Anticancer Activity of Endophytic Bacterial Extracts from Potentilla supina in HepG2 and HCT116 Cells

Endophytes in plant tissues produce diverse secondary metabolites, which hold promise for the development of new anticancer drugs. This study aimed to isolate endophytic bacteria from Potentilla supina and evaluate their anticancer activities. Seventy-two endophytic bacterial strains were isolated from P. supina, followed by fermentation and ethyl acetate extraction to prepare seventy-two strain extracts. The antiproliferative activity of these extracts against HepG2 and HCT116 cells was assessed using the MTT assay. Ultimately, high-activity strain J14 was screened out based on IC₅₀ values and selectivity indices (SI). The 48 h IC₅₀ values of its extract were 13.03 μg/mL for HepG2 cells and 21.82 μg/mL for HCT116 cells, with SI values of 4.196 and 2.506, respectively, indicating a favorable drug safety window. 16S rRNA gene sequencing indicated that strain J14 belongs to the genus Bacillus. Anti-SMASH analysis revealed that strain J14 contains eleven biosynthesis-related gene clusters (BGCs). Mechanistic studies showed that J14 extract significantly inhibited cancer cell malignant phenotypes: at 62.5 μg/mL, HCT116 and HepG2 colony formation decreased by 97.56% and 86.34% (P < 0.05), respectively; at 31.25 μg/mL, cell migration rates dropped to 38.62 and 52.20% of control (P < 0.01), respectively. It also induced reactive oxygen species (ROS) elevation. This is the first report exploring endophytic bacteria in P. supina that have anticancer potential, with the aim of providing more comprehensive theoretical support for research on endophytic bacteria with anticancer potential.