Effect of UV irradiation on aflatoxin reduction: a cytotoxicity evaluation study using human hepatoma cell line.

In this proof-of-concept study, the efficacy of a medium-pressure UV (MPUV) lamp source to reduce the concentrations of aflatoxin B, aflatoxin B, and aflatoxin G (AFB AFB, and AFG) in pure water is investigated. Irradiation experiments were conducted using a collimated beam system operating between 200 to 360 nm. The optical absorbance of the solution and the irradiance of the lamp are considered in calculating the average fluence rate. Based on these factors, the UV dose was quantified as a product of average fluence rate and treatment time. Known concentrations of aflatoxins were spiked in water and irradiated at UV doses ranging from 0, 1.22, 2.44, 3.66, and 4.88 J cm. The concentration of aflatoxins was determined by HPLC with fluorescence detection. LC-MS/MS product ion scans were used to identify and semi-quantify degraded products of AFB, AFB, and AFG. It was observed that UV irradiation significantly reduced aflatoxins in pure water (p < 0.05). Irradiation doses of 4.88 J cm reduced concentrations 67.22% for AFG, 29.77% for AFB, and 98.25% for AFB (p < 0.05). Using this technique, an overall reduction of total aflatoxin content of ≈95% (p < 0.05) was achieved. We hypothesize that the formation of ˙OH radicals initiated by UV light may have caused photolysis of AFB, AFB, and AFG molecules. In cell culture studies, our results demonstrated that the increase of UV dosage decreased the aflatoxin-induced cytotoxicity in HepG cells. Therefore, our research finding suggests that UV irradiation can be used as an effective technique for the reduction of aflatoxins.