# Cosmeceutical Potentials of _Equisetum debile_ Roxb. ex Vaucher Extracts
## 5 Conclusions  
This study explores the potential usage of _E. debile_ extracts for cosmeceuticals applications by _in vitro_ enzymatic assessments. The EF is suggested to contain the most attractive ingredients for hyperpigmentation, wrinkles, and skin aging treatments due to highly enriched total phenolic contents, exerting tyrosinase and collagenase inhibitions. The DF, HF, and EF are suggested as promising ingredients for hair loss treatment due to 5\(\alpha\)-reductase inhibitions. Additionally, compared to the recommended intake of finasteride (1 mg/day) for androgenic alopecia, the DF (1.48 \(\pm\) 0.06 mg finasteride/g) is proposed as an alternative source to naturally remediate hair loss.  
Nonetheless, further studies are required to identify and investigate the active phytochemical compositions of _E. debile_ crude extract and semi-purified fractions for better understanding of the mechanisms, pharmacodynamics, pharmacokinetics, side effects, and toxicities relating to their potential benefits as natural cosmeceutical alternatives. Cell-based assays are advised to confirm the observed _in vitro_ inhibitory activities against tyrosinase, collagenases, and 5\(\alpha\)-reductase. The direct association between _E. debile_ extracts and the cellular mechanisms could be further studied by investigating the changes in relevant gene expressions and the presences of melanin, collagen, and dihydrotestosterone. Most of the available safety information of _E. debile_ extracts has been investigated using cell lines. The preliminary cytotoxicity shown in the present study may help provide useful information for further evaluation of _in vivo_ and animal models, which would be essential for the cosmeceutical usage of _E. debile_ in topical applications for skin and hair care. Inaddition, the development of formulations providing the controlled release of plant extracts may help improve their skin biocompatibility [76].  
The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/app13031336/s1](https://www.mdpi.com/article/10.3390/app13031336/s1)]([https://www.mdpi.com/article/10.3390/app13031336/s1](https://www.mdpi.com/article/10.3390/app13031336/s1)), Table S1. Proposed phenolic compounds in _E. edible_ by LCMS qualitative identification.  
Conceptualization, P.T., J.J. and S.S.; validation, P.T., J.J. and S.S.; formal analysis, P.T., J.J. and S.S.; investigation, P.T., J.J., K.S. and S.S.; resources, P.T., J.J., S.S., R.P., A.R. and H.P.; data curation, P.T., J.J. and S.S.; writing--original draft preparation, P.T.; writing--review and editing, P.T., J.J. and S.S.; visualization, P.T. and J.J.; supervision, P.T., J.J. and S.S.; project administration, S.S.; funding acquisition, P.T., J.J., S.S., R.P., A.R. and H.P. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the Highland Research and Development Institute (Public Organization, Chiang Mai, Thailand) (grant number 5/2560 and 17/2562) and partially supported from Fundamental Fund, Chiang Mai University and Thailand Science Research and Innovation, Thailand (Grant number FRB650031/0162_FF65/047).  
This article contains an assay using donated and unused rat livers obtained from the control group of an unrelated study performed by [PERSON] et al., 2020 [51], in which the rats were euthanized, and all experiment protocols were approved by the Research Animal Care and Use Ethical Committee, Faculty of Pharmacy, Chiang Mai University, Thailand (Ethics approval no. 04/2015), in compliance with the National Institutes of Health and ARRIVE guidelines for the care and treatment of animals.  
Not applicable.  
All the related data has been provided in the manuscript.  
The article processing charge (APC) was supported by Center of Excellence for Innovation in Analytical Science and Technology for Biodiversity-Based Economic and Society (I-ANALY-S-T_B.BES-CMU), Chiang Mai University, Chiang Mai, Thailand.  
All authors declare no conflict of interest.