Inhibitory Effect of Ficin Derived from Fig Latex on Inflammation and Melanin Production in Skin Cells

Abstract

Ficin isolated from fig tree latex is a unique enzyme having both protease and peroxidase activities. Recently, it has been revealed that peroxidase activity of ficin is about 60% or more at pH 4.5 ∼ 5.0 which is the pH of normal skin. However, other efficacy studies and mechanisms of action about ficin are not well known. Thus, the objective of the present study was to investigate the anti-oxidation, anti-inflammatory, and whitening effects of ficin through in vitro studies. First, the antioxidant activity of ficin was confirmed by DPPH and H2O2 assays. The DPPH radical scavenging activity was about 78.7% level of L-ascorbic acid (vitamin C) at the same concentration of 1,000 µg/mL and the H2O2 scavenging activity was about 72.3 ± 4.1% of L-ascorbic acid. Second, ficin suppressed NO production in LPS-stimulated RAW264.7 cells in a concentration-dependent manner (at concentration of 10, 25, 50, and 100 µg/mL, NO production was 90.5 ± 0.5%, 77.3 ± 0.5%, 67.9 ± 1.1%, and 59.6 ± 0.5%, respectively, compared to the control). Ficin could inhibit mRNA and protein expression levels of inducible NO synthase (iNOS), implying its anti-inflammatory activity. To evaluate inhibitory effect of ficin on inflammation signaling pathway, we determined whether ficin could inhibit phosphorylation of inflammatory signaling proteins such as IκB and NF-κB as well as MAPKs (ERK, JNK, p38). Third, we verified the whitening effect of ficin. After B16F10 cells (mouse melanoma cells) were treated with α-MSH (200 nM) along with ficin at concentrations of 0, 5, 10, and 20 µg/mL for 96 h, melanin contents were increased to 227.1 ± 5.9% by α-MSH alone, but decreased to 197.9 ± 2.4, 107.3 ± 0.9, and 105.2 ± 0.9% in the presence of ficin at 5, 10, and 20 µg/mL, respectively. These results suggest that ficin could be used as a good cosmetic material with enzyme stabilization and cell penetration technology in the future.