Estrogen-like endocrine disrupting chemicals affecting puberty in humans--a review

Abstract

Estrogen-like endocrine disrupting chemicals (EEDC) are exogenous, man-made chemicals that alter the functions of the endocrine system and cause various health defects by interfering with the synthesis, metabolism, binding or cellular responses of natural estrogens. EEDCs have been found in various plastic products, flame retardants, pesticides and many other products that are needed for daily use. Some of the greatest effects of EEDCs are on puberty, a period of rapid physiological changes like growth spurt, maturation of the gonads and the brain. Estrogen, one of the key hormones required in puberty is crucial for the sexual differentiation. The structural similarity of estrogen disruptors with estrogen allow them to bind and activate estrogen receptors and show a similar response even in the absence of estrogen that can lead to precocious puberty (PP). Major EEDCs found abundantly in our environment include; dichlorodiphenyltrichloroethane (DDT), dioxin, polychlorinated biphenyls (PCBs), bisphenol A (BPA), polybrominated biphenyls (PBB), phthalate esters, endosulfan, atrazine and zeranol. In girls, DDT has been linked to earlier menarche. Dioxin causes abnormal breast development in pre-pubertal girls. BPA has shown to cause PP in pubertal girls. PBB causes earlier menarche, thelarche and earlier pubic hair stage in pubertal girls. PCB's showed a significant delay in puberty in pubertal boys. De-feminization, thelarche, or early secondary breast development are shown in pubertal girls when exposed to phthalate esters. Endosulfan affects pubertal boys by slowing down the timing of reproductive maturation. This article provides a possible structure-function relation of the above mentioned EEDCs which interfere with sexual development during puberty.