Radiofrequency Irradiation Mitigated UV-B-Induced Skin Pigmentation by Increasing Lymphangiogenesis

Dermal macrophages containing melanin increase skin pigmentation since dermal melanin removal is slower than epidermal melanin removal. Lymphatic vessels are also involved in melanin clearance. We evaluated whether radiofrequency (RF) irradiation induced an increase in HSP90, which promotes lymphangiogenesis by activating the BRAF/MEK/ERK pathway and decreasing tyrosinase activity, in the UV-B exposed animal model. The HSP90/BRAF/MEK/ERK pathway was upregulated by RF. Tyrosinase activity and the VEGF-C/VEGFR 3/PI3K/pAKT1/2/pERK1/2 pathway, which increase lymphangiogenesis, as well as the expression of the lymphatic endothelial marker LYVE-1, were increased by RF. Additionally, the number of melanin-containing dermal macrophages, the melanin content in the lymph nodes, and melanin deposition in the skin were decreased by RF. In conclusion, RF increased HSP90/BRAF/MEK/ERK expression, which decreased tyrosinase activity and increased lymphangiogenesis to eventually promote the clearance of dermal melanin-containing macrophages, thereby decreasing skin pigmentation.

AMINO ACID COMPOSITION AND ANTI-TYROSINASE ACTIVITY OF METABOLITES FROM EDIBLE Pleurotus SPECIES FOR THEIR NUTRITIONAL AND THERAPEUTIC POTENTIAL

Mushrooms are being extensively researched due to their nutritional value and medicinal importance. The genus Pleurotus is the second most cultivated mushroom and is known for its high nutritional value, therapeutic properties, taste, flavor, as well as their application in biotechnology and environmental study. Also, tyrosinase is prevalent in most living organisms. The enzyme catalyzes the oxidation of monophenols to ortho-quinones in a two-step reaction process. This study was aimed to assess the amino acid composition and anti-tyrosinase activity of metabolites obtained from edible Pleurotus species. Assessment of the nutritional content and inhibitory studies of mushroom tyrosinase produced from four Pleurotus strains was carried out using high-performance liquid chromatography (RP-HPLC). The results of the study showed that seventeen different amino acids were identified in the crude and partially purified protein metabolites. Also, the crude extract metabolite had the highest quantity of amino acids than the partially purified. The highest and lowest amino acids value Glutamic acid (1343.26 µmol/mL) and valine (0.34 µmol/mL). The anti-tyrosinase inhibition studies of the four Pleurotus strains showed varying results from significantly inhibitory effects to slightly inhibitory effects on mushroom tyrosinase. The highest inhibition was 14.86% (Pleu-W), while the lowest inhibition was 51.42% (Plof-30) respectively. The high point of this study is that the Pleurotus species contains a significant number of amino acids and also, they possess good anti-tyrosinase activity. Therefore, these are a good source of nutritional and therapeutic metabolites and these can be explored further for their nutritional and medicinal importance to man.

A Study on the Skin Whitening Activity of Digesta from Edible Bird’s Nest: A Mucin Glycoprotein

Edible bird’s nest (EBN) is an unusual mucin glycoprotein. In China, it is popular among consumers due to its skin whitening activity. However, the relationship between protein, sialic acid, and the whitening activity of EBN after digestion is still unclear. In the present work, the whitening activity (antioxidant activity and tyrosinase inhibitory activity) of digested EBN were studied by HepG2 and B16 cell models. The dissolution rate of protein and sialic acid was 49.59% and 46.45% after the simulated digestion, respectively. The contents of free sialic acid and glycan sialic acid in EBN digesta were 17.82% and 12.24%, respectively. HepG2 cell experiment showed that the digested EBN had significant antioxidant activity, with EC50 of 1.84 mg/mL, and had a protective effect on H2O2-induced oxidative damage cells. The results of H2O2-induced oxidative damage showed that the cell survival rate increased from 40% to 57.37% when the concentration of digested EBN was 1 mg/mL. The results of the B16 cell experiment showed that the digested EBN had a significant inhibitory effect on tyrosinase activity, and the EC50 value of tyrosinase activity was 7.22 mg/mL. Cell experiments showed that free sialic acid had stronger antioxidant activity and tyrosinase inhibitory activity than glycan sialic acid. The contribution rate analysis showed that protein component was the main antioxidant component in digestive products, and the contribution rate was 85.87%; free sialic acid was the main component that inhibited tyrosinase activity, accounting for 63.43%. The products of the complete digestion of EBN are suitable for the development of a new generation of whitening health products.

