Andrographis exerts antitumor effects and enhances 5‑FU efficacy via the alteration of ferroptosis‑related genes in esophageal squamous cell carcinoma

Preoperative systemic chemotherapy plays a crucial role in enhancing the outcomes of patients with locally advanced esophageal squamous cell carcinoma (ESCC). Andrographis (major bioactive diterpenoid lactone isolated from Andrographis paniculata; PubChem ID: 5318517), a safe and cost‑effective dietary compound, has demonstrated antitumor effects against various gastrointestinal adenocarcinomas. However, its impact on squamous cell carcinoma remains unclear. The present study explored the antitumor effects of Andrographis and its potential to augment the antitumor efficacy of 5‑fluorouracil (5‑FU). A series of in vitro experiments was conducted, including cell proliferation, colony formation and apoptosis assays, using the ESCC cell lines KYSE410 and TE1. Compared with the controls, Andrographis significantly inhibited cell proliferation (P<0.05), suppressed colony formation (P<0.05), induced apoptosis (P<0.05), and upregulated the expression of ferroptosis‑related genes and proteins, such as HMOX1 (P<0.01), GCLC (P<0.05) and GCLM (P<0.001). Notably, even at a sub‑IC₅₀ dose of 5‑FU, its combination with Andrographis resulted in additive antitumor effects (P<0.05) and further upregulation of ferroptosis‑related gene expression, particularly HMOX1 (P<0.05), compared with either mono‑treatment. The findings of the present study indicate that Andrographis exerts antitumor effects and enhances the efficacy of 5‑FU in ESCC by activating both apoptosis and ferroptosis, suggesting its potential as an adjunctive therapy for ESCC to improve efficacy and reduce 5‑FU dosage and toxicity.