New Therapeutic Approaches against Inflammation and Oxidative Stress in Neurodegeneration

Dietary acid load as well as dietary phytochemical index, and association with multiple sclerosis: results from a case-control study

INTRODUCTION

Multiple sclerosis (MS) is a chronic inflammatory disease characterized by central nervous system (CNS) lesions. Although the etiology and pathogenesis of MS remains unclear, nutrition is among the environmental factors that may be involved in developing MS. Currently, no specific diet has been associated with MS. This study aimed to investigate the relationship between the dietary phytochemical index (DPI), dietary acid load (DAL), and the risk of developing MS.

METHODS

This case‒control study was conducted on 174 patients with MS and 171 healthy individuals in Mashhad, Iran. Data were collected using a 160-item semiquantitative food frequency questionnaire (FFQ). The study investigated the association between DPI, DAL, and MS, considering anthropometric measures, dietary intake, smoking habits, and sex. DPI, potential renal acid load (PRAL), and net endogenous acid production (NEAP), as indicators of DAL, were calculated based on the FFQ.

RESULTS

The study analyzed 345 participants, comprising 174 (50.4%) MS patients and 171 (49.6%) healthy individuals. The mean age of the participants was 32.45 ± 8.66 years. The DPI score was significantly lower among MS patients, while the NEAP and PRAL scores were significantly higher among MS patients compared to the healthy group. There was no relationship between NEAP (OR 1.001; 95% CI 0.959-1.044; P = 0.974) and PRAL (OR 1.019; 95% CI 0.979-1.061; P = 0.356) and MS incidence.

CONCLUSIONS

The study found higher smoking and obesity rates in MS patients, with a reduced DPI score and increased DAL. Further studies are needed before recommending plant-based foods and dietary acid-base balance evaluation as therapeutic approach.

The dangerous "West Coast Swing" by hyperglycaemia and chronic stress in the mouse hippocampus: Role of kynurenine catabolism

Growing epidemiological studies highlight a bi-directional relationship between depressive symptoms and diabetes mellitus. However, the detrimental impact of their co-existence on mental health suggests the need to treat this comorbidity as a separate entity rather than the two different pathologies. Herein, we characterized the peculiar mechanisms activated in mouse hippocampus from the concurrent development of hyperglycaemia, characterizing the different diabetes subtypes, and chronic stress, recognized as a possible factor predisposing to major depression. Our work demonstrates that kynurenine overproduction, leading to apoptosis in the hippocampus, is triggered in a different way depending on hyperglycaemia or chronic stress. Indeed, in the former, kynurenine appears produced by infiltered macrophages whereas, in the latter, peripheral kynurenine preferentially promotes resident microglia activation. In this scenario, QA, derived from kynurenine catabolism, appears a key mediator causing glutamatergic synapse dysfunction and apoptosis, thus contributing to brain atrophy. We demonstrated that the coexistence of hyperglycaemia and chronic stress worsened hippocampal damage through alternative mechanisms, such as GLUT-4 and BDNF down-expression, denoting mitochondrial dysfunction and apoptosis on one hand and evoking the compromission of neurogenesis on the other. Overall, in the degeneration of neurovascular unit, hyperglycaemia and chronic stress interacted each other as the partners of a "West Coast Swing" in which the leading role can be assumed alternatively by each partner of the dance. The comprehension of these mechanisms can open novel perspectives in the management of diabetic/depressed patients, but also in the understanding the pathogenesis of other neurodegenerative disease characterized by the compromission of hippocampal function.