PONE-D-24-16310Potential of methanol extracts of Nephelium lappaceum (Sapindaceae) and Hyphaene thebaica (Arecaceae) as adjuvants to enhance the efficacy of antibiotics against critical class priority bacteriaPLOS ONE

Dear Dr. Seukep,

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ACADEMIC EDITOR: Revision Requested

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Academic Editor

PLOS ONE

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Additional Editor Comments:

Major Revision Requested

Comments from the Editorial Team: One or more of the reviewers has recommended that you cite specific previously published works. Members of the editorial team have determined that the works referenced are not directly related to the submitted manuscript. As such, please note that it is not necessary or expected to cite the works requested by the reviewer.

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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: Yes

Reviewer #2: Yes

Reviewer #3: Yes

Reviewer #4: Partly

Reviewer #5: No

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

Reviewer #1: I Don't Know

Reviewer #2: Yes

Reviewer #3: Yes

Reviewer #4: No

Reviewer #5: Yes

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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: No

Reviewer #2: Yes

Reviewer #3: Yes

Reviewer #4: Yes

Reviewer #5: Yes

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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: Yes

Reviewer #3: Yes

Reviewer #4: Yes

Reviewer #5: 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: Methodology:

"All bacterial isolates were cultured on Mueller Hinton agar (MHA) (Liofilchem S.r.l., Italy) and

the microdilution testing was done using Mueller Hinton broth (MHB) (Titan Biotech Ltd.,

India) to determine the test samples' minimum inhibitory concentration (MIC), minimum

bactericidal concentration (MBC), and activity increase factor (AIF) (following combination

assays)."

Q: The combination assay should be elaborated in the methodology section.

Results:

Table 1- Why MBC values are not stated for all the tested microorganism?Hence it has resulted in not have the MBC/MIC ratio values for respective bacterial isolates.

Why only one Antibiotic (Imipenem) has been used as reference antibiotic for all the tested microorganism? Explain this.

Combination Testing result should be provided as part of the results and not as Supplemental information 2 and 3.

Reviewer #2: The authors have examined the efficacy of methanolic extracts from two food plants (Nephelium lappaceum and Hyphaene thebaica), alone and in combination with antibiotics, against normal and resistant bacteria strains. Below are some comments

Result section :

• The authors do not indicate the MIC unit of the reference antibiotic (Imipenem). Is it also in (μg/mL)?

• It would be possible to use the most recent MIC classification scales, which reflect the current level of bacterial virulence in clinical practice.

• The figures shown are not numbered.

• The first figure is not numbered on the x-axis.

Reviewer #3: This work reports the Potential of methanol extracts of Nephelium lappaceum (Sapindaceae) and Hyphaene thebaica (Arecaceae) as adjuvants to enhance the efficacy of antibiotics against critical class priority bacteria

The work is meaningful and interesting.

In the "Introduction" or "Experimental Section", the authors need to provide or add a more detailed explanation about exploring the antibacterial activity of plants which in this study was used to methanol extracts. Here are some papers that can be used by the authors to find out more about antibacterial activity of plants and need to be added and cited by the authors in this manuscript:

doi: 10.1016/j.sjbs.2021.10.057

doi: 10.1155/2021/6663399

doi: 10.1038/s41598-023-32900-1

Reviewer #4: The current Manuscript Number: PONE-D-24-16310; entitled:Manuscript Title: Potential of methanol extracts of Nephelium lappaceum (Sapindaceae) and Hyphaene thebaica (Arecaceae) as adjuvants to enhance the efficacy of antibiotics against critical class priority bacteria

The current manuscript contained a good idea and i have the following comments:

- Please add statistical analysis in methods section and explain the significance along the whole manuscript.

- It essential to identify the bioactive compounds of extracts using one of the chromatographic analysis e.g : Gad chromatography and link the antimicrobial activity to these compounds.

- I highly recommend to examine antioxidant actions of extracts and compare all of them.

- Please rewrite the manuscript sections after the adding the suggesting experiments and statistics.

Reviewer #5: 1. Why do various portions of Nephelium lappaceum and Hyphaene thebaica have distinct antibacterial effects against multidrug-resistant bacteria?

2. What caused Nephelium lappaceum leaf extract to have the greatest antibacterial activity against all multidrug-resistant strains? What are its mechanisms?

3. What causes the extracts' MIC and MBC values to vary for various bacterial strains?

4. Given the synergy between plant extracts and antibiotics, how can Nephelium lappaceum and Hyphaene thebaica extracts boost antibiotic efficacy?

5. What does the MBC/MIC ratio of < 4 indicate for most extracts, and how does it affect their bactericidal vs bacteriostatic properties?

6. How does Nephelium lappaceum leaf extract's capacity to lower pH by inhibiting H⁺-ATPase relate to its antibacterial effectiveness?

7. How can certain secondary metabolites (saponins, phenols, tannins, steroids, alkaloids) affect the antibacterial activity of plant extracts, and how could their presence or absence affect results?

8. What does the absence of antagonistic interactions between plant extracts and antibiotics mean for future combination treatment methods for multidrug-resistant bacterial infections?

9. How do Nephelium lappaceum and Hyphaene thebaica phytochemical profiles and extraction yields differ, and how could they affect their antibacterial applications?

10. What further study is required to understand the cellular and molecular mechanisms of Nephelium lappaceum and Hyphaene thebaica extracts' antibacterial properties, especially their impact on bacterial cell membranes and metabolic processes?

11. The author needs to provide GC-MS data of the active molecules present in the extracts.

12. It is essential to compare the biological activity of the extract with that of the pure compound identified through GC-MS analysis. This comparison will add novelty to the study; otherwise, using extracts alone lacks significance, as there are already numerous studies (more than 1000 publications) focused on extract-based biological activities.

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Reviewer #1: No

Reviewer #2: No

Reviewer #3: No

Reviewer #4: Yes: Mohammed Yosri

Reviewer #5: No

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Attachments

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Submitted filename: Review comment MF.docx

Potential of methanol extracts of Nephelium lappaceum (Sapindaceae) and Hyphaene thebaica (Arecaceae) as adjuvants to enhance the efficacy of antibiotics against critical class priority bacteria

PONE-D-24-16310R1

Dear Dr. Seukep,

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.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

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Kind regards,

Divakar Sharma

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Accept

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 #3: All comments have been addressed

Reviewer #4: All comments have been addressed

Reviewer #5: 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 #3: Yes

Reviewer #4: Partly

Reviewer #5: Yes

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

Reviewer #3: Yes

Reviewer #4: Yes

Reviewer #5: 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 #3: Yes

Reviewer #4: Yes

Reviewer #5: 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 #3: Yes

Reviewer #4: Yes

Reviewer #5: 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 #3: The manuscript has modified well by the authors and the scientific level of the manuscript is acceptable for publication.

Reviewer #4: Manuscript Number PONE-D-24-16310R1; entitled Potential of methanol extracts of Nephelium lappaceum (Sapindaceae) and Hyphaene thebaica (Arecaceae) as adjuvants to enhance the efficacy of antibiotics against critical class priority bacteria

The manuscript has improved to some extent and it could be accepted for publication.

Reviewer #5: The author addressed all questions. No further revisions needed. I recommend acceptance of this paper.

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7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

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 #3: No

Reviewer #4: Yes: Mohammed Yosri

Reviewer #5: No

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