Melatonin Modulates the Antioxidant Defenses and the Expression of Proinflammatory Mediators in Pancreatic Stellate Cells Subjected to Hypoxia

Pancreatic stellate cells (PSC) play a major role in the formation of fibrotic tissue in pancreatic tumors. On its side, melatonin is a putative therapeutic agent for pancreatic cancer and inflammation. In this work, the actions of melatonin on PSC subjected to hypoxia were evaluated. Reactive oxygen species (ROS) generation reduced (GSH) and oxidized (GSSG) levels of glutathione, and protein and lipid oxidation were analyzed. The phosphorylation of nuclear factor erythroid 2-related factor (Nrf2), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB), and the regulatory protein nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor-alpha (IκBα) was studied. The expression of Nrf2-regulated antioxidant enzymes, superoxide dismutase (SOD) enzymes, cyclooxygenase 2 (COX-2), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were also studied. Total antioxidant capacity (TAC) was assayed. Finally, cell viability was studied. Under hypoxia and in the presence of melatonin generation of ROS was observed. No increases in the oxidation of proteins or lipids were detected. The phosphorylation of Nrf2 and the expression of the antioxidant enzymes catalytic subunit of glutamate-cysteine ligase, catalase, NAD(P)H-quinone oxidoreductase 1, heme oxygenase-1, SOD1, and of SOD2 were augmented. The TAC was increased. Protein kinase C was involved in the effects of melatonin. Melatonin decreased the GSH/GSSG ratio at the highest concentration tested. Cell viability dropped in the presence of melatonin. Finally, melatonin diminished the phosphorylation of NF-kB and the expression of COX-2, IL-6, and TNF-α. Our results indicate that melatonin, at pharmacological concentrations, modulates the red-ox state, viability, and the expression of proinflammatory mediators in PSC subjected to hypoxia.

Is Psychological Distress Associated with Self-Perceived Health, Perceived Social Support and Physical Activity Level in Spanish Adults with Diabetes?

Depressive and anxiety symptoms are common in people with type 1 and type 2 diabetes mellitus. Physical activity and social support may prevent or reduce psychological distress in this population. This study aimed to analyse the associations between psychological distress, self-perceived health (SPH), perceived social support (PSS) and physical activity level (PAL) in adults with a diabetes mellitus diagnosis from Spain. A cross-sectional study based on data from the Spanish National Health Survey (ENSE2017) with a final sample of 1006 individuals with diabetes mellitus aged between 15 and 70 years, who completed the Adult Questionnaire. Some of the items from this survey were taken from existing questionnaires: the Goldberg General Health Questionnaire (GHQ-12) for Mental Health status and psychological distress, the Duke-UNC-11 Functional Social Support Questionnaire for PSS and the International Physical Activity Questionnaire (IPAQ) for PAL. A descriptive analysis and non-parametric statistical tests were carried out, including correlation analysis, multiple binary logistic regression and linear regression model calculations. It was found that SPH was related to PAL (p < 0.001): positive SPH prevalence was higher in the Active and Very Active groups (p < 0.05). Weak inverse correlations were found between the GHQ-12 and the PAL (rho: -0.230; p < 0.001) and PSS (rho: -0.234; p < 0.001). Physical inactivity and lower PSS were risk factors for negative SPH and worst physiological outcomes. Thus, higher PAL and PSS were positively correlated with SPH and lower psychological stress in Spanish adults with diabetes mellitus.