Naturally occurring carbazole alkaloid, Dentatin (DTN), is known to inhibit human cancer cell lines. However, it's inhibitory and immunomodulatory activities in colorectal carcinoma HCT-116 cells remain obscure. This study compares DTN's inhibitory effect against 5-FU in HCT-116 cells using in vitro anticancer assays including cell cytotoxicity, migration, colony formation, cell cycle and apoptosis, while assessing its immunomodulatory activity via Th1/Th2/Th17 inflammatory cytokines assay. DTN triggered the intrinsic and extrinsic apoptosis pathways by actuating caspases-8, -9 and -3 while inhibiting cell migration and colonies formation, and inducing cell cycle arrest at the G0/G1 phase. Accumulation of iROS with loss of MMP and DNA damage was observed with elevation of several Th1 cytokines, the TNF-alpha and IFN-gamma with lower pro-inflammatory IL-6 compared to 5-fluorouracil. In conclusion, DTN triggered ROS-mediated apoptosis with release of inflammatory cytokines, potentially evoking anticancer immunity in CRC. Further validation of DTN's mechanism in vivo is warranted.