What Caught Our Attention: The researchers were studying how curcumin, a component of the spice turmeric, can inhibit lung cancer metastases. But upon learning that the primary material had been expired at the time of testing (and realizing they were unable to repeat their experiments), the researchers pulled their paper. Expiration dates do have safety factors built in, but attention to such details is imperative in research.
Journal: PLoS One
Authors: De-min Jiao, Li Yan, Li-shan Wang, Hui-zhen Hu, Xia-li Tang, Jun Chen, Jian Wang, You Li, and Qing-yong Chen
Affiliations: The 117th Hospital of PLA, China; Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, China
After publication of this article, the corresponding author, Qing-yong Chen, notified the editorial office that the curcumin used in this study was expired at the time of use. The authors expressed concern that this may have affected the results of the MTT assays and microarray expression experiments reported in the article; they are unable to repeat the experiments at this time. Due to concerns about the validity of the data and results reported in this work, the authors and the PLOS ONE Editors retract this article.
Date of Article: February 2017
Times Cited, according to Clarivate Analytics’ Web of Science: Zero
Date of Notice: November 30, 2017
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Somehow I feel that all these “herbal supplement cures cancer” papers fail to replicate for reasons other than the herbal supplement having gone past its expiration date.
Certainly, if the expiration is the only reason, the authors can order curcumin and do the same experiment after it expires.
Re ” the curcumin used in this study was expired at the time of use”, expired of what? Such products in the store usually have Best Before date, rather than Expiration date. Is that a valid excuse to invalidate experimental data, if there were any real data obtained in the lab?
The problem is maybe the curcumin itself according to these authors: https://pubs.acs.org/doi/abs/10.1021/acs.jmedchem.6b00975
It was a curcumin extract made in the US.
Therefore probably “expiration date” correct.
The next trial with a different cell line can get different results, without the researchers making any mistake. If I understand the retraction, the research group had to use a different curcumin concentrate AND used a different cell line, and got none of the measured activities of the first experiment.
And it was no “herbal supplement” – that would be if I eat turmeric in my meals often – and TL, yes, curing cancer that way is not probable – primary prevention, not getting cancer, maybe (still the probability depending on risky genes, therefore different for different people and not easy to test)
It seems more likely that it wasn’t what it was stated to be, than just ‘expired’.
the primary material had been expired at the time of testing (and realizing they were unable to repeat their experiments)</i.
A plot device in "Dr Jeckell & Mr Hyde": subsequent batches prepared from new stocks failed to work. Jekyll speculated that one of the original ingredients must have some unknown impurity that made it work.
Also “The Novel of the White Powder”.
The retraction says, “they are unable to repeat the experiments at this time. “
there’s an interesting discussion on research gate about shelf life of curcumin. It looks like there may be an expiration date and some people found it less effective (whatever it means) after a while.
https://www.researchgate.net/post/What_is_the_shelf_life_of_curcumin_Is_there_any_way_to_improve_it
It is an arguable deposition to claim that a Herbal material has an expiring date because of its natural components that are well conserved. But the scientific extractions and conservative procedures of the components of this material could be questioned.
Paul Clardy is correct, the problem with this paper is the fact that it is even investigating the effect of curcumin – a molecule that is a pan-assay inhibitory compound. You will definitely get a result if you put it into your assay, but it is a non-specific inhibitor. It also has properties which make it, or derivatives, unsuitable or use as a drug. Further research on curcumin is essentially wasted money and time, and is bad science.
http://pubs.acs.org/doi/10.1021/acs.jmedchem.6b00975
If the product had expired and the results were negative I’d understand the need to withdraw the paper. How does the expiry date affect these results?
Maybe the retraction is written poorly, but do they mean they tried to replicate the study, but failed to get similar results, or that circumstances, such as time, money, etc, prevents them from even attempting a repeat study? I suspect the later as they say, “hey are unable to repeat the experiments at this time.”… note “…at this time…”
Should read, “They are unable to repeat the experiments at this time.”… note “…at this time…”