In Vitro Anti-Wrinkle and Skin-Moisturizing Effects of Evening Primrose (Oenothera biennis) Sprout and Identification of Its Active Components
Round 1
Reviewer 1 Report
The present study aimed to investigate the effect of Oenothera biennis sprout extract 19 (OBS-E) on skin-function improvement and to identify its pharmaceutically active components but Skin-function improvement, anti-wrinkle and skin-moisturizing effects were not tested on human skin.
Please change the title as a work of evidence on the skin is expected directly.
The work is well structured and easy to read but it lacks real novelty despite the use of sprouts instead of roots or seeds.
Major points:
Indicate in the title, in the abstract and in the text that the work is not carried out directly on humans but is an in vitro study, as it can lead to confusion in the reader.
Why the Antioxidant and Elastase Inhibition Activities were not tested on fibroblasts and keratinocytes directly? ascorbic acid is a secondary antioxidant. It will be better to measure H2O2 production or catalase and SOD activities or other ROS assay.
line 60: i think there is an error in the author: "Furthermore, Kwak, Kim, Kim, Park, Kim and Kang [8]...
Author Response
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Reviewer 2 Report
First of all the article is clear, well written and easy to understand.
The problem is that the demonstration in connection with the title is quite light. Indeed it is not possible to write that an extract is antiwrinkle or skin-moisturizer only based on vitro tests or link with expression of genes. These remarks does not affect the quality of the article but the title must be changed. for example for something like :
Potential of ...
In my opinion the article would be more suitable in Cosmetics journal rather than in Processes journal.
The bibliographic part is well documented.
Just a little mistake page 2 line 51 it is : "nutraceuticals"
Author Response
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Reviewer 3 Report
The manuscript "Evaluation of anti-wrinkle and skin-moisturizing effects of evening primrose (Oenothera biennis) sprout and identification of its active components" submitted to Processes for publication as original research article seems to be very interesting and appropriate for the journal.
The manuscript is well written, experiments well described and results clearly presented.
I have only a question and a request:
Question: Why MMP9 was not evaluated. it is one of the most involved MMP in skin moisturizing and regenerative effect.
Request: Please insert a figure with the structures of the chemical constituents.
Author Response
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Reviewer 4 Report
Dear authors
The manuscript processes-1040102, by Kim et al., describes the identification and quantification of Oenothera biennis L. ethanolic extracts constituents (4 compounds) and the biological activities related with anti-aging effects such as antioxidant activity, inhibition of elastase, MMP-1 and MMP-2 enzymes, production of hyaluronic acid and the expression of moisturizing genes.
Oenothera biennis L. is a species that arouses a lot of commercial and scientific interest. Many works on biological activities of this species and its constituents have been published, including several review articles that the authors should have cited in their introduction (for example Asian Pac J Trop Biomed 2017; 7 (11): 1046–1054 and Antioxidants 2018, 7, 108; doi: 10.3390 / antiox7080108).
As the authors refer, the sprout are not much studied and, in this respect, the article exhibits some novelty.
However, the manuscript exhibits several weaknesses described below:
As referred above, the introduction doesn't include all relevant references. Several relevant reviews are not cited.
The description of the methods has many flaws, contradictory and/or missing information. For example, right on line 73, the first sentence of point 2.1, the authors refer that in this study they use fresh plant (the place of harvest, relevant data in research on natural products, is very broadly indicated) while on line 76 they mention that "... dried OBS obtained from Dain Natural Co, Ltd. was ground ... and extracted ...). After all, the reader does not understand what plant material was studied. If it was the purchased dry material, what is the purpose of genetic identification? of fresh vegetable, if it was not the extract of the latter that was the object of chemical analysis and biological activities !!
The information contained in the following sentence "... and then extracted by refluxing with seven volume of 50% (v / v) ethanol for 24h at room temperature (RT)" does not allow to reproduce the extraction. Is the extraction by reflux or at room temperature? It can't be both! The solvent is 50% ethanol. What is the composition of the remaining 50%? The authors used seven volumes of what?
