Iodine Bioavailability and Biochemical Effects of Brassica oleracea var. sabellica L. Biofortified with 8-Hydroxy-7-iodo-5-quinolinesulfonic Acid in Wistar Rats

Abstract

Background: Iodine is one of the essential trace elements for human life. The main objective of the biofortification of plants with iodine is to obtain food with a higher content of this element compared to conventional food. Biofortification of plants with iodine can increase the intake of this trace element by different populations. In addition, it may reduce the risk of iodine deficiency diseases. Objectives: The aim of the study was to investigate the effect of kale biofortified with 8-hydroxy-7-iodo-5-quinolinesulfonic acid (8-OH-7-I-5QSA) on iodine bioavailability and biochemical effects in Wistar rats. Methods: Kale biofortified with (8-OH-7-I-5QSA) was tested for iodine levels in urine, feces, and selected tissues using the ICP-MS/MS technique. The feeding experiment was designed to investigate potential changes in selected thyroid-regulated biochemical parameters in blood serum of Wistar rats. Results: The dietary intake of Wistar rats fed kale biofortified with (8-OH-7-I-5QSA) from both the “Oldenbor F1” and “Redbor F1” cultivars for 8 weeks resulted in significantly (p ≤ 0.05) higher iodine concentrations in the urine and kidneys of rats, which proves iodine bioavailability. Rats’ diets with “Oldenbor F1” and “Redbor F1” kale non- and -biofortified with 8-OH-7-I-5QSA had a significantly (p ≤ 0.05) lower or a tendency for lower concentration of TSH, triglyceride, total and direct bilirubin, TBARs, uric acid, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) concentrations in serum. Dietary intake of “Oldenbor F1” and “Redbor F1” kale biofortified with 8-OH-7-I-5QSA significantly (p ≤ 0.05) increased the total antioxidant status (TAS). Conclusions: Our study confirms that kale biofortified with iodine in organic form iodoquinoline 8-OH-7-I-5QSA is bioavailable and well absorbed by the Wistar rat and has a positive effect on selected biochemical parameters. The results obtained in this study may be highly predictive for further studies in humans.