Relationship between toxic effects of potassium bromate and endocrine glands

Abstract

Potassium bromate (KBrO₃) is a compound belonging to Group 2B of carcinogens (a possible human carcinogen). This agent was used as a food additive in flour treatment, as a component of cold-wave hair lotions, and is still used in barley processing. Additionally, KBrO₃ is formed as an oxyhalide by-product during water ozonation.
KBrO₃ induces oxidative stress and may contribute to neoplasia in endocrine glands. It has been demonstrated that KBrO₃ triggers thyroid follicular cell tumors in rats. It has been revealed in our in vivo and in vitro studies that KBrO₃ significantly increases lipid peroxidation in rat and porcine thyroid. KBrO₃ also induces mesotheliomas which may secrete hormones or similar substances, such as parathyroid hormone related protein, phosphatonins or melanocyte stimulating hormone.
In our experimental studies we demonstrated that antioxidants, such as pineal hormone - melatonin, indole-3-propionic acid (IPA) (a compound chemically and physically similar to melatonin) and antythyroid drug - propylthiouracil (PTU), produce distinct protective effects against lipid peroxidation due to KBrO₃ in the thyroid in vivo.
KBrO₃ is a prooxidant which may induce neoplasia in endocrine glands and cause hormonal disturbances, however its damaging effects may be neutralized by hormones, mainly melatonin.