GC/MS Profiling, In Vitro Antidiabetic Efficacy of Origanum compactum Benth. Essential Oil and In Silico Molecular Docking of Its Major Bioactive Compounds

Round 1

Reviewer 1 Report (Previous Reviewer 1)

Within the introduction, the authors should should cite the following manuscript:https://www.degruyter.com/document/doi/10.1515/chem-2022-0282/html?lang=en. While also add relevant information as to how its different to the current manuscript. Importantly, both the abstract and conclusion sections should clearly highlight the limitations of the current report, especially the lack of using relevant models (in vivo) to assess/confirm the anti-diabetic efficacy of investigated extracts

The authors have already reported on the effect of “Essential oils of Origanum compactum Benth: Chemical characterization, in vitro, in silico, antioxidant, and antibacterial activities” in published work: https://www.degruyter.com/document/doi/10.1515/chem-2022-0282/html?lang=en. The current reports build on that literature but now focuses on the Origanum compactum Benth., oil and their major compounds, but also uniquely investigates its in vitro anti-diabetic efficacy.

Although the current report is unique for focusing on the major compounds of Origanum compactum Benth., oil and their potential antidiabetic properties, the authors should clearly highlight/cite within the report (especially within the introduction) other work that has been done on these oils:

https://www.degruyter.com/document/doi/10.1515/chem-2022-0282/html?lang=en

https://www.sciencedirect.com/science/article/pii/S0254629917311535

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6951490/

Advantages and strong motivation should be give for making use of Molecular docking study. Motivation of the current methodology should be given, for in vitro assays as well. In fact, the manuscript should contain a section on strengths and weaknesses of the current work/methodology. This should be able to guide future research.

The authors mention “Overall, this information could be useful in the context of diabetes management.” But this is a vague statement and should be amended, or rather “Such findings open avenues for future research to investigate these oils and its major bioactive compounds for their potential antidiabetic properties”

Recent work on the therapeutic of this plant/oils, including its bioactive compounds should be added.

Author Response

To Editor of

Catalysts

Re: Revision of Manuscript number: Catalysts-2631303

Dear Editor,

First and foremost, we wish to thank you for granting us the opportunity to improve our manuscript entitled “   GC/MS Profiling, In vitro antidiabetic efficacy of Origanum compactum Benth., essential oil and in silico molecular docking of its major bioactive compounds ” submitted to Catalysts, which we believe will benefit readers of your high-quality journal.

We appreciate the time and effort that you have dedicated to provide your valuable feedback on our paper. We are very grateful to you and to the reviewer for the insightful comments and the high quality and constructive reviews of our manuscript. It is our belief that the manuscript is substantially improved after making the suggested edit.

In this revised version, we did our best to address all comment raised by the editor and the reviewers.

Please find below our point-by-point response to reviewers’ comments.

Please note that to facilitate tracking, the changes made in light of reviewers’ comments have been highlighted in yellow.

We look forward to your positive response.

Thank you for your attention.

Yours sincerely,

Pr. Naoufal El Hachlafi

Comments from the Editors and Reviewers:

Reviewer #1:

Comment 1:

Within the introduction, the authors should should cite the following manuscript:https://www.degruyter.com/document/doi/10.1515/chem-2022-0282/html?lang=en. While also add relevant information as to how its different to the current manuscript. Importantly, both the abstract and conclusion sections should clearly highlight the limitations of the current report, especially the lack of using relevant models (in vivo) to assess/confirm the anti-diabetic efficacy of investigated extracts.

Author response

Thank you for your thorough review and bringing these issues to our attention. In response to your suggestion, we have made the necessary revisions by adding the suggested reference as well as adding relevant information as to how its different to the current manuscript.

Please see below and in introduction section:

El Abdali et al. [24] have already demonstrated the antimicrobial and antioxidant potential of O. compactum EOs through in vitro and in silico approaches. However, there is no published work about the antidiabetic properties of this oil. Indeed, this exploratory investigation is the first to determine the antidiabetic activity of this oil through in vitro and in silico analysis.      

Moreover, we have highlithed in the conclusion section and abstract the limitation of this study, pleasse see below :

However, further in vivo investigations are strongly required to confirm the results of in vitro antidiabetic effect of O. compactum EO.

Comment 2:
The authors have already reported on the effect of “Essential oils of Origanum compactum Benth: Chemical characterization, in vitro, in silico, antioxidant, and antibacterial activities” in published work: https://www.degruyter.com/document/doi/10.1515/chem-2022-0282/html?lang=en. The current reports build on that literature but now focuses on the Origanum compactum Benth., oil and their major compounds, but also uniquely investigates its in vitro anti-diabetic efficacy.

Author response

Thank you for your thorough review and valuable feedback. We have added the relevant information in the introduction section.

