Grape Seed Proanthocyanidins Inhibit Replication of the Dengue Virus by Targeting NF-kB and MAPK-Mediated Cyclooxygenase-2 Expression
, Chung-Hao Huang 5,6,7, Yao-Chin Hsu 8,* and Jin-Ching Lee 1,2,4,*Round 1
Reviewer 1 Report
The manuscript reported by We-Chun Cen et al evaluates the efficacy of grape seed proanthocyanidins extract (GSPE) on anti-dengue virus infection. They found that GSPE treatment reduces COX-2 expression by inhibiting virus-induced NF-kB and MAPK activation, thus suppresses DENV replication. The authors further showed that administration of GSPE reduces the production of inflammatory cytokines with associated with the development of severe dengue disease. The experiments are well-designed to address the scientific questions the authors raised. The findings are interesting and convincing. The concerns raised by reviewers are listed below.
1. The authors described “~GSPE significantly decreased monocyte infiltration in the untreated control group (Figure. 5d). (Page 9, line 325)”. It should be GSEP treated group had a significantly decreasing in monocyte infiltration.
2. In figure 5D, the error bar should be added to the graph.
3. The sentence “Further investigation to evaluate the anti-hemorrhagic effect in vivo using the DENV-infected AG129 mouse model [47]. (Page 11, line 389-390)” is incomplete and should be modified.
4. The authors claim that GSPE would be a potential dietary supplement to attenuate DENV infection and severe dengue. However, the compounds in GSPE, such as resveratrol, quercetin, catechin, epicatechin, and procyanidins etc. might be modified by digestive enzymes. I assume that administration route of GSPE in the submitted manuscript is intravenous injection. Thus, the efficacy of GSPE on anti-DENV might be altered due to the difference of routes of administration. This issue should be discussed in the “Discussion” section. In addition, the administration route of GSPE should be clearly provided in the manuscript.
5. The citation of Reference should be rearranged by reference management tools, e.g. Endnote. There are errors in the numbering of reference citations in the manuscript.
Author Response
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Reviewer 2 Report
This interesting study investigated the anti dengue activity of grape seed proanthocyanidins extract in Huh-7 cells and ICR mice.
The methodology is given fully for many aspects and needs to be provided.
The methodology for antiviral assay in Huh-7 cells is not provided. At what time point after infection, the drug is provided.
How the DENV RNA is quantified. Using in-vitro RNA standards?
How plaque assay was performed
What is the route of infection for suckling mice
What is the route of drug administration and time of administration of drug in mice
Figure 5a. The survival rate in mice treated with drug is not plotted in the graph
It has been mentioned that drug was administered 1, 3 and 5dpi. It is not clear that results were presented for which days in case of survival rate, body weight, virus titre and monocyte infiltration.
Author Response
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Reviewer 3 Report
Comments:
The design of this paper is relatively reasonable and reliable. In this study, anti-dengue virus avtivity of edible grape seed proanthocyanidins was discussed. This research has certain theoretical significance and practical value. However, this thesis still has some problems.
1. In Figure1(a), 2(c), I don’t think the images of GAPDH played their role. The bands were unevenness. Please give an explanation.
2.Every figure of western blotting was not evaluated by Gray value analysis. Please add it.
3.I don’t think the images(Figure5d) of immunohistochemical (IHC) assay were convinced. Fields of view weren’t focus on the same place. Images weren’t enough clear. Please state it clearly.
4.Pay attention to format. The label under figure used lowercase like (a), but in explanation about figure used (A). Please correct it.
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Round 2
Reviewer 2 Report
Though the authors have done revisions, still the manuscript needs to be improved. The following are the comments
Line 110 which presented 1 following quantification of band intensity in X-film…………….. X fim or X-ray film? What is presented 1
Line 153 The mice were intracerebrally injected virus…………………………….injected with virus
Line 155-156 group 3 first received 1 × 105 PFU DENV, and received 20 mg/kg GSPE at 1, 3, and 5 days post-infection…………….. In response the authors have mentioned intracerebral route but not in methods
Line 167-168 Cells were fixed and stained with the plaque assay solution (1% crystal violet, 0.64% NaCl, and 2% formalin) at 25 °C for 2 h………………………..This step is done after five days of incubation. If you fix cells with formalin, cells will die. The protocol needs revision?
Line 189-190 No significant cytotoxicity was detected in the GSPE-treated cells compared to the untreated cells ac-190 cording to the MTS assay (Figure. 1c)………………………………..Suddenly MTS is coming . What is MTS. It is not mentioned earlier
Line 250 -251 Similarly, the DENV RNA levels were also restored in proportion to exogenous COX-2 expression under the GST treatment………………………GST treatment or GSPE
Figure 4b What is NE. How it is prepared? Mention in methodology
Line 332 five ransom images………………………ransom or random
Figure 5. The results were collected. But which day results were plotted?
The manuscript needs to be thoroughly checked for typos.
Author Response
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