Bioavailability studies on saffron carotenoids using in vitro models

Anastasia Kyriakoudi visited Prof. Nora O'Brien in Ireland (31 days in March 2012)

Among bioactive compounds, carotenoids are of great importance since their consumption has been associated with reduction of risk from various diseases. According to Aherne et al. (2009) in addition to knowing the carotenoid content of foods, it is important to obtain information on how much of these ingested phytochemicals are actually available, after digestion, for absorption by intestinal cells (i.e. bioaccessible). Despite the fact that various studies have substantiated the bioaccesibility of carotenoids such as β-carotene and its isomers, lycopene, lutein, zeaxanthin, and β-cryptoxanthin from herbs and vegetables (Daly et al., 2010, Aherne et al. 2009) there are no data on the bioaccessibility of saffron (Crocus sativus L. dried stigmas) carotenoids (i.e. crocins).

Therefore, the main research target of this exchange visit was to assess the bioaccessibility of saffron in dry or extract form or even of isolated compounds (i.e. crocetin) using proper in vitro models, which simulate human digestion.

The bioaccessibility of crocins, which are unusual water-soluble carotenoids (Carmona et al., 2006) was found to be higher than that of lipophilic carotenoids that are reported in the literature, which is in line with the hypothesis that carotenoid bioaccessibility is inversely proportional to the hydrophobicity of the carotenoid (Van het Hof, et al., 2000).

Additionally, despite saffron use in traditional medicine, its biological activity is in development (Ordoudi et al., 2009). Therefore, the protective effect of crocins, as well as the pure crocetin, against H₂O₂-induced DNA damage, were also tested by means of the comet assay (Single Cell Gell Electrophoresis, SCGE) (Liao et al., 2009). All of the tested samples showed a protective effect against H₂O₂-induced DNA damage, whereas the pure crocetin displayed the most protective effect.

References

• Aherne, S.A., Jiwan, M.A., Daly, T., O’Brien, N.M., Geographical location has greater impact on carotenoid content and bioaccesibility from tomatoes than variety. Plant Foods Hum Nutr, 2009, 64, 250-256.
• Carmona, M., Zalacain, A., Sanchez, A.M., Novella, J.L., Alonso, J. L., Crocetin Esters, Picrocrocin and Its Related Compounds Present in Crocus sativus Stigmas and Gardenia jasminoides Fruits. Tentative Identification of Seven New Compounds by LC-ESI-MS. J. Agric. Food Chem., 2006, 54, 973-979.
• Liao, W., McNutt, M. A., Zhu, W.G., The comet assay: A sensitive method for detecting DNA damage in individual cells. Methods, 2009, 48, 46-53.
• Ordoudi, S. A., Befani, C.D.,  Nenadis, N.,  Koliakos, G.G., Tsimidou, M.Z., Further Examination of Antiradical Properties of Crocus sativus Stigmas Extract Rich in Crocins. J. Agric. Food Chem., 2009, 57, 3080–3086.
• Van het Hof, K., West, C., Weststrate, J., Hautvast, J., Dietary factors that affect the bioavailability of carotenoids. J Nutr, 2000, 130, 503-506.