September 2014 Biol. Pharm. Bull. 37(9) 1429 (2014) 1429 Current Topics Recent Advances in the Mechanistic Understanding of Endocrine Disruption by Environmental Chemicals

Foreword Hironori Aramaki Department of Molecular Biology & Drug Innovation Research Center, Daiichi University of Pharmacy; 22–1 Tamagawa-cho, Minami-ku, Fukuoka 815–8511, Japan.

Chemicals, which have endocrine-disrupting potential, uni- a biologically active constituent of marijuana, which disrupts versally exist in the environment or diet that can interfere with the estrogen (E2)/estrogen receptor α (ERα)-mediated signal- normal hormone biosynthesis, metabolism and signaling, thus ing by acting as an anti-estrogen. Since Δ9-THC exhibits no causing adverse/negative health effects on humans and ani- binding potential to ERα, there has been a big question of mals. Endocrine-disrupting chemicals (EDCs) are found in a how Δ9-THC abrogates the E2/ERα activities. Very recently, variety of different sources, like industrial chemicals/pharma- his research group reported evidence suggesting that ERβ, a ceuticals (see Dr. Shimizu’s section), phytochemicals (see Dr. second type of ER, is involved in the Δ9-THC inhibition of Takeda’s section), and pesticides (Dr. Hoshi’s section). This E2/ERα signaling through ERα/ERβ interaction. Dr. Hoshi current publication entitled “Recent Advances in the Mecha- provides new insight into the neonicotinoid pesticides which nistic Understanding of Endocrine Disruption by Environ- have negative effects on the reproductive functions of en- mental Chemicals” provides readers with recent findings on dangered animals, including the Japanese crested ibis. His environmental chemicals (EDCs) which cause endocrine dis- research group demonstrated that daily oral administration of ruption, and also offers a chance to understand the pesticides the neonicotinoid clothianidin (CTD) could damage the birds’ in the environment that disrupt birds’ reproductive system. reproductive system through reactive oxygen species (ROS) The publication is composed of three review articles, each production. This was achieved by down-regulation of glutathi- written by a leading scientist in his field. Dr. Shimizu summa- one 4 (GPx4) and manganese rizes findings on the hormone-disrupting action by en- (Mn-SOD) which have the potential to protect the organism vironmental chemicals; based on his recent study he provides from oxidative stress. Based on that report, it has been dem- results on the effects of environmental halogenated chemicals, onstrated that the Japanese crested ibis can be bred without including food colorants (e.g., rose bengal and erythrosine B), the use of neonicotinoids. on iodotyrosine (IYD) activity, which is involved I hope that you, the audience, will better understand the in iodide salvage by catalyzing deiodination of iodinated by- molecular mechanisms of endocrine disruption by environ- products of thyroid hormone production. He also provides evi- mental chemicals after reading this volume, and will recon- dence of the structural requirements in the inhibition of IYD sider the present circumstances of EDC exposure. The editor by these environmental halogenated chemicals. Dr. Takeda in- of this Current Topics gratefully acknowledges the authors’ troduces the mechanism of Δ9-tetrahydrocannabinol (Δ9-THC), significant contributions.

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