Effect of Sun Drying on Phytoconstituents and Antiviral Activity of Ginger against Low-Pathogenic Human Coronavirus

Round 1

Reviewer 1 Report

Effect of Sun Drying on Phytoconstituents and Antiviral Activity of Ginger Against Low-Pathogenic Human Coronavirus

 

 

This paper aims to assess the effect of sun drying on the volatile constituents, total

phenolics, and total flavonoid content, as well as demonstrate how the drying process affected the in-vitro antiviral activity of ginger against virus infections. Molecular docking and chemometrics studies were also applied as a multivariate tool to find similarities and differences between fresh and dry ginger and determine the relationship between the volatile compounds and the antiviral activity.

 

Line 62-63: “SARS-CoV-2, or COVID-19, is a main health hazard to the world.” In my opinion, this sentence is not completely accurate. It should be rephrased.

 

Line 63: Please rephrase to “… caused a worldwide pandemic.”

 

Line 67: “Natural-derived compounds are increasingly becoming a viable therapeutic option for various disorders, including viral infection.” Does it not always been? Traditional medicine proves it. I think the authors mean that this type of research is increasing. Please rephrase.

 

Please avoid spacing between results such as: 1.51 ± 0.244 in line 82, or 15.06 % in line 94. It should be 1.51±0.244 and 15.06%. Please also add a space before the units (mg) in “24.63±0.43 mg” in line 113.

 

Figure S1 should, at least, include the identification of the main compounds found.

 

Please explain what the initials TIC, TPC, TFC, … stand for, the first time you name them.

 

Tables 2 and 3: Please note that the results are not presented properly. The error or standard deviation should be presented with only 1 significant number, and the result in accordance. For instance: 39.33±2.57 should be 39±3 and 28.5±0.89 should be 28.5±0.9.

 

Please correct “ml” to “mL”.

 

Line 247: Please correct “(Figure. 2b)” to “Figure. 2b”.

 

Section 3 is missing. Was it the conclusion section? Because it is also missing.

 

Please add a small description for all the assays used (TPC, TFC…). Do not just write a sentence and add a reference.

Author Response

The authors would like to thank you for your interesting and valuable comments which have been covered as follows:

Point 1: SARS-CoV-2, or COVID-19, is a main health hazard to the world.

Respond 1: We agree that COVID -19 is one of the major challenge in the world and that is why it got our interest to work on it. Line 70

Point 2: Line 63: Please rephrase to “… caused a worldwide pandemic.”

Respond 2: Corrected as required in line 72

Point 3: “Natural-derived compounds are increasingly becoming a viable therapeutic option for various disorders, including viral infection.” Does it not always been? Traditional medicine proves it. I think the authors mean that this type of research is increasing. Please rephrase.

Respond 3: Natural products have traditionally played an important role in the process of the drug discovery for the management of many diseases. Therefore, and after the pandemic of COVID-19 in 2020 it was very interesting to screen one of the famous food and medicinal plant for combating of the viral infections. Line 62

Point 4: Please avoid spacing between results such as: 1.51 ± 0.244 in line 82, or 15.06 % in line 94. It should be 1.51±0.244 and 15.06%. Please also add a space before the units (mg) in “24.63±0.43 mg” in line 113.

Respond 4: Done as required. Line 198

Point 5: Figure S1 should, at least, include the identification of the main compounds found.

Respond 5: Done as required.

Point 6: Please explain what the initials TIC, TPC, TFC, … stand for, the first time you name them

Respond 6: Corrected as required. Line 188 and 215

Point 7: Tables 2 and 3: Please note that the results are not presented properly. The error or standard deviation should be presented with only 1 significant number, and the result in accordance. For instance: 39.33±2.57 should be 39±3 and 28.5±0.89 should be 28.5±0.9.

Respond 7: Corrected as required.

Point 8: Please correct “ml” to “mL”.

Respond 8: Corrected as required.

Point 9: Line 247: Please correct “(Figure. 2b)” to “Figure. 2b”.

Respond 9: Corrected as required to Figure 3a and Figure 3b line 346

Point 10: Section 3 is missing. Was it the conclusion section? Because it is also missing.

Respond 10: results and discussion are together as in

Integrated Management of Wild Oat (Avena fatua) and Feather Fingergrass (Chloris virgata) Using Simulated Grazing and Herbicides

Agronomy 2022, 12(10), 2586; https://doi.org/10.3390/agronomy12102586

Conclusion is added to the manuscript. Line 372

Point 11: Please add a small description for all the assays used (TPC, TFC…). Do not just write a sentence and add a reference.

