Fig. 4. Effect of of sericin and I-sericin or fibroin and I-fibroin on (A) procollagen type (PCOL1), (B) Elastin, and (C) MMP1 protein expression in in H₂O₂-treated HaCaT cells.

(A) PCOL1 expression of HaCaT cell with (A1) sericin or I-sericin and (A2) fibroin or I-fibroin pretreatment followed by H₂O₂; (B) Elastin expression of HaCaT cell with (B1) sericin or I-sericin and (B2) fibroin or I-fibroin pretreatment followed by H₂O₂; (C) MMP1 expression of of HaCaT cell with (C1) sericin or I-sericin and (C2) fibroin or I-fibroin pretreatment followed by H₂O₂. Different label means a significant difference between each group by one-way ANOVA. ***p < 0.005 compared to control. ^#p < 0.05, ^##p < 0.01, and ^###p < 0.005 compared with H₂O₂-treated only. ^$p < 0.05, compared to the sericin or fibroin-treated group.