The predictive role of proinflammatory and neuroendocrine factors in the acute phases of bipolar disorder: study protocol of a longitudinal controlled trial.

INTRODUCTION AND AIMS: Bipolar disorder (BD) is a severe and recurring mental illness associated with a significant personal and social burden. It has been recently hypothesized that increased levels of pro-inflammatory cytokines and cortisol, which is also associated with a reduced expression of the brain-derived neurotrophic factor (BDNF), may influence affective recurrences in BD. Our study aims to: 1) assess changes in the levels of peripheral cytokines, BDNF and salivary cortisol during acute and euthymic phases of bipolar disorder, compared to that of a sample oh healthy controls; 2) evaluate whether these changes represent a biosignature for the different phases of the illness. MATERIALS AND METHODS: Patients aged 18-65 years old, with a diagnosis of BD I or II types, will be enrolled during an acute episode, according to DSM-5 criteria, together with age- and gender-matched healthy controls. Blood and salivary samples will be collected at baseline and after 3 and 6 months. Validated assessment instruments will be administered to all participants for the evaluation of symptom severity, global functioning, suicidal risk, stress levels and physical comorbidities. EXPECTED RESULTS: We expect changes in inflammatory and neuroendocrine indices to be predictive of the onset of an acute phase of bipolar disorder and that overall levels of cytokines, cortisol and BDNF are overall significantly different between BD patients and healthy controls. CONCLUSIONS: The longitudinal design of the study will allow to assess whether the presence of acute affective symptoms in BD patients correlates with significantly higher levels of cytokines and salivary cortisol and with reduced BDNF levels compared to euthymic phases. Moreover, the comparison with healthy control subjects will allow to understand if inflammatory mediators as well as the hypothalamic-pituitary-adrenal (HPA) axis are chronically elevated in BD patients and are independent from mood swings.

Rosmarinic Acid Improves Cognitive Abilities and Glucose Metabolism in Aged C57Bl/6N Mice While Disrupting Lipid Profile in Young Adults in a Sex-Dependent Fashion.

A growing body of evidence suggests that regular consumption of natural products might promote healthy aging; however, their mechanisms of action are still unclear. Rosmarinic acid (RA) is a polyphenol holding anti-inflammatory, antioxidant and neuroprotective properties. The aim of this study was to characterise the efficacy of an oral administration of RA in promoting healthspan in a mouse model of physiological aging. Aged C57Bl/6 male and female (24-month-old) mice were either administered with RA (500 mg/Kg) or a vehicle in drinking bottles for 52 days while 3-month-old mice receiving the same treatment were used as controls. All subjects were assessed for cognitive abilities in the Morris water maze (MWM) and for emotionality in the elevated-plus maze test (EPM). Brain-derived Neurotrophic Factor (BDNF) protein levels were evaluated in the hippocampus. Since the interaction between metabolic signals and cerebral functions plays a pivotal role in the etiopathogenesis of cognitive decline, the glycaemic and lipid profiles of the mice were also assessed. RA enhanced learning and memory in 24-month-old mice, an effect that was associated to improved glucose homeostasis. By contrast, the lipid profile was disrupted in young adults. This effect was associated with worse glycaemic control in males and with reduced BDNF levels in females, suggesting powerful sex-dependent effects and raising a note of caution for RA administration in young healthy adult subjects.