Comment 3:

Although the current report is unique for focusing on the major compounds of Origanum compactum Benth., oil and their potential antidiabetic properties, the authors should clearly highlight/cite within the report (especially within the introduction) other work that has been done on these oils:

https://www.degruyter.com/document/doi/10.1515/chem-2022-0282/html?lang=en

https://www.sciencedirect.com/science/article/pii/S0254629917311535

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6951490/

Author response

Thank you so much for mentioning this important point, we agree with you and we have added studies on the therapeutic of this plant/oils (taken in account the suggested references), including its bioactive compounds in the introduction section according to your kind suggestion.

Please see below:

Recent investigations have showed that O. compactum EOs possess promising health bene-fits and biological properties, including antioxidant, anticancer, insecticidal and anti-inflammatory activities. Moreover, O. compactum EOs have also found to exhibit interesting antimicrobial effects against yeast, molds, Gram-positive and Gram-negative bacteria [21]. El Abdali et al. [24] have already demonstrated the antimicrobial and antioxidant potential of O. compactum EOs through in vitro and in silico approaches. However, there is no published work about the antidiabetic properties of this oil. Indeed, this exploratory investigation is the first to determine the antidiabetic activity of this oil through in vitro and in silico analysis.       

The unique bioactive compounds present in O. compactum oil make it an intriguing subject for further investigation, particularly regarding its anti-diabetic mechanisms and potential therapeutic applications. O. compactum oil is generally rich in oxygenated mono-terpenes such as thymol and carvacrol, which are known by their broad bioactivities [25–27]. They possess valuable antimicrobial, antioxidant, antidiabetic, anti-inflammatory, anticancer and insecticidal activities [28,29].  

Comment 4:

Advantages and strong motivation should be give for making use of Molecular docking study. Motivation of the current methodology should be given, for in vitro assays as well. In fact, the manuscript should contain a section on strengths and weaknesses of the current work/methodology. This should be able to guide future research.

Author response

Thank you for mentioning this important point, we have added a section on strengths and weaknesses of the current work as per of your suggestion.

Please see below.

3.7 Strengths and weaknesses of methodology

These study sustaining the translational potential of O. compactum EO for the diabetes mellitus treatment, provided a coherent justification for further in vivo studies on the modulation of the activities of ɑ-glucosidase and ɑ-amylase by the oregano oil constituents. However, it would be beneficial to test the in vitro antidiabetic activities of single compounds of this oil to clearly elucidate their antidiabetic efficacy.

The original algorithm used in the present manuscript that applied various software techniques to predict some physio-chemical, toxicological and biological properties and moreover, highlighted the inners mechanisms involved in the induction of these characters, may represent a useful evaluation tool to be tested before in vivo evaluations of other natural products with biological activity. However, further in silico investigations targeting all O. compactum EO are strongly required to enhance knowledge gaps in the antidiabetic potential of this oil.

Comment 5:

The authors mention “Overall, this information could be useful in the context of diabetes management.” But this is a vague statement and should be amended, or rather “Such findings open avenues for future research to investigate these oils and its major bioactive compounds for their potential antidiabetic properties”

Author response

Thank you for this interesting remark, accordingly we have used the suggested sentence instead “Overall, this information could be useful in the context of diabetes management in the conclusion section.

Comment 6:

Recent work on the therapeutic of this plant/oils, including its bioactive compounds should be added.

Author response

Thank you so much for mentioning this important point, we agree with you and we have added recent studies on the therapeutic of this plant/oils, including its bioactive compounds in the introduction section according to your kind suggestion.

Please see below:

Recent investigations have showed that O. compactum EOs possess promising health bene-fits and biological properties, including antioxidant, anticancer, insecticidal and anti-inflammatory activities. Moreover, O. compactum EOs have also found to exhibit interesting antimicrobial effects against yeast, molds, Gram-positive and Gram-negative bacteria [21]. El Abdali et al. [24] have already demonstrated the antimicrobial and antioxidant potential of O. compactum EOs through in vitro and in silico approaches. However, there is no published work about the antidiabetic properties of this oil. Indeed, this exploratory investigation is the first to determine the antidiabetic activity of this oil through in vitro and in silico analysis.       

The unique bioactive compounds present in O. compactum oil make it an intriguing subject for further investigation, particularly regarding its anti-diabetic mechanisms and potential therapeutic applications. O. compactum oil is generally rich in oxygenated mono-terpenes such as thymol and carvacrol, which are known by their broad bioactivities [25–27]. They possess valuable antimicrobial, antioxidant, antidiabetic, anti-inflammatory, anticancer and insecticidal activities [28,29].  

Once again, we express our gratitude for your expert opinion and the constructive feedback, which has highlighted areas for improvement in our manuscript. We are working diligently to address these issues and strive to produce a high-quality paper that adds value to the field of pharmacological research. Your guidance and expertise are highly appreciated, and we are committed to enhancing the overall quality and impact of our research.

