Adult Intelligence Scale-III and years of education were significantly associated with time-dependent improvement for both total QOLIE-89 and overall SOFSE (p value < 0.001). At one year after surgery, overall SOFSE and total QOLIE-89 scores were significantly higher in the seizure-free group than in the nonseizure-free group (p value = 0.040 and 0.032, respectively). CONCLUSION: Social functioning significantly improved in people with epilepsy after surgery as QoL, but it took more time to exhibit improvement. People with better FSIQ and more years of education had better improvement in social functioning over time. The early intervention of rehabilitation programs after epilepsy surgery might be necessary to facilitate the improvement in social functioning.

O-GlcNAc Site Mapping by Using a Combination of Chemoenzymatic Labeling, Copper-Free Click Chemistry, Reductive Cleavage, and Electron-Transfer Dissociation Mass Spectrometry.

As a dynamic post-translational modification, O-linked ß- N-acetylglucosamine ( O-GlcNAc) modification (i.e., O-GlcNAcylation) of proteins regulates many biological processes involving cellular metabolism and signaling. However, O-GlcNAc site mapping, a prerequisite for site-specific functional characterization, has been a challenge since its discovery. Herein we present a novel method for O-GlcNAc enrichment and site mapping. In this method, the O-GlcNAc moiety on peptides was labeled with UDP-GalNAz followed by copper-free azide-alkyne cycloaddition with a multifunctional reagent bearing a terminal cyclooctyne, a disulfide bridge, and a biotin handle. The tagged peptides were then released from NeutrAvidin beads upon reductant treatment, alkylated with (3-acrylamidopropyl)trimethylammonium chloride, and subjected to electron-transfer dissociation mass spectrometry analysis. After validation by using standard synthetic peptide gCTD and model protein α-crystallin, such an approach was applied to the site mapping of overexpressed TGF-ß-activated kinase 1/MAP3K7 binding protein 2 (TAB2), with four O-GlcNAc sites unambiguously identified. Our method provides a promising tool for the site-specific characterization of O-GlcNAcylation of important proteins.

Unambiguous Sequence Characterization of a Monoclonal Antibody in a Single Analysis Using a Nonspecific Immobilized Enzyme Reactor.

Accurate sequence characterization is essential for the development of therapeutic antibodies by the pharmaceutical industry. Presented here is a methodology to obtain comprehensive sequence analysis of a monoclonal antibody. An enzyme reactor of immobilized Aspergillopepsin I, a highly stable nonspecific protease, was used to cleave reduced antibody subunits into a peptide profile ranging from 1 to 20 kDa. Utilizing the Thermo Orbitrap Fusion's unique instrument architecture combined with state-of-the-art instrument control software allowed for dynamic instrument methods that optimally characterize eluting peptides based on their size and charge density. Using a data-dependent instrument method, both collisional dissociation and electron transfer dissociation were used to fragment the appropriate charge state of analyte peptides. The instrument layout also allowed for scans to be taken in parallel using both the ion trap and Orbitrap concurrently, thus allowing larger peptides to be analyzed in high resolution using the Orbitrap while simultaneously analyzing tryptic-like peptides using the ion trap. We harnessed these capabilities to develop a custom method to optimally fragment the eluting peptides based on their mass and charge density. Using this approach, we obtained 100% sequence coverage of the total antibody in a single chromatographic analysis, enabling unambiguous sequence assignment of all residues.

Analysis of Monoclonal Antibody Sequence and Post-translational Modifications by Time-controlled Proteolysis and Tandem Mass Spectrometry.

Methodology for sequence analysis of ∼150 kDa monoclonal antibodies (mAb), including location of post-translational modifications and disulfide bonds, is described. Limited digestion of fully denatured (reduced and alkylated) antibody was accomplished in seconds by flowing a sample in 8murea at a controlled flow rate through a micro column reactor containing immobilized aspergillopepsin I. The resulting product mixture containing 3-9 kDa peptides was then fractionated by capillary column liquid chromatography and analyzed on-line by both electron-transfer dissociation and collisionally activated dissociation mass spectrometry (MS). This approach enabled identification of peptides that cover the complete sequence of a murine mAb. With customized tandem MS and ProSightPC Biomarker search, we verified 95% amino acid residues of this mAb and identified numerous post-translational modifications (oxidized methionine, pyroglutamylation, deamidation of Asn, and several forms ofN-linked glycosylation). For disulfide bond location, native mAb is subjected to the same procedure but with longer digestion times controlled by sample flow rate through the micro column reactor. Release of disulfide containing peptides from accessible regions of the folded antibody occurs with short digestion times. Release of those in the interior of the molecule requires longer digestion times. The identity of two peptides connected by a disulfide bond is determined using a combination of electron-transfer dissociation and ion-ion proton transfer chemistry to read the two N-terminal and two C-terminal sequences of the connected peptides.

