Identification of HMOX-1-Targeting Natural Compounds in Camellia nitidissima Chi for NSCLC Therapy: Integrating Bioassay and In Silico Screening Approaches.

Background/

Objectives

Camellia nitidissima Chi (C. nitidissima), a traditional Chinese "food and medicine homology" plant, has demonstrated potential anti-tumor properties. However, its mechanisms of anti-lung cancer activity via ferroptosis remain unclear. This study aimed to construct an integrated research system of "natural product extraction-purification, bioactivity evaluation, and computational drug screening" to explore the bioactive compounds in C. nitidissima leaves targeting HMOX-1-mediated ferroptosis and their anti-lung cancer mechanisms.

Methods

Active fractions were prepared using ethanol extraction combined with polyamide column chromatography. The anti-lung cancer activity was evaluated using the NCI-H1975 cell model. Ferroptosis was verified via transmission electron microscopy (TEM), biochemical indicators, a PCR Array, and immunofluorescence. The bioactive compounds were identified using UPLC-Q Exactive MS, and their binding affinity to HMOX-1 was evaluated via molecular docking and dynamics simulations, followed by cellular validation.

Results

The 95% F1 fraction from the extracts of C. nitidissima leaves exhibited the strongest anti-lung cancer activity, which could be significantly reversed by Ferrostatin-1. Furthermore, it induced typical ferroptosis-related structural damage in mitochondria, including shrinkage and a reduction in size, increased membrane density, and a reduction or even the disappearance of cristae structures. At the molecular level, this fraction significantly increased the levels of oxidative stress markers (ROS↑, MDA↑, Fe2+↑, and GSH↓) and upregulated the expression of key ferroptosis-related genes, including HMOX-1, CHAC1, and NOX1. Using UPLC-Q Exactive MS combined with computational simulation methods, four bioactive compounds with high affinity for HMOX1 were successfully identified, including isochlorogenic acid A (-8.4 kcal/mol), isochlorogenic acid C (-8.4 kcal/mol), apigenin (-7.8 kcal/mol), and chrysin (-7.3 kcal/mol). Cellular experiments validated that these compounds exhibited dose-dependent anti-proliferative effects.

Conclusions

The leaves of C. nitidissima induce anti-lung cancer effects via HMOX-1-mediated ferroptosis. Isochlorogenic acid A/C, apigenin, and chrysin were identified as key bioactive components. These findings lay the foundation for the development of natural ferroptosis-targeted drugs.