Effects of Purified Vitexin and Iso-Vitexin from Mung Bean Seed Coat on Antihyperglycemic Activity and Gut Microbiota in Overweight Individuals’ Modulation

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This article is significant because it explores the synergistic effects of vitexin and iso-vitexin, two bioactive compounds found in mung bean seed coat, on antihyperglycemic activity and gut microbiota regulation in overweight individuals. While previous studies have investigated these compounds individually, this research is demonstrating how their combined use enhances glucose uptake in insulin-resistant systems and beneficially modulates gut microbiota composition. Overall I think this is a good paper and I only have some minor comments for it. Please find below my comments with regards to your paper:

Fist of all, I believe the title is too long. Try consider shorting it. Also, I was wondering why the subjects are only males? Is there any reason behind it? If yes, include it in your Material and Methods

Line 19 – “has not been reported yet”, instead of “has not been reported”

Line 32 - Findings suggest that these phytochemicals interactions could have synergistic effects in regulating glycemia through changes in the antihyperglycaemic activity and in the gut microbiota in overweight individuals

Line 62 – remove “these” before the “over the last”

Line 68 – Several studies have indicated that efficacy is higher using a combination of compounds compared to single active constituents

Line 383 – A possible mechanism involved in these pharmacological effects could be the modulation of gut microbiota in a synergistic way.

Line 447 – “Phyla” instead of “Phylum”

 

Comments on the Quality of English Language

English language is fine, only minor revisions about the clarity of the text.

Author Response

Comment 1: I believe the title is too long. Try consider shorting it.

Response1: Our topic has been condensed to the smallest feasible length. We believe it is clear and encompasses the work's topic.

Comment 2: Also, I was wondering why the subjects are only males ? Is there any reason behind it? f yes, include it in your Material and Methods.

Response 2: Thank you for pointing this out. Previous studies showed that sex hormones like estrogen and progesterone in females can significantly affect gut microbiota composition and metabolic processes [1, 2]. In addition, hormonal variations linked to menstrual cycles can also impact immune function and gut microbiota  [3]. Therefore, studies exclusively involving males mitigate the variability resulting from hormonal fluctuations, thereby enhancing the clarity of the intervention's effects. 

References

1. Baker, J.M., L. Al-Nakkash, and M.M. Herbst-Kralovetz, Estrogen-gut microbiome axis: Physiological and clinical implications. Maturitas, 2017. 103: p. 45-53.
2. Jašarević, E., K.E. Morrison, and T.L. Bale, Sex differences in the gut microbiome-brain axis across the lifespan. Philos Trans R Soc Lond B Biol Sci, 2016. 371(1688): p. 20150122.

      3. Kundakovic, M. and D. Rocks, Sex hormone fluctuation and increased female risk for depression and anxiety disorders: From clinical evidence to molecular mechanisms. Front Neuroendocrinol, 2022. 66: p. 101010.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Interesting paper exploring the optimal mixture ratio of vitexin and iso-vi-80 texin separated from MBC to maximize the antihyperglycemic activities in an insulin resistance system.

In the analysis of penolic compunds since the authors have used HPLC it would be nice to know what the other phenolic compounds are in MBCE and their concentrations. They show it in Fig. 1A (chromatogram) but cannot see the different peaks labelled.

Please correct the following sentence

HPLC analysis 

Thermo Dionex Ultimate 3000 high-performance liquid chromatography system 130 (Thermo Fisher Scientific Inc., Massachusetts, U.S.). A C-18 column (Avantor, 250 x 4.6 mm).

Please use italics for all genus and families etc.

Parabacteroides, Ruminococcus, Roseburia, Enterocloster and Peptacetobacter

Proteus and Bu-tyricicoccus belonging to Proteobacteria and Firmicutes

Isn't the no. of feccal samples small?

 

Author Response

Comment 1: In the analysis of penolic compunds since the authors have used HPLC it would be nice to know what the other phenolic compounds are in MBCE and their concentrations. They show it in Fig. 1A (chromatogram) but cannot see the different peaks labelled.

Response 1: This study is a continuation of Maneewan et al. [4]. The aim of this study was to investigate the antihyperglycemic activities and effects on gut microbiota of vitexin and iso-vitexin. So, this study focused only on vitexin and iso-vitexin from mung bean seed coat. In Fig 1A, the chromatogram of the crude extract from the mung bean seed coat was analyzed by prep-LC, and the concentration of vitexin and iso-vitexin was rechecked in HPLC analysis (Figs. 1B and 1C). 

Comment 2: Isn't the no. of feccal samples small?

Response 2:  In vitro human gut model, three donors are sufficient for acceptance [5, 6].

References

4. Maneewan, S., P. Tangpromphan, and A. Jaree, Separation of Vitexin and Iso-vitexin from Mung Bean Seed Coats Using a Three-Zone Simulated Moving Bed (SMB). Waste and Biomass Valorization, 2021. 12.
5. Charoensiddhi, S., W.P. Chanput, and S. Sae-tan Gut Microbiota Modulation, Anti-Diabetic and Anti-Inflammatory Properties of Polyphenol Extract from Mung Bean Seed Coat (Vigna radiata L.). Nutrients, 2022. 14, DOI: 10.3390/nu14112275.

      6. Kwandee, P., et al., Efficacy of Triphala extracts on the changes of obese fecal microbiome and metabolome in the human gut model. J Tradit Complement Med, 2023. 13(2): p. 207-217.

Author Response File: Author Response.pdf