Reduction of the Plasma Uric Acid Level in Potassium Oxoate-Induced Hyperuricemic Rats by Heat-Concentrated Prunus mume Fruit Extract Containing Three Chlorogenic Acid Isomers

Round 1

Reviewer 1 Report

In the current works, Yi-Ching Wu and Ping-Chung Kuo provide an empirical association between mei extract and reduce the risk of gout. Interestingly, oral administration of the mei extract reduced the plasma uric acid level in hyperuricemic rats without elevating urinary uric acid levels. Moreover, the authors find that chlorogenic acid isomers as the active ingredients in mei extracts. The manuscript is well-written and easy to read, and the method section contains all the valuable information to reproduce the experiments. However, some minor modifications could improve the quality of the manuscript.

a) since the PO's 8-hour urine uric acid excretion level was not significant, did the author analyse the samples at a different time point? If so, please comment.

b) Be consistent in the figure legends. Annotate the values of significance with either * or #.

c) which statistical test was used to calculate significance?

d) the authors could expand the conclusion section without overinterpreting the data by giving a more detailed explanation of the obtained results.

e) in the Discussion, it would be interesting to speculate on how mei extract lowers hyperuricemia. Do the authors think mei extracts could also impact inflammatory cells that could benefit gout patients during the flare stage?

Author Response

please see the attached file.

Author Response File: Author Response.pdf

Reviewer 2 Report

The authors demonstrated that Prunus mume, an extract of the plum tree, has a uric acid-lowering effect. This manuscript is very interesting. However, this study needs some refinements.

Major comments:

1. The authors should state why there is no difference in serum uric acid levels between low and high dosage of mei extract in Figure 4.

2. When considering urinary uric acid excretion, the urinary uric acid / creatinine ratio (UUA / UCr) and fractional excretion of uric acid (FEUA) should be used in Figure 5.

Minor comments:

1. The abbreviation “AP” in Figures 4 and 5 should be written “allopurinol (AP)” in figure legends.

Author Response

Please see the attached file.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The authors revised the manuscript in accordance with the reviewers' comments. The issues have been resolved and the manuscript is considered suitable for publication.