Antibacterial Effect of Combinations of Salvia officinalis and Glycyrrhiza glabra Hydroalcoholic Extracts against Enterococcus spp.
, Maria Cristina Marcucci 2, Amjad Abu Hasna 1,*, Marcia Carneiro Valera 1, Luciane Dias de Oliveira 2 and Cláudio Antonio Talge Carvalho 1Round 1
Reviewer 1 Report
No comments. All is well written.
Author Response
Dear reviewer
On behalf of my colleagues, I would like to thank you for the invaluable comments made to our paper, entitled “Antibacterial effect of combinations of Salvia officinalis and Glycyrrhiza glabra hydroalcoholic extracts against Enterococcus spp” We are hereby submitting the revised version, hoping that it is now deemed worthy of publication in the Coatings.
Reply to reviewer
- Concern of the reviewer: No comments. All is well written.
Our response: Dear reviewer, thank you for your comment.
Looking forward to hearing from you.
Yours sincerely.
Reviewer 2 Report
This work investigated antimicrobial efficacy of hydroalcholic extracts from Salvia officinalis and Glycyrrhiza glabra. The chemical composition of the extracts was analyzed HPLC and the antibiofilm activity was evaluated in E. faecalis and E. faecium medium. This combinations demonstrated high antimicrobial efficacy, making it as a promising alternatives in anti-bacterial applications. This work should be of significant impact and interest to the broad readership of Coatings, including those in the clinical research, antibacterial material and biomedical communities.
However, some changes still needs to be made before publication:
1. Chromatogram results in Figure 1 and Figure 2. were stretched and the title of X-axis and Y-axis was not clear. The major peaks of chromatograph were recommended to be marked using different colors (the current version just using cross lines).
2. In Results part (line 179, Figure 2 and Figure 4), the author gives the chemical structures of identified compounds isolated from the Salvia officinalis and Glycyrrhiza glabra. This part is not quite convincing, as HPLC-DAD works well in material isolation and purification but not in detecting the exact structure. The author should give some proof (i.e., NMR or UV spectra, or Mass spectra of the isolated material) to convince the readers about the chemical composition. If not, listing them as “identified compound” was not convincing.
3. “Inoculum Preparation” (line 96) points out the use of three clinical strains of E. faecalis and two clinical strains of E. faecium. However in Table 1, it is the only place the author use the term “E. faecalis clinical strain 2, strain 3”. It would be nice to elucidate the differences between the clinical strains and explain why the extracts showed synergistic effects against clinical strain 1 and ATCC, but not effective in the other strains. (Line 212).
4. Line 233, “strains 2 and 3” should be “strain 2 and strain 3”.
5. The conclusion part are recommended to be furhter polished. It seems too simple and hard to conclude the whole idea of this paper.
Author Response
Dear reviewer
On behalf of my colleagues, I would like to thank you for the invaluable comments made to our paper, entitled “Antibacterial effect of combinations of Salvia officinalis and Glycyrrhiza glabra hydroalcoholic extracts against Enterococcus spp” We are hereby submitting the revised version, hoping that it is now deemed worthy of publication in the Coatings.
Reply to reviewer
- Concern of the reviewer: Chromatogram results in Figure 1 and Figure 2. were stretched and the title of X-axis and Y-axis was not clear. The major peaks of chromatograph were recommended to be marked using different colors (the current version just using cross lines).
Our response: Dear reviewer, thank you for your comment. I am afraid that we will not be able to alter the figure as it is automatically generated by the chromatography equipment.
- Concern of the reviewer: In Results part (line 179, Figure 2 and Figure 4), the author gives the chemical structures of identified compounds isolated from the Salvia officinalis and Glycyrrhiza glabra. This part is not quite convincing, as HPLC-DAD works well in material isolation and purification but not in detecting the exact structure. The author should give some proof (i.e., NMR or UV spectra, or Mass spectra of the isolated material) to convince the readers about the chemical composition. If not, listing them as “identified compound” was not convincing.
Our response: I appreciate the detailed observation. Indeed, HPLC-DAD allows us to isolate certain compounds. For instance, in the extract of S. officinalis, derivatives of chlorogenic acid and some flavonoids resembling apigenin have been identified. In the extract of G. glabra, some derivatives of liquiritigenin and isoliquiritigenin have been described. However, the description and interpretation of the chromatograms do not provide conclusive information about the exact structure of these compounds. Although we included images of chemical structures for illustration purposes, they do not accurately represent the identifications. Therefore, to avoid misleading interpretations by readers, we have chosen to remove these images.
