Explore the antioxidative and tyrosinase inhibitory activity of green sericin resources from different fibroin-deficient silkworm varieties

Sericin has garnered substantial interest in biomedicine, cosmetics, and functional food. Fibroin-deficient mutant cocoons yield sericin of higher-quality with more promising application prospects compared to their wild-type counterparts. However, current studies on sericin’s bioactivities are primarily focus on wild-type sources, posing a challenge in obtaining high-quality sericin. To delve deeper into the potential of sericin from mutant silkworms, three varieties of fibroin-deficient mutant silkworm cocoons were selected. Employing high-temperature and high-pressure (HTHP) methodologies facilitated the extraction of sericin from these cocoons. After hydrolyzing the three types of sericin with trypsin, their hydrolysates showed impressive antioxidant capacity. At the concentration of 3.2 mg/mL for each type of hydrolysate, more than 65% of DPPH free radicals and 90% of ABTS free radicals were cleaned. Moreover, they can inhibit at least 40% of tyrosinase and exert a remarkable inhibitory impact on tyrosinase activity. Importantly, the sericin hydrolysates can significantly protect cell against oxidative damage. Additionally, these three types of sericin have significant effects in inhibiting melanin production. The observed variations in bioactivities across these diverse sericin varieties are particularly fascinating.