Author Response File: Author Response.pdf

Reviewer 2 Report (New Reviewer)

Several edits have been made to the revised manuscript accordingly. One issue that needs attention is the presentation of words in Tables 3 and 4: it should be organized more clearly for better readability.

Author Response

Reviewer #2:

Several edits have been made to the revised manuscript accordingly. One issue that needs attention is the presentation of words in Tables 3 and 4: it should be organized more clearly for better readability.

Author response

Thank you for pointing this out, we agree with you and accordingly we have organized the words in tables 3 and 4 for better readability.

Author Response File: Author Response.pdf

Reviewer 3 Report (New Reviewer)

The present manuscript aimed to evaluate the translational potential of O. compactum oil  for the diabetes mellitus treatment, by testing the modulation of the activities of human ɑ-glucosidase and ɑ-amylase. Practically, in vitro inhibition effects of the activities of human α-amylase  and α-glucosidase by the Origanum oil were evaluated. Moreover, the modulation of the action mechanism was tested and explained based on the results of a molecular software study considering 2D- and 3D- interactions of the strongest (ligand-protein) complexes formed between  either α-amylase , α-glucosidase and NADPH oxidase with the main Origanum (compactum Benth) oil components.

Strong points:

·         these original results sustaining the translational potential of O. compactum oil  for the diabetes mellitus treatment, provided a coherent justification for further in vivo studies on the modulation of the activities of ɑ-glucosidase and ɑ-amylase by the Origanum oil constituents.

·         the original algorithm used in the present manuscript that applied variouse software techniques to predict some physio-chemical, toxicological and biological properties and moreover, highlighted the inners mechanisms involved in the induction of these characterics, may represent an usefull evaluation tool to be tested before in vivo evaluations of other natural products with biological activity.

Weak points:

1-      Section 2.5.) ADMET prediction it is insufficiently explained in terms of the methodology. Morover, the toxicity prediction discussed together  with ADMET  results in the section 3.3. is not at all mentioned in  the Materials and Methods section. Thus, the relevance of applying this (ADMET & toxicity) method of prediction of pharmacodynamic and toxicological characteristics of a natural compound, it’s not clear.

2-      Section 3.3) Title of the  table 3 (and table 4)  is announcing 12 compounds, but in the table 3 and 4 are presented only  4 compounds (C1-C4) which are not at all identified, either in the text of the section 3.3 (or before3.3.) or in the legends of the tables 3 & 4. Moreover, the comments from section 3.3  contain  too many forced statements that are not explained and have no reference links to the bibliography.

3-      Figure 1 and 2 presents results for the compounds C1-C4 which are not at all  identified.

4-      In the section 3.4. Molecular docking, Carvacrol (C2), and Thymol (C3) are identified in the first paragraphs, but in the figures Nb. 3 (and Nb. 4), Thymol appears as (C15) .

Considering  all the above reasons I recommend to reconsider after major revision  the manuscript that requires extensive attention to the logic of the presentation to avoid inconsistencies between the comments and the details presented in the text, tables and figures of the manuscript. 

Moderate editing of English language required

Author Response

To Editor of

Catalysts

Re: Revision of Manuscript number: Catalysts-2631303

Dear Editor,

First and foremost, we wish to thank you for granting us the opportunity to improve our manuscript entitled “   GC/MS Profiling, In vitro antidiabetic efficacy of Origanum compactum Benth., essential oil and in silico molecular docking of its major bioactive compounds ” submitted to Catalysts, which we believe will benefit readers of your high-quality journal.

We appreciate the time and effort that you have dedicated to provide your valuable feedback on our paper. We are very grateful to you and to the reviewer for the insightful comments and the high quality and constructive reviews of our manuscript. It is our belief that the manuscript is substantially improved after making the suggested edit.

In this revised version, we did our best to address all comment raised by the editor and the reviewers.

Please find below our point-by-point response to reviewers’ comments.

Please note that to facilitate tracking, the changes made in light of reviewers’ comments have been highlighted in yellow.

We look forward to your positive response.

Thank you for your attention.

Yours sincerely,

Pr. Naoufal El Hachlafi

Comments from the Editors and Reviewers:

Reviewer #3

  The present manuscript aimed to evaluate the translational potential of O. compactum oil  for the diabetes mellitus treatment, by testing the modulation of the activities of human ɑ-glucosidase and ɑ-amylase. Practically, in vitro inhibition effects of the activities of human α-amylase  and α-glucosidase by the Origanum oil were evaluated. Moreover, the modulation of the action mechanism was tested and explained based on the results of a molecular software study considering 2D- and 3D- interactions of the strongest (ligand-protein) complexes formed between  either α-amylase , α-glucosidase and NADPH oxidase with the main Origanum (compactum Benth) oil components.

