In Vitro Evaluation of Antioxidant Activity and Tyrosinase Inhibition of Syzygium polyanthum Extract

Abstract

Natural plant-based compounds have attracted increasing attention as potential sources of antioxidant and skin-related bioactive agents. Syzygium polyanthum (bay leaf) contains various phenolic compounds that may contribute to antioxidant and tyrosinase inhibitory activities. This study aimed to evaluate the antioxidant activity and tyrosinase inhibitory potential of Syzygium polyanthum extract in vitro. Antioxidant activity was evaluated using the DPPH radical scavenging assay at concentrations of 200–800 ppm, while tyrosinase inhibitory activity was assessed using a dopachrome-based enzymatic method at concentrations of 6.25–400 ppm with kojic acid as a positive control. Statistical analysis using one-way ANOVA demonstrated significant differences among treatment groups (p 0.05). The antioxidant assay showed increasing inhibition activity with increasing extract concentration, with the highest inhibition observed at 800 ppm (89.92%). In the tyrosinase inhibition assay, the extract demonstrated concentration-dependent inhibitory activity, with the highest inhibition value observed at 400 ppm (58.00%), although the activity remained lower than kojic acid as the positive control (92.45%). The observed bioactivities are likely associated with the presence of flavonoids, tannins, and other phenolic compounds identified during phytochemical screening. In conclusion, Syzygium polyanthum extract exhibits promising antioxidant and tyrosinase inhibitory activities and has potential for further development as a natural antioxidant and anti-hyperpigmentation agent in cosmetic and pharmaceutical applications.