[Active fractions of Camellia nitidissima inhibit non-small cell lung cancer via suppressing epidermal growth factor receptor].

The present study explored the effects and its underlying mechanisms of four active fractions of Camellia nitidissima(leaf polyphenols, leaf saponins, flower polyphenols, and flower saponins in C. nitidissima) in inhibiting the proliferation and migration of non-small cell lung cancer(NSCLC) by suppressing the epidermal growth factor receptor(EGFR). MTT assay was used to detect the effect of four active fractions on the proliferation of NCI-H1975 and HCC827 cells. Wound healing assay and Transwell assay were adopted to evaluate the effect of four active fractions on the migration of NSCLC. The effect of four active fractions on the enzyme activity of EGFR was detected. Molecular docking was carried out to explore the direct action capacity and action sites between representative components of the four active fractions and EGPR. Western blot assay was employed to investigate the effect of four active fractions on the protein expression in EGFR downstream signaling pathways. The results of the MTT assay indicated that the cell viability of NCI-H1975 and HCC827 cells was significantly inhibited by four active fractions at 50, 100, 150, and 200 μg·mL~(-1) in a dose-dependent manner. Wound healing assay and Transwell assay revealed that the migration of NCI-H1975 and HCC827 cells was significantly suppressed by four active fractions. In addition, the results of the protein activity assay showed that the enzyme activity of EGFR was significantly inhibited by four active fractions. The molecular docking results confirmed that various components in four active fractions possessed strong binding activity to EGFR enzymes. Western blot assay revealed that four active fractions down-regulated the protein expression of EGFR and its downstream signaling pathways. It is concluded that the four active fractions of C. nitidissima can inhibit NSCLC. The mechanism may be related to EGFR and its downstream signaling pathways. This study provides a new scientific basis for the clinical treatment of NSCLC with active fractions of C. nitidissima, which is of reference significance for further research on the anti-tumor mechanism of C. nitidissima.