Pengaruh Variasi Pelarut Ekstrak Kulit Batang Surian (Toona sinensis) Terhadap Kandungan Total Tanin dan Aktivitas Tirosinase

Abstract

Paparan radiasi sinar UV berlebih memicu timbulnya hiperpigmentasi. Tirosinase sebagai enzim kunci yang mengatur biosintesis melanin dapat dihambat oleh inhibitor tirosinase. Kulit batang surian mengandung flavonoid, triterpenoid, dan tanin yang memiliki potensi sebagai inhibitor tirosinase. Penelitian ini bertujuan mengidentifikasi pengaruh variasi pelarut ekstraksi (metanol, etanol 70%, dan etil asetat) kulit batang surian terhadap kandungan total ranin dan aktivitas tirosinase. Jenis tanin diidentifikasi melalui uji kualitatif dan dilanjutkan penentuan kadar total dengan metode vanillin-HCl. L-tirosin berperan sebagai substrat untuk mengukur aktivitas inhibisi pada jalur monofenolase. Hasil penelitian menunjukkan aktivitas inhibisi terhadap tirosinase tertinggi diperoleh dari ekstrak etil sebesar 80,96%, dan terendah dari ekstrak etanol 70% sebesar 68,33%. Ekstrak etil asetat menghasilkan nilai IC50 terbaik (369,92 mg/L) dengan total tanin tertinggi sebesar 299,11 ±0,17 mg CE/g ekstrak untuk jenis tanin terkondensasi. Hubungan total tanin dengan % inhibisi tirosinase diperoleh pada derajat korelasi positif kuat. Simpulan penelitian ini menunjukkan total tanin terkondensasi dan aktivitas penghambatan kulit batang surian terhadap tirosinase dipengaruhi oleh jenis pelarut dan memiliki potensi sebagai agen inhibitor tirosinase dalam industri kosmetik.

Excessive exposure to UV radiation triggers hyperpigmentation. Tyrosinase, a key enzyme regulating melanin biosynthesis, can be inhibited by tyrosinase inhibitors. The bark of the Surian tree (T. sinensis) contains flavonoids, triterpenoids, and tannins that have potential as tyrosinase inhibitors. This study aimed to identify the effect of different extraction solvents (methanol, 70% ethanol, and ethyl acetate) on the total tannin content and tyrosinase activity of surian bark extracts. The types of tannins were identified through qualitative tests and followed by total content determination using the vanillin-HCl method. L-tyrosine was used as a substrate to measure inhibition activity in the monophenolase pathway. The results showed that the highest tyrosinase inhibition activity was obtained from the ethyl extract at 80,96%, while the lowest was from the 70% ethanol extract at 68,33%. The ethyl acetate extract produced the best IC50 value of 369,92 mg/L, with the highest total tannin content of 299,11±0.17 mg CE/g for condensed tannins. Additionally, a strong positive correlation was found between total tannins and tyrosinase inhibition percentage. In conclusion, this study indicated that the total condensed tannin and tyrosinase inhibition activity of Surian bark are influenced by the type of solvent used, demonstrating its potential as a tyrosinase inhibitor agent in the cosmetic industry.