Aktivitas Penghambatan dan Studi Kinetika Inhibisi a-Glukosidase Ekstrak Etanol Kulit Batang Surian (Toona sinensis)

Abstract

Surian (Toona sinensis) merupakan tanaman yang berpotensi dimanfaatkan sebagai obat antidiabetes. Penelitian terkait kulit batang surian sebagai inhibitor aglukosidase masih terbatas. Penelitian ini bertujuan menganalisis aktivitas inhibisi a-glukosidase ekstrak etanol kulit batang surian pada variasi konsentrasi (30, 70, dan 96%), studi kinetika inhibisi, dan analisis aktivitas inhibisi a-glukosidase dengan pendekatan studi kinetika. Metode penelitian meliputi analisis kadar air, ekstraksi, uji aktivitas inhibisi a-glukosidase, studi kinetika a-glukosidase, dan analisis data. Pelarut etanol 70% menunjukkan efisien dalam mengekstraksi simplisia kulit batang surian yang ditunjukkan oleh nilai rendemen tertinggi (12,71% ± 1,01). Ekstrak etanol 96% menghasilkan aktivitas inhibisi a-glukosidase terbaik (IC50 = 175,25 ± 2,11 µg/mL) melalui mekanisme inhibisi campuran (mixed) berupa kombinasi inhibisi non-kompetitif-kompetitif (KIC < KIU). Analisis aktivitas inhibisi a-glukosidase secara matematis berdasarkan persamaan Prusoff-Cheng menghasilkan nilai IC50 yang tidak jauh berbeda dengan nilai IC50 secara eksperimental (IC50 = 174,99 µg/mL). Persamaan ini dapat menjelaskan pengaruh konsentrasi substrat terhadap nilai IC50 bergantung pada tipe inhibisi, kecuali tipe inhibisi non-kompetitif.

Surian (Toona sinensis) is one of the plants with potential as an antidiabetic agent. Research on the potential of surian stem bark as a-glucosidase inhibitors is still limited. This study aims to analyze the a-glucosidase inhibitory activity of ethanol extracts of surian stem bark at various concentrations (30, 70, and 96%), inhibition kinetics study, and analyze the a-glucosidase inhibitory activity using a kinetic study approach. The research methods included moisture content analysis, extraction, a-glucosidase inhibition assay, kinetic studies of a-glucosidase, and data analysis. The 70% ethanol solvent was efficient for extracting as indicated by the highest yield value (12,71% ± 1,01). The 96% ethanol extract exhibited the best inhibitory activity a-glucosidase (IC50 = 175,25 ± 2,11 µg/mL) through a mixed inhibition mechanism, specifically a combination of non-competitive-competitive inhibition (KIC < KIU). The mathematical analysis of a-glucosidase inhibitory activity based on the Prusoff-Cheng equation yielded an IC50 value (174,99 µg/mL) that closely matched the experimentally obtained IC50. This equation can explain the effect of substrate concentration on the IC50 value depending on the type of inhibition, except in the case non-competitive inhibition.