Potential of Kesambi Active Compound (Schleichera oleosa) as Antagonist G-Protein Estrogen Receptor 1 (GPER1) by In Silico

Tamoxifen is a treatment for breast cancer patients which can cause side effects of endometrial because it acts as GPER1 agonist. Active compounds from Schleichera oleosa are known to have anticancer potential, such schleicheol and schleicherastatin, especially their ability prevent cell proliferation. This research conducted an in silico study determine the potential active compound S. Oleosa inhibitor. In studies include molecular docking dynamics. The data obtained binding affinity values, energy, RMSD, RMSF, conformational changes. candidates with lowest were selected, namely Schleicheol 1 (SCL1), Lupeol (LU), acetate (LA), Betulinic acid (BA), Schleicherastatin 3 (SCR3) order score -8.6, - 8.5, -8.4, -8.4 kcal.mol-1. When complexed GPER1-Estradiol GPER1-Tamoxifen, was LU (-8.6 -8.7 kcal.mol-1). binds same amino Estradiol Tamoxifen, Leu:271. Based on dynamics, RMSD All (receptor complex) ranged 3,723 5,098 Å, above normal limit Å. However, shows stability starting 1.5 ns so that resulting be used. RMSF value showed higher fluctuations than at site including SCL1-T, LU-T, LA-T, BA-T, interfere function receptor. LU, LA, BA, SCL1-T LA-T produce structural changes G15 antagonists. compound, lupeol, has affinity, predicted inhibit proposed further testing. Keywords: Endometrial Cancer, GPER1, oleosa, Tamoxifen.