Goodbye Endocrine Disruption!

By Shivanthi Sriskandha, Member-at-Large for the GCI

A recent study published in the Royal Society of Chemistry journal, Green Chemistry, has aimed to bridge the gap between chemists and toxicologists in the design of safer, sustainable chemical products. The paper is authored by 23 scientists in the fields of green chemistry, biology, and environmental health science, and proposes a protocol to effectively develop compounds that will not cause endocrine disruption.

Oral contraceptives contain a combination of estrogen and progestogen, known EDCs that have implications on fish and other wildlife.

Endocrine disruption occurs when an agent or mixture of chemicals interferes with any aspect of hormone action. Common endocrine-disrupting chemicals (EDCs) include BPA, DDT, flame retardants, and phthalate-containing products. As such, the primary concern is exposure to these chemicals in consumer products. Research has now shown that EDCs can affect human metabolism, liver, and bone function as well as have an impact on diabetes, obesity, infertility, and learning disorders.

Currently, environmental performance and sustainability are not taken into account when designing new chemicals, or at least not emphasized enough. Furthermore, chemists have a limited knowledge of toxicology and therefore aren’t trained to evaluate toxicity risks. For these reasons, the Tiered Protocol for Endocrine Disruption, or TiPED, system was invented to guide chemists towards the design of safer materials.

Pesticides and herbicides used for agricultural and domestic purposes are common sources of EDCs.

The 5-tiered TiPED system combines principles in green chemistry with new methods of toxicology to form a comprehensive system that will evaluate a new chemical’s toxicity. The system is designed so that the user has the ability to enter the process at any stage in order to best meet the user’s needs. In each tier, a pass-fail grade is given to the chemical in question. If it passes, it is allowed to move onto the next stage for further testing. If it fails, it must go back to the drawing board to be reassessed. Since the current protocol cannot detect all possible mechanisms of endocrine disruption (an area of science that is still in progress), updates to the protocol will be made on the peer-reviewed TiPED website as they are developed.

TiPED

The proposed tiered test for endocrine disruption, TiPED.[1]

Here’s how the Tiers work:

  • Tier 1: Computational approaches that can assess the chemical compound by searching existing databases for known EDCs and by predicting endocrine-disrupting behaviour using computer models.
  • Tier 2: Cell-based assays that directly test a chemical’s ability to interact with and affect the activity of targeted proteins, hormone receptors, and genes.
  • Tier 3: Assesses the activity of a test chemical on an endocrine-signaling pathway that may lead to cell division, differentiation or death, or to endocrine-mediated processes.
  • Tier 4: Determines chemical impacts on fish and amphibian reproductive cycles, development and behaviour.
  • Tier 5: Mammalian testing to mimic responses in humans.

Overall, consumer awareness of the harm in commercial products is leading to the development of safer chemicals and greater collaboration between various scientific disciplines to make our world a healthier place.

For further information, please see the companion website: www.TiPEDinfo.com where you can gain access to the paper and consult the formal protocol on the TiPED system.

References:

[1] T. T. Schug et al., “Designing endocrine disruption out of the next generation of chemicals”, Green Chem. 2013, 15, 181-198.

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