The authors do not present the mass of plant material used to obtain the extract. This data is useful.
Some of the experimental conditions used promote the degradation of the constituents. Drying the extract at 70º is one of those conditions. When investigating natural products, authors should use temperatures below 45ºC.
In assessing biological activities, the authors never indicate the concentration of the extract stock solution, indicating only the microliters of stock solution used. Thus, no investigator will be able to reproduce the method.
The authors do not present information on how they quantify the 4 compounds identified: did they use the straight-line method? For what range of concentrations? Did you use the response factor method?
Regarding the results presented in table 1 (this table should appear close to the place where it is quoted for the first time and not at the end of the "results" section) these are irrelevant for the following reasons:
1) no statistical parameters, such as standard deviation or standard error, are presented associated with the values ​​presented, which means that they lose impact.
2) using adequate positive control is good practice in assessing biological activities. However, not choosing any substance for that function or using the same control for activities in which the target is completely different is inappropriate. Ascorbic acid is a good antioxidant and is, therefore, good control for anti-radical activities. It is not a good elastase inhibitor and therefore it is not a good positive control for this activity. Of course, using inappropriate controls makes the activity of the samples seem much more significant than they are.
3) More than one data lead to the conclusion that the ascorbic acid used in this analysis is already degraded. This compound is known to be a strong antioxidant. However, the results presented show that ascorbic acid exhibits greater anti-elastase activity than antioxidant activity, which goes against everything published. Besides, from experience and results published by other authors, the IC50 of ascorbic acid is in the order of 2-10 microg / mL (see for example Phytother. Res. 25: 1451–1456 (2011)) while the authors present values 10 to 20 times higher than indicated in the literature.
The authors exaggerate the terms potent and outstanding (abstract, discussion, conclusions) to describe the antioxidant effect of the extract, which in no way corresponds to reality.
Regarding the discussion, the authors should be more objective and present not only the observed effect but also the concentration for which the observed effect is statistically relevant. It is surprising that the authors present this type of discussion for data in the literature (see for example lines 297-299) but do not do so for the data themselves (compare with lines 295-297).
Attention to some formalisms:
1) The Latin botanical name must always be written in italics and at least in the abstract in the introduction and in the experimental part the full name, including the authority name, must be presented.
2) in chemical formulas, stoichiometric coefficients must appear in subscript as well as in "IC50".
3) Pay attention to how they express some units (e.g. molar absorptivity 0.7 cm-1M-1).
4) the authors use many abbreviations created by themselves, among others, throughout the text, but do not present any list of abbreviations, which forces the reader to walk around the text looking for the meaning of a given abbreviation.
Conclusions: The authors did not evaluate the biological activity of the compounds identified in the extract, therefore, the data presented do not allow to go as far as the authors believe in the conclusions.
Author Response
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Round 2
Reviewer 1 Report
the authors provide all the changes required to the manuscript which is now suitable for pubblication.
Author Response
Point 1: The authors provide all the changes required to the manuscript which is now suitable for publication.
Response 1: We are greatly appreciate your review opinion which have been very helpful for improving the quality of our manuscript.
Reviewer 4 Report
Dear authors
The manuscript processes-1040102, by Kim et al., was significantly improved and justified some unmodified points in an acceptable way.
However, some minor points must be corrected
- Authors must be consistent throughout the text. Line 324, should be antioxidative instead anti-oxidative. Could be aging or ageing depending on whether it is British or American English. However, authors must be consistent and use only one of the forms and not both throughout the text.
- Should be antipsoriasis instead anti-psoriasis.
- The final list of references should be carefully reviewed. Please see the instructions for authors. For example, ref. 19, 27, 38 … missing the indication of some authors; The abbreviated journal name should use points (for example “Asian Pac. J. Trop. Biomed.” instead “Asian Pac J Trop Biomed”.
Author Response
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