Scrophularia buergeriana Extract Improves Memory Impairment via Inhibition of the Apoptosis Pathway in the Mouse Hippocampus

Round 1

Reviewer 1 Report

I have one important remark concerning Manuscript. Desecription and discussion of results is focused on differences between mices trated with Ab and Ab-SBE treated mices. FFigures suggest that there is well visible difference between control and SBE-treated mices. Is this difference statistically significant? if not it should be clearly stated. If yes this result should be discussed to avoid overoptomism in interperation of results.

Figures 3, 5, 6 and 7 should be enlarged. Figures may be arranged vertically.

Minor remark. In introduction Authors write about bioactive components of Scrophularia buergeriana. Please add CAS regisry nymbers or PubChem CIDs ot these compounds. If Authors decide to use PubChem, please cite website and the most recent article describing the database.

Author Response

Dear reviewer,

Thank you for your review suggestion of this manuscript.

I corrected and added the manuscript by reviewer's suggestion.

Please confirm respond and the revised manuscript.

Sincerely,

Seung Hwan Yang.

Author Response File: Author Response.docx

Reviewer 2 Report

This is an interesting study to reveal the potential neuroprotective effect of SBE in beta-Amyloid (Ab)-induced amnesia. It was exciting to see SBE delaying Ab-induced loss of cognition.  The study will be improved further if the study was carried with older animals as Alzheimer’s disease happens mainly in older generation. Brain in young animal has better plasticity than the old animal for recovery.

1. Consistent the abbreviations used, glutathione peroxidases (GPx) in line 41, but it was GP in line 50.
2. “b” was missing in many “Ab” treated group in line 190, 213, 213, 241, 305, 315 & 318.
3. In the passive avoidance test, could author state how many animals were excluded from the experiments in each group due to their training failure.
4. Authors need to include SBE-treated group to show whether SBE alone has an effect.
5. In Figure 5, the results will be more convincing to directly measure the activity of SOD1, SOD2 and GPx rather than simply their protein levels. There are assay kit commercially available for those enzymes. Enzyme’s protein level does not always reflect its activity.
6. Immunohistochemical images of brain sections are required to show accumulation of Ab in neural or neuronal cells of the hippocampus and whether SBE administration reduced apoptosis in particular cell types or in general.
7. In line 245 “Mitochondrial permeability was increased due to the suppressed Bcl-2/Bax expression, subsequently leading the cleavage and downstream activation of multiple caspase cascades.”. Could authors rephase this sentence as there was no result provided for mitochondrial permeability. Therefore it is inappropriate to say reduced Bcl2/Bax leading to increase mitochondrial permeability.
8. Authors will require to present reduced apoptotic neural cells in brain section using immunohistochemistry for apoptotic markers such as TUNEL staining in order to claim SBE showed neuroprotective effect.
9. “The present study is the first report to identify the neuro-protective activities, including amyloid-beta clearance effects”. Stated of “amyloid-beta clearance effect” is a complete misleading as the results did not show SBE clearing Ab because of current experimental design. SBE was administrated after 1 day of Ab Therefore, SBE likely prevents accumulation of Ab. If authors would like to claim “clearance effect”. After injection of Ab, the animals should leave for 2 to 3 week to accumulate Ab in the brain before administration of SBE and investigate whether there is still neuroprotective effect.
10. In Figure 8, there should be bi-directional arrows between dysfunctional mitochondria and increased ROS as well as reduced anti-oxidant enzymes and increased ROS.

Author Response

Dear reviewer,

Thank you for your review suggestion of this manuscript.

I corrected and added the manuscript by reviewer's suggestion.

Please confirm respond and the revised manuscript.

Sincerely,

Seung Hwan Yang.

Author Response File: Author Response.docx

Reviewer 3 Report

Review Report

 The manuscript entitled- “Scrophularia buergeriana extract improves memory impairment via inhibition of the apoptosis pathway in the mouse hippocampus” is interesting and provides the basis for publication. In this study the authors reported that SBE treatment improves learning and memory function in a beta-amyloid induced memory loss mice model and has potential to be used as a health functional food. Further, they also showed that SBE exhibited antioxidant and neuro-protective effects through inhibiting apoptosis. I would recommend this work for publication with some corrections.

Comments-

1. The western blot bands are very faint and blurred for glutathione peroxidase-1 (GPx-1) in Fig.5
2. Beta-amyloid deposition is associated with induction of neuroinflammation and memory loss. It would be worth exploring if SBE attenuates inflammatory mediators in beta-amyloid induced memory loss mice model in this or near future studies.

Author Response

Dear reviewer,

Thank you for your review suggestion of this manuscript.

I corrected and added the manuscript by reviewer's suggestion.

Please confirm respond and the revised manuscript.

Sincerely,

Seung Hwan Yang.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Authors have added few sentences about differences between Control and SBD group. I would like to ask Authors to indicate in Figures all statistically significant differences. It will support discussion. I would like to apologize if my previous remark was unclear.

Author Response

Dear reviewer.

 

Thank you for your review in this manuscript.

I attached the response to your suggestion.

Best regards,

Author Response File: Author Response.docx

Reviewer 2 Report

No more comments

Author Response

 

Dear reviewer.

 

Thank you for your review in this manuscript.

Author Response File: Author Response.docx