Strong points:

these original results sustaining the translational potential of O. compactum oil  for the diabetes mellitus treatment, provided a coherent justification for further in vivo studies on the modulation of the activities of ɑ-glucosidase and ɑ-amylase by the Origanum oil constituents.

 the original algorithm used in the present manuscript that applied variouse software techniques to predict some physio-chemical, toxicological and biological properties and moreover, highlighted the inners mechanisms involved in the induction of these characterics, may represent an usefull evaluation tool to be tested before in vivo evaluations of other natural products with biological activity.

Author response

Thank you for your constructive review and positive feedback.

Weak points:

• Section 2.5.) ADMET prediction it is insufficiently explained in terms of the methodology. Morover, the toxicity prediction discussed together with ADMET results in the section 3.3. is not at all mentioned in the Materials and Methods section. Thus, the relevance of applying this (ADMET & toxicity) method of prediction of pharmacodynamic and toxicological characteristics of a natural compound, it’s not clear.

Author response

Thank you for your feedback on the ADMET prediction in Section 3.5 and the lack of explanation regarding the methodology. We acknowledge the concerns you raised regarding the absence of information about toxicity prediction in the Materials and Methods section. Consequently, we have added more explanation to the results section  2.3. Additionally, we have updated the Materials and Methods section to include a description of the toxicity prediction method (title 3.5).

Thank you for your attention to detail and constructive criticism.

• Section 3.3) Title of the table 3 (and table 4)  is announcing 12 compounds, but in the table 3 and 4 are presented only  4 compounds (C1-C4) which are not at all identified, either in the text of the section 3.3 (or before3.3.) or in the legends of the tables 3 & 4. Moreover, the comments from section 3.3  contain  too many forced statements that are not explained and have no reference links to the bibliography.

Author response

Thank you for pointing this out, in this investigation we have only focused on the four major components identified in O. compactum EO (among 12 identified components).

Moreover, in response to your suggestion, we have made the necessary revisions to the manuscript to include a clear and detailed explanation with relevant bibliography in the mentioned section: 2.3. ADME and toxicity prediction in results section.

3-      Figure 1 and 2 presents results for the compounds C1-C4 which are not at all  identified.

Author response

Thank you for pointing this out, in this investigation we have only focused on the four major components identified in O. compactum EO (among 12 identified components).

4-      In the section 3.4. Molecular docking, Carvacrol (C2), and Thymol (C3) are identified in the first paragraphs, but in the figures Nb. 3 (and Nb. 4), Thymol appears as (C15) .

Author response

You are absolutely right, and we appreciate your attention to detail. In response to your suggestion, we have corrected all these issues  (Thymol (C3)) in text, in figure 3 and 4 and in table.

Considering  all the above reasons I recommend to reconsider after major revision  the manuscript that requires extensive attention to the logic of the presentation to avoid inconsistencies between the comments and the details presented in the text, tables and figures of the manuscript.

Once again, we express our gratitude for your expert opinion and the constructive feedback, which has highlighted areas for improvement in our manuscript. We are working diligently to address these issues and strive to produce a high-quality paper that adds value to the field of pharmacological research. Your guidance and expertise are highly appreciated, and we are committed to enhancing the overall quality and impact of our research.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report (Previous Reviewer 1)

The authors have successfully addressed all my comments.

Reviewer 3 Report (New Reviewer)

The manuscript has been sufficiently improved to warrant  publication in Catalysts.

The manuscript has been sufficiently improved to warrant  publication in Catalysts.

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

The authors evaluated in vitro anti-diabetic efficacy of Origanum com-pactum Benth., oil, while performing an in-silico investigation to ascertain how it binds to human enzymes. The novelty of the study is compromised by an already published report on “Essential oils of Origanum compactum Benth: Chemical characterization, in vitro, in silico, antioxidant, and antibacterial activities” https://www.degruyter.com/document/doi/10.1515/chem-2022-0282/html?lang=en

The only results that show potential novelty are those of in vitro antidiabetic properties, however even to prove that (to provide a comprehensive understanding of the topic) the authors should perform assays using relevant cell lines or animals with diabetes, which could significantly increase the value of the current study.

Reviewer 2 Report

The article is devoted to the study of in vitro the effects of Origanum oil components compactum Benth on alpha activity - amylases and alpha - glucosidases and determination of their inhibition mechanism in in silico research. Work is of scientific and practical interest.

Authors used modern research methods. However, shortcomings should be noted ,which require adjustment:

1- the article does not indicate the source of receipt enzymes for research in vitro.

2-title of the article does not match the content of the work. The work studied the action of thymol, carvacrol and cymola on the activity of in vitro and in silico enzymes, not their antidiabetic action.

Inhibition of alpha glucosidase can lead to anti-diabetic effect, but this effect must be confirmed in studies in vivo, not in vitro.