Use of Medaka Fish as Vertebrate Model to Study the Effect of Cocoa Polyphenols in the Resistance to Oxidative Stress and Life Span Extension

Abstract

Oxidative stress (OS) can induce cell apoptosis and thus plays an important role in aging. Antioxidant foods protect tissues from OS and contribute to a healthier lifestyle. In this study, we described the used of medaka embryos (Oryzias latipes) to study the putative antioxidant capacity of dietary cocoa extract in vertebrates. A polyphenol-enriched cocoa extract regulated the expression of several genes implicated in OS, thereby protecting fish embryos from induced OS. The cocoa extract activated superoxide dismutase enzyme activity in embryos and adult fish tissues, suggesting a common mechanism for protection during embryonic development and adulthood. Furthermore, long-term feeding of the cocoa extract increased fish life span. Our study demonstrates that the polyphenol-enriched cocoa extract decreases OS and extends life span in medaka fish, validating the use of medaka embryos as an economical platform to screen the antioxidant capacity of food compounds.

Cocoa improves age-associated health and extends lifespan in C. elegans

“…In the same study, cocoa increased average lifespan of D. melanogaster under hyperoxia or in a Cu/Zn-superoxide dismutase-deficient background, suggesting that it has strong antioxidant properties. Moreover, it has been previously reported that polyphenol-rich extracts of cocoa powder increased the lifespan of rats [42], Saccharomyces cerevisiae [43] and Oryzias latipes [44]. Conversely, catechin and epicatechin (two major flavanols in cocoa) showed no improvement in mean lifespan of C. elegans in another study [45].…”

Medaka (Oryzias latipes) Embryo as a Model for the Screening of Compounds That Counteract the Damage Induced by Ultraviolet and High-Energy Visible Light

“…Medaka embryos are used for toxicity assays, screening of antioxidant molecules [ 24 ], or functional food [ 25 ]. Therefore, we wanted to compare the two more economic models as platforms for protective molecules against sunlight irradiation.…”

“…For this reason, the use of fish embryos, like Zebrafish or Medaka fish, as an alternative in vitro model provides many advantages [ 18 , 19 ]. This model has been extensively used in several research disciplines such as development biology [ 20 ], human disease model [ 21 , 22 , 23 ], and even screening for antioxidant molecules [ 24 ] or functional food [ 25 ]. Medaka fish embryos have a great number of advantages to be used as a screening platform for antioxidant and sunlight protective products, such as their economic maintenance and experimentation, their small size and transparent chorion that allow researchers to observe them using a simple loupe, the availability of a high number of daily embryos, and the presence of all cell types, tissue and organs interactions [ 26 ].…”

Pleiotropic Biological Effects of Dietary Phenolic Compounds and their Metabolites on Energy Metabolism, Inflammation and Aging

“…Regarding the lifespan extension, in medaka fish, the activation of the SIRT1 protein did not occur directly but was done indirectly in a similar way to that produced in mammals. The extract activated Epac1, a cAMP effector protein, which leads to high levels of CAMP and indirectly activates the enzymatic function SIRT1 [102].…”