Effect of Scenedesmus deserticola JD052 Extracts on Hair Inductivity by Regulating the AKT and GSK3β/β-Catenin Signaling Pathways in Human Dermal Papilla Cells

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

I congratulate the authors on their paper entitled: ‘Effect of Scenedesmus deserticola JD052 Extracts in Hair Inductivity by Regulating the AKT and GSK3β/β-catenin Signalling Pathway in Human Dermal Papilla Cells’. I have some clarifications to make:

. Methodology

- Lack of comprehensive biological models: Although the work focuses on in vitro models, the exclusive use of human dermal papilla cells (HDP) and HaCaT poses a limit to the generalisability of the results. The lack of animal or human models to validate efficacy limits the clinical impact.

- Insufficient controls: The comparison between extracts from photoautotrophic (PE) and heterotrophic (HE) cultures is interesting, but lacks an alternative negative control group, such as a pure solvent treatment or a different microalgae extract.

- Choice of concentrations: The maximum concentration of 100 μg/mL may not represent a physiologically relevant threshold. It would be useful to include tests at lower concentrations to determine a more realistic therapeutic range.

- Limited statistical analysis: Although statistical tests (e.g. ANOVA) are indicated, specific details on sample sizes and criteria for statistical power are lacking. This reduces transparency on the reliability of the data presented.

. Experimental Results

- Effects on β-catenin signal:

o Although the data demonstrate an increase in the stability of β-catenin and its nuclear translocation, no experiments were included to confirm the direct functionality of β-catenin in the regulation of target genes related to hair follicle growth. For example, β-catenin knockdown experiments would have clarified whether β-catenin was essential for the observed effect.

3. Discussion and Conclusions

- Generalisability of conclusions:

o The discussion emphasises the potential of HE extract for hair growth, but the evidence is limited to an in vitro context. The lack of preclinical models makes the conclusions

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

In this study, the authors aimed to investigate the effects of S. deserticola JD052 extract on regulating hair inductivity through the activating β-catenin signaling via facilitating AKT/glycogen synthase kinase 3β (GSK3β) signaling pathway in human dermal papilla (HDP) cells. Our study showed that S. deserticola JD052 extracts had hair follicle-inductive properties in HDP cells, which HE may enhance hair growth inductivity via AKT/β-catenin signaling.

Comments:

The reviewer has some concerns as follows:

1.         It has been demonstrated that Loliolide from Scenedesmus deserticola JD052 possesses the anti-aging properties (Cho et al., 2023; doi: 10.4014/jmb.2304.04044.). Loliolide has also been found to function in the hair growth inductivity of HDP cells via the AKT/β-catenin signaling pathway (Lee et al., 2019; https://doi.org/10.4014/jmb.1908.08018). In fact, the methods, results, data presentation, and conclusions of this manuscript are very similar to those study by Lee et al. (2019). Therefore, the findings of this manuscript seem to be predictable. Moreover, the effects of S. deserticola JD052 extract on air growth inductivity of HDP cells do not appear to be any more effective than the Loliolide. The author should state/discuss the purpose and benefit of using the S. deserticola JD052 extract and the comparison with the Loliolide.

2.         Why two forms of extracts obtained from both photoautotrophic (PE) and heterotrophic (HE) cultures were used? It needs to be clearly explained in the Introduction or Methods.

3.         In the Methods - Statistical analysis, it described “All data were analyzed using a two-tailed Student’s t-test”. However, the description of “Significance was determined using a one-way ANOVA followed by Tukey’s test” was indicated in the figure legends. It needs to be checked and revised.

4.         In Figure 1(b) and 2(b), the results for spheroid size are unconvincing. It is difficult to observe from these images that the test substance has any effect on spheroid size compared to control group.

5.         In Figure 5(a), why is there no serum-free DMEM group? In Figure 5(b)(c), the three groups for serum-free DMEM, CM0 and CM100 are compared.

6.         Overall, in the present state, the presented results cannot support the conclusions.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

This new version of the Article is complete.

Reviewer 2 Report

Comments and Suggestions for Authors

This revised manuscript has a great improvement and the reviewer has no further comments.