Effect of AGI $({alpha}-Glucosidase;Inhibitor)-1120$, pine (Pinus densiflora) bark extract and Chaga mushroom (Inonotus obliquus) - and Chaga mushroom mycelium extracts on cellular $NF-{kappa}B$ activation in malignant human keratinocytes (SCC-13) were evaluated to elucidate the possible correlation of $NF-{kappa}B$ with antioxidant activity. The antioxidant activities of these natural products were examined in three different evaluation methods, i.e., lipid peroxidation value (POV) evaluation test, and 1,1diphenyl-2-picrylhydrazyl radical (DPPH) and nitric oxide (NO) scavenging test. In a cell-based $NF-{kappa}B$ monitoring assay systern, all samples revealed the downregulatory profiles on the cellular $NF-{kappa}B$ activity. AGI -1120 (1, 2 mg) and Chaga mushroom extract (0.05, 0.1 mg) downregulated the $NF-{kappa}B$ activity in a dose-dependent manner. Chaga mushroom mycelium extract (5 mg) significantly inhibited the $NF-{kappa}B$ activity (p<0.05). Although AGI-1120 and Chaga mushroom mycelium extract exhibited no antioxidant activities evaluated in pay, Chaga mushroom extract showed antioxidant in a dose-dependent manner at concentrations of $0.05{sim}1$ mg. While AGI-1120 and Chaga mushroom extract possessed a relatively potential DPPH radical scavenging activity, the NO scavenging activity of Chaga mushroom extract $(SC_{50}:47;{mu}g)$ was higher than the known antioxidant, vitamin C $(SC_{50}:77;{mu}g)$. These results suggest that AGI-1120 and Chaga mushroom- and Chaga mushroom mycelium extracts may serve as an useful radical scavenging antioxidant agents with $NF-{kappa}B$ inhibitory effect in human skin.