Pepsin-Containing Membranes for Controlled Monoclonal Antibody Digestion Prior to Mass Spectrometry Analysis.

Monoclonal antibodies (mAbs) are the fastest growing class of therapeutic drugs, because of their high specificities to target cells. Facile analysis of therapeutic mAbs and their post-translational modifications (PTMs) is essential for quality control, and mass spectrometry (MS) is the most powerful tool for antibody characterization. This study uses pepsin-containing nylon membranes as controlled proteolysis reactors for mAb digestion prior to ultrahigh-resolution Orbitrap MS analysis. Variation of the residence times (from 3 ms to 3 s) of antibody solutions in the membranes yields "bottom-up" (1-2 kDa) to "middle-down" (5-15 kDa) peptide sizes within less than 10 min. These peptides cover the entire sequences of Trastuzumab and a Waters antibody, and a proteolytic peptide comprised of 140 amino acids from the Waters antibody contains all three complementarity determining regions on the light chain. This work compares the performance of "bottom-up" (in-solution tryptic digestion), "top-down" (intact protein fragmentation), and "middle-down" (in-membrane digestion) analysis of an antibody light chain. Data from tandem MS show 99%, 55%, and 99% bond cleavage for "bottom-up", "top-down", and "middle-down" analyses, respectively. In-membrane digestion also facilitates detection of PTMs such as oxidation, deamidation, N-terminal pyroglutamic acid formation, and glycosylation. Compared to "bottom-up" and "top-down" approaches for antibody characterization, in-membrane digestion uses minimal sample preparation time, and this technique also yields high peptide and sequence coverage for the identification of PTMs.

Site-Specific Zwitterionic Polymer Conjugates of a Protein Have Long Plasma Circulation.

Many proteins suffer from suboptimal pharmacokinetics (PK) that limit their utility as drugs. The efficient synthesis of polymer conjugates of protein drugs with tunable PK to optimize their in vivo efficacy is hence critical. We report here the first study of the in vivo behavior of a site-specific conjugate of a zwitterionic polymer and a protein. To synthesize the conjugate, we first installed an initiator for atom-transfer radical polymerization (ATRP) at the N terminus of myoglobin (Mb-N-Br). Subsequently, in situ ATRP was carried out in aqueous buffer to grow an amine-functionalized polymer from Mb-N-Br. The cationic polymer was further derivatized to two zwitterionic polymers by treating the amine groups of the cationic polymer with iodoacetic acid to obtain poly(carboxybetaine methacrylate) with a one-carbon spacer (PCBMA; C1 ), and sequentially with 3-iodopropionic acid and iodoacetic acid to obtain PCBMA(mix) with a mixture of C1 and C2 spacers. The Mb-N-PCBMA polymer conjugates had a longer in vivo plasma half-life than a PEG-like comb polymer conjugate of similar molecular weights (MW). The structure of the zwitterion plays a role in controlling the in vivo behavior of the conjugate, as the PCBMA conjugate with a C1 spacer had significantly longer plasma circulation than the conjugate with a mixture of C1 and C2 spacers.

Theory of mind and social functioning in patients with temporal lobe epilepsy.

OBJECTIVE: This study aimed to explore the effects of theory of mind (ToM) and related potential risk factors, including cognitive functions, psychiatric status, and seizure-related clinical variables, on social functioning in patients with temporal lobe epilepsy (TLE). METHODS: Sixty-seven patients with intractable TLE who were potential candidates for epilepsy surgery and 30 matched controls were included. All participants completed four tasks measuring different levels of ToM (False Belief, Faux Pas Recognition, Implication Stories, and Visual Cartoon), the Symptom Checklist-90-Revised (SCL-90-R), the Social and Occupational Functioning Scale for Epilepsy (SOFSE), and neuropsychological tests. RESULTS: The patients exhibited impairments in both basic and advanced ToM. Multiple regression analyses revealed the following: (1) the SOFSE total score was significantly predicted by the Faux Pas Recognition (FPR), Global Severity Index (GSI) score of the SCL-90-R, and Full-Scale intelligence quotient (IQ) of the Wechsler Adult Intelligence Scale (WAIS), which accounted for 38%, 11%, and 8% of the variance, respectively; and (2) the FPR was a significant predictor of all SOFSE subscales, whereas the GSI score contributed substantially to the Interpersonal Relationships, Communication, and Occupation subscales of the SOFSE. SIGNIFICANCE: Advanced ToM, measured by impaired faux pas recognition, is a relatively strong predictor of poor social functioning in surgical candidates for intractable TLE. Identifying ToM impairment may help plan nonpharmacologic treatment for improving social functions in patients with intractable TLE.

