Introduction:
In the present study, gold nanoparticles were prepared and synthesized in aqueous medium using Verbascum thapsus leaf extract. We assessed the anti-human lung cancer potential of these nanoparticles against well-differentiated bronchogenic adenocarcinoma, moderately differentiated adenocarcinoma of the lung, and poorly differentiated adenocarcinoma of the lung cell lines.

Material and methods:
AuNPs were characterized and analyzed by common nanotechnology techniques including Fourier transform infrared (FT-IR) and ultraviolet-visible (UV-Vis) spectroscopy, field emission-scanning electron microscopy, and transmission electron microscopy. In the FT-IR test, the presence of many antioxidant compounds with related bonds caused excellent conditions for reduction of gold in the gold nanoparticles. In UV-Vis, the clear peak at the wavelength of 548 nm indicated the formation of gold nanoparticles. For determining anti-human lung cancer properties of HAuCl4, V. thapsus, and AuNPs, MTT assay was used on normal (HUVECs), well-differentiated bronchogenic adenocarcinoma (HLC-1), moderately differentiated adenocarcinoma of the lung (LC-2/ad), and poorly differentiated adenocarcinoma of the lung (PC-14) cell lines.

Results:
AuNPs had excellent anti-human lung cancer effects dose-dependently against HLC-1, LC-2/ad, and PC-14 cell lines. The best result of anti-human lung cancer activities of AuNPs against the above cell lines was observed in the case of the PC-14 cell line.

Conclusions:
The synthesized AuNPs showed significant anti-human lung cancer properties against well-differentiated bronchogenic adenocarcinoma, moderately differentiated adenocarcinoma of the lung, and poorly differentiated adenocarcinoma of the lung cell lines in a dose-dependent manner.