Effects in vitro of several antioxidants on the natural killer function of aging mice☆

Ferrández, M.D.; Corrêa, Rosana Rosa Miranda; Rı́o, M. Del; Fuente, Mónica De la

doi:10.1016/s0531-5565(99)00009-1

Cited by 55 publications

(40 citation statements)

References 37 publications

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“…The senescent decrease in antioxidant levels supports the free radical theory of ageing, and provides a rationale for decreasing the rate of ageing by supplementing the diet with these antioxidants (Miquel & Weber, 1990). Previous studies from our laboratory, in old mice as well as in elderly men and women, have demonstrated the beneficial effects in vitro and in vivo, on the immune functions, of the antioxidants mentioned above (De la Fuente et al, 1998a,b;De la Fuente & Victor, 2000;Ferrández et al, 1999), and we should emphasize that an adequate immune system is a marker of health and longevity (Wayne et al, 1990). Moreover, the antioxidant doses should be higher in old animals than in the adult in order to improve the immune system (De la .…”

Section: Free Radicals and Antioxidants In The Immune Systemmentioning

confidence: 91%

Effects of antioxidants on immune system ageing

Fuente

2002

Eur J Clin Nutr

195

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One of the most widely accepted theories proposed to explain ageing is the free radical theory, according to which oxygenderived free radicals cause age-related impairment through oxidative damage to biomolecules, with mitochondria being the main target of free radical attack. Since oxygen radicals are needed for many metabolic and physiological processes, an equilibrium between radical production and their antioxidant-linked inactivation is required to preserve health. Thus, senescence is the result of an imbalance between free radical production and antioxidant defences, with concomitant oxidative stress and age-dependent functional decline. This process is especially evident in the immune cells, which use free radicals in their functions and suffer a senescent deterioration probably linked to oxygen stress. Conversely, several laboratories, including our own, have shown that antioxidants preserve an adequate function of immune cells against homeostatic disturbances caused by oxidative stress, such as that involved with age. Therefore, since the immune system is an indicator of health and a longevity predictor, the protection of this system afforded by dietary antioxidant supplementation may play an important role in order to achieve a healthy ageing.

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Section: Free Radicals and Antioxidants In The Immune Systemmentioning

confidence: 91%

Effects of antioxidants on immune system ageing

Fuente

2002

Eur J Clin Nutr

195

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“…23) Ferrández et al previously demonstrated that an age-dependent reduction in NK activity was improved by the existence of antioxidant agents such as ascorbic acid and a-tocopherol. 24) This result suggests that the antioxidant agents up-regulated NK activity through their protection against ROS. On the other hand, GT-catechins, especially EGCG, are known to work as potent radical scavengers and show antioxidative effects against various types of oxidative stress.…”

Section: Discussionmentioning

confidence: 95%

Preventive Effect of Green Tea Catechins on Experimental Tumor Metastasis in Senescence-Accelerated Mice

Shimizu

Hakamata

et al. 2010

Biological & Pharmaceutical Bulletin

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Tumor metastasis is a key step in the development of a tumor and becomes a critical trigger for the death of a patient. Hematogenous metastasis is established by a series of steps, which begin with the dissociation from primary sites and culminate with the formation of metastatic colonization.1) This process is greatly dependent on surrounding host factors such as host resistance to cancerous cells. 2,3) In a previous study, we demonstrated that the early accumulation of metastatic tumor cells in a target organ after intravenous injection of the cells and following tumor metastasis were enhanced by reduction of the host immune surveillance potential, 4,5) suggesting that avoidance of the surveillance associated with immune cells, such as natural killer (NK) cells, was a critical step for the completion of an experimental tumor metastasis.The senescence-accelerated mice prone (SAMP) strain has been established as a mouse model for aging research 6) and exhibits a more accelerated senescence process than normal mice. 7,8) By using this model, we found that the immune surveillance potential of 8-month-old aged SAMP10 mice was lower than that of 2-month-old young mice, and that the experimental lung metastasis was significantly induced in aged mice. These data suggest that the aging process produces an environment susceptible to metastatic tumor cells in the bloodstream to complete metastasis, and that such an environment is produced with age due to the reduced immune surveillance potential. 9)Green tea (GT)-catechins are functional polyphenols, and are known to have various actions, such as antibiotic, antiinflammatory, antioxidative, and anti-cancer effects. It is anticipated they will become useful as a functional food that promotes human health and longevity. Although animal studies have shown that GT-catechin treatment suppressed tumorigenesis, tumor growth, and tumor angiogenesis, 10,11) the crucial mechanism of the action of GT-catechin against cancer has not been fully elucidated. Our previous study demonstrated that (Ϫ)-epigallocatechin gallate (EGCG, a major component of GT-catechins) suppressed tumor angiogenesis through the inhibition of membrane type-1 matrix metalloproteinase (MT-1MMP) activity and subsequent induction of dormancy of solid tumor growth. 12,13) Tachibana et al. also reported that 67-kDa laminin receptors are a receptor for EGCG and that EGCG treatment inhibited the receptor-mediated signaling pathway and subsequent tumor cell growth.14,15) Several reports have described various such approaches to treat and prevent cancer using GT-catechins. In the present study, we hypothesized that GT-catechin intake modulates the immune surveillance potential in aged mice, and enhances the susceptibility to experimental tumor metastasis. To prove this, we exposed SAMP10 mice to GT-catechin in their drinking water for an extended period of time (aged/catechin mice) and examined their NK activity as an indicator of immune surveillance potential. We then also examined the accumulation of K1735M2 melanoma...

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“…A cepa Y de Trypanosoma cruzi possui picos parasitêmicos precoces, sendo altamente virulenta e patogênica, e produzindo uma alta mortalidade e lesões tissulares graves (Scorza e Scorza, 1972 (De La Fuente et al, 1998;Ferrandez et al, 1999). Além disso, animais tratados com T4C mostraram uma diminuição nos níveis de corticosterona (hormônio imunossupressor que diminui a resposta inflamatória) no soro (De La Fuente et al, 1998;Ferrandez et al, 1999) (Masoro, 2007).…”

Section: Discussionunclassified

“…Além disso, animais tratados com T4C mostraram uma diminuição nos níveis de corticosterona (hormônio imunossupressor que diminui a resposta inflamatória) no soro (De La Fuente et al, 1998;Ferrandez et al, 1999) (Masoro, 2007). Em um estudo, foi demonstrado que o ácido tânico, um polifenol de planta com atividades antioxidantes, anticarcinogênico e antimutagênico, prolonga a sobrevida de Caernorhabditis elegans e, além disso, melhora a resistência ao estresse por temperatura e aumenta, sutilmente, a resistência ao estresse oxidativo.…”

Section: Discussionunclassified

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Avaliação das perspectivas terapêuticas do ácido L-tiazolidina-4-carboxílico, um análogo de prolina, na infecção de camundongos pelo Trypanosoma cruzi.

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Effects in vitro of several antioxidants on the natural killer function of aging mice☆

Cited by 55 publications

References 37 publications

Effects of antioxidants on immune system ageing

Effects of antioxidants on immune system ageing

Preventive Effect of Green Tea Catechins on Experimental Tumor Metastasis in Senescence-Accelerated Mice

Avaliação das perspectivas terapêuticas do ácido L-tiazolidina-4-carboxílico, um análogo de prolina, na infecção de camundongos pelo Trypanosoma cruzi.

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