JI-CS004, a chloroform fraction of SH003, induces reactive oxygen species-dependent intrinsic apoptosis via endoplasmic reticulum stress-associated mitochondrial dysfunction in human colorectal cancer cells.

UNLABELLED: Conventional therapies for colorectal cancer (CRC) are often limited by toxicity and therapeutic resistance. Alternative therapeutic strategies are therefore needed. Natural product-derived compounds have been explored as potential anticancer agents. The molecular mechanisms underlying the anticancer effects of JI-CS004, a chloroform fraction derived from the herbal formulation SH003, against CRC remain unclear.

METHODS: The anticancer effects of JI-CS004 were evaluated in CRC cell lines by assessing reactive oxygen species (ROS) generation, ER stress signaling, mitochondrial dysfunction, and intrinsic apoptosis. ROS dependency was examined using N-acetylcysteine (NAC). Antitumor activity was evaluated in an HCT116 xenograft model.

RESULTS: JI-CS004 substantially reduced CRC cell viability and induced intracellular ROS accumulation. ROS scavenging by NAC markedly attenuated JI-CS004-induced cytotoxicity, ER stress signaling, mitochondrial dysfunction, and intrinsic apoptosis, supporting an important contribution of ROS to these cellular responses. JI-CS004 activated ER stress-related signaling through the PERK/eIF2α/ATF4 and IRE1α/JNK pathways, increased CHOP expression, reduced mitochondrial membrane potential and OXPHOS complex expression, and induced intrinsic apoptosis accompanied by cytochrome c release and caspase-9/3 activation. In vivo, JI-CS004 substantially suppressed tumor growth and increased the expression of CHOP and cleaved caspase-3.

CONCLUSIONS: JI-CS004 induces ROS-dependent intrinsic apoptosis associated with ER stress and mitochondrial dysfunction, supporting further investigation of its anticancer potential in CRC.