Combining in silico and in vitro approaches for understanding the mechanism of action of the galactomannan extracted from Cassia grandis seeds against colorectal cancer

Abstract

This study aimed to investigate the antitumor activity of galactomannan extracted from Cassia grandis seeds (GCg) against colorectal cancer cells using both experimental and computational approaches. Galactomannan was extracted from C. grandis seeds and prepared into solutions with varying concentrations. The cytotoxicity of these solutions was tested on HT-29 and HCT-116 colorectal cancer cell lines using the MTT assay. Additionally, computational evaluations, including molecular docking and molecular dynamics simulations, were performed to explore the potential binding interactions of GCg with cyclin-dependent kinase 2 (CDK2). The experimental results demonstrated that GCg significantly inhibited the proliferation of HT-29 cells, especially at concentrations of 5 mg/mL. On the other hand, no concentration inhibited >30 % of HCT-116 cells. Computational analysis revealed that GCg could bind to the ATP-binding site of CDK2, promoting the inactive DFG-out conformation, similar to the known inhibitor K03861. This interaction suggests a mechanism through which GCg may exert its anticancer effects. GCg exhibits significant cytotoxic activity against HT-29 colorectal adenocarcinoma cells, likely through the inhibition of CDK2; however, its efficacy against HCT-116 cells is limited, possibly due to structural differences in the molecular targets. To the best of the authors' knowledge, no studies have explored the applications of GCg in cancers, particularly colorectal ones. Further studies are needed to explore the antimetastatic effects and potential clinical applications of GCg in colorectal cancer treatment.

Keywords: CDK2 inhibition; Galactomannan; Molecular docking.