A prepared platelet-rich plasma extract, namely Self-Growth Colony, inhibits melanogenesis by down-regulating microphthalmia-associated transcription factor in skin melanocyte

Mechanism of skin whitening through San-Bai decoction-induced tyrosinase inhibition and discovery of natural products targeting tyrosinase

Melanin deposition is the main cause of skin darkening, which can lead to severe physical and psychological distress, necessitating the development of approaches for preserving skin health and fairness. Tyrosinase (TYR) is the rate-limiting enzyme in melanin synthesis, and its activity directly determines the degree of melanin accumulation in the skin, which in turn affects skin color. Currently, TYR inhibitors derived from natural products are widely used for skin whitening. San-Bai decoction (SBD) is effective for skin whitening and softening, but its mechanism of action, efficacy and high efficiency TYR inhibitors for skin whitening remain poorly understood. Here, we employed systems biology and network pharmacology to analyze the active compounds and targets of SBD, using the follow databases: TCMIP, TCMID, and BATMAN-TCM. Construct a molecular network centered on the regulation of TYR by SBD in skin whitening, using STRING database and cytoscape. Enrichment analysis using KOBAS database and ClusterProfiler. Virtual screening of candidate TYR inhibitors using Molecular Operating Environment software and Amber 18 software. SBD may act through tyrosine metabolism, melanogenesis, and other signaling pathways to regulate TYR activity and inhibit melanogenesis. We identified TYR and ESR1 as possible key targets for the whitening effect of SBD and screened out pentagalloylglucose, 1,3,6-tri-O-galloyl-beta-D-glucose, 1,2,4,6-tetragalloylglucose, and liquiritigenin 4',7-diglucoside as inhibitors of TYR, in addition to glycyrrhizic acid, pachymic acid methyl ester, nicotiflorin, gamma-sitosterol, and isoliensinine as inhibitors of ESR1. We also performed virtual drug screening of a library of natural small-molecule compounds (19,505 in total) and screened out lycopsamine, 2-phenylethyl b-D-glucopyranoside, and 6-beta-hydroxyhyoscyamine as inhibitors of TYR. We identified natural compounds with the potential for skin whitening through inhibition of TYR, thus advancing research on SBD and its applications.

Scutellarin potentiates the skin regenerative function of Self Growth Colony, an optimized platelet-rich plasma extract, in cultured keratinocytes through VEGF receptor and MAPK signalling

BACKGROUND

Migration of keratinocyte plays an essential role in wound healing. The proprietary platelet-rich plasma from human blood, named as Self-Growth Colony (SGC), functions in stimulating migration of wounded keratinocytes. And the growth factors, including VEGF, being enriched in SGC could account for this function. Scutellarin, an active phytochemical from root of Scutellaria barbata D. Don, has been proposed to have various pharmacological functions; however, the activity in epidermal skin cells is yet to be explored. Here, the role of scutellarin in potentiating the functionality of SGC to promote the regeneration of wounded keratinocyte was probed.

METHODS

Molecular docking and ultrafiltration-based LC-MS were performed to verify the binding between scutellarin and VEGF, which potentiated the VEGF-mediated functions. Scratch assay, performed on cultured keratinocytes, was to analyse the treatments of SGC and scutellarin in the process of wound healing. Western blot analysis was to confirm the involvement of signalling cascades in observed effects.

RESULTS

We have identified the binding of scutellarin with VEGF. The binding accounted for the potentiation role of scutellarin in skin regeneration, as triggered by SGC. The co-treatment of scutellarin and SGC onto scratched keratinocyte cultures was able to enhance the process of wound healing, i.e. scutellarin showed a potentiating effect to SGC. In addition, the potentiation of scutellarin was shown to be mediated by phosphorylation of VEGF receptor 2 (VEGFR2) and mitogen-activated protein kinase (MAPK) signalling.

CONCLUSION

These findings support the application of scutellarin as an enhancing agent in potentiating the SGC-mediated wound healing.