Anti-elastase, anti-tyrosinase, and anti-oxidant of Rubus fraxinifolius stem methanolic extract

Introduction: Some Rubus were reported had anti-skin aging activity. Rubus fraxinifolius was one of Rubus genus which lives in Indonesian highland. Objective: This study was to examine elastase, tyrosinase, and oxidant inhibitory activity of R. fraxinifolius stem (RFS) extract. Methods: Extraction was done by a Soxhlet apparatus using methanol as solvent. Elastase inhibition activity was determined, which based on the formation of p-nitroaniline. Tyrosinase inhibition activity evaluated based on inhibition of mushroom tyrosinase by the sample with L-DOPA as substrate. The activity of antioxidant was determined using the DPPH radical scavenger method. LC-MS was used for prediction of naturally occurring phytochemicals. Results: The RFS extract yield was 9.03 %. The RFS extract revealed inhibition activity against elastase and tyrosinase with IC₅₀ 128.85 ppm, and 155.19 ppm, respectively. DPPH radical scavenging activity gave IC₅₀ 63.04 ppm. Total phenolic content of the extract was 387.99+3.21 mg GAE/g extract. The LC-MS analysis showed the presence of at least 13 different organic compounds in RFS extract, which might contribute to the bioactivity. Conclusion: Therefore, this experiment further proved that RFS extract might be useful as a natural product ingredient of anti-photoaging skincare products because of its ability to inhibit elastase, tyrosinase, and as an antioxidant.