Ingestion of Polyvinylchloride Powder Particles Induces Oxidative Stress and Hepatic Histopathological Changes in Oreochromis niloticus (Nile Tilapia)—A Preliminary Study

Round 1

Reviewer 1 Report

I revised the manuscript taking into account my comments and requests regarding the previous version of this manuscript. I consider that the authors responded to my comments and improved the manuscript sufficiently.

Author Response

Thank you

Reviewer 2 Report

Abstract: OK

Keywords: OK

Information should be given about how particles  to the feed must be more detailed.

Trial design' s information is poor.

There are more daily references about MP pollution on fish, please check them.

 

 

Author Response

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Reviewer 3 Report

This manuscript has not improved much since last submission. The discussion is not revised in a thorough manner and is still unappropriate for a scientific paper. I encourage the authors to once again look at my previous comments.

Author Response

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Reviewer 4 Report

Plastic pollution in the aquatic ecosystem has attained considerable interest in recent days and hence the present work is quite relevant. I have few observations regarding the manuscript mentioned below:

1.      Is Oreochromis niloticus susceptible to pollution by plastic of the size taken in this experiment? Comment on feeding habit of the model fish is essential to justify the choice.

2.      Was there any report regarding plastic accumulation in tilapia muscle that may also affect the consumers. This point must be mentioned.

3.      Was feeding the only entry route of PVC of the selected size in natural environment or these may also pass through the integument?

4.      Why juveniles were selected for the experiment?

5.      In each treatment group, was 10 fish kept in a single aquarium? What about the replication of the experiment?  

6.      How the fish were anaesthetised? How was liver tissue collected? Please provide details.

7.      ROS generation should have been measured.

Author Response

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Reviewer 5 Report

The article written by Abdulhusein Jawdhari et al., is interesting and topical. However, some criticisms are evident. In the writing of the article, some scientific names should be formatted in italics, English should be rechecked in grammar and spell. In addition, the conclusions are not supported by sufficient bibliographic data, especially in relation to histological evaluation. The authors use only H/E, which undoubtedly is the elective staining for an initial data. But later additional staining is needed to help highlighting different cell populations, such as immune cells, which should be the first to change especially in numbers. A staining such as GIEMSA would be indicated to assess the presence of mast cells and macrophages , for example. Also, staining such as Mallory or Masson, being trichrome staining, would give wider range of evaluation and make the results clearer. I would also suggest that the authors explain in more detail the statistical analysis they performed, also they could apply statistics on immune cells as well, to increase the quality of their work, and corroborate their data on induced liver alterations. Overall, the article still seems too preliminary, so I suggest that it should be further revised and implemented with the given suggestions.

Author Response

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Round 2

Reviewer 3 Report

I have made my case in previous reports

Author Response

Dear Reviewer #3,

Although we are aware that our manuscript does not cover the immunological aspects as you intended, please take into consideration the fact that an immunology study was not the purpose of this work. The presented manuscript is a preliminary study regarding microplastic toxicity in the specified size range. Even so, we acknowledge, agree and accept the importance of the topic you invoked, therefore we complied with your request by revising the discussion and by citing relevant articles [54-59] on the subject in question, as you requested.  

Thank you for the opportunity given to improve our manuscript.

Best regards,

The authors

References

54. Bjørgen, H.; Koppang, E.O. Anatomy of teleost fish immune structures and organs. Immunogenetics 2021, 73, 53-63, doi:10.1007/s00251-020-01196-0.

55. Hellberg, H.; Bjerkås, I.; Vågnes, Ø.B.; Noga, E.J. Mast cells in common wolffish Anarhichas lupus L.: Ontogeny, distribution and association with lymphatic vessels. Fish & Shellfish Immunology 2013, 35, 1769-1778, doi:10.1016/j.fsi.2013.08.031.

56. Roberts, R.J.; Young, H.; Milne, J.A. Studies on the skin of plaice (Pleuronectes platessa L.). Journal of Fish Biology 1972, 4, 87-98, doi:https://doi.org/10.1111/j.1095-8649.1972.tb05656.x.

57. A., S.; Brines, M.; Blank. The mast cell plays a central role in the immune system of teleost fish. Molecular immunology 2015, 63, doi:10.1016/j.molimm.2014.02.007.

58. Reite, O.B.; Evensen, Ø. Inflammatory cells of teleostean fish: A review focusing on mast cells/eosinophilic granule cells and rodlet cells. Fish & Shellfish Immunology 2006, 20, 192-208, doi:10.1016/j.fsi.2005.01.012.

59. Baccari, G.C.; Pinelli, C.; Santillo, A.; Minucci, S.; Rastogi, R.K. Mast Cells in Nonmammalian Vertebrates. International Review of Cell and Molecular Biology 2011, 1-53, doi:10.1016/b978-0-12-386037-8.00006-5.

Reviewer 4 Report

The authors have tried to answer the queries of the reviewers and the manuscript has improved considerably.

Author Response

Dear Reviewer #4, 

Thank you for your acceptance.

Cordially,

The authors

Reviewer 5 Report

The authors have improved the quality of the manuscript, following the requested suggestions as far as possible. Considering the article as a preliminary study, this can be accepted for publication in its present form.

Author Response

Dear Reviewer #5, 

Thank you for your acceptance.

Cordially,

The authors