Shiitake mushroom (SM; Lentinus edodes) are cultivated and consumed in many Asian countries including Vietnam, China, Japan, Korea, and Thailand. In Asia, SM are mainly dried and used as flavoring. The aim of this study was to compare the effects of SM created with different drying processes, such as oven-dried and sun-dried, on the antioxidative and antigenotoxic effects. Raw and dried SM were extracted with acetone, ethanol, methanol, and hot water. The antioxidant effects of SM were evaluated by determining total phenolic content, DPPH radical scavenging activity (RSA), an ORAC assay, and a cellular antioxidant capacity (CAC) assay. The inhibitory effect of SM on oxidative stress-induced DNA damage in human leukocytes was evaluated by a Comet assay. The total phenolic content of raw SM extracted with methanol and of that extracted with water were significantly higher than the dried SM. Among the water extracts, the IC50 for DPPH RSA of raw and sun-dried SM were significantly higher than that of oven-dried SM. Sun-dried SM showed the most potent ORAC value at 50 g/mL. The CAC against AAPH -induced oxidative stress in HepG2 cells, and H2O2 induced DNA damage were effectively protected against by all SM extracts. These results suggest that unprocessed SM are the best antioxidants, and that the sun-dried method would be the best option to use in terms of antioxidant activity and the antigenotoxic effect.

No abstract