Attenuation Effect of Radiofrequency Irradiation on UV-B-Induced Skin Pigmentation by Decreasing Melanin Synthesis and through Upregulation of Heat Shock Protein 70

Excess melanin deposition in the skin causes cosmetic problems. HSP70 upregulation decreases microphthalmia-associated transcription factor (MITF) expression, which eventually decreases tyrosinase activity and melanogenesis. Ultraviolet (UV) radiation upregulates p53, which increases the melanocortin receptor (MC1R) and MITF. Furthermore, HSP70 decreases p53 and radiofrequency irradiation (RF) increases HSP70. We evaluated whether RF increased HSP70 and decreased p53, consequently decreasing the MITF/tyrosinase pathway and melanogenesis in UV-B radiated animal skin. Various RF combinations with 50, 100, and 150 ms and 5, 10, and 15 W were performed on the UV-B radiated mouse skin every 2 d for 28 d. When RF was performed with 100 ms/10 W, melanin deposition, evaluated by Fontana–Masson staining, decreased without skin crust formation in the UV-B radiated skin. Thus, we evaluated the effect of RF on decreasing melanogenesis in the HEMn and UV-B radiated skin at a setting of 100 ms/10 W. HSP70 expression was decreased in the UV-B radiated skin but was increased by RF. The expression of p53, MC1R, and MITF increased in the UV-B radiated skin but was decreased by RF. The expression of p53, MC1R, and MITF increased in the α-MSH treated HEMn but was decreased by RF. The decreasing effects of RF on p53, MC1R, CREB and MITF were higher than those of HSP70-overexpressed HEMn. The decreasing effect of RF on p53, MC1R, CREB, and MITF disappeared in the HSP70-silenced HEMn. MC1R, CREB, and MITF were not significantly decreased by the p53 inhibitor in α-MSH treated HEMn. RF induced a greater decrease in MC1R, CREB, and MITF than the p53 inhibitor. Therefore, RF may have decreased melanin synthesis by increasing HSP70 and decreasing p53, thus decreasing MC1R/CREB/MITF and tyrosinase activity.

Camellia japonica Essential Oil Inhibits α-MSH-Induced Melanin Production and Tyrosinase Activity in B16F10 Melanoma Cells

Essential oils are aromatic oils extracted from the leaves, stems, peels, petals, and roots of aromatic plants grown in nature or grown in organic methods and have various medical effects as natural substances. The essential oil extracted from Camellia japonica seeds exhibits various functional properties; however, its tyrosinase inhibitory activity has not been investigated extensively. This study is performed to investigate the chemical composition and tyrosinase inhibitory activity of Camellia japonica seed essential oil (CJS-EO). Hexamethylcyclotrisiloxane (42.36%) and octamethylcyclotetrasiloxane (23.28%) are the two primary components of CJS-EO, as identified via gas chromatography-mass spectrometry. The inhibitory activities of CJS-EO and positive control arbutin are further evaluated against mushroom tyrosinase. The results show that CJS-EO and arbutin inhibit tyrosinase activity. Moreover, CJS-EO significantly inhibits melanogenesis in the α-melanocyte-stimulating hormone-treated group, and a significant amount of melanin is suppressed. To ascertain the cause of the CJS-EO tyrosinase inhibitory effect and melanin reduction effect, genetic and protein analyses are performed. Based on our results, we tentatively conclude that CJS-EO can inhibit melanocytes from harmful factors such as tyrosinase-related protein. These results demonstrate that CJS-EO possesses potent antityrosinase activity and may be a good skin-whitening agent.