PERINATAL EXPOSURE TO SUBSTANCES PRESENT IN PLANTS AND OTHER COMPOUNDS CAUSES THE DEVELOPMENT OF DISEASES DURING THE ADULT AGE, BY THE MECHANISM OF IMPRINTING

Since the first reports linking the development of clear cell cervicovaginal adenocarcinoma in young women with diethylstilbestrol treatment of their mothers during pregnancy, it became clear that prenatal or neonatal exposure to several substances may generate irreversible alterations, that can be detected later in life. Current evidence suggests that these substances induce, by the mechanism of imprinting, persistent alterations of the differentiation of several cell-types, which, in turn, are involved in the development of various diseases during the adult age. Among plant agents inducing imprinting mechanisms, the best known are phytoestrogens, caffeine, nicotine, fluoride, tetrahidrocannabinol, cocaine, opiate alkaloids, digoxin, Valeriana active agents and antithyroid compounds. Medicinal plants and agriculture derived food may be additionally contaminated by polluting agents known to induce imprinting mechanisms, such as lead, pesticides, nitrates and nitrites. Perinatal exposure to phytoestrogens may cause in adults female infertility, immune deficiency, increase in the incidence of infectious and autoimmune diseases and neurobehavioral alterations. Perinatal exposure to caffeine induces neurobehavioral changes, inhibits the differentiation of fetal Leydig cells and decreases the synthesis of fetal testosterone, which in turn alters subsequent development. Nicotine causes biochemical changes in brain, kidney and heart and, in rats, interferes with male sexual activity. Fluoride, present in tea, causes specific neurobehavioral deficit. Perinatal exposure to cocaine, tetrahidrocannabinol or opiate alkaloids causes in adults biochemical changes in brain and irreversible neurobehavioral impairment. Antithyroid compounds present in several Cruciferae food products, as well as in Araucaria araucana seeds, induces hypothyroidism in pregnant women, which causes in their offspring irreversible changes in levels and action of thyroid hormones. There exist a wide spectrum of pharmaceutical agents in medicinal plants that had not been investigated for their potential to induce the imprinting mechanism. The discovery of imprinting-mediated perinatal exposure delayed effects should incentive research in this new field of phytopharmacology.