## 5 Conclusions  
Our study showed that _S. deserticola_ JD052 extracts have hair follicle-inductive properties in HDP cells. Especially, the transcription activity of \(\beta\)-catenin in HE-treated HDP cells was higher than that of PE-treated cells. As mentioned earlier, our results showed that HE increased the phosphorylation level of AKT and subsequently GSK3\(\beta\), which is a key modulator of \(\beta\)-catenin signaling. However, the phosphorylation levels of MAPK, which we further examined, showed no change by HE treatment, even though these signaling pathways are also important in hair growth and hair follicle morphogenesis. HE also enhanced \(\beta\)-catenin stabilization and induced translocation into the nucleus via the inhibition of \(\beta\)-catenin phosphorylation. Moreover, DP signature genes, including _ALP, VCAN, WNT5A, VEGF, NOG, IGF1, FGF2, LEF1_, and FGF7, were upregulated in HE-treated HDP cells. The conditioned media from HE-treated HDP cells contained VEGF, IGF1, FGF2, and FGF7. The treatment of conditioned media increased the migration status of HaCaT keratinocytes and the gene expression of intracellular _VEGF_, _IGF1_, and _IL-1a_. These results suggest that HE regulates the \(\beta\)-catenin signaling via facilitating AKT/GSK3\(\beta\) signaling pathways in HDP cells, and consequently modulates the secretion of autocrine and paracrine factors and the growth of hair follicles via exerting effects on DP cells and the surroundings of epithelial components. In summary, this study may demonstrate the hair-inductive properties of _S. deserticola_ JD052 as a new natural resource of alopecia treatment that probably solve the adverse effects of general therapeutic drugs. However, it is important to acknowledge that our study has an inherent limitation as it was performed using in vitro cell models. Hence, experiments in animal models and human clinical investigation are required in further research for validation of the capability of HE in ameliorating alopecia. Nevertheless, the novelty of this research lies in demonstrating that strategic manipulation of the cultivation method can enhance the extract's overall efficacy by increasing the production of specific, potentially synergistic compounds, including pheophorbide A, as well as a compound with an \(m/z\) of 277.2192 and an elemental composition of C\({}_{18}\)H\({}_{30}\)O\({}_{2}\), likely corresponding to linoleicidic acid or linoleic acid. This has important implications for optimizing the extraction and application of bioactive compounds from _S. deserticola_ JD052 in hair growth promotion, extending beyond the sole reliance on lolioilide as the primary active component. These findings provide valuable insights for the future development of microalgae-based bioactive materials in hair growth applications. The following supporting information can be downloaded at [[https://www.mdpi.com/article/10.3390/app15042015/s1](https://www.mdpi.com/article/10.3390/app15042015/s1)]([https://www.mdpi.com/article/10.3390/app15042015/s1](https://www.mdpi.com/article/10.3390/app15042015/s1)), Figure S1: Effects of _S. deserticola_ JD052 extracts on the proliferative capacity of 3D-cultured HDP cells. HDP cells were treated with 10, 50, and 100 \(\upmu\)g/mL of (a) PE and (b) HE for 48 h. The spheroid-forming ability of 3D-cultured HDP cells was evaluated using the WST-1 assay. Figure S2: Luciferase reporter assay showing the transcriptional activity of the TCF/LEF promoter in response to _S. deserticola_ JD052 extracts. 293T cells were treated with 5 and 10 \(\upmu\)g/mL of HE and PE for 48 h. The transcriptional activity of the TCF/LEF promoter was measured by luminescence and calibrated by \(\beta\)-galactosidase activity. Figure S3: HDP cells were co-treated with 100 \(\upmu\)g/mL of HE and with or without 20 \(\upmu\)M LY294002 for 24 h. Intracellular protein expression and phosphorylation levels of AKT, GSK3\(\beta\), \(\beta\)-catenin, and FGF2 were determined using Western blot. \(\beta\)-Actin served as a loading control for total cellular protein.