Figure 4.

Treatment with Uncaria tomentosa inhibits ERK and Akt phosphorylation and promotes caspase cleavage in B16-BL6 cells: (A) B16-BL6 cells were treated with ethanol or PBS extracts of Uncaria tomentosa or 10⁻⁶ M Camptothecin for 48 h and cell lysates were collected and subjected to immunoblot analysis using ERK (threonine 202/204) phosphate, ERK1/2, Akt (serine 473) phosphate, Akt, β-tubulin, and caspase-3 antibodies. The relative intensities of the phosphorylated bands, normalized for the level of total protein or the relative level of cleaved/uncleaved forms, were determined by densitometry and the fold change for 3 independent experiments, as shown in the bar graphs. Differences compared to the control were considered significant (*) when p ≤ 0.05 by a Tukey post hoc test; (B) the relative activity of the indicated transcription factor pathways for B16-BL6 cells treated with 100 µg/mL of the ethanol extract of Uncaria tomentosa for 24 h was determined using the Cignal transcriptional profile assay. The relative luminescence was corrected for a constitutive control plasmid and fold changes between the Uncaria- and vehicle only-treated controls are reported for two experiments.