Fig. 2From: Andrographolide induces Nrf2 and heme oxygenase 1 in astrocytes by activating p38 MAPK and ERKAndrographolide increases stability of Nrf2 protein by altering ubiquitination efficiency. Primary astrocytes were treated with andrographolide (50 μM) for the indicated time intervals and measured for immunoreactivities of a pSer40 Nrf2/total Nrf2 as well as b Keap1 immunoreactivity normalized to β-actin (with representative immunoblots), and bar graphs showing mean ± S.E.M. fold changes in optical density (OD) with vehicle-only (“0 h”) group set as 1. ***p < 0.001; significantly different from vehicle-only group (one-way ANOVA with Dunnett’s post hoc tests). c Rat primary astrocytes were treated with cycloheximide (CHX, 10 μg/mL) with or without andrographolide (50 μM) co-incubation for the indicated time intervals and then measured for total Nrf2 immunoreactivity (with representative immunoblots). The graph represents mean ± S.E.M. Nrf2 immunoreactivities in vehicle-only (filled circles) and andrographolide co-treated (open circles) groups expressed as % of untreated (“0 h” CHX) group. *p < 0.05; significantly different from vehicle-only group (Student’s t tests). d Rat primary astrocytes were incubated with or without 50 μM of andrographolide for 1 h and processed for immunoprecipitation (see the “Methods” section), with representative input (IB) and ubiquitin-immunoprecipated (IP) blots for Nrf2. Bar graph shows mean ± S.E.M. immunoreactivity (fold changes in optical densities, OD with untreated group set at 100 %) of Ub-Nrf2/total Nrf2 normalized to β-actin. § p < 0.001 for comparison with untreated control (Student’s t tests). All data were from three to four independent experimentsBack to article page