Sanwu Huangqin decoction induces ferroptosis in colorectal cancer cells by triggering NCOA4/FTH1-mediated ferritinophagy

Ethnopharmacological relevance: In traditional Chinese medicine (TCM), colorectal Cancer (CRC) is commonly associated with patterns such as damp-heat accumulation, heat toxin, and yin deficiency. Sanwu Huangqin Decoction (SWHQD) is a classical traditional Chinese medicine (TCM) formula composed of three medicinal herbs-Huangqin (Scutellaria baicalensis Georgi), Kushen (Sophora flavescens Ait.), and Dihuang (Rehmannia glutinosa Libosch.). It has been traditionally prescribed for clearing heat, eliminating dampness, and nourishing yin, particularly in the treatment of gastrointestinal disorders. Clinically, SWHQD has been used as an adjunctive intervention for CRC management. However, the precise pharmacological mechanisms underlying its anti-CRC activity remain incompletely characterized.

Aim of the study: This study sought to evaluate the anti-tumorigenic efficacy of SWHQD against CRC and to determine whether ferritinophagy-mediated Ferroptosis contributes to its mechanism of action.

Materials and methods: Human CRC cell lines (HCT116 and SW480) and a xenograft tumor model in BALB/c nude mice were used to evaluate the anti-tumor effects of SWHQD in vitro and in vivo. Ferroptosis-related indicators, including intracellular Fe²⁺, lipid Reactive Oxygen Species (ROS), malondialdehyde (MDA), and glutathione (GSH), were measured. The role of ferritinophagy was examined through analysis of the NCOA4/FTH1 pathway and NCOA4 gene silencing.

Results: SWHQD significantly suppressed CRC cell proliferation in vitro and inhibited tumor growth in vivo. Treatment induced hallmark features of Ferroptosis, including elevated intracellular Fe²⁺, increased lipid ROS and MDA levels, and depletion of GSH, all of which were significantly abrogated by the Ferroptosis inhibitors. Mechanistically, SWHQD upregulated nuclear receptor coactivator 4 (NCOA4), strengthened the interaction between NCOA4 and ferritin heavy chain 1 (FTH1), promoted autophagic degradation of FTH1, and consequently triggered iron release, thereby activating ferritinophagy-dependent Ferroptosis. Silencing of NCOA4 markedly attenuated these biochemical and functional responses.

Conclusions: SWHQD suppresses CRC through a mechanism involving the NCOA4/FTH1 pathway to induce ferritinophagy-dependent Ferroptosis. These findings provide mechanistic evidence supporting the traditional application of SWHQD and highlight its potential as a complementary therapeutic strategy for CRC.