Food Emulsifier Glycerin Monostearate Increases Internal Exposure Levels of Six Priority Controlled Phthalate Esters and Exacerbates Their Male Reproductive Toxicities in Rats

PLoS One. 2016 Aug 30;11(8):e0161253. doi: 10.1371/journal.pone.0161253. eCollection 2016.

Abstract

Human beings are inevitably exposed to ubiquitous phthalate esters (PAEs). Processed, packaged foods are popular nowadays, in which emulsifiers are frequently added as food additives. It is unclear how emulsifiers affect the bioavailability of ingested PAEs contaminants and their toxicities. The purposes of our study were to explore whether food emulsifier Glycerin Monostearate (GMS) could increase the internal exposure levels of six priority controlled PAEs and affect their reproductive toxicities when male rats are exposed to PAEs mixture (MIXPs). The male rats were exposed to MIXPs by gavage for thirty days in combination with or without given GMS. Phthalate monoesters (MPAEs), primary metabolites of PAEs, in rat urine were used as biomarkers to predict the internal exposure levels of the six PAEs, and their concentrations were determined using UPLC-MS. The reproductive toxicity was evaluated using serum testosterone levels test and histopathology of testes. Results showed that compared to PAEs exposure alone, the internal exposure levels of PAEs increased by 30%-49% in the presence of GMS. PAEs exposure led to the reduction of testosterone level by 23.4%-42.1% in the presence and absence of GMS, respectively, compared to the baseline. Testosterone levels in MIXPs+GMS and DEHP+GMS group were decreased by 9.1% and 13.6%, respectively, compared with MIXPs and DEHP group. Histopathology showed that injuries of testis (deciduous spermatids) were observed, and GMS exacerbated the injuries. The results indicated food emulsifiers chronically taken up might increase safety risks of food PAEs contaminants.

MeSH terms

  • Animals
  • Chromatography, Liquid
  • Emulsifying Agents / adverse effects*
  • Emulsifying Agents / pharmacology
  • Esters / adverse effects*
  • Esters / chemistry
  • Esters / pharmacology
  • Food Additives / adverse effects*
  • Food Additives / pharmacology
  • Glycerol / adverse effects
  • Glycerol / chemistry
  • Glycerol / pharmacology
  • Male
  • Mass Spectrometry
  • Phthalic Acids / toxicity*
  • Phthalic Acids / urine
  • Rats
  • Rats, Sprague-Dawley
  • Reproduction / drug effects*
  • Testis / drug effects
  • Testosterone / blood

Substances

  • Emulsifying Agents
  • Esters
  • Food Additives
  • Phthalic Acids
  • Testosterone
  • Glycerol

Grants and funding

This work received financial support from Socail Development Research Program of Jiangsu Province Science and Technology Department (http://xmsb.jschina.com.cn/indexAction!to_index.action) Project No.: BE2015646, to QX, Maternal and Child Healthcare Project of Jiangsu Province Health Department (http://www.jswst.gov.cn/jsswshjhsywyh/index.html) Project No.:F201407, to YS, Youth Fund Project of Jiangsu Province Health Department (http://www.jswst.gov.cn/jsswshjhsywyh/index.html) Project No.:Q201305, to QX, Science and Technology Project of Nanjing City (http://www.njkj.gov.cn/) Project No.:201201054, to QX, and Student Research Training Program (http://srtp.seu.edu.cn/) 1510286111, to XZ. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.