Effects of intranasal oxytocin on the attentional bias to emotional stimuli in patients with bulimia nervosa

Background: Bulimia nervosa (BN) is characterized by binge eating and emotional dysregulation including increased negative affectivity (anger, anxiety). The aim of this study was to examine the effect of oxytocin on attentional processes towards anger in patients with BN. Method: The study design consisted of a double-blind, placebo-controlled within-subject crossover, single dose experiment. Sixty-four women (31 patients with BN and 33 healthy comparisons) completed self-reported measures to evaluate emotional difficulties and were administered a single dose of intranasal oxytocin (40IU) or placebo followed by a visual probe detection task to examine attentional orienting to angry or happy faces. Results: Patients with BN reported higher emotional dysregulation and more difficulties in controlling anger compared to the healthy comparison group. Patients with BN and the healthy women exhibited similar attentional bias to angry faces in the placebo condition. Intranasal oxytocin reduced the attentional bias towards angry faces in both the BN patients and the healthy women. Conclusions: We found that a single dose of oxytocin reduced vigilance towards angry faces in patients with BN as well as healthy women. The results showed that patients with BN are not different from healthy women in terms of vigilance towards threat

Effects of intranasal oxytocin on the attentional bias to emotional stimuli in patients with bulimia nervosa

Background Bulimia nervosa (BN) is characterized by binge eating and emotional dysregulation including increased negative affectivity (anger, anxiety). The aim of this study was to examine the effect of oxytocin on attentional processes towards anger in patients with BN. Method The study design consisted of a double-blind, placebo-controlled within-subject crossover, single dose experiment. Sixty-four women (31 patients with BN and 33 healthy comparisons) completed self-reported measures to evaluate emotional difficulties and were administered a single dose of intranasal oxytocin (40IU) or placebo followed by a visual probe detection task to examine attentional orienting to angry or happy faces. Results Patients with BN reported higher emotional dysregulation and more difficulties in controlling anger compared to the healthy comparison group. Patients with BN and the healthy women exhibited similar attentional bias to angry faces in the placebo condition. Intranasal oxytocin reduced the attentional bias towards angry faces in both the BN patients and the healthy women. Conclusions We found that a single dose of oxytocin reduced vigilance towards angry faces in patients with BN as well as healthy women. The results showed that patients with BN are not different from healthy women in terms of vigilance towards threat

Meta-analytic review of the effects of a single dose of intranasal oxytocin on threat processing in humans

BackgroundHeightened threat sensitivity is a transdiagnostic feature in several psychiatric disorders. The neuropeptide oxytocin has been shown to reduce fear related behaviours and facilitated fear extinction in animals. These findings have led to increasing interest to explore the effects of intranasal oxytocin on threat processing in humans.MethodsThe review included 26 studies (N = 1173), nine of which included clinical populations (N = 234). The clinical groups included were people with borderline personality disorder (BPD), anorexia nervosa, bulimia nervosa, depression, anxiety, and alcohol dependence disorder. We examined the effects of a single dose of intranasal oxytocin on startle response, attentional responses, and behavioural responses to threat.ResultsA single dose of intranasal oxytocin significantly increased the physiological startle response to threat in healthy people with a small effect size. However, oxytocin did not have significant effects on attentional bias towards social or disorder-specific threat, fixation towards threatening stimuli among healthy or clinical populations, or on threat related behavioural approach or avoidance responses.LimitationsNo studies investigated the effects of oxytocin on the startle response to threat among clinical populations. Additionally, only one of the reviewed studies had sufficient power to detect at least a moderate effect of oxytocin according to our criterion.DiscussionThe synthesis of literature suggest that oxytocin may influence the salience of threatening stimuli among healthy individuals, increasing the startle response to threat. It would be of interest to investigate the effects of oxytocin on the startle response to threat among clinical populations

Nanostructured, Self-Assembling Peptide K5 Blocks TNF-α and PGE2 Production by Suppression of the AP-1/p38 Pathway

Nanostructured, self-assembling peptides hold promise for a variety of regenerative medical applications such as 3D cell culture systems, accelerated wound healing, and nerve repair. The aim of this study was to determine whether the self-assembling peptide K5 can be applied as a carrier of anti-inflammatory drugs. First, we examined whether the K5 self-assembling peptide itself can modulate various cellular inflammatory responses. We found that peptide K5 significantly suppressed the release of tumor-necrosis-factor- (TNF-) α and prostaglandin E2 (PGE2) from RAW264.7 cells and peritoneal macrophages stimulated by lipopolysaccharide (LPS). Similarly, there was inhibition of cyclooxygenase- (COX-) 2 mRNA expression assessed by real-time PCR, indicating that the inhibition is at the transcriptional level. In agreement with this finding, peptide K5 suppressed the translocation of the transcription factors activator protein (AP-1) and c-Jun and inhibited upstream inflammatory effectors including mitogen activated protein kinase (MAPK), p38, and mitogen-activated protein kinase kinase 3/6 (MKK 3/6). Whether this peptide exerts its effects via a transmembrane or cytoplasmic receptor is not clear. However, our data strongly suggest that the nanostructured, self-assembling peptide K5 may possess significant anti-inflammatory activity via suppression of the p38/AP-1 pathway

Impaired Set-Shifting Ability in Patients with Eating Disorders, Which Is Not Moderated by Their Catechol-O-Methyltransferase Val158Met Genotype

The aim of this study was to examine the set-shifting ability in women with both anorexia nervosa (AN) and bulimia nervosa (BN) and to investigate whether it is contributed by the catechol-O-methyltransferase (COMT) Val158Met genotype. A total of 102 Korean participants-40 women with lifetime AN, 28 women with lifetime BN, and 34 healthy women of comparable age and intelligence quotient- were examined. A neuropsychological battery of tests was applied and blood samples were obtained for COMT Val158Met genotyping. Set-shifting impairments Trail Making Test (TMT, Part B) were found in patients with AN and BN, respectively. Furthermore, the eating disorders were also linked to deficits in attentional mechanisms (TMT, Part A) and motor skills (Finger Tapping Test). Finally, set-shifting and its link to eating disorders were not moderated by COMT Val158Met genotype

Highly efficient visible blue-emitting black phosphorus quantum dot: Mussel-inspired surface functionalization for bioapplications

The preparation of blue-emitting black phosphorus quantum dots (BPQDs) is based on the liquid-phase exfoliation of bulk BP. We report the synthesis of soluble BPQDs showing a strong visible blue-light emission. Highly fluorescent (photoluminescence quantum yield of ~5% with the maximum emission (λmax) at ~437 nm) and dispersible BPQDs in various organic solvents are first prepared by simple ultrasonication of BP crystals in chloroform in the ambient atmosphere. Furthermore, simple mussel-inspired surface functionalization of BPQDs with catechol-grafted poly(ethylene glycol) in basic buffer afforded water-soluble blue-emitting BPQDs showing long-term fluorescence stability, very low cytotoxicity, and excellent fluorescence live cell imaging capability. © 2017 American Chemical Society.1