Use of Saccharomyces cerevisiae and Caenorhabditis elegans as Model Organisms To Study the Effect of Cocoa Polyphenols in the Resistance to Oxidative Stress

Abstract

Developing functional foods to improve the quality of life for elderly people has great economic and social impact. Searching for and validating ingredients with in vivo antioxidant effects is one of the key steps in developing this kind of food. Here we describe the combined use of simple biological models and transcriptomics to define the functional intracellular molecular targets of a polyphenol-enriched cocoa powder. Cocoa powder supplemented culture medium led to increased resistance to oxidative stress, in both the budding yeast Saccharomyces cerevisiae and the nematode Caenorhabditis elegans, and, in the latter, lifespan was also increased. These effects are fully dependent on the polyphenols present in the cocoa powder and on the sirtuins Hst3 (yeast) and SIR-2.1 (worm). The transcription factor DAF-16 also plays an important role in the case of the nematode, indicating that the insulin/IGF-1 (insulin-like growth factor) signaling pathway is related with the antioxidative effect of cocoa polyphenols. All in all, these results confirm that this polyphenol-enriched cocoa powder, with antioxidant activity, has great potential use as a functional food ingredient for elderly people. Furthermore, this work reveals the value of using simple biological models to screen for compounds that are of interest for the food and pharmacological industry.

The longevity effect of cranberry extract in Caenorhabditis elegans is modulated by daf-16 and osr-1

“…Blueberry extract promotes longevity in C. elegans and Drosophila (Peng et al 2012;Wilson et al 2006). Cocoa contains abundant flavonoids and promotes longevity and resistance to oxidative stress in worms (Martorell et al 2011). Nectarine and açai extracts promote the survival in Drosophila under oxidative stress and fed high-fat diets (Boyd et al 2011;Sun et al 2010).…”

Towards application of genetic engineering in citriculture: 1) assessing dispersal, long-term stability and phenotypic impact of transgenes in citrus trees and 2) improving nutri-functional quality of orange fruit through metabolic engineering

“…The biofortified oranges exerted a higher protective effect than control oranges despite its slightly lower content of xanthophylls (oxygenated carotenoids also described as dietary antioxidants (Haegele et al, 2000)), which supports the strong antioxidant effect of dietary β-carotene reported in previous studies (Jialal et al, 1991;Meydani et al, 1994;Nakagawa et al, 1996). The effect of dietary β-carotene against oxidative stress achieved in this work (70% worm survival after hydrogen peroxide treatment) is similar to the effect reported for cocoa polyphenols (Martorell et al, 2011) and Tonalin (a conjugated linoleic acid commercial mixture) (Martorell et al, 2012). The mechanism of the antioxidant activity of β-carotene is related to this compound's hydrophobic character and ability to quench singlet oxygen and deactivate free radicals (Burton and Ingold, 1984;Rice-Evans et al, 1997).…”

“…Establishment of a C. elegans system to evaluate the in vivo antioxidant effect of orange juice C. elegans has been widely used as a model to study the in vivo antioxidant capacity of different pure compounds and certain plant extracts (Artal-Sanz et al, 2006;Martorell et al, 2011;Martorell et al, 2012;Van Raamsdonk and Hekimi, 2010) but not the juice from fruits or vegetables. Therefore, it was necessary to optimize certain essential aspects concerning the experimental method prior to performing the bioassays with the orange fruit.…”

Flavonoids: Antioxidant Compounds for Plant Defence... and for a Healthy Human Diet

“…elegans; these effects were fully dependent on the polyphenols present in the cocoa powder and on SIR-2.1, a worm sirtuin (Martorell et al, 2011).…”