Respond 11: Added as required. Line 122 and 129

Author Response File: Author Response.docx

Reviewer 2 Report

Rhizomes of Ginger are commonly used as a spice and for home remedies in either fresh  or dry form. This study aimed at assessing the effect of sun drying on the volatile constituents, total phenolic and flavonoid content, demonstrating how drying affected the antiviral activity of  ginger against low-pathogenic human Coronavirus, together with prediction of the antiviral effect of the major volatile compounds using molecular docking. 

The article has some interesting results related to the antiviral activity of ginger rhizomes bioactive compounds as affected by sun drying, but also related to the low-pathogenic human Coronavirus, being of high interest.

However, the article could be improved, so I suggested it acceptance with major revision.

My observations:

Abstract

The abstract includes more than 200 words. Please re-phrase it.

The abstract should be a single paragraph and should follow the style of structured abstracts, but without headings: 1) Background: Place the question addressed in a broad context and highlight the purpose of the study; 2) Methods: Describe briefly the main methods or treatments applied. Include any relevant preregistration numbers, and species and strains of any animals used. 3) Results: Summarize the article's main findings; and 4) Conclusion: Indicate the main conclusions or interpretations. The abstract should be an objective representation of the article: it must not contain results which are not presented and substantiated in the main text and should not exaggerate the main conclusions.

Phrase in lines 17-20 is too long. Please split it for a better understanding of the purpose of the work.

The affirmation ,,In addition, total phenolic and flavonoid content of both fresh and dried ginger de- 24 creased considerably,,  Did not decreased only or dried samples ?

Suggestion: This study aimed at assessing the effect of sun drying on the volatile constituents, total phenolic and flavonoid content and  the antiviral activity of ginger against low-pathogenic human Coronavirus.  The antiviral effect of the major volatile compounds was predicted through molecular docking.

In Lines 24-25  it is not clear why total phenolic and flavonoid content of both fresh and dried ginger de-24 creased considerably.

 

Introduction:

Is poorly written.

-I recommend starting with information from lines 44- 48, followed by information in lines 34-43.

-In lines 58 motivate the choice of sun drying among the all methos.

-In lines 60 move the information from lines 67-72, then continue with the information regarding the Coronaviruses.

-Lines 74 include ,,sun drying,,

 

 

Results and discussion

In line 82 Please add units before 1.51 ± 0.244 a

Lines 87, table S presents the classification in major groups. This could have been easily included in the main table. In table 1, the column showing the identification is redundant.

In my opinion it is enough to present the results in the main text and table 2 could be eliminated. Table 3 could be supplementary material instead. More discussion should be carried on related to TFC and antiviral activity based on literature data also, such as was performed in the case of TPC.

 

Information in line 153-154 is methodology.

 

Starting from line 197 a new section of results could be presented.

Figure S3 could be presented as main results.

 

Information in line 221 -239 should be moved to the introduction.

 

Maybe the loading plot (b) should be with dark font, because the blue color is creating informally a correlation only with the dried sample.

Was the PCA conducted on all volatile compounds or only on those which are common in both types of samples?

Table S2 should be presented as results in the main text. You can add the values in the brackets in lines 257-259.

 

 

4. Materials and Methods

In line 279 is not clear if sun dried samples were peeled or not prior to oil extraction.

In line 287 Determination of total phenolic content, is not clear if samples were peeled.

Methods 4.4 and 4.5 could be presented more specifically.

Author Response

The authors would like to thank you for your interesting and valuable comments which have been covered as follows:

Point 1:The abstract includes more than 200 words. Please re-phrase it.

Respond 1: The abstract now contains 198 words only as required.

Point 2: The abstract should be a single paragraph and should follow the style of structured abstracts, but without headings: 1) Background: Place the question addressed in a broad context and highlight the purpose of the study; 2) Methods: Describe briefly the main methods or treatments applied. Include any relevant preregistration numbers, and species and strains of any animals used. 3) Results: Summarize the article's main findings; and 4) Conclusion: Indicate the main conclusions or interpretations. The abstract should be an objective representation of the article: it must not contain results which are not presented and substantiated in the main text and should not exaggerate the main conclusions.

Respond 2: The abstract has been modified as directed.

Point 3: Phrase in lines 17-20 is too long. Please split it for a better understanding of the purpose of the work.

Respond 3: Corrected as required.

Point 4: The affirmation ,,In addition, total phenolic and flavonoid content of both fresh and dried ginger de- 24 creased considerably,,  Did not decreased only or dried samples ?

