Uji Aktivitas Penghambatan Enzim Tirosinase secara In Vitro dari Ekstrak Etanol Daun Sijukkot (Lactuca indica L.)

Abstract

Background: The rising of hyperpigmentation prevalence has become a worldwide problem and a natural based brightening agent is needed. Sijukkot (Lactuca indica L.) is native plants to North Sumatera which are utilized by local community for medicinal purposes, yet there is still very little research for its activities, particularly as a brightening agent through tyrosinase enzyme inhibition pathway. Objective: The aim of this research was to assess the concentrations of total phenolic content, total flavonoid content, antioxidant activity, and tyrosinase enzyme inhibition activity of ethanol extract of sijukkot leaves (L. indica). Method: Assessment of total phenolic content was carried out using the Folin-Ciocalteu reagent, whereas total flavonoid content was determined using AlCl3 reagent. Antioxidant activity assay was carried out using the DPPH. The tyrosinase enzyme inhibitory activity was tested. Results: The result of the study on ethanol extract of L. indica showed that the total phenolic content (TPC) was 145.35 ± 0.08 mg GAE/g extract and the total flavonoid content (TFC) was 21.89 ± 0.95 mg QE/g extract. Antioxidant activity by DPPH method of ethanol extract L. indica was obtained with IC50 value of 50.19 ± 0.53 μg/mL and the tyrosinase enzyme inhibitory activity was obtained with IC50 value of 2,871.03 μg/mL. Conclusion: It can be concluded that the ethanol extract of sijukkot leaves (L. indica) contains phenolic and flavonoid compounds, and strong antioxidant activity, however has very weak tyrosinase enzyme inhibition activity.