Abstract
Chaga mushroom (Inonotus obliquus) exhibits cytotoxic effects against breast cancer cells. Mycosynthesized nanoparticles, owing to their biodegradability, biocompatibility, and low toxicity, present a promising therapeutic approach. This study explored the cytotoxic potential of gold nanoparticles synthesized using Chaga mushroom extract (AuCh-NPs) combined with Light Emitting Diode (LED) irradiation (530 nm) on human breast cancer (MCF-7) cells, aiming to develop a safe and effective sensitizer for photothermal therapy. The AuCh-NPs were characterized using UV-visible spectroscopy, FTIR, TEM, particle size analysis, and zeta potential measurements. Cytotoxicity was evaluated via MTT assay under LED irradiation with total light exposure 325.8 and 488.7 J cm(-2), alongside mechanistic studies involving wound healing, autophagy, cell cycle arrest, annexin V analysis, real-time PCR, and comet assays.TEM revealed spherical AuCh-NPs with sizes ranging from 15.4 to 28.9 nm. The MTT assay demonstrated enhanced cytotoxicity under LED irradiation, with AuCh-NPs exhibiting a lower IC50 (5.56 µM) than citrate-capped gold nanoparticles (AuCit-NPs, 7 µM). Cell cycle analysis revealed significant arrest in G0/G1 (91.68%) and S (7.55%) phases, while annexin V analysis confirmed apoptosis induction. Real-time PCR showed upregulation of the pro-apoptotic genes BAX, and the comet assay indicated increased double-strand DNA damage in MCF-7 cells treated with AuCh-NPs compared to AuCit-NPs. These findings highlight the superior selective cytotoxicity of AuCh-NPs against MCF7 cells, positioning them as a promising targeted agent for photothermal therapy in breast cancer treatment.