Synthesis of gold nanoparticles using Ginkgo biloba leaf extract and its in vitro anticancer effects on nasopharyngeal carcinoma cells

Green synthesis of gold nanoparticles (AuNPs) using Ginkgo biloba leaf aqueous extract was optimized by response surface methodology to yield monodispersed, crystalline nanoparticles of 18 ± 4 nm diameter. Fourier transform infrared spectroscopy confirmed capping by flavonoids, terpenoids and polyphenols providing stability for over 6 months. The biosynthesized AuNPs exhibited promising in vitro dose and time-dependent antiproliferative effects against human nasopharyngeal carcinoma CNE1 cells with IC50 reducing from 65.7 to 39.2 μg/mL over 24–72 hrs. Distinct cytoplasmic damage was observed under microscope. Treatment with 50 μg/mL AuNPs for 48 hrs dramatically upregulated pro-apoptotic Bax, Caspase-3 and p53 by 8.7, 6.5 and 4.3 fold respectively while downregulating anti-apoptotic Bcl-2 by 11.2 fold, indicating apoptosis induction via mitochondrial intrinsic pathway. The green fabricated G. biloba AuNPs displayed preferential toxicity towards carcinoma cells compared to normal fibroblasts, indicating potential for targeted nasopharyngeal cancer therapy.