Differential effects on adiposity and serum marker of bone formation by post-weaning exposure to methylparaben and butylparaben.

Paraben esters and their salts are widely used as preservatives in cosmetics, personal care products, pharmaceuticals, and foods. We and others have reported that parabens promote adipogenesis in vitro. Here, we investigated the effects of post-weaning exposure to parabens (methylparaben and butylparaben) on body weight, white adipose tissue mass, and obesity associated metabolic biomarkers in female obesity-prone C57BL/6J mice fed with a chow diet or a high fat diet. Methylparaben exposure by daily oral gavage (100 mg/kg/day) increased adiposity and serum leptin levels compared to the controls when fed the chow diet, but not the high fat diet. In contrast, butylparaben exposure did not induce such effects. Exposure to either paraben induced changes in gene expression related to adipocyte differentiation and lipogenesis in the white adipose tissue (WAT) and the liver, regardless of diet. Moreover, exposure to both parabens under the chow diet significantly decreased serum procollagen type 1 N-terminal propeptide (P1NP) but had no effects on C-terminal telopeptide of type I collagen (CTX-I) levels, suggesting that post-weaning exposure to paraben may negatively affect bone formation, but not bone resorption. Taken together, our results demonstrate that post-weaning exposure to paraben, methylparaben in particular, promotes adipogenesis but suppresses serum marker of bone formation in vivo. Our results add to the growing body of literature indicating potential negative health outcomes associated with paraben exposure. Further study of early life exposure to paraben on the development of fat and bone is warranted.