Study of the toxicity of migration products from food contact materials for children under 3 years old

Bisphenol A (BPA) is a chemical compound mainly used for the manufacture of plastic such as polycarbonate. This transparent thermoplastic polymer is used for the fabrication of several food containers: bottle, baby bottle, tableware… BPA is found also in epoxy resins used as covers film in cans. BPA can migrate into food and beverages in contact with polycarbonate or epoxy resin.
There is a worldwide concern about BPA because several studies have shown endocrine disruptor potency of BPA causing possible adverse health effects.
In January 2011, the European Commission decided to ban the use of polycarbonate to manufacture baby feeding bottles and since 2013, Belgium extended this ban to all food contact materials intended to children younger than 3 years old. In a recent opinion, the Superior Health Council’s issued its concern regarding the currently use of alternatives to polycarbonate in these materials.
This work is part of the ALTPOLYCARB project which aims to study the migration products of alternative to polycarbonate and their endocrine disruptor activities.
The first part was to have an overview of the different polymers that are used on the Belgian market, which resulted in the conclusion that polymers used for the manufacture of baby bottles and tableware are mainly polypropylene, polyethersulfone, silicone, polyamide, polystyrene, and melamine. The second part of this work will be to evaluate the endocrine disruptor activity(ies) of global migration residues obtained from different kinds of baby bottles. This (these) activity(ies) will be explored using a cell based transactivational assay named “Chemically Activated LUciferase gene eXpression” (CALUX). Endocrine disruptors act by interfering with endogenous compounds, such as steroid hormones for example, for which the first step of their biological activity is the binding to an intracellular receptor, which is a factor of transcription regulation. The ligand-receptor complex is able to bind to DNA to induce the expression of the target gene at the level of the target tissue. The CALUX recombinant cells used here were stably transformed with the firefly luciferase gene, as a reporter gene, and a DNA responsive element specific to steroid receptors or to the dioxin receptor. The biological activity of a chemical compound (receptor agonist or antagonist) is monitored by the measurement of light emitted by the cells exposed to it (after addition of luciferin, the substrate of luciferase).
In a first step, human estrogen receptor agonistic and antagonistic activities of pure compounds (known to be used as altenatives to BPA) as well as baby bottles extracts will be measured using ER-CALUX cells (genetically modified MCF-7 cells), as well as cytotoxicity.
Preliminary test with 3 Bisphenols (BPs) have been performed: BPA, Bisphenol S (BPS) and Bisphenol F (BPF). The dose–response curves obtained for BPA, BPS and BPF were compared with that of 17β-estradiol (E2). An agonistic effect was observed with the 3 BPs. BPS and BPF exhibited oestrogen-like response comparable to or higher than that of BPA.
Further tests will be realised to confirm these preliminary results and similar tests will be realised with other cell-lines before beginning the evaluations of endocrine disruptor activities of global migration extracts.