Synthesis of Nano-Selenium from Bombyx batryticatus Polypeptide and Exploring Its Antioxidant and Skin Whitening Ability

To increase the stability of selenium in nano state and further improve its antioxidant and skin whitening ability, Bombyx batryticatus polypeptide (BBPP) was prepared. The optimum synthesis conditions of Bombyx batryticatus polypeptide nano-selenium (BBPP-SeNPs) were determined by a double-peak method. BBPP-SeNPs were characterized by transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FT-IR), and particle size analysis (PSS). The 1,1-Diphenyl-2-picrylhydrazyl (DPPH), 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS), superoxide anion free radical scavenging rate, and total antioxidant capacity of BBPP, vitamin C (VC), and BBPP-SeNPs were measured for comparison. The inhibitory ability of BBPP and BBPP-SeNPs on tyrosinase was measured. Using mouse modeling, the skin whitening ability of VC and BBPP-SeNPs was measured. The results showed that the optimal conditions were obtained when the concentration of BBPP was 0.16 mg/mL, sodium selenite was 0.01 mol/L, ultrasound was carried out for 30 min, ascorbic acid was added in 0.04 mol/L, and stirring temperature was 20 °C for 4 h. The antioxidant capacity of BBPP-SeNPs has significantly improved. It can be observed that BBPP-SeNPs has obvious scavenging ability on skin-reactive oxygen species through a Reactive Oxygen Species (ROS) staining section. Through Hematoxylin–Eosin (H&E) staining, it can be proven that BBPP-SeNPs has a high security threshold.