Recycled Sericin Hydrolysates Modified by Alcalase® Suppress Melanogenesis in Human Melanin-Producing Cells via Modulating MITF

Abstract

Because available depigmenting agents exhibit short efficacy and serious side effects, sericin, a waste protein from the silk industry, was hydrolyzed using Alcalase® to evaluate its anti-melanogenic activity in human melanin-producing cells. Sericin hydrolysates consisted of sericin-related peptides in differing amounts and smaller sizes compared with unhydrolyzed sericin, as respectively demonstrated by peptidomic and SDS-PAGE analysis. The lower half-maximum inhibitory concentration (9.05 ± 0.66 mg/mL) compared with unhydrolyzed sericin indicated a potent effect of sericin hydrolysates on the diminution of melanin content in human melanoma MNT1 cells. Not only inhibiting enzymatic activity but also a downregulated expression level of tyrosinase was evident in MNT1 cells incubated with 20 mg/mL sericin hydrolysates. Quantitative RT-PCR revealed the decreased mRNA level of microphthalmia-associated transcription factor (MITF), a tyrosinase transcription factor, which correlated with the reduction of pCREB/CREB, an upstream cascade, as assessed by Western blot analysis in MNT1 cells cultured with 20 mg/mL sericin hydrolysates for 12 h. Interestingly, treatment with sericin hydrolysates for 6–24 h also upregulated pERK, a molecule that triggers MITF degradation, in human melanin-producing cells. These results warrant the recycling of wastewater from the silk industry for further development as a safe and effective treatment of hyperpigmentation disorders.

Melatonin/Sericin Wound Healing Patches: Implications for Melanoma Therapy

“…Although UVR is one of the major melanoma risk factors it is also essential for initiating vitamin D synthesis, while active forms of vitamin D also have photoprotective properties [266][267][268]. The topical treatment of large or non-resectable melanoma lesions including lentigo maligna using a combination of melatonin and sericin also shows that mitochondrial and antioxidant protection activity may lead to the development of a valuable additional strategy targeting melanoma, regarding the antibacterial properties of sericin that accelerate wound healing [269,270].…”

Hydrolyzed Conchiolin Protein (HCP) Extracted from Pearls Antagonizes both ET-1 and α-MSH for Skin Whitening

“…Although the mechanism of melanosome transferring from melanocyte to keratinocyte is still unclear, it is a quite important step to maintain and protect the healthiness of cells. Melanin deposited in the basal layer has melanogenic properties to melanocytes and inhibition on keratinocytes proliferation [ 29 , 30 ]. Meanwhile, the content of melanin in the epidermis can be decreased by excretion and reduction reactions to achieve the aim of whitening.…”

“…β -Actin was used as the internal reference in the analysis of protein expression. Samples were run as independent replicates repeated thrice for each group [ 29 , 32 ].…”

Enhancing Healing of Infected Wounds with Glycerin‐Modified Sodium Alginate/Silk Sericin Composite Film Functionalized with Polygonatum sibiricum Polysaccharide‐Capped Silver Nanoparticles

“…SS is a versatile biopolymer that has been used to create biomaterials for various applications, [13] and multiple studies have shown that SS has antioxidant, anti-inflammatory, scar-preventing, and woundhealing properties. [14][15][16] Additionally, the amino acids in SS are predominantly hydrophilic, leading to a strong ability to absorb water, which can prevent water loss and promote the proliferation of collagen. [17] Silver nanoparticles (AgNPs) have been shown to exert a strong killing effect on a variety of pathogenic microorganisms, such as E. coli and S. aureus, and their use does not lead to resistance.…”

“…Another potential additive to wound‐healing polymers is silk sericin (SS), which wraps around the core fibroin fibers that give silk its structural properties. SS is a versatile biopolymer that has been used to create biomaterials for various applications, [13] and multiple studies have shown that SS has antioxidant, anti‐inflammatory, scar‐preventing, and wound‐healing properties [14–16] . Additionally, the amino acids in SS are predominantly hydrophilic, leading to a strong ability to absorb water, which can prevent water loss and promote the proliferation of collagen [17] …”