# Cosmeceutical Potentials of _Equisetum debile_ Roxb. ex Vaucher Extracts
## 4 Discussion  
Phytochemicals have benefits to human health. However, their extractabilities are influenced by chemical structures. Therefore, extraction methods must be optimized to efficiently isolate compounds of interest. Macerations were previously used to obtain extracts from _E. debile_. Nonetheless, they may have limited usage due to the low content of bioactive compounds and less bioactivities as a result. Therefore, this study is the first report that aims to demonstrate the application of a solvent-solvent extraction technique to sequentially isolate phytochemicals by polar characteristics to obtain semi-purified fractions of _E. debile_. The macerated ethanolic crude extract of _E. debile_ was successively partitioned by various solvents with increasing polarities as follows: hexane, dichloromethane, ethyl acetate, and methanol (Figures 1-3). Among these fractions, HF and DF had noticeably higher extractable yields than those of EF and MF (Figure 3). The highest extract yield was obtained by using hexane (43.64 \(\pm\) 1.80%). Additionally, the extract yield of HF was higher than that of DF by 1.82-fold. Based on the chemical polarities, each fraction should exhibit three main characteristics that are distinct from the crude extract. First, each fraction should reflect higher refined compound suites encompassing several chemicals with similar polarities than crude extract. Second, the quantities of particular compounds should be more concentrated in certain fractions than those of crude extract and other fractions. Third, individual fractions should represent a collection of phytochemicals that comprise the total composition of the crude extract. Therefore, this study may suggest that the majority of compounds in CE possessed the non-polar indices similarly to hexane, following by the compounds with moderate polarity indices similarly to dichloromethane. On the contrary, the extract yield of EF was the lowest among fractions and lower than that of MF by 2.72-fold. Taken together, the sequential partitioning method may enable the isolation of _E. debile_ extracts with distinguishable phytochemicals. However, further experiments are required to identify the extracted compounds and examine the compound enrichments. The extraction yield is not only affected by solvent polarity but also other factors including growth conditions, time of harvesting, storage conditions, and extraction temperature. These factors should also be taken into consideration when designing and optimizing extraction methods. _E. debile_ extracts were further investigated for phenolic, silicon, and cosmeceutical potentials. The total phenolic contents (TPC) of _E. debile_ extracts were shown in Figure 5. EF contained the highest TPC among fractions and was also higher than that of the crude extract by 2.19-fold. The TPC values obtained from DF and HF were comparative and the lowest among fractions. EF exhibited higher TPC than those of DF and HF by 8.98 and  
Figure 11: Cell viability study of _E. debile_ extracts on skin fibroblast cell line (SF-TY) using MTT assay. ‘-v Successive partition of crude extract (CE) (10.45 \(\pm\) 1.20 g) into hexane fraction (HF), dichloromethane fraction (DF), ethyl acetate fraction (EF), methanol fraction (MF), and methanol insoluble residue (MR). All data are presented as mean \(\pm\) SD of triplicates. 11.1-fold, respectively. Additionally, MF displayed higher TPC than those of DF and HF by 2.22 and 2.75-fold. This indicates that most phenolic compounds in _E. debile_ possessed moderate polarity characteristics in molecules predominantly close to and exclusively extractable by ethyl acetate. Two flavonoids, quercetin and quercetin-3-O-\(\alpha\)-D-rhamnopyranoside, were previously isolated from the ethyl acetate extract of _E._ debile [55]. Therefore, these two compounds may be present in EF in this study. In addition, the phenolic compounds shown in Supplementary Table S1 were qualified from CE of _E. debile_ by LCMS (Q-TOF) analysis.