Biomaterial and Tissue Engineering Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati-781039, Assam, India.
Photochem Photobiol Sci. 2019 Oct 9;18(10):2497-2508. doi: 10.1039/c9pp00059c.
Ultraviolet radiation (UVR)-induced redox imbalance in melanocytes triggers the activation of tyrosinase that results in melanogenesis and its related skin disorders. Supplementation of biological reductants or anti-tyrosinase compounds inhibits such melanogenesis. Silk sericin (SS), a globular protein, is known to possess antioxidant and anti-tyrosinase activities along with other biological attributes. However, its inhibitory activity against UVR-induced melanogenesis has yet to be explored. In the current study, we have scientifically explored the inhibitory activity of SS against UVR-induced melanogenesis. Anti-tyrosinase activity of SS was assessed using mushroom tyrosinase, showing that Antheraea assamensis sericin (AAS) and Philosamia ricini sericin (PRS) inhibited 50% of its activity. Inhibitory activity of SS against UVR-induced melanogenesis was assessed by measuring the cellular melanin content, intracellular tyrosinase activity, and reactive oxygen species (ROS) levels in mouse melanoma. SS pretreatment significantly reduced cellular melanin and ROS production in UV irradiated melanocytes compared with SS untreated cells. AAS treatment before UVA or UVB irradiation significantly inhibited tyrosinase activity. Rheological studies showed that the skin care formulation prepared by the addition of AAS to the basic formulation minimally affected its flow properties. Altogether, our results validate that AAS efficiently inhibited UVR-induced melanogenesis and it could be used as a potential antioxidant molecule in skin care cosmeceutics.
紫外线辐射（UVR）引起的黑素细胞氧化还原失衡会触发酪氨酸酶的激活，导致黑色素生成及其相关的皮肤疾病。生物还原剂或酪氨酸酶抑制剂的补充可以抑制这种黑色素生成。丝胶（SS）是一种球状蛋白，已知具有抗氧化和抗酪氨酸酶活性以及其他生物学特性。然而，其对 UVR 诱导的黑色素生成的抑制活性尚未得到探索。在本研究中，我们从科学角度探索了 SS 对 UVR 诱导的黑色素生成的抑制活性。通过蘑菇酪氨酸酶评估 SS 的抗酪氨酸酶活性，结果表明，阿萨姆野蚕丝胶（AAS）和蓖麻蚕丝胶（PRS）抑制了其 50%的活性。通过测量细胞黑色素含量、细胞内酪氨酸酶活性和活性氧（ROS）水平来评估 SS 对 UVR 诱导的黑色素生成的抑制活性。与未经 SS 处理的细胞相比，SS 预处理可显著降低 UV 照射的黑素细胞中的细胞黑色素和 ROS 生成。在 UVA 或 UVB 照射前用 AAS 处理可显著抑制酪氨酸酶活性。流变学研究表明，在基本配方中添加 AAS 制备的护肤品配方对其流动性能的影响最小。总之，我们的结果验证了 AAS 可有效抑制 UVR 诱导的黑色素生成，可作为皮肤护理化妆品中的潜在抗氧化分子。
