Abstract
Cancer is one of the leading causes of death in the world. Efforts to find and develop cancer drugs from natural products continue with the exploration of trisindoline, a substance that is isolated from marine sponges Hyrtios altum. Trisindoline is an indole trimer alkaloid compound that has been successfully synthesized into trisindoline 1, 3 and 4. Trisindoline is cytotoxic in cell lines and in this study, trisindoline was able to induce apoptosis in the in silico and in vitro tests that were carried out. The in silico test was carried out through molecular docking using the Autodock Vina method and the Molecular Dynamics (MD) Simulation QM / MM AMBER. The target proteins used were protein p53 and caspase -9 which played a role in the apoptotic pathway and cyclin D1 which played a role in cell proliferation. Meanwhile, cytotoxicity analysis was carried out using the MTT method (3- (4,5-dimethyltiazol -2-yl) -2,5 -dipenyl tetrazolium bromide). Nevertheless, the ability of trisindoline to induce phagocytosis is still unrevealed. The phagocytosis assay was carried out by assessing the macrophage capacity and phagocytic index using the latex-beads model. The in silico results showed that the binding affinity values between the target protein Cdk-2 and the trisindoline 1, trisindoline 3 and trisindoline 4 ligands were -7.3 kcal / mol, -7.7 kcal / mol and -6.6 kcal / mol respectively. The binding affinity values between the target protein p53 and the trisindoline 1, trisindoline 3 and trisindoline 4 ligands were -7.5 kcal / mol, -7.4 kcal / mol and -7.5 kcal / mol respectively. The binding affinity values between the target protein caspase-9 and the trisindoline 1, trisindoline 3 and trisindoline 4 ligands were -7.5 kcal / mol, -7.1 kcal / mol and -7.2 kcal / mol respectively. The results of RMSD (Root Mean Square Deviation), RMSF (Root Mean Square Fluctuation), and hydrogen bonds in the MD (Molecular Dynamics) Simulation showed that Cdk-2 formed a protein complex with trisindoline 3, protein p53 with trisindoline 1 and caspase-9 with trisindoline 1. The cytotoxicity assay was carried out in the MCF-7 cell line and the IC50 value obtained for trisindoline 1 was 2.059 μM, for trisindoline 3 was 3.9759 μM, for trisindoline 4 was 15.46 μM and for doxorubicin was 9.88 μM. Furthermore, the phagocytosis test was carried out using trisindoline 1, 3 and 4. Our results showed that 6.25 µg mL(-1) of trisindoline 1 and trisindoline 3 were able to induce the phagocytosis capacity of macrophage cells of 38.34; whereas trisindoline 4 at a concentration of 50 µg mL(-1) induces a phagocytosis capacity of 32.89. Trisindoline 1, 3 and 4 showed potentials of immunostimulants at low concentrations but showed potentials of immunosuppressants at high concentrations. The overall results demonstrated that trisindoline 1 and 3 are potential anti-cancer candidates capable of activating the apoptotic pathway.