Study on the Regulation and Mechanism of the Vanadium Substituted Polyoxometalates of H₆[P₂Mo₁₈O₆₂] on Melanogenesis of Mouse Melanoma Cell B16

Abstract

Melanin is the main cause of pigmentation in human skin, eyes and hair. In order to study the effects of polyoxometalates on the tyrosinase activity and melanin content of B16 mouse melanocytes, five polyoxometalates with Dawson structure with different vanadium substitutions were synthesized. Taking B16 mouse melanoma cells as a model, which was divided into blank group, control group and polyoxometalates experiment group (12.5, 25, 50, 100, 200 μmol/L), the cell viability was detected by thiazolyl blue (MTT) method, and the diphenyl picryl hydrazinyl (DPPH) free radical scavenging ability and the melanin content and tyrosinase activity in B16 melanoma cells were determined by enzyme labeling method. Finally, molecular docking was used to simulate the binding mechanism of polyoxometalate and tyrosinase. The results of the study showed that two phosphomolybdic acids (H7[P2Mo17VO62] and H8[P2Mo16V2O62]) are highly effective melanin production inhibitors, and the best inhibitory rates of melanin synthesis at a concentration of 200 μmol/L are 74.40% and 75.14%, respectively, which have an effect on the cell. The inhibitory rates of tyrosinase activity were 35.71% and 40.00%. With the increase of the number of vanadium atoms substituted, the two inhibitory activities gradually decreased. MTT reduction experiments show that H7[P2Mo17VO62] and H8[P2Mo16V2O62] are not toxic to cells, and the cell viability is greater than 80%. Both polyoxometalates (POMs) have strong DPPH scavenging ability, with IC50 of 1.683 and 2.800 mg/mL, respectively. Molecular docking simulation proved that all five polyoxometalates can form stable complexes with tyrosinase, and the main force of the combination are non-covalent bonds such as van der Waals forces and hydrogen bonds. In addition, the docking score is less than -146 kJ/mol. Based on the above research, H7[P2Mo17VO62] and H8[P2Mo16V2O62] can effectively inhibit the production of melanin in B16 mouse melanoma cells. The mechanism is related to the inhibition of tyrosinase activity. We believe that they are promising candidates for the development of safe cosmetics.

Regulation of Tendon-bone Related Multiple Cells by Chemical Ions Released from Mo-containing Silicate Bioceramics★

“…例如, 在先前的 研究中, 我们发现锂掺杂介孔硅酸盐生物玻璃降解产生 的离子产物可以通过刺激 Wnt 信号通路促进骨髓间充 质干细胞的增殖和成骨分化, 同时可以通过激活自噬保 护软骨细胞 [8] . 更为重要的是, 越来越多的研究表明, 生物陶瓷材料所产生的化学信号能够调节不同类型细 胞的细胞行为 [9][10][11][12][13][14][15] . Lin 等 [16] 发现锶掺杂的硅酸钙陶瓷降 解产生的锶(Sr)、钙(Ca)、硅(Si)化学信号能够促进人脐 静脉内皮细胞的成血管分化, 同时能够通过刺激骨髓间 充质干细胞的细胞外信号相关激酶和 p38 信号通路促进 成骨分化.…”