- Concern of the reviewer: “Inoculum Preparation” (line 96) points out the use of three clinical strains of E. faecalis and two clinical strains of E. faecium. However in Table 1, it is the only place the author use the term “E. faecalis clinical strain 2, strain 3”. It would be nice to elucidate the differences between the clinical strains and explain why the extracts showed synergistic effects against clinical strain 1 and ATCC, but not effective in the other strains. (Line 212).
Our response: We appreciate the suggestion to clarify the details. We have added the following table describing the resistance profile of clinical strains of E. faecalis and E. faecium that were isolated and collected from teeth with endodontic infections. The collection and identification of these strains were conducted at our institution for the study by Santos in 2014. The bibliographic reference has also been appended at the end of the manuscript.
Santos, Ana Carolina Chipoletti dos PREVALÊNCIA, VIRULÊNCIA E SENSIBILIDADE ÀS TERAPIAS ANTIMICROBIANAS DAS CEPAS DE Enterococcus faecalis E Enterococcus faecium ISOLADAS DE INFECÇÕES ENDODÔNTICAS / Ana Carolina Chipoletti dos Santos. - São José dos Campos : [s.n.], 2014. 92 f.
- Concern of the reviewer: Line 233, “strains 2 and 3” should be “strain 2 and strain 3”.
Our response: thank you, this was corrected.
- Concern of the reviewer: The conclusion part are recommended to be furhter polished. It seems too simple and hard to conclude the whole idea of this paper.
Our response: the conclusion was reformulated. Many thanks.
Looking forward to hearing from you.
Yours sincerely.
Reviewer 3 Report
Dear Authors,
Your article entitled” Antibacterial effect of combinations of Salvia officinalis and Glycyrrhiza glabra hydroalcoholic extracts against Enterococcus spp” brings useful information on the topic and it is also well organized.
I hope that my recommendations will help you to improve the quality of your work.
In the Materials and Methods section:
2.2. High-Performance Liquid Chromatography (HPLC) analyses of plant extracts
- Lines 85-94 Please correct the duplication of information.
In the Results section:
3.1.1. Salvia officinalis extract
- In my opinion, the paragraph between lines 182-184 and figures should be as follows:
” By chromatographic analysis, it was observed that some chlorogenic acid derivatives (Figure 1a) at 11.36 min, rutin (Figure 1b) was found at 27.09 min and some flavonoids (Figure 1c) which could be apigenin at 30.69 min (Figure 2).
Figure 1. Structures of identified compounds isolated from the Salvia officinalis extract: chlorogenic acid, flavonoids (apigenin) and rutin- Please add the numbers (a-c) and order the structures to match the sequence in the text: chlorogenic acid, rutin, and flavonoids (apigenin).
Figure 2. Chromatogram of Salvia officinalis extract. Chromatogram wavelength at 280 nm. - Please note that this figure requires a higher resolution for better clarity.
3.1.2 Glycyrrhiza glabra extract
- In my opinion, the paragraph between lines 192-193 and figures should be as follows:
” By chromatographic analysis, it was observed some liquiritigenin (Figure 3a) and isoliquiritigenin (Figure 3b) derivatives at the retention time (Rt) of 17.78 min and 20.81 min (Figure 4).
Figure 3. Structures of identified compounds isolated from the Glycyrrhiza glabra extract: liquiritigenin and isoliquiritigenin. - Please add the numbers (a, b).
Figure 4. Chromatogram of Glycyrrhiza glabra extract. Chromatogram wavelength at 280 nm. -Please note that this figure requires a higher resolution for better clarity.
In the Discussion section:
- Please endeavor to minimize the repetition of information between the results section and the discussion section of the article (lines 248-249; lines 252-253).
- Please include a paragraph discussing the limitations of the study.
Author Response
Dear reviewer
On behalf of my colleagues, I would like to thank you for the invaluable comments made to our paper, entitled “Antibacterial effect of combinations of Salvia officinalis and Glycyrrhiza glabra hydroalcoholic extracts against Enterococcus spp” We are hereby submitting the revised version, hoping that it is now deemed worthy of publication in the Coatings.
Reply to reviewer
- Concern of the reviewer: In the Materials and Methodssection:
2.2. High-Performance Liquid Chromatography (HPLC) analyses of plant extracts
- Lines 85-94 Please correct the duplication of information.
Our response: Dear reviewer, thank you for your comment.
- Concern of the reviewer: In the Resultssection:
3.1.1. Salvia officinalis extract
- In my opinion, the pa…
Our response: All your suggestions were followed and are highly appreciated.
- Concern of the reviewer: In the Discussionsection:
- Please endeavor to minimize the repetition of information between the results section and the discussion section of the article (lines 248-249; lines 252-253).
- Please include a paragraph discussing the limitations of the study.
Our response: All your suggestions were followed and are highly appreciated.
Looking forward to hearing from you.
Yours sincerely.
