In-silico and in-vitro studies of antioxidant and sun protection activities of sappan wood (Caesalpinia sappan l.)

Abstract

Sappan wood which contains brazilin and brazilein is known to have antioxidants potential because of its hydroxyl groups. The use of antioxidants in sunscreen preparations increases photoprotective activity. The purpose of this study was to evaluate the antioxidant activity of sappan wood, to determine the affinity of brazilein and brazilin for glutathione peroxidase (GPX) and catalase protein targets in silico, and describe the ability of sappan wood as an in vitro sun protection agent. The antioxidant activity was assessed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and ferrous ion chelating (FIC) assays, while the in silico test was carried out by using molecular docking with the autodock 4.2 programs. Sunscreen activity was tested by determining the sun protection factor (SPF) using the spectrophotometric method. Sappan wood was found to have very high antioxidant activity, with IC50 values of 0.88 ppm and 1.75 ppm for the ethyl acetate fraction and methanol extract, respectively, which were lower than that of ascorbic acid (7.8 ppm) in the DPPH scavenging assay.. In the FIC assay, the IC50 values were 69.46, 62.59, and 10.21 ppm for the extract, the fraction and EDTA, respectively. SPF value of the extract and the fraction of sappan wood were 17.91 and 19.53 at a 200 ppm concentration each. Brazilein and brazilin in sappan wood can induce GPX and catalase. Sappan wood has great potential to be developed as a sunscreen with a dual function as antioxidants and as UVB rays absorber.