Stimulatory effects of Lycium shawii on human melanocyte proliferation, migration, and melanogenesis: In vitro and in silico studies

Abstract

There is no first-line treatment for vitiligo, a skin disease characterized by a lack of melanin produced by the melanocytes, resulting in an urgent demand for new therapeutic drugs capable of stimulating melanocyte functions, including melanogenesis. In this study, traditional medicinal plant extracts were tested for cultured human melanocyte proliferation, migration, and melanogenesis using MTT, scratch wound-healing assays, transmission electron microscopy, immunofluorescence staining, and Western blot technology. Of the methanolic extracts, Lycium shawii L. (L. shawii) extract increased melanocyte proliferation at low concentrations and modulated melanocyte migration. At the lowest tested concentration (i.e., 7.8 μg/mL), the L. shawii methanolic extract promoted melanosome formation, maturation, and enhanced melanin production, which was associated with the upregulation of microphthalmia-associated transcription factor (MITF), tyrosinase, tyrosinase-related protein (TRP)-1 and TRP-2 melanogenesis-related proteins, and melanogenesis-related proteins. After the chemical analysis and L. shawii extract-derived metabolite identification, the in silico studies revealed the molecular interactions between Metabolite 5, identified as apigenin (4,5,6-trihydroxyflavone), and the copper active site of tyrosinase, predicting enhanced tyrosinase activity and subsequent melanin formation. In conclusion, L. shawii methanolic extract stimulates melanocyte functions, including melanin production, and its derivative Metabolite 5 enhances tyrosinase activity, suggesting further investigation of the L. shawii extract-derived Metabolite 5 as a potential natural drug for vitiligo treatment.

Cyclocurcumin, a Minor Curcuminoid, Is a Novel Candidate for Hypopigmentary Skin Disorders with Melanogenesis-Stimulating Capacity

“…Notably, the culture of HEMn-LP cells in PMA-free HMGS (HMGS-2 [116]) causes cells to synthesize lower melanin and remain bipolar with low dendrite number [117,118] and was employed in some of the previous studies that reported on compounds that stimulated melanogenesis in primary human melanocytes cultured with HMGS-2 supplement [119][120][121]. The use of HMGS-2 might have been a better choice to study the isolated effects of CYC in promoting pigmentation; however, previous reports have utilized HMGS in their experiments with compounds that stimulated melanogenesis [122,123]; hence, the use of HMGS is acceptable. Additionally, in our earlier studies that reported on stimulators of melanogenesis, we have continued to use HMGS medium only [39,75].…”

Rational design of an N-terminal cysteine-containing tetrapeptide that inhibits tyrosinase and evaluation of its mechanism of action

“…Melanin is a pigment produced in plants, microorganisms, and animals ( Alghamdi et al, 2023 ). In skin, its role is to protect the skin from ultraviolet (UV) radiation damage ( Shen et al, 2019 ; Nazir et al, 2022 ).…”