Strategies to Improve the Functions and Redox State of the Immune System in Aged Subjects

Abstract

The aging process is accompanied by an impairment of the physiological systems including the immune system. This system is an excellent indicator of health. We have also observed that several functions of the immune cells are good markers of biological age and predictors of longevity. In agreement with the oxidation-inflammation theory that we have proposed, the chronic oxidative stress that appears with age affects all cells and especially those of the regulatory systems, such as the nervous, endocrine and immune systems and the communication between them. This fact prevents an adequate homeostasis and, therefore, the preservation of health. We have also proposed an involvement of the immune system in the aging process of the organism, concretely in the rate of aging, since there is a relation between the redox state and functional capacity of the immune cells and the longevity of individuals. A confirmation of the central role of the immune system in oxi-inflamm-aging is that several lifestyle strategies such as the administration of adequate amounts of antioxidants in the diet, physical exercise, physical and mental activity through environmental enrichment and hormetic interventions improve functions of immune cells, decreasing their oxidative stress, and consequently increasing the longevity of individuals. Recent results in mice of investigations on the effects of a new environmental enrichment (bathing in waters) as well as a hormetic intervention with slight infections (caused by injection of E.coli lipopolysaccharide, LPS), on several functions and redox parameters are shown. The advantages and possible problems of the use of those interventions to achieve a healthy aging and longevity are discussed.

Peripheral immune system and neuroimmune communication impairment in a mouse model of Alzheimer's disease

“…In relation to the functional parameters of the immune cells we have analyzed, several have been proposed as biological age markers, such as chemotaxis, proliferation in response to mitogens (ConA and LPS), antitumoral NK activity, and IL‐2 secretion 2,6,7,12 . We have observed an age‐related decrease in these functions and that subjects with lower values of these parameters show an older biological age and earlier death than those with the same chronological age that have higher values 2,7,12 . Moreover, individuals reaching a high longevity (human centenarians and long‐lived mice) show these functions with values similar to those in healthy adults 2,11,27 .…”

“…This view proposes that aging is the consequence of the accumulation of damage by deleterious oxidation in biomolecules caused by the high reactivity of free radicals produced in cells as a result of the necessary use of oxygen. Thus, the age‐related changes in an organism are linked to chronic oxidative and inflammatory stress (a progressive imbalance between endogenous antioxidant/anti‐inflammatory and oxidant/proinflammatory compounds, with higher levels of the latter), which affects all cells, especially those of the regulatory systems, thus explaining their impaired function 2,6,7,12 . Moreover, oxidation and inflammation are the basis of immunosenescence.…”

“…With respect to the oxidative stress parameters analyzed (Table 3), both young adult and adult transgenic mice, compared with NTg animals, show a decrease in spleen antioxidant defenses, such as total glutathione (TG) levels and activity of GPx and GR antioxidant enzymes as well as an increase in xantin oxidase (XO) activity (an enzyme that produces oxidant compounds) 72,73 . These changes in antioxidants and oxidant compounds are characteristics of prematurely and chronologically aged subjects 2,12,16,74 . Thus, there is premature immunosenescence in the 3×Tg‐AD mice, which is underpinned by an oxidative stress state.…”

Immune function parameters as markers of biological age and predictors of longevity

“…In addition, these immune function parameters can be useful for the early identification of accelerated aging in humans, which may offer opportunities for prevention of age-related diseases and premature death. Furthermore, as the maintenance of health and consequently the rate of aging, principally depend on environment and lifestyle [16, 38], several strategies such as nutritional (caloric restriction or antioxidant administration) and physical exercise interventions, which can improve the immune response [39], are increasingly being used to slow down the aging process. However, as there is no accurate way of testing their effectiveness, the immune functions proposed in the present study will also be an aid for monitoring the effectiveness of such interventions.…”

Anti-Inflammatory Properties of Brazilian Green Propolis Encapsulated in a γ-Cyclodextrin Complex in Mice Fed a Western-Type Diet

“…It has been consistently shown that a so-called Western-type diet (WTD) rich in fat and sugars accelerates inflammatory processes in various tissues and organs, including the liver [14,15]. Furthermore, an increasing amount of experimental evidence suggests that ageing is accompanied by dysregulated immune and chronic inflammatory responses [16,17]. Thus, dietary strategies are needed to counteract diet- and age-related chronic inflammation.…”