In vitro toxicity of low-level green laser irradiation effects on human breast cancer cell lines

Laser irradiation therapy on cancer cells is a promising alternative in providing a non-invasive treatment of breast cancer that has a possibility to inhibit cancerous cells selectively without damaging surrounding healthy tissues. This present study aimed to evaluate the effect of the low-level green laser of 532 nm wavelength with various laser power and irradiation time on MCF-7 cancer cell lines. In this work, the MCF-7 cells were seeded to a rate of fifty thousand cells/well in 96-well plate and incubated for 24 h. The cells were then irradiated with the green laser at different power from 0.002 to 0.1 W at 60 s, 540 s, and 900 s duration. The cell viability of the cells was measured by using Alamar Blue assay. From result, the laser irradiation on the cells was able to produce 25-40% inhibition of cell proliferation whereby the untreated cells exhibited a 93% cell viability. It was revealed that high power with longer exposure time increased cell bio-inhibition. Thus, this work using low-power green laser irradiation on cells demonstrated a significant effect on cells and was also demonstrated a promising non-invasive approach that can be used alone or in combination with several other therapies in cancer treatment.