Respond 4: Corrected in the manuscript to dried ginger decreased considerably

Point 5: Suggestion: This study aimed at assessing the effect of sun drying on the volatile constituents, total phenolic and flavonoid content and  the antiviral activity of ginger against low-pathogenic human Coronavirus.  The antiviral effect of the major volatile compounds was predicted through molecular docking.

Respond 5: Thanks for your help. Taken into consideration and corrected in the manuscript. Line 17

Point 6: In Lines 24-25  it is not clear why total phenolic and flavonoid content of both fresh and dried ginger de-24 creased considerably.

Respond 6: These results have been discussed in the discussion section. Lines 223 to 233

Point 7: I recommend starting with information from lines 44- 48, followed by information in lines 34-43.

Respond 7: corrected as required.

Point 8: In lines 58 motivate the choice of sun drying among the all methods.

Respond 8: corrected line 56

Point 9: In lines 60 move the information from lines 67-72, then continue with the information regarding the Coronaviruses.

Respond 9: shifted as required

Point 10:Lines 74 include ,,sun drying,,

Respond 10: added as required

Point 11: In line 82 Please add units before 1.51 ± 0.244 a

Respond 11: Unit has been added as required.

Point 12: Lines 87, table S presents the classification in major groups. This could have been easily included in the main table. In table 1, the column showing the identification is redundant.

Respond 12: table S1 has been included in table 1 as required.

Point 13: In my opinion it is enough to present the results in the main text and table 2 could be eliminated. Table 3 could be supplementary material instead. More discussion should be carried on related to TFC and antiviral activity based on literature data also, such as was performed in the case of TPC.

 Respond 13:  Table 2 has been eliminated, table 3 has been moved to supplementary material and more discussion has been added as required.

Point 14: Information in line 153-154 is methodology.

Respond 14: This part has been moved to methodology section as required. Line 152

Point 15: Starting from line 197 a new section of results could be presented.

Respond 15: A new section has been added as directed. Line 304

Point 16: Figure S3 could be presented as main results.

 Respond 16: Added to the main results in manuscript

Point 17: Information in line 221 -239 should be moved to the introduction.

 Respond 17: Moved as required.

Point 18: Maybe the loading plot (b) should be with dark font, because the blue color is creating informally a correlation only with the dried sample.

Respond 18: The blue color of loading plot is a default in the Unscrambler software, so the score plot was modified to be in red color for the fresh ginger and purple color for the dry one

Point 19: Was the PCA conducted on all volatile compounds or only on those which are common in both types of samples?

Respond 19: PCA was conducted on all volatile compounds (all the metabolic profile in table 1 as mentioned in line 244, 245)

Point 20: Table S2 should be presented as results in the main text. You can add the values in the brackets in lines 257-259.

 Respond 20: added as required

Point 21:In line 279 is not clear if sun dried samples were peeled or not prior to oil extraction.

Respond 21: after peeling, added in the manuscript. Line 103

Point 22: In line 287 Determination of total phenolic content, is not clear if samples were peeled.

Respond 22: after peeling, added in the manuscript.

Point 23: Methods 4.4 and 4.5 could be presented more specifically.

Respond 23: presented as required.

Author Response File: Author Response.docx

Reviewer 3 Report

Dear authors,

Congratulation for your work and interesting results. I have some observation:

1. Why you put chapter Materials an methods as chapter 4? Usually this chapter are 2. Please change.

2. No chapter 3 in your paper? After 2 you pass directly to 4.

3. Please describe more GC-MS analysis, Determination of total phenolic content and Determination of total flavonoid. Also for the last two methods present in results the equation of the etalon curve.

 

Author Response

The authors would like to thank you for your interesting and valuable comments which have been covered as follows:

1. Why you put chapter Materials an methods as chapter 4? Usually this chapter are 2. Please change.

Respond 1: Changed as required

2. No chapter 3 in your paper? After 2 you pass directly to 4.

Respond 2: Results and discussion were incorporated together in one section.

3- Please describe more GC-MS analysis, Determination of total phenolic content and Determination of total flavonoid. Also for the last two methods present in results the equation of the etalon curve.

Respond 3: GC-MS analysis, Determination of total phenolic content and Determination of total flavonoid described as required. Calibration curves have been added in supplementary material as required.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

Thank you for the modifications.
The only part that could be now improved

is the conclusion section, since it presents

only general conclusions.

However, I recommended the publication of 

the article in the present form.