Editor’s Note

Hi, Everyone!

This issue of International Journal of Toxicology contains something for everyone! The issue leads off with two “sister articles” that present species differences and threshold effects with Tween 80 in dosing formulations. I learned, via perusing the web, as well as reading peer-reviewed published literature, that Tween 80, also known as Polysorbate 80, is included in a wide range of products used by humans, ranging from ice cream, to cosmetic and personal care products, to drug formulations. The papers in this issue focus on Polysorbate 80-induced anaphylactoid reactions. I read these with great interest, and learned a lot; I am quite sure that many of our readers will benefit, as well.

We also included in this issue an article that is a bit unusual in its focus for International Journal of Toxicology. Le Dare et al. provide us with an example of the use of high resolution mass spectrometry analysis of a drug mixture, followed by molecular networking and metabolite annotation, to complement traditional forensics techniques to identify components of seized drug powders.

Two review articles are also available for your reading pleasure. Both have tremendous potential for use in training students in the classroom, as well as early career scientists. Choudhuri presents a review of macromolecular diversity and biological heterogeneity in biological systems. Kale and colleagues contributed an overview of practical considerations in determining adversity and the NOAEL in nonclinical safety studies. While this entire article is interesting and informative, the case studies will certainly be great teaching examples.

Glyphosate is the topic of ongoing debate world-wide, as it is the active ingredient in many widely-used herbicide formulations, and its use has prompted the development of genetically-modified crops that can resist glyphosate’s herbicidal activities. Glyphosate was originally felt to be “safe”, because it targets a molecular pathway not found in mammals (specifically, glyphosate inhibits the enzyme 5-enolpyruvylshikimate-3-phosphate synthase, which is responsible for biosynthesis of aromatic amino acids via the shikimate pathway in plants). However, the expanding use of glyphosate-containing formulations, such as Roundup™, has put this active ingredient under scrutiny as a possible contributor to adverse health effects in agricultural workers, as well as human cancer.^1,2 Part of what makes this whole issue difficult to interpret is that, while it is known that glyphosate is an active ingredient in many herbicidal formulations, the other components of these formulations, often regarded as “inert”, may be unknown to those individuals using the products, but may contribute to adverse effects that are often attributed to the active ingredient glyphosate itself. Studies previously published in this journal demonstrate differences in toxicity in rodents between glyphosate alone, compared to commercial glyphosate formulations, with the formulations proving to be more toxic than the active ingredient alone.^3,4 Studies by Tarboush and collaborators in this issue add to the large body of knowledge that suggest, in toto, that glyphosate is weakly, or non-genotoxic (and weakly, or non-mutagenic).

Finally, the role of microRNAs in disease and responses to environmental exposures is a growing field. MicroRNAs (miRNAs) alter cell signaling pathways by repressing gene transcription. ⁵ In this issue of International Journal of Toxicology, data presented by Wu et al. demonstrate that miRNA-185-5p suggest that this microRNA can target cathepsin E to represses cell growth and metastasis in primary and metastatic osteosarcoma cells in vitro. Because of the emerging discoveries on the biological functions of microRNAs, one of our journal’s special collections features papers published in our journal on miRNAs. This collection, along with several others, can be found on the Journal tab of the American College of Toxicology (ACT) website. To view our collections, login as a member of ACT and scroll to the bottom to see the recently-updated microRNA collection.

So, please, read, enjoy, and learn from this issue. As always, I am delighted to hear from you with suggestions and comments. My very best to all!