Age-related changes in melatonin synthesis in rat extrapineal tissues

7 páginas, 5 figuras, 1 tabla.In the search of new therapeutic targets improving the quality of life of elderly, melatonin, “the chemical expression of darkness”, seems to play a remarkable role in aging process possibly due to its antioxidant, immunoenhancer and anti-aging properties. The present study was designed to elucidate effects of aging in melatonin extrapineal synthesis and investigate evident age-related alterations in the action mechanisms involved. The presence of the two key enzymes involved in melatonin synthesis, arylalkylamine-N-acetyltransferase (AA-NAT) and hydroxyindole-O-methyltransferase (HIOMT) was analyzed in thymus, spleen, liver, kidney and heart of 3- and 12 month-old rats using real time PCR as well as its functionality by enzymatic activity assays. In addition, extrapineal melatonin content was measured by a competitive enzyme immunoassay (ELISA). The results of this study reveal that all rat tissues studied including thymus, and for the first time, spleen, liver, kidney and heart have the necessary machinery to synthesize melatonin. Moreover, we report an age-related decline in rat extrapineal melatonin synthesis with a consequent HIOMT functionality decrease in spleen, liver and heart during physiological aging. On the contrary, NAT enzymatic activity maintains unchanged without evident alterations with advancing age. Moreover, diminished melatonin concentrations were measured in these tissues cited above during aging except in the thymus, where, surprisingly, melatonin content, NAT/HIOMT expression, and enzymatic functionality assays revealed no significant alterations with age. As a conclusion, we report evident age-related changes in melatonin synthesis in some rat peripheral organs. We suggest that thymus may develop compensatory mechanisms to counteract the loss of immune activity and consequently, the loss of this potent antioxidant, during physiological aging.This work was supported by grants of the Andalucía (P06-CTS-1604) and Spanish (PI 060091; RD06/00130001) governments. MSH gratefully acknowledges support from a Postgraduate National Program of FPU fellowship and financial sponsorship from the Spanish MEC.Peer reviewe

Olive oil and health: Summary of the II international conference on olive oil and health consensus report, Jaén and Córdoba (Spain) 2008

Olive oil (OO) is the most representative food of the traditional Mediterranean Diet (MedDiet). Increasing evidence suggests that monounsaturated fatty acids (MUFA) as a nutrient, OO as a food, and the MedDiet as a food pattern are associated with a decreased risk of cardiovascular disease, obesity, metabolic syndrome, type 2 diabetes and hypertension. A MedDiet rich in OO and OO per se has been shown to improve cardiovascular risk factors, such as lipid profiles, blood pressure, postprandial hyperlipidemia, endothelial dysfunction, oxidative stress, and antithrombotic profiles. Some of these beneficial effects can be attributed to the OO minor components. Therefore, the definition of the MedDiet should include OO. Phenolic compounds in OO have shown antioxidant and anti-inflammatory properties, prevent lipoperoxidation, induce favorable changes of lipid profile, improve endothelial function, and disclose antithrombotic properties. Observational studies from Mediterranean cohorts have suggested that dietary MUFA may be protective against age-related cognitive decline and Alzheimer's disease. Recent studies consistently support the concept that the OO-rich MedDiet is compatible with healthier aging and increased longevity. In countries where the population adheres to the MedDiet, such as Spain, Greece and Italy, and OO is the principal source of fat, rates of cancer incidence are lower than in northern European countries. Experimental and human cellular studies have provided new evidence on the potential protective effect of OO on cancer. Furthermore, results of case-control and cohort studies suggest that MUFA intake including OO is associated with a reduction in cancer risk (mainly breast, colorectal and prostate cancers).CIBEROBN is an initiative of ISCIII and CEAS Foundation, Spain.Peer reviewe