PONE-D-21-39473MAJOR CHEMICAL CARCINOGENS AND HEALTH EXPOSURE RISK IN SOME THERAPEUTIC HERBAL PLANTS IN NIGERIAPLOS ONE

Dear Dr. Njinga,

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Noshin Ilyas

Academic Editor

PLOS ONE

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Additional Editor Comments:

This paper needs comprehensive revisions, more details are required about collected samples, statistical analysis and work. Moreover, authors should add recent literature in introduction and discussion.

Reviewers' comments should also be properly addressed

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Partly

Reviewer #2: Partly

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2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: No

Reviewer #2: No

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3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: No

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4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: No

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5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: The manuscript entitled "MAJOR CHEMICAL CARCINOGENS AND HEALTH EXPOSURE RISK IN SOME

THERAPEUTIC HERBAL PLANTS IN NIGERIA" can be accepted with major revisions.

Methodology and result section is poorly written in non-technical way.

Results in table 2 reveal that, the amount of Cd in C. guajava collected from Kanu, and Jigwa was .037 and .05 mg/ kg which was little bit higher than WHO standards (.02 mg/kg); further its significance should be tested with z-test. On the other hand the Cr as depicted in table 2, is in safe-limits (less than 1.3 mg/kg); its significance can also be test by z-test.

In table 3, the EDI is also within the acceptable limits, so what is the author claiming for?

Further more, I would like to recommend some statistical analyses to make the manuscript findings better understandable.

There would be analysis of variance (ANOVA) using two factors (Locations and Plant-species) using HSD as post-hoc for each studied variable.

Strictly, there would be a z-test for EDI, THQ, HI, TCR in which author should compare the observed average values with standard acceptable values; the results would be presented in the form of z-values, and p-values for each variable. Without the z-test, the findings and claim of the author is NOT reliable.

Quality of graphs (data visualization) is poor can be made better by highlighting (horizontal line at y-axis parallel to x-axis) the acceptable ranges in each graph

Reviewer #2: Dear Authors,

The article, “MAJOR CHEMICAL CARCINOGENS AND HEALTH EXPOSURE RISK IN SOME THERAPEUTIC HERBAL PLANTS IN NIGERIA” highlights the issue contamination in herbal remedies. The heavy metals (Cd and Cr) are the major toxicants in plants (Herbs or Vegetables), and these metals are sourced from irrigation water or the polluted soil. However, as I reviewer I have some comments that need to be addressed before reaching any final decision.

First the abstract has to be revised thoroughly, the second sentence starting “Accumulation of MCCs….” Is confusing and need to be revised. I am wondering how the authors named heavy metals (Cd and Cr) as MCC?? Abstract has many typos, difficult to highlight each one here. It’s not clear which plant has higher concentration of these metals?

Why the authors have not considered investigating several other heavy metals? I wonder if the authors have also studied the nutritionally important metals in these plants?

The introduction part is weak, it needs improvement in terms of detailed information of C. papaya, P. guajava, and A. digitate. The introduction section just lists the review of literature it lacks the real on-ground information, socio-economic value of these plants? Also, It will be good to have pictures of these plants and the plant distribution in Nigeria, etc.

The presented data lack the proper statistical analysis. As per my understanding, the plant samples were collected from different locations in Nigeria, hence it will be best to point to these localities with a higher concentration of heavy metals in samples. This information will be good for the folks and herbalists to refrain to use these plants in their formulations.

The number of samples per plant sample is low I just wonder if the toxic metals are really sourced from plants or in solvents?? Did the Authors try to analyze these metals in the solvents?

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Reviewer #1: No

Reviewer #2: No

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PONE-D-21-39473R1MAJOR CHEMICAL CARCINOGENS AND HEALTH EXPOSURE RISK IN SOME THERAPEUTIC HERBAL PLANTS IN NIGERIAPLOS ONE

Dear Dr. Njinga,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

Please see the reviewers' comments below. Please note that if a reviewer has requested citations to specific articles, those articles should only be cited if they are directly relevant to the study. If you find that any number of the requested citations are irrelevant or inappropriate, please state this in your Response to Reviewers for each article you assess to be irrelevant or inappropriate to cite.

In addition, we ask you to respond fully to the following editorial matters. Please note that further consideration of your manuscript is contingent on satisfying these requirements:

1) Thank you for your response stating "We have cited the expert with similar medicinal plants in their articles." However, this does not address our request regarding how the samples used in this study were reliably identified. Please provide in your manuscript text the name of the expert consulted in identifying the samples, or otherwise please provide detailed information regarding how the samples were definitively identified.

2) Thank you for your response stating "No permit is needed since this is an individual research work and might be used by the government as baseline data." However, this does not address our request regarding permits obtained for the work. Specifically, we ask you to clarify in your manuscript text whether any permits (such as for site access) were obtained for the field work in gathering the samples used in this study. If no permits were required, please instead include in your manuscript text a brief statement explaining why.

3) During our internal evaluation of the manuscript, we found significant text overlap between your submission and the following previously published works:

"Vegetables contamination by heavy metals and associated health risk to the population in Koka area of central Ethiopia" (https://doi.org/10.1371/journal.pone.0254236)

We would like to make you aware that copying extracts from previous publications, especially outside the methods section, word-for-word is unacceptable. In addition, the reproduction of text from published reports has implications for the copyright that may apply to the publications.

Please revise the manuscript to rephrase the duplicated text, cite your sources, and provide details as to how the current manuscript advances on previous work. Please note that further consideration is dependent on the submission of a manuscript that addresses these concerns about the overlap in text with published work.

We will carefully review your manuscript upon resubmission, so please ensure that your revision is thorough.

Please submit your revised manuscript by Sep 25 2022 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

• A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.
• A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.
• An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols.

We look forward to receiving your revised manuscript.

Kind regards,

Hugh Cowley

Staff Editor

PLOS ONE

Journal Requirements:

Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice.

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: All comments have been addressed

Reviewer #3: All comments have been addressed

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2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #3: Yes

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3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #3: Yes

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4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #3: Yes

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5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #3: Yes

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6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: This is an interesting study and the authors have collected a unique dataset using cutting edge methodology. The paper is generally well written and structured

Reviewer #3: The revised paper can be accepted after Minor revision as suggested below

1) Statistical analysis details to be mentioned as footnote in each table

2) Some of the following recent and relevant publications can be cited. Its only suggestion.

Sustainability, 2021, 13, 8471. https://doi.org/10.3390/su13158471

International J of cancer management, 2021, 14(2):e89116 doi:10.5812/ijcm.89116

https://link.springer.com/chapter/10.1007/978-981-10-8548-2_19

Plos One, 2022, 17(4): e0266676. https://doi.org/10.1371/journal.pone.0266676

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If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #3: Yes: R.Z. Sayyed

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MAJOR CHEMICAL CARCINOGENS AND HEALTH EXPOSURE RISKS IN SOME THERAPEUTIC HERBAL PLANTS IN NIGERIA

PONE-D-21-39473R2

Dear Dr. Njinga,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

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Kind regards,

Hugh Cowley

Staff Editor

PLOS ONE

Additional Editor Comments (optional):

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