Phosphopeptide enrichment with TiO2-modified membranes and investigation of tau protein phosphorylation.

Selective enrichment of phosphopeptides prior to their analysis by mass spectrometry (MS) is vital for identifying protein phosphorylation sites involved in cellular regulation. This study describes modification of porous nylon substrates with TiO2 nanoparticles to create membranes that rapidly enrich phosphopeptides. Membranes with a 22-mm diameter bind 540 nmol of phosphoangiotensin and recover 70% of the phosphopeptides in mixtures with a 15-fold excess of nonphosphorylated proteins. Recovery is 90% for a pure phosphopeptide. Insertion of small membrane disks into HPLC fittings allows rapid enrichment from 5 mL of 1 fmol/µL phosphoprotein digests and concentration into small-volume (tens of microliters) eluates. The combination of membrane enrichment with tandem mass spectrometry reveals seven phosphorylation sites from in vivo phosphorylated tau (p-tau) protein, which is associated with Alzheimer's disease.

The Social and Occupational Functioning Scale for Epilepsy (SOFSE): a brief measure of functional status in a Taiwanese sample with epilepsy.

PURPOSE: To develop and validate a scale of social functioning for people with epilepsy (PWE)-the Social and Occupational Functioning Scale for Epilepsy (SOFSE). METHODS: According to the literature review and opinions from a panel of experts, PWE, and caregivers, a total of 31 questions were compiled. Questionnaires were analyzed from 172 adults with epilepsy. KEY FINDINGS: The final scale had 30 items in six dimensions. The results showed that internal consistency coefficients and test-retest reliabilities for each dimension ranged from 0.70 to 0.84 and 0.72 to 0.89, respectively. Retest reliability for the total SOFSE score was 0.92. Seven factors were extracted through principal factor analysis. Moreover, criterion-related validity was demonstrated by the significant correlations between the SOFSE and the following measures: the Mini Mental Status Examination (r = 0.60, p < 0.001), the Quality of Life in Epilepsy-31 (r = 0.53, p < 0.001), and the Global Severity Index of the Symptom Checklist-90-Revised (r = -0.66, p < 0.001). Finally, the differences in functional competence among patients also supported the discriminant validity of the inventory. SIGNIFICANCE: The SOFSE is a brief, psychometrically sound, and easy-to-administer measure of social functioning for use in busy clinical settings.

Ni-Catalyzed Asymmetric C-P Cross-Coupling Reaction for the Synthesis of Chiral Heterocyclic Phosphine Oxides.

Nickel performs excellently in C-C and C-X cross-coupling reactions. Here, we disclose a Ni(II)-catalyzed asymmetric C-P cross-coupling reaction to afford valuable chiral heterocyclic tertiary phosphine oxides. The method is mild and efficient, which invokes a self-sustained nickel catalytic cycle without an external reductant, light irradiation, or electricity.

Limited proteolysis via millisecond digestions in protease-modified membranes.

Sequential adsorption of poly(styrene sulfonate) (PSS) and proteases in porous nylon yields enzymatic membrane reactors for limited protein digestion. Although a high local enzyme density (~30 mg/cm(3)) and small pore diameters in the membrane lead to digestion in <1 s, the low membrane thickness (170 µm) affords control over residence times at the millisecond level to limit digestion. Apomyoglobin digestion demonstrates that peptide lengths increase as the residence time in the membrane decreases. Moreover, electron transfer dissociation (ETD) tandem mass spectrometry (MS/MS) on a large myoglobin proteolytic peptide (8 kDa) provides a resolution of 1-2 amino acids. Under denaturing conditions, limited membrane digestion of bovine serum albumin (BSA) and subsequent ESI-Orbitrap MS analysis reveal large peptides (3-10 kDa) that increase the sequence coverage from 53% (2 s digestion) to 82% (0.05 s digestion). With this approach, we also performed membrane-based limited proteolysis of a large Arabidopsis GTPase, Root Hair Defective 3 (RHD3) and showed suitable probing for labile regions near the C-terminus to suggest what protein reconstruction might make RHD3 more suitable for crystallization.

Bifunctional polymer brushes for low-bias enrichment of mono- and multi-phosphorylated peptides prior to mass spectrometry analysis.

Polymer brushes orthogonally derivatized with oxotitanium and nitrilotriacetate-Fe(III) groups enrich both mono- and multi-phosphorylated peptides for mass spectrometry analysis.

Neuropsychological performance and seizure-related risk factors in patients with temporal lobe epilepsy: a retrospective cross-sectional study.

The aim of this study was to identify the neuropsychological features in patients with temporal lobe epilepsy (TLE) and their correlation with seizure-related variables. For this purpose, we carried out a retrospective analysis of data from 65 patients with TLE who had undergone a comprehensive neuropsychological assessment. The results suggest that the majority of patients with TLE were impaired in more than one cognitive domain, and among these patients, the mean proportions with defective semantic memory, language, motor/psychomotor speed, verbal episodic memory, and executive function were >50% each. Moreover, age at seizure onset was the strongest predictor of general intellectual impairment, and number of antiepileptic drugs and seizure frequency could significantly predict deficits in verbal memory, language, and psychomotor speed. However, epilepsy duration was a less potent predictor of cognitive deficit than has been reported in cross-sectional studies.

Cerebroprotection by dioscin after experimental subarachnoid haemorrhage via inhibiting NLRP3 inflammasome through SIRT1-dependent pathway.

BACKGROUND AND PURPOSE: Dioscin has multiple biological activities and is beneficial for cardiovascular and cerebral vascular diseases. Here, we investigated the protective effects of dioscin against subarachnoid haemorrhage and the molecular mechanisms involved. EXPERIMENTAL APPROACH: Dioscin was administered after subarachnoid haemorrhage induced in rats. MCC950, a potent selective nod-like receptor pyrin domain-containing 3 (NLRP3) inhibitor, was used to suppress NLRP3 and EX527 (selisistat) was used to inhibit sirtuin 1 (SIRT1). KEY RESULTS: In vivo, dioscin inhibited acute inflammatory response, oxidative damage, neurological impairment and neural cell degeneration after subarachnoid haemorrhage along with dramatically suppressing NLRP3 inflammasome activation. While pretreatment with MCC950 reduced the inflammatory response and improved neurological outcomes it did not lessen ROS production. However, giving dioscin after MCC950 reduced acute brain damage and ROS production. Dioscin increased SIRT1 expression after subarachnoid haemorrhage, whereas EX527 abolished the up-regulation of SIRT1 induced by dioscin and offset the inhibitory effects of dioscin on NLRP3 inflammasome activation. EX527 pretreatment also reversed the neuroprotective effects of dioscin against subarachnoid haemorrhage. Similarly, in vitro, dioscin dose-dependently suppressed inflammatory response, oxidative damage and neuronal degeneration and improved cell viability in neurons and microglia co-culture system. These effects were associated with inhibition of the NLRP3 inflammasome and stimulation of SIRT1 signalling, which could be inhibited by EX527 pretreatment. CONCLUSION AND IMPLICATIONS: Dioscin provides protection against subarachnoid haemorrhage via the suppression of NLRP3 inflammasome activation through SIRT1-dependent pathway. Dioscin may be a new candidate to ameliorate early brain injury after subarachnoid haemorrhage.

Astaxanthin ameliorates oxidative stress and neuronal apoptosis via SIRT1/NRF2/Prx2/ASK1/p38 after traumatic brain injury in mice.

BACKGROUND AND PURPOSE: Oxidative stress and neuronal apoptosis play key roles in traumatic brain injury. We investigated the protective effects of astaxanthin against traumatic brain injury and its underlying mechanisms of action. EXPERIMENTAL APPROACH: A weight-drop model of traumatic brain injury in vivo and hydrogen peroxide exposure in vitro model were established. Brain oedema, behaviour tests, western blot, biochemical analysis, lesion volume, histopathological study and cell viability were performed. KEY RESULTS: Astaxanthin significantly reduced oxidative insults on Days 1, 3 and 7 after traumatic brain injury. Neuronal apoptosis was also ameliorated on Day 3. Additionally, astaxanthin improved neurological functions up to 3 weeks after traumatic brain injury. Astaxanthin treatment dramatically enhanced the expression of peroxiredoxin 2 (Prx2), nuclear factor-erythroid 2-related factor 2 (NRF2/Nrf2) and sirtuin 1 (SIRT1), while it down-regulated the phosphorylation of apoptosis signal-regulating kinase 1 (ASK1) and p38. Inhibition of Prx2 by siRNA injection reversed the beneficial effects of astaxanthin against traumatic brain injury. Additionally, Nrf2 knockout prevented the neuroprotective effects of astaxanthin in traumatic brain injury. In contrast, overexpression of Prx2 in Nrf2 knockout mice attenuated the secondary brain injury after traumatic brain injury. Moreover, inhibiting SIRT1 by EX527 dramatically inhibited the neuroprotective effects of astaxanthin and suppressed SIRT1/Nrf2/Prx2/ASK1/p38 pathway both in vivo and in vitro. CONCLUSION AND IMPLICATIONS: Astaxanthin improved the neurological functions and protected the brain from injury after traumatic brain injury, primarily by reducing oxidative stress and neuronal death via SIRT1/Nrf2/Prx2/ASK1/p38 signalling pathway and might be a new candidate to ameliorate traumatic brain injury.