Research Paper Advance Articles

Figure 6. Identification of honokiol as a core ingredient showing antioxidant effects. (A) Senescent fibroblasts were treated with DMSO (0.01%) or honokiol (0.1, 1, and 10 μM) for 12 days. Use of DHR123 for flow cytometric analysis of mitochondrial ROS levels. The extract of M. officinalis extract (0.625 μg/ml) served as a positive control. Honokiol at 1 and 10 μM was more effective in reducing ROS levels than M. officinalis extract. n.s. (not significant), **P < 0.01, ***P < 0.001, Student’s t–test. Mean ± S.D., N = 3. (B) Senescent fibroblasts were treated with DMSO (0.01%) or magnolol (0.1, 1, and 10 μM) for 12 days. Use of DHR123 for flow cytometric analysis of mitochondrial ROS levels. The extract of M. officinalis extract (0.625 μg/ml) served as a positive control. Magnolol at 1 and 10 μM was not more effective in reducing ROS levels than M. officinalis extract. n.s. (not significant), ***P < 0.001, **P < 0.01, Student’s t–test. Mean ± S.D., N = 3. (C) Senescent fibroblasts were treated with DMSO (0.01%) or honokiol (1 μM). Measurement of cell viability after 0, 4, 8, and 12 days of treatment. n.s. (not significant), two–way ANOVA followed by Bonferroni’s post–hoc test. Mean ± S.D., N = 3. (D) Cellular proliferation was evaluated at DMSO (0.01%) or honokiol (1 μM) on day 12 after treatment in senescent fibroblasts. ***P < 0.001, Student’s t–test. Mean ± S.D., N = 3. (E) Senescent fibroblasts were treated with DMSO (0.01%) or honokiol (1 μM) for 12 days. Use of MitoSOX for flow cytometric analysis of mitochondrial ROS levels. **P < 0.01, Student's t–test. Mean ± S.D., N = 3.