Figure 2: Effects of antioxidants on keratinocyte viability. Cells were serum-starved for 24 hrs and then treated with antioxidant plant extracts at 0.1–100 μg/mL for 24 hrs in serum-free media. Cell viabilities were determined using MTT assays. Each determination was made in triplicate, and the data shown are the means ± SD. G. l: G. lucidum; R. s: R. sachalinensis.