About these ads

Retraction Watch

Tracking retractions as a window into the scientific process

Mislabeled chemical bottle leads to retraction of liver protection paper

with 5 comments

molecules-logoA labeled chemical bottle may contain a genie and not the expected reagent, according to a cautionary retraction that could be a warning for all bench researchers.

Sreenivasan Sasidharan, a researcher at the Institute for Research in Molecular Medicine (INFORMM), part of the Universiti Sains Malaysia, used a bottle labeled lantadene A, a liver-destroying chemical from the leaves of the Lantana camara plant that some livestock eat.

Sasidharan found that contrary to expectations, “lantadene A” protected livers against damage from acetaminophen — aka Tylenol.

But Manu Sharma, assistant pharmacy professor at Jaypee University of Information Technology in India, suspected something was technically amiss:

This claim that the authors were able to dissolve the non-polar pentacyclic triterpenoid lantadene A in water was quite surprising to me, as the Toxnet database reports the calculated solubility of lantadene A in water at 25 °C as just 7.68 × 10−5 mg/L [2], suggesting that lantadene A is essentially insoluble in water. The facile solubilization of lantadene A in water mentioned in this paper thus raises questions about the identity of the compound actually tested and therefore the whole study and its conclusions.

An anonymous reader shared Sharma’s concerns. Turns out that the “lantadene A” in the bottle, ordered from Chemtron in Malaysia, wasn’t the expected chemical and remains a mystery — in an echo of a retraction we covered two years ago in which a bottle labeled rhodium was actually full of palladium.

The retraction reads in full:

A recent Comment by M. Sharma published in the journal Molecules [1] raises issues with our previously published paper [2]. After reviewing its content, and although we respectfully stand by our experimental description whereby we were able to prepare stock and working solutions of the substance being tested, the arguments presented do raise concerns about the true identity of the compound actually used and hence the results and conclusions of our paper.

Unfortunately, since becoming aware of this, we have been unable to characterize the original sample, now used up, and we have been unable to obtain a verified equivalent one from the local commercial supplier we used. In light of these facts, since we can no longer associate with any confidence our experimental results with the compound lantadene A, we would like to withdraw our paper until such a time that we can obtain a new sample, check its identity and redo the work. As to the comments regarding erroneous citation of references, we feel that since the paper is to be removed from the scientific record, any additional corrections are unnecessary at this time. As corresponding author I take full responsibility for the omission of not checking the compound used in our experiments and any errors in its contents, and would like to offer my apologies on behalf of my co-authors to the readership of Molecules for any inconveniences caused by this omission

References

1. Sharma, M. Remarks on Sasidharan et al. “Evaluation of the Hepatoprotective Effects of Lantadene A, a Pentacyclic Triterpenoid of Lantana Plants Against Acetaminophen-induced Liver Damage”. Molecules 2012, 17, 13937–13947. Molecules 2013, 18, 3442–3444.

2. Grace-Lynn, C.; Chen, Y.; Latha, L.Y.; Kanwar, J.R.; Jothy, S.L.; Vijayarathna, S.; Sasidharan, S. Evaluation of the Hepatoprotective Effects of Lantadene A, a Pentacyclic Triterpenoid of Lantana Plants against Acetaminophen-induced Liver Damage. Molecules 2012, 17, 13937–13947.

Here are those “comments regarding erroneous citation of references” from Sharma that the authors didn’t feel the need to address:

Finally, there are a number of other statements made in the paper that cite references in error. For example, the authors wrote in last line of the Introduction: “Thus the current study was conducted to investigate how lantadene A is associated with hepatoprotection or hepatotoxicity as this compound is used in the development of drugs”, yet the reference cited to support this statement (reference number [1] in the paper) contains no such information supportive of this fact. Moreover, reference [23] in the paper, cited by the authors to explain the protocol for induction of hepatotoxicity by acetaminophen does not contain anything related to hepatotoxicity, as the topic of said reference is the characterization of the SOS regulon of Caulobacter crescentus, so it’s surprising to this author that Sasidharan et al. would have used this reference in relation to the hepatotoxicity induction protocol. Such carelessness in any research paper published in a peer reviewed journal is not acceptable.

We contacted the editor-in-chief of Molecules, Derek J. McPhee, and he illuminated the already thorough retraction:

Prof. Sasidharan was given time (several months in fact) to check the identity of the compound they had tested. But as stated in the retraction, they had used up all the original sample and were unable to procure a verifiable replacement sample from the small local chemicals supplier they had used. We do not publish “amendments”…but in this case without the identity of the compound tested, the biological data is essentially useless, hence the decision to retract the paper.

The “standing behind the data” statement in no way implies the compound is correct – what it means that the authors were able to prepare aqueous solutions of some compound they had purchased from a commercial supplier under the assumption it was lantadene A (but which almost certainly was not lantadene A) and they are confident that the biological activity measured for those solutions is correct, even though without the true identity of the compound this data it is of little use to the scientific community, hence the retraction.

The moral of the story is to not blindly trust labels on commercial chemical bottles or even better, to always apply the (former U.S. president Ronald) Reagan approach: ‘trust, but verify’.

We reached out to Sasidharan, and will let you know if he gets back to us.

About these ads

Written by trevorlstokes

April 15, 2013 at 1:00 pm

5 Responses

Subscribe to comments with RSS.

  1. Researcher working with a substance for which he has no idea of the physical properties. Mind boggling.

    Chip_MoMo (@Chip_Molly)

    April 15, 2013 at 4:51 pm

    • How many bioscience papers use chemicals on “trust”, including speciality chemicals? Most. How old is that bottle of Triton-X-100 on the shelf and how much peroxide has built up?

      ferniglab

      April 16, 2013 at 5:22 pm

  2. Trevor Stokes’ omission of part of my correspondence with him, leaving only the first part of a sentence (“We do not publish amendments…), may leave readers with the erroneous impression that a simple Correction was not an option in this case. It would obviously have been the logical choice if we had a compound identity to link the biological data to, but lacking the former, the latter could not stand on its own, hence the decision to withdraw the paper.

    Derek McPhee

    April 16, 2013 at 1:36 pm

  3. “The moral of the story is to not blindly trust labels on commercial chemical bottles or even better, to always apply the (former U.S. president Ronald) Reagan approach: ‘trust, but verify’.”
    The moral of the story is not to buy the story. Need to verify? Request to see the invoice. A company sells a bogus chemical that results in wasted time, resources, manpower, publication, reputation but no hell breaks loose?
    “As to the comments regarding erroneous citation of references, we feel that since the paper is to be removed from the scientific record, any additional corrections are unnecessary at this time.” – this deliberately misses the point. The authors derived their protocol from an irrelevant paper, it seems. Nobody expects a correction. But an explanation is necessary. Otherwise, the innuendo lingers.

    chirality

    April 16, 2013 at 4:19 pm

  4. That’s actually pretty scary. I joined a lab and was handed a falcon tube labeled ‘X’. I was doing chemical assays and the the chemical was not reacting as expected. Puzzled, I bought a vial of ‘X’ from Sigma. That sample of the chemical did react as expected.

    I left the lab ASAP.

    Neurospec

    April 29, 2013 at 12:01 am


We welcome comments. Please read our comments policy at http://retractionwatch.wordpress.com/the-retraction-watch-faq/ and leave your comment below.

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Follow

Get every new post delivered to your Inbox.

Join 35,800 other followers

%d bloggers like this: