Effect of low-level laser irradiation on cytotoxicity of benzene in human normal fibroblast cells.

Abstract

Benzene is volatile organic hydrocarbon which is widely used in a wide range of industries. Studies have shown that exposure to benzene consequences serious health risks for human. Understanding the effect and risks of environmental hazard materials in the laser therapy of skin is interesting which can show useful or harmful role of these effects in therapies. In this study, the effect of low-level laser therapy was investigated on benzene-induced cytotoxicity on human skin fibroblast cells (HU02). Human skin fibroblast cells (HU02) were exposed to various concentrations of benzene (0-100μg/mL) and incubated for 2h. Then the effect of low-level laser therapy (LLLT) at 660-nm wavelength with 3J/cm2 energy for 90s was investigated on the viability of the cells exposed to benzene using MTT assay and inverted light microscope. The effect of low-level laser therapy on the viability of the cells was positive at concentrations 0-15μg/mL but negative at higher concentrations than 15μg/mL. Low-level laser therapy in low concentrations of benzene decreases the cytotoxicity caused by benzene and maintains cell viability. At high concentrations and in the presence of low-level laser therapy, the cell viability decreased compared to dark experiment. The morphology study of the cells using inverted light microscopy has confirmed the MTT results.