Screening of Antibacterial Activity, Antioxidant Activity, and Anticancer Activity of Euphorbia hirta Linn. Extracts

Round 1

Reviewer 1 Report

The manuscript entitled “Screening of antibacterial activity, antioxidant activity, and anticancer activity of Euphorbia hirta Linn. Extracts.” have described the biological activities of E. hirta extracts  using antimicrobial, cytotoxicity, phytochemical analysis and antioxidant assay.

Authors should correct manuscript according to the suggestion and completed some information.

Minor issues

Abstract

In my opinion abstract should be corrected. Abstract should be re-edited. At the beginning, give the purpose of the work, then briefly characterize the methods used, give the results of the research and the most important observations. Abbreviations in abstract should be defined.

Line 9: this sentence is suited better for Introduction

Materials and Methods

Line 183: it should be “McFarland”

Line 188: “25.0 mL” is correct values? Please give correct values for testing samples

Line 233: “..providing 50% inhibition of …? In my opinion IC50 definition should be completed

Results

In all Tables and Figures authors should provide significant information

Discussion

Line 366: authors should explain influence of solvent for phenolic compounds extraction This information are in 389 – 393, discussions need to be reorganized

Line 374 – 380: the authors should explain the importance of these bacteria for health, the connection with the topic of the work should be shown

References

References no 14 and 54 should be corrected according to journal guide

Author Response

RESPONSE TO REVIEWER 1

On behalf of the authors, I would like to thank the reviewer for your comments which help us to significantly improve the manuscript.

Minor issues

Abstract

In my opinion abstract should be corrected. Abstract should be re-edited. At the beginning, give the purpose of the work, then briefly characterize the methods used, give the results of the research and the most important observations. Abbreviations in abstract should be defined. à We had revised the structure and content of this part. Please read the new abstract.

Line 9: this sentence is suited better for Introduction à The sentence had been revised.

Materials and Methods

Line 183: it should be “McFarland” à The mistake had been revised.

Line 188: “25.0 mL” is correct values? Please give correct values for testing samples à The mistake had been revised.

Line 233: “..providing 50% inhibition of …? In my opinion IC50 definition should be completed à The definition had been added.

Results

In all Tables and Figures authors should provide significant information à The mistake had been revised.

Discussion

Line 366: authors should explain influence of solvent for phenolic compounds extraction This information is in 389 – 393, discussions need to be reorganized à The mistake had been revised.

Line 374 – 380: the authors should explain the importance of these bacteria for health, the connection with the topic of the work should be shownà The information had been added.

References

References no 14 and 54 should be corrected according to journal guide à The references had been revised.

Reviewer 2 Report

The abstract is too long and hard to be understood. The authors must reorganize it, and better present the results.

Abbreviations must be defined at their first appearance in the text, even in the abstract.

In the introduction, more information should be provided abut the beneficial effects of Euphorbia hirta and the authors must better explain why they chose to evaluate the antibacterial, antioxidant, and anticancer effects of this plant.

Materials and Methods do not mention anything about Ethics Committee approval.
The authors must give more information about the study groups : how many rats were in one group, were they randomized?
2.4.1. Determination of total phenolic content (TPC) "The experimental results were expressed as mean ± Standard Error of Mean (SEM) of three replicates." It is also mentioned in 2.8. Statistical analysis section
"The percentage of growth inhibition (Inh %) " but in Figure 5 abbreviation used is "I%"

Results

There are plenty of values not followed by the unit of measurement
Abbreviations and study groups should be defined at the bottom of each table/figure
It is useless to repeat in the text values presented in the tables.
information about "The SRB assay (Sulforhodamine B)" should be given in the Materials and Methods section, not in the Results

Discussion

"EH-EA had the highest total phenol content (254.96 ± 10.05 mg GAE/g extract) and the highest total flavonoid contents (27.66 ± 0.73 mg quercetin/g extract"m instead of values the authors should refer to table/figures

Conclusions should be more specific for the results on E. hirta.
"Recent investigations have proved that secondary metabolites from natural resources containing bioactive components have a wide variety of biological properties." and "And it is necessary to elucidate the mechanisms of action of these extracts and bioactive compounds isolated from this plant at the cellular and molecular level to evaluate biological capacity of substances on specific properties." are too general.

In the whole manuscript, the expression "five extracts samples of E. hirta" is used too often

Author Response

RESPONSE TO REVIEWER 2

On behalf of the authors, I would like to thank the reviewer for your comments which help us to significantly improve the manuscript.

The abstract is too long and hard to be understood. The authors must reorganize it, and better present the results. à We agree with reviewer at this point. The abstract had been rewritten.

Abbreviations must be defined at their first appearance in the text, even in the abstract. à The mistake had been revised.

In the introduction, more information should be provided about the beneficial effects of Euphorbia hirta and the authors must better explain why they chose to evaluate the antibacterial, antioxidant, and anticancer effects of this plant. à The information had been added.

Materials and Methods do not mention anything about Ethics Committee approval.
The authors must give more information about the study groups: how many rats were in one group, were they randomized? à The information had been added.

2.4.1. Determination of total phenolic content (TPC) "The experimental results were expressed as mean ± Standard Error of Mean (SEM) of three replicates." It is also mentioned in 2.8. Statistical analysis section "The percentage of growth inhibition (Inh %) " but in Figure 5 abbreviation used is "I%" à The mistake had been revised.

Results

There are plenty of values not followed by the unit of measurement à The mistake had been revised.
Abbreviations and study groups should be defined at the bottom of each table/figure
It is useless to repeat in the text values presented in the tables. à The mistake had been revised.
information about "The SRB assay (Sulforhodamine B)" should be given in the Materials and Methods section, not in the Results à The mistake had been revised.

Discussion

"EH-EA had the highest total phenol content (254.96 ± 10.05 mg GAE/g extract) and the highest total flavonoid contents (27.66 ± 0.73 mg quercetin/g extract"m instead of values the authors should refer to table/figures à The mistake had been revised.

Conclusions should be more specific for the results on E. hirta. "Recent investigations have proved that secondary metabolites from natural resources containing bioactive components have a wide variety of biological properties." and "And it is necessary to elucidate the mechanisms of action of these extracts and bioactive compounds isolated from this plant at the cellular and molecular level to evaluate biological capacity of substances on specific properties." are too general.

We have revised this session. Please read the text in new manuscript.

In the whole manuscript, the expression "five extracts samples of E. hirta" is used too often à The mistake had been revised.

Reviewer 3 Report

The article is very badly written with too much of non-contextual background information. Requires a complete English language correction. Sentences are giving wrong meaning and there are lots of rooms for improvement in the manuscript. Some of the comments are given below-  

• There is no details on ethical committee approval for animal studies.
• In several places' authors have confused with the units of measurements (kg, mg and mcg). Some of the volumes which the authors described in the manuscript are unrealistic (for example, they used 8 kg of plant material for extraction, 25 ml solution/ extract on the wells for in vitro anti-microbial testing).
• No positive control is used in anti-microbial testing assay.
• Statistical validation is not indicated in the figures.
• In several places, the phrase 'diluted water' has been mentioned.

Overall, this manuscript requires a complete re-writing and cannot be accepted for publication in the present form. I strongly encourage the authors to improve the English of the whole manuscript by a native English speaker or through some editing service, improve the flow of reading and resubmit a REVISED manuscript.

Author Response

RESPONSE TO REVIEWER 3

On behalf of the authors, I would like to thank the reviewer for your comments which help us to significantly improve the manuscript.

• There is no details on ethical committee approval for animal studies.
  • We had included this information
• In several places' authors have confused with the units of measurements (kg, mg and mcg). Some of the volumes which the authors described in the manuscript are unrealistic, for example:

          They used 8 kg of plant material for extractionà We used a large amount of crude materials for further research, for example, evaluation of effect of E. hirta Linn. extracts on plasma glucose on normal mice, investigation of alpha-amylase and alpha-glucosidase inhibition in vitro testing, and isolation of bioactive compounds from extracts.

          25 ml solution/ extract on the wells for in vitro anti-microbial testing). à The mistake had been revised.

• No positive control is used in anti-microbial testing assay.

The strains used to test are reference strains, as a control for test.

Because these extracts are newly implemented and tested for antibacterial activity, there is not a single positive control for this type of extract. If an antibiotic plate is used as a positive control, it is not correct because the antibiotic plate only helps to determine how highly resistant the strain is compared to the extract.

The quality of standard strains of bacteria is always checked regularly by the laboratory before using it in resistance tests, because it is a neccesary requirement for ISO 15189: 2012 standardized laboratories - standard recognized of the laboratory of Ho Chi Minh City Pasteur Institute, Vietnam.

The strains selected for testing cause diarrhea, acute diarrhea and pneumonia, ect…are diseases with a high mortality rate.

• Statistical validation is not indicated in the figures à The mistake had been revised.
• In several places, the phrase 'diluted water' has been mentioned. à The mistake had been revised.
• Overall, this manuscript requires a complete re-writing and cannot be accepted for publication in the present form. I strongly encourage the authors to improve the English of the whole manuscript by a native English speaker or through some editing service, improve the flow of reading and resubmit a REVISED manuscript. à We had proofread the whole mauscript. We hope the new version is suitable for publication.

Round 2

Reviewer 2 Report

Even if the authors said that they did the revisions suggested, I did not actually see many of them made in the new form of the manuscript.