Most of our readers are biologists but nevertheless we are occasionally exposed to medicinal chemistry literature describing novel research tools, lead molecules or drug candidates. Medicinal chemistry papers often include evidence from animal research supporting certain qualities of novel chemical entities. Like us, you may have noticed that, while the chemistry methods are presented with lots of details, biology sections tend to be very short.
To test this subjective impression, we have retrieved all papers published since the beginning of 2020 in three leading medicinal chemistry journals – two journals from the American Chemistry Society (Journal of Medicinal Chemistry [JMC] and ACS Chemical Neuroscience [ACN]) and the European Journal of Medicinal Chemistry (EJMC). These journals have more or less the same reader audience and have comparable conventional impact factors.
From a total of 1,413 papers, we have randomly selected 15 research papers from JMC and ACN and another 15 papers from EJMC (a total of 30 papers) that met the following criteria: i) reporting the discovery of a novel chemical entity, and ii) reporting at least one in vivo experiment in a mammalian species.
For EJMC, the Guide for Authors states: “All animal experiments should comply with the ARRIVE guidelines and should be carried out in accordance with the U.K. Animals (Scientific Procedures) Act, 1986 and associated guidelines, EU Directive 2010/63/EU for animal experiments, or the National Institutes of Health guide for the care and use of Laboratory animals (NIH Publications No. 8023, revised 1978) and the authors should clearly indicate in the manuscript that such guidelines have been followed.”
For JMC, the Guide for Authors states: “Research involving animals must be performed in accordance with institutional guidelines as defined by Institutional Animal Care and Use Committee for U.S. institutions or an equivalent regulatory committee in other countries.
A statement confirming that all animal experiments performed in the manuscript were conducted in compliance with these guidelines is required. In the experimental section, the source, age, sex, species, and strain of animals should be included.”
For ACN, the Guide for Authors states: “Papers reporting data from experiments on live animals must include a statement identifying the approving committee and certifying that such experiments were performed in accordance with all national or local guidelines and regulations.”
Here is an overview of the information we have retrieved from this sample of 30 papers:
| Eur J Med Chem(n=15) | ACS journals(n=15) | All journals(N=30) | |
| Statement about compliance with NIH guidelines, EU Directive, or national animal welfare law | 5 (33%) | 4 (27%) | 9 (30%) |
| Statement on approval of animal study protocol by any local body | 10 (67%) | 7 (47%) | 17 (57%) |
| Any information on animal housing and husbandry | 7 (47%) | 1 (7%) | 8 (27%) |
| Supplier or breeder of animals identified | 12 (80%) | 6 (40%) | 18 (60%) |
| Any information on any of the Landis 4 criteria for any of the experiments (randomization, blinding, sample size estimation, inclusion / exclusion criteria) | 9 (60%)(randomization only) | 5 (33%)(randomization in 4 papers and blinding in one) | 14 (47%) |
Our analysis is based on a very small sample and this is a clear limitation that prevents us from making too many conclusions.
However, even with this limited sample, we are able to confirm that reporting of in vivo experiments in medchem journals needs to improve.
Further, the Guide for Authors does apparently have an impact on what is eventually reported by the authors. Hence, editors and publishers should be encouraged to revisit their author guides to enhance rigor and transparency in reporting the results of in vivo experiments.
Some of our chemist colleagues argue that, for a chemistry paper, the primary focus should be on chemistry and it is therefore justified that biology results are not presented as they would normally be presented in pharmacology journals. We do not agree. Do you?
