Tyrosinase Inhibitory Activity of n-Hexane, Ethyl Acetate and Methanol Extracts of Padina sp

Abstract

Melanin is a color pigment in the skin, if produced in excess will cause browning of the skin. The formation of melanin (melanogenesis) is assisted by tyrosinase through two reactions, namely monophenolase and diphenolase. Melanogenesis can be reduced through the tyrosinase enzyme inhibition mechanism. Seaweed can be used as a tyrosinase inhibitor (brightening agent), such as Padina sp containing secondary metabolites such as alkaloids, flavonoids, terpenoids, phenolics, and saponins. This study aimed to determine the tyrosinase inhibitory activity of Padina sp. The extraction method used was graded maceration with n-hexane (n-Hx), ethyl acetate (Et-OAc), and methanol (Me-OH) solvents, then carried out phytochemical screening, antioxidant test using the DPPH method, and tyrosinase inhibitory test by measuring the enzymatic reaction using L-tyrosine (monophenolase) and L-DOPA (diphenolase). Phytochemical analysis of extracts by GC-MS and in silico analysis by molecular docking were also carried out. The results showed that the total yield of the three extracts was 5.50%. The three extracts had moderate category of antioxidants. The IC50 values monophenolase of n-Hx, Et-OAc, Me-OH extracts, and Kojic acid were 937.68; 132, 92; 268.68; and 20.99μg/mL, respectively. The IC50 values diphenolase of n-Hx, Et-OAc, Me-OH extracts, and Kojic acid were 989.74; 178.33; 356, 87; and 31.76 μg/mL, respectively. The phytochemical of Et-OAc extract based on GC-MS data showed a variety of compounds that have been shown to have pharmacological effects. This data is supported by the results of molecular docking analysis, where compound Spiro(tetrahydrofuryl)2.1'(decalin), 5',5',8'a-trimethyl (1) is able to show a relatively low binding energy, namely -6.86 kcal/mol. The binding energy is even lower than the standard compound (Kojic acid) interaction which only has binding energy of -3.73 kcal/mol. Based on the study carried out, extract from Padina sp has the potential to be developed as